Antibacterial susceptibility profile of Pseudomonas and related bacterial species associated with wound infections in Calabar, Nigeria

Abstract

The infection of wounds by Pseudomonas species has till date posed a great deal of medical concern, owing largely to the potential severity of their infections and high transmissibility of the pathogens, both in hospital settings and in the community. This study sought to identify the species of Pseudomonas and other related bacteria implicated in wound infections as well as provide therapeutic guidelines for the species so identified. Fifty presumptive Pseudomonas spp. were identified using simple microbiological identification procedures. Further identification using the API 20NE identification system was carried out. Antibiotic susceptibility pattern was determined by the modified Kirby-Bauer disk diffusion method against a panel of antimicrobials of standard strength. IBM SPSS version 20.0 was utilized for statistical analysis of data obtained and statistical significance was drawn at p≤0.05. Results show profound misidentification of these species by the use of simple manual microbiological identification methods alone, while revealing the high occurrence of Burkholderia in wound infections. As a result of the more advanced API 20NE ® identification method employed, it was noted that there was a high prevalence of Burkholderia cepacia across the age categories, and the infection of wounds peaked around age groups >1-10 years and 11-20 years, who are known to have more exposure to outdoor activities. Results showed that Imipenem produced the highest potency against all isolates whereas Ticarcillin/Clavulanic acid had no antibiotic activity on all isolated pathogens. This study emphasizes the need for the incorporation of more advanced bacterial identification methods in our routine laboratory practice in order to forestall misdiagnosis. The study also highlights the higher occurrence of Burkholderia cepacia in wounds than P. aeruginosa.