antibiotic susceptibility and frequency of plasmid mediated quinolones resistant (qnr) genes amongst urine klebsiella pneumoniae isolates

Aims: klebsiella pneumoniae is a common cause of urinary tract infections (utis), especially in hospitals. quinolones work by blocking bacterial dna gyrase and topoisomerase iv, but the presence of qnr genes enables bacteria to survive despite these drugs. this study aimed to evaluate antibiotic susceptibility and the prevalence of plasmid-mediated quinolone resistance genes (qnra, qnrb, qnrs) in these isolates.instruments & methods: in this descriptive, cross-sectional study, 142 k. pneumoniae isolates were collected from uti patients at imam sajjad and kosar hospitals in yasuj and shiraz, iran, during 2020-2021. the disk diffusion method assessed resistance to various antibiotics, with a focus on quinolones. multiplex pcr was used to detect qnra, qnrb, and qnrs genes in quinolone-resistant isolates.findings: ciprofloxacin showed the highest resistance rate (60.6%). sensitivity was comparatively higher for sulfamethoxazole-trimethoprim (39.4%) and nalidixic acid (39.7%). the qnra, qnrb, and qnrs genes were found in 31.4%, 55.8%, and 10.5% of isolates, respectively. coexistence of qnra and qnrb occurred in 11 isolates, while qnrb and qnrs coexisted in 5 isolates. one isolate exhibited all three genes.conclusion: the study reveals a substantial prevalence of plasmid-mediated quinolone resistance genes in k. pneumoniae isolates from utis in these hospitals.