Infection with the fungus Candida parapsilosis is a major problem for individuals in intensive care units, as well as for premature infants and immunocompromised adults.
Despite this, little is known about which of its genes account for its virulence. New insight into the virulence mechanisms of C. parapsilosis has now been provided by Attila Gacserand colleagues at the Albert Einstein College of Medicine, New York, who have developed a new way to eliminate genes in C. parapsilosis.
In the study, growth in lipid-rich media of C. parapsilosis engineered to lack lipase activity was shown to be dramatically reduced compared with the growth of normal C. parapsilosis. Furthermore, the mutant fungi were more easily destroyed in vitro by macrophage cell lines and were less virulent when used to infect human cells in vitro and mice in vivo. These data have demonstrated that C. parapsilosis lipase is an important virulence factor for this pathogen and led the authors to suggest that developing drugs that target this lipase might be of therapeutic benefit to individuals who become infected with C. parapsilosis.