Molecular Identification of Saprochaete capitata in Human Blood and Paraffinized Tissue Samples

Abstract

I nvasive fungal infections (IFIs) caused by Candida and Aspergillus species are the most prevalent fungal infections in hospitals; however, those caused by rare fungal species have become increasingly common in recent years. Saprochaete capitata (anamorph; Magnusiomyces capitatus teleomorph), formerly known as Trichosporon capitatum, Geotrichum capitatum, Blastoschizomyces capitatus, and Dipodascus capitatum (1), has emerged as a cause of IFI, especially in patients with hematological malignancies (2, 3). Invasive infections by S. capitata can be confused with Candida infections and may result in high attributed mortality rates due to its low susceptibility to fluconazole and echinocandins, antifungals commonly used in the clinical set for the treatment of candidiasis and aspergillosis (3). The objective of this study was to design a specific PCR assay for the rapid identification of S. capitata from paraffinized tissue samples that would provide useful results with blood samples as well. Nine clinical isolates of S. capitata were assayed: five strains, including Scap 74605,

Invasive Saprochaete Infections: An Emerging Threat to Immunocompromised Patients

“…S. capitata and S. clavata are better distinguished by MALDI-TOF when newer databases such as Bruker BioTyper (3.0 or 3.1) (Bruker Daltonics, Bremen, Germany) or expanded in-house databases are used (Table 1) [8]. The development of polymerase chain reaction (PCR) assays that are highly species specific may be useful in early identification of the organisms from blood or tissue samples, allowing prompt initiation of adequate antifungal therapy; however, such assays are not yet available for commercial use [66]. In the setting of a suspected outbreak, whole-genome sequence (WGS) typing is the best method to determine clonality and to infer strain relatedness [3].…”