High prevalence of ciprofloxacin resistance in Escherichia coli isolated from chickens, humans and the environment: An emerging one health issue

Abstract

The emergence of antimicrobial resistance in commensal bacteria poses a serious public health burden worldwide. Commensals can disseminate the resistance genes to pathogenic bacteria causing life-threatening infections. This cross-sectional study was designed to investigate the antimicrobial resistance pattern and molecular mechanism(s) of ciprofloxacin resistance in commensal E. coli from three major one health components (humans, animals and the environment) in Bangladesh. Samples were randomly collected from broiler chickens, broiler farm environments and hospitalized human patients from the same geographical area. Isolation and identification of E. coli were performed following standard bacteriological techniques. Antimicrobial susceptibility testing (AST) was performed by disk diffusion and broth microdilution methods. Mutation at the quinolone-resistance determining region (QRDR) was analyzed by sequencing. Of 450 samples, a total of 287 (63.8%; 95% CI 59.2–68.1%) E. coli strains was isolated, where 240 (83.6%; 95% CI 78.9–87.5%) strains were phenotypically resistant to ciprofloxacin. The prevalence of ciprofloxacin-resistant E. coli in broiler chicken, broiler farm environments and hospitalized human patients are 77.6%, 88.8% and 89% respectively. In AST against nine antimicrobials, all the isolates were found to be multidrug-resistant (MDR). The minimum inhibitory concentration (MIC) of ciprofloxacin was ranged from 4 to >128mg/L. Point mutations were detected in several sites of QRDR, specifically at 83 and 87 amino acid positions in gyrA gene, and 56, 57, 78, 80 and 84 amino acid positions in parC gene. Mutations resulted in amino acid substitutions. Phylogenetic analysis of gyrA and parC gene sequences showed a close relationship between the strains isolated from different sources. This study demonstrates a high prevalence of ciprofloxacin resistance in commensal E. coli in humans, animals and environment interface and their genealogically similarity poses an alarming public health consequence.

Genomic characterisation of Escherichia coli isolated from poultry at retail through Sink Surveillance in Dhaka, Bangladesh reveals high levels of multi-drug resistance

“…Ninety percent of isolates were resistant to the HP-CIA ciprofloxacin, and this correlated with the presence of mutations in the quinolone resistance determining regions of gyrA and/or parC (isolates with MIC = > 4 mg/L) and with the presence of plasmid mediated quinolone resistance genes of the qnrS family (isolates with MIC 0.25 or 0.5 mg/L). High prevalence of ciprofloxacin resistance in E. coli from poultry and humans has been previously reported in Bangladesh ( Das et al, 2023 ; Ibrahim et al, 2023 ). The use in WGS in this study provided new insights by demonstrating that ciprofloxacin resistance is present in a very wide diversity of E. coli STs and lineages ( Figure 1 ), rather than confined to specific clades.…”