Abstract
The fungus Candida albicans colonizes oral cavity surfaces and is carried by up to 60% of human populations. Biofilm development by C. albicans may be modulated by oral streptococci, such as Streptococcus gordonii, S. oralis or S. mutans,
so as to augment pathogenicity. In this study we sought to determine if
the cell wall-associated secreted aspartyl proteinase Sap9 was
necessary for hyphal adhesin functions associated with biofilm community
development. A sap9Δ mutant of C. albicans SC5314
formed biofilms that were flatter, and contained fewer blastospores and
more hyphal filaments than the parent strain. This phenotypic difference
was accentuated under flow (shear) conditions and in the presence of S. gordonii. Dual-species biofilms of C. albicans sap9Δ with S. oralis, S. sanguinis, S. parasanguinis, S. mutans and Enterococcus faecalis all contained more matted hyphae and more bacteria bound to substratum compared to C. albicans wild type. sap9Δ mutant hyphae showed significantly increased cell surface hydrophobicity, ∼25% increased levels of binding C. albicans
cell wall protein Als3, and reduced interaction with Eap1, implicating
Sap9 in fungal cell–cell recognition. These observations suggest that
Sap9 is associated with protein–receptor interactions between fungal
cells, and with interkingdom communication in the formation of
polymicrobial biofilm communities.
Original language | English |
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Article number | ftw005 |
Number of pages | 12 |
Journal | Pathogens and Disease |
Volume | 74 |
Issue number | 3 |
Early online date | 14 Jan 2016 |
DOIs | |
Publication status | Published - Apr 2016 |
Keywords
- microbial interactions
- mixed species communities
- Streptococcus gordonii
- Streptococcus mutans
- oral cavity biofilms