molecular characterization of plasmid-mediated quinolone resistance genes in clinical isolates of pseudomonas aeruginosa from al-muthanna province, iraq

Background and objectives: fluoroquinolones represent a class of antibiotics commonly used to manage pseudomonas aeruginosa infections. the appearance of fluoroquinolone resistance in p. aeruginosa represents a critical challenge to healthcare systems. materials and methods: between january and december 2024, 650 clinical specimens were collected from al-hussein teaching hospital and al-rumaitha hospital in al-muthanna, iraq. p. aeruginosa was identified by conventional biochemical assays and confirmed with the vitek 2® system. susceptibility testing was performed by disk diffusion. pcr was conducted to detect plasmid-mediated quinolone resistance determinants, namely qnra, qnrb, qnrd, qnrs, aac(6')-ib-cr, and qepa. results: among the 650 specimens analyzed, 374 (57.54%) were positive for bacterial culture, with p. aeruginosa representing 40.10% (150/374) of the identified isolates. among these, 39 (26%) exhibited resistance to at least one fluoroquinolone used. the most frequently detected gene was qnrb (67.65%), followed by qnrd (61.76%), qnrs (55.88%), aac(6')-ib-cr (47.00%), and qepa (41.17%), while qnra and qnrc were not detected in any isolate. conclusion: the fluoroquinolone resistance and widespread occurrence in isolates of p. aeruginosa from al-muthanna province pose a challenge to infection management, as mobile genetic elements facilitate the rapid dissemination of resistance and limit available therapeutic options, emphasizing the necessity for genetic monitoring and effective antibiotic management.