Delftia acidovorans secretes substances that inhibit the growth of Staphylococcus epidermidis through TCA cycle-triggered ROS production

PLoS One. 2021 Jul 2;16(7):e0253618. doi: 10.1371/journal.pone.0253618. eCollection 2021.

Abstract

The proportion of Staphylococcus aureus in the skin microbiome is associated with the severity of inflammation in the skin disease atopic dermatitis. Staphylococcus epidermidis, a commensal skin bacterium, inhibits the growth of S. aureus in the skin. Therefore, the balance between S. epidermidis and S. aureus in the skin microbiome is important for maintaining healthy skin. In the present study, we demonstrated that the heat-treated culture supernatant of Delftia acidovorans, a member of the skin microbiome, inhibits the growth of S. epidermidis, but not that of S. aureus. Comprehensive gene expression analysis by RNA sequencing revealed that culture supernatant of D. acidovorans increased the expression of genes related to glycolysis and the tricarboxylic acid cycle (TCA) cycle in S. epidermidis. Malonate, an inhibitor of succinate dehydrogenase in the TCA cycle, suppressed the inhibitory effect of the heat-treated culture supernatant of D. acidovorans on the growth of S. epidermidis. Reactive oxygen species production in S. epidermidis was induced by the heat-treated culture supernatant of D. acidovorans and suppressed by malonate. Further, the inhibitory effect of the heat-treated culture supernatant of D. acidovorans on the growth of S. epidermidis was suppressed by N-acetyl-L-cysteine, a free radical scavenger. These findings suggest that heat-resistant substances secreted by D. acidovorans inhibit the growth of S. epidermidis by inducing the production of reactive oxygen species via the TCA cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology
  • Bacterial Proteins / metabolism
  • Citric Acid Cycle / immunology
  • Delftia acidovorans / genetics
  • Delftia acidovorans / immunology*
  • Delftia acidovorans / metabolism
  • Dermatitis, Atopic / immunology*
  • Dermatitis, Atopic / microbiology
  • Dermatitis, Atopic / pathology
  • Gene Expression Regulation, Bacterial / immunology
  • Humans
  • Microbiota / immunology
  • RNA-Seq
  • Reactive Oxygen Species / metabolism
  • Skin / immunology
  • Skin / microbiology*
  • Skin / pathology
  • Staphylococcal Infections / immunology*
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / pathology
  • Staphylococcus aureus / immunology
  • Staphylococcus aureus / isolation & purification
  • Staphylococcus epidermidis / immunology
  • Staphylococcus epidermidis / isolation & purification*

Substances

  • Bacterial Proteins
  • Reactive Oxygen Species

Grants and funding

This study was supported by the Japan Society for the Promotion of Science, JSPS, https://www.jsps.go.jp/english/index.html, (grant number JP20K07208 to O.C., JP16K08384, and JP19K07176 to T.S.). The funders did not play any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.