Experimental study of the removal of Candida albicans from mouse tongues using photoactivated disinfection

To establish a mouse model of acute pseudomembranous stomatitis and to observe the effect of photoactivated disinfection (PAD) on the removal of Candida albicans in vivo, and initially explore the feasibility of this technology in the treatment of acute pseudomembranous stomatitis.

Six-week-old male ICR mice were selected and immunized with 1 × 10⁷ CFU/mL Candida albicans solution on the backs of the tongues of immunosuppressed mice. Thirty model mice with acute pseudomembranous stomatitis were successfully established and randomly divided into a control group and a photoactivated disinfection group, with 15 mice in each group. Mice in the photoactivated disinfection group were coated with 1 mg/mL toluidine blue solution on the back of the tongue, incubated for 1 min and irradiated with 750 mW LED red light for 1 min. Immediately after treatment, the tongue fungal load was measured in the photoactivated disinfection group and the control group. Tongue fungal load was measured again 48 h later, and tongue histopathological examination was performed in both groups.

Forty-eight hours after PAD treatment, the white pseudomembrane on the back of the tongue in the photoactivated group was significantly less than the control group. The fungal load on the dorsum of the tongue in the treatment group was significantly lower than the control group immediately and 48 h after treatment for PAD, and the difference was statistically significant (P < 0.05). Forty-eight hours after PAD treatment, HE staining showed that the epithelial structure of the PAD group was more regular than the control group, and no microabscesses were observed. PAS staining showed that the number of mycelia in the PAD group was significantly less than the control group. Mycelia occasionally invaded the keratinized layer but did not penetrate into the upper cortex.

PAD significantly removed Candida albicans from the tongues of mice with acute pseudomembranous Candida stomatitis.