Molecular analysis by DiversiLab and antifungal susceptibility by YeastOne of clinical isolates of Trichosporon asahii from Turkey

Didem Özgür, Şahin Direkel, Efdal Oktay, Feza Otag


Background: Trichosporon species are emerging fungal pathogens capable of causing localized or systemic infections, especially in immunocompromised patients with cancer, haematological diseases or organ transplantation (1). Despite the increasing incidence of Trichosporon infections and the increased antifungal resistance of the genus, there are few reports on antifungal susceptibilities of clinical Trichosporon strains (2). The objective of the present study was to investigate the relationship of Trichosporon asahii strains between antifungal susceptibility and clonal similarity.

Material/methods: From September 2008 through October 2014, a total of 38 hospitalized patients were infected or colonized by Trichosporon asahii. Only one isolate per patient was used in this study. İdentification of strains was performed by biochemical tests using the Vitek 2 system. Clonal relationships of the strains determined by semi-automated rep-PCR (DiversiLab, bioMerieux, France) system. A total of all strains were tested using Sensititre YeastOne (Trek diagnostics, ABD) to determine the minimum inhibitory concentrations (MICs) to amphotericin-B, fluconazole, itraconazole, posaconazole, voriconazole, 5-fluorocytosine, anidulafungin, caspofungin and micafungin.

Results: MICs ranged from 8-32 g/ml, 0.03-1 g/ml, ≤0.08-0.25g/ml, 0.03-0.5 g/ml, 0.5-4 g/ml, for 5-fluorocytosine, posaconazole, voriconazole, itraconazole, fluconazole, amphotericin B, respectively. The MICs value for anidulafungin, caspofungin and micafungin were ≥0.08 g/ml which were detected not sensitive in all isolates. Voriconazole was the most potent drug against T. asahii, followed by fluconazole, itraconazole and 5-flucytosine. The DiversiLab system generated rep-PCR DNA fingerprints for each of the isolates. We found five clones (A to E) which include similar strains; however, isolates of four clones were observed with >90%similarity.

Conclusions:This study showed that voriconazole was the most active agent, followed by fluconazole and itraconazole according to published results (3,4). Although no relationship with epidemiological data, such as the date or clinical unit of hospitalization, was observed in the same clones, the determination of clonal relationship may be a useful tool for fast and accurate management of nosocomial outbreaks.


abstract No: 


Full conference title: 

26th European Congress of Clinical Microbiology and Infectious Diseases
    • ECCMID 26th (2016)