<em>Trichosporon dohaense</em>, a rare pathogen of human invasive infections, and literature review

Abstract

BackgroundTrichosporon dohaense is a rare fungal species that has not been described in human invasive infections.Patients and methodsIn this study, we investigated two T. dohaense isolates from patients with invasive infections in two hospitals in China, as part of the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program. Both patients were under immunocompromised conditions.ResultsOn chromogenic agar, T. dohaense isolates were dark blue, similar to the color of Candida. tropicalis, but the characteristic moist colony appearance was quite different from that of T. asahii. The two isolates were misidentified as T. asahii and T. inkin by the VITEK 2 YST system. The rDNA internal transcribed spacer (ITS) region and the D1/D2 domain sequences of the two T. dohaense isolates were 100% identical to T. dohaense type strain CBS10761T. The sequence of the intergenic spacer region-1 also clearly distinguished the species. Of the three matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems, Bruker Biotyper and Autobio MS correctly identified the two isolates to species level, whereas Vitek MS systems misidentified them as T. ovoides or T. asteroides. Echinocandins exhibited no in vitro activities against the two T. dohaense isolates. In addition, the isolates exhibited intermediate susceptibility to fluconazole (with minimal inhibitory concentrations [MICs] of 8 and 16 µg/mL) and itraconazole, voriconazole, and posaconazole (MICs of 0.25–1 µg/mL). T. dohaense demonstrated susceptibility to amphotericin B with MIC of 1 µg/mL. The MICs of fluconazole and voriconazole in our study were higher than the MIC50 of 62 for T. asahii isolates (4 and 0.064 µg/mL) in the CHIF-NET program.ConclusionThis case study points to a possible emergence of T. dohaense as an opportunistic human invasive fungal pathogen, and the reduced susceptibility should be noted.

Comparison of Autof ms1000 and Bruker Biotyper MALDI-TOF MS Platforms for Routine Identification of Clinical Microorganisms

“…It is characterized by the use of the latest cloud database and an external pump to achieve vacuum rapidly. The use of the Autof ms1000 has been reported in a case of Trichosporon dohaense infection [14], a novel isolate of Legionella qingyii [15], and an evaluation in Bacteroides fragilis group isolates [16]. Recently, the Autof ms1000 was evaluated for clinical isolates in China, and it showed comparable identification performance to the Bruker Biotyper [17].…”

COVID-19-associated brain abscess caused by Trichosporon dohaense: A case report and review of literature

“…To our knowledge, this is also the first case of brain abscess caused by this rare Trichosporon species. So far, only seven cases of infection (4 cases of superficial infections, 2 cases of fungemia and 1 catheter-associated infection) caused by this fungus have been reported in literature ( Table 1 ) [ [8] , [9] , [10] , [11] ].…”

“… Reference (Year) GenBank Accession No. (ITS) Patient demographics Clinical specimen Infection Antifungal therapy Outcome Patient origin Age/Gender Myco 643 Taj-Aldeen et al (2009) [ 8 ] FJ228476 Qatar 70/F Toenail Onychomycosis Not known Not known Myco 194 Taj-Aldeen et al (2009) [ 8 ] FJ228474 Bangladesh 41/M Catheter Catheter-site infection Not known Not known Myco 483 Taj-Aldeen et al (2009) [ 8 ] FJ228475 India 34/M Skin scraping Tinea pedis Oral TRB + topical ECO + Whitfield’s ointment Recovered AUMC 10212 Abdel-Sater et al (2016) [ 9 ] KU200438 Egypt 40/F Fingernail Onychomycosis Not known Not known 10PU193 Yu et al (2018) [ 10 ] MG857685 China 56/M Blood Fungemia Not given LFU …”

“…Accurate identification of T. dohaense is important for initiation of appropriate antifungal therapy. T. dohaense is morphologically indistinguishable from other Trichosporon species and can easily be misidentified as Candida by conventional methods like CHROMagar and VITEK 2 YST [ 8 , 10 ]. Though MALDI-TOF MS serves as a promising tool for routine identification of most Trichosporon spp., the mass spectral data of T. dohaense are not represented in VITEK® MS (bioMérieux, Marcy l'Etoile, France) database, and therefore, our isolate was misidentified as T. ovoides / T. asteroides .…”

“…Though MALDI-TOF MS serves as a promising tool for routine identification of most Trichosporon spp., the mass spectral data of T. dohaense are not represented in VITEK® MS (bioMérieux, Marcy l'Etoile, France) database, and therefore, our isolate was misidentified as T. ovoides / T. asteroides . However, Bruker Autoflex Speed (Bruker Daltonics, Bremen, Germany) contains the mass spectral data of T. dohaense and can reliably identify it [ 10 ]. Sequencing-based platforms targeting the ITS (ITS1-5.8S-ITS2) and LSU regions of fungal DNA have high discriminatory power and can provide accurate identification to the species level [ 8 , 17 , 18 ].…”