Detection and characterization of a clinical Escherichia coli ST3204 strain coproducing NDM-16 and MCR-1

作者：Li, Xi; Mu, Xinli; Zhang, Ping; Zhao, Dongdong; Ji, Jingshu; Quan, Jingjing; Zhu, Yongze^*; Yu, Yunsong^*

来源：Infection and Drug Resistance, 2018, 11: 1189-1195.

DOI：10.2147/IDR.S175041

• E. coli
• mcr-1
• NDM-16
• CRE
• colistin resistance
• extensively drug-resistant bacteria

Objectives: A plasmid-mediated colistin resistance gene, mcr-1, has been reported worldwide and has caused concern regarding a major therapeutic challenge. Alarmingly, mcr-1 has spread into clinical carbapenem-resistant Enterobacteriaceae isolates, resulting in extensively drug-resistant and even pan drug-resistant isolates that can cause untreatable infections. In this study, we report isolation of an extensively drug-resistant Escherichia coli strain EC1188 that coproduces NDM-16 and MCR-1 from a urine sample taken from a patient with craniocerebral injury. @@@ Materials and methods: E. coli strain EC1188 was identified and subjected to genotyping, susceptibility testing and conjugation experiments. The genetic locations of bla(NDM-16) and mcr-1 were established with southern blot hybridization. The complete genome sequence of this strain was obtained and the genetic characteristics of the mcr-1-and bla(NDM-16)-harboring plasmids were analyzed. In addition, comparative genetic analyses of mcr-1 and bla(NDM-16) with closely related plasmids were also carried out. @@@ Results: Whole-genome sequencing revealed that strain EC1188 possess various resistance genes and virulence genes. S1-pulsed-field gel electrophoresis and southern blot suggested that the bla(NDM-16) and mcr-1 genes were located on an similar to 65 kb plasmid and an similar to 80 kb plasmid, respectively. Moreover, the two genes could successfully transfer their resistance phenotype to E. coli strain C600. Sequence analysis showed that these two plasmids possessed high sequence similarity to previously reported bla(NDM-5)-harboring and mcr-1-harboring plasmids in China. @@@ Conclusion: To the best of our knowledge, this is the first report to isolate an E. coli strain that coproduces NDM-16 and MCR-1. In addition, we characterized the bla(NDM-16)-harboring plasmid for the first time. Our study further emphasizes that the co-occurrence of the two prevalent transferrable resistance plasmids in a single isolate is highly significant because infections caused by MCR-1-producing carbapenem-resistant Enterobacteriaceae isolates are increasing each year. It is imperative to perform active surveillance to prevent further dissemination of MCR-1-producing CRE isolates.

• 出版日期2018
• 单位浙江省人民医院; 浙江大学