Abstract:

Objective To monitor the drug resistance of clinical isolates of Candida parapsilosis species complex（CPC） in eastern China region. Methods CPC isolates were isolated from 47 hospitals in eastern China region from January 2017 to December 2023. The reference laboratory was the Department of Clinical Laboratory of Shanghai East Hospital （South Branch） of Tongji University. The minimum inhibitory concentrations（MIC） of the isolates against 10 antifungal drugs were determined by microbroth dilution method. The in vitro drug susceptibility test results were analyzed according to the Clinical and Laboratory Standards Institute（CLSI） M27M44s and M57s documents. Results A total of 941 isolates of CPC were collected. The proportions of different CPC were as follows：Candida parapsilosis（83.21%，783 isolates），Candida orthopsilosis（10.20%，96 isolates）and Candida metapsilosis（6.59%，62 isolates）. The drug resistance rates of Candida parapsilosis to fluconazole and voriconazole were 12.80% and 3.50%，respectively. The non-wild-type Candida metapsilosis to fluconazole and voriconazole were 39.6% and 37.7%，respectively. Non-wild-type Candida orthopsilosis showed 14.0%，9.3% and 12.8% to caspofungin，fluconazole and voriconazole，respectively. The MIC of isavuconazole against CPC was 0.008 mg·L^-1，which was lower than the other 9 antifungal drugs. Conclusions There is a certain difference in the resistance of CPC to the tested antifungal drugs. Candida parapsilosis and Candida metapsilosis have higher resistance rates to fluconazole and voriconazole. All the isolates have low MIC for isavuconazole and can be recommended as first-line drugs for antifungal therapy.

Key words: Candida orthopsilosis, Candida parapsilosis, Candida metapsilosis, In virto drug susceptibilty test, Eastern China region