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Updated: Oct 5, 2025
Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Comparative genomic analyses of Polymyxin-resistant Enterobacteriaceae strains from China
Zhien He1, Yongqiang Yang2,3,4, Wei Li1
1Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, China.
Background:
Mobile colistin resistance like gene (mcr-like gene) is a new type of polymyxin resistance gene that can be horizontally transferred in the Enterobacteriaceae. This has brought great challenges to the treatment of multidrug-resistant Escherichia coli and K. pneumoniae.
Results:
K. pneumoniae 16BU137 and E. coli 17MR471 were isolated from the bus and subway handrails in Guangzhou, China. K. pneumoniae 19PDR22 and KP20191015 were isolated from patients with urinary tract infection and severe pneumonia in Anhui, China. Sequence analysis indicated that the mcr-1.1 gene was present on the chromosome of E. coli 17MR471, and the gene was in the gene cassette containing pap2 and two copies of ISApl1.The mcr-1.1 was found in the putative IncX4 type plasmid p16BU137_mcr-1.1 of K. pneumoniae 16BU137, but ISApl1 was not found in its flanking sequence. Mcr-8 variants were found in the putative IncFIB/ IncFII plasmid pKP20191015_mcr-8 of K. pneumoniae KP20191015 and flanked by ISEcl1 and ISKpn26.
Conclusion:
This study provides timely information on Enterobacteriaceae bacteria carrying mcr-like genes, and provides a reference for studying the spread of mcr-1 in China and globally.
Insights
Mobile colistin resistance (mcr-like) genes were found in Enterobacteriaceae from environmental and clinical samples in China. This highlights the urgent need to track the spread of these challenging antimicrobial resistance genes.
Area of Science:
- Microbiology
- Antimicrobial Resistance
- Molecular Biology
Background:
- Mobile colistin resistance (mcr-like) genes pose significant challenges for treating multidrug-resistant Enterobacteriaceae.
- Horizontal gene transfer of mcr-like genes facilitates rapid spread within bacterial populations.
Purpose of the Study:
- To investigate the presence and genetic context of mcr-like genes in Enterobacteriaceae from China.
- To provide insights into the dissemination of mobile colistin resistance.
Main Methods:
- Isolation and identification of bacterial strains (K. pneumoniae, E. coli).
- Whole-genome sequencing and sequence analysis to identify mcr-like genes and their genetic environment.
- Plasmid analysis and characterization.
Main Results:
- The mcr-1.1 gene was identified on the chromosome of E. coli and within an IncX4 plasmid in K. pneumoniae.
- Mcr-8 variants were found on an IncFIB/IncFII plasmid in K. pneumoniae, associated with insertion sequences ISEcl1 and ISKpn26.
- Bacteria carrying mcr-like genes were isolated from both environmental (bus and subway handrails) and clinical (urinary tract infection, severe pneumonia) sources in China.
Conclusions:
- This study identifies Enterobacteriaceae carrying mcr-like genes in China, including environmental isolates.
- The findings offer valuable data for understanding the epidemiology and spread of mcr-1 and its variants globally.
- Provides a reference for future surveillance and control strategies against mobile colistin resistance.
