Microbiology Department, Hospital 103, Military Medical University, Hanoi, Vietnam.
National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
J Glob Antimicrob Resist. 2021 Dec;27:332-334. doi: 10.1016/j.jgar.2021.09.012. Epub 2021 Nov 18.
Mobile colistin resistance (mcr) genes are widely distributed around the world. To date, ten major variants of mcr genes are known (mcr-1 to mcr-10). However, only a few instances of Enterobacterales isolates harbouring mcr genes other than mcr-1 have been reported in Vietnam. The aim of this study was to investigate mcr-harbouring antimicrobial-resistant Enterobacterales isolates in Vietnam.
Two mcr-9-harbouring Enterobacter hormaechei clinical isolates (NIHE14-1904 and MH17-539M) were obtained from medical institutions in Hanoi, Vietnam, in 2014 and 2017, respectively. Their genomes and plasmid sequences were analysed by short-read and long-read sequencing. Subsequently, comparative sequence analysis of their mcr-9-carrying plasmids was performed.
Strains NIHE14-1904 and MH17-539M belonged to sequence types ST916 and ST66, respectively, according to the Enterobacter cloacae multilocus sequence typing (MLST) scheme. NIHE14-1904 and MH17-539M harboured the mcr-9 gene on similar IncHI2 plasmids, namely pNIHE14-1904-mcr9 (373.1 kb) and pMH17-539M-mcr9 (289.3 kb), respectively. These plasmids were also highly identical to widespread IncHI2 plasmids that are often associated with mcr genes.
For the first time, mcr-9-harbouring Enterobacterales isolates were detected in Vietnam, which carried mcr-9 on IncHI2 plasmids. The prevalence of such plasmids needs to be monitored in the future owing to their high dissemination.
移动多粘菌素耐药（mcr）基因在世界各地广泛分布。迄今为止，已知有 10 种主要的 mcr 基因变异体（mcr-1 至 mcr-10）。然而，在越南，除 mcr-1 以外的肠杆菌科分离株携带 mcr 基因的情况仅有少数报道。本研究旨在调查越南携带 mcr 基因的耐药肠杆菌科分离株。
2014 年和 2017 年，分别从越南河内的医疗机构获得 2 株携带 mcr-9 的肠杆菌霍氏菌临床分离株（NIHE14-1904 和 MH17-539M）。通过短读和长读测序分析它们的基因组和质粒序列。随后，对它们携带 mcr-9 的质粒进行了比较序列分析。
根据肠杆菌科多位点序列分型（MLST）方案，菌株 NIHE14-1904 和 MH17-539M 分别属于序列类型 ST916 和 ST66。NIHE14-1904 和 MH17-539M 携带 mcr-9 基因的质粒相似，分别为 pNIHE14-1904-mcr9（373.1 kb）和 pMH17-539M-mcr9（289.3 kb）。这些质粒与广泛传播的 IncHI2 质粒高度相似，而这些质粒通常与 mcr 基因相关。
首次在越南检测到携带 mcr-9 的肠杆菌科分离株，其携带 mcr-9 的质粒为 IncHI2 型。由于这些质粒传播广泛，未来需要对其流行情况进行监测。
