Purification and germination of Candida albicans and Candida dubliniensis chlamydospores cultured in liquid media

Abstract

peer-reviewedCandida albicans and Candida dubliniensis are the only Candida species that have been observed to produce chlamydospores. The function of these large, thick-walled cells is currently unknown. In this report we describe the production and purification of chlamydospores from these species in defined liquid media. Staining with the fluorescent dye FUN-1 indicated that chlamydospores are metabolically active cells, but that metabolic activity is undetectable in chlamydospores that are greater than 30 days old. However, 5-15 day old chlamydospores could be induced to produce daughter chlamydospores, blastospores, pseudohyphae and true hyphae depending on the incubation conditions used. Chlamydospores that were pre-induced to germinate were also observed to escape from murine macrophages following phagocytosis, suggesting that these structures may be viable in vivo. Mycelium-attached and purified chlamydospores rapidly lost their viability in water and when subjected to dry stress, suggesting that are unlikely to act as long-term storage structures. Instead, our data suggest that chlamydospores represent an alternative specialised form of growth by C. albicans and C. dubliniensis