# ent

id: cord-002179-v8lpw4r7
type: PROTEIN
entity:
  DENV host factors polypyrimidine tract binding protein 1 PTBP1 interleukin enhancer binding factor 3 ILF3 calreticulin CALR calnexin


id: cord-002179-v8lpw4r7
type: PROTEIN
entity:
  octamer binding protein NONO Embryonic stem cell specific 5 hydroxymethylcytosine binding protein HMCES RBMX RNA binding motif protein X chromosome hnRNP M


id: cord-003006-lk2ny1wd
type: PROTEIN
entity:
  nuclear factor kappa B kinase subunit epsilon IRF interferon regulatory factor MAVS mitochondrial antiviral signalling protein MDA5 melanoma differentiation associated protein 5 NP nucleoprotein PACT protein activator


id: cord-003006-lk2ny1wd
type: PROTEIN
entity:
  nuclear factor kappa B activator TBK1 tumour necrosis factor receptor associated factor family member


id: cord-003006-lk2ny1wd
type: PROTEIN
entity:
  nuclear factor kappa B activator binding kinase 1 TRAF3 tumour necrosis factor receptor associated factor 3 VP viral protein vRNA


id: cord-007383-5yb3dxse
type: PROTEIN
entity:
  HRP conjugated goat anti mouse IgG Santa Cruz Biotechnology Santa Cruz CA USA 3 3 5 5 tetramethylbenzidine peroxidase substrate


id: cord-007383-5yb3dxse
type: ORG
entity:
  the Seoul National University Hospital and International Vaccine Institute Institutional Animal Care and Use Committee


id: cord-007383-5yb3dxse
type: WORK_OF_ART
entity:
  Preventing Disease and Effective Treatment with Favipiravir DNA Vaccine Delivery and Improved Immunogenicity


id: cord-002248-92pzqj35
type: PROTEIN
entity:
  Cell Signaling Technology Anti GTF2H1 p62 mouse monoclonal antibody anti GTF2H2 p44 mouse polyclonal antibody


id: cord-002248-92pzqj35
type: ORG
entity:
  the Guide for the Care and Use of Laboratory Animals Institute of Laboratory Animal Resources National Research Council National Academy of Sciences 1996


id: cord-000680-vsgd9v1w
type: GGP
entity:
  pntd 0001676 sha 7d3b1ce33b6c181f3509a9cfa9d6aab1e53c2eaa doc_id 680 cord_uid vsgd9v1w BACKGROUND Elevation of aspartate aminotransferase


id: cord-000680-vsgd9v1w
type: ORG
entity:
  Control World Health Organization Regional Office for Southeast Asia 2011 Comprehensive Guidelines for Prevention and Control of Dengue


id: cord-268329-apl6n6jl
type: GGP
entity:
  cytokines tumor necrosis factor alpha TNF α interferon gamma IFN γ interleukin 17 IL 17 and C X C motif chemokine


id: cord-003243-u744apzw
type: WORK_OF_ART
entity:
  Sequential Modelling of the Effects of Mass Drug Treatments on Anopheline Mediated Lymphatic Filariasis Infection


id: cord-004247-lagv3tp7
type: WORK_OF_ART
entity:
  Generates Antibody to Pneumocystis jirovecii Vaccine Induced Immunogenicity and Protection Against Pneumocystis Pneumonia


id: cord-004247-lagv3tp7
type: WORK_OF_ART
entity:
  The Role of Antibodies in the Defense Against Tuberculosis Tuberculosis Current Issues in Diagnosis and Malaria


id: cord-001812-ov1qssnu
type: WORK_OF_ART
entity:
  Formalin Inactivation of Japanese Encephalitis Virus Vaccine Alters the Antigenicity and Immunogenicity of a Neutralization Epitope


id: cord-308343-crjjhpl1
type: ORG
entity:
  G Federation of Animal Science Societies Guide for the Care and Use of Agricultural Animals in Research and


id: cord-000113-d0eur1hq
type: PROTEIN
entity:
  GenePix Pro 6 1 software Molecular Devices Statistical analysis of the data was conducted using DetectiV software 64 doi 10 1371 journal pntd 0000530


id: cord-000113-d0eur1hq
type: WORK_OF_ART
entity:
  Emerging Technologies for the Detection of Rabies Virus Challenges and Hopes in the 21st Century date 2009


id: cord-000113-d0eur1hq
type: CHEMICAL
entity:
  N P and G gene sequences Primary structure of leader RNA and nucleoprotein genes of the rabies genome segmented homology with


id: cord-272250-asuxx1ln
type: ORG
entity:
  Amazon Human Rabies Prevention 2008 Recommendations of the Advisory Committee for Immunization Practices Nipah


id: cord-000283-7s6283y5
type: PROTEIN
entity:
  cell permeable nonpolar H 2 O 2 sensitive probe 5 and 6 chlromethyl 20 70 dichlorodihydrofluoresceindiacetate CM H2DCFDA Sigma USA


id: cord-000283-7s6283y5
type: ORG
entity:
  Committee for the Purpose of Control and Supervision of Experiments on Animals CPCSEA Ministry of Environment and Forestry Government


id: cord-003389-0yh5k6jk
type: CELL_LINE
entity:
  human CD34 stem cell transfer 4 BLT NSG mice that had been engrafted with human fetal liver derived CD34 stem cells


id: cord-003389-0yh5k6jk
type: CELL_LINE
entity:
  MassSieve panning MS MS peptide data for proteins The Collaborative Cross a community resource for the genetic analysis of complex traits The utility of the new generation of humanized mice to study HIV 1


id: cord-003389-0yh5k6jk
type: ORG
entity:
  Translational Rodent Models for Research on Parasitic Protozoa A Review of Confounders and Possibilities


id: cord-002581-r7mskri0
type: ORG
entity:
  Microcephaly Brazil Interim Guidelines for the Evaluation and Testing of Infants with Possible Congenital Zika Virus Infection United States Interim Guidelines for Pregnant Women During a Zika Virus Outbreak United States Human


id: cord-002581-r7mskri0
type: CHEMICAL
entity:
  Nieto Lucas Avelino Silva Vivian I Trindade Mateus Nogueira Juliana Oliveira Consuelo S Maestri Alvino Felix Alvina


id: cord-002581-r7mskri0
type: DISEASE
entity:
  somatic mutations Class switch recombination and somatic hypermutation of virus neutralizing antibodies


id: cord-340939-ikomc19t
type: ORG
entity:
  the United States Public Health Service Policy on Humane Care and Use of Laboratory Animals Protocol


id: cord-310870-w8wu8vno
type: ORG
entity:
  Global Harmonization Task Force Essencial Principles of Safety and Performance of Medical Devices Chemical


id: cord-276850-tnlyk0wz
type: PROTEIN
entity:
  70 kDa 100 and 100 respectively 90 kDa 86 and 88 Table doi 10 1371 journal pntd 0004016 g004 respectively 100 kDa 76 and 82 respectively 38 kDa 74 and 62 respectively 40 kDa 64 and 56 respectively 52 kDa 58 and 56 respectively 30 kDa 50 and 34 respectively 55 kDa 48 and 48


id: cord-294798-ji3p0l4j
type: ORG
entity:
  the Chikungunya Virus Caribbean Outbreak Reveals Novel Evolutionary Genomic Elements Emergence of Human Arboviral Diseases


id: cord-294798-ji3p0l4j
type: WORK_OF_ART
entity:
  Improving the Accuracy of Demographic and Molecular Clock Model Comparison While Accommodating Phylogenetic Uncertainty Zika


id: cord-355469-ojop6i4k
type: DNA
entity:
  5 CAATTTCCACTCGTTCGTTG 3 5 GATGGTGTGGAAACGG ATAC 3 Eurofins Genomics Inc and FAM 5 GACCAGACCAGATACGTGGAATCC 3 TAMRA Sigma Aldrich Co LLC


id: cord-309587-xc4jaw31
type: ORG
entity:
  Public Health and Social Welfare Tanzania National Parks Tanzania Wildlife Research Institute Ngorongoro Conservation Area Authority Tanzania Commission for Science and Technology


id: cord-286255-ded5t1ai
type: GGP
entity:
  malaria 9 11 12 13 18 and typhoid fever 9 10 12 13 15 were not part of our diagnostic algorithm as they are only occasionally


id: cord-281456-3dlsbr7c
type: PROTEIN
entity:
  tumor necrosis factor alpha TNFa mannan binding lectin 2 MBL2 Cytotoxic T Lymphocyte Antigen 4 CTLA4 transforming growth factor b TGFb DC SIGN and human leukocyte antigen HLA class I and II alleles


id: cord-296226-ugeupo3u
type: WORK_OF_ART
entity:
  the WHO Strategic Technical Advisory Group on Neglected Tropical Diseases and Strategic Advisory Group of Experts Working Group for Dengvaxia


id: cord-296226-ugeupo3u
type: ORG
entity:
  the World Health Organization World Health Organization Global Vector Control Response World Health Organization Framework


id: cord-296226-ugeupo3u
type: ORG
entity:
  Ministry of National Development Centre for Liveable Cities Singapore Sustainable Singapore Blueprint Forging a Greener Tomorrow


id: cord-345494-8lcdx719
type: ORG
entity:
  the Guide for the Care and Use of Laboratory Animals Institute of Laboratory Animals Resources National Research Council National Academy Press 1996 Oligonucleotide


id: cord-345494-8lcdx719
type: ORG
entity:
  the Detection of Middle East Respiratory Syndrome Coronavirus A Portable Reverse Transcription Recombinase Polymerase Amplification Assay for Rapid Detection of Foot and Mouth Disease Virus


# bib

id: cord-000113-d0eur1hq
title: Emerging Technologies for the Detection of Rabies Virus: Challenges and Hopes in the 21st Century
author: Fooks, Anthony R.
date: 2009-09-29
txt: ./txt/cord-000113-d0eur1hq.txt
cache: ./cache/cord-000113-d0eur1hq.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2745658/
doi: 10.1371/journal.pntd.0000530
summary:
  The advent of molecular biology and new technological initiatives that combine advances in biology with other disciplines will support the development of techniques capable of high throughput testing with a low turnaround time for rabies diagnosis. The advent of molecular biology and new technological initiatives that combine advances in biology with other disciplines will support the development of techniques capable of high throughput testing with a low turnaround time for rabies diagnosis. Another method for the detection of rabies virus antigen from postmortem samples is a recently developed rapid immunodiagwww.plosntds.org nostic test (RIDT) based on the principles of immunochromatography [13] . Development of RT-LAMP assays for use in diagnosis and surveillance is challenged by the considerable sequence variation observed within the rabies virus genome [44] that can frustrate specific primer design. Currently, high-throughput rabies virus molecular detection methods augment standard diagnostic tests or are in the process of development and refinement for use alone.

abstract:
  The diagnosis of rabies is routinely based on clinical and epidemiological information, especially when exposures are reported in rabies-endemic countries. Diagnostic tests using conventional assays that appear to be negative, even when undertaken late in the disease and despite the clinical diagnosis, have a tendency, at times, to be unreliable. These tests are rarely optimal and entirely dependent on the nature and quality of the sample supplied. In the course of the past three decades, the application of molecular biology has aided in the development of tests that result in a more rapid detection of rabies virus. These tests enable viral strain identification from clinical specimens. Currently, there are a number of molecular tests that can be used to complement conventional tests in rabies diagnosis. Indeed the challenges in the 21st century for the development of rabies diagnostics are not of a technical nature; these tests are available now. The challenges in the 21st century for diagnostic test developers are two-fold: firstly, to achieve internationally accepted validation of a test that will then lead to its acceptance by organisations globally. Secondly, the areas of the world where such tests are needed are mainly in developing regions where financial and logistical barriers prevent their implementation. Although developing countries with a poor healthcare infrastructure recognise that molecular-based diagnostic assays will be unaffordable for routine use, the cost/benefit ratio should still be measured. Adoption of rapid and affordable rabies diagnostic tests for use in developing countries highlights the importance of sharing and transferring technology through laboratory twinning between the developed and the developing countries. Importantly for developing countries, the benefit of molecular methods as tools is the capability for a differential diagnosis of human diseases that present with similar clinical symptoms. Antemortem testing for human rabies is now possible using molecular techniques. These barriers are not insurmountable and it is our expectation that if such tests are accepted and implemented where they are most needed, they will provide substantial improvements for rabies diagnosis and surveillance. The advent of molecular biology and new technological initiatives that combine advances in biology with other disciplines will support the development of techniques capable of high throughput testing with a low turnaround time for rabies diagnosis.


id: cord-000283-7s6283y5
author: Nazmi, Arshed
date: 2010-11-23
txt: ./txt/cord-000283-7s6283y5.txt
cache: ./cache/cord-000283-7s6283y5.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990691/
doi: 10.1371/journal.pntd.0000892
summary:
  We intend to show that these specifically designed Vivo-Morpholinos are effective in countering the viral load in the body, thereby imparting significant protection to the animals that were infected with a lethal dose of JEV. Similarly, E glycoprotein level showed significant increase in JEV-infected and JEV+SC-MO groups when compared to Sham (p,0.01) which were then drastically reduced following 39 and 59 MO treatments (p,0.01) (Figure 3B-D) . CBA performed to check the proinflammatory cytokines levels in the brain homogenates obtained from different treatments showed that levels of MCP-1, IFN-c, TNF-a, and IL-6 were found to be significantly increased in both JEV and JEV+SC-MO groups when compared to Sham infected groups (p,0.01). doi:10.1371/journal.pntd.0000892.g002 Vivo-Morpholino in Japanese Encephalitis www.plosntds.org JEV+SC-MO groups when compared to Sham (p,0.01). Increases were observed in the ROS levels in the brain samples of JEVinfected and JEV+SC-MO groups in comparison to Sham, that were reduced following 39 and 59 MO treatments.

title:
  Antiviral and Neuroprotective Role of Octaguanidinium Dendrimer-Conjugated Morpholino Oligomers in Japanese Encephalitis

abstract:
  BACKGROUND: Japanese encephalitis (JE), caused by a mosquito-borne flavivirus, is endemic to the entire south-east Asian and adjoining regions. Currently no therapeutic interventions are available for JE, thereby making it one of the most dreaded encephalitides in the world. An effective way to counter the virus would be to inhibit viral replication by using anti-sense molecules directed against the viral genome. Octaguanidinium dendrimer-conjugated Morpholino (or Vivo-Morpholino) are uncharged anti-sense oligomers that can enter cells of living organisms by endocytosis and subsequently escape from endosomes into the cytosol/nuclear compartment of cells. We hypothesize that Vivo-Morpholinos generated against specific regions of 3′ or 5′ untranslated regions of JEV genome, when administered in an experimental model of JE, will have significant antiviral and neuroprotective effect. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with JEV (GP78 strain) followed by intraperitoneal administration of Morpholinos (5 mg/kg body weight) daily for up to five treatments. Survivability of the animals was monitored for 15 days (or until death) following which they were sacrificed and their brains were processed either for immunohistochemical staining or protein extraction. Plaque assay and immunoblot analysis performed from brain homogenates showed reduced viral load and viral protein expression, resulting in greater survival of infected animals. Neuroprotective effect was observed by thionin staining of brain sections. Cytokine bead array showed reduction in the levels of proinflammatory cytokines in brain following Morpholino treatment, which were elevated after infection. This corresponded to reduced microglial activation in brain. Oxidative stress was reduced and certain stress-related signaling molecules were found to be positively modulated following Morpholino treatment. In vitro studies also showed that there was decrease in infective viral particle production following Morpholino treatment. CONCLUSIONS/SIGNIFICANCE: Administration of Vivo-Morpholino effectively resulted in increased survival of animals and neuroprotection in a murine model of JE. Hence, these oligomers represent a potential antiviral agent that merits further evaluation.


