Background: Plasmid-borne quinolone resistance genes (qnr) have been a growing concern in human and veterinary medicine as they can often be found in combination with extended-spectrum beta-lactamases. The aim of this study was to investigate the occurrence of qnr determinants in ESBL-positive E. coli strain isolated from poultry in Algeria.
Methods: One E. coli isolate, showing reduced susceptibility to cefotaxime, recovered from fecal sample of parent broiler flock were investigated. Antimicrobial susceptibility was determined using Clinical and Laboratory Standards Institute methodology. The presence of a bla gene (blaCTX-M genotype groups 1, 2, 8 and 9, blaTEM and blaSHV), and then qnr gene (qnrA, qnrB, qnrS) was established by polymerase chain reaction (PCR) and sequencing. Escherichia coli was further characterized using molecular typing by multilocus sequence typing (MLST).
Results: In this study we describe, for the first time, the identification of an isolate of Escherichia coli from poultry which carried qnrB in combination with a blaSHV-12 gene. The E. coli was resistant to the following non-β-lactam antimicrobial agents: nalidixic acid, ciprofloxacin, levofloxacin, tetracycline, sulphonamides, trimethoprim, and trimethoprim-sulphamethoxazole. MLST indicated the presence of a sequence type ST132.
Conclusions: This study demonstrated that parent broiler feces may be a reservoir of E. coli co-harboring blaSHV-12 and qnrB genes. This may pose an animal and a public health risk, which requires future evaluation and control.