ZSI-IIT M study reveals microbial diversity, antibiotic resistance in urban drinking water

Kolkata: The Zoological Survey of India (ZSI), Kolkata, and the Indian Institute of Technology Madras uncovered India's first metagenomic profile of municipal drinking water.This breakthrough could reshape the country's approach to water safety and antimicrobial resistance (AMR) surveillance.The study, published in the Journal of Environmental Chemical Engineering (Elsevier), provides a comprehensive snapshot of the microbial world hidden within treated tap water, revealing not only bacterial diversity but also the presence of antibiotic resistance genes (ARGs), such as adeF and ermR, both associated with multidrug resistance.Unlike conventional culture-based testing, which identifies only a fraction of microbes, metagenomic sequencing allows scientists to decode the entire microbial DNA present in water samples. "This is the first time in India that metagenomic sequencing has been applied to public drinking-water systems to understand microbial ecology, antibiotic-resistance profiles and their environmental drivers," said Dr Vikas Kumar, scientist-E, ZSI, and principal investigator of the project."Even treated water harbours diverse microbial life. Its composition is influenced by temperature, pipeline conditions, and other distribution-system factors. Our findings provide baseline data crucial for integrating microbial surveillance into national water-safety programmes," he added.Dr Inderjeet Tyagi, scientist at ZSI and co-supervisor of the research, said, "Water connects humans, animals and the environment — the three pillars of Centre's One Health Mission. Our study provides the environmental-health evidence base necessary for integrating microbiome monitoring into One Health frameworks."The researchers noted that ARGs in aquatic environments can easily migrate across One Health sectors, linking environmental exposure with clinical and agricultural antibiotic resistance. The findings also align with national priorities under the Jal Jeevan Mission, Swachh Bharat Mission, and National Action Plan on Antimicrobial Resistance (NAP-AMR).Prof Karthik Raman of IIT Madras emphasised the potential of the method: "Through metagenomic analysis, we can detect thousands of microbial species and potential ARGs in a single sequencing run. This supports the development of early-warning systems for antimicrobial resistance and water-borne infections."