Prevalence of plasmid-mediated quinolone resistance genes in extended-spectrum beta-lactamase producing Klebsiella pneumoniae isolates in northern Iran

Plasmid-mediated quinolone resistance (PMQR) in extended-spectrum β-lactamase (ESBL)-producing <i>Klebsiella pneumoniae</i> (<i>K. pneumoniae</i>) contributes to treatment failures, extended hospital stays, and increased mortality percentages. We aimed to determine the prevalence of PMQR genes in ESBL-producing <i>K. pneumoniae</i> isolates from clinical samples in Babol, North of Iran region. This is the first study in this region to investigate this specific association. A total of 95 <i>K. pneumoniae</i> isolates were obtained from hospitalized patients with various clinical infections during March 2022 to February 2023. Disk diffusion and Combination disk method were performed to identification of antimicrobial resistance profiles and ESBL-producing strains. The presence of ESBL and PMQR genes among <i>K. pneumoniae</i> isolates was assessed using polymerase chain reaction (PCR) method. Of the isolates, 68 (71.57 %) were considered as ESBL-producers. The <i>bla</i> _TEM, <i>bla</i> _SHV and <i>bla</i> _CTX-M genes were detected in 74.73 %, 57.89 %, and 41.05 % of <i>K. pneumoniae</i> isolates, respectively. Among the PMQR encoding genes, the highest and lowest frequency was associated to <i>qepA</i> (67.3 %) and <i>qnrA</i> (4.2 %), respectively. The frequency of <i>qnrA</i>, <i>qnrB, qnrS</i>, <i>acc</i> (<i>6'</i>)-<i>Ib</i>-<i>cr</i>, <i>qepA</i>, <i>oqxA</i>, and <i>oqxB</i> genes in 26 MDR-Kp isolates was 11.53 % (n; 3), 69.23 % (n; 18), 65.38 % (n; 17), 73.07 % (n; 19), 80.76 % (n; 21), 84.61 % (n; 22), and 76.92 % (n; 20), respectively. Our result revealed of the 68 ESBL gene-positive isolates, 60 (88.23 %) were positive for the PMQR gene. The co-occurrence of these genes within resistant isolates suggests potential linkage on mobile genetic elements such as plasmids. These findings highlight the significant burden of PMQR determinants in ESBL-producing <i>K. pneumoniae</i> and underscore the urgent need for effective control measures. Implementing robust antimicrobial stewardship programs and strengthening drug-resistance surveillance and control protocols are crucial to prevent the spread of resistant isolates.