Identification of Candida albicans cell wall antigens lost during subculture in synthetic media.

A high variability in reactivity was observed when Candida albicans strains freshly isolated from both patients with candidiasis and asymptomatic carriers were tested against different human sera. The highest reactivity was observed in C. albicans strains isolated from blood cultures. This high reactivity was observed when the isolates were tested against sera from patients with Candida oesophagitis, patients with vulvovaginal candidiasis, or asymptomatic carriers but not against sera from blood donors. The antigenic reactivity of the strongly reactive strains, but not that of the weakly reactive strains, decreased during subculture in synthetic media. Five major components of an apparent molecular mass of > 200, 67-70, 49-52, 33-35 and 29-31 kDa were observed in alpha-mannosidase extracts from C. albicans strains from both blood cultures (Group I) and patients with Candida oesophagitis (Group II) subcultured in synthetic media for different times. Changes in staining intensity through the different subcultures were observed for some bands. Group I strains showed a decrease in staining intensity for bands of > 200 and 67-70 kDa, an increase for bands of 33-35 and 29-31 kDa, but no changes were observed for the band of 49-52 kDa. Group II strains showed opposite changes in banding intensity. A decrease in staining intensity was observed for the proteins of 33-35 and 29-31 kDa, an increase for the protein of 49-52 kDa, and no change in intensity was observed for the band of 67-70 kDa. A component of > 200 kDa showed an irregular expression through the subcultures. The main antigen present in extracts from the first subculture of isolates from Group I and II had a molecular mass of 67-70 kDa. It could be related to the P antigens since it disappeared following subculture of the strains in synthetic media.