Galleria mellonella as a superficial model for Malassezia globosa and its treatment.

Introduction. Malassezia globosa is a yeast species that belongs to the mycobiota of humans and animals, associated with dermatological disorders, such as dandruff. This is a chronic scalp skin disorder characterized by flaking and itching. Treatments include commercial shampoo with different formulations that contain antifungal activities like zinc pyrithione (ZPT) or piroctone olamine (PO). The effectiveness of these formulations has been evaluated for decades for dandruff symptom relief of volunteers. To date, non-mammalian, in vivo methods exist to test formulations of these actives. Aim. To evaluate in vivo in Galleria mellonella larva, two commercial antifungal shampoos (shampoo with 1 % ZPT and 1.6 % zinc Carbonate and shampoo with 0.5 % PO) against this species. Methodology. G. mellonella larvae were inoculated with M. globosa on abraded cuticular surface. Then, integument cell viability, histological changes, and fungal burden were evaluated. Results. Larvae inoculated with M. globosa showed higher lesion melanization and tissue damage. In addition, M. globosa population showed to increase over time. Concerning the shampoo's effectiveness, both formulations significantly reduced M. globosa burden and tissue damage. Conclusion. G. mellonella larvae were allowed to evaluate M. globosa superficial infection and antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae.