Transmission patterns of multiple strains producing New Delhi metallo-β-lactamase variants among animals and the environment in live poultry markets

Abstract

The widespread transmission of blaNDM among livestock and the live poultry industry attracts considerable public attention. However, studies have not yet addressed its impact on public health in live poultry markets (LPMs). Herein, we investigated the prevalence and genomic epidemiology of blaNDM-positive bacteria in various niches, and explored the transmission patterns of blaNDM within LPMs. Samples were collected between 2019 and 2022 from two LPMs in China. blaNDM was most prevalent in wastewater (35/66, 53.03%). All vegetable samples were negative for blaNDM. blaNDM was mainly distributed among Escherichia coli (266/336, 79.17%), Klebsiella pneumoniae (62/336, 18.45%), and Acinetobacter baumannii (3/336, 0.89%). Some novel hosts, including Pseudomonas monteilii and Pseudomonas otitis, were also identified. Diverse variants blaNDM-1, blaNDM-5, blaNDM-9, blaNDM-13, and blaNDM-27 were identified. The blaNDM-positive E. coli ST2659 was dominant. blaNDM was found to coexist with mcr-1 (4/51, 7.84%). Horizontal gene transfer plays a vital role in blaNDM transmission within the LPMs. Some blaNDM-harboring clones transfer among animals and the environment through the food chain and close contact. More efforts are needed to curb the transmission trend of blaNDM among humans, animals, and the environment within LPMs.