key: cord-0005159-27q5n2ul authors: Magliani, W.; Somenzi, P.; Valcavi, P.; Tcherassen, M.; Fanti, F.; Moccia, G.; Chezzi, C. title: Epidemiological survey on bacterial, viral and parasitic agents in patients affected by acute enteritis date: 1985 journal: Eur J Epidemiol DOI: 10.1007/bf00141805 sha: b3002cbceada5e182ccbb463d6d68f81daef7a84 doc_id: 5159 cord_uid: 27q5n2ul During the period June 1983 – May 1984, faecal specimens from 797 patients with acute enteritis were examined for the presence of bacterial, viral and parasitic agents; 209 (26.2%) enteritic pathogens were identified, of whom 118 (35.4%) in 333 samples from the pediatrics wards. Bacterial agents were detected in 122 (15.3%), viruses in 63 (7.9%) and parasites in 25 (3.1%) of the 797 specimens. LT-producing E. coli, Salmonella and Rotavirus were the most frequent pathogens. Bacterial agents occurred most frequently in the summer and autumnal months, whereas viruses showed two peaks, the first one in summer due to cultivable agents, the second in winter to Rotavirus mainly. spp. were identified by s t a n d a r d m e t h o d s (4, 8) . In o r d e r to test the p r o d u c t i o n of heat-labile enterotoxin (LT), ten colonies with the typical a p p e a r a n c e of E. coli were selected f r o m each Mc Conkey agar p l a t e ; the p r o d u c t i o n of LT toxin was d e t e r m i n e d by the V ero cells assay (9, 10) . .127 Eur. J. Epidemiol. All enterotoxigenic isolates were finally identified by standard biochemical tests (4) . Each sample was also plated on blood agar with a supplemented selective m e d i u m for Camp y l o b a c t e r spp. (Butzler supplement; Oxoid Ltd.) (2) and incubated for 48 hours at 42°C in 5% oxygen and 10% carbon dioxide atmosphere. Isotates were G r a m stained and tested for motility, oxidase and catalas,e production, ability to growth in glici,ne ( 1% ), NaC1 Faecal suspensions (10%) in phosphate buffered saline ( p H 7.2) were centrifuged two times for 15 minutes at 2700xg to remove heavy sediments. The sup ernatants were tested by commercia] Rotazyme EIA (Abbott L a b o r a t o r i e s ) ; in addition, formvar-carbon-coated 400 mesh grids for electron microsco~py were p r e p a r e d by the lyphogel m e t h o d (11) and examined for a m i n i m u m of 20 minutes in a Philips EM 300 ,electron microscope. For the isolation and identification of viruses by cell cultures, 10% suspensions of stool specimens in Earle's balanced salt solution were centrifuged at 10,000 r p m for 1 hr at 4°C. The sup ernatant fluid was treated with penicillin (200 units/ml) and streptomycin (200 ~Lg/ml). Isolation was a t t e m p t e d in VERO, RD, HEp-2 and h u m a n foetal diploid cells using the methods previously described by Lennette and Schimdt (7) . (Table 1) . Bacterial agents were detected in 122 (15.3%3, viruses in 63 (7.9%) and parasites in 25 (3.1%) of the 797 specimens. Among bacterial :agents, Salmonella, S. aureus and LT-producing E. coli were the most frequent enteropathogens; the incidence of C. j e j u n i and Y. enterocolitica was found to be very low ( Table 2 ). Serogroup 09, biotype 2, lysotype X 3 was the unique isolated Y. enterocolitica strain. Rotavirus was the most frequently identified viral agent, mainly occurring in the samples f r o m pediatric wards (Table 3) ; Giardia lamblia and E n t e r o b i u s vermicularis were observed as the prevalent parasitic agents. (Table 4) . Associated agents were detected in 14 patients ( Pediatric Viral gas,troenteritis during eight years of study Campylobacter enteritis Human viral gastroenteritis Identification of Enterobacteriaceae Diarrhoea among infants and young children in Canada: a longitudinal study in three northern communities Influence of temperature and relative humidity on human rotavirus infection in Japan Diagnostic procedures for viral and rickettsial infections Manual of Clinical Microbiology Detection of heat-labile Escherichia coil enterotoxin using Vero cells in m~cTo-culture-Serotyping of producing strains Assay of Escherichia coil heat-labile enterotoMn with Veto cells Detection of virus particles by electron microscopy width polyacrilamide hydrogel This work was supported by Progetto Finalizzato Controllo delle Malattie da Infe~ione, grant No. 83.00638.52, from Consiglio Nazionale delle Ricerche (CNR), Roma, Italy.We wish to thank Giorgio Medici, Giorgio Martani and Maria Grazia Lombardi for their excellent te-chnicM assistance.