H 2 S, a Bacterial Defense Mechanism against the Host Immune Response

Infect Immun. 2018 Dec 19;87(1):e00272-18. doi: 10.1128/IAI.00272-18. Print 2019 Jan.

Abstract

The biological mediator hydrogen sulfide (H2S) is produced by bacteria and has been shown to be cytoprotective against oxidative stress and to increase the sensitivity of various bacteria to a range of antibiotic drugs. Here we evaluated whether bacterial H2S provides resistance against the immune response, using two bacterial species that are common sources of nosocomial infections, Escherichia coli and Staphylococcus aureus Elevations in H2S levels increased the resistance of both species to immune-mediated killing. Clearances of infections with wild-type and genetically H2S-deficient E. coli and S. aureus were compared in vitro and in mouse models of abdominal sepsis and burn wound infection. Also, inhibitors of H2S-producing enzymes were used to assess bacterial killing by leukocytes. We found that inhibition of bacterial H2S production can increase the susceptibility of both bacterial species to rapid killing by immune cells and can improve bacterial clearance after severe burn, an injury that increases susceptibility to opportunistic infections. These findings support the role of H2S as a bacterial defense mechanism against the host response and implicate bacterial H2S inhibition as a potential therapeutic intervention in the prevention or treatment of infections.

Keywords: antibiotic resistance; burn; hydrogen sulfide; opportunistic infections.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Escherichia coli / growth & development*
  • Escherichia coli / immunology
  • Escherichia coli / metabolism
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / pathology*
  • Host-Pathogen Interactions*
  • Hydrogen Sulfide / metabolism*
  • Immune Evasion
  • Leukocytes / immunology
  • Male
  • Mice, Inbred BALB C
  • Microbial Viability
  • Sepsis / microbiology
  • Sepsis / pathology
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / pathology*
  • Staphylococcus aureus / growth & development*
  • Staphylococcus aureus / immunology
  • Staphylococcus aureus / metabolism
  • Wound Infection / microbiology
  • Wound Infection / pathology

Substances

  • Hydrogen Sulfide