id: cord-000625-cpjlzutk
title: Detection of Mycobacterium ulcerans by the Loop Mediated Isothermal Amplification Method
author: Ablordey, Anthony
date: 2012-04-03
txt: ./txt/cord-000625-cpjlzutk.txt
cache: ./cache/cord-000625-cpjlzutk.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3317900/
doi: 10.1371/journal.pntd.0001590
summary:
  In order to develop a field applicable technique that offers high detection sensitivity and specificity for the diagnosis of BU, we explored the use of the pocket warmer LAMP (pwLAMP) technique, a DNA amplification method using isothermal conditions (60uC) provided by a disposable pocket warmer [34] . In order to develop a simple and rapid test that can be used to diagnose Buruli ulcer under field conditions, we modified the conventional LAMP assay by using a disposable pocket warmer as a heating device for generating a constant temperature for the test reaction and employed the use of crude sample preparations consisting of boiled and unboiled extracts of the clinical specimen instead of using purified DNA as the diagnostic specimen. Thirty clinical specimens from suspected Buruli ulcer patients were investigated by the modified LAMP (or pocket warmer LAMP) and the conventional LAMP, as well as IS2404 PCR, a reference method for the detection of Mycobacterium ulcerans.

abstract:
  BACKGROUND: Buruli ulcer (BU) caused by Mycobacterium ulcerans (M. ulcerans) has emerged as an important public health problem in several rural communities in sub-Saharan Africa. Early diagnosis and prompt treatment are important in preventing disfiguring complications associated with late stages of the disease progression. Presently there is no simple and rapid test that is appropriate for early diagnosis and use in the low-resource settings where M. ulcerans is most prevalent. METHODOLOGY: We compared conventional and pocket warmer loop mediated isothermal amplification (LAMP) methods (using a heat block and a pocket warmer respectively as heat source for amplification reaction) for the detection of M. ulcerans in clinical specimens. The effect of purified and crude DNA preparations on the detection rate of the LAMP assays were also investigated and compared with that of IS2404 PCR, a reference assay for the detection of M. ulcerans. Thirty clinical specimens from suspected BU cases were examined by LAMP and IS2404 PCR. PRINCIPAL FINDINGS: The lower detection limit of both LAMP methods at 60°C was 300 copies of IS2404 and 30 copies of IS2404 for the conventional LAMP at 65°C. When purified DNA extracts were used, both the conventional LAMP and IS2404 PCR concordantly detected 21 positive cases, while the pocket warmer LAMP detected 19 cases. Nine of 30 samples were positive by both the LAMP assays as well as IS2404 PCR when crude extracts of clinical specimens were used. CONCLUSION/SIGNIFICANCE: The LAMP method can be used as a simple and rapid test for the detection of M. ulcerans in clinical specimens. However, obtaining purified DNA, as well as generating isothermal conditions, remains a major challenge for the use of the LAMP method under field conditions. With further improvement in DNA extraction and amplification conditions, the pwLAMP could be used as a point of care diagnostic test for BU


id: cord-000680-vsgd9v1w
author: Lee, Linda K.
date: 2012-06-05
txt: ./txt/cord-000680-vsgd9v1w.txt
cache: ./cache/cord-000680-vsgd9v1w.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3367991/
doi: 10.1371/journal.pntd.0001676
summary:
  We aimed to assess the clinical relevance and discriminatory value of AST or ALT for dengue hemorrhagic fever (DHF) and severe dengue. There was significant overlap in AST and ALT values among patients with dengue with or without warning signs and severe dengue, and between those with DF and DHF. In this study, we aimed to evaluate the clinical relevance of elevated AST and ALT levels and correlate liver aminotransferase levels with dengue severity according to WHO 1997 and 2009 classifications. We performed a subgroup analysis for median maximum AST and ALT values stratified by febrile (days 1-3 of illness), critical (days 4-6), and convalescent (days 7-10) phases as defined by WHO 2009 [1] and compared across dengue severity classification according to WHO 1997 [9] and 2009 [1] . In conclusion, elevated aminotransferase levels were associated with DHF/DSS and severe dengue in our cohort of adult patients with confirmed dengue.

title:
  Clinical Relevance and Discriminatory Value of Elevated Liver Aminotransferase Levels for Dengue Severity

abstract:
  BACKGROUND: Elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) is prominent in acute dengue illness. The World Health Organization (WHO) 2009 dengue guidelines defined AST or ALT≥1000 units/liter (U/L) as a criterion for severe dengue. We aimed to assess the clinical relevance and discriminatory value of AST or ALT for dengue hemorrhagic fever (DHF) and severe dengue. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively studied and classified polymerase chain reaction positive dengue patients from 2006 to 2008 treated at Tan Tock Seng Hospital, Singapore according to WHO 1997 and 2009 criteria for dengue severity. Of 690 dengue patients, 31% had DHF and 24% severe dengue. Elevated AST and ALT occurred in 86% and 46%, respectively. Seven had AST or ALT≥1000 U/L. None had acute liver failure but one patient died. Median AST and ALT values were significantly higher with increasing dengue severity by both WHO 1997 and 2009 criteria. However, they were poorly discriminatory between non-severe and severe dengue (e.g., AST area under the receiver operating characteristic [ROC] curve = 0.62; 95% confidence interval [CI]: 0.57–0.67) and between dengue fever (DF) and DHF (AST area under the ROC curve = 0.56; 95% CI: 0.52–0.61). There was significant overlap in AST and ALT values among patients with dengue with or without warning signs and severe dengue, and between those with DF and DHF. CONCLUSIONS: Although aminotransferase levels increased in conjunction with dengue severity, AST or ALT values did not discriminate between DF and DHF or non-severe and severe dengue.


id: cord-001074-qevosik3
author: Selvarajah, Suganya
date: 2013-09-12
txt: ./txt/cord-001074-qevosik3.txt
cache: ./cache/cord-001074-qevosik3.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3772074/
doi: 10.1371/journal.pntd.0002423
summary:
  C9 was determined to be a potent virus neutralizing antibody and a biosensor antibody binding study demonstrated it recognized residues on intact CHIKV VLPs. Shotgun mutagenesis alanine scanning of 98 percent of the residues in the E1 and E2 glycoproteins of CHIKV envelope showed that the epitope bound by C9 included amino-acid 162 in the acid-sensitive region (ASR) of the CHIKV E2 glycoprotein. The neutralizing epitope bound by C9 mapped to the acid-sensitive region (ASR) that is critical for the rearrangement of CHIKV E2 during fusion and viral entry into host cells. Therefore, C9 is a potent neutralizing antibody that can therapeutically protect wild-type neonate mice from a lethal dose of virus at 8 and 18 hours post CHIKV inoculation. This study describes the isolation and characterization of two human monoclonal antibodies, C9 and E8, from CHIKV infected and recovered individuals.

title:
  A Neutralizing Monoclonal Antibody Targeting the Acid-Sensitive Region in Chikungunya Virus E2 Protects from Disease

abstract:
  The mosquito-borne alphavirus, chikungunya virus (CHIKV), has recently reemerged, producing the largest epidemic ever recorded for this virus, with up to 6.5 million cases of acute and chronic rheumatic disease. There are currently no licensed vaccines for CHIKV and current anti-inflammatory drug treatment is often inadequate. Here we describe the isolation and characterization of two human monoclonal antibodies, C9 and E8, from CHIKV infected and recovered individuals. C9 was determined to be a potent virus neutralizing antibody and a biosensor antibody binding study demonstrated it recognized residues on intact CHIKV VLPs. Shotgun mutagenesis alanine scanning of 98 percent of the residues in the E1 and E2 glycoproteins of CHIKV envelope showed that the epitope bound by C9 included amino-acid 162 in the acid-sensitive region (ASR) of the CHIKV E2 glycoprotein. The ASR is critical for the rearrangement of CHIKV E2 during fusion and viral entry into host cells, and we predict that C9 prevents these events from occurring. When used prophylactically in a CHIKV mouse model, C9 completely protected against CHIKV viremia and arthritis. We also observed that when administered therapeutically at 8 or 18 hours post-CHIKV challenge, C9 gave 100% protection in a pathogenic mouse model. Given that targeting this novel neutralizing epitope in E2 can potently protect both in vitro and in vivo, it is likely to be an important region both for future antibody and vaccine-based interventions against CHIKV.


id: cord-001365-6u80p5sj
title: A Novel MVA Vectored Chikungunya Virus Vaccine Elicits Protective Immunity in Mice
author: Weger-Lucarelli, James
date: 2014-07-24
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4109897/
doi: 10.1371/journal.pntd.0002970
abstract:
  BACKGROUND: Chikungunya virus (CHIKV) is a re-emerging arbovirus associated with febrile illness often accompanied by rash and arthralgia that may persist for several years. Outbreaks are associated with high morbidity and create a public health challenge for countries affected. Recent outbreaks have occurred in both Europe and the Americas, suggesting CHIKV may continue to spread. Despite the sustained threat of the virus, there is no approved vaccine or antiviral therapy against CHIKV. Therefore, it is critical to develop a vaccine that is both well tolerated and highly protective. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we describe the construction and characterization of a modified Vaccinia virus Ankara (MVA) virus expressing CHIKV E3 and E2 proteins (MVA-CHIK) that protected several mouse models from challenge with CHIKV. In particular, BALB/c mice were completely protected against viremia upon challenge with CHIKV after two doses of MVA-CHIK. Additionally, A129 mice (deficient in IFNα/β) were protected from viremia, footpad swelling, and mortality. While high anti-virus antibodies were elicited, low or undetectable levels of neutralizing antibodies were produced in both mouse models. However, passive transfer of MVA-CHIK immune serum to naïve mice did not protect against mortality, suggesting that antibodies may not be the main effectors of protection afforded by MVA-CHIK. Furthermore, depletion of CD4(+), but not CD8(+) T-cells from vaccinated mice resulted in 100% mortality, implicating the indispensable role of CD4(+) T-cells in the protection afforded by MVA-CHIK. CONCLUSIONS/SIGNIFICANCE: The results presented herein demonstrate the potential of MVA to effectively express CHIKV E3-E2 proteins and generate protective immune responses. Our findings challenge the assumption that only neutralizing antibodies are effective in providing protection against CHIKV, and provides a framework for the development of novel, more effective vaccine strategies to combat CHIKV.


id: cord-001484-va0teako
title: Rapid Identification of Black Grain Eumycetoma Causative Agents Using Rolling Circle Amplification
author: Ahmed, Sarah A.
date: 2014-12-04
txt: ./txt/cord-001484-va0teako.txt
cache: ./cache/cord-001484-va0teako.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4256478/
doi: 10.1371/journal.pntd.0003368
summary:
  A rapid, simple, and highly efficient molecular based method for identification of agents of black grain eumycetoma is introduced, aiming to improve diagnostic in endemic areas. Rolling circle amplification (RCA) is a powerful diagnostic method based on detection of specific nucleic-acid sequences and enzymatic amplification of circularized oligonucleotide probes under isothermal conditions [10] . The specificity of the 8 RCA probes was tested using strains of black-grain mycetoma causative species listed in table 1. Identification of mycetoma agent with phenotypic features is too limited, and physiological and biochemical techniques are laborious, time-consuming and nonspecific, whereas the currently available molecular methods based on DNA sequencing are specific but extremely expensive. We describe rolling circle amplification method for identification of black grain eumycetoma using species-specific padlock probes. In the present study we developed a simple, fast and highly specific molecular method for the identification of agents of black grain mycetoma.

abstract:
  Accurate identification of mycetoma causative agent is a priority for treatment. However, current identification tools are far from being satisfactory for both reliable diagnosis and epidemiological investigations. A rapid, simple, and highly efficient molecular based method for identification of agents of black grain eumycetoma is introduced, aiming to improve diagnostic in endemic areas. Rolling Circle Amplification (RCA) uses species-specific padlock probes and isothermal DNA amplification. The tests were based on ITS sequences and developed for Falciformispora senegalensis, F. tompkinsii, Madurella fahalii, M. mycetomatis, M. pseudomycetomatis, M. tropicana, Medicopsis romeroi, and Trematosphaeria grisea. With the isothermal RCA assay, 62 isolates were successfully identified with 100% specificity and no cross reactivity or false results. The main advantage of this technique is the low-cost, high specificity, and simplicity. In addition, it is highly reproducible and can be performed within a single day.


id: cord-001642-bom9fk1y
author: Wang, Junhua
date: 2015-05-08
txt: ./txt/cord-001642-bom9fk1y.txt
cache: ./cache/cord-001642-bom9fk1y.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4425495/
doi: 10.1371/journal.pntd.0003755
summary:
  We showed that AE-fgl2(-/-) mice exhibited (as compared to AE-WT-animals) (a) a significantly lower parasite load with reduced proliferation activity, (b) an increased T cell proliferative response to ConA, (c) reduced Treg numbers and function, and (d) a persistent capacity of Th1 polarization and DC maturation. multilocularis-infected fgl2 -/mice and control WT littermates were analyzed after 1 and 4 months p.i. with respect to parasite weight and the expression of em14-3-3 as a marker for cellular proliferation activity [24] . Quantitative RT-PCR showed that fgl2 mRNA-levels were significantly increased in CD4 + CD25 + Tregs derived from AE-WT mice, when compared to non-infected controls, while no significant changes were evident with respect to CD4 + Teffs, CD8 + T cells. To further explore the role of VF on Tregs and FGL2 secretion, respectively, spleen cells from AE-WT mice and non-infected WT controls were each cultured in the presence of VF (10 μg/mL).

title:
  Deletion of Fibrinogen-like Protein 2 (FGL-2), a Novel CD4(+) CD25(+) Treg Effector Molecule, Leads to Improved Control of Echinococcus multilocularis Infection in Mice

abstract:
  BACKGROUND: The growth potential of the tumor-like Echinococcus multilocularis metacestode (causing alveolar echinococcosis, AE) is directly linked to the nature/function of the periparasitic host immune-mediated processes. We previously showed that Fibrinogen-like-protein 2 (FGL2), a novel CD4(+)CD25(+) Treg effector molecule, was over-expressed in the liver of mice experimentally infected with E. multilocularis. However, little is known about its contribution to the control of this chronic helminth infection. METHODS/FINDINGS: Key parameters for infection outcome in E. multilocularis-infected fgl2(-/-) (AE-fgl2(-/-)) and wild type (AE-WT) mice at 1 and 4 month(s) post-infection were (i) parasite load (i. e. wet weight of parasitic metacestode tissue), and (ii) parasite cell proliferation as assessed by determining E. multilocularis 14-3-3 gene expression levels. Serum FGL2 levels were measured by ELISA. Spleen cells cultured with ConA for 48h or with E. multilocularis Vesicle Fluid (VF) for 96h were analyzed ex-vivo and in-vitro. In addition, spleen cells from non-infected WT mice were cultured with rFGL2/anti-FGL2 or rIL-17A/anti-IL-17A for further functional studies. For Treg-immune-suppression-assays, purified CD4(+)CD25(+) Treg suspensions were incubated with CD4(+) effector T cells in the presence of ConA and irradiated spleen cells as APCs. Flow cytometry and qRT-PCR were used to assess Treg, Th17-, Th1-, Th2-type immune responses and maturation of dendritic cells. We showed that AE-fgl2(-/-) mice exhibited (as compared to AE-WT-animals) (a) a significantly lower parasite load with reduced proliferation activity, (b) an increased T cell proliferative response to ConA, (c) reduced Treg numbers and function, and (d) a persistent capacity of Th1 polarization and DC maturation. CONCLUSIONS: FGL2 appears as one of the key players in immune regulatory processes favoring metacestode survival by promoting Treg cell activity and IL-17A production that contributes to FGL2-regulation. Prospectively, targeting FGL2 could be an option to develop an immunotherapy against AE and other chronic parasitic diseases.


