Beta-lactamase production among multidrug-resistant wound isolates from patients attending University College Hospital, Ibadan, Oyo State, Nigeria

Background: Wound infections have been a problem in the field of medicine for a long time due to the emergence and re-emergence of drug resistance. The assessment of Beta-lactamase production, plasmid profiling and corresponding resistance pattern in the local terrain become important for a proper understanding of wound infection burden and its epidemiology. The study aimed to assess beta-lactamase production among multidrug-resistant wound isolates from patients attending University College Hospital (UCH), Ibadan. Methods: Sample size of 370 was determined using the Cochran formula. Exudates from wounds were collected with sterile swab sticks, isolation and identification were performed using standard procedures. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer disc diffusion method, Beta Lactamase Production was carried out using the starch iodide acidimetric method. Double disc synergy test and combination disk were used for extended–spectrum beta-lactamases (ESBL) and metallo-beta-lactamase (MBL) detection respectively. Plasmid curing of two beta-lactamase procedures was carried out using sodium dodecyl sulphate (SDS). After which, post-curing antibiotics susceptibility testing was performed. Results: Result shows 339 isolates of which 56.9% were multidrug-resistant. Beta-lactamase producers were 60.7% from which 5% and 14% were positive for ESBL and MBL test. Same resistance pattern to the antibiotics was observed in plasmid-cured isolates, meaning that their resistance was not plasmid-mediated. Conclusion: The establishment of beta-lactamase producing capacity in the wound isolates in this study will help clinicians in the appropriate treatment of wound infections.