The prevalence, virulence factors and antibiotic resistance of Escherichia coli O157 in feces of adult ruminants slaughtered in three provinces of Turkey

In the present study the prevalence, presence of Stx1, Stx2, EhlyA and eaeA virulence genes and antibiotic resistance of Escherichia coli O157 strains isolated from the feces of 417 adult ruminants slaughtered in three provinces of Turkey were investigated. A total of 16 (3.8%) E. coli O157 strains were isolated from 417 fecal samples. Among these strains 9 (3.3%), 4 (7.8%), 2 (2.4%) and 1 (7.1%) were obtained from 269 cattle, 51 water buffaloes, 83 sheep and 14 goats, respectively. All strains were screened for the presence of rfbO157, fliCH7, Stx1, Stx2, eaeA and EhlyA genes by PCR. The rfbO157 gene was determined in all strains, while 7 (43.8%) of 16 strains harbored fliCH7, Stx2, EhlyA and eaeA genes. eaeA gene was obtained from 11 (68.8%) strains, 4 (25.0%) of these were alone. The Stx1 gene was not determined in any of the 16 strains and 5 (31.2%) strains were also negative for fliCH7, Stx2, EhlyA and eaeA genes. High resistance rates were determined against ampicillin (68.7%), neomycin (68.7%), tetracycline (68.7%), trimethoprim/sulfamethoxazole (62.5%) and amoxicillin/clavulanic acid (56.2%) in 16 E. coli 157 strains isolated in this study. The present study investigated the presence of E. coli O157 serotype, its major virulence genes and antibiotic resistance in the strains isolated from the feces of different slaughtered ruminants, including cattle, water buffalo, sheep and goats for the first time in Turkey, and showed the water buffaloes, sheep and goats, like cattle, may be a potential reservoir of E. coli O157:H7 infections for humans.
Cilj ovoga istraživanja bio je utvrditi prevalenciju, prisutnost gena virulencije Stx1, Stx2, EhlyA i eaeA te otpornost na antibiotike sojeva E. coli O157 izoliranih iz izmeta 417 odraslih preživača zaklanih u tri turske provincije. Ukupno je izolirano 16 sojeva E. coli O157 (3,8 %). Od tih sojeva 9 sojeva (3,3 %) potjecalo je od 269 goveda, 4 soja (7,8 %) od 51 vodenog bivola, 2 soja (2,4 %) od 83 ovce i 1 soj (7,1 %) od 14 koza. Svi su sojevi analizirani metodom lančane reakcije polimeraze na prisutnost gena rfbO157, fliCH7, Stx1, Stx2, eaeA i EhlyA. Gen rfbO157 dokazan je u svim sojevima, dok su u 7 (43,8 %) od 16 sojeva utvrđeni geni fliCH7, Stx2, EhlyA i eaeA. Gen eaeA utvrđen je u 11 sojeva (68,8 %), a u 4 (25,0 %) od tih 11 bio je samo taj gen. Gen Stx1 nije pronađen ni u jednom od 16 sojeva, dok je 5 sojeva (31,2 %) bilo negativno za gene fliCH7, Stx2, EhlyA i eaeA. Utvrđena je visoka otpornost na ampicilin (68,7 %), neomicin (68,7 %), tetraciklin (68,7 %), trimetoprim/sulfametoksazol (62,5 %) i amoksicilin/klavulansku kiselinu (56,2 %) u 16 sojeva E. coli O157 izoliranih u ovom istraživanju. U ovom je istraživanju analizirana prisutnost serotipa E. coli O157, glavni geni virulencije i antibiotska otpornost u sojevima izoliranima iz izmeta nekoliko različitih vrsta preživača, uključujući goveda, vodene bivole, ovce i koze. Ovime je prvi put dokazano da navedene vrste životinja mogu biti potencijalni rezervoari infekcije bakterijom E. coli O157 za ljude u Turskoj.