Characterization of Shiga toxin-producing Escherichia coli isolated from dairy cows in Argentina.
OBJECTIVE
To feno-genotypically characterize the Shiga toxin-producing Escherichia coli (STEC) population in Argentinean dairy cows.


RESULTS
From 540 STEC positive samples, 170 isolates were analyzed by multiplex PCR and serotyping. Of these, 11% carried stx1, 52% stx2 and 37% stx1/stx2. The ehxA, saa and eae were detected in 77%, 66% and 3%, respectively. Thirty-five per cent of strains harboured the profile stx1, stx2, saa, ehxA and 29% stx2, saa, ehxA. One hundred and fifty-six strains were associated with 29 different O serogroups, and 19 H antigens were distributed among 157 strains. STEC O113:H21, O130:H11 and O178:H19 were the most frequently found serotypes. The STEC O157:H7 were detected in low rate and corresponded to the stx2(+) , eae(+) , ehxA(+) virulence pattern.


CONCLUSIONS
We detected a diversity of STEC strains in dairy cattle from Argentina, most of them carrying genes linked to human disease.


CONCLUSIONS
The non-O157 STEC serotypes described in this study are associated worldwide with disease in humans and represent a risk for the public health. For this, any microbiological control in dairy farms should be targeted not only to the search of O157:H7 serotype.
Fernández
D
D
Laboratorio de Inmunoquímica y Biotecnología, FCV, UNCPBA, Pinto, Tandil, Argentina.
Irino
K
K
Sanz
M E
ME
Padola
N L
NL
Parma
A E
AE
D000818:Animals; D001118:Argentina; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D003612:Dairying; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012703:Serotyping; D022641:Shiga Toxin 2 / Q000235:genetics; D022603:Shiga Toxins / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
D029968:Escherichia coli Proteins; D022641:Shiga Toxin 2; D022603:Shiga Toxins; D037521:Virulence Factors