[Source: PLoS ONE, full text: (LINK). Abstract, edited.]
Identification and Characterization of the First Escherichia coli Strain Carrying NDM-1 Gene in China

by Zhiyuan Liu, Wei Li, Jie Wang, Jian Pan, Shipeng Sun, Yanhua Yu, Bing Zhao, Yuzhi Ma, Tingju Zhang, Jie Qi, Guijian Liu, Fengmin Lu


New Delhi metallo-β-lactamase-1 (NDM-1), an acquired class B carbapenemase, is a significant clinical threat due to its extended hydrolysis of β-lactams including carbapenems. In this study, we identified the first confirmed clinical isolate of Escherichia coli BJ01 harboring bla<SUB>NDM-1</SUB> in China. The isolate is highly resistant to all tested antimicrobials except polymyxin. bla<SUB>NDM-1</SUB>, bla<SUB>CTX-M-57</SUB>, and bla<SUB>TEM-1</SUB> were identified in the isolate. bla<SUB>NDM-1</SUB> was transferable to E. coli EC600 and DH5α in both plasmid conjugation experiments and plasmid transformation tests. BJ01 was identified as a new sequence type, ST224, by multilocus sequence typing. Analysis of genetic environment shows complex transposon-like structures surrounding the bla<SUB>NDM-1</SUB> gene. Genetic analysis revealed that the region flanking bla<SUB>NDM-1</SUB> was very similar to previously identified NDM-positive Acinetobacter spp. isolated in China. The findings of this study raise attention to the emergence and spread of NDM-1-carrying Enterobacteriaceae in China.