id: cord-001690-cn21fgug
author: Franceschi, Valentina
date: 2015-06-18
txt: ./txt/cord-001690-cn21fgug.txt
cache: ./cache/cord-001690-cn21fgug.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4473039/
doi: 10.1371/journal.pntd.0003850
summary:
  In the present study, a new vaccination strategy approach based on three recombinant bovine herpesvirus 4 (BoHV-4) vectors, each expressing different MPXV glycoproteins, A29L, M1R and B6R were investigated in terms of protection from a lethal MPXV challenge in STAT1 knockout mice. In vivo efficacy testing of BoHV-4-A-CMV-A29LgD 106 ΔTK, BoHV-4-A-EF1α-M1RgD 106 ΔTK and BoHV-4-A-EF1α-B6RgD 106 ΔTK To test the efficacy of the vectors in vivo, we sought to determine if they could protect mice against a lethal challenge with MPXV. Since the purpose of this study was to determine the capability of BoHV-4-based viral vectors to protect STAT1 (-/-) mice against a lethal MPXV infection, the first concern was the generation of optimized expression cassettes to be integrated into the BAC-BoHV-4-A genome that were able to efficiently express A29L, M1R and B6R antigens. In summary, our findings have demonstrated that BoHV-4 based vectors can be used as vaccines to protect against a lethal MPXV challenge in mice.

title:
  BoHV-4-Based Vector Single Heterologous Antigen Delivery Protects STAT1((-/-)) Mice from Monkeypoxvirus Lethal Challenge

abstract:
  Monkeypox virus (MPXV) is the etiological agent of human (MPX). It is an emerging orthopoxvirus zoonosis in the tropical rain forest of Africa and is endemic in the Congo-basin and sporadic in West Africa; it remains a tropical neglected disease of persons in impoverished rural areas. Interaction of the human population with wildlife increases human infection with MPX virus (MPXV), and infection from human to human is possible. Smallpox vaccination provides good cross-protection against MPX; however, the vaccination campaign ended in Africa in 1980, meaning that a large proportion of the population is currently unprotected against MPXV infection. Disease control hinges on deterring zoonotic exposure to the virus and, barring that, interrupting person-to-person spread. However, there are no FDA-approved therapies against MPX, and current vaccines are limited due to safety concerns. For this reason, new studies on pathogenesis, prophylaxis and therapeutics are still of great interest, not only for the scientific community but also for the governments concerned that MPXV could be used as a bioterror agent. In the present study, a new vaccination strategy approach based on three recombinant bovine herpesvirus 4 (BoHV-4) vectors, each expressing different MPXV glycoproteins, A29L, M1R and B6R were investigated in terms of protection from a lethal MPXV challenge in STAT1 knockout mice. BoHV-4-A-CMV-A29LgD(106)ΔTK, BoHV-4-A-EF1α-M1RgD(106)ΔTK and BoHV-4-A-EF1α-B6RgD(106)ΔTK were successfully constructed by recombineering, and their capacity to express their transgene was demonstrated. A small challenge study was performed, and all three recombinant BoHV-4 appeared safe (no weight-loss or obvious adverse events) following intraperitoneal administration. Further, BoHV-4-A-EF1α-M1RgD(106)ΔTK alone or in combination with BoHV-4-A-CMV-A29LgD(106)ΔTK and BoHV-4-A-EF1α-B6RgD(106)ΔTK, was shown to be able to protect, 100% alone and 80% in combination, STAT1((-/-)) mice against mortality and morbidity. This work demonstrated the efficacy of BoHV-4 based vectors and the use of BoHV-4 as a vaccine-vector platform.


id: cord-001812-ov1qssnu
author: Fan, Yi-Chin
date: 2015-10-23
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4619746/
doi: 10.1371/journal.pntd.0004167
title:
  Formalin Inactivation of Japanese Encephalitis Virus Vaccine Alters the Antigenicity and Immunogenicity of a Neutralization Epitope in Envelope Protein Domain III

abstract:
  Formalin-inactivated Japanese encephalitis virus (JEV) vaccines are widely available, but the effects of formalin inactivation on the antigenic structure of JEV and the profile of antibodies elicited after vaccination are not well understood. We used a panel of monoclonal antibodies (MAbs) to map the antigenic structure of live JEV virus, untreated control virus (UCV), formalin-inactivated commercial vaccine (FICV), and formalin-inactivated virus (FIV). The binding activity of T16 MAb against Nakayama-derived FICV and several strains of FIV was significantly lower compared to live virus and UCV. T16 MAb, a weakly neutralizing JEV serocomplex antibody, was found to inhibit JEV infection at the post-attachment step. The T16 epitope was mapped to amino acids 329, 331, and 389 within domain III (EDIII) of the envelope (E) glycoprotein. When we explored the effect of formalin inactivation on the immunogenicity of JEV, we found that Nakayama-derived FICV, FIV, and UCV all exhibited similar immunogenicity in a mouse model, inducing anti-JEV and anti-EDII 101/106/107 epitope-specific antibodies. However, the EDIII 329/331/389 epitope-specific IgG antibody and neutralizing antibody titers were significantly lower for FICV-immunized and FIV-immunized mouse serum than for UCV-immunized. Formalin inactivation seems to alter the antigenic structure of the E protein, which may reduce the potency of commercially available JEV vaccines. Virus inactivation by H(2)O(2), but not by UV or by short-duration and higher temperature formalin treatment, is able to maintain the antigenic structure of the JEV E protein. Thus, an alternative inactivation method, such as H(2)O(2), which is able to maintain the integrity of the E protein may be essential to improving the potency of inactivated JEV vaccines.


id: cord-002179-v8lpw4r7
author: Viktorovskaya, Olga V.
date: 2016-08-24
txt: ./txt/cord-002179-v8lpw4r7.txt
cache: ./cache/cord-002179-v8lpw4r7.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4996428/
doi: 10.1371/journal.pntd.0004921
summary:
  title: Identification of RNA Binding Proteins Associated with Dengue Virus RNA in Infected Cells Reveals Temporally Distinct Host Factor Requirements Previously, we have described a high-throughput mass spectrometry method termed TUX-MS (thiouracil cross-linking mass spectrometry) to identify host factors that interact with viral RNA during a live infection in cell culture [15] . Development of a quantitative thiouridine cross-linking mass spectrometry (qTUX-MS) method for identification of proteins associated with the DENV RNA TUX-MS can be used to identify host factors by incorporating 4-thiouridine (4sU), a zero-distance cross-linker, into the viral RNA (vRNA) to enable cross-linking of proteins bound to vRNA during a live infection in cell culture [15] . Since some of hnRNPs are known to modulate cellular gene expression in response to dengue infection [60, 61] , we can not rule out that some of the observed effects on virus titers derive from their roles in regulating host mRNAs. Among the numerous qTUX-MS identified factors of interest, our study is the first to demonstrate the involvement of HMCES (or C3orf37) in viral infection.

title:
  Identification of RNA Binding Proteins Associated with Dengue Virus RNA in Infected Cells Reveals Temporally Distinct Host Factor Requirements

abstract:
  BACKGROUND: There are currently no vaccines or antivirals available for dengue virus infection, which can cause dengue hemorrhagic fever and death. A better understanding of the host pathogen interaction is required to develop effective therapies to treat DENV. In particular, very little is known about how cellular RNA binding proteins interact with viral RNAs. RNAs within cells are not naked; rather they are coated with proteins that affect localization, stability, translation and (for viruses) replication. METHODOLOGY/PRINCIPAL FINDINGS: Seventy-nine novel RNA binding proteins for dengue virus (DENV) were identified by cross-linking proteins to dengue viral RNA during a live infection in human cells. These cellular proteins were specific and distinct from those previously identified for poliovirus, suggesting a specialized role for these factors in DENV amplification. Knockdown of these proteins demonstrated their function as viral host factors, with evidence for some factors acting early, while others late in infection. Their requirement by DENV for efficient amplification is likely specific, since protein knockdown did not impair the cell fitness for viral amplification of an unrelated virus. The protein abundances of these host factors were not significantly altered during DENV infection, suggesting their interaction with DENV RNA was due to specific recruitment mechanisms. However, at the global proteome level, DENV altered the abundances of proteins in particular classes, including transporter proteins, which were down regulated, and proteins in the ubiquitin proteasome pathway, which were up regulated. CONCLUSIONS/SIGNIFICANCE: The method for identification of host factors described here is robust and broadly applicable to all RNA viruses, providing an avenue to determine the conserved or distinct mechanisms through which diverse viruses manage the viral RNA within cells. This study significantly increases the number of cellular factors known to interact with DENV and reveals how DENV modulates and usurps cellular proteins for efficient amplification.


id: cord-002248-92pzqj35
author: Terasaki, Kaori
date: 2016-10-06
txt: ./txt/cord-002248-92pzqj35.txt
cache: ./cache/cord-002248-92pzqj35.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5053439/
doi: 10.1371/journal.pntd.0005047
summary:
  Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice, compared with its parental virus MP-12, highlighting the contribution of NSs-mediated general transcription inhibition towards RVFV virulence. Each carried mutations in NSs that specifically targeted its general transcription inhibition function without affecting its ability to degrade PKR and inhibit IFN-β promoter induction, through its interaction with Sin3-associated protein 30, a part of the repressor complex at the IFN-β promoter. Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice, Both NSs mutants retained some NSs functions, including degradation of PKR and SAP30 binding, and yet these NSs mutants and wt NSs showed different levels of general transcriptional suppression activities in virus-infected cells.

title:
  Mechanistic Insight into the Host Transcription Inhibition Function of Rift Valley Fever Virus NSs and Its Importance in Virulence

abstract:
  Rift Valley fever virus (RVFV), a member of the genus Phlebovirus within the family Bunyaviridae, causes periodic outbreaks in livestocks and humans in countries of the African continent and Middle East. RVFV NSs protein, a nonstructural protein, is a major virulence factor that exhibits several important biological properties. These include suppression of general transcription, inhibition of IFN-β promoter induction and degradation of double-stranded RNA-dependent protein kinase R. Although each of these biological functions of NSs are considered important for countering the antiviral response in the host, the individual contributions of these functions towards RVFV virulence remains unclear. To examine this, we generated two RVFV MP-12 strain-derived mutant viruses. Each carried mutations in NSs that specifically targeted its general transcription inhibition function without affecting its ability to degrade PKR and inhibit IFN-β promoter induction, through its interaction with Sin3-associated protein 30, a part of the repressor complex at the IFN-β promoter. Using these mutant viruses, we have dissected the transcription inhibition function of NSs and examined its importance in RVFV virulence. Both NSs mutant viruses exhibited a differentially impaired ability to inhibit host transcription when compared with MP-12. It has been reported that NSs suppresses general transcription by interfering with the formation of the transcription factor IIH complex, through the degradation of the p62 subunit and sequestration of the p44 subunit. Our study results lead us to suggest that the ability of NSs to induce p62 degradation is the major contributor to its general transcription inhibition property, whereas its interaction with p44 may not play a significant role in this function. Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice, compared with its parental virus MP-12, highlighting the contribution of NSs-mediated general transcription inhibition towards RVFV virulence.


id: cord-002394-n85ptr5p
author: Reddy, Vijayalakshmi
date: 2017-01-26
txt: ./txt/cord-002394-n85ptr5p.txt
cache: ./cache/cord-002394-n85ptr5p.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5268390/
doi: 10.1371/journal.pntd.0005238
summary:
  Therefore, in this study we investigated the possible occurrence of molecular mimicry between CHIKV E1 and host components using a three pronged strategy: (i) identification of homologous regions between CHIKV proteins and host tissue components using bioinformatics tools, (ii) establishing cross reactivity between serum samples obtained from CHIKV infected patients and peptides exhibiting molecular mimicry and (iii) validating the ability of the cross reactive peptides in inducing joint and muscle pathology in a mouse model. We investigated molecular mimicry in this study by using a combined approach of identifying homologous regions between CHIKV glycoprotein E1 protein and host tissue components using bioinformatics tools, the ability of these designed peptides to cross react with serum samples from CHIKV infected patients and inducing immune mediated joint and muscle pathology in a mouse model.

title:
  Molecular Mimicry between Chikungunya Virus and Host Components: A Possible Mechanism for the Arthritic Manifestations

abstract:
  BACKGROUND: Chikungunya virus (CHIKV), a reemerging pathogen causes a self limited illness characterized by fever, headache, myalgia and arthralgia. However, 10–20% affected individuals develop persistent arthralgia which contributes to considerable morbidity. The exact molecular mechanisms underlying these manifestations are not well understood. The present study investigated the possible occurrence of molecular mimicry between CHIKV E1 glycoprotein and host human components. METHODOLOGY: Bioinformatic tools were used to identify peptides of CHIKV E1 exhibiting similarity to host components. Two peptides (A&B) were identified using several bioinformatic tools, synthesised and used to validate the results obtained in silico. An ELISA was designed to assess the immunoreactivity of serum samples from CHIKV patients to these peptides. Further, experiments were conducted in a C57BL/6J experimental mouse model to investigate if peptide A and peptide B were indeed capable of inducing pathology. FINDINGS: The serum samples showed reactivity of varying degrees, indicating that these peptides are indeed being recognized by the host immune system during CHIKV infection. Further, these peptides when injected into C57BL/6J mice were able to induce significant inflammation in the muscles of C57BL/6J mice, similar to that observed in animals that were injected with CHIKV alone. Additionally, animals that were primed initially with CHIKV followed by a subsequent injection of the CHIKV peptides exhibited enhanced inflammatory pathology in the skeletal muscles as compared to animals that were injected with peptides or virus alone. Collectively these observations validate the hypothesis that molecular mimicry between CHIKV E1 protein and host proteins does contribute to pathology in CHIKV infection.


id: cord-002581-r7mskri0
title: A human inferred germline antibody binds to an immunodominant epitope and neutralizes Zika virus
author: Magnani, Diogo M.
date: 2017-06-12
txt: ./txt/cord-002581-r7mskri0.txt
cache: ./cache/cord-002581-r7mskri0.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5481143/
doi: 10.1371/journal.pntd.0005655
summary:
  title: A human inferred germline antibody binds to an immunodominant epitope and neutralizes Zika virus The isolation of neutralizing monoclonal antibodies (nmAbs) against the Zika virus (ZIKV) might lead to novel preventative strategies for infections in at-risk individuals, primarily pregnant women. Here we describe the isolation of 18 plasmablast-derived human mAbs, sorted 12 days post onset of symptoms from a ZIKV-patient in São Paulo, Brazil. Interestingly, one of these mAbs (P1F12) exhibited no nucleotide mutations when compared to its corresponding germline sequences, but still recognized a ZIKV immunodominant epitope and neutralized the virus. Virus capture assay and recombinant E protein ELISA P1F12 binding was determined by both virus capture assay (VCA) and recombinant (r)E ELISAs. The VCA plates were coated overnight with the mouse-anti-Flavivirus monoclonal antibody 4G2 (clone D1-4G2-4-15, EMD Millipore) followed by incubation with viral stocks (ZIKV or DENV). Molecular determinants of human neutralizing antibodies isolated from a patient infected with Zika virus

abstract:
  The isolation of neutralizing monoclonal antibodies (nmAbs) against the Zika virus (ZIKV) might lead to novel preventative strategies for infections in at-risk individuals, primarily pregnant women. Here we describe the characterization of human mAbs from the plasmablasts of an acutely infected patient. One of the 18 mAbs had the unusual feature of binding to and neutralizing ZIKV despite not appearing to have been diversified by affinity maturation. This mAb neutralized ZIKV (Neut(50) ~ 2 μg/ml) but did not react with any of the four dengue virus serotypes. Except for the expected junctional diversity created by the joining of the V-(D)-J genes, there was no deviation from immunoglobulin germline genes. This is a rare example of a human mAb with neutralizing activity in the absence of detectable somatic hypermutation. Importantly, binding of this mAb to ZIKV was specifically inhibited by human plasma from ZIKV-exposed individuals, suggesting that it may be of value in a diagnostic setting.


