TY - JOUR
T1 - Effect of filamentation and mode of growth on antifungal susceptibility of Candida albicans
AU - Watamoto, T.
AU - Samaranayake, L. P.
AU - Jayatilake, J. A.M.S.
AU - Egusa, H.
AU - Yatani, H.
AU - Seneviratne, C. J.
N1 - Funding Information:
Funding : This work was supported by the Hong Kong Research Grants Council (RGC No. HKU 7624/06M).
PY - 2009/10
Y1 - 2009/10
N2 - 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.
AB - 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.
KW - Antifungal susceptibility
KW - Biofilm
KW - Candida
KW - Hyphal mutants
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U2 - 10.1016/j.ijantimicag.2009.03.008
DO - 10.1016/j.ijantimicag.2009.03.008
M3 - Article
C2 - 19376687
AN - SCOPUS:67651229521
VL - 34
SP - 333
EP - 339
JO - International Journal of Antimicrobial Agents
JF - International Journal of Antimicrobial Agents
SN - 0924-8579
IS - 4
ER -
