Overview
- CSIR‑CCMB and partner institutions published a Nature Communications study mapping antimicrobial resistance genes in sewage from Delhi, Mumbai, Kolkata and Chennai.
- Researchers analysed 447 samples collected from 19 sites between March 2022 and March 2024 using shotgun metagenomics to read resistance directly from bacterial DNA.
- Klebsiella pneumoniae was more abundant in Chennai and Mumbai, while Pseudomonas aeruginosa dominated in Kolkata, yet resistance mechanisms were largely consistent across cities.
- The team found resistance genes against tetracyclines and beta‑lactams spread more readily than those against macrolides, aided by horizontal gene transfer among bacteria.
- An SOP validated for storing samples at 4°C for up to seven days supports shipment to central hubs, and the authors urge nationwide adoption of wastewater-based surveillance.