Multidrug-resistant Escherichia coli ST940 carrying bla

backgroundA bacterial genome continuously evolves, modifying its genetic makeup to wage a war against the antibiotics. Carbapenem-resistant Enterobacterales have challenged the efficacy of last resort antibiotics. It’s crucial to complement the phenotypic understanding of bacterial isolates with genotypic analysis, for an-in depth understanding of antibiotic resistance genes (ARGs) and characteristic features aiding the transmission of ARGs. METHODS AND

resultsIn this study, we screened community wastewater of Aligarh, a major city in northern India for the prevalence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. From antibiotic susceptibility test, we identified six E. coli and two K. pneumoniae isolates exhibiting resistance against both imipenem and meropenem. With PCR, we found one E. coli isolate out of this (AK-633) carried the high-risk carbapenemase gene blaNDM−7. The whole-genome sequencing of AK-633 revealed the gene blaNDM−7 was carried by a mosaic plasmid, plasmid_1550 harboring incompatibility types IncFII/IncFIA/IncFIB. Further, the density and diversity of transposable elements and insertion sequences indicate an active history of recombination and horizontal gene exchange, supporting the role of plasmid_1550 as a potent vehicle for the accumulation and dissemination of ARGs within bacterial populations.

conclusionThe detection of blaNDM−7, harobored by a mosaic plasmid in an E. coli ST940 strain from wastewater in our study adds to growing evidence that environmental reservoirs may significantly contribute to the emergence, maintenance, and global spread of high-risk clones and their associated resistance plasmids.