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The Native Plasmid pML21 Plays a Role in Stress Tolerance in Enterococcus faecalis ML21, as Analyzed by Plasmid
Fang-Lei Zuo1, Li-Li Chen1, Zhu Zeng1
1Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road Haidian District, Beijing, 100083, People's Republic of China.
Abstract:
To investigate the role of the native plasmid pML21 in Enterococcus faecalis ML21's response to abiotic stresses, the plasmid pML21 was cured based on the principle of plasmid incompatibility and segregational instability, generating E. faecalis mutant strain ML0. The mutant and the wild strains were exposed to abiotic stresses: bile salts, low pH, H2O2, ethanol, heat, and NaCl, and their survival rate was measured. We found that curing of pML21 lead to reduced tolerance to stress in E. faecalis ML0, especially oxidative and osmotic stress. Complementation analysis suggested that the genes from pML21 played different role in stress tolerance. The result indicated that pML21 plays a role in E. faecalis ML21's response to abiotic stresses.
Insights
The native plasmid pML21 enhances Enterococcus faecalis ML21 survival against abiotic stresses, particularly oxidative and osmotic challenges. Removing this plasmid significantly reduces the bacterium
Area of Science:
- Microbiology
- Bacterial Genetics
- Stress Response
Background:
- Enterococcus faecalis is an opportunistic pathogen.
- Native plasmids can influence bacterial adaptation and virulence.
- The role of plasmid pML21 in E. faecalis ML21 stress response is unknown.
Purpose of the Study:
- To investigate the function of native plasmid pML21 in Enterococcus faecalis ML21.
- To determine the role of pML21 in the bacterium's response to various abiotic stresses.
Main Methods:
- Plasmid curing was performed using plasmid incompatibility and segregational instability.
- E. faecalis mutant (ML0) and wild-type strains were exposed to bile salts, low pH, H2O2, ethanol, heat, and NaCl.
- Survival rates were measured to assess stress tolerance.
Main Results:
- Curing of pML21 resulted in reduced stress tolerance in E. faecalis ML0.
- The most significant reductions in tolerance were observed under oxidative and osmotic stress conditions.
- Complementation analysis indicated that genes on pML21 contribute differentially to stress tolerance.
Conclusions:
- The native plasmid pML21 plays a significant role in the adaptation of Enterococcus faecalis ML21 to abiotic stresses.
- Specific genes on pML21 are involved in conferring tolerance to oxidative and osmotic stress.
- Understanding plasmid-mediated stress response is crucial for controlling E. faecalis infections.
