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Updated: Jul 7, 2026

Studying Oxidative Stress Caused by the Mitis Group Streptococci in Caenorhabditis elegans
Published on: March 23, 2019
Effect of exposure to hydrogen peroxide on the virulence of Escherichia coli
1Department of Microbiology, Kasturba Medical College, Mangalore - 575 001, Karnataka, India.
Purpose:
To eliminate pathogenic bacteria, the host presents conditions that are stressful for bacteria. Oxidative stress arises when the concentration of pro-oxidants like hydrogen peroxide (H2O2 ) and superoxide anion increases to a level over the basal defence capacity of the cell. In the present study, we studied the effect of oxidative stress on the production of certain virulence factors by Escherichia coli .
Methods:
E. coli was exposed to oxidative stress by growing in the presence of different concentrations of H2O2 . The effect of oxidative stress on the expression of surface hydrophobicity, adherence, haemolysin production, serum resistance and phagocytosis was studied.
Results:
Oxidative stress caused a significant decrease in the expression of all the virulence factors of E. coli .
Conclusions:
Synthesis of virulence factors can be significantly altered by oxidative stress and such changes may affect the pathogenicity of E. coli.
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