The Effect of Variable CO2 Concentrations on HSP70 Gene in Trichophyton Rubrum and Microsporeum Canis

Background and Objectivs: Trichophyton rubrum is considered as the most common causes of dermatophytosis in human skin and nail tissues. Microsporeum canis is a zoophile dermatophyte which can be transmited to human. HSP70 is a 70 KD heat shock protein in fungi. In this study, the effects of variable CO2 concentrations were examined on HSP70 expression in T. rubrum and M. canis. Strains used in this study were obtained from skin scales and nails of the patients who were suffering from onychomycosis. Samples were cultured on Sabouraud dextrose broth (SDB) and incubated at 25°C for 2, 4 and 7 days under 3%, 5%, and 10% of CO2 concentrations. Control cultures maintained for 7 days without CO2 concentrations. Then, RNA was isolated from the harvested mycelia mass, and HSP70 gene expression was studied in T. rubrum and M. canis by RT-PCR. The obtained results were compared to the Beta actin as a house keeping gene. The results of this study revealed the maximum variations under 3%,5%, and 10% of CO2 concentrations in maximum 7 days incubation period, and the expression of HSP70 gene showed different variations under different CO2 concentrations. Our results showed a negative effect of CO2 concentrations in the expression of HSP70 in T. Rubrum and a positive effect in M. canis comparing to the controls.