Carriage of the mcr-9 and mcr-10 genes in clinical strains of the Enterobacter cloacae complex in China : a prevalence and molecular epidemiology study

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Hongwei Zhou
  • Siheng Wang
  • Yuchen Wu
  • Ning Dong
  • Xiaoyang Ju
  • Chang Cai
  • Ruichao Li
  • Yan Li
  • Congcong Liu
  • Jiayue Lu
  • Edward Wai-Chi Chan
  • Zhangqi Shen

Detail(s)

Original languageEnglish
Article number106645
Journal / PublicationInternational Journal of Antimicrobial Agents
Volume60
Issue number4
Online published28 Jul 2022
Publication statusPublished - Oct 2022

Abstract

Objectives: Enterobacter cloacae complex (ECC) is among the most common carbapenem-resistant Enterobacteriaceae (CRE) in China. The emergence of mcr has rendered CRE strains resistant to the last-line antibiotic colistin. This study investigated the prevalence of mcr-9 and mcr-10 in carbapenem-resistant ECC (CRECC) and carbapenem-susceptible ECC (CSECC) in China.

Methods: The CRECC and CSECC strains were collected from different regions of China. Antimicrobial susceptibility tests, conjugation experiments, whole genome sequencing, bioinformatic analysis, and quantitative RT-PCR were performed to understand the mechanisms of resistance and transmission of mcr in ECC.

Results: A total of 534 ECC were collected, among which 57 (10.7%) and 23 (4.3%) were positive for mcr-9 and mcr-10, respectively. The prevalence of mcr-9 in CRECC was significantly higher than that in CSECC (31.8% vs. 3.7%; P < 0.001), while the prevalence of mcr-10 in CRECC was significantly lower (0.8% vs. 5.5%; P < 0.05). Most mcr-9-positive strains (n = 45, 78.9%) exhibited multidrug-resistant phenotype, and four (17.4%) of the mcr-10-positive strains exhibited multi-drug resistance. Coexistence of mcr and carbapenemase genes was commonly observed, including 41 (71.9%) mcr-9-positive strains and one (4.3%) mcr-10-positive strain, and the possibility of co-transfer was confirmed by conjugation experiments. The mcr-positive ECC were highly diverse, while most mcr genes were plasmid-encoded, indicating the important role of plasmids in the transmission of mcr in ECC. Furthermore, the expression of mcr-9 was increased after induction by colistin.

Conclusions: The widespread mcr genes and co-transfer with carbapenemase genes among ECC strains pose an urgent threat to public health.

Research Area(s)

  • mcr-9, mcr-10, Enterobacter cloacae complex, Colistin, Carbapenem-resistant Enterobacteriaceae, Epidemiology

Citation Format(s)

Carriage of the mcr-9 and mcr-10 genes in clinical strains of the Enterobacter cloacae complex in China : a prevalence and molecular epidemiology study. / Zhou, Hongwei; Wang, Siheng; Wu, Yuchen; Dong, Ning; Ju, Xiaoyang; Cai, Chang; Li, Ruichao; Li, Yan; Liu, Congcong; Lu, Jiayue; Chan, Edward Wai-Chi; Chen, Sheng; Zhang, Rong; Shen, Zhangqi.

In: International Journal of Antimicrobial Agents, Vol. 60, No. 4, 106645, 10.2022.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review