Cryptococcus bacillisporus sp. nov.: Serotype B-C of Cryptococcus neoformans

Serotypes B and C of Cryptococcus neoformans are described as a separate species, C. bacillisporus sp. nov. C. bacillisporus could be distinguished from C. neoformans by creatinine metabolism. Serotype B and C isolates utilized creatinine much more readily than A and D, resulting in increased ammonia production and alkaline pH. Based on these findings, a creatinine-dextrose-bromothymol blue agar medium (pH 5.7) was developed as a single-step culture method for separation of the two species. Isolates of C. neoformans can be distinguished from C. bacillisporus with 97% accuracy by 48 h.