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Effect of combined oxidative and nitrosative stress on Neisseria meningitidis

K Dyet1, J Moir

  • 1Department of Biology (Area 10), University of York, Heslington, York YO10 5YW, UK.

Biochemical Society Transactions
|January 19, 2006
PubMed

Insights

Pathogens like Neisseria meningitidis use detoxification methods against immune reactive species. Nitric oxide (NO) affects hydrogen peroxide (H2O2) toxicity differently in bacteria, decreasing it in N. meningitidis but increasing it in E. coli.

Area of Science:

  • Microbiology
  • Immunology
  • Biochemistry

Background:

  • The human immune system produces reactive oxygen and nitrogen species to combat infections.
  • Pathogen survival often depends on their ability to detoxify these reactive species.
  • Neisseria meningitidis, a key cause of bacterial meningitis, requires detoxification mechanisms.

Purpose of the Study:

  • To investigate the toxicity of superoxide (O(2)(-)) and hydrogen peroxide (H(2)O(2)) generated by immune cells.
  • To determine the role of nitric oxide (NO) in modulating the toxicity of reactive oxygen species in bacterial pathogens.
  • To compare the effects of NO on reactive oxygen species toxicity in Neisseria meningitidis and Escherichia coli.

Main Methods:

  • Generated superoxide (O(2)(-)) using xanthine/xanthine oxidase (X/Xo) system.
  • Assessed hydrogen peroxide (H(2)O(2)) toxicity in the presence and absence of a nitric oxide (NO) donor (DEA-NONOate).
  • Compared the impact of NO on reactive oxygen species toxicity in Neisseria meningitidis and Escherichia coli.

Main Results:

  • Hydrogen peroxide (H(2)O(2)) was the primary toxic agent from the xanthine/xanthine oxidase (X/Xo) system.
  • Nitric oxide (NO) reduced the toxicity of H(2)O(2) towards Neisseria meningitidis.
  • Nitric oxide (NO) enhanced the toxicity of H(2)O(2) towards Escherichia coli.

Conclusions:

  • Nitric oxide (NO) plays a differential role in modulating reactive oxygen species toxicity in bacterial pathogens.
  • Understanding these interactions is crucial for developing strategies against bacterial meningitis and other infections.
  • Bacterial species exhibit distinct responses to immune-derived reactive nitrogen species.

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