Antimicrobial resistance Escherichia coli isolated from calves

Abstract

A total of 160 Escherichia coli strains isolated from calves during one year period were investigated for verotoxigenicity, integron 1 and antibiotic resistance. Selected 30 verotoxigenic or integron 1 positive E. coli isolates were studied for antibiotic resistance genes, including the detection of extended-spectrum ß-lactamases and plasmid replicon profiling. Resistances to ampicillin, streptomycin and tetracycline were the most frequent detected and followed by resistance to neomycin, cotrimoxazol, chloramphenicol, florfenicol and enrofloxacin. Two ceftiofur resistant strains were positive for CTX-M 1 with plasmid of FIB incompatibility group. B/O and F1B plasmids were the most frequently carried replicons in VTEC. Majority of strains belonged to commensal phylogenetic group A. In conclusion, commensal Escherichia coli of calves are a reservoir of ESBL.