The emergence of carbapenem-resistant Enterobacteriaceae poses a significant threat to public health worldwide. Here, we reported a multidrug-resistant Escherichia coli strain with two different bla NDM- 5-carrying plasmids from China. Illumina short-read and MinION long-read whole genome sequencing were performed. Genomic analysis found that one bla NDM- 5 gene together with mphA was located on a 55-kb IncX3 plasmid, while the other bla NDM- 5 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 bla NDM- 5 than those with both plasmids or the IncFII plasmid. Two other β-lactamase genes (bla CTX-M- 15 and bla OXA- 1) were also detected on another 160-kb IncF plasmid. This is the first report of coexistence of two bla NDM- 5-carrying plasmids in a single bacterial isolate, highlighting the genetic complexity of NDM-5 carbapenemase circulation, and the urgent need for continued active surveillance.
Keywords: Escherichia coli; Illumina short-read sequencing; MinION long-read sequencing; coexistence of two blaNDM–5 genes; transferability.
Copyright © 2020 Yang, Lin, Lu, Xue, Ma, Guo, Wang, Li, Du, Qi, Li and Song.