Trends in Extended-spectrum β-lactamase, AmpC β-lactamase and Carbapenem Resistance among Enterobacterales in Sri Lanka: A Critical Narrative Review
D.A. Madeera Govindi Dunuarachchi *
Department of Geography, University of Peradeniya, Peradeniya, Sri Lanka and Department of Bio Medical Science, Universidad Azteca, Chalco, Mexico.
*Author to whom correspondence should be addressed.
Abstract
Extended-spectrum β-lactamase (ESBL), AmpC β-lactamase and carbapenem resistance in Enterobacterales threaten the reliability of empirical therapy and the interpretation of routine antimicrobial-resistance surveillance in Sri Lanka. This critical narrative review evaluates the available human, molecular, environmental and policy evidence, with particular attention to whether studies genuinely establish temporal trends. Peer-reviewed research and relevant institutional documents published through 24 August 2026 were identified through scholarly-source searching, reference tracing and verification of bibliographic records. Sri Lankan studies document substantial ESBL production among selected urinary and hospital isolates, alongside clinically important plasmid-mediated AmpC enzymes and diverse carbapenemase mechanisms, including OXA-48-like and NDM variants. Nevertheless, the reported proportions cannot be arranged into a coherent national time series because sampling frames, specimen types, geographical coverage, organism composition, phenotypic definitions and confirmatory testing differ markedly. Some studies intentionally enrolled resistant isolates, whereas others assessed all isolates in a laboratory population. Molecular investigations offer stronger evidence for the presence of specific enzymes and mobile genetic contexts than for their population prevalence or direction of spread. Studies of cancer patients, hospital wastewater and animal-associated environments expose additional reservoirs and high-risk settings but do not independently prove intersectoral transmission. Diagnostic co-production, altered permeability and variable carbapenemase expression further complicate the equivalence of resistance phenotype and resistance mechanism. The most defensible interpretation is that clinically significant ESBL, AmpC and carbapenemase-mediated resistance is well documented in Sri Lanka, while the magnitude and direction of national change remain inadequately established. A harmonised, denominator-explicit surveillance framework, targeted molecular confirmation and prospectively linked clinical and One Health datasets are priorities for translating isolated findings into actionable trends.
Keywords: Antimicrobial resistance, carbapenemase, CTX-M, OXA-48-like enzymes, NDM, surveillance bias, One Health, urinary tract infection