Related Experiment Video
Updated: Jun 12, 2025
The Nematode Caenorhabditis Elegans - A Versatile In Vivo Model to Study Host-microbe Interactions
Published on: October 18, 2017
Synergistic cross-kingdom host cell damage between Candida albicans and Enterococcus faecalis
Abstract:
The fungus Candida albicans and the Gram-positive bacterium Enterococcus faecalis share mucosal niches in the human body. As opportunistic pathogens, both are found to expand population size during dysbiosis, and can cause severe systemic infections in susceptible individuals. Here, we show that the presence of C. albicans results in increased host cell damage by E. faecalis . Furthermore, E. faecalis aggravates oropharyngeal candidiasis in mice. Increased damage is mediated by enterococcal cytolysin, and involves both physical interaction and altered glucose availability. Physical interaction promotes accumulation of bacteria on host cells, facilitating contact of cytolysin with host cells. Glucose depletion by the metabolic activity of the fungus sensitized host cells to cytolysin. This work illustrates how a complex interplay between fungi and bacteria can result in detrimental consequences for the host.
Insights
The fungus Candida albicans and bacterium Enterococcus faecalis interact, increasing host cell damage. This fungal-bacterial synergy worsens infections, highlighting complex microbial interplay in disease.
Area of Science:
- Microbiology
- Pathogenesis
- Host-microbe interactions
Background:
- Candida albicans and Enterococcus faecalis are opportunistic pathogens sharing mucosal sites.
- Both microbes can cause severe infections, especially during dysbiosis.
- Understanding their interactions is crucial for managing polymicrobial diseases.
Purpose of the Study:
- To investigate the impact of Candida albicans presence on Enterococcus faecalis-mediated host cell damage.
- To elucidate the mechanisms underlying the synergistic pathogenicity of these two microbes.
- To determine the role of enterococcal cytolysin in the aggravated oropharyngeal candidiasis model.
Main Methods:
- Co-culture experiments to assess host cell damage.
- Murine model of oropharyngeal candidiasis to evaluate disease severity.
- Analysis of physical interactions and glucose availability.
- Assessment of enterococcal cytolysin activity.
Main Results:
- Candida albicans presence significantly increased host cell damage caused by Enterococcus faecalis.
- Enterococcus faecalis aggravated oropharyngeal candidiasis in a mouse model.
- Enterococcal cytolysin, physical interaction, and fungal-mediated glucose depletion were key factors.
- Physical contact facilitated cytolysin delivery, while glucose depletion sensitized host cells.
Conclusions:
- Fungal-bacterial interactions can lead to enhanced pathogenicity and host damage.
- Enterococcus faecalis cytolysin plays a critical role in the synergistic damage.
- Altered nutrient availability and direct physical contact mediate this detrimental interplay.
