Evaluating the effects of Low Level diode lasers 685, 830 nm on the growth of Trichophyton rubrum: an In-Vitro study.

Trichophyton rubrum is one of the major causes of dermatophytosis both in the world and in Iran. Trichophyton rubrum invades keratinized tissues (hair, skin and nails) of humans and animals. Dermatophytosis is recurrent and drug-resistant. Furthe more, it often needs expensive treatmens. In a search about new treatment modalities alongside conventional drug therapies in order to achieve a better control for dermatophytosis, we studied the effect of Low Level Laser Therapy(LLLT) using diode laser (685 and 830 nm) on Trichophyton rubrum in an in-vitro setting.

In this in-vitro study,at first we identified T.rubrum using standard methods. Then equal amounts of T.rubrum were cultured on Sabouraud Dextrose Agar with Chloramphenicol and Cyclohexamide (Scc) plates. Afterwards,the plates were irradiated in 9 group using Diode laser(BTL 2000) 685 nm (25 mW; 3,5,10,20 J/Cm2)and 830 nm (200mW;3,5,10,30,50 J/Cm2). In each group 12 plates were irradiated. Also 12 plates served as control group. Then plates were examined for inhibition of growth, macroscopic and microscopic morphology, minimum inhibitory concentrations (MIC) and genomic changes following exposure.

The results of this study indicated that the fungal growth were observed in all groups, but LLLT is effective on quality of growth of Trichophyton rubrum in a dose dependent manner. All these changes were obvious in laser groups irradiated by 685 nm and 830 nm at a fluencies ≥ 10 J/cm2. The most changes were observed at the fluence 20 J/CM2 (685nm) and 30 J/CM2 (830 nm). (p<0/001).

In this study, LLLT didn’t inhibit the fungal growth, but changes in the quality of growth of Trichophyton rubrum imply that LLLT h effects on the T.rubrum independently, and these changes probably occur on the protein synthesis level and gene expressions.