Phenotypic switching and its influence on expression of virulence
factors by Candida albicans causing candidiasis in human
immunodeficiency virus-infected patients
Purpose : The purpose of the present study was to determine the degree
of expression of virulence factors such as adherence, cell surface
hydrophobicity (CSH) and production of proteinase by different
morphological forms of Candida albicans causing oral candidiasis in
human immunodeficiency virus (HIV)-infected individuals. Methods : C.
albicans 3153A and two strains isolated from oral thrush in HIV
infected individuals were induced to undergo phenotypic switching by
exposure to UV light and the degree of expression of virulence factors
by the different morphological forms was studied. Results : Three
different morphological forms of C. albicans were obtained namely,
star (S), wrinkled (W) and ring (R) types from the original smooth (O)
variety. It was found that proteinase production was greatest with the
W type followed by the R type and O type. The S type produced the least
proteinase. Expression of cell surface hydrophobicity and adherence was
greatest in the O type followed by the R and then the W type and
finally the S type. Conclusions : The differential expression of
virulence factors occurs with different phenotypic forms of C.
albicans and this may provide a particular morphological type with a
distinct advantage over other types in causing candidiasis
