Effects of melanin upon susceptibility of XXXX to antifungals.

@entity3034 @entity9203 @entity2379 @entity2380 @entity1327
Melanin is a recognized virulence factor in @entity1327 ; several pathogenetic mechanisms have been suggested. We studied melanin as an antifungal resistance factor. The growth of laccase-active strains of @entity1327 and C. albidus in @entity3034 resulted in the production of black pigment. The formal minimal inhibitory concentrations (MICs) of @entity2379 and @entity2380 were not changed by melanization. However, when we examined those wells which contained inhibited cells, we found live cells only in wells containing melanized @entity1327 . In contrast, melanization did not protect C. albidus from killing by @entity2379 . In an @entity2379 time-kill study of @entity1327 , significantly more melanized cells than non-melanized survived for the first few hours. Fluorescence microscopy and flow cytometry analyses showed that fewer melanized cells were stained with the fluorescent dye MitoRed. Incubation of MitoRed (the model) or @entity2379 with @entity9203 extracted from @entity1327 decreased the free concentrations of these substances. @entity2380 , in contrast, was not removed from solution by melanin. This suggests that neoformans cryptococcal melanin deposited @entity2379 in the cell wall binds, reducing its effective concentrations.
