Chlamydospore formation on Staib agar. Observations made before Candida dubliniensis was described.

When routinely using Staib agar to detect Cryptococcus neoformans in AIDS patients by the brown colour effect of its colonies, rough-looking colonies of a questionable variety of Candida albicans were also found. Microscopically, these colonies consisted of pseudohyphae with abundant masses of chlamydospores. However, the colonies of C. albicans were smooth-edged and formed by round-oval blastospores only. Such observations were made during the mycological supervision of 36 cryptococcosis cases during the 1987-94 period. All these questionable cultures of Candida spp. were discarded. However, because the corresponding photographs of and records on such strains were found to be identical with those recently published by molecular biologists under the title 'Chlamydospore formation on Staib agar as a species-specific characteristic of Candida dubliniensis' [Staib, P. & Morschhäuser, J. (1999) Mycoses 42, 521-524], the present communication presents a report on such observations in a representative and exemplary case of an AIDS patient.