Colonization of living skin equivalents by Malassezia furfur

Initial colonization events and yeast-hyphal transformation by Malassezia fur;fur were observed using living skin equivalent (LSE) models for growth. Yeast cells were inoculated onto the LSEs which were incubated in CO2-independent media at 37 degrees C for variable lengths of time. Assessment of fungal growth and invasion was by light- and scanning electron microscopy (SEM). Viability counts of M furfur were determined by a method of washing and serial dilution. Yeast cells had retained their viability and increased in number approximate to twofold over a 4-day period of incubation. Yeast-to-hyphal transition was not achieved in this model. Random destruction of the uppermost layers of the stratum corneum was observed in the presence of M. furfur. LSEs therefore appear to be a promising model for mechanisms of growth of cutaneous organisms.