Exploring microbial diversity, antibiotic resistance, and their environmental drivers in urban and peri-urban riverbed sediments of sub-tropical river basins

This study examined how urbanization affects antimicrobial resistance (AMR) in two subtropical river basins in India: the peri-urban Song River and its heavily urbanized tributaries Rispana, Bindal, and Suswa. Researchers collected 27 sediment samples across three seasons in 2024 to analyze microbial diversity, antibiotic-resistant bacteria (ARB), antibiotic residues, heavy metals, and other physicochemical factors. Findings showed that sediments from the urbanized sub-basins contained significantly more pollutants, higher concentrations of heavy metals and antibiotics, and greater loads of resistant bacteria — including ESKAPE pathogens and Enterobacterales. Both basins were dominated by the bacterial phyla Pseudomonadota and Bacillota, with common pathogenic genera such as Pseudomonas, Staphylococcus, and Acinetobacter. The study found a clear link between heavy metal and antibiotic pollution and increased AMR levels, offering valuable insights for developing policies to manage river ecosystems in rapidly urbanizing regions.