Li Xi, Mu Xinli, Zhang Ping, Zhao Dongdong, Ji Jingshu, Quan Jingjing, Zhu Yongze, Yu Yunsong
Centre of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical college, Hangzhou, Zhejiang 310014, China,
Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China,
Infect Drug Resist. 2018 Aug 15;11:1189-1195. doi: 10.2147/IDR.S175041. eCollection 2018.
A plasmid-mediated colistin resistance gene, , has been reported worldwide and has caused concern regarding a major therapeutic challenge. Alarmingly, 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 strain EC1188 that coproduces NDM-16 and MCR-1 from a urine sample taken from a patient with craniocerebral injury.
strain EC1188 was identified and subjected to genotyping, susceptibility testing and conjugation experiments. The genetic locations of and were established with southern blot hybridization. The complete genome sequence of this strain was obtained and the genetic characteristics of the - and -harboring plasmids were analyzed. In addition, comparative genetic analyses of and with closely related plasmids were also carried out.
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 and genes were located on an ~65 kb plasmid and an ~80 kb plasmid, respectively. Moreover, the two genes could successfully transfer their resistance phenotype to strain C600. Sequence analysis showed that these two plasmids possessed high sequence similarity to previously reported -harboring and -harboring plasmids in China.
To the best of our knowledge, this is the first report to isolate an strain that coproduces NDM-16 and MCR-1. In addition, we characterized the -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.
一种质粒介导的黏菌素耐药基因，已在全球范围内被报道，并引发了对一项重大治疗挑战的关注。令人担忧的是，已传播到临床耐碳青霉烯类肠杆菌科分离株中，导致产生广泛耐药甚至泛耐药的分离株，可引起无法治疗的感染。在本研究中，我们报告了从一名颅脑损伤患者的尿液样本中分离出一株同时产生NDM-16和MCR-1的广泛耐药菌株EC1188。
对菌株EC1188进行鉴定，并进行基因分型、药敏试验和接合实验。通过Southern杂交确定和的基因位置。获得该菌株的全基因组序列，并分析携带和的质粒的遗传特征。此外，还对和与密切相关质粒进行了比较遗传分析。
全基因组测序显示菌株EC1188拥有多种耐药基因和毒力基因。S1脉冲场凝胶电泳和Southern杂交表明，和基因分别位于一个约65 kb的质粒和一个约80 kb的质粒上。此外，这两个基因可成功将其耐药表型转移至菌株C600。序列分析表明，这两个质粒与中国先前报道的携带和的质粒具有高度序列相似性。
据我们所知，这是首次报道分离出一株同时产生NDM-16和MCR-1的菌株。此外，我们首次对携带的质粒进行了表征。我们的研究进一步强调，单个分离株中两种常见的可转移耐药质粒同时出现具有高度重要性，因为每年由产生MCR-1的耐碳青霉烯类肠杆菌科分离株引起的感染都在增加。必须进行主动监测以防止产生MCR-1的耐碳青霉烯类肠杆菌科分离株的进一步传播。