id: cord-003006-lk2ny1wd
title: Ebolaviruses: New roles for old proteins
author: Cantoni, Diego
date: 2018-05-03
txt: ./txt/cord-003006-lk2ny1wd.txt
cache: ./cache/cord-003006-lk2ny1wd.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5933699/
doi: 10.1371/journal.pntd.0006349
summary:
  These newly discovered roles are revealing new mechanisms of virus replication and pathogenicity, whilst enhancing our understanding of the broad functions of each ebolavirus viral protein (VP). Lastly, VP35 is a suppressor of RNA silencing, functionally equivalent to the human immunodeficiency virus (HIV-1) Trans-activator of transcription (Tat) protein and important for viral evasion of the innate immune response [34] . The authors propose that this mutation is likely a result of EBOV adaptation to the human host, as several viral variants have been seen to increase human cell infectivity while decreasing virus entry in nonhuman primates [83] [84] [85] . In addition, many ebolavirus proteins are seen to interact with immune cells, causing cell activation and/or cell death and facilitating both viral replication and spread (e.g., by recruiting monocytes to infected cells or by increasing vascular leakage) as well as enabling immune evasion (e.g., antibody neutralisation by sGP and by cleaved GP), roles that were previously solely attributed to VP24 and VP35.

abstract:
  In 2014, the world witnessed the largest Ebolavirus outbreak in recorded history. The subsequent humanitarian effort spurred extensive research, significantly enhancing our understanding of ebolavirus replication and pathogenicity. The main functions of each ebolavirus protein have been studied extensively since the discovery of the virus in 1976; however, the recent expansion of ebolavirus research has led to the discovery of new protein functions. These newly discovered roles are revealing new mechanisms of virus replication and pathogenicity, whilst enhancing our understanding of the broad functions of each ebolavirus viral protein (VP). Many of these new functions appear to be unrelated to the protein’s primary function during virus replication. Such new functions range from bystander T-lymphocyte death caused by VP40-secreted exosomes to new roles for VP24 in viral particle formation. This review highlights the newly discovered roles of ebolavirus proteins in order to provide a more encompassing view of ebolavirus replication and pathogenicity.


id: cord-003243-u744apzw
author: Michael, Edwin
date: 2018-10-08
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175292/
doi: 10.1371/journal.pntd.0006674
title:
  Quantifying the value of surveillance data for improving model predictions of lymphatic filariasis elimination

abstract:
  BACKGROUND: Mathematical models are increasingly being used to evaluate strategies aiming to achieve the control or elimination of parasitic diseases. Recently, owing to growing realization that process-oriented models are useful for ecological forecasts only if the biological processes are well defined, attention has focused on data assimilation as a means to improve the predictive performance of these models. METHODOLOGY AND PRINCIPAL FINDINGS: We report on the development of an analytical framework to quantify the relative values of various longitudinal infection surveillance data collected in field sites undergoing mass drug administrations (MDAs) for calibrating three lymphatic filariasis (LF) models (EPIFIL, LYMFASIM, and TRANSFIL), and for improving their predictions of the required durations of drug interventions to achieve parasite elimination in endemic populations. The relative information contribution of site-specific data collected at the time points proposed by the WHO monitoring framework was evaluated using model-data updating procedures, and via calculations of the Shannon information index and weighted variances from the probability distributions of the estimated timelines to parasite extinction made by each model. Results show that data-informed models provided more precise forecasts of elimination timelines in each site compared to model-only simulations. Data streams that included year 5 post-MDA microfilariae (mf) survey data, however, reduced each model’s uncertainty most compared to data streams containing only baseline and/or post-MDA 3 or longer-term mf survey data irrespective of MDA coverage, suggesting that data up to this monitoring point may be optimal for informing the present LF models. We show that the improvements observed in the predictive performance of the best data-informed models may be a function of temporal changes in inter-parameter interactions. Such best data-informed models may also produce more accurate predictions of the durations of drug interventions required to achieve parasite elimination. SIGNIFICANCE: Knowledge of relative information contributions of model only versus data-informed models is valuable for improving the usefulness of LF model predictions in management decision making, learning system dynamics, and for supporting the design of parasite monitoring programmes. The present results further pinpoint the crucial need for longitudinal infection surveillance data for enhancing the precision and accuracy of model predictions of the intervention durations required to achieve parasite elimination in an endemic location.


id: cord-003389-0yh5k6jk
author: Patton, John B.
date: 2018-12-12
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6306240/
doi: 10.1371/journal.pntd.0006977
title:
  Development of Onchocerca volvulus in humanized NSG mice and detection of parasite biomarkers in urine and serum

abstract:
  BACKGROUND: The study of Onchocerca volvulus has been limited by its host range, with only humans and non-human primates shown to be susceptible to the full life cycle infection. Small animal models that support the development of adult parasites have not been identified. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that highly immunodeficient NSG mice would support the survival and maturation of O. volvulus and alteration of the host microenvironment through the addition of various human cells and tissues would further enhance the level of parasite maturation. NSG mice were humanized with: (1) umbilical cord derived CD34(+) stem cells, (2) fetal derived liver, thymus and CD34(+) stem cells or (3) primary human skeletal muscle cells. NSG and humanized NSG mice were infected with 100 O. volvulus infective larvae (L3) for 4 to 12 weeks. When necropsies of infected animals were performed, it was observed that parasites survived and developed throughout the infection time course. In each of the different humanized mouse models, worms matured from L3 to advanced fourth stage larvae, with both male and female organ development. In addition, worms increased in length by up to 4-fold. Serum and urine, collected from humanized mice for identification of potential biomarkers of infection, allowed for the identification of 10 O. volvulus-derived proteins found specifically in either the urine or the serum of the humanized O. volvulus-infected NSG mice. CONCLUSIONS/SIGNIFICANCE: The newly identified mouse models for onchocerciasis will enable the development of O. volvulus specific biomarkers, screening for new therapeutic approaches and potentially studying the human immune response to infection with O. volvulus.


id: cord-003482-f1uvohf0
author: Malmlov, Ashley
date: 2019-02-04
txt: ./txt/cord-003482-f1uvohf0.txt
cache: ./cache/cord-003482-f1uvohf0.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6382173/
doi: 10.1371/journal.pntd.0007071
summary:
  Quantitative probe-based reverse transcription PCR (qRT-PCR) was performed on seruminoculated Vero cell supernatants, serum, brain, lung, liver, spleen, kidney, urinary bladder, prostate and testes from bats from both studies. Brain and testicular tissues stained with both goat polyclonal goat anti-Iba1 (green) and monoclonal 4G-2 flavivirus E specific antibodies (red) showed co-localization (yellow) of ZIKV antigen in cytoplasm of activated microglial cells with their characteristic morphology in the cerebral cortex of infected bats 10 dpi in the time course study and 28 day dpi in the pilot study (Fig 9) . Two bat infection experiments were conducted in this investigation; 1) a pilot study to determine susceptibility of Jamaican fruit bats to ZIKV infection, and 2) a time course study to better understand pathophysiology and chronology of events pertaining to the dynamics of viremia, viral tropism, replication and shedding of the virus in a New World bat species.

title:
  Experimental Zika virus infection of Jamaican fruit bats (Artibeus jamaicensis) and possible entry of virus into brain via activated microglial cells

abstract:
  The emergence of Zika virus (ZIKV) in the New World has led to more than 200,000 human infections. Perinatal infection can cause severe neurological complications, including fetal and neonatal microcephaly, and in adults there is an association with Guillain-Barré syndrome (GBS). ZIKV is transmitted to humans by Aedes sp. mosquitoes, yet little is known about its enzootic cycle in which transmission is thought to occur between arboreal Aedes sp. mosquitos and non-human primates. In the 1950s and ‘60s, several bat species were shown to be naturally and experimentally susceptible to ZIKV with acute viremia and seroconversion, and some developed neurological disease with viral antigen detected in the brain. Because of ZIKV emergence in the Americas, we sought to determine susceptibility of Jamaican fruit bats (Artibeus jamaicensis), one of the most common bats in the New World. Bats were inoculated with ZIKV PRVABC59 but did not show signs of disease. Bats held to 28 days post-inoculation (PI) had detectable antibody by ELISA and viral RNA was detected by qRT-PCR in the brain, saliva and urine in some of the bats. Immunoreactivity using polyclonal anti-ZIKV antibody was detected in testes, brain, lung and salivary glands plus scrotal skin. Tropism for mononuclear cells, including macrophages/microglia and fibroblasts, was seen in the aforementioned organs in addition to testicular Leydig cells. The virus likely localized to the brain via infection of Iba1(+) macrophage/microglial cells. Jamaican fruit bats, therefore, may be a useful animal model for the study of ZIKV infection. This work also raises the possibility that bats may have a role in Zika virus ecology in endemic regions, and that ZIKV may pose a wildlife disease threat to bat populations.


id: cord-004247-lagv3tp7
title: Reassessing therapeutic antibodies for neglected and tropical diseases
author: Hooft van Huijsduijnen, Rob
date: 2020-01-30
txt: ./txt/cord-004247-lagv3tp7.txt
cache: ./cache/cord-004247-lagv3tp7.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6991954/
doi: 10.1371/journal.pntd.0007860
summary:
  This mAb was protective in an in vitro, antigen-dependent, cellular cytotoxicity assay with rat macrophages or eosinophils and also in vivo during the early phase of infection Second, beyond the cell-surface proteins, schistosomes also express a large number of glycans as part of their glycoprotein and glycolipid repertoire, and an antibody response against those glycans is mounted by the infected host [80] . In addition to antibodies that directly target and inhibit the fungal pathogen, mAbs can be directed to checkpoints that control the host immune response. In addition to highlighting the potential of mAbs as therapeutics, these studies have demonstrated the diversity of inhibitory actions that mAbs can perform on cryptococcal cells, which can include opsonization and increased phagocytosis, inhibition of fungal growth, capsular polysaccharide release and biofilm formation, antibody-mediated target cleavage, and augmentation of the host response [104] [105] [106] [107] .

abstract:
  In the past two decades there has been a significant expansion in the number of new therapeutic monoclonal antibodies (mAbs) that are approved by regulators. The discovery of these new medicines has been driven primarily by new approaches in inflammatory diseases and oncology, especially in immuno-oncology. Other recent successes have included new antibodies for use in viral diseases, including HIV. The perception of very high costs associated with mAbs has led to the assumption that they play no role in prophylaxis for diseases of poverty. However, improvements in antibody-expression yields and manufacturing processes indicate this is a cost-effective option for providing protection from many types of infection that should be revisited. Recent technology developments also indicate that several months of protection could be achieved with a single dose. Moreover, new methods in B cell sorting now enable the systematic identification of high-quality antibodies from humanized mice, or patients. This Review discusses the potential for passive immunization against schistosomiasis, fungal infections, dengue, and other neglected diseases.


id: cord-007383-5yb3dxse
author: Kang, Jun-Gu
date: 2020-03-20
txt: ./txt/cord-007383-5yb3dxse.txt
cache: ./cache/cord-007383-5yb3dxse.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7112229/
doi: 10.1371/journal.pntd.0007813
summary:
  title: Vaccination with single plasmid DNA encoding IL-12 and antigens of severe fever with thrombocytopenia syndrome virus elicits complete protection in IFNAR knockout mice Immunization of NS antigen with Freund''s adjuvant in C57BL/6 mice, which are naturally resistant to SFTSV but partially mimic human infections [12] , failed to enhance viral clearance, although it induced high titer of anti-NS antibodies and significantly elevated IFN-γ levels in sera upon viral challenge [9] . Vaccination of pSFTSV-IL12 provided complete protection of IFNAR KO mice upon lethal SFTSV challenge, whereas immunization with pSFTSV elicits only partial protection, indicating that antigen-specific cellular immune responses enhanced by co-expression of IL-12 could play a significant role in protection against lethal SFTSV infection. Since we observed significant elevation of T cell responses specific to the viral antigens in IFNAR KO mice immunized with pSFTSV-IL12 DNA vaccine, we tested whether it could provide protective immunity against lethal SFTSV infection.

title:
  Vaccination with single plasmid DNA encoding IL-12 and antigens of severe fever with thrombocytopenia syndrome virus elicits complete protection in IFNAR knockout mice

abstract:
  Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by SFTS virus (SFTSV) infection. Despite a gradual increase of SFTS cases and high mortality in endemic regions, no specific viral therapy nor vaccine is available. Here, we developed a single recombinant plasmid DNA encoding SFTSV genes, Gn and Gc together with NP-NS fusion antigen, as a vaccine candidate. The viral antigens were fused with Fms-like tyrosine kinase-3 ligand (Flt3L) and IL-12 gene was incorporated into the plasmid to enhance cell-mediated immunity. Vaccination with the DNA provides complete protection of IFNAR KO mice upon lethal SFTSV challenge, whereas immunization with a plasmid without IL-12 gene resulted in partial protection. Since we failed to detect antibodies against surface glycoproteins, Gn and Gc, in the immunized mice, antigen-specific cellular immunity, as confirmed by enhanced antigen-specific T cell responses, might play major role in protection. Finally, we evaluated the degree of protective immunity provided by protein immunization of the individual glycoprotein, Gn or Gc. Although both protein antigens induced a significant level of neutralizing activity against SFTSV, Gn vaccination resulted in relatively higher neutralizing activity and better protection than Gc vaccination. However, both antigens failed to provide complete protection. Given that DNA vaccines have failed to induce sufficient immunogenicity in human trials when compared to protein vaccines, optimal combinations of DNA and protein elements, proper selection of target antigens, and incorporation of efficient adjuvant, need to be further investigated for SFTSV vaccine development.


id: cord-012911-d6ct94d9
title: National reporting of deaths after enhanced Ebola surveillance in Sierra Leone
author: Jalloh, Mohamed F.
date: 2020-08-18
txt: ./txt/cord-012911-d6ct94d9.txt
cache: ./cache/cord-012911-d6ct94d9.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480832/
doi: 10.1371/journal.pntd.0008624
summary:
  In August 2014, the Government of Sierra Leone repurposed an existing national, toll-free telephone line (1-1-7 system) for communities to report all deaths and suspected Ebola patients as part of the epidemic response [13] . To inform strategies for improving routine surveillance of deaths, in April 2017, we then conducted a cross-sectional, telephone-based survey with individuals aged 18 years and above who reported a death to the 1-1-7 system after the end of enhanced Ebola surveillance in Sierra Leone. The monthly aggregated data of deaths reported to the 1-1-7 system showed a sharp decline after the 2014-2015 Ebola epidemic ended in Sierra Leone compared to the post-outbreak enhanced mortality surveillance period. In the telephone survey we identified motivations related to death reporting that have practical implications for improving routine mortality surveillance in a post-Ebola-outbreak setting.

abstract:
  BACKGROUND: Sierra Leone experienced the largest documented epidemic of Ebola Virus Disease in 2014–2015. The government implemented a national tollfree telephone line (1-1-7) for public reporting of illness and deaths to improve the detection of Ebola cases. Reporting of deaths declined substantially after the epidemic ended. To inform routine mortality surveillance, we aimed to describe the trends in deaths reported to the 1-1-7 system and to quantify people’s motivations to continue reporting deaths after the epidemic. METHODS: First, we described the monthly trends in the number of deaths reported to the 1-1-7 system between September 2014 and September 2019. Second, we conducted a telephone survey in April 2017 with a national sample of individuals who reported a death to the 1-1-7 system between December 2016 and April 2017. We described the reported deaths and used ordered logistic regression modeling to examine the potential drivers of reporting motivations. FINDINGS: Analysis of the number of deaths reported to the 1-1-7 system showed that 12% of the expected deaths were captured in 2017 compared to approximately 34% in 2016 and over 100% in 2015. We interviewed 1,291 death reporters in the survey. Family members reported 56% of the deaths. Nearly every respondent (94%) expressed that they wanted the 1-1-7 system to continue. The most common motivation to report was to obey the government’s mandate (82%). Respondents felt more motivated to report if the decedent exhibited Ebola-like symptoms (adjusted odds ratio 2.3; 95% confidence interval 1.8–2.9). CONCLUSIONS: Motivation to report deaths that resembled Ebola in the post-outbreak setting may have been influenced by knowledge and experiences from the prolonged epidemic. Transitioning the system to a routine mortality surveillance tool may require a robust social mobilization component to match the high reporting levels during the epidemic, which exceeded more than 100% of expected deaths in 2015.


