Genetic analysis of emerging fungal pathogens: Trichosporon asahii

Area of Science:

• Medical Mycology
• Molecular Biology
• Population Genetics

Background:

• Trichosporon asahii is an emerging opportunistic fungus causing fatal infections, particularly in immunocompromised individuals.
• While T. asahii infections are reported in Thailand, research on its genetic diversity remains limited.
• This study addresses the knowledge gap by investigating clinical isolates from Thailand.

Purpose of the Study:

• To assess the genetic diversity of 51 clinical Trichosporon asahii strains from urine samples in Thailand.
• To evaluate the utility of specific genes (IGS1, TUB1, ATP, PHCP, TOP1) for molecular typing.
• To understand the population structure of T. asahii in the region.

Main Methods:

• Sequencing of beta-1-tubulin (TUB1), copper-exporting ATPase (ATP), phosphate carrier protein (PHCP), and topoisomerase-1 (TOP1) genes.
• Analysis of intergenic spacer 1 (IGS1) sequences from previous studies.
• Haplotype analysis to determine genetic variation across the studied genes and IGS1.

Main Results:

• A low number of haplotypes were identified: 3 for IGS1, 3 for TUB1, 2 for ATP, 2 for PHCP, and 2 for TOP1.
• The findings suggest a relatively low level of genetic diversity among the investigated T. asahii clinical strains.
• All five markers (IGS1, TUB1, ATP, PHCP, TOP1) collectively demonstrated potential as a molecular typing tool.

Conclusions:

• The study reveals limited genetic diversity within the T. asahii population sampled in Thailand.
• The combination of IGS1, TUB1, ATP, PHCP, and TOP1 sequences provides a viable alternative for molecular typing of T. asahii.
• This molecular typing approach can aid in investigating the population diversity and structure of T. asahii.