Molecular identification, genotyping, and antifungal susceptibility testing of clinically relevant Trichosporon species from Argentina

Abstract

Trichosporon species are emerging causative agents of mycoses; most are documented in immunocompromised patients. Species identification is important for epidemiological purposes in order to better define species clinical associations and to improve antifungal treatment. Here, we studied a collection of 41 Trichosporon strains recovered from hospitalized patients in Argentina. All strains were identified by sequencing the D1/D2 domain of 26S, internal transcribed spacer (ITS) regions, and intergenic spacer 1 (IGS1) region. In addition, we determined the IGS1 region genotypes of the suspected T. asahii strains. Antifungal susceptibility of all strains was investigated. Thirty-eight of the 41 strains in this study were identified as follows: 29 T. asahii, 3 T. inkin, 3 T. montevideense, 2 T. faecale, and 1 T. dermatis. The identity of the three remaining strains could not be confirmed. Strain DMic 114126 (Culture collection of the Mycology Department (DMic), National Institute of Infectious Diseases "Dr. Carlos G. Malbrán".) may represent a T. asahii subspecies or a new Trichosporon species, strain DMic 94750 was identified as T. cf. guehoae and strain DMic 114132 as T. cf. akiyoshidainum. The distribution of T. asahii genotypes was as follows: 12 genotype 3, 9 genotype 1, 4 genotype 4, 2 genotype 5, and 2 genotype 7. Amphotericin B minimal inhibitory concentrations (MICs) were ≤1 mg/l for 78% (32/41) of the strains. Fluconazole MICs were ≥2 mg/l for 90% of the strains. However, itraconazole, voriconazole, ketoconazole, and posaconazole MICs were ≤1 mg/l for 100% of the strains. Terbinafine MICs were ≤1 mg/l for 98% 40/41 of the strains.

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

“…The distributions of the T. asahii genotypes varied among different regions. Genotype 1 predominated in our study in China, which is similar to the prevalences in Spain (24), Mexico (25), Brazil (7), Turkey (26), and Japan (3), while genotypes 1 and 3 occur in Argentina (27), Taiwan (28), Thailand (29), and India (30) and genotypes 3 and 4 occur in Greece (31). Interestingly, our results found that genotype 3 strains exhibited higher AMB MICs (Ն2 g/ml) than did genotype 1 strains (P ϭ 0.009).…”

Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen

“…Details from 19 studies having tested at least 10 Trichosporon clinical isolates for a given species with a microdilution method are presented in Tables 3 – 8 (Arikan and Hasçelik, 2002 ; Paphitou et al, 2002 ; Ramos et al, 2004 ; Metin et al, 2005 ; Rodriguez-Tudela et al, 2005 ; de Oliveira Silva et al, 2008 ; Chagas-Neto et al, 2009 ; Taj-Aldeen et al, 2009 ; Thompson et al, 2009 ; Lemes et al, 2010 ; Mekha et al, 2010 ; Guo et al, 2011 ; Sun et al, 2012 ; Tsai et al, 2012 ; Hazirolan et al, 2013 ; Yang et al, 2013 ; Arabatzis et al, 2014 ; Taverna et al, 2014 ; Montoya et al, 2015 ). Up to now, there is no recommendation from the two main consortia (EUCAST and CLSI) regarding the AST of Trichosporon .…”

Disseminated cutaneous trichosporonosis in an adult bone marrow transplant patient

“…Voriconazole has emerged as the first-choice antifungal agent while maintaining efficacy against Trichosporon with the minimum inhibitory concentration (MIC 50 ) estimated at 0.03–0.5 μg/mL in the literature. [10] This case serves to remind physicians to consider Trichosporon species in cases of breakthrough infection or treatment failure under echinocandins or amphotericin therapy.…”