Back to article: Breaking the bad: Bacillus blocks fungal virulence factors


FIGURE 1: B. safensis inhibits virulence factor production by pathogenic fungi. (A) The C. neoformans wild type strain H99, B. safensis, or a mixture of both were spotted onto L-DOPA agar and incubated at 37°C for three days before being photographed. Fungal cells alone melanize resulting in a black colony color. During dual-species interaction, B. safensis blocks cryptococcal melanization resulting in light beige-colored colonies. Arrowhead points to bacterial swarming. Cn, C. neoformans; Bs, B. safensis. Scale bar, 5 mm. (B) The C. albicans wild type SC5314 was incubated under filament-inducing conditions (10% fetal calf serum, 37°C, 5% CO2) for 24 h with or without B. safensis. Fungal filamentation was then analyzed by DIC microscopy. Arrowheads indicate free-floating bacterial cells, while arrows point to bacteria that have attached to a fungal filament. Ca, C. albicans; Bs, B. safensis. Scale bar, 5 µm.