Prevalence of bovine verotoxin-producing Escherichia coli in Argentina.
Faecal swabs obtained from 126 calves and 118 cows in Argentina were investigated for the presence of verotoxin-producing Escherichia coli (VTEC). VTEC strains were recovered from 10 (23%) of 43 calves with diarrhoea, from 24 (29%) of 83 healthy calves, from 40 (44%) of 91 healthy cows waiting at the slaughterhouse, and from 6 (22%) of 27 healthy grazing cattle. PCR showed that 21 (9%) of animals carried VT1+ strains, 49 (20%) VT2+ strains and 10 (4%) VT1+ VT2+ strains. VT1+ strains predominated among calves (16% versus 0.8%; p < 0.001). The presence of eae gene was significantly more frequent among VTEC strains isolated from calves (78%; 46/59) than from cows (2%; 1/65) (p < 0.001). Furthermore, eae gene was more prevalent in VT1+ strains (97%; 32/33) than in VT2+ strains (14%; 10/70) (p < 0.001) and in VT1+ VT2+ strains (24%; 5/21) (p < 0.001). Sorbitol negative high virulent strains serogroups O157 were not detected. This study indicates that cattle are a reservoir of VTEC strains, and that eae gene is associated with VT1+ strains that are predominating among young animals. Fortunately, only adult animals are taken to the slaughterhouse, among which VTEC strains negative for eae gene are predominating.
Sanz
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ME
Animal Health Department, Faculty of Veterinary, University of the Centre PBA, Tandil, Argentina.
Viñas
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MR
Parma
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AE
D000818:Animals; D001118:Argentina / Q000453:epidemiology; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002417:Cattle / Q000382:microbiology*; D002418:Cattle Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis*; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012016:Reference Values; D012703:Serotyping; D022622:Shiga Toxin 1; D013045:Species Specificity
D001427:Bacterial Toxins; D004269:DNA, Bacterial; D022622:Shiga Toxin 1