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EnvZ/OmpR-dependent OmpF induction contributes to colistin-enhanced plasmid conjugation
Kai-Di Liu1, Fan-Yue Wang1, Wei-Hua Hao1
1College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, PR China.
Microbiological Research
|July 14, 2026
Summary
Sub-inhibitory colistin enhances bacterial plasmid transfer by inducing envelope stress and upregulating the OmpF porin. This antibiotic-induced stress facilitates horizontal gene transfer, accelerating antimicrobial resistance spread.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Horizontal gene transfer (HGT) via plasmids accelerates antimicrobial resistance (AMR).
- Mechanisms linking antibiotic-induced envelope stress to conjugation are poorly understood.
Purpose of the Study:
- Investigate how sub-inhibitory colistin affects plasmid-mediated HGT.
- Elucidate the molecular pathways involved in antibiotic-induced conjugation.
Main Methods:
- Conjugative transfer assays in E. coli with RP4 and resistance plasmids.
- Analysis of envelope perturbation (membrane permeability, LPS release).
- Gene expression analysis (OmpF, OmpC, EnvZ, OmpR) and genetic manipulation.
Main Results:
- Colistin significantly enhanced plasmid transfer without affecting growth, even in biofilms.
- Colistin induced envelope damage, increased OmpF expression, and upregulated the EnvZ/OmpR system.
- OmpF and the EnvZ/OmpR pathway were crucial for colistin-mediated HGT enhancement.
Conclusions:
- Colistin-induced envelope stress promotes HGT through the EnvZ/OmpR-OmpF pathway.
- This study reveals a molecular link between antibiotic stress and bacterial conjugation.
- Findings provide mechanistic insight into antibiotic-driven AMR dissemination.
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