Pathogenic Escherichia coli strains from dogs and cats: Detection of enterotoxigenic (ETEC), enteropathogenic (EPEC), verotoxigenic (VTEC), enterohaemorrhagic (EHEC) et necrotoxigenic (NTEC) strains | Les souches pathogenes d'Escherichia coli chez les chiens et les chats: Detection des souches enterotoxinogenes (ETEC), enteropathogenes (EPEC), verotoxinogenes (VTEC), enterohemorragiques (EHEC) et necrotoxinogenes (NTEC)

Seven hundred and ninety-eight Escherichia coli isolates from dogs and 113 from cats of fecal, intestinal, urinary or blood origin were studied by DNA colony hybridization with 23 gene probes for specific virulence factors and/or properties of enterotoxigenic (ETEC), enteropathogenic (EPEC), verotoxigenic (VTEC), enterohaemorrhagic (EHEC), necrotoxigenic (NTEC), diffusely adherent (DAEC), and enteroaggregative (EAggEC) strains. Three hundred and ten canine (39 per cent) and 69 feline (61 per cent) isolates tested positive with at least one gene probe. Genes homologous to those coding for the LT2a enterotoxin, for the SLT1 verocytotoxin and for the F6, AF/R1 and Agg adhesins were not detected. Isolates positive with the probes were grouped in ETEC, EPEC, VTEC, EHEC, NTEC, and other strains, which did not fit in any of the first five groups. The most represented groups were the NTEC and the "other strains" groups, "other strains" which were positive with probes specific for adhesins only. All NTEC isolates, but three canine (98 per cent), had the NTEC1 hybridization profile, i.e. they are potentiel producers of the Cytotoxic Necrotizing Factor type 1 (CNF1). Most NTEC1 isolates were also positive with gene probes for fimbrial adhesins of P family, of S family, and for both families. The group of isolates positive with probes for adhesins could be further subdivided: ETEC adhesins, EPEC adhesins, VTEC adhesins, and NTEC adhesins. EPEC isolates were present in the same proportions among canine and feline isolates: i.e. 5 per cent. Two pathotypes were predominant: EaeA+ and EaeA+BFP+. On the opposite, VTEC and EHEC isolates were very rare (less than 1 per cent): two canine EHEC (FaeA+SLT2+) and two feline VTEC (SLT2+) isolates. Canine ETEC isolates were present (28 isolates, i.e. 3.5 per cent) but feline ETEC isolates were almost absent: one isolate. The canine ETEC isolates belonged to three main pathotypes: STa+, STa+STb+, and STb+. Sixty percent of canine and 40 per cent of feline isolates were thus negative to the 23 probes used. They may be isolates belonging to other uninvestigated or still unknown pathotypes or non pathogenic E. coli. The problem of the animal species specificity must also be questioned, as several isolates belonged to pathotypes regularly detected in human beings or in other animal species