To analyze the biological characteristics and the sensitivity to anti-fungal drugs of S. ciferrii and to provide some references for the accurate identification and treatment.

47 strains of S. ciferrii were collected from First Hospital, Sun Yat-Sen University and Sanxiang Hospital. All the strains were identified by VITEK 2 system. The phylogenetic tree constructed by ITS sequence was used to analyze the phylogenetic relationship between S. ciferrii and other common clinical candida. All of the ITS sequences were downloaded from the NCBI database. The phylogenetic tree was constructed using Neighbor-Joining method by MEGA 7.0. The susceptibilities of 5-fluorocytosine, amphotericin B, fluconazole, itraconazole, and voriconazole were tested by the ATB-FUNG3.

The colony of S. ciferrii was creamy, rough, and wrinkled after 1 week’s incubation. The colony appeared blue on CHRMagar medium. The phylogenetic relationship analysis showed that the relationship between S. ciferrii and Saccharomyces cerevisiae was closer than that of other common Candidas. The results of anti-fungal drugs sensitivity showed the strains had high resistance against fluconazole, with a drug-resistant rate of 70.2%. The MIC₅₀ of 5-fluorocytosine was 4.0 μg/ml, and the MIC ₉₀ ≥ 32.0 μg/ml. The MIC ₅₀ of amphotericin B was 0.5 μg/ml, and the MIC ₉₀ 1.0 μg/ml. The MIC ₅₀ of itraconazole was 0.25 μg/ml, and the MIC ₉₀ 1.0 μg/ml. The MIC ₅₀ of voriconazole was 0.5 μg/ml. and the MIC ₉₀ 1.0 μg/ml.

S. ciferrii showed high resistance against antifungal drugs. In order to select antibiotics accurately and reasonably, clinical laboratory staff should pay attention to the cultivation, identification, and susceptibility test of S. ciferrii. The hospital infection control department also should pay attention to the monitoring of S. ciferrii.

Stephanoascus ciferrii; Sensitivity to anti-fungal drugs; Biological characteristics