Prevalence of Plasmid-Mediated Quinolone Resistance (PMQR) Determinants Among Extended Spectrum Beta-Lactamases (ESBL)-Producing Isolates of Escherichia coli and Klebsiella pneumoniae in Aleppo, Syria

Background: Recently, several plasmid-mediated quinolone resistance (PMQR) genes conferring low levels of quinolone resistance have been discovered. Objectives: The aim of the present study is to determine the prevalence of plasmid-mediated quinolone resistance genes in a collection of ESBL-producing isolates of E. coli and K. pneumonia in Aleppo, Syria. Materials and Methods: Here, to evaluate the prevalence of PMQR genes at Aleppo University hospitals in Syria, 123 extended spectrum beta-lactamases (ESBL)-producing isolates of Escherichia coli and Klebsiella pneumoniae from the hospitals were selected for screening based on ciprofloxacin resistance. Five PMQR genes [qnrA, qnrB, qnrS, aac (6')-Ib, and qepA] were screened by simplex PCR, and the aac (6')-Ib-positive PCR products were digested with BtsCI to detect the aac (6')-Ib-cr variant. Results: Of the 123 isolates, 103 (83.73%) had one of the five PMQR genes, including 83 (83.83%) of the 99 E. coli strains and 20 (86.95%) of the 23 K. pneumoniae strains. Conclusions: The most common qnr gene was qnrB, and none of the isolates carried qnrA or qepA. The aac (6')-Ib-cr variant was the most prevalent PMQR gene, and it was associated with the prevalence of ciprofloxacin resistance in our ESBL-producing isolates.