Invasive Infections Due to Trichosporon : Species Distribution, Genotyping, and Antifungal Susceptibilities from a Multicenter Study in China

Abstract

A total of 133 clinical Trichosporon isolates were collected in the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program in 2009 to 2016. Accurate identification was performed by sequencing of the intergenic spacer 1 (IGS1) region. Among these isolates, Trichosporon asahii (108 isolates [81.2%]) was the leading species, followed by Trichosporon dermatis (7 isolates [5.3%]), Trichosporon asteroides (5 isolates [3.8%]), Trichosporon inkin (5 isolates [3.8%]), Trichosporon dohaense (3 isolates [2.3%]), and 1 isolate (0.7%) each of Trichosporon faecale, Trichosporon jirovecii, Trichosporon mucoides, Trichosporon coremiiforme, and Trichosporon montevideense. Both the Vitek mass spectrometry (MS) (bioMérieux, Marcy l'Etoile, France) and Bruker Biotyper MS (Bruker Daltonics GmbH, Germany) platforms gave high levels (Ͼ97.5%) of correct identification when the species were present in the database. The geometric mean (GM) of amphotericin B MICs for T. asahii was 2-fold higher than that for non-asahii Trichosporon. High fluconazole MICs (Ն8 g/ml) were observed for 25% of T. asahii isolates (27/108 isolates) and 16% of non-asahii Trichosporon (4/25 isolates) isolates. Itraconazole MICs were Յ0.5 g/ml for 89.5% of the isolates. Voriconazole was the most potent antifungal agent in vitro, with a GM of 0.09 g/ml. Genotyping of the isolates using IGS1 sequence alignment revealed that genotype 1 was most common (41.7%), followed by genotype 4 (31.5%), genotype 3 (23.1%), genotype 5 (0.9%), genotype 6 (0.9%), and genotype 7 (1.8%). Our data on species distribution, genotypes, and antifungal susceptibilities may contribute to a better understanding of the epidemiology of invasive Trichosporon infections throughout China.

Epidemiological investigation for grouped cases of Trichosporon asahii using whole genome and IGS1 sequencing

“…We also found a high proportion of patient under 15 years (32.14%, 9/28) and a high mortality rate at three months (46.15%, 12/26). As reported in the literature, 12,14,32‐34 all T. asahii isolates were intrinsically resistant to flucytosine and less susceptible to fluconazole and amphotericin B while voriconazole had the most potent in vitro activity with MIC50 and MIC90 of 0.06 and 0.25 mg/L, respectively. Voriconazole is the treatment usually recommended for deep‐seated trichosporonosis 34 …”

“…This species is rarely involved in white piedra but is frequently recovered from patients with summer‐type hypersensitivity pneumonitis (SHP), an allergy developed after repeated inhalation of arthroconidia 8 . It is also isolated from immunocompromised patients and is the major Trichosporon species responsible for life‐threatening deep‐seated infection called trichosporonosis, 9‐13 mainly in patients with haematological malignancies 14‐16 . Fungaemia due to Trichosporon sp.…”

“…Up to now, 12 IGS1 haplotypes have been identified and a correlation between haplotype and geographical origin of the isolates has been described. Indeed, haplotype 1 is ubiquitous but predominant in Japan, China, South America, Turkey and Thailand, while haplotype 3 is more frequent in USA, Thailand and also in houses of SHP patients in Japan 12,20 . Haplotype 5 is also frequent in USA and haplotype 7 in Thailand 20,21 .…”

Epidemiological study ofTrichosporon asahiiinfections over the past 23 years

“…In addition, different species of Trichosporon possess different drug sensitivities. For example, amphotericin B has a higher minimum inhibitory concentration (MIC) against T. asahii, T. faecale and T. coremiiforme, while T. inkin, T. ovoides, T. japonicum, T. domesticum, T. montevideense and T. cutaneum have lower MICs [46,[53][54][55][56]. Therefore, it is important to accurately analyse the epidemiological characteristics of different species of Trichosporon so the susceptibility and risk factors of infection can be obtained.…”

Genotyping and Antifungal Susceptibility of Trichosporon asahii Strains Isolated from the Clinical Samples in a University Training and Research Hospital in Turkey

“…In the review of Almeida Junior and Hennequin, they stated that there was no correlation between individual genotypes and sensitivities, but when combined the results of four different studies, they emphasized that VOR MIC values for genotype 3 strains were higher than genotype 1 strains, and this difference was statistically significant (1). Similarly, in the study of Guo et al (2019), the authors found that genotype 3 strains exhibited higher AMB MICs than did genotype 1 and 4 strains (7).…”