AUTHOR=Liu Yi-Yun , Li Tong , Yue Huiying , Yue Chao , Lu Litao , Chen Junqiang , Deng Haotian , Gao Xun , Liu Jian-Hua 

TITLE=Occurrence and characterization of NDM-5-producing Escherichia coli from retail eggs

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1281838

DOI=10.3389/fmicb.2023.1281838

ISSN=1664-302X

ABSTRACT=<p>The New Delhi Metallo-β-lactamase (NDM) producing Enterobacterales has been detected from diverse sources but has rarely been reported in retail eggs. In this study, 144 eggshell and 96 egg content samples were collected in 2022 from Guangdong province and were screened for NDM-producing strains. Four <italic>Escherichia coli</italic> strains (ST3014, ST10, ST1485, and ST14747) recovered from two (1.39%, 2 of 144) eggshells and two (2.08%, 2 of 96) egg content samples were identified as <italic>bla</italic><sub>NDM−5</sub>-positive strains. Oxford Nanopore MinION sequencing and conjugation assays revealed that the <italic>bla</italic><sub>NDM−5</sub> gene was carried by IncX3 (<italic>n</italic> = 1), IncI1 (<italic>n</italic> = 1), and IncHI2 (<italic>n</italic> = 2). The IncI1-plasmid-carrying <italic>bla</italic><sub>NDM−5</sub> displayed high homology with one plasmid pEC6563-NDM5 from the human clinic, while the IncHI2 plasmid harboring <italic>bla</italic><sub>NDM−5</sub> shared highly similar structures with plasmids of animal origin. To the best of our knowledge, this is the first report on the identification of <italic>bla</italic><sub>NDM−5</sub>-positive bacteria in retail eggs. NDM-producing <italic>E. coli</italic> could be transmitted to humans by the consumption of eggs or direct contact, which could pose a potential threat to human health.</p>