key: cord-0009278-3l62b03x
authors: Reilly, Sheena; Trevor Willis, A
title: β→LACTAMASE-PRODUCING ANAEROBES
date: 1980-11-01
journal: Lancet
DOI: 10.1016/s0140-6736(80)92122-4
sha: 273a6d6d02514cf9a977de5432d02686d6a7ffa3
doc_id: 9278
cord_uid: 3l62b03x

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don-to-tendon) biceps and quadriceps femoris muscles from all cases were removed immediately and directly frozen in isopentane cooled with liquid nitrogen. Our histological and histochemical techniques are described elsewhere; also on frozen sections we did histochemical tests for calcium (glyoxal-bis-2-hydroxyanil and alizarin-red S). 1 In the control fetuses we did not find structural abnormalities in the muscle fibres (table); there were no opaque fibres except for scattered fibres at the edge of the sections. These fibres were the only ones that displayed calcium-positive staining in this group. However, in two at risk fetuses a significant percentage of dark opaque fibres (3' 5 -4 -3%) has been found. These fibres were intensely positive with both histochemical reactions for calcium (figure B). Further, some apparently normal fibres also displayed an increase of calcium content. Dark fibres were usually larger than normal and scattered among normal fibres; however, 5 these fibres had centrally located nuclei. Our findings accord with other observations from fetuses2,4,s at risk for Duchenne muscular dystrophy. 2 In this report, as well as in that by Emery and Burt,2 the percentage of calcium-positive fibres is almost the same as that of opaque fibres and both are significantly high only in fetuses at risk. Hypereosinophilic and calcium-positive fibres might represent artifacts resulting from hypercontraction induced by injury during muscle dissection. 1 However, we carefully took away the whole muscle and in our counting of positive elements we excluded fibres at the periphery of sections. Moreover, we did not find any difference between pregnancies terminated by hysterotomy and the one terminated by prostaglandin not mentioned above. Artifacts seem unlikely.

By analogy with similar findings in cases of Duchenne muscular dystrophy' ,7 we conclude that our data support the hypothesis that muscle fibre degeneration is present at an early stage of life in Duchenne muscular dystrophy, and this strongly encourages efforts directed at a prenatal test for affected fetuses. 4, p. 748) that (3-lactamase producing anxrobes may be responsible for the failure of penicillin therapy to eradicate Streptococcus pyogenes from children's throats. In a recent study of the anaerobic flora of the tonsils (to be published), we observed that the most prevalent anaerobic species (Bacteroides melaninogenicus) was frequently resistant on disc testing to 1 unit benzylpenicillin. The minimum inhibitory concentrations of penicillin and ampicillin were determined for 38 of these tonsillar isolates (table). Research into the drug histories of many of these children showed an alarming frequency of prescriptions for penicillin derivatives; this probably explains the high percentage of strains resistant to penicillin. Further studies are in progress to assess the penicillinase production by these oral strains.

In view of the heavy anaerobic flora to be found in the tonsillar crypts of children with recurrent tonsillitis, it follows that therapy directed at reducing the anaerobic bacterial component may be a pre-requisite for successful eradication of pyogenic streptococci with penicillin. We have shown that orally administered metronidazole achieves a statistically significant reduction in the anaerobic tonsillar flora. Controlled studies are in progress to determine the therapeutic efficacy of metronidazole in tonsillitis. Department SIR,-Workers in Britain,' India,2 and Australia3 have noted "coronavirus-like particles" in the stools of children with diarrhoea and also in presumably normal individuals. The particles carry a regular array of projections on their surface, as coronaviruses do, but the size and shape of the particles is highly pleomorphic. There are a number of distinct types of particle, the morphology of which will be reviewed elsewhere.4 We have investigated a case of diarrhoea in a 2Z year-old Asian child who had visited Pakistan four months previously. Campylobacter and cysts of Entamceba histolytica were isolated from the stool, and the child was treated with two courses of metronidazole. Urological investigations were negative. The diarrhoea remitted and the child was discharged without follow-up.

Examination of the differentially centrifuged ultracentrifugation pellet of the patient's stool by electrorimicroscopy with negative staining revealed large numbers of "coronavirus-1ike particles" type 34 ( fig. 1 ). The size and shape of the particles varied greatly; however, there was a regular array of projections around the periphery of the particles, approximately 23 nm in length. In close relationship to these particles were broad sheets of membraneous material, without distinctive morphology. An analogous pellet was fixed in buffered glutaraldehyde and osmic acid and embedded in Spurr resin, and stained sections were examined. The material of the pellet consisted essentially of two components. One was a number of large, almost empty envelopes 1.3-2-5 m long and 0-5-1-5 m wide, and whose wall consisted of a double layer of repeating subunits ( fig. 2) . The subunits had a repeating pattern of 15 -4 Fig. 2 -Partly empty envelope with wall composed of regularly repeating subunits, seen tangentially and cross-section.

Vesicular material is seen around periphery of envelope, and also some inside its cavity. (x70 000.)

Histochemical correlation in some neuromuscular disorders

Muscle histology and creatine kinase levels in the foetus in Duchenne muscular dystrophy

Antenatal diagnosis of Duchenne muscular dystrophy

Hyperreactive (hyaline, opaque, dark) muscle fibres in Duchenne dystrophy

Structural changes in the early stages of Duchenne muscular dystrophy

Coronavirus particles in faeces from patients with gastroenteritis

Pleomorphic virus-like particles in human faeces

Coronavirus-like particles in aboriginals and non-aboriginals in Western Australia

Coronaviruslike particles in human fæces