Interaction of Cryptosporidium parvum and Campylobacter jejuni in experimentally infected neonatal mice.

By the method of scanning electron microscopy (SEM), the inner mucosal surface of the ileum, ceacum and colon was studied in inbred BALB/c mice. Two-day-old mice were infected with either 10(6) oocysts of Cryptosporidium parvum and 10(8) CFU of porcine and human strains of the bacterium Campylobacter jejuni or with a combination of both enteropathogens. Pathological changes in infection with C. parvum were related to enterocytes and villous atrophy appeared. In infection with C. jejuni, pathological changes were related to goblet cells. In combined infections, pathological changes were similar to those in monoinfections and occurred simultaneously within the intestine. Synergistic interaction of C. parvum and C. jejuni manifested itself morphologically in a more intense colonization of the inner surface of the small and large intestine by C. jejuni, in a more intense infection of the caecum and colon by C. parvum, and in prolongation of severe, massive infection of the small and large intestine, and also a prolongation of the patent period.

Vero cytotoxin-producing strains of Escherichia coli in children with haemolytic uraemic syndrome and diarrhoea in Czechoslovakia.

The presence of verotoxin-producing strains of Escherichia coli (VTEC) was examined in six children with haemolytic uraemic syndrome and one child with haemorrhagic colitis. Stools were screened for strains of serogroup O157 on sorbitol-MacConkey agar for VTEC of other serogroups by serotyping. Verotoxin (VT) was tested on Vero cell monolayers: the antigenic variant of VT was assessed by neutralization experiments. Strains producing verotoxin 1 or verotoxin 2 or both were detected in the stools of all seven children. Three strains belonged to serogroup O157 (two of them to serotype O157:H7, one was non-motile) and another five belonged to serogroups O26 (two strains), O1, O5 and O18. The faeces of five children available for testing contained free VT. Production of VT was also examined retrospectively in 32 E. coli strains of serotype O26:H11 isolated from children with diarrhoea; eight (25%) of them produced moderate to high levels of verotoxin 1 despite several years storage in vitro. In conclusion, VTEC including strains of serogroup O157 seem to be an important cause of haemolytic uraemic syndrome, haemorrhagic colitis and diarrhoea in children in Czechoslovakia.

[Microbiological diagnosis of microorganisms tentatively designated as "SP organisms"]. / Príspevek k mikrobiologické diagnostice mikroorganismu provizorne oznacovaného jako "SP organismus".

The authors describe the biochemical characteristics of two strains described as "SP organism". This microorganism incertae sedis resembles from the biochemical aspect (oxidase+, mannite-, dextrose+ with gas) the species Pasteurella aerogenes; contrary to the latter it does not break down urea and differs also as regards the morphology of colonies, which on blood agar are coarser; it also has a higher content of G + C in DNA than Pasteurella. It is a pathogen of rodents. The authors describe two isolates, the first is obviously an incidental finding from the faeces of a 5-year-old girl who was symptom-free, the second is from the contents of an abscess of a nutria. For comparison also biochemical characteristics of known aerogenic pasteurellae and Pasteurella-like strains are given.

Rarely occurring Shigella serovars.

In addition to the predominant Shigella sonnei, also rarely occurring Shigella serovars have been found in Czechoslovakia: 4 serovars of subgroup A (S. dysenteriae 3, 4, 7 and 12) and 11 serovars of subgroup C (S. boydii 2, 3, 5, 7, 9 lactose-positive, 10, 13, 14 aerogenic, mannitol-negative, 15, 16 and the provisional serovar E 16553). First isolations of these serovars were mostly connected with cases imported from abroad. Some serovars were isolated repeatedly. Newly recognized serovars of S. flexneri (3b, 5a) as well as biochemically aberrant strains of subgroup B (S. flexneri), C (S. boydii) and D (S. sonnei) were isolated. Frequency and importance of some S. flexneri serovars have been changing in the course of time, e.g. S. flexneri 2b, that had evidently been frequent in central Europe 40 years ago, disappeared completely.

A new member of the family Enterobacteriaceae--Pragia fontium.

Twenty isolates of the new genus and species Pragia fontium producing H2S were biochemically characterized: they gave positive gluconate oxidation, utilized Simmons citrate and 14 of them hydrolysed esculin. One of them did not produce hydrogen sulfide. Their biochemical activity was low: they did not ferment lactose, adonitol, arabinose, cellobiose, dextrin, dulcitol, erythritol, inulin, maltose, mannitol, mannose, melezitose, melibiose, raffinose, rhamnose, sorbitol, sorbose, starch, sucrose or trehalose. The habitat of Pragia fontium is drinking water, with an exception: the last strain was found in a stool specimen of a healthy woman. The type culture is the first isolate No. 20125-HG 16. It is deposited in Prague (CNCTC) under the designation Eb 11/82.

First strains of the genus Kluyvera in Czechoslovakia.

Fourteen of 21 strains isolated from stools, urine specimens and the hospital environment were identified as Kluyvera. All of these 14 strains corresponded with the literary description of the genus Kluyvera and were identical with two reference strains except that one of them failed to utilize sodium acetate within 7 days. One strain (No. 23441) produced massive growth on Jordan's tartrate, which some Kluyvera do. Important in differentiating indole- and Simmons' citrate-negative Kluyvera strains from Escherichia vulneris (two other of our 21 strains) is negative ornithin decarboxylase and negative Christensen citrate in the latter. Three strains were identified as Citrobacter, where especially indole-positive and urease-negative strains may be reminiscent of Kluyvera. An aberrant strain, No. 25115, which alone failed to grow at 42 degrees C and by some characters differed from Kluyvera, E. vulneris and Enteric Group 10, was identified as E. coli.

Tween-esterase activity in Enterobacter sakazakii.

Seventy-one of 73 E. sakazakii strains isolated in Czechoslovakia produced Tween 80 esterase; its production was slower and less intensive than in Serratia, vibrios and aeromonads. The E. sakazakii strains did not produce lecithinase (yolk reaction was negative for 8 days). The following set of tests was recommended for verification of E. sakazakii identification: pigment (was produced by 100% of strains), Tween 80 esterase (was positive in 97.3%), mucate (negative in 100%) and sorbitol (negative in 100%).

A hydrogen sulphide producing Gram-negative rod from water.

The biochemical properties of a hydrogen sulphide-producing Gram-negative rod, provisionally designated HG group, were compared with those of the known H2S-producing and H2S-negative Enterobacteriaceae and related organisms. Sixty-four tests were used as a basis for numerical identification. All these tests demonstrated a distinctness of the HG group from other members of Enterobacteriaceae and related organisms. Results of numerical identification are discussed. According to the guanine-plus-cytosine molar content in DNA the bacterium could belong to the tribe Escherichiae of the family Enterobacteriaceae. Plasmids of different molecular size or linear fragments of DNA were found in 17 of 19 strains which indicates that the H2S production is not in correlation with the occurrence of a plasmid of definite size. So far, the only habitat of the HG group had been water, and it seems to be no rarity. Among 28 HG strains a single isolate HG16 was found which differs from HG group in biochemical properties. The distinctness of this single isolate has been confirmed also by numerical identification. Note: On the basis of DNA-DNA hybridization performed by Dr. P.A.D. Grimont and coworkers the HG group has been established as a new genus and a single species. The authors accordingly propose for the group the generic name Budvicia and the specific epithet aquatica.