Influence of trace-elements and glucose on Trichophyton rubrum grown in keratin medium

Trichophyton rubrum is a pathogenic fungus infecting human skin, hairs and nails. These substrates are low in most nutrients required for fungal growth and consequently are colonized only by very few fungal species. Especially, concentration of trace elements is low and a limiting factor for fungal growth. T. rubrum is a highly specialist fungus and adapted to this environment. By in-vitro experiments, we analyzed the influence of trace-elements on mRNA expression. We measured gene expression by RNAseq of two T. rubrum strains, STRB008 and STRB012, in three different cultivation condition, each in 6 replications. Keratin medium, without sugar supply, was used as basic medium. In the second condition, we added trace-elements to the keratin medium. In the third condition, we added glucose. We point to the evolutionary adaption of the fungus to the human skin. T. rubrum has a sophisticated system for the digestion and utilization of human skin protein and a relative low demand for trace-elements. Overall design: To analyze the influence of trace-elements on mRNA expression of Trichophyton rubrum, the fungus was pre-cultured in liquid keratin medium. Afterwards, the mycel was aliquot to keratin medium, keratin medium with trace-elements and keratin medium with glucose. After 5 days, total RNA for RNAseq has been extracted. Each condition was replicated 6 times for two fungal strains, T. rubrum STRB008 and STRB012.