title: Virulence factors and antimicrobial susceptibility of Escherichia coli isolated from calves in Turkey.
abstract: Escherichia coli isolates from calves were investigated by multiplex PCR assays for the presence of genes encoding K99, F41, F17-related fimbriae, heat-stabile enterotoxin a (STa), intimin (eae) and Shiga toxins (stx1 and stx2). A total of 120 E. coli isolates, 75 isolated from diarrhoeic or septicemic calves and 45 from clinically healthy calves aged between 1 day and 2 months were tested. Each isolate was obtained from different calves in different herds. Among the isolates from diseased animals, 12 (16%) isolates from 1- to 7-day-old diarrhoeic calves were detected as enterotoxigenic E. coli which possessed K99, F41 and STa in combination; F17-related fimbriae genes were detected in 33 (44%) isolates and they were found in combination with K99 + F41 + STa in two isolates. Of 120 isolates, 16 carried eae, eight stx1 and five stx2 genes alone or in combination. None of the eae- or stx-positive strains was identified as O157:H7. However, results indicate that calves may be carrier of Shiga toxin-producing E. coli which have potential as a human pathogen. Antimicrobial susceptibility of 75 isolates from diseased calves was determined by agar disk diffusion method for 14 antimicrobial agents. In 77.3% of the isolates, multiresistance was detected. Higher resistance rates were detected for cephalothin (72%), tetracycline (69.3%), kanamycin (69.3%), ampicillin (65.3%), nalidixic acid (53.3%), trimethoprim-sulphamethoxazole (52%) and enrofloxacin (41.3%), respectively. No resistance was found for ceftiofur and cefoxitin.
authors.affiliation: Veterinary Control and Research Institute, Konya, Turkey. gulerleyla@hotmail.com
authors.forename: L
authors.initials: L
authors.lastname: Güler
authors.forename: K
authors.initials: K
authors.lastname: Gündüz
authors.forename: U
authors.initials: U
authors.lastname: Ok
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000662:veterinary*; D005819:Genetic Markers / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D022603:Shiga Toxins / Q000096:biosynthesis / Q000235:genetics; D014421:Turkey; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D005819:Genetic Markers; D022603:Shiga Toxins