A COMPARATIVE-STUDY ON CELL-WALL ANTIGENS AND CELL-SURFACE HYDROPHOBICITY IN CLINICAL ISOLATES OF CANDIDA-ALBICANS

Characterization of common cell surface-bound antigens in Candida albi cans strains, particularly those expressed in the walls of mycelial ce lls might be useful in the diagnosis of systemic candidiasis. Hence, a ntigenic similarities among wall proteins and mannoproteins from C. al bicans clinical serotype A and B isolates, were studied using polyclon al (mPAbs) and monoclonal (MAb 4C12) antibodies raised against wall an tigens from the mycelial form of a common C. albicans serotype A labor atory strain (ATCC 26555). Zymolyase digestion of walls isolated from cells of the different strains studied grown at 37 degrees C (germinat ion conditions), released, in all cases, numerous protein and mannopro tein components larger than 100 kDa, along with a 33-34 kDa species. T he pattern of major antigens exhibiting reactivity towards the mPAbs p reparation was basically similar for all the serotype A and B isolates , though minor strain-specific bands were also observed. The immunodet erminant recognized by MAb 4C12 was found to be absent or present in v ery low amounts in C. albicans isolates other than the ATCC 26555 stra in, yet high molecular weight species similar in size (e.g., 260 kDa) to the wall antigen against which MAb 4C12 was raised, were observed, particularly in wall digests from serotype A strains. Cell surface hyd rophobicity, an apparently important virulence factor in C. albicans, of the cell population of each serotype B strain was lower than that o f the corresponding serotype A counterparts, which is possibly due to the fact that the former strains exhibited a reduced ability to form m ycelial filaments under the experimental conditions used.