CHARACTERIZATION OF PSEUDOMONAS AERUGINOSA RECOVERED FROM SURGICAL SITES AT KAKAMEGA COUNTY GENERAL HOSPITAL

Abstract

Pseudomonas aeruginosa is a significant pathogen in surgical site infections (SSIs) due to its diverse virulence factors and high antibiotic resistance. It is important to understand its prevalence, resistance profiles, genotypic diversity, and physiological attributes in order to formulate effective treatment and infection control strategies. The objective of the investigation was to ascertain the prevalence of P. aeruginosa among bacterial isolates from surgical sites, evaluate the antibiotic resistance profiles of these isolates, assess their genotypic diversity, and determine major physiological characteristics that contribute to their pathogenicity. Standard microbiological techniques were employed to confirm the presence of P. aeruginosa isolates among the 128 bacterial isolates collected and identified from surgical sites. The disc diffusion method was employed to conduct antibiotic susceptibility testing. Sequence typing and phylogenetic analysis were employed to investigate genotypic diversity. Protease secretion, motility, exoprotein production, pigment production, and quorum sensing (QS) activity were evaluated to ascertain their contribution to virulence. In order to identify resistance patterns and ascertain the susceptibility of isolates to a variety of antibiotics, a statistical analysis of antibiotic resistance data, including MIC values, was performed. The genetic relationships among the isolates were revealed through the construction of phylogenetic trees using sequence typing data. Categorical variables were investigated using chi-square analysis, with a significance level of P<0.05. Principal component analysis (PCA) was employed to identify clustering patterns associated with biofilm formation and QS activity, and physiological data were analysed to compare the virulence characteristics of various isolates. P. aeruginosa was identified as the most prevalent bacterium, accounting for 38.9% of the isolates. The antibiotic susceptibility testing demonstrated significant multidrug resistance, with resistance rates of 60.7% for Ceftazidime, 60.7% for Ciprofloxacin, and 71.4% for Amikacin. Meropenem demonstrated the maximum sensitivity, with a value of 53.6%. Genotypic analysis revealed substantial diversity, including multiple sequence types (STs) and distinct phylogenetic clusters, which suggest both genetic variability and clonal dissemination. Physiological evaluations demonstrated that protease secretion, motility, exoprotein production, and QS activity were subject to variation, with certain isolates exhibiting heightened pathogenic potential. The study emphasises the high prevalence and multidrug resistance of P. aeruginosa in surgical site infections, as well as the significant genotypic diversity and complex physiological traits that contribute to its pathogenesis. These results underscore the necessity of enhanced infection control, targeted antibiotic stewardship, and ongoing research into innovative therapeutic strategies to effectively manage P. aeruginosa infections.