Antimicrobial resistance, genetic relatedness, and virulence in Pseudomonas aeruginosa isolates from surgical site infections: a study at Kakamega County Hospital, Kenya.

Kindiki, S.*

Masinde Muliro University of Science and Technology

There is a growing concern surrounding Pseudomonas aeruginosa (PA) infections in hospital settings, particularly in the context of surgical site infections (SSIs). PA is a notorious pathogen known for its ability to develop antimicrobial resistance (AMR) and its possession of various virulence factors that enhance its pathogenicity. The increasing resistance of PA to antibiotics, including highly effective antimicrobials, presents a significant challenge in the management of infections, especially in vulnerable patient populations undergoing surgical procedures. The study conducted at Kakamega County General Hospital (KCGH) aimed to comprehensively investigate the phenotypic and genotypic AMR patterns, genetic relatedness, and virulence determinants of PA strains isolated from SSIs. Through a cross-sectional design and purposive sampling of 329 surgical patients, PA isolates were obtained using standard microbiological techniques. The antimicrobial resistance profiles of the isolates were determined using the Kirby-Bauer disc diffusion method, revealing varying levels of resistance and sensitivity to different antibiotics. Molecular techniques and genomic analysis were employed to identify specific AMR genes, virulence genes, and assess the genetic relatedness among the PA isolates. The study uncovered the presence of multi-drug resistant strains, high-risk clones, and a diverse array of antimicrobial resistance and virulence genes in both chromosomal and plasmid DNA. Mechanisms of resistance, such as antibiotic efflux and beta-lactamase inhibition, were elucidated, shedding light on the complex interplay between genetic factors and antibiotic susceptibility. Notably, the study identified two previously unreported PA isolates specific to the region of Kenya, underscoring the importance of local surveillance and characterization of bacterial strains. One high-risk clone, designated ID017, emerged as a concerning finding, suggesting a potential for micro-evolution and adaptation to the hospital environment. The activation of quorum sensing (QS)-related virulence factors, including proteases, pigment production, and swarming motility, further highlighted the pathogenic potential of PA in causing wound infections. Overall, the findings of this study provide crucial insights for healthcare practitioners, hospital administrators, and policymakers in Kakamega County and the wider Western region of Kenya. The identification of new and high-risk clones emphasizes the urgent need for continued research and development of effective treatment strategies to combat infections caused by multidrug-resistant PA strains in healthcare settings.