FIG 1.

C. albicans killing and PM permeabilization in response to HOCl. (A) C. albicans cells (strain SC5314) were incubated with the indicated concentration of HOCl for the times indicated on the x-axis. The viable CFUs were determined by plating on agar medium. The results represent the average of four independent experiments. (B) C. albicans strain SC5314 was incubated with 20 µM HOCl for the time indicated on the x-axis and then stained with SYTOX Green, a membrane impermeable fluorescent dye that binds double-stranded nucleic acids.The results represent the average of three independent experiments. Error bars indicate SD. (C) The effects of a mixture of HOCl and CuSO₄ were tested in diffusion assays, also known as halo assays. Then, 2.5 × 10⁵ SC5314 cells were spread onto the surface of a minimal medium plate, and then a 5-µL spot containing the indicated concentration of HOCl, CuSO₄, or a mixture containing half the amount of HOCl and CuSO₄ used in single compound assays was placed on the surface of the agar. The diameter of the zone of growth inhibition (halo) surrounding each spot was recorded after incubation for 24 or 48 h at 30°C. The results represent the average of four independent assays, each done in duplicate.