Molecular characterisation and antifungal susceptibility of clinical Trichosporon isolates in India.

In Asian countries, Trichosporon infection is a well-known disease in Japan. In India, the infection is increasingly recognised. The study was conducted to characterise the clinical Trichosporon isolates from India by phenotypic and molecular techniques. A total of 31 Trichosporon clinical isolates, recovered from patients of 14 hospitals across India were sequenced (ITS and IGS1 regions of rDNA). In vitro drug susceptibility testing of the isolates was performed against amphotericin-B, fluconazole, itraconazole, voriconazole and posaconazole. IGS1, rather than ITS sequences, correctly identified the isolates: Trichosporon asahii, 20; Trichosporon ovoides, 3; Trichosporon inkin, 2; Trichosporon asteroides, 1; Trichosporon mucoides, 1; Trichosporon loubieri, 1; Trichosporon debeurmannianum, 1; and Trichosporon dermatis, 1. Trichosporon asahii genotype III was the most common type, followed by genotype I and VII. Both these targets did not help to identify one Trichosporon to the species level. Trichosporon debeurmannianum, T. dermatis and T. asteroides were isolated for the first time from a human disease in India. The minimum inhibitory concentrations for voriconazole and posaconazole were within effective range. The study highlights the presence of wide range of Trichosporon species causing infection in India. Voriconazole or posaconazole may be the better drugs to treat such patients.