Systemic candidiasis, which is mainly caused by Candida albicans,
is a serious acute fungal infection in the clinical setting.
In a previous study, we reported that compound 22h (designated
as AB-22 in this study), a vinyl sulfate compound, is a
fast-acting fungicidal agent against a broad spectrum of fungal
pathogens. In this study, we aimed to further analyze the
in vitro and in vivo efficacy of AB-22 against filamentation,
biofilm formation, and virulence of C. albicans. Under in vitro
hyphal growth-inducing condition, AB-22 effectively inhibited
germ tube formation and hyphal growth, which are required
for the initiation of biofilm formation. Indeed, AB-22
significantly suppressed C. albicans biofilm formation in a
dose-dependent manner. Moreover, AB-22 treatment inhibited
the normal induction of ALS3, HWP1, and ECE1, which
are all required for hyphal transition in C. albicans. Furthermore,
AB-22 treatment increased the survival of mice systemically
infected with C. albicans. In conclusion, in addition
to its fungicidal activity, AB-22 inhibits filamentation and
biofilm formation in C. albicans, which could collectively contribute
to its potent in vivo efficacy against systemic candidiasis.