Breakthrough Trichosporon asahii Fungemia in Neutropenic Patient with Acute Leukemia while Receiving Caspofungin

A 47-year-old man with newly diagnosed acute myeloblastic leukemia and non-insulin-dependent diabetes mellitus developed Trichosporon asahii fungemia while receiving caspofungin as empirical antifungal therapy. The diagnosis was based on repeated isolation of T. asahii in culture of blood for three times. Despite treatment with amphotericin B and voriconazole, the patient died. The in vitro antifungal susceptibilities of the T. asahii isolates were only available after the patient died. In vitro antifungal susceptibility tests showed high caspofungin and amphotericin B minimal inhibitory concentrations (MICs) value for this Trichosporon strain (MICs, 16 μg/ml, and > 32 μg/ml, respectively). Fluconazole, itraconazole, and voriconazole exhibited low MICs in vitro (MICs, 4 μg/ml, 0.5 μg/ml, and ≤ 0.015 μg/ml, respectively). Our experience strongly suggest that identification and antifungal susceptibility testing for T. asahii in neutropenic patients who may develop signs of infection in the presence of caspofungin as well as broadspectrum antibiotics treatment should not be overlooked.