2023 Volume 72 Issue 2 Pages 197-204
The genus Rhodotorula and its relative, Sporobolomyces, are yeasts that are ubiquitous in the environment. Most of the Rhodotorula spp. isolated from clinical specimens are Rhodotorula mucilaginosa (formerly known as Rhodotorula rubra), followed by Rhodotorula glutinis and Rhodotorula minuta. We attempted to identify the 17 strains that were clinically isolated and stored (namely, 12 strains of R. mucilaginosa, 2 strains of R. glutinis, 2 strains of R. minuta, and 1 strain of Sporobolomyces salmonicolor) using the conventional method and the BD Phoenix M50 automatic identification sensitivity system (M50) in combination with the BD phoenix yeast ID panel. The concordance rate of M50 with the conventional method was 82.3% (14/17 strains). Although three strains showed different results when using M50, they were identified on the basis of their differential characteristics of nitrate reduction reaction, carcinoid pigment, and watery slime-like colonies by the conventional method. In routine examinations, the identification should be carried out using M50 first, followed by using the conventional method, because it is easy to identify the fungal species. In addition, antifungal susceptibility tests were conducted, and all the isolates were found to be sensitive to AMPH-B and 5-FC and resistant to FLCZ, MCFG, and CPFG. ITCZ and VRCZ showed inconsistent results for sensitivity and resistance. AMPH-B and 5-FC were considered effective as antifungal therapies for Rhodotorula spp. and Sporobolomyces spp.
