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Streptococcal co-infection augments Candida pathogenicity by amplifying the mucosal inflammatory response
1Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT, USA.
Cellular Microbiology
|October 2, 2013
Summary
Mitis-group streptococci, like Streptococcus oralis, enhance Candida albicans virulence in oral infections. This synergy, involving TLR2 signaling, increases inflammation and fungal spread to organs.
Area of Science:
- Microbiology
- Immunology
- Oral Health
Background:
- Mitis-group streptococci are common oral bacteria that can increase the virulence of bacterial biofilms.
- Candida albicans is an opportunistic fungal pathogen causing oral thrush.
Purpose of the Study:
- To investigate if Streptococcus oralis enhances Candida albicans virulence in oral mucosal infections.
- To explore the mechanisms behind this potential pathogenic synergy.
Main Methods:
- A novel murine oral mucosal co-infection model was used.
- Whole mouse genome tongue microarray analysis identified upregulated genes.
- Experiments were conducted in Toll-like receptor 2 knockout (TLR2(-/-)) mice.
Main Results:
- Streptococcus oralis colonization and Candida albicans-induced oral thrush lesions were increased in co-infected mice.
- Streptococcus oralis promoted the dissemination of Candida albicans to deep organs.
- Co-infection led to upregulated genes in neutrophilic response, chemotaxis, and inflammation, dependent on TLR2 signaling.
Conclusions:
- A previously unrecognized pathogenic synergy exists between oral commensal bacteria and Candida albicans.
- Mucosal commensal bacteria can modify the virulence of opportunistic fungal pathogens.
- TLR2 signaling plays a crucial role in the inflammatory response during this co-infection.
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