AUTHOR=Yang Lang , Lin Yanfeng , Lu Lanfen , Xue Mei , Ma Hui , Guo Xuguang , Wang Kaiying , Li Peihan , Du Xinying , Qi Kezong , Li Peng , Song Hongbin 

TITLE=Coexistence of Two blaNDM–5 Genes Carried on IncX3 and IncFII Plasmids in an Escherichia coli Isolate Revealed by Illumina and Nanopore Sequencing

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00195

DOI=10.3389/fmicb.2020.00195

ISSN=1664-302X

ABSTRACT=<p>The emergence of carbapenem-resistant <italic>Enterobacteriaceae</italic> poses a significant threat to public health worldwide. Here, we reported a multidrug-resistant <italic>Escherichia coli</italic> strain with two different <italic>bla</italic><sub>NDM–</sub><sub>5</sub>-carrying plasmids from China. Illumina short-read and MinION long-read whole genome sequencing were performed. Genomic analysis found that one <italic>bla</italic><sub>NDM–</sub><sub>5</sub> gene together with <italic>mphA</italic> was located on a 55-kb IncX3 plasmid, while the other <italic>bla</italic><sub>NDM–</sub><sub>5</sub> gene was on a novel 68-kb IncFII plasmid. Susceptibility testing and quantitative reverse transcription PCR results further indicated that the transconjugants with the IncX3 plasmid exhibited higher-level carbapenem resistance and expression of <italic>bla</italic><sub>NDM–</sub><sub>5</sub> than those with both plasmids or the IncFII plasmid. Two other β-lactamase genes (<italic>bla</italic><sub><italic>CTX–M–</italic></sub><sub>15</sub> and <italic>bla</italic><sub>OXA–</sub><sub>1</sub>) were also detected on another 160-kb IncF plasmid. This is the first report of coexistence of two <italic>bla</italic><sub>NDM–</sub><sub>5</sub>-carrying plasmids in a single bacterial isolate, highlighting the genetic complexity of NDM-5 carbapenemase circulation, and the urgent need for continued active surveillance.</p>