Phenotypic and genotypic landscape of antibiotic resistance through One Health approach in Sri Lanka: A systematic review.

Objectives: Antibiotic resistance (ABR) constitutes a significant burden to economies in developing countries. In the 'One-Health' concept, ABR in human, animals, and environment is interconnected. The aim of this study was to critically appraise literature on ABR in all three domains in One Health, within the Sri Lankan geographical context.

Methods: The protocol was registered with PROSPERO and followed PRISMA 2020 guidelines. A comprehensive electronic literature search was conducted in PubMed, Scopus, Web of Science databases and grey literature via Google Scholar. Out of 298 abstracts, 37 articles were selected following screening. A risk of bias assessment was conducted using Joanna Briggs Institute tools. Following blinded data extraction, descriptive data analysis and narrative synthesis were performed.

Results: This review included studies published between 2016-2023. Of the included studies, 17 (45.9%) reported data on samples obtained from humans, 9 (24.3%) from animals, and 6 (16.2%) from environmental sources, two studies (5.4%) from humans and animals, one study on animal and environment; whereas two studies including all three domains. ABR of 32 different bacteria (Gram negative⸺17, Gram positive⸺14) was retrieved; E. coli was the most frequently studied bacteria followed by MRSA and ESBL. For E. coli, a median resistance over 50% was reported for sulfamethoxazole (88.8%), trimethoprim (79.1%), ampicillin (60%) and tetracycline (50.3%) with the highest resistance for erythromycin (98%). Of a total of 21 antibiotic-resistance genes in E. coli, the highest genotypic resistance was for tet-A (48.5%).

Conclusions: A comprehensive description of ABR for a total of 32 bacteria, 62 antibiotics and 46 ABR genes is presented. This review discusses the contemporary ABR landscape in Sri Lanka through the One Health lens, highlighting key methodological and empirical research gaps.