The observation that C. albicans secretes phospholipase prompted Pugh and Cawson (150) to develop a lecithin-based cytochemical method to detect this enzyme. In a subsequent study, these authors used this method (149) in conjunction with a chicken chorioallantoic membrane model to evaluate ultrastructural details of candidal invasion and to determine
the site of phospholipase production. Invasion was initiated by placing stationary-phase blastospores of C. albicans
on the membrane, which stimulated cellular changes in the blastospores. Many of the blastospores developed hyphae with
phospholipase activity concentrated at the growing tip. The activity was highest where the hyphae were in direct contact
with the membrane (149). In general, only hyphae invaded the membrane successfully. Based on these results, the investigators
proposed that extracellular phospholipases were important
in the invasion of tissue by C. albicans