CCMB maps antimicrobial resistance in Indian urban wastewater

Researchers from CCMB have mapped antimicrobial resistance (AMR) in urban wastewater across Delhi, Mumbai, Kolkata, and Chennai. The study reveals consistent bacterial resistance mechanisms, gene-sharing patterns, and a practical SOP enabling nationwide surveillance of drug-resistant pathogens.

Hyderabad: In a study published in Nature Communications, researchers from Hyderabad-based Centre for Cellular and Molecular Biology (CCMB) have released the first comprehensive map of Antimicrobial Resistance (AMR) found in Indian urban wastewater.

Conducted between March 2022 and March 2024, the team analysed 447 samples from 19 sites across Delhi, Mumbai, Kolkata, and Chennai.

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The analysis of samples was done using the shotgun metagenomics approach, which allowed scientists to bypass traditional lab cultures and look directly at bacterial genes to understand how they resist life-saving antibiotics.

The findings revealed that while different cities had different dominant bacteria, for instance, Klebsiella pneumoniae was more prevalent in Chennai and Mumbai, while Pseudomonas aeruginosa led in Kolkata, the actual mechanisms used by these bacteria to survive drugs remained remarkably consistent across all four metros.

The study highlighted that these ‘superbugs’ employ several tactics, such as strengthening their cell walls, flushing out antibiotic molecules, or destroying the medicine entirely. Crucially, the researchers discovered that bacteria can share resistance genes against tetracyclines and beta-lactams much more easily than against macrolides, passing these traits not just to their offspring but to neighbouring microbes.

To combat this ‘silent pandemic’, the CCMB team developed a practical Standard Operating Procedure (SOP) that allows wastewater samples to be stored at 4 degrees Celsius for up to seven days without losing data quality, Dr Vinay K Nandicoori, Director, CSIR-CCMB, said.

The breakthrough enables samples from resource-limited areas to be sent to central testing hubs, paving the way for a nationwide surveillance system that can detect early outbreaks and track the spread of drug-resistant pathogens in real-time, CCMB researchers added.