Purpose: In this study, we report results from a 5-year surveillance for noncandidal yeast species causing invasive infections from 65 hospitals in China.
Materials and methods: Species identification was carried out by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) supplemented by rDNA sequencing, and fluconazole and voriconazole susceptibilities of yeasts were determined by Clinical and Laboratory Standards Institute (CLSI) disk diffusion methods.
Results: Overall, 884 noncandidal isolates belonging to 38 species were collected. Cryptococcus neoformans  was the most common (75.6%), which also comprised 96.5% of the isolates from cerebrospinal fluid (CSF) and 62.6% from blood, followed by Trichosporon asahii  (6.9%) and Rhodotorula mucilaginosa  (5.1%). Fluconazole susceptibility and resistant rates were 74.1% and 9.7% for C. neoformans  and 81.0% and 5.2% for T. asahii . Voriconazole exhibited good activity in comparison to these two species (99.5% and 98.3% of the isolates, were susceptible). However, 100% of the R. mucilaginosa  isolates were resistant to both azoles. Other noncandidal yeast species showed reduced susceptibility to fluconazole (53.3%) but most were susceptible to voriconazole (94.3%). Over the 5 years, a decrease in the proportion of fluconazole-susceptible isolates was observed for C. neoformans  (90%–67%, P <0.001) and other noncandidal yeast species (91%–66%, P <0.001). Moreover, the prevalence of azole-resistant R. mucilaginosa  increased from 1% to 7% (P <0.001).
Conclusion: The shift in azole susceptibilities in mainland China calls for continued surveillance for noncandidal yeasts.
Keywords: invasive fungal infections, noncandidal yeasts, epidemiology, azole susceptibility, China