Simplified J774A.1 macrophage assay for fungal pathogenicity demonstrates non-clinical Nakaseomyces glabratus strains survive better than lab strains.

Abstract

Nakaseomyces glabratus (formerly known as Candida glabrata ) is the second most common cause of candidiasis, whereas the closely related yeast, Saccharomyces cerevisiae, causes few infections. Macrophages can control N. glabratus infections through phagocytosis, but in cell culture, N. glabratus is able to persist in macrophages better than non-pathogenic yeast. Using J774A.1 macrophages, we simplified a standard persistence/survival assay by counting yeast cells with flow cytometry and incorporating an antifungal treatment. These improvements minimized wash steps and variation so fewer replicates were needed. Here, we demonstrate that loss of NgTUP11 does not lower pathogenicity, and that three non-clinical N. glabratus strains survive in macrophages better than a laboratory strain.