Phenotypic and Molecular Antimicrobial Resistance Profiles of Bacteria from Wastewaters and Inanimate Surfaces of Tertiary Hospitals in Addis Ababa, Ethiopia

dc.contributor.advisorTesfaye Admassu
dc.contributor.authorMisganu Yadesa
dc.date.accessioned2026-08-12T11:36:56Z
dc.date.available2026-08-12T11:36:56Z
dc.date.issued2026
dc.description.abstractAntimicrobial resistance (AMR) is a major global public health threat driven by inappropriate antimicrobial use and the emergence of resistant organisms. In Ethiopia, AMR-associated deaths are estimated to reach 89,200 by 2030. Therefore, to assess the presence of resistant bacteria and their associated genes in hospital environments, a cross-sectional study was conducted between October 2023 and October 2025 in Addis Ababa, Ethiopia. A total of 38 samples were collected from wastewaters (WW) and inanimate surfaces (IS) of Tikur Anbessa Specialized Hospital (TASH) and Zewuditu Memorial Hospital (ZMH). Samples were processed using culture-based methods, biochemical testing, and MALDI-TOF MS (EXS3000) for bacterial identification. Antimicrobial susceptibility was determined by the Kirby–Bauer disk diffusion method, while antimicrobial resistance genes (ARGs) detected by polymerase chain reaction (PCR). A total of 92 bacterial isolates were identified, comprising 63 (68.5%) from IS and 29 (31.5%) from WW samples. Among Gram-negative bacteria, 100% of K. pneumoniae isolates exhibited a multidrug-resistant (MDR) phenotype, while 89% of S. aureus were MDR from Gram-positive. The PCR revealed high frequencies of both chromosomal and plasmid-mediated ARGs. The most frequent chromosomal genes detected were blaTEM (94%), sul1 (53%), blaCITM (38.5%) and blaCTXM (37.5%), while high frequent plasmid-mediated ARGs were blaTEM (92%), tetA (65.6%), sul1 (56%), blaCTXM (50%), blaNDM (43.8%) and less frequent genes included blaOXA-48, blaKPC, blaFOXM, blaEBCM, blaMOXM, blaDHAM and ermB. Data analysis (SPSS v.26) indicated significant association (p < 0.05) between phenotypic resistance and the presence of specific carbapenamase genes. The findings indicate a high burden of AMR in hospital environments and highlight the importance of implementing on-site hospital WW treatment and strengthening surface disinfection practices to reduce the spread of AMR.
dc.identifier.urihttps://etd.aau.edu.et/handle/123456789/8858
dc.language.isoen_US
dc.publisherAddis Abeba University
dc.subjectantimicrobial resistance
dc.subjecthospital wastewater
dc.subjectantimicrobial resistance genes
dc.subjecthospital inanimate surface
dc.subjectEthiopia
dc.titlePhenotypic and Molecular Antimicrobial Resistance Profiles of Bacteria from Wastewaters and Inanimate Surfaces of Tertiary Hospitals in Addis Ababa, Ethiopia
dc.typeThesis

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