Isolation Rate and Antimicrobial Susceptibility Profile of Enterobacteriaceae Isolated from Wastewater of Jimma Medical Center, Jimma, Southwest Ethiopia

BACKGROUND: In many developing countries, including Ethiopia, most hospitals and healthcare facilities lack proper wastewater treatment systems. As a result, untreated wastewater is directly discharged directly into nearby water bodies, posing significant environmental and public health risks. This study aimed to determine the isolation rate and antimicrobial susceptibility profile of Enterobacteriaceae species found in wastewater from Jimma Medical Center (JMC). METHODS: A cross-sectional study was conducted between July and August 2022 on 60 hospital wastewater samples collected from ten different sites within JMC. Enterobacteriaceae were isolated and identified using standard bacteriological techniques. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method. Data analysis was conducted using SPSS version 25.0 and Microsoft Excel. RESULTS: A total of seven bacterial genera were identified. Escherichia coli (31 isolates, 51.7%) and Klebsiella spp. (27 isolates, 45.0%) were the most frequently isolated species. The isolates exhibited high resistance rates to Amoxicillin-Clavulanic acid (88.4%), Ampicillin (87.0%), Tetracycline (76.5%), and Trimethoprim-Sulfamethoxazole (71.9%). Notably, 101 out of 114 isolates (88.6%) were multidrug-resistant (MDR). CONCLUSION: The high prevalence of multidrug-resistant Enterobacteriaceae in hospital wastewater indicates a serious public health concern, as these bacteria may serve as reservoirs of resistance genes that can be transferred to other pathogenic strains. This highlights the urgent need for the implementation of effective wastewater treatment systems at healthcare facilities.