Occurrence and Antibiotic Susceptibility of <i>Escherichia coli </i>from Door Handles in the Faculty of Pharmacy, Nnamdi Azikiwe University, Agulu

Door handles are high-contact surfaces that can serve as reservoirs for pathogenic microorganisms, including Escherichia coli, a significant cause of community- and hospital-acquired infections. Increasing antibiotic resistance among E. coli strains poses a public health challenge, necessitating local surveillance. This study investigated the prevalence of E. coli contamination on door handles within the Faculty of Pharmacy, Nnamdi Azikiwe University, Agulu, and assessed the antibiotic susceptibility patterns of the isolates. A total of 100 swab samples were collected from door handles across offices, classrooms, hostels, laboratories, clinic, and other locations. Samples were cultured in nutrient broth, subcultured on MacConkey agar, and pure isolates identified using Gram staining, cultural characteristics and biochemical tests. Antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar with 12 commonly used antibiotics. Data were analyzed using CLSI breakpoints and Multiple Antibiotic Resistance Index (MARI) was used to assess multidrug resistance. Seventeen E. coli isolates were recovered, with the highest prevalence from hostel door handles (59%). Antibiotic susceptibility testing revealed high resistance to β-lactams, including Ampicillin/Sulbactam (94%) and Piperacillin/Tazobactam (88%), as well as third- generation cephalosporins such as Cefotaxime (82%). Conversely, 100% susceptibility was observed for Gentamicin, Azithromycin, and Chloramphenicol, while Ofloxacin and Levofloxacin retained significant activity (88% susceptibility). Twelve isolates (71%) exhibited multidrug resistance, with MARI values >0.2, suggesting exposure to high antibiotic pressure. The findings highlight the role of fomites in harboring multidrug-resistant E. coli, underscoring the need for improved hygiene practices, routine surveillance, and rational antibiotic use within academic environments.