Pseudomonas species Implicated in Nosocomial Infections in a Referral Health Facility in Uyo, Southern Nigeria

Background: Nosocomial infection is posing problems in developing countries like Nigeria especially in the face of emerging and re-emerging multidrug-resistant strains of infectious organisms plaguing the hospitals. The objective was to investigate nosocomial P. aeruginosa pathogens in urine and wound samples, their antibiotic resistance patterns, and the resistance genes involved. Methods: A total of 210 samples, comprising 110 urine and 100 wound samples, were processed using standard methods. The pathogens isolated were identified using microbiological techniques, biochemical tests, and the Macrobact™ 24E system kit. Antibiotic susceptibility, plasmid DNA extraction, and detection of resistance genes were determined using the modified Kirby Bauer disc diffusion, alkaline lysis method, and multiplex polymerase chain reaction, respectively. Results: Of the 129 bacteria isolates identified as nosocomial pathogens, 35 (16.7%) were P. aeruginosa and were found to be more resistant to Piperacillin-Tazobactam 12 (75.0%) and 10 (52.6%) for urine and wounds, respectively, and relatively sensitive to Ceftazidime 10 (62.5%) for urine and 6 (36.8%) for wounds. All isolates of P. aeruginosa had single plasmids with molecular weights of 10.5 kb and above, and antibiotic resistance genes detected were QnrA, QnrB, GMr, AmpC, and VIM. Conclusion: The study revealed P. aeruginosa were associated with nosocomial wound and urinary tract infections at a 16.7% rate, and antibiotic resistance were plasmid mediated with QnrA, QnrB, GMr, AmpC, and VIM as resistance genes.