Enzymes conferring virulence traits among human pathogenic fungi

Fungi are widespread in the environment, but only a limited number of pathogenic species are commonly found primarily as opportunistic pathogens that affect immunocompromised individuals. Mycotic infections, if not promptly diagnosed and treated, can lead to conditions with high morbidity and mortality. The common virulence factors among the opportunistic fungal pathogens are generally associated with adhesion and host tissue invasion, morphotypic switching, factors facilitating metabolic adaptation from outside to inside of the host, and the factors needed for immune evasion inside the host. There are certain enzymes that play vital roles in the progression of fungal pathogenesis, including phospholipases, proteases, hemolysins, superoxide dismutases, and ureases, among others. The different stages of host-pathogen interaction can be significantly impacted by altering the expression or activity of these enzymes. Furthermore, the patterns of enzyme expression serve as important indicators of the disease progression in many cases. Therefore, the enzymes of pathogenic fungi are important for both understanding the molecular mechanism of pathogenesis and discovering the innovative strategies for the diagnosis and treatment of fungal infections. This chapter presents an account of the enzymes conferring virulence in common human pathogenic fungi.