Metagenomic insights into microbial community, antibiotic resistance genes, and virulence factor in Saryu River...

A river confluence is an important ecosystem to investigate the microbial community and functional profile. Even after the enormous applications of trace elements and antibiotics, their release into the environment causes pollution and selective pressure that facilitate the proliferation and dissemination of resistance genes against antibiotics, metals and biocides among bacterial communities. Metagenomic exploration plays a pivotal role in deciphering riverine ecosystems and offers valuable insights for the mitigation of pollution and the dissemination of resistance genes. Monitoring microbial diversity could aid in identifying various prokaryotes, pathogens, and pollutants, including dyes and their associated resistance genes. Therefore, we aimed to elucidate the occurrence of resistance genes and virulence factors in the microbial community of Saryu River water using high-throughput metagenomics coupled with bioinformatic analyses. The highly dominant antibiotic resistance gene (ARG) types identified were rifampin, tetracycline, macrolide, polymyxin and rifampicin multidrug/efflux. ARGs such as rpoB2, Txr, adeF, tetB(P), and acrB were found to be abundant in Saryu River water. Among the detected MRG subtypes, namely, ruvB and arsB, the most abundant are in water. Further, the biocides against which the resistance was identified were ethidium bromide, triclosan, sodium dodecyl sulfate, etc. Among the virulence factors, tufa, htpB (adherence), Gmd (immune-modulation), cheD (motility), and clpV1 (effector-delivery-system) were found to be highly prevalent. Taxonomic classification revealed that Cyanobateriota, followed by Pseudomonadota (Proteobacteria) and Bacteroidota were the dominant phyla in the river water. Microcystis was the most dominant genus, followed by Desulfomicrobium and Dechloromonas. The present study shows that antibiotics and metals are the major sources of resistance genes development and dissemination in the environment.. Further, this is a preliminary study based on a single composite sample, representing a "snapshot" at a specific time and location. The present study highlights the persistence of ARGs, MRGs, biocides, and virulence factors in Saryu River water and provides valuable baseline data for risk assessment.