Retrospective analysis of antibiotic resistance profiles and resistance gene prevalence in Pseudomonas aeruginosa clinical isolates

Retrospective Analysis of Antibiotic Resistance Profiles and Resistance Gene Prevalence in Pseudomonas aeruginosa Clinical Isolates Objectives: This study aims to retrospectively determine the antibiotic resistance profiles of P. aeruginosa clinical isolates, a significant pathogen in healthcare-associated infections, and the frequency of carbapenemase resistance genes involved in carbapenem resistance. Materials and Methods: The study was conducted on 108 isolates collected from various clinical departments between 2021 and 2023 at the Medical Microbiology Laboratory of Balıkesir University Faculty of Medicine. Antibiotic susceptibility testing was performed using the BD Phoenix™ M50 (Becton Dickinson, USA) automated system and results were interpreted according to EUCAST criteria. The presence of various carbapenemase genes (VIM, IMP, NDM, OXA-23, OXA-24, OXA-48) was investigated using polymerase chain reaction (PCR). The obtained data were analyzed retrospectively. Results: The P. aeruginosa isolates demonstrated resistance to a broad range of antibiotics. The highest resistance rates were observed for levofloxacin (35.5%), ciprofloxacin (34.9%), cefepime (32.6%) and imipenem (32.4%). Notably, high resistance rates to carbapenems were evident. PCR screening identified five isolates producing VIM and one isolate producing NDM, while other carbapenemase genes were not detected in any isolates. Conclusions: The study highlights the significant resistance threat posed by P. aeruginosa isolates, which limits treatment options. Identifying antibiotic resistance mechanisms contributes to the development of infection control measures and effective treatment strategies. Additionally, the prevalence of carbapenemase genes underscores the importance of regional surveillance of infections caused by this pathogen. Keywords: Carbapenem Resistance, Metallo-Beta-Lactamases, OXA-Type Carbapenemases, Polymerase Chain Reaction, Pseudomonas aeruginosa