Antibiotic susceptibility profiles of bacterial species in snare wounds of selected large wild herbivores in Murchison Falls National Park, Uganda

Abstract

Snare wounds are a major threat to the health and survival of large wild herbivores in Uganda’s protected areas, predisposing them to bacterial colonization. Despite the conservation and veterinary concerns of snare wounds in wildlife animals, especially the large herbivores, little is known about the bacterial species involved and their susceptibility profiles in Murchison Falls National Park. This study was conducted to identify bacterial species colonizing snare wounds in selected large wild herbivores and establish their antibiotic susceptibility profiles. A cross-sectional study was undertaken between July 2025 and January 2026, and 31 large wildlife herbivores (African elephants (Loxodonta africana), African buffaloes (Syncerus caffer), and Nubian giraffes (Giraffa camelopardalis camelopardalis) with active snare wounds were included in the study. The animals reported with snares were tracked and immobilised for snare removal and sample collection. Swabs were aseptically collected from snare wounds and transported under cold chain to the microbiology laboratory at Makerere University for analysis. The swabs were cultured and subjected to Gram staining and biochemical tests for bacterial identification. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar, following CLSI guidelines. Data were analysed descriptively, and non- susceptibility profiles were determined against commonly used antibiotics. The study revealed that samples collected from snare wounds were colonized with diverse bacterial species, with Staphylococcus aureus (29.4%), Escherichia coli (23.5%), Klebsiella pneumoniae (17.6%), and Pseudomonas aeruginosa (14.7%) being the most prevalent. Gram-negative bacteria were predominant (64.7%) isolated from the snare wounds. Antimicrobial susceptibility testing revealed susceptibility of the isolated bacterial species to commonly used antibiotics (oxytetracycline, penicillin & streptomycin) however, high non- susceptibility to ampicillin (74.2%) and amoxicillin/clavulanic acid (58.1%) was recorded. The findings in this study revealed that snare wounds of the three large wild herbivores in MFNP were colonised with clinically significant and multidrug-not susceptible bacteria, posing risks to their health with implications on conservation efforts, and potential for transmission of not susceptible bacteria genes to other wildlife species. The study recommended integration of Antimicrobial non-susceptibility surveillance into wildlife health management program for free-ranging wildlife, strengthening the removal of snares from the conservation area through targeted patrols, enhance laboratory capacity, adopt the One Health approach and scale up long-term monitoring.