Hyphal Growth in Human Fungal Pathogens and Its Role in Virulence

Abstract

Most of the fungal species that infect humans can grow in more than one morphological form but only a subset of pathogens produce filamentous hyphae during the infection process. This subset is phylogenetically unrelated and includes the commonly carried yeasts,Candida albicans,C. dubliniensis, andMalasseziaspp., and the acquired pathogens,Aspergillus fumigatusand dermatophytes such asTrichophyton rubrumandT. mentagrophytes. The primary function of hypha formation in these opportunistic pathogens is to invade the substrate they are adhered to, whether biotic or abiotic, but other functions include the directional translocation between host environments, consolidation of the colony, nutrient acquisition and the formation of 3-dimensional matrices. To support these functions, polarised hyphal growth is co-regulated with other factors that are essential for normal hypha functionin vivo.