Human Plasma-Like Medium (HPLM) inducesCryptococcus neoformans in vivocell morphologies

ABSTRACT The fungal pathogen Cryptococcus neoformans (C. neoformans) forms yeast cells of different sizes and morphological characteristics during infection. These features are usually not seen in standard laboratory in vitro conditions. Here, we describe in vivo cell morphologies when C. neoformans is grown in human plasma-like medium at 37°C-5% CO 2 . We observed mixed-size populations of cells less than 1 μm up to 16.8 μm cell diameter, increased capsule size, high chitin and DNA content in larger cells. Our findings show serum is not required for HPLM-induced C. neoformans cellular heterogeneity. Thus, this new method offers an opportunity to investigate factors of C. neoformans that mediate pathogenesis or host-pathogen interactions in a physiologically relevant setting. IMPORTANCE Description of new in vitro culture condition using the human plasma-like medium that supports the formation of the full range of in vivo cell morphologies of C. neoformans .