Oral administration of live- or heat-killed Candida albicans worsened cecal ligation and puncture sepsis in a murine model possibly due to an increased serum (1→3)-β-D-glucan

PLoS One. 2017 Jul 27;12(7):e0181439. doi: 10.1371/journal.pone.0181439. eCollection 2017.

Abstract

Candida albicans is the most common fungus in the human intestinal microbiota but not in mice. To make a murine sepsis model more closely resemble human sepsis and to explore the role of intestinal C. albicans, in the absence of candidemia, in bacterial sepsis, live- or heat-killed C. albicans was orally administered to mice at 3h prior to cecal ligation and puncture (CLP). A higher mortality rate of CLP was demonstrated with Candida-administration (live- or heat-killed) prior to CLP. Fecal Candida presented only in experiments with live-Candida administration. Despite the absence of candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida-administration than CLP-controls (normal saline administration) at 6h and/or 18h post-CLP. Interestingly, fluconazole attenuated the fecal Candida burden and improved survival in mice with live-Candida administration, but not CLP-control. Microbiota analysis revealed increased Bacteroides spp. and reduced Lactobacillus spp. in feces after Candida administration. Additionally, synergy in the elicitation of cytokine production from bone marrow-derived macrophages, in vitro, was demonstrated by co-exposure to heat-killed E. coli and BG. In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis-severity, perhaps through enhanced cytokine elicitation induced by synergistic responses to molecules from gut-derived bacteria and fungi. Conversely, reducing intestinal fungal burdens decreased serum BG and attenuated sepsis in our model.

MeSH terms

  • Administration, Oral
  • Animals
  • Blood Bactericidal Activity
  • Candida albicans / physiology*
  • Cecum / pathology*
  • Cytokines / blood
  • Disease Models, Animal
  • Escherichia coli / metabolism
  • Feces / microbiology
  • Gastrointestinal Microbiome
  • Ligation
  • Macrophages / metabolism
  • Male
  • Mice, Inbred ICR
  • Punctures
  • Sepsis / blood*
  • Sepsis / microbiology*
  • Survival Analysis
  • Time Factors
  • beta-Glucans / blood*

Substances

  • Cytokines
  • beta-Glucans

Grants and funding

This study was funded by Ratchadapiseksompotch Fund (RA60/035), Faculty of Medicine, Grant for Development of New Faculty Staff Chulalongkorn University and Thailand Research fund (RSA60). WP was supported by Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program (PHD/0316/2552). BG assays were partly supported by Associates of Cape Cod, Inc. The Associates of Cape Cod, Inc., provided support in the form of salaries for authors [MF], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.