Detection of antimicrobial resistance genes (ARGs) in surface waters and the anthropogenic factors influencing its abundance: A systematic review

Abstract

Antimicrobial resistance (AMR) is a global public health threat, and several studies have aimed to identify resistant pathogens and/or associated antimicrobial resistance genes in surface waters. A systematic review of 98 studies was done to obtain a bigger picture of detecting antibiotic resistance genes (ARGs) across surface waters and the factors influencing its abundance. Available data revealed a high abundance and detection rate of ARGs conferring resistance to critically important antibiotics. Tetracycline and sulfonamide resistance genes were the most frequently studied within the past 10 years. The highest reported abundance of ARGs is up to 1011 copies per mL for ermF gene, quantified using quantitative PCR (qPCR). More advanced methods such as metagenomic sequencing, digital droplet PCR (ddPCR), and high-throughput quantitative PCR (HT-qPCR) identified greater numbers of ARGs per run compared to the conventional PCR and qPCR methods. This study emphasized the role of surface waters in the dissemination of ARGs. Surface waters not only harbor ARGs but are also significantly influenced by human activities, which alter ARG concentrations, demonstrating a two-way relationship between human activities and the environment, where surface waters serve both as recipients and conduits of ARGs, reflecting the complex interplay between anthropogenic influences and environmental systems. Recommendations for future directions in AMR surveillance studies are also provided.