Phenotypic and genotypic determination of some virulence genes associated with Pseudomonas aeruginosa clinical isolates

Background: Pseudomonas aeruginosa is a prevalent cause of post-surgical wound infections due to its ability to withstand extreme conditions and its multiple virulence factors. This study aimed to phenotypically and genotypically analyze virulence genes associated in P. aeruginosa clinical isolates from post-surgical wounds and assess their antimicrobial resistance patterns. Methods: A total of 100 wound swabs were collected from patients with post-surgical infections. Routine culture and biochemical identification were performed, and results were confirmed by the DL microbiology identification system. Antibiotic susceptibility tests assessed resistance patterns, while phenotypic expression of virulence factors was evaluated using various agar media. DNA extraction and PCR amplification targeted virulence genes: LasR (quorum sensing), LecA (galactophilic lectin), plc (hemolytic phospholipase C), and ToxA (exotoxin A). Results: Among the 100 wound swabs, P. aeruginosa was identified as the leading pathogen, accounting for 24% of infections. All isolates exhibited 100% positivity for biofilm production, protease, and hyaluronidase. Antimicrobial susceptibility showed 100% resistance to penicillin and ampicillin, while sensitivity to imipenem and meropenem was 83.3% and 87.5%, respectively. The prevalence of target virulence genes was highest for ToxA (95.8%), followed by LecA (91.6%), PlcH (83.3%), and LasR (66.6%). Conclusions: This study provides a comprehensive analysis of P. aeruginosa virulence factors in post-surgical infections among the Iraqi population, highlighting a unique virulence gene profile and emphasizing the need for tailored infection control strategies in resource-limited settings.