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[EFFECT OF OSMOTIC AND OXIDATIVE STRESS ON STRAINS OF GENOVARIANTS OF VIBRIO CHOLERAE EL TOR BIOVAR]
Zhurnal Mikrobiologii, Epidemiologii I Immunobiologii
|March 9, 2016
Summary
Genovariants of Vibrio cholerae El Tor biovar exhibit enhanced resistance to osmotic and oxidative stress compared to typical strains. This increased survivability is likely due to an extra exopolysaccharide layer and potential loss of mobile genetic elements.
Area of Science:
- Microbiology
- Environmental Science
- Genetics
Background:
- Vibrio cholerae El Tor biovar causes cholera outbreaks.
- Understanding strain variations is crucial for public health.
- Environmental stressors impact bacterial survival.
Purpose of the Study:
- To investigate the impact of osmotic and oxidative stress on Vibrio cholerae El Tor biovar genovariants.
- To compare the stress resistance of genovariants versus typical strains.
- To analyze changes in phenotypic and genetic properties under stress.
Main Methods:
- Utilized 22 strains of V. cholerae El Tor biovar.
- Assessed phenotypic properties in LB medium with additives.
- Examined cell surface structures using scanning probe microscopy.
- Performed PCR analysis with specific primers.
Main Results:
- Genovariants showed significantly higher survival rates (3.0-25.0x for salt, 4.3-7.6x for hydrogen peroxide) than typical strains.
- Increased salt resistance in genovariants linked to earlier production of an exopolysaccharide layer.
- Osmotic stress caused reversible mobility reduction in genovariants.
- Both stresses led to the loss of mobile genetic elements in genovariants.
Conclusions:
- V. cholerae El Tor biovar genovariants are more resistant to osmotic and oxidative stress than typical strains.
- This enhanced resistance likely contributes to their greater survival in environmental and host settings.
- Genovariants responsible for Russian outbreaks (1993-2001) displayed this heightened resistance compared to earlier strains (1970-1990).
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