Abstract
Biofilm formation involving profuse hyphal growth is a major characteristic of Candida spp. and confers higher antifungal resistance than its planktonic mode of growth. We investigated the antifungal susceptibility of Candida albicans and its hyphal mutants (Δefg1/efg1, Δcph1/cph1 and ΔΔcph1/cph1 efg1/efg1) to commonly used antifungals during planktonic, adhesion and biofilm modes of growth. The minimum inhibitory concentration (MIC) of each antifungal agent was determined for a lower inoculum (1 × 103 cells/mL) and higher inoculum (1 × 107 cells/mL) of planktonic Candida. Furthermore, MICs of C. albicans biofilms and adhesion modes of growth were determined with a standard XTT assay. Candida albicans in adhesion and biofilm modes of growth, but not in planktonic mode, were resistant to all five antifungal agents tested. Although Δefg1/efg1 and ΔΔcph1/cph1 efg1/efg1 mutants formed less biofilm than wild-type C. albicans SC5314, they were similarly resistant to caspofungin. However, these mutants were more sensitive to amphotericin B and nystatin than the wild-type. Adhesion per se confers increased resistance to antifungal agents, which is further pronounced in the biofilm mode of Candida. Filamentation does not appear to be a major determinant of the antifungal resistance in Candida biofilms.
Original language | English |
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Pages (from-to) | 333-339 |
Number of pages | 7 |
Journal | International Journal of Antimicrobial Agents |
Volume | 34 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2009 Oct |
Externally published | Yes |
Keywords
- Antifungal susceptibility
- Biofilm
- Candida
- Hyphal mutants
ASJC Scopus subject areas
- Microbiology (medical)
- Infectious Diseases
- Pharmacology (medical)