id: cord-260693-8mfuwx8l
title: The COVID-19 pandemic should not derail global vector control efforts
author: Seelig, Frederik
date: 2020-08-31
txt: ./txt/cord-260693-8mfuwx8l.txt
cache: ./cache/cord-260693-8mfuwx8l.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32866149/
doi: 10.1371/journal.pntd.0008606
abstract: nan
summary:
  However, a similar approach should also be adopted for the control of arboviral diseases of global importance, including dengue, Zika, chikungunya, and yellow fever, as recommended by the Pan-American Health Organization (PAHO) in their interim guidance on control of Aedes aegypti mosquitos during the COVID-19 pandemic [2] . The combined impact of both COVID-19 and epidemics of dengue or other vector-borne diseases (VBDs) could have potentially devastating consequences [6] . • Continue the implementation of the WHO''s global vector control response 2017-2030 (GVCR) strategy and regional policies for vector control [7, 8] , with respect to inter-and intrasectoral collaboration, engagement and mobilisation of communities, and scaling up of vector control if required, according to the implementation plan of vector control activities, while adapting activities as necessary to prevent further spread of COVID-19, in particular vector surveillance, which may need to be scaled down [9, 10] . It is vital that the COVID-19 response does not increase VBD threats in these communities by derailing global vector control efforts.


id: cord-263044-o8aosx2q
title: Potential Biases in Estimating Absolute and Relative Case-Fatality Risks during Outbreaks
author: Lipsitch, Marc
date: 2015-07-16
url: https://www.ncbi.nlm.nih.gov/pubmed/26181387/
doi: 10.1371/journal.pntd.0003846
abstract:
  Estimating the case-fatality risk (CFR)—the probability that a person dies from an infection given that they are a case—is a high priority in epidemiologic investigation of newly emerging infectious diseases and sometimes in new outbreaks of known infectious diseases. The data available to estimate the overall CFR are often gathered for other purposes (e.g., surveillance) in challenging circumstances. We describe two forms of bias that may affect the estimation of the overall CFR—preferential ascertainment of severe cases and bias from reporting delays—and review solutions that have been proposed and implemented in past epidemics. Also of interest is the estimation of the causal impact of specific interventions (e.g., hospitalization, or hospitalization at a particular hospital) on survival, which can be estimated as a relative CFR for two or more groups. When observational data are used for this purpose, three more sources of bias may arise: confounding, survivorship bias, and selection due to preferential inclusion in surveillance datasets of those who are hospitalized and/or die. We illustrate these biases and caution against causal interpretation of differential CFR among those receiving different interventions in observational datasets. Again, we discuss ways to reduce these biases, particularly by estimating outcomes in smaller but more systematically defined cohorts ascertained before the onset of symptoms, such as those identified by forward contact tracing. Finally, we discuss the circumstances in which these biases may affect non-causal interpretation of risk factors for death among cases.


id: cord-268329-apl6n6jl
title: Will cases of leprosy reaction increase with COVID-19 infection?
author: Antunes, Douglas Eulálio
date: 2020-07-17
txt: ./txt/cord-268329-apl6n6jl.txt
cache: ./cache/cord-268329-apl6n6jl.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0008460
doi: 10.1371/journal.pntd.0008460
abstract: nan
summary:
  The coronavirus disease 2019 (COVID-19)-caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a betacoronavirus (betaCoV)-emerged for the first time as an outbreak of pneumonia in Wuhan, China, and it is now spreading to several countries around the world [1] . Some studies of SARS-CoV-2 infection have reported the presence of a cytokine storm syndrome and a subgroup of patients who progressed to severe forms of the disease, expressing a pro-inflammatory profile in plasma with IL-2, IL-7, TNF-α, and others as significant complications, such as occurs in T1R [10, 11] . In both reactions, we warn of the possible effect that COVID-19 infection may have on the number of cases of these immunological events because the presence of infection is an important risk factor for triggering leprosy reactions [8] . Another disturbing factor, which may contribute to the susceptibility of those affected by leprosy reactions, are the treatments implemented during these events that interfere with the inflammatory response of these patients.


id: cord-269004-hj03n13h
author: Krähling, Verena
date: 2010-08-24
url: https://doi.org/10.1371/journal.pntd.0000802
doi: 10.1371/journal.pntd.0000802
title:
  Establishment of Fruit Bat Cells (Rousettus aegyptiacus) as a Model System for the Investigation of Filoviral Infection

abstract:
  BACKGROUND: The fruit bat species Rousettus aegyptiacus was identified as a potential reservoir for the highly pathogenic filovirus Marburg virus. To establish a basis for a molecular understanding of the biology of filoviruses in the reservoir host, we have adapted a set of molecular tools for investigation of filovirus replication in a recently developed cell line, R06E, derived from the species Rousettus aegyptiacus. METHODOLOGY/PRINCIPAL FINDINGS: Upon infection with Ebola or Marburg viruses, R06E cells produced viral titers comparable to VeroE6 cells, as shown by TCID(50) analysis. Electron microscopic analysis of infected cells revealed morphological signs of filovirus infection as described for human- and monkey-derived cell lines. Using R06E cells, we detected an unusually high amount of intracellular viral proteins, which correlated with the accumulation of high numbers of filoviral nucleocapsids in the cytoplasm. We established protocols to produce Marburg infectious virus-like particles from R06E cells, which were then used to infect naïve target cells to investigate primary transcription. This was not possible with other cell lines previously tested. Moreover, we established protocols to reliably rescue recombinant Marburg viruses from R06E cells. CONCLUSION/SIGNIFICANCE: These data indicated that R06E cells are highly suitable to investigate the biology of filoviruses in cells derived from their presumed reservoir.


id: cord-272250-asuxx1ln
title: Rabies-Related Knowledge and Practices Among Persons At Risk of Bat Exposures in Thailand
author: Robertson, Kis
date: 2011-06-28
url: https://www.ncbi.nlm.nih.gov/pubmed/21738801/
doi: 10.1371/journal.pntd.0001054
abstract:
  BACKGROUND: Rabies is a fatal encephalitis caused by lyssaviruses. Evidence of lyssavirus circulation has recently emerged in Southeast Asian bats. A cross-sectional study was conducted in Thailand to assess rabies-related knowledge and practices among persons regularly exposed to bats and bat habitats. The objectives were to identify deficiencies in rabies awareness, describe the occurrence of bat exposures, and explore factors associated with transdermal bat exposures. METHODS: A survey was administered to a convenience sample of adult guano miners, bat hunters, game wardens, and residents/personnel at Buddhist temples where mass bat roosting occurs. The questionnaire elicited information on demographics, experience with bat exposures, and rabies knowledge. Participants were also asked to describe actions they would take in response to a bat bite as well as actions for a bite from a potentially rabid animal. Bivariate analysis was used to compare responses between groups and multivariable logistic regression was used to explore factors independently associated with being bitten or scratched by a bat. FINDINGS: Of 106 people interviewed, 11 (10%) identified bats as a potential source of rabies. A history of a bat bite or scratch was reported by 29 (27%), and 38 (36%) stated either that they would do nothing or that they did not know what they would do in response to a bat bite. Guano miners were less likely than other groups to indicate animal bites as a mechanism of rabies transmission (68% vs. 90%, p = 0.03) and were less likely to say they would respond appropriately to a bat bite or scratch (61% vs. 27%, p = 0.003). Guano mining, bat hunting, and being in a bat cave or roost area more than 5 times a year were associated with history of a bat bite or scratch. CONCLUSIONS: These findings indicate the need for educational outreach to raise awareness of bat rabies, promote exposure prevention, and ensure appropriate health-seeking behaviors for bat-inflicted wounds, particularly among at-risk groups in Thailand.


id: cord-276271-3nz3169p
author: Deborggraeve, Stijn
date: 2009-06-02
txt: ./txt/cord-276271-3nz3169p.txt
cache: ./cache/cord-276271-3nz3169p.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0000450
doi: 10.1371/journal.pntd.0000450
summary:
  cruzi OligoC-TesT: A Simplified and Standardized Polymerase Chain Reaction Format for Diagnosis of Chagas Disease The specificity and sensitivity of the assay were evaluated on blood samples from 60 Chagas non-endemic and 48 endemic control persons and on biological samples from 33 patients, 7 reservoir animals, and 14 vectors collected in Chile. We assessed the diagnostic accuracy of the assay on a broad spectrum of biological samples from Chagas non-endemic and endemic control persons, infected children, adults, reservoir animals and vectors. DNA from 25 different Trypanosoma rangeli isolates (Table 1) and from Leishmania donovani, Trypanosoma brucei gambiense, Mycobacterium tuberculosis, Schistosoma mansoni and Plasmodium falciparum was obtained from other research groups. cruzi OligoC-TesT, a simple and standardized dipstick format for detection of PCR amplified T. cruzi OligoC-TesT, a simple and standardized dipstick format for detection of PCR amplified T.

title:
  T. cruzi OligoC-TesT: A Simplified and Standardized Polymerase Chain Reaction Format for Diagnosis of Chagas Disease

abstract:
  BACKGROUND: PCR has evolved into one of the most promising tools for T. cruzi detection in the diagnosis and control of Chagas disease. However, general use of the technique is hampered by its complexity and the lack of standardization. METHODOLOGY: We here present the development and phase I evaluation of the T. cruzi OligoC-TesT, a simple and standardized dipstick format for detection of PCR amplified T. cruzi DNA. The specificity and sensitivity of the assay were evaluated on blood samples from 60 Chagas non-endemic and 48 endemic control persons and on biological samples from 33 patients, 7 reservoir animals, and 14 vectors collected in Chile. PRINCIPAL FINDINGS: The lower detection limits of the T. cruzi OligoC-TesT were 1 pg and 1 to 10 fg of DNA from T. cruzi lineage I and II, respectively. The test showed a specificity of 100% (95% confidence interval [CI]: 96.6%–100%) on the control samples and a sensitivity of 93.9% (95% CI: 80.4%–98.3%), 100% (95% CI: 64.6%–100%), and 100% (95% CI: 78.5%–100%) on the human, rodent, and vector samples, respectively. CONCLUSIONS: The T. cruzi OligoC-TesT showed high sensitivity and specificity on a diverse panel of biological samples. The new tool is an important step towards simplified and standardized molecular diagnosis of Chagas disease.


id: cord-276850-tnlyk0wz
author: Rodrigues, Anderson Messias
date: 2015-08-25
url: https://www.ncbi.nlm.nih.gov/pubmed/26305691/
doi: 10.1371/journal.pntd.0004016
title:
  Proteomics-Based Characterization of the Humoral Immune Response in Sporotrichosis: Toward Discovery of Potential Diagnostic and Vaccine Antigens

abstract:
  BACKGROUND: Sporothrix schenckii and associated species are agents of human and animal sporotrichosis that cause large sapronoses and zoonoses worldwide. Epidemiological surveillance has highlighted an overwhelming occurrence of the highly pathogenic fungus Sporothrix brasiliensis during feline outbreaks, leading to massive transmissions to humans. Early diagnosis of feline sporotrichosis by demonstrating the presence of a surrogate marker of infection can have a key role for selecting appropriate disease control measures and minimizing zoonotic transmission to humans. METHODOLOGY: We explored the presence and diversity of serum antibodies (IgG) specific against Sporothrix antigens in cats with sporotrichosis and evaluated the utility of these antibodies for serodiagnosis. Antigen profiling included protein extracts from the closest known relatives S. brasiliensis and S. schenckii. Enzyme-linked immunosorbent assays and immunoblotting enabled us to characterize the major antigens of feline sporotrichosis from sera from cats with sporotrichosis (n = 49), healthy cats (n = 19), and cats with other diseases (n = 20). PRINCIPAL FINDINGS: Enzyme-linked immunosorbent assay-based quantitation of anti-Sporothrix IgG exhibited high sensitivity and specificity in cats with sporotrichosis (area under the curve, 1.0; 95% confidence interval, 0.94–1; P<0.0001) versus controls. The two sets of Sporothrix antigens were remarkably cross-reactive, supporting the hypothesis that antigenic epitopes may be conserved among closely related agents. One-dimensional immunoblotting indicated that 3-carboxymuconate cyclase (a 60-kDa protein in S. brasiliensis and a 70-kDa protein in S. schenckii) is the immunodominant antigen in feline sporotrichosis. Two-dimensional immunoblotting revealed six IgG-reactive isoforms of gp60 in the S. brasiliensis proteome, similar to the humoral response found in human sporotrichosis. CONCLUSIONS: A convergent IgG-response in various hosts (mice, cats, and humans) has important implications for our understanding of the coevolution of Sporothrix and its warm-blooded hosts. We propose that 3-carboxymuconate cyclase has potential for the serological diagnosis of sporotrichosis and as target for the development of an effective multi-species vaccine against sporotrichosis in animals and humans.


id: cord-280030-neqycg6v
title: Clinical Features and Patient Management of Lujo Hemorrhagic Fever
author: Sewlall, Nivesh H.
date: 2014-11-13
url: https://www.ncbi.nlm.nih.gov/pubmed/25393244/
doi: 10.1371/journal.pntd.0003233
abstract:
  BACKGROUND: In 2008 a nosocomial outbreak of five cases of viral hemorrhagic fever due to a novel arenavirus, Lujo virus, occurred in Johannesburg, South Africa. Lujo virus is only the second pathogenic arenavirus, after Lassa virus, to be recognized in Africa and the first in over 40 years. Because of the remote, resource-poor, and often politically unstable regions where Lassa fever and other viral hemorrhagic fevers typically occur, there have been few opportunities to undertake in-depth study of their clinical manifestations, transmission dynamics, pathogenesis, or response to treatment options typically available in industrialized countries. METHODS AND FINDINGS: We describe the clinical features of five cases of Lujo hemorrhagic fever and summarize their clinical management, as well as providing additional epidemiologic detail regarding the 2008 outbreak. Illness typically began with the abrupt onset of fever, malaise, headache, and myalgias followed successively by sore throat, chest pain, gastrointestinal symptoms, rash, minor hemorrhage, subconjunctival injection, and neck and facial swelling over the first week of illness. No major hemorrhage was noted. Neurological signs were sometimes seen in the late stages. Shock and multi-organ system failure, often with evidence of disseminated intravascular coagulopathy, ensued in the second week, with death in four of the five cases. Distinctive treatment components of the one surviving patient included rapid commencement of the antiviral drug ribavirin and administration of HMG-CoA reductase inhibitors (statins), N-acetylcysteine, and recombinant factor VIIa. CONCLUSIONS: Lujo virus causes a clinical syndrome remarkably similar to Lassa fever. Considering the high case-fatality and significant logistical impediments to controlled treatment efficacy trials for viral hemorrhagic fever, it is both logical and ethical to explore the use of the various compounds used in the treatment of the surviving case reported here in future outbreaks. Clinical observations should be systematically recorded to facilitate objective evaluation of treatment efficacy. Due to the risk of secondary transmission, viral hemorrhagic fever precautions should be implemented for all cases of Lujo virus infection, with specialized precautions to protect against aerosols when performing enhanced-risk procedures such as endotracheal intubation.


id: cord-281456-3dlsbr7c
author: Al-alimi, Abdullah Ahmed
date: 2014-03-13
url: https://www.ncbi.nlm.nih.gov/pubmed/24625456/
doi: 10.1371/journal.pntd.0002711
title:
  Dengue Virus Type 2 (DENV2)-Induced Oxidative Responses in Monocytes from Glucose-6-Phosphate Dehydrogenase (G6PD)-Deficient and G6PD Normal Subjects

abstract:
  BACKGROUND: Dengue virus is endemic in peninsular Malaysia. The clinical manifestations vary depending on the incubation period of the virus as well as the immunity of the patients. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Malaysia where the incidence is 3.2%. It has been noted that some G6PD-deficient individuals suffer from more severe clinical presentation of dengue infection. In this study, we aim to investigate the oxidative responses of DENV2-infected monocytes from G6PD-deficient individuals. METHODOLOGY: Monocytes from G6PD-deficient individuals were infected with DENV2 and infection rate, levels of oxidative species, nitric oxide (NO), superoxide anions (O(2) (−)), and oxidative stress were determined and compared with normal controls. PRINCIPAL FINDINGS: Monocytes from G6PD-deficient individuals exhibited significantly higher infection rates compared to normal controls. In an effort to explain the reason for this enhanced susceptibility, we investigated the production of NO and O(2) (−) in the monocytes of individuals with G6PD deficiency compared with normal controls. We found that levels of NO and O(2) (−) were significantly lower in the DENV-infected monocytes from G6PD-deficient individuals compared with normal controls. Furthermore, the overall oxidative stress in DENV-infected monocytes from G6PD-deficient individuals was significantly higher when compared to normal controls. Correlation studies between DENV-infected cells and oxidative state of monocytes further confirmed these findings. CONCLUSIONS/SIGNIFICANCE: Altered redox state of DENV-infected monocytes from G6PD-deficient individuals appears to augment viral replication in these cells. DENV-infected G6PD-deficient individuals may contain higher viral titers, which may be significant in enhanced virus transmission. Furthermore, granulocyte dysfunction and higher viral loads in G6PD-deificient individuals may result in severe form of dengue infection.


