Occurrence and Antimicrobial Resistance Profiles of Pseudomonas aeruginosa Isolated from Urine and Soil Samples in Selected Healthcare Facilities in Lafia, Nigeria

Abstract

Background: Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium associated with healthcare-related infections and environmental persistence. Its ability to develop antimicrobial resistance is an important public health concern in clinical and environmental settings. Aim: This study assessed the occurrence, antimicrobial susceptibility profile, and multidrug-resistance pattern of P. aeruginosa isolated from urine and soil samples obtained from selected healthcare facilities in Lafia Metropolis, Nasarawa State, Nigeria. Exploratory plasmid profiling and curing were undertaken in selected multidrug-resistant isolates. Methods: A total of 135 samples, comprising 90 midstream urine samples and 45 soil samples, were collected from three healthcare facilities between February and May 2023. Isolation and identification of P. aeruginosa were performed using standard microbiological and biochemical procedures. Antimicrobial susceptibility testing was carried out using the Kirby–Bauer disc diffusion method. Multidrug-resistance patterns and multiple-antibiotic-resistance index values were determined. Selected multidrug-resistant isolates underwent plasmid profiling and acridine-orange treatment, followed by repeat susceptibility testing. Results: Pseudomonas aeruginosa was recovered from 62.2% of soil samples and 26.7% of urine samples; there were no statistically significant differences between healthcare facilities. Resistance was highest to ampicillin, nalidixic acid, and amoxicillin–clavulanate, whereas ciprofloxacin showed no resistance among the tested isolates. Multiple-antibiotic-resistance index values ranged from 0.3 to 0.8. In six selected multidrug-resistant isolates, plasmid bands were observed and resistance phenotypes changed after acridine-orange treatment in several isolates. Conclusion: Antimicrobial-resistant P. aeruginosa occurred in both urine and soil samples from the study area. The plasmid profiling and curing findings provide preliminary evidence of a possible plasmid contribution to resistance phenotypes, but they do not identify plasmid-borne resistance genes or confirm plasmid-mediated resistance. Routine surveillance, antimicrobial stewardship, environmental hygiene and confirmatory molecular studies are recommended.