Whole-genome resequencing of Trichophyton rubrum provides insights into population differentiation and drug resistance.

Trichophyton rubrum (T. rubrum) is anthropophilic fungus and thus a very common cause of dermatophyte infections around the world. Infection of T. rubrum could result in conditions such as tinea capitis, tinea corporis, tinea inguinalis, tinea manus, tinea unguium, or tinea pedis. Because of this, the resistance of T. rubrum to antifungal therapies has drawn extensive research interest. However, the pathogenic characteristics of T. rubrum, such as site of infections, geographic location and host groups, have yet to be explored. In this study, the whole genome of 48 strains from different regions is resequenced and the population structure and association of single nucleotide polymorphism with resistance to six widely used antifungal drugs are analyzed. A total of 23,394 genomic variations are detected, which cover 2165 genes with only 15.14% of the variations located in exons. The population structure of T. rubrum is monomorphic, and genetic diversity is very low. Population structure analysis shows that the 48 sampled strains can be divided into two sub-populations. The gene TERG_08771 harboring the highest SNPs density is found to be associated with resistance to voriconazole. Although many proteins have yet to be identified and explored, association studies could still be useful to identify drug resistance or drug-susceptible loci, which would warrant further insightful investigations.