High prevalence of Antibiotic Resistance Bacteria isolated from Municipal Solid Waste Dumpsite, Bahir Dar, Ethiopia

Abstract Background The emergence of antibiotic resistance (ABR) among environmental microbes has been challenging global health. ABR can be transferred to human-associated bacteria aggravating the spread of antimicrobial resistance. Due to poor solid waste disposal practices, municipal solid waste dumpsite (MSWDS) can be a reservoir for antimicrobial resistant microorganisms, such as bacteria. This study aimed to assess the prevalence of antibiotic resistance (ABR) bacteria at Bahir Dar city MSWDS. Methods Soil samples were collected from three randomly selected sites within the dumpsite from November 2020 to May 2021. Bacteria were isolated, identified and tested for ABR using standard procedures. Results In this study, 71 distinct colonies were isolated and identified to ten bacterial genera based on cultural characteristics and biochemical tests. The pooled antibiotic résistance rate was 85.9%. Resistance to the tested antibiotics ranged between 0% for erythromycin and 100% for amoxicillin among the bacterial isolates. High proportions of the isolates were found to be resistant to amoxicillin (100%), vancomycin (87%) and nalidixic acid (73.3%). Substantial proportions of the isolates were also resistant to Streptomycin (54.5%), sulfonamide (50%) and tetracycline (48.5%). On the other hand, high sensitivity rates to erythromycin (90.91%), ciprofloxacin (83.10%), chloramphenicol (77.46%) and gentamicin (63.49%) were recorded. All isolates related to Staphylococcus spp., and most isolates related to Pseudomonas, Escherichia, Klebsiella, Salmonella, Enterococcus, Citrobacter, Shigella and Proteus species were resistant at least to one antibiotic drug. The overall multidrug resistance (MDR) rate was 49.3%, and a high rate of MDR was demonstrated among isolates related to Escherichia spp. (75%), Staphylococcus spp. (68.8%), Pseudomonas spp. (62.5%) and Klebsiella spp. (60%), where each isolate resisted at least 5 antibiotic drugs. Conclusion From the present study, it can be concluded that a high incidence of ABR exists in Bahir Dar city MSWDS. The occurrence of the high level of ABR to commonly used antibiotics in this study demands a proper waste management system, as well as surveillance programs to monitor for antimicrobial resistance determinants in municipal solid wastes. Moreover, detailed studies on the isolates and ABR genes will give a better insight into the prevalence of ABR in the waste dumpsite.