Incidence of sporadic infections due to enterotoxigenic Escherichia coli (ETEC) in the population of Hamburg, north Germany

Contribution to some phenotypical characteristics of Vibrio cincinnatiensis. Studies in one strain of a diarrhoeic human patient and in two isolates from aborted bovine fetuses

Until now, only a few strains of V. cincinnatiensis have been isolated. This study describes a further three isolates which originated in one case from a stool specimen of an immunocompromised elder patient suffering from enteritis and in two cases from the rennin stomachs of aborted bovine fetuses. These strains grew on TCBS, CIN, MacConkey and XLD plates. Their biochemical activities were dependent on NaCl concentration, in particular the formation of indole, lysine and ornithine decarboxylases, arginine dihydrolase, the reduction of nitrate and behaviour in the Voges-Proskauer test. Moreover, lysine decarboxylase and nitrate reductase were temperature-dependent. The knowledge of these hitherto unknown phenotypical characteristics may facilitate the diagnosis of the pathogen.

Frequency of enterovirulent Escherichia coli in diarrhoeal disease in The Netherlands

To assess the role of enterovirulent Escherichia coli in The Netherlands, faecal samples of 279 patients (108 children, 171 adults) with diarrhoea and 100 healthy controls were investigated in a prospective study. Enterovirulent Escherichia coli were identified by hybridization with five different non-radioactively labelled DNA probes specific for enteropathogenic Escherichia coli (EPEC), verocytotoxin producing Escherichia coli (VTEC) and enterotoxigenic Escherichia coli (ETEC). The rate of isolation of EPEC was 6.5% in patients with diarrhoea and 2.0% in asymptomatic persons. During the study period, no VTEC were isolated from patients with diarrhoea. ETEC were isolated from two persons, both of whom had experienced diarrhoea and had returned from travel in (sub)tropical areas. Our results suggest that diarrhoea is sporadically caused by ETEC among the indigenous population of The Netherlands, and is mainly associated with travel in endemic areas. Furthermore, the presence of EPEC probe-positive strains in the stool need not always be accompanied by symptoms of diarrhoea.

Enterotoxigenic and necrotizing Escherichia coli in human diarrhoea in Spain

Enterotoxigenic Escherichia coli (ETEC) strains of serotype 0153: K-:H45 CFA/I+ STa+ were associated with two outbreaks of neonatal diarrhoea that occurred in two different hospitals of Madrid, in one of which several children died. Two other outbreaks were associated with ETEC strains of serotypes 0159: K-:H21 (LT+) and 0159: K-:H4 (LT+ STa+) without CFA/I and CFA/II colonization factors. Necrotizing E. coli (NTEC) strains of serotype 06:K13, producing the cytotoxic necrotizing factor CNF1 and alpha-haemolysin, were also associated with two outbreaks of neonatal diarrhoea that occurred in a hospital in Madrid and in a hospital in Talavera de la Reina. The results of the characterization of some ETEC and NTEC strains isolated from sporadic cases of diarrhoea are also discussed.

Clinical and genetic aspects of Shiga-like toxin production in traditional enteropathogenic Escherichia coli

Cell culture tests, DNA colony blot hybridization and polymerase chain reaction were used to examine classical enteropathogenic Escherichia coli (EPEC) for the presence of Shiga-like toxin (SLT). Fifteen of 155 strains from West Germany, originally identified as EPEC on the basis of serotyping, were shown to harbor either SLT-I or SLT-II genes. All strains that hybridized with the 20-base oligonucleotide probes which are complementary to slt-IA or slt-IIA sequences derived from the genomic DNA of enterohemorrhagic E. coli O157:H7 strain 933 produced moderate or high levels of cytotoxin in Vero and HeLa cell assays. Four additional strains of low to moderate cytotoxicity did not hybridize with either probe. Five different serogroups producing SLTs were identified: O26, O55, O111, O119 and O128. All three SLT-positive E. coli O26:H11 and four of five E. coli O111:H- isolates hybridized with a 3.4 kilobase fragment (CVD 419 probe) derived from the 60-megadalton plasmid of EHEC O157:H7. Seven of the 15 SLT-gene positive strains were associated with bloody diarrhea, six isolates were from patients with hemolytic uremic syndrome (HUS). Based on their clinical, epidemiological, pathogenic and genetic features SLT-producing E. coli among classical EPEC mimic enterohemorrhagic E. coli O157:H7 and might be considered as EHEC.