Molecular analysis of pseudomonas aeruginosa isolated from clinical and environmental sources at Uniosun teaching hospital Osogbo

Background: Pseudomonas aeruginosa is a significant public health concern due to its ubiquity and ability to cause severe infections, particularly in immunocompromised individuals. Its intrinsic resistance and propensity to develop multidrug resistance exacerbate treatment challenges. This study investigated antibiotic resistance patterns and the presence of extended-spectrum β-lactamase (ESBL) genes in P. aeruginosa isolates from clinical and environmental sources. Objectives: The study aimed to determine antibiotic resistance patterns, multidrug resistance prevalence, and the occurrence of ESBL genes (blaCTX-M, blaSHV, and blaTEM) in P. aeruginosa isolates. Methods: A total of 150 swab samples from clinical and environmental sources were collected from UNIOSUN Teaching Hospital, Osogbo, between July and December 2022. Isolation and identification of P. aeruginosa were performed using cetrimide agar and standard diagnostic tests. Antibiotic resistance was evaluated using the disc diffusion method, and ESBL gene detection was conducted using PCR. Data were analyzed and presented as tables and percentages. Results: Among 100 P. aeruginosa isolates, 66.7% were multidrug-resistant. Clinical isolates exhibited the highest resistance to ciprofloxacin, ticarcillin, and aztreonam (82%) and the lowest resistance to imipenem (22%). Environmental isolates showed similar trends, with aztreonam and ticarcillin resistance at 76% and the lowest resistance to imipenem (38%). ESBL genes blaTEM and blaSHV were detected in 5.4% of isolates, while no isolate was positive for blaCTX-M. Conclusions: The high prevalence of multidrug-resistant P. aeruginosa and β-lactamase-producing strains highlights the urgent need for targeted antibiotic development and strict hygiene protocols in healthcare settings.