Effect of fluconazole on agar invasion by Candida albicans

Subinhibitory concentrations of azoles are known to inhibit hyphal branching of Candida albicans in liquid media. This study showed that subinhibitory concentrations of fluconazole also inhibit agar invasion by C. albicans in YPD solid medium. Agar invasion was markedly inhibited in two C. albicans strains that were resistant to fluconazole. This suggests that the degree to which fluconazole inhibits agar invasion by C. albicans hyphae could serve as a marker of susceptibility to azoles.