Antimicrobial resistance status of small marine fishes off the coastal cities of east and west coast of India: an adaptive nanopore sequencing based metagenomics raises concerns.

Transmission of Antimicrobial resistance (AMR) through edible fishes has recently upsurged as a global health hazard owing to its potential impact on human and one health. India, as the second largest consumer of edible fish faces a high risk of AMR transmission, given the nutritional value, accessibility and affordability of fishes to people from all economic classes. The present study investigated the presence of Antimicrobial resistance genes (ARGs) in edible muscle, gills and intestines of five commercially important fishes, Nemipterus japonicus, Sardinella longiceps, Selaroides leptolepis, Stolephorus indicus, and Sardinella gibbosa sourced from two major densely populated cities of the East coast (Chennai) and the West coast (Mangalore) using adaptive nanopore sequencing technique. A total of 54 distinct ARGs associated with 12 classes of AMR were detected across both coasts with enhanced resistance observed towards aminoglycosides, macrolides, beta lactam, tetracycline and chloramphenicol. Cumulatively, the most abundant ARGs across both coasts includes cxpE, aac(3')-IIa, aac(6)-IB-cr, oqxA and oqxB. However, significant variation in the distribution of ARGs among the two coasts were studied with varying abundance patterns. Furthermore, this study predicted human pathogens such as Klebsiella sp., Escherichia sp., Staphylococcus sp. and Pseudomonas sp. as putative reservoirs of ARGs indicating potential zoonotic and foodborne transmission to humans. This study offers a novel, and in-depth characterization of edible fish associated AMR contamination in east and West coast of India, providing essential data for assessing the public health hazards posed by ARGs and the pathogenic taxa.