id: cord-285772-4xt4anq5
author: Huang, Rui
date: 2020-05-08
url: https://www.ncbi.nlm.nih.gov/pubmed/32384078/
doi: 10.1371/journal.pntd.0008280
title:
  Clinical findings of patients with coronavirus disease 2019 in Jiangsu province, China: A retrospective, multi-center study

abstract:
  Limited data are available for clinical characteristics of patients with coronavirus disease 2019 (COVID-19) outside Wuhan. This study aimed to describe the clinical characteristics of COVID-19 and identify the risk factors for severe illness of COVID-19 in Jiangsu province, China. Clinical data of hospitalized COVID-19 patients were retrospectively collected in 8 hospitals from 8 cities of Jiangsu province, China. Clinical findings of COVID-19 patients were described and risk factors for severe illness of COVID-19 were analyzed. By Feb 10, 2020, 202 hospitalized patients with COVID-19 were enrolled. The median age of patients was 44.0 years (interquartile range, 33.0–54.0). 55 (27.2%) patients had comorbidities. At the onset of illness, the common symptoms were fever (156 [77.2%]) and cough (120 [59.4%]). 66 (32.7%) patients had lymphopenia. 193 (95.5%) patients had abnormal radiological findings. 11 (5.4%) patients were admitted to the intensive care unit and none of the patients died. 23 (11.4%) patients had severe illness. Severe illness of COVID-19 was independently associated with body mass index (BMI) ≥ 28 kg/m(2) (odds ratio [OR], 9.219; 95% confidence interval [CI], 2.731 to 31.126; P<0.001) and a known history of type 2 diabetes (OR, 4.326; 95% CI, 1.059 to 17.668; P = 0.041). In this case series in Jiangsu Province, COVID-19 patients had less severe symptoms and had better outcomes than the initial COVID-19 patients in Wuhan. The BMI ≥ 28 kg/m(2) and a known history of type 2 diabetes were independent risk factors of severe illness in patients with COVID-19.


id: cord-286255-ded5t1ai
author: Tomashek, Kay M.
date: 2017-09-13
txt: ./txt/cord-286255-ded5t1ai.txt
cache: ./cache/cord-286255-ded5t1ai.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28902845/
doi: 10.1371/journal.pntd.0005859
summary:
  Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV) 1–4, chikungunya virus (CHIKV), influenza A and B viruses (FLU A/B), 12 other respiratory viruses (ORV), enterovirus, Leptospira spp., and Burkholderia pseudomallei. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO) at presentation. By enrolling febrile patients at clinical presentation, we identified unbiased predictors of laboratory-positive dengue as compared to other common causes of AFI. Among 6,349 participants who presented early (<3 DPO) in the clinical course, leukopenia, thrombocytopenia, headache, eye pain, nausea, and dizziness were significant positive predictors of laboratory-positive dengue as compared to all other AFI cases across all age groups ( Table 5 ). Of note, 6% of participants !65 years old had dengue as a cause of AFI, a finding comparable to a Puerto Rico study in which 5% of 17,666 laboratory-positive dengue cases detected by surveillance were !65 years old [36] .

title:
  Clinical and epidemiologic characteristics of dengue and other etiologic agents among patients with acute febrile illness, Puerto Rico, 2012–2015

abstract:
  Identifying etiologies of acute febrile illnesses (AFI) is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico. Patients with fever ≤7 days were offered enrollment, and clinical data and specimens were collected at enrollment and upon discharge or follow-up. Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV) 1–4, chikungunya virus (CHIKV), influenza A and B viruses (FLU A/B), 12 other respiratory viruses (ORV), enterovirus, Leptospira spp., and Burkholderia pseudomallei. Clinical presentation and laboratory findings of participants infected with DENV were compared to those infected with CHIKV, FLU A/B, and ORV. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO) at presentation. Of 8,996 participants enrolled from May 7, 2012 through May 6, 2015, more than half (54.8%, 4,930) had a pathogen detected. Pathogens most frequently detected were CHIKV (1,635, 18.2%), FLU A/B (1,074, 11.9%), DENV 1–4 (970, 10.8%), and ORV (904, 10.3%). Participants with DENV infection presented later and a higher proportion were hospitalized than those with other diagnoses (46.7% versus 27.3% with ORV, 18.8% with FLU A/B, and 11.2% with CHIKV). Predictors of dengue in participants presenting <3 DPO included leukopenia, thrombocytopenia, headache, eye pain, nausea, and dizziness, while negative predictors were irritability and rhinorrhea. Predictors of dengue in participants presenting 3–5 DPO were leukopenia, thrombocytopenia, facial/neck erythema, nausea, eye pain, signs of poor circulation, and diarrhea; presence of rhinorrhea, cough, and red conjunctiva predicted non-dengue AFI. By enrolling febrile patients at clinical presentation, we identified unbiased predictors of laboratory-positive dengue as compared to other common causes of AFI. These findings can be used to assist in early identification of dengue patients, as well as direct anticipatory guidance and timely initiation of correct clinical management.


id: cord-287582-ya81rc2n
author: Viennet, Elvina
date: 2016-09-19
txt: ./txt/cord-287582-ya81rc2n.txt
cache: ./cache/cord-287582-ya81rc2n.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/27643596/
doi: 10.1371/journal.pntd.0004943
summary:
  We identified important epidemiological and environmental issues including the increase of local transmission despite control efforts, population growth, difficulty locating larval sites, and increased human mobility from neighboring endemic countries. A robust assessment of the economic burden helps to i) identify information gaps, research needs, and refinements to the national statistical reporting systems; ii) argue that policies on dengue control and prevention should be given a high priority on the public health policy agenda; and iii) provide a baseline measure to determine the cost effectiveness of dengue policies and programs [104] . The countries and states presented in this review have in common i) a competent mosquito vector, ii) introduction of DENV by travelers, iii) increased local transmission of dengue coinciding with population growth and increased mobility, iv) recent budget cuts impacting public health services, and v) a largely nonimmune population.

title:
  Public Health Responses to and Challenges for the Control of Dengue Transmission in High-Income Countries: Four Case Studies

abstract:
  Dengue has a negative impact in low- and lower middle-income countries, but also affects upper middle- and high-income countries. Despite the efforts at controlling this disease, it is unclear why dengue remains an issue in affluent countries. A better understanding of dengue epidemiology and its burden, and those of chikungunya virus and Zika virus which share vectors with dengue, is required to prevent the emergence of these diseases in high-income countries in the future. The purpose of this review was to assess the relative burden of dengue in four high-income countries and to appraise the similarities and differences in dengue transmission. We searched PubMed, ISI Web of Science, and Google Scholar using specific keywords for articles published up to 05 May 2016. We found that outbreaks rarely occur where only Aedes albopictus is present. The main similarities between countries uncovered by our review are the proximity to dengue-endemic countries, the presence of a competent mosquito vector, a largely nonimmune population, and a lack of citizens’ engagement in control of mosquito breeding. We identified important epidemiological and environmental issues including the increase of local transmission despite control efforts, population growth, difficulty locating larval sites, and increased human mobility from neighboring endemic countries. Budget cuts in health and lack of practical vaccines contribute to an increased risk. To be successful, dengue-control programs for high-income countries must consider the epidemiology of dengue in other countries and use this information to minimize virus importation, improve the control of the cryptic larval habitat, and engage the community in reducing vector breeding. Finally, the presence of a communicable disease center is critical for managing and reducing future disease risks.


id: cord-288202-r3r2bc7v
author: Morel, Noelia
date: 2013-01-10
url: https://www.ncbi.nlm.nih.gov/pubmed/23326610/
doi: 10.1371/journal.pntd.0001967
title:
  A Monoclonal Antibody-Based Copro-ELISA Kit for Canine Echinococcosis to Support the PAHO Effort for Hydatid Disease Control in South America

abstract:
  Cystic echinococcosis is still a major concern in South America. While some regions show advances in the control of the disease, others have among the highest incidence in the world. To reverse this situation the Pan American Health Organization (PAHO) has launched a regional project on cystic echinococcosis control and surveillance. An early concern of the program was the lack of a standardized diagnostic tool to monitor infection in dogs, a key target of control programs. Under this premise, we have developed a new copro-ELISA test after extensive screening of a large panel of monoclonal antibodies (MAbs) and polyclonal sera, which performs with high standards of sensitivity (92.6%) and specificity (86.4%) as established by necropsy diagnosis of dogs. The key component of the test, MAbEg9 has a convenient IgG isotype and reacts with a periodate-resistant epitope found in high molecular weight components of the worm. Time-course analysis of experimentally infected dogs showed that even animals with a very low number of parasites could be detected as early as day 20 post infection. The test was formulated in a ready-to-use kit format with proven stability of each component for a minimum of 3 months at room temperature. This characteristic facilitates its standardized use and shipping to other laboratories, which was demonstrated by the identical results obtained by two different laboratories in Peru and our own laboratory when a large number of field samples were analyzed independently in a blind fashion.


id: cord-292157-hrm69640
author: Stull-Lane, Annica R.
date: 2020-10-02
txt: ./txt/cord-292157-hrm69640.txt
cache: ./cache/cord-292157-hrm69640.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0008737
doi: 10.1371/journal.pntd.0008737
summary:
  Typhimurium infection and antibiotic treatment failure, we assessed the potential of two consecutive doses of vitamin A in alleviating infection in male and female mice on a VAD or control diet. We found that subtherapeutic antibiotic treatment synergized with vitamin A treatment in infected VAD male mice, significantly decreasing systemic bacterial levels, mitigating weight loss and improving survival. Typhimurium systemic bacterial levels (CFU) were assessed for male (n = 5) and female (n = 5) mice on a standard diet 5 days post-infection for the following treatment groups: 0 mg/ml, 0.01 mg/ml, 0.05 mg/ml, and 0.10 mg/ml enrofloxacin delivered in the drinking water. Typhimurium D23580 at day 4 post-infection were assessed for male and female mice on either control or VAD diets with the following treatment groups: mocktreated, vitamin A only, enrofloxacin (0.05 mg/ml) only, and vitamin A and enrofloxacin cotreatment (Fig 5A) .

title:
  Vitamin A supplementation boosts control of antibiotic-resistant Salmonella infection in malnourished mice

abstract:
  Disseminated disease from non-typhoidal Salmonella enterica strains results in >20% mortality globally. Barriers to effective treatment include emerging multidrug resistance, antibiotic treatment failure, and risk factors such as malnutrition and related micronutrient deficiencies. Individuals in sub-Saharan Africa are disproportionately affected by non-typhoidal S. enterica bloodstream infections. To inform a clinical trial in people, we investigated vitamin A as a treatment in the context of antibiotic treatment failure in a mouse model of vitamin A deficiency. Vitamin A-deficient (VAD) mice exhibited higher systemic bacterial levels with a multidrug-resistant clinical isolate in comparison to mice on a control diet. Sex-specific differences in vitamin A deficiency and disseminated infection with S. enterica serotype Typhimurium (S. Typhimurium) were observed. VAD male mice had decreased weight gain compared to control male mice. Further, infected VAD male mice had significant weight loss and decreased survival during the course of infection. These differences were not apparent in female mice. In a model of disseminated S. Typhimurium infection and antibiotic treatment failure, we assessed the potential of two consecutive doses of vitamin A in alleviating infection in male and female mice on a VAD or control diet. We found that subtherapeutic antibiotic treatment synergized with vitamin A treatment in infected VAD male mice, significantly decreasing systemic bacterial levels, mitigating weight loss and improving survival. These results suggest that assessing vitamin A as a therapy during bacteremia in malnourished patients may lead to improved health outcomes in a subset of patients, especially in the context of antibiotic treatment failure.


id: cord-294798-ji3p0l4j
author: White, Sarah K.
date: 2018-05-31
txt: ./txt/cord-294798-ji3p0l4j.txt
cache: ./cache/cord-294798-ji3p0l4j.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0006505
doi: 10.1371/journal.pntd.0006505
summary:
  We have previously reported isolation of ZIKV [8] , DENV [9] , Human coronavirus NL63 [10] , and Enterovirus D68 [11] from children in this school cohort; however, the cases/outbreaks in these prior publications did not include CHIKV, or cases within the May-August, 2014, time frame of the current study. Viral genomic RNA that was extracted from CHIKV, DENV1-4, and ZIKV strains that were obtained from the Biodefense and Emerging Infections Research Resource Repository (BEI Resources, Manassas, VA) were used as positive control materials for rtRT-PCR. The six ZIKV sequences obtained in June 2014 from the CHIKV co-infected patients were highly similar (99.9%) to each other and also cluster within a well-supported monophyletic clade, which, interestingly, includes a divergent strain isolated in 2016 from Guadaloupe (Figs 3B and S3B) .

title:
  Detection and phylogenetic characterization of arbovirus dual-infections among persons during a chikungunya fever outbreak, Haiti 2014

abstract:
  In the context of recent arbovirus epidemics, questions about the frequency of simultaneous infection of patients with different arbovirus species have been raised. In 2014, a major Chikungunya virus (CHIKV) epidemic impacted the Caribbean and South America. As part of ongoing screening of schoolchildren presenting with acute undifferentiated febrile illness in rural Haiti, we used RT-PCR to identify CHIKV infections in 82 of 100 children with this diagnosis during May—August 2014. Among these, eight were infected with a second arbovirus: six with Zika virus (ZIKV), one with Dengue virus serotype 2, and one with Mayaro virus (MAYV). These dual infections were only detected following culture of the specimen, suggesting low viral loads of the co-infecting species. Phylogenetic analyses indicated that the ZIKV and MAYV strains differ from those detected later in 2014 and 2015, respectively. Moreover, CHIKV and ZIKV strains from co-infected patients clustered monophyletically in their respective phylogeny, and clock calibration traced back the common ancestor of each clade to an overlapping timeframe of introduction of these arboviruses onto the island.


id: cord-296226-ugeupo3u
title: A greener vision for vector control: The example of the Singapore dengue control programme
author: Sim, Shuzhen
date: 2020-08-27
txt: ./txt/cord-296226-ugeupo3u.txt
cache: ./cache/cord-296226-ugeupo3u.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32853197/
doi: 10.1371/journal.pntd.0008428
summary:
  Aedes-borne diseases, in particular, including dengue, chikungunya, yellow fever, and Zika, are increasing at an alarming rate due to urbanisation, population movement, weak vector control programmes, and climate change. The environmental management put in place to implement this high standard of public cleanliness has greatly benefited Singapore''s efforts to tackle VBDs. Underscoring the view that Aedes-borne diseases are environmental diseases, dengue control in Singapore is led by the National Environment Agency (NEA), a statutory board of the Ministry of the Environment and Water Resources (MEWR). In view of the importance of infrastructure maintenance and design, environmental sanitation, people''s behaviours, and use of technologies on dengue prevention, the NEA collaborates closely with other government ministries (e.g., Health, National Development, Education, Finance), town councils (responsible for management and maintenance of the common property of public housing estates, including vector control), community associations, research and academic institutions, and the private sector (Fig 2) .

