Antimicrobial susceptibility of Escherichia coli strains isolated from broiler chickens affected by colibacillosis in Setif

Abstract

In Setif East Algeria, one hundred and eighty Escherichia coli strains were isolated from broiler chickens with colibacillosis and were examined for susceptibility to antimicrobials of veterinary significance. In vitro antibiotic activities of 12 antibiotic substances against the isolates were determined by disc diffusion test. Antibiogram revealed a high level of resistance to enrofloxacin (72.2%), neomycin (75%), trimethoprim-sulfmethoxazole (82.2%), ampicillin (84.5%) and amoxicillin (87.8%), nalidixic acid (96.7%) and doxycycline (98.3%). There were moderate levels of resistance to chloramphenicol (45.6%) and streptomycin (66.1%). There were low levels of resistance to nitrofurantoin (18.9%), colistin (5.5) and gentamicin (5.5%). All strains were multi-drug resistant and more than half (56.1%) of the isolates were resistant to eight antibiotics. Thus, 60 antibiotic resistant patterns in E. coli strains were isolated, of which 13 were present significantly. These findings suggest the need for the introduction of surveillance programs in Algeria to monitor antimicrobial resistance in pathogenic bacteria that could be potentially transmitted to humans from animal food.