FIG 4.

Mefloquine and mefloquine derivatives inhibit C. albicans filamentation at sub-growth-inhibitory concentrations. Candida albicans strain SC5314 was inoculated into YPD containing drug or DMSO and incubated for 1 h at 37°C with shaking. The cultures were supplemented with 1% fetal bovine serum and grown at 37°C with shaking for 1 h to induce filamentation. Samples of the cultures were stained with propidium iodide, harvested, and examined by microscopy. (A) Bright-field images of live C. albicans cells show that mefloquine and the mefloquine derivatives prevent filamentation. (B) Quantitative analysis was performed by visually inspecting the microscopy images of live cells in the yeast, pseudohyphal, and hyphal forms. (C) Quantitative analysis of live C. albicans cells indicates that filamentation is affected by mefloquine in a dose-dependent manner.