Molecular characterization of plasmid-mediated quinolone resistance genes in clinical isolates of Pseudomonas aeruginosa from Al-Muthanna Province, Iraq

Sarah A. Al- Khafaji; Firas Srhan Abd  Al-Mayahi

doi:10.18502/ijm.v18i2.21300

Sarah A. Al- Khafaji Department of Microbiology, College of Veterinary Medicine, Al-Muthanna University, Al-Muthanna, Iraq
Firas Srhan Abd Al-Mayahi Department of Biology, College of Science, University of Al-Qadisiya, Al-Qadisiya, Iraq

DOI: https://doi.org/10.18502/ijm.v18i2.21300

Keywords: Pseudomonas aeruginosa; Drug resistance; Fluoroquinolones; Ciprofloxacin; Levofloxacin; Polymerase chain reaction; Ofloxacin

Abstract

Background and Objectives: Fluoroquinolones represent a class of antibiotics commonly used to manage Pseudomo- nas 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 biochem- ical assays and confirmed with the Vitek 2® system. Susceptibility testing was performed by disk diffusion. PCR was con- ducted 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 represent- ing 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 re- sistance and limit available therapeutic options, emphasizing the necessity for genetic monitoring and effective antibiotic management.