Pathogenicity study of ascomycetous opportunistic yeasts from fresh feces of pigeons using Tenebrio molitor larvae as a host model.

The choice of model to assess host-pathogen interactions is crucial for the analysis of microbial pathogenicity. Insects are increasingly chosen as model hosts for the study of microbial infections. Although the immune system responses of insects are not specific, they have a complex, evolutionarily conserved innate immune system with cellular and humoral elements. In this study, we investigated in vivo the virulence of potentially pathogenic ascomycetous yeasts found in fresh feces of street pigeons using the larval host model of Tenebrio molitor. The results were arranged in survival curves according to the Kaplan-Meier method. The yeasts Arxiozyma bovina showed the highest pathogenicity, resulting in a significantly shortest median survival time - 24 h, followed by Nakaseomyces glabratus (4 days), Candida albicans and C. tropicalis (5 days), Clavispora lusitaniae (6 days), C. parapsilosis and Pichia kudriavzevii (7 days). The T. molitor model demonstrated the pathogenic potential and virulence differences of the ascomycetous yeasts observed in fresh pigeon droppings in the city. It provided a valuable, swift and cost-effective tool for preliminary virulence screening of clinically important yeasts spread by synanthropic birds in the anthropophized areas. Its detection is of key importance for immunocompromised people and children and is in line with the One Health approach.