Genomic Insights into Carbapenem-Resistant Organisms Producing New Delhi Metallo-β-Lactamase in Live Poultry Markets.

New Delhi metallo-β-lactamase (NDM) is an enzyme that can degrade a wide range of β-lactam antibiotics. The widespread dissemination of the gene, which encodes NDM, in animal-derived settings poses a threat to public health security. Live poultry markets represent critical nodes in public health surveillance. However, there is currently limited reporting on the spread of the gene within these markets under the One Health approach. This study investigated the prevalence of the gene in live poultry markets and, by integrating newly sequenced genomes with publicly available database entries, performed an in-depth analysis of its association networks with other genetic elements across species. A total of 233 -positive strains, comprising 218 strains, 4 strains, 7 , 2 , 1 , and 1 were isolated from two live poultry markets in Jiangsu, China. Among the -positive strains, multiple variants were identified, primarily , followed by , , , and . The coexistence of and was detected in five strains. Additionally, we found one strain in which coexisted with and (X4), and another strain where coexisted with . Spearman correlation analysis of publicly available genomes revealed that the genetic element preferences of variants vary significantly across species (|R| > 0.3, < 0.05). The element preferences of strains carrying are similar to those of harboring . In , , and , strains carrying , have opposite genetic element preferences when compared with strains harboring or . Notably, we report the first evidence of the gene transfer mediated by IS, IS, and MITE. The findings highlight that live poultry markets are important transmission hotspots of AMR and thus require continuous surveillance.