Bacterial contamination and antimicrobial susceptibility patterns of isolates from doorhandles at a public university campus in Uganda: A cross-sectional study.

Background: Door handles are frequently touched surfaces that can serve as fomites for transmission of pathogenic and antimicrobial-resistant bacteria. However, contamination of door handles in university settings in low-resource countries remains poorly characterised. This study determined the prevalence, bacteriological profile and antimicrobial susceptibility of bacterial contaminants on door handles at Mbarara University of Science and Technology (MUST) City Campus, Uganda. Methods: A laboratory-based cross-sectional study was conducted using stratified random sampling across hostels, lecture rooms, toilets, laboratories and offices. One hundred door handles were swabbed in the evening using a standardised technique and processed within 24 hours. Samples were cultured on blood and MacConkey agar. Bacterial isolates were identified using colony morphology, Gram staining and standard biochemical tests. Antimicrobial susceptibility was determined using the Kirby-Bauer disc diffusion method according to CLSI guidelines. Results: Of the 100 door handles sampled, 53 (53.0%) yielded bacterial growth, producing 59 isolates from five species, including three cases of polymicrobial contamination. Contamination was highest on toilet door handles (68.2%) and lowest on laboratory handles (20.0%). Gram-positive cocci predominated (89.8%), with Staphylococcus hyicus (47.5%) and Staphylococcus aureus (40.7%) being the most common isolates. Other organisms included Klebsiella pneumoniae (8.5%), Hafnia species (1.7%) and Staphylococcus saprophyticus (1.7%). High antimicrobial resistance was observed against azithromycin (61.0%), tetracycline (44.1%) and penicillin (40.7%). Gentamicin showed the greatest activity, with only 8.5% resistance, followed by chloramphenicol (20.3%). Resistance to cefixime and ceftriaxone among Gram-negative isolates suggested possible extended-spectrum beta-lactamase (ESBL) production, although these drugs were tested on only six isolates. Conclusion: Door handles at MUST City Campus harbour a substantial burden of bacterial contamination, including potentially pathogenic and antimicrobial-resistant organisms. This highlights the potential role of frequently touched surfaces in microorganism transmission within university environments. Recommendations: Routine disinfection of frequently touched surfaces, particularly toilet door handles, should be strengthened alongside improved hand hygiene and prudent antimicrobial use. Further studies should incorporate molecular confirmation of bacterial identification and resistance mechanisms, as well as minimum inhibitory concentration testing.