Recovery and studies on chlamydospore-negative Candida albicans isolated from clinical specimens

During a period of 31 months, we isolated 3525 strains of Candida albicans from different patient specimens. Twenty-five of these (0.71%), obtained from female patients, displayed morphological and biochemical characteristics different from those seen in typical C. albicans. The failure to produce chlamydospores in cornmeal agar was the common denominator in this group. The strains were categorized into three groups: Group I contained 13 isolates that produced germ tubes but were unable to assimilate trehalose (TRE), glucosamine (GLN) and N-acetylglucosamine (NAG); Group II contained four isolates that were germ-tube positive and able to assimilate TRE, GLN and NAG; and Group III contained eight isolates that were germ-tube negative and able to assimilate TRE, GLN and NAG. These isolates were further studied to determine their biotypes, serotypes, extracellular proteinase production and antifungal susceptibility. Group I isolates were of serotype B, whereas Groups II and III were serotype A. All isolates produced high to moderate amounts of extracellular proteinase. Six group I isolates were resistant to 5-fluorocytosine, whereas all groups II and III isolates were susceptible to this drug. Five of the 12 isolates of group II and III were resistant to fluconazole, itraconazole and ketoconazole.