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 0157 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 gen are predominating.
Mots-clés Pascal : Escherichia coli, Enterobacteriaceae, Bactérie, Toxine, Bovin, Artiodactyla, Ungulata, Mammalia, Vertebrata, Epidémiologie, Prévalence, Animal, Argentine, Amérique du Sud, Amérique
Mots-clés Pascal anglais : Escherichia coli, Enterobacteriaceae, Bacteria, Toxin, Bovine, Artiodactyla, Ungulata, Mammalia, Vertebrata, Epidemiology, Prevalence, Animal, Argentina, South America, America
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0394799
Code Inist : 002B05B02F. Création : 25/01/1999.