What Factors Are Implicated in Bd Pathogenicity/Virulence?
The molecular factors influencing Bd pathogenicity and virulence have yet to be conclusively identified. Some evidence suggests that Bd enzymatic activity directly influences pathogenesis. The initial penetration of Bd into amphibian epidermal cells likely requires digestive enzymes. In culture, Bd secretes extracellular proteases that degrade casein and gelatin [18],[19]. At the molecular level, genomic research into Bd is revealing intriguing expression patterns in genes such as those for serine protease and fungalysin metallopeptidase [20], two gene families involved in pathogenesis in other fungal pathogens. Full genomes of two Bd isolates have recently been sequenced, providing new resources for the study of molecular mechanisms of pathogenicity [21].
