Published in PLOS One on 2026-03-30, this study is presented as an attributed evidence briefing. The excerpts below are the original researchers’ words, reproduced under their Creative Commons Attribution licence. Health Signal has selected the abstract and, where needed, opening background paragraphs; the complete methods, results, limitations and references remain in the linked paper.
Original authors: Daniel Beshah, Tesfaye Sisay Tessema, Gurja Belay Woldemichael, Esmael Besufikad Belachew, Dawit Hailu Alemayehu, Abebech Tesfaye, Dessalegn Abeje Tefera, Solomon Gizaw Derese, Tizazu Zenebe Zelelie, Abera Admasie, Tamrat Abebe, Adey Feleke Desta
Source: PLOS One • DOI 10.1371/journal.pone.0344856
Read the complete primary study ↗ · Creative Commons Attribution licence
From the researchers
Abstract
The global rise in antimicrobial resistance is largely driven by DNA-encoded, antibiotic-hydrolyzing enzymes. This study aimed to determine the prevalence of ESBL, AmpC-BL, MBL, and carbapenemase genes. A cross-sectional study was conducted from September 2018 to March 2019 using standard microbiological and molecular methods. Among 231 Gram-negative bacterial isolates, 176 (76.2%) carried beta-lactamase genes confirmed by PCR. ESBLs were detected in 117 (50.6%), MBLs in 50 (21.6%), carbapenemases in 46 (19.9%), and AmpC-BLs in 22 (9.5%). The most frequent carriers were Klebsiella pneumoniae, Escherichia coli, and Acinetobacter species. The dominant ESBL genes were blaCTX-M (85.2%) and blaTEM (79.5%), with blaBEL (17.2%) surpassing blaSHV (9.8%), indicating a shift in resistance patterns, while among AmpC genes, blaFOX (39.4%) and blaCITM (36.4%) were the most prevalent. The blaOXA-23 (40.6%) and blaKPC (14.5%) were the most common carbapenemase genes, while blaNDM (39.1%) and blaVIM (34.8%) dominated among MBLs. The high prevalence of blaOXA-23 in Ethiopia is a significant finding, which I have not found evidence of in similar African or Asian settings. A comparable trend in Taiwan suggests medical tourism may contribute to the spread of resistant bacteria. These findings highlight the critical importance of continuous molecular surveillance and indicate that factors like medical tourism may contribute to the international dissemination of resistant strains.
Introduction
Antibiotic-resistant gram-negative bacteria (GNB) due to beta-lactamases and carbapenemases are a major cause of morbidity, mortality, and significant economic costs worldwide, and their incidence and spread are on the rise [1–3]. These antibiotic resistance determinants are passed from one bacterial community to another through horizontal gene transfer mechanisms [1,4]. The beta-lactamase-mediated resistance is increasingly associated with Plasmid-Encoded Extended-spectrum beta-lactamase (ESBL) and Carbapenemase, sometimes in combination with other resistance mechanisms (e.g., porin loss, efflux pumps, target site alteration) [4,5].
Beta-lactamases, which are produced by bacteria, lead to a variety of beta-lactam antibiotic resistance, including penicillin, cephalosporin, cephamycin, monobactam, and carbapenem [6]. The major blaCTX-M, blaSHV, blaTEM, and minor blaGES, blaVEB, blaBEL, and blaPER genes that produce ESBL enzymes are capable of hydrolyzing penicillin, monobactams, and third-generation cephalosporins and are inhibited by beta-lactamase inhibitors except for blaKPC, which can hydrolyze carbapenem drugs and beta-lactamase inhibitors [7]. The blaMOX, blaCIT, blaDHA, blaACC, blaEBC, and blaFOX genes, classified as AmpC-beta-lactamases (AmpC-BL), hydrolyze penicillins, monobactams, broad and extended-spectrum cephalosporins, and cephamycin but are sensitive to Cefepime [8,9]. The major blaNDM-1, blaIMP, blaVIM, and the minor blaGIM-1, blaSIM-1, blaAIM-1, blaDIM, and blaSPM-1 genes that produce carbapenem-resistant MBL enzymes are metalloproteins and are capable of hydrolyzing all (third-generation cephalosporin, cephamycin, and carbapenem) antibiotics except monobactams [5]. The blaOXA-23-group, blaOXA-24-group, blaOXA-48, and blaOXA-58-group genes are oxacillinase derivatives, like blaKPC and blaIMI Carbapenemase, their hydrolytic activity against carbapenems and some 3rd generation cephalosporins, including monobactam, and they are not inhibited by clavulanic acid and tazobactam [5].
Reading this evidence
Use the full paper to check the study design, participant selection, comparator and outcome definitions before drawing a practical conclusion. An association does not by itself show cause and effect. A reported performance measure needs its denominator and uncertainty. A finding from a particular facility, sample or time period should retain that scope when it is discussed elsewhere.
This briefing makes the source accessible within the wider research & evidence desk. It does not assess an individual patient or certify a product. When considering relevance to another health system, examine the original authors’ account of context and limitations, then seek local implementation evidence. The related reporting below provides other studies to read alongside this one; it is a topic connection, rather than a claim that their results are directly comparable.
© 2026 Daniel Beshah, Tesfaye Sisay Tessema, Gurja Belay Woldemichael, Esmael Besufikad Belachew, Dawit Hailu Alemayehu, Abebech Tesfaye, Dessalegn Abeje Tefera, Solomon Gizaw Derese, Tizazu Zenebe Zelelie, Abera Admasie, Tamrat Abebe, Adey Feleke Desta. Excerpts reproduced under CC BY. Selection, formatting and contextual notes by Health Signal. The researchers are the authors of the source study, not members of Health Signal’s staff.
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- Evidence brief: Bacterial isolates and antimicrobial susceptibility profiles of pediatric meningitis at comprehensive specialized hospitals in Bahir Dar, Northwest Ethiopia
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- Evidence brief: Fecal carriage of ESBL and Carbapenemase-producing Enterobacteriaceae, and its associated factors among hospital and non-hospital janitors at the University of Gondar, Northwest Ethiopia: A comparative cross-sectional study
