Antimicrobial susceptibility of potentially pathogenic bacteria isolated from diabetic foot ulcers of patients at Mulago and Kirudu national referral hospitals.

Abstract

Background: Diabetic foot infections are a major cause of morbidity among patients with diabetes mellitus. Knowledge of local microbial profiles and antimicrobial susceptibility patterns is essential for guiding effective empirical therapy. This study aimed to determine the common microbial pathogens and their antimicrobial susceptibility patterns in diabetic foot ulcers at Mulago and Kiruddu hospitals. Methods: A cross-sectional study was conducted among 80 patients with diabetic foot ulcers. Wound specimens were collected and processed using standard microbiological techniques. Data were analyzed descriptively to determine the common microbial isolates and their susceptibility patterns. Results: Out of 80 samples, 168 bacterial isolates were obtained from 79 culture-positive patients, with 58 (73.4%; 95% CI 62.8–81.9%) patients having polymicrobial and 21 (26.6%) monomicrobial infection. Overall, Gram-negative bacteria predominated (132/168; 78.6%; 95% CI 71.8–84.1%), with Escherichia coli (39/168; 23.2%) being the most common isolate, followed by Gram-positive Enterococcus spp. (23/168; 13.7%) and Klebsiella pneumoniae (20/168; 11.9%). Multidrug-resistant organisms were identified in 74.4% of isolates. Linezolid and chloramphenicol were effective against Gram-positive organisms, including MRSA and VRE, while carbapenems and amikacin were effective against Gram-negative isolates. High resistance rates were observed to penicillins, erythromycin, fluoroquinolones, and cephalosporins. Conclusion: The study found a high prevalence of polymicrobial infections, predominantly Gram-negative bacteria, with approximately three-quarters of isolates being multidrug-resistant. Common first-line antibiotics showed high resistance, leaving limited effective treatment options.