abstract:
  Vector-borne diseases are a major cause of morbidity and mortality worldwide. Aedes-borne diseases, in particular, including dengue, chikungunya, yellow fever, and Zika, are increasing at an alarming rate due to urbanisation, population movement, weak vector control programmes, and climate change. The World Health Organization calls for strengthening of vector control programmes in line with the Global Vector Control Response (GVCR) strategy, and many vector control programmes are transitioning to this new approach. The Singapore dengue control programme, situated within the country’s larger vision of a clean, green, and sustainable environment for the health and well-being of its citizens, provides an excellent example of the GVCR approach in action. Since establishing vector control operations in the 1960s, the Singapore dengue control programme succeeded in reducing the dengue force of infection 10-fold by the 1990s and has maintained it at low levels ever since. Key to this success is consideration of dengue as an environmental disease, with a strong focus on source reduction and other environmental management methods as the dominant vector control strategy. The programme collaborates closely with other government ministries, as well as town councils, communities, the private sector, and academic and research institutions. Community engagement programmes encourage source reduction, and house-to-house inspections accompanied by a strong legislative framework with monetary penalties help to support compliance. Strong vector and epidemiological surveillance means that routine control activities can be heightened to specifically target dengue clusters. Despite its success, the programme continues to innovate to tackle challenges such as climate change, low herd immunity, and manpower constraints. Initiatives include development of novel vector controls such as Wolbachia-infected males and spatiotemporal models for dengue risk assessment. Lessons learnt from the Singapore programme can be applied to other settings, even those less well-resourced than Singapore, for more effective vector control.


id: cord-303647-c4umbcvn
title: A New Approach for Monitoring Ebolavirus in Wild Great Apes
author: Reed, Patricia E.
date: 2014-09-18
url: https://www.ncbi.nlm.nih.gov/pubmed/25232832/
doi: 10.1371/journal.pntd.0003143
abstract:
  BACKGROUND: Central Africa is a “hotspot” for emerging infectious diseases (EIDs) of global and local importance, and a current outbreak of ebolavirus is affecting multiple countries simultaneously. Ebolavirus is suspected to have caused recent declines in resident great apes. While ebolavirus vaccines have been proposed as an intervention to protect apes, their effectiveness would be improved if we could diagnostically confirm Ebola virus disease (EVD) as the cause of die-offs, establish ebolavirus geographical distribution, identify immunologically naïve populations, and determine whether apes survive virus exposure. METHODOLOGY/PRINCIPAL FINDINGS: Here we report the first successful noninvasive detection of antibodies against Ebola virus (EBOV) from wild ape feces. Using this method, we have been able to identify gorillas with antibodies to EBOV with an overall prevalence rate reaching 10% on average, demonstrating that EBOV exposure or infection is not uniformly lethal in this species. Furthermore, evidence of antibodies was identified in gorillas thought previously to be unexposed to EBOV (protected from exposure by rivers as topological barriers of transmission). CONCLUSIONS/SIGNIFICANCE: Our new approach will contribute to a strategy to protect apes from future EBOV infections by early detection of increased incidence of exposure, by identifying immunologically naïve at-risk populations as potential targets for vaccination, and by providing a means to track vaccine efficacy if such intervention is deemed appropriate. Finally, since human EVD is linked to contact with infected wildlife carcasses, efforts aimed at identifying great ape outbreaks could have a profound impact on public health in local communities, where EBOV causes case-fatality rates of up to 88%.


id: cord-305890-mdwjrfzp
title: Chloroquine and Its Derivatives Exacerbate B19V-Associated Anemia by Promoting Viral Replication
author: Bönsch, Claudia
date: 2010-04-27
url: https://www.ncbi.nlm.nih.gov/pubmed/20436917/
doi: 10.1371/journal.pntd.0000669
abstract:
  BACKGROUND: An unexpectedly high seroprevalence and pathogenic potential of human parvovirus B19 (B19V) have been observed in certain malaria-endemic countries in parallel with local use of chloroquine (CQ) as first-line treatment for malaria. The aims of this study were to assess the effect of CQ and other common antimalarial drugs on B19V infection in vitro and the possible epidemiological consequences for children from Papua New Guinea (PNG). METHODOLOGY/PRINCIPAL FINDINGS: Viral RNA, DNA and proteins were analyzed in different cell types following infection with B19V in the presence of a range of antimalarial drugs. Relationships between B19V infection status, prior 4-aminoquinoline use and anemia were assessed in 200 PNG children <10 years of age participating in a case-control study of severe infections. In CQ-treated cells, the synthesis of viral RNA, DNA and proteins was significantly higher and occurred earlier than in control cells. CQ facilitates B19V infection by minimizing intracellular degradation of incoming particles. Only amodiaquine amongst other antimalarial drugs had a similar effect. B19V IgM seropositivity was more frequent in 111 children with severe anemia (hemoglobin <50 g/L) than in 89 healthy controls (15.3% vs 3.4%; P = 0.008). In children who were either B19V IgM or PCR positive, 4-aminoquinoline use was associated with a significantly lower admission hemoglobin concentration. CONCLUSIONS/SIGNIFICANCE: Our data strongly suggest that 4-aminoquinoline drugs and their metabolites exacerbate B19V-associated anemia by promoting B19V replication. Consideration should be given for choosing a non-4-aminoquinoline drug to partner artemisinin compounds in combination antimalarial therapy.


id: cord-306952-cpltrsa7
author: de Souza, Pedro Mansueto Melo
date: 2020-11-04
url: https://doi.org/10.1371/journal.pntd.0008830
doi: 10.1371/journal.pntd.0008830
abstract: nan
title:
  Validation of verbal autopsy and nasopharyngeal swab collection for the investigation of deaths at home during the COVID-19 pandemics in Brazil


id: cord-308343-crjjhpl1
title: Impact of confinement housing on study end-points in the calf model of cryptosporidiosis
author: Graef, Geneva
date: 2018-04-25
url: https://www.ncbi.nlm.nih.gov/pubmed/29694356/
doi: 10.1371/journal.pntd.0006295
abstract:
  BACKGROUND: Diarrhea is the second leading cause of death in children < 5 years globally and the parasite genus Cryptosporidium is a leading cause of that diarrhea. The global disease burden attributable to cryptosporidiosis is substantial and the only approved chemotherapeutic, nitazoxanide, has poor efficacy in HIV positive children. Chemotherapeutic development is dependent on the calf model of cryptosporidiosis, which is the best approximation of human disease. However, the model is not consistently applied across research studies. Data collection commonly occurs using two different methods: Complete Fecal Collection (CFC), which requires use of confinement housing, and Interval Collection (IC), which permits use of box stalls. CFC mimics human challenge model methodology but it is unknown if confinement housing impacts study end-points and if data gathered via this method is suitable for generalization to human populations. METHODS: Using a modified crossover study design we compared CFC and IC and evaluated the impact of housing on study end-points. At birth, calves were randomly assigned to confinement (n = 14) or box stall housing (n = 9), or were challenged with 5 x 10(7) C. parvum oocysts, and followed for 10 days. Study end-points included fecal oocyst shedding, severity of diarrhea, degree of dehydration, and plasma cortisol. FINDINGS: Calves in confinement had no significant differences in mean log oocysts enumerated per gram of fecal dry matter between CFC and IC samples (P = 0.6), nor were there diurnal variations in oocyst shedding (P = 0.1). Confinement housed calves shed significantly more oocysts (P = 0.05), had higher plasma cortisol (P = 0.001), and required more supportive care (P = 0.0009) than calves in box stalls. CONCLUSION: Housing method confounds study end-points in the calf model of cryptosporidiosis. Due to increased stress data collected from calves in confinement housing may not accurately estimate the efficacy of chemotherapeutics targeting C. parvum.


id: cord-309587-xc4jaw31
title: The Feasibility of Canine Rabies Elimination in Africa: Dispelling Doubts with Data
author: Lembo, Tiziana
date: 2010-02-23
url: https://doi.org/10.1371/journal.pntd.0000626
doi: 10.1371/journal.pntd.0000626
abstract:
  BACKGROUND: Canine rabies causes many thousands of human deaths every year in Africa, and continues to increase throughout much of the continent. METHODOLOGY/PRINCIPAL FINDINGS: This paper identifies four common reasons given for the lack of effective canine rabies control in Africa: (a) a low priority given for disease control as a result of lack of awareness of the rabies burden; (b) epidemiological constraints such as uncertainties about the required levels of vaccination coverage and the possibility of sustained cycles of infection in wildlife; (c) operational constraints including accessibility of dogs for vaccination and insufficient knowledge of dog population sizes for planning of vaccination campaigns; and (d) limited resources for implementation of rabies surveillance and control. We address each of these issues in turn, presenting data from field studies and modelling approaches used in Tanzania, including burden of disease evaluations, detailed epidemiological studies, operational data from vaccination campaigns in different demographic and ecological settings, and economic analyses of the cost-effectiveness of dog vaccination for human rabies prevention. CONCLUSIONS/SIGNIFICANCE: We conclude that there are no insurmountable problems to canine rabies control in most of Africa; that elimination of canine rabies is epidemiologically and practically feasible through mass vaccination of domestic dogs; and that domestic dog vaccination provides a cost-effective approach to the prevention and elimination of human rabies deaths.


id: cord-312223-qgwzgazd
author: Shafagati, Nazly
date: 2013-07-04
url: https://www.ncbi.nlm.nih.gov/pubmed/23861988/
doi: 10.1371/journal.pntd.0002296
title:
  The Use of NanoTrap Particles as a Sample Enrichment Method to Enhance the Detection of Rift Valley Fever Virus

abstract:
  BACKGROUND: Rift Valley Fever Virus (RVFV) is a zoonotic virus that is not only an emerging pathogen but is also considered a biodefense pathogen due to the threat it may cause to public health and national security. The current state of diagnosis has led to misdiagnosis early on in infection. Here we describe the use of a novel sample preparation technology, NanoTrap particles, to enhance the detection of RVFV. Previous studies demonstrated that NanoTrap particles lead to both 100 percent capture of protein analytes as well as an improvement of more than 100-fold in sensitivity compared to existing methods. Here we extend these findings by demonstrating the capture and enrichment of viruses. RESULTS: Screening of NanoTrap particles indicated that one particle, NT53, was the most efficient at RVFV capture as demonstrated by both qRT-PCR and plaque assays. Importantly, NT53 capture of RVFV resulted in greater than 100-fold enrichment from low viral titers when other diagnostics assays may produce false negatives. NT53 was also capable of capturing and enhancing RVFV detection from serum samples. RVFV that was inactivated through either detergent or heat treatment was still found bound to NT53, indicating the ability to use NanoTrap particles for viral capture prior to transport to a BSL-2 environment. Furthermore, both NP-40-lysed virus and purified RVFV RNA were bound by NT53. Importantly, NT53 protected viral RNA from RNase A degradation, which was not observed with other commercially available beads. Incubation of RVFV samples with NT53 also resulted in increased viral stability as demonstrated through preservation of infectivity at elevated temperatures. Finally, NanoTrap particles were capable of capturing VEEV and HIV, demonstrating the broad applicability of NanoTrap particles for viral diagnostics. CONCLUSION: This study demonstrates NanoTrap particles are capable of capturing, enriching, and protecting RVFV virions. Furthermore, the use of NanoTrap particles can be extended to a variety of viruses, including VEEV and HIV.


id: cord-322943-lvdl7puw
author: Lardon, Zélie
date: 2010-06-22
url: https://www.ncbi.nlm.nih.gov/pubmed/20582307/
doi: 10.1371/journal.pntd.0000723
title:
  Imported Episodic Rabies Increases Patient Demand for and Physician Delivery of Antirabies Prophylaxis

abstract:
  BACKGROUND: Imported cases threaten rabies reemergence in rabies-free areas. During 2000–2005, five dog and one human rabies cases were imported into France, a rabies-free country since 2001. The Summer 2004 event led to unprecedented media warnings by the French Public Health Director. We investigated medical practice evolution following the official elimination of rabies in 2001; impact of subsequent episodic rabies importations and national newspaper coverage on demand for and delivery of antirabies prophylaxis; regular transmission of epidemiological developments within the French Antirabies Medical Center (ARMC) network; and ARMC discussions on indications of rabies post-exposure prophylaxis (RPEP). METHODOLOGY/PRINCIPAL FINDINGS: Annual data collected by the National Reference Center for Rabies NRCR (1989–2006) and the exhaustive database (2000–2005) of 56 ARMC were analyzed. Weekly numbers of patients consulting at ARMC and their RPEP- and antirabies-immunoglobulin (ARIG) prescription rates were determined. Autoregressive integrated moving-average modeling and regression with autocorrelated errors were applied to examine how 2000–2005 episodic rabies events and their related national newspaper coverage affected demand for and delivery of RPEP. A slight, continuous decline of rabies-dedicated public health facility attendance was observed from 2000 to 2004. Then, during the Summer 2004 event, patient consultations and RPEP and ARIG prescriptions increased by 84%, 19.7% and 43.4%, respectively. Moreover, elevated medical resource use persisted in 2005, despite communication efforts, without any secondary human or animal case. CONCLUSIONS: Our findings demonstrated appropriate responsiveness to reemerging rabies cases and effective newspaper reporting, as no secondary case occurred. However, the ensuing demand on medical resources had immediate and long-lasting effects on rabies-related public health resources and expenses. Henceforth, when facing such an event, decision-makers must anticipate the broad impact of their media communications to counter the emerging risk on maintaining an optimal public health organization and implement a post-crisis communication strategy.


id: cord-332473-ec8lu2a3
title: Zika virus inhibits eIF2α-dependent stress granule assembly
author: Amorim, Raquel
date: 2017-07-17
url: https://www.ncbi.nlm.nih.gov/pubmed/28715409/
doi: 10.1371/journal.pntd.0005775
abstract:
  Zika virus (ZIKV), a member of the Flaviviridae family, is the most recent emerging arbovirus with pandemic potential. During infection, viruses trigger the host cell stress response, leading to changes in RNA translation and the assembly of large aggregates of stalled translation preinitiation complexes, termed stress granules (SGs). Several reports demonstrate that flaviviruses modulate the assembly of stress granules (SG). As an emerging pathogen, little is known however about how ZIKV modulates the host cell stress response. In this work, we investigate how ZIKV modulates SG assembly. We demonstrate that ZIKV negatively impacts SG assembly under oxidative stress conditions induced by sodium arsenite (Ars), a treatment that leads to the phosphorylation of eIF2α. By contrast, no measurable difference in SG assembly was observed between mock and ZIKV-infected cells treated with sodium selenite (Se) or Pateamine A (PatA), compounds that trigger eIF2α-independent SG assembly. Interestingly, ZIKV infection markedly impaired the phosphorylation of eIF2α triggered in Ars-treated infected cells, and the abrogation of SG assembly in ZIKV-infected cells is, at least in part, dependent on eIF2α dephosphorylation. These data demonstrate that ZIKV elicits mechanisms to counteract host anti-viral stress responses to promote a cellular environment propitious for viral replication.


id: cord-340939-ikomc19t
author: van Doremalen, Neeltje
date: 2019-06-06
url: https://www.ncbi.nlm.nih.gov/pubmed/31170144/
doi: 10.1371/journal.pntd.0007462
title:
  A single-dose ChAdOx1-vectored vaccine provides complete protection against Nipah Bangladesh and Malaysia in Syrian golden hamsters

abstract:
  Nipah virus (NiV) is a highly pathogenic re-emerging virus that causes outbreaks in South East Asia. Currently, no approved and licensed vaccine or antivirals exist. Here, we investigated the efficacy of ChAdOx1 NiV(B), a simian adenovirus-based vaccine encoding NiV glycoprotein (G) Bangladesh, in Syrian hamsters. Prime-only as well as prime-boost vaccination resulted in uniform protection against a lethal challenge with NiV Bangladesh: all animals survived challenge and we were unable to find infectious virus either in oral swabs, lung or brain tissue. Furthermore, no pathological lung damage was observed. A single-dose of ChAdOx1 NiV(B) also prevented disease and lethality from heterologous challenge with NiV Malaysia. While we were unable to detect infectious virus in swabs or tissue of animals challenged with the heterologous strain, a very limited amount of viral RNA could be found in lung tissue by in situ hybridization. A single dose of ChAdOx1 NiV(B) also provided partial protection against Hendra virus and passive transfer of antibodies elicited by ChAdOx1 NiV(B) vaccination partially protected Syrian hamsters against NiV Bangladesh. From these data, we conclude that ChAdOx1 NiV(B) is a suitable candidate for further NiV vaccine pre-clinical development.


