| Abstract: | Secreted phospholipase has been recently proposed as a virulence determinant in Cryptococcus neoformans as well as Candida
albicans. This issue of cryptococcal phospholipase requires screening of phospholipase production in a larger number of isolates
from clinical and environmental sources. In this study we examined phospholipase production in a total of 67 C. neoformans
isolates from AIDS patients and bird droppings by using the egg-yolk plate method. Phenoloxidase activity, capsule size and
growth at 37 °C were also measured in these strains in order to observe a possible relationship between phospholipase production
of different C. neoformans strains and its virulence. Four of the 21 AIDS strains at 28 °C and 1 at 37 °C did not produce
phospholipase, respectively. In contrast, 38 and 34 of the 46 bird dropping strains were negative for phospholipase production
at 28, and 37 °C, respectively. Statistical analysis revealed a significant difference in phospholipase production, capsule
size and growth ability at 37 °C, but not phenoloxidase activity, between the AIDS and the bird dropping strains. The highly
prevalent distribution of phospholipase activity in the AIDS strains suggests a role of the enzyme in invading the host.
This revised version was published online in June 2006 with corrections to the Cover Date. |
