Isolation of Scedosporium apiospermum (Teleomorph: Pseudallescheria apiospermd) from an acute myeloid leukemia patient

Abstract

Scedosporium apiospermum is an emerging opportunistic pathogen that may lead to life-threatening infections especially in immunosuppressive individuals. In this report, S.apiospermum infection in a 62 year old male patient with acute myeloid leukemia was presented. During remission-induction chemotherapy, piperacillin-tazobactam therapy was started for febrile neutropenia. Since fever had continued, treatment was switched to imipenem and also amphotericin B deoxycholate was added to the treatment protocol. Because of allergic reaction to amphotericin B, caspofungin was started at the fifth day of neutropenic fever. Following imaging studies with high resolution computerized thorasic tomography, antifungal therapy was changed to voriconazole due to findings suggestive of invasive aspergillosis. Since galactomannan antigen was found negative at the first day of voriconazole therapy, bronchoalveolar lavage material from apical segment of the left lower lobe was cultured onto various microbiologic media. S.apiospermum (Teleomorph: Pseudallescheria apiosperma) was isolated on the fourth day of cultivation. According to CLSI M38-A2 microdilution procedure, minimum inhibitory concentrations (MIC) of voriconazole, caspofungin, amphotericin B and posaconazole were found as 0.06, 2, 8 and 4 µg/ml, respectively. Since neutropenia was resolved, the patient was discharged with continued voriconazole therapy. It was concluded that antifungal susceptibility tests should be performed for Scedosporium species and the results should be compared to the clinical response. The determination of MIC breakpoints may provide useful information for the recommendation and use of optimal choices for the treatment of Scedosporium infections.