Phenotypic and genetic characterization of β-lactam resistance in Klebsiella from retail chicken meat in Mansoura, Egypt

Background and Objectives: This study was undertaken to characterize antimicrobial resistance phenotypes and genes encoding extended spectrum β-lactamases (ESBLs) in Klebsiella isolated from retail chicken meat in Mansoura, Egypt. Materials and Methods: Three hundred sixty chicken meat samples from 120 eviscerated chicken carcasses (3 cuts each) collected randomly from local retail chicken shops in Mansoura, Egypt during the period from April to June 2015, were assayed for the presence of Klebsiella by conventional bacteriological methods. Antimicrobial sensitivity for 12 antimicrobials using disk diffusion, ESBL phenotypic confirmation and PCR characterization of ESBL-encoding genes (blaTEM, blaCTX-M, blaOXA, blaSHV and blaCMY) were performed. Results: Klebsiella was identified from 22.2% (80/360) of the samples. Of the 12 antimicrobials tested, multidrug resistance (MDR; resistance to ≥3 of the antimicrobial classes) was observed in 96.25% (77/80) of the Klebsiella isolates. All the isolates were resistant to cefotaxime, ceftriaxone and aztreonam. ESBL-producers were phenotypically confirmed in 48.75% (39/80) of the isolates. The highest values (0.75 and 0.67) of multiple antibiotic resistance (MAR) significantly occurred in ESBL-producing isolates. PCR findings showed a significantly higher occurrence of β-lactamase encoding genes in ESBL (94.9%, 37/39) than non-ESBL producing isolates (4.9%, 2/41). The distribution of blaTEM, blaCTX-M and blaOXA among ESBL- producing isolates was 84.6%, 30.8% and 25.6%, respectively. Conclusion: Efficient monitoring and tracking of MDR, especially β-lactam resistance, in food sources is essential to predict the potential hazards for human infections.