In vitro models of Batrachochytrium dendrobatidis strains infections from Brazil

Abstract

Chytridiomycosis, an emergent infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), is considