, a rare pathogen of human invasive infections, and literature review.

Background: is a rare fungal species that has not been described in human invasive infections.

Patients And Methods: In this study, we investigated two isolates from patients with invasive infections in two hospitals in China, as part of the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program. Both patients were under immunocompromised conditions.

Results: On chromogenic agar, isolates were dark blue, similar to the color of , but the characteristic moist colony appearance was quite different from that of . The two isolates were misidentified as and by the VITEK 2 YST system. The rDNA internal transcribed spacer (ITS) region and the D1/D2 domain sequences of the two isolates were 100% identical to type strain CBS10761. The sequence of the intergenic spacer region-1 also clearly distinguished the species. Of the three matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems, Bruker Biotyper and Autobio MS correctly identified the two isolates to species level, whereas Vitek MS systems misidentified them as or . Echinocandins exhibited no in vitro activities against the two isolates. In addition, the isolates exhibited intermediate susceptibility to fluconazole (with minimal inhibitory concentrations [MICs] of 8 and 16 µg/mL) and itraconazole, voriconazole, and posaconazole (MICs of 0.25-1 µg/mL). demonstrated susceptibility to amphotericin B with MIC of 1 µg/mL. The MICs of fluconazole and voriconazole in our study were higher than the MIC of 62 for isolates (4 and 0.064 µg/mL) in the CHIF-NET program.

Conclusion: This case study points to a possible emergence of as an opportunistic human invasive fungal pathogen, and the reduced susceptibility should be noted.