Characterization of Shiga toxin-producing Escherichia coli isolated from dairy cows in Argentina
Article first published online: 16 JUL 2010
© 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology
Letters in Applied Microbiology
Volume 51, Issue 4, pages 377–382, October 2010
How to Cite
Fernández, D., Irino, K., Sanz, M.E., Padola, N.L. and Parma, A.E. (2010), Characterization of Shiga toxin-producing Escherichia coli isolated from dairy cows in Argentina. Letters in Applied Microbiology, 51: 377–382. doi: 10.1111/j.1472-765X.2010.02904.x
- Issue published online: 14 SEP 2010
- Article first published online: 16 JUL 2010
- 2010/0465: received 22 March 2010, revised 5 July 2010 and accepted 7 July 2010
- dairy cows;
- E. coli O157:H7;
- Shiga toxin;
- virulence genes
Aims: To feno-genotypically characterize the Shiga toxin-producing Escherichia coli (STEC) population in Argentinean dairy cows.
Methods and 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.
Significance and Impact of the study: 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.