Researchers in India have identified a multidrug-resistant strain of Escherichia coli carrying the clinically important blaNDM-5 resistance gene in seafood, highlighting potential public health risks associated with antimicrobial resistance in the food supply chain.
The study analysed an E. coli isolate recovered from seafood in Mumbai using whole-genome sequencing to characterise its resistance profile, virulence factors, and genetic lineage. The strain belonged to Sequence Type 167 (ST167), an emerging extraintestinal pathogenic E. coli (ExPEC) clone increasingly associated with human infections worldwide.
Extensive Antibiotic Resistance Identified
Laboratory testing revealed that the isolate was resistant to 26 of the 33 antibiotics evaluated. Whole-genome analysis confirmed the presence of numerous antimicrobial resistance genes, including blaNDM-5, a carbapenemase gene capable of conferring resistance to some of the most important last-line antibiotics used in clinical practice.
Additional resistance genes identified included blaCMY-42, blaOXA-1, and blaTEM-116, alongside genes associated with resistance to chloramphenicol, sulphonamides, and tetracyclines. Researchers also detected mutations linked to quinolone resistance, further contributing to the strain’s multidrug-resistant profile.
Potential Human Pathogen
Genomic analysis classified the isolate as serotype O101:H9 and phylogroup A. Importantly, the strain carried multiple virulence genes associated with pathogenic E. coli, suggesting it may have the potential to cause disease in humans.
The combination of virulence factors and extensive antimicrobial resistance raises concerns about the emergence and spread of highly adapted bacterial strains capable of both causing infection and evading treatment.
Seafood as a Potential Transmission Route
The authors suggest that contamination of seafood with faecal bacteria may contribute to the dissemination of multidrug-resistant organisms within communities. As seafood products move through production and distribution networks, resistant bacteria may potentially spread beyond their original environment.
The detection of ST167 is particularly notable because this lineage has increasingly been recognised as an emerging global clone associated with antimicrobial resistance and human disease.
Strengthening Surveillance Efforts
The researchers conclude that enhanced monitoring of seafood and aquatic food production systems is needed to better understand and mitigate the spread of antimicrobial resistance through the food chain.
They note that whole-genome sequencing can play an important role in identifying high-risk bacterial strains and tracking their movement between environmental, food, and human health settings.
The findings add to growing evidence that antimicrobial resistance is not confined to healthcare environments and reinforce the importance of a One Health approach that considers human, animal, food, and environmental sources of resistant pathogens.
Reference
Dhanush CK et al. Whole genome analysis of a multidrug-resistant blaNDM−5-carrying Escherichia coli Sequence Type (ST) 167 strain isolated from seafood in Mumbai, India. BMC Microbiol. 2026;DOI: 10.1186/s12866-026-05288-x.
Featured Image: M.studio on Adobe Stock
- Author:
