A CASE-CONTROL STUDY OF VEROCYTOTOXIGENIC ESCHERICHIA-COLI INFECTION IN CATS WITH DIARRHEA

The objectives of this study were to determine the prevalence of enter ic verocytotoxigenic E. coli (VTEC) infection in a population of cats in Ontario, and to determine whether an association exists between the presence of VTEC and feline diarrhea, Fecal samples from 179 cats, re presenting 113 cats with diarrhea and 66 cats with normal feces, were cultured for E. coli. The fecal cultures mere screened for verocytotox in activity with a Vero cell assay, Confirmation of the presence of ve rocytotoxin (VT) genes was done with polymerase chain reaction (PCR) a mplification; the frequency of occurrence of the genes for generic VT, VT1, and VT2 was determined, VTEC-positive samples mere defined as th ose that demonstrated cytotoxicity on the Vero cell assay and yielded E. coli possessing one or more of the VT genes, All VTEC-positive isol ates were serotyped, The overall prevalence of enteric VTEC infection in the cats was 12.3% (22/179), Statistical analysis of the case-contr ol data showed no significant association between VTEC infection and d iarrheal illness, The majority of the cats with VT-positive E. coli me re positive for the presence of the generic VT, rather than for VT1 or VT2; it is therefore possible that a novel verocytotoxin gene may exi st in E. coli isolated from cats, Eight VTEC strains were identified b y serotyping; 4 of these serotypes have previously been isolated from humans, and 2 from cattle, suggesting that cats may be capable of acti ng as reservoirs for human and bovine VTEC serotypes.