Antibiotic Resistance Pattern of Pseudomonas spp. from Patients in a Tertiary Hospital in South-West Nigeria

Introduction: Pseudomonads constitute critical agents of opportunistic infections in hospital settings particularly in immunocompromised patients and Pseudomonas aeruginosa is a major flagship member of these infectious agents. This study assessed the distribution of Pseudomonas spp. associated with infections in patients and their antibiotic resistance patterns as part of an antibiotic stewardship intervention program and resistance surveillance. Methods: One hundred and fifty Pseudomonas spp. from different clinical specimens were obtained from the Obafemi Awolowo University Teaching Hospitals Complex Ile-Ife. Culture was carried out on MacConkey and blood agar while phenotypic characterization was done by Gram staining, oxidase, and catalase test. Species identification was done using MICROBACT^TM 24E bacterial identification kit and confirmed by 16S rDNA polymerase chain reaction (PCR) assay. Antibiotic susceptibility testing to eight antibiotics in four classes was done. Results: Pseudomonas aeruginosa was the most frequently occurring species (96.0%); P. putida (2.67%) and P. fluorescens (0.67%) were also identified as well as an isolate of Burkholderia pseudomallei (0.67%). The highest resistance rate among isolates was observed towards gentamicin (35.4%); piperacillin/tazobactam was the most active antibiotic. Multidrug-resistant (MDR) strains constituted 12.8% of the isolates and most MDR strains also displayed a high multiple antibiotic resistance index (MAR). Conclusions: Pseudomonas aeruginosa is emerging as a highly MDR pathogen in our hospital setting. This calls for the establishment of a surveillance system and antimicrobial stewardship programme in place. Furthermore, we propose a review of the current antibiotics prescription policy, and infection control programmes (ICPs) if we must control the spread of MDR-P. aeruginosa in this environment.