id: cord-345315-y3bdjnhg
author: Dai, Yaoyao
date: 2020-10-01
txt: ./txt/cord-345315-y3bdjnhg.txt
cache: ./cache/cord-345315-y3bdjnhg.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0008758
doi: 10.1371/journal.pntd.0008758
summary:
  We performed a comparative study to determine the feasibility of the early detection of the COVID-19 outbreak in China based on influenza surveillance data and the internet-based Baidu search index to evaluate the timelines of the alert signals compared with the traditional case reporting and response systems. The findings from this study suggest that monitoring abnormal surges of ILI and identifying peaks of online searches of key terms can provide early signals of novel disease outbreaks. In this study, we performed a comparative study to discuss the early warning capability, timelines, and validity of alert signals for the first wave of the COVID-19 outbreak in China based on the surveillance data of influenza-like illness (ILI) and the Baidu Search Index (BSI) compared with the traditional case reporting system.

title:
  Identifying the outbreak signal of COVID-19 before the response of the traditional disease monitoring system

abstract:
  New coronavirus cases and related deaths are continuing to occur worldwide. Early identification of the emergence of novel outbreaks of infectious diseases is critical to the generation of timely responses. We performed a comparative study to determine the feasibility of the early detection of the COVID-19 outbreak in China based on influenza surveillance data and the internet-based Baidu search index to evaluate the timelines of the alert signals compared with the traditional case reporting and response systems. An abnormal increase in the number of influenza-like illnesses (ILI) occurred at least one month earlier than the clinical reports of pneumonia with unknown causes and the conventional monitoring system. The peak of the search volume was 20 days earlier than the issuance of the massive official warning about the epidemic. The findings from this study suggest that monitoring abnormal surges of ILI and identifying peaks of online searches of key terms can provide early signals of novel disease outbreaks. We emphasize the importance of broadening the potential of syndromic surveillance, internet searches, and social media data together with the traditional disease surveillance system to enhance early detection and understanding of emerging infectious diseases. SYNOPSIS: Early identification of the emergence of an outbreak of a novel infectious disease is critical to generating a timely response. The traditional monitoring system is adequate for detecting the outbreak of common diseases; however, it is insufficient for the discovery of novel infectious diseases. In this study, we used COVID-19 as an example to compare the delay time of different tools for identifying disease outbreaks. The results showed that both the abnormal spike in influenza-like illnesses and the peak of online searches of key terms could provide early signals. We emphasize the importance of testing these findings and discussing the broader potential to use syndromic surveillance, internet searches, and social media data together with traditional disease surveillance systems for early detection and understanding of novel emerging infectious diseases.


id: cord-345494-8lcdx719
author: Chao, Chien-Chung
date: 2015-07-10
txt: ./txt/cord-345494-8lcdx719.txt
cache: ./cache/cord-345494-8lcdx719.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pntd.0003884
doi: 10.1371/journal.pntd.0003884
summary:
  title: Development of Recombinase Polymerase Amplification Assays for Detection of Orientia tsutsugamushi or Rickettsia typhi Recombinase polymerase amplification (RPA) assays using a lateral flow test (RPA-nfo) and real-time fluorescent detection (RPA-exo) were developed targeting the 47-kDa gene of O. Almost all antigen/pathogen detection assays for rickettsial diseases are based on polymerase chain reaction (PCR [7, 8] ), quantitative real-time PCR (qPCR) or nested PCR targeting different genes, including 56 kDa [9] , 47kDa [10] , groEL [11] of O. The DNA was used as template for the 17-RPA assay to evaluate its performance and qPCR was used to quantitate the copy number of the 17 kDa gene. honei and R japonica were also evaluated to show that they were not detectable by 17-RPA-nfo unless 10 4 or more copies of DNA were present, same results were obtained using 17-RPA-exo.

title:
  Development of Recombinase Polymerase Amplification Assays for Detection of Orientia tsutsugamushi or Rickettsia typhi

abstract:
  Sensitive, specific and rapid diagnostic tests for the detection of Orientia tsutsugamushi (O. tsutsugamushi) and Rickettsia typhi (R. typhi), the causative agents of scrub typhus and murine typhus, respectively, are necessary to accurately and promptly diagnose patients and ensure that they receive proper treatment. Recombinase polymerase amplification (RPA) assays using a lateral flow test (RPA-nfo) and real-time fluorescent detection (RPA-exo) were developed targeting the 47-kDa gene of O. tsutsugamushi or 17 kDa gene of R. typhi. The RPA assay was capable of detecting O. tsutsugamushi or R. typhi at levels comparable to that of the quantitative PCR method. Both the RPA-nfo and RPA-exo methods performed similarly with regards to sensitivity when detecting the 17 kDa gene of R. typhi. On the contrary, RPA-exo performed better than RPA-nfo in detecting the 47 kDa gene of O. tsutsugamushi. The clinical performance of the O. tsutsugamushi RPA assay was evaluated using either human patient samples or infected mouse samples. Eight out of ten PCR confirmed positives were determined positive by RPA, and all PCR confirmed negative samples were negative by RPA. Similar results were obtained for R. typhi spiked patient sera. The assays were able to differentiate O. tsutsugamushi and R. typhi from other phylogenetically related bacteria as well as mouse and human DNA. Furthermore, the RPA-nfo reaction was completed in 20 minutes at 37(o)C followed by a 10 minute incubation at room temperature for development of an immunochromatographic strip. The RPA-exo reaction was completed in 20 minutes at 39(o)C. The implementation of a cross contamination proof cassette to detect the RPA-nfo fluorescent amplicons provided an alternative to regular lateral flow detection strips, which are more prone to cross contamination. The RPA assays provide a highly time-efficient, sensitive and specific alternative to other methods for diagnosing scrub typhus or murine typhus.


id: cord-350533-fp1ctpax
author: Tchesnokov, Egor P.
date: 2020-06-04
url: https://www.ncbi.nlm.nih.gov/pubmed/32497085/
doi: 10.1371/journal.pntd.0008283
title:
  Independent inhibition of the polymerase and deubiquitinase activities of the Crimean-Congo Hemorrhagic Fever Virus full-length L-protein

abstract:
  BACKGROUND: The Crimean-Congo hemorrhagic fever virus (CCHFV) is a segmented negative-sense RNA virus that can cause severe human disease. The World Health Organization (WHO) has listed CCHFVas a priority pathogen with an urgent need for enhanced research activities to develop effective countermeasures. Here we adopted a biochemical approach that targets the viral RNA-dependent RNA polymerase (RdRp). The CCHFV RdRp activity is part of a multifunctional L protein that is unusually large with a molecular weight of ~450 kDa. The CCHFV L-protein also contains an ovarian tumor (OTU) domain that exhibits deubiquitinating (DUB) activity, which was shown to interfere with innate immune responses and viral replication. We report on the expression, characterization and inhibition of the CCHFV full-length L-protein and studied both RNA synthesis and DUB activity. METHODOLOGY/PRINCIPLE FINDINGS: Recombinant full-length CCHFV L protein was expressed in insect cells and purified to near homogeneity using affinity chromatography. RdRp activity was monitored with model primer/templates during elongation in the presence of divalent metal ions. We observed a 14-mer full length RNA product as well as the expected shorter products when omitting certain nucleotides from the reaction mixture. The D2517N mutation of the putative active site rendered the enzyme inactive. Inhibition of RNA synthesis was studies with the broad-spectrum antivirals ribavirin and favipiravir that mimic nucleotide substrates. The triphosphate form of these compounds act like ATP or GTP; however, incorporation of ATP or GTP is markedly favored over the inhibitors. We also studied the effects of bona fide nucleotide analogues 2’-deoxy-2’-fluoro-CTP (FdC) and 2’-deoxy-2’-amino-CTP and demonstrate increased inhibitory effects due to higher rates of incorporation. We further show that the CCHFV L full-length protein and the isolated OTU domain cleave Lys48- and Lys63-linked polyubiqutin chains. Moreover, the ubiquitin analogue CC.4 inhibits the CCHFV-associated DUB activity of the full-length L protein and the isolated DUB domain to a similar extent. Inhibition of DUB activity does not affect elongation of RNA synthesis, and inhibition of RNA synthesis does not affect DUB activity. Both domains are functionally independent under these conditions. CONCLUSIONS/SIGNIFICANCE: The requirements for high biosafety measures hamper drug discovery and development efforts with infectious CCHFV. The availability of full-length CCHFV L-protein provides an important tool in this regard. High-throughput screening (HTS) campaigns are now feasible. The same enzyme preparations can be employed to identify novel polymerase and DUB inhibitors.


id: cord-352178-irjhmxsg
author: Saxton-Shaw, Kali D.
date: 2013-01-24
txt: ./txt/cord-352178-irjhmxsg.txt
cache: ./cache/cord-352178-irjhmxsg.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/23359824/
doi: 10.1371/journal.pntd.0001931
summary:
  Fifteen distinct chimeric viruses were constructed to evaluate both structural and non-structural regions of the genome and infection patterns were determined through artificial infectious feeds in An. gambiae with each of these chimeras. When ONNV non-structural protein 3 (nsP3) replaced nsP3 from CHIKV virus in one of the chimeric viruses, infection rates in An. gambiae went from 0% to 63.5%. Our study analyzed both structural and non-structural regions of the ONNV genome using chimeric viruses and artificially infected Anopheles gambiae mosquitoes. When ONNV non-structural protein 3 (nsP3) replaced nsP3 from chikungunya virus in one of the chimeric viruses, infection rates in An. gambiae went from 0% to 63.5%. Six additional non-structural chimeric viruses were also constructed using a novel type II restriction enzyme cloning strategy to examine the broader genome with respect to ONNV''s unique vector specificity for An. gambiae mosquitoes (Figure 2) .

title:
  O''nyong nyong Virus Molecular Determinants of Unique Vector Specificity Reside in Non-Structural Protein 3

abstract:
  O'nyong nyong virus (ONNV) and Chikungunya virus (CHIKV) are two closely related alphaviruses with very different infection patterns in the mosquito, Anopheles gambiae. ONNV is the only alphavirus transmitted by anopheline mosquitoes, but specific molecular determinants of infection of this unique vector specificity remain unidentified. Fifteen distinct chimeric viruses were constructed to evaluate both structural and non-structural regions of the genome and infection patterns were determined through artificial infectious feeds in An. gambiae with each of these chimeras. Only one region, non-structural protein 3 (nsP3), was sufficient to up-regulate infection to rates similar to those seen with parental ONNV. When ONNV non-structural protein 3 (nsP3) replaced nsP3 from CHIKV virus in one of the chimeric viruses, infection rates in An. gambiae went from 0% to 63.5%. No other single gene or viral region addition was able to restore infection rates. Thus, we have shown that a non-structural genome element involved in viral replication is a major element involved in ONNV's unique vector specificity.


id: cord-352771-s0hfsxzb
author: Barriga, Gonzalo P.
date: 2016-07-14
txt: ./txt/cord-352771-s0hfsxzb.txt
cache: ./cache/cord-352771-s0hfsxzb.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/27414047/
doi: 10.1371/journal.pntd.0004799
summary:
  Based on our previous homology model structure for Gc from Andes hantavirus (ANDV), here we predicted and generated recombinant DIII and stem peptides to test whether these fragments inhibit hantavirus membrane fusion and cell entry. The Gc fragments interfered in ANDV cell entry by preventing membrane hemifusion and pore formation, retaining Gc in a non-resistant homotrimer stage, as described for DIII and stem peptide inhibitors of class II fusion proteins. Once the predicted DIII and stem fragments were synthesized, purified, and characterized, we measured their inhibitory activity against ANDV during virus cell entry via the native, endosomal infection route. In addition to the DIII of ANDV, peptides derived from the stem region of ANDV also cross-inhibited the PUUV fusion activity, which further corroborates the presence of conserved residues among hantavirus Gc proteins that are involved in the likely binding of this peptide.

title:
  Inhibition of the Hantavirus Fusion Process by Predicted Domain III and Stem Peptides from Glycoprotein Gc

abstract:
  Hantaviruses can cause hantavirus pulmonary syndrome or hemorrhagic fever with renal syndrome in humans. To enter cells, hantaviruses fuse their envelope membrane with host cell membranes. Previously, we have shown that the Gc envelope glycoprotein is the viral fusion protein sharing characteristics with class II fusion proteins. The ectodomain of class II fusion proteins is composed of three domains connected by a stem region to a transmembrane anchor in the viral envelope. These fusion proteins can be inhibited through exogenous fusion protein fragments spanning domain III (DIII) and the stem region. Such fragments are thought to interact with the core of the fusion protein trimer during the transition from its pre-fusion to its post-fusion conformation. Based on our previous homology model structure for Gc from Andes hantavirus (ANDV), here we predicted and generated recombinant DIII and stem peptides to test whether these fragments inhibit hantavirus membrane fusion and cell entry. Recombinant ANDV DIII was soluble, presented disulfide bridges and beta-sheet secondary structure, supporting the in silico model. Using DIII and the C-terminal part of the stem region, the infection of cells by ANDV was blocked up to 60% when fusion of ANDV occurred within the endosomal route, and up to 95% when fusion occurred with the plasma membrane. Furthermore, the fragments impaired ANDV glycoprotein-mediated cell-cell fusion, and cross-inhibited the fusion mediated by the glycoproteins from Puumala virus (PUUV). The Gc fragments interfered in ANDV cell entry by preventing membrane hemifusion and pore formation, retaining Gc in a non-resistant homotrimer stage, as described for DIII and stem peptide inhibitors of class II fusion proteins. Collectively, our results demonstrate that hantavirus Gc shares not only structural, but also mechanistic similarity with class II viral fusion proteins, and will hopefully help in developing novel therapeutic strategies against hantaviruses.


id: cord-355469-ojop6i4k
author: Egawa, Kazutaka
date: 2017-12-14
url: https://www.ncbi.nlm.nih.gov/pubmed/29240753/
doi: 10.1371/journal.pntd.0006076
title:
  Virulence, pathology, and pathogenesis of Pteropine orthoreovirus (PRV) in BALB/c mice: Development of an animal infection model for PRV

abstract:
  BACKGROUND: Cases of acute respiratory tract infection caused by Pteropine orthoreovirus (PRV) of the genus Orthoreovirus (family: Reoviridae) have been reported in Southeast Asia, where it was isolated from humans and bats. It is possible that PRV-associated respiratory infections might be prevalent in Southeast Asia. The clinical course of PRV is not fully elucidated. METHODS: The virulence, pathology, and pathogenesis of two PRV strains, a human-borne PRV strain (isolated from a patient, who returned to Japan from Bali, Indonesia in 2007) and a bat-borne PRV (isolated from a bat [Eonycteris spelaea] in the Philippines in 2013) were investigated in BALB/c mice using virological, pathological, and immunological study methods. RESULTS: The intranasal inoculation of BALB/c mice with human-borne PRV caused respiratory infection. In addition, all mice with immunity induced by pre-inoculation with a non-lethal dose of PRV were completely protected against lethal PRV infection. Mice treated with antiserum with neutralizing antibody activity after inoculation with a lethal dose of PRV showed a reduced fatality rate. In this mouse model, bat-borne PRV caused respiratory infection similar to human-borne PRV. PRV caused lethal respiratory disease in an animal model of PRV infection, in which BALB/c mice were used. CONCLUSIONS: The BALB/c mouse model might help to accelerate research on the virulence of PRV and be useful for evaluating the efficacy of therapeutic agents and vaccines for the treatment and prevention of PRV infection. PRV was shown for the first time to be a causative virus of respiratory disease on the basis of Koch’s postulations by the additional demonstration that PRV caused respiratory disease in mice through their intranasal inoculation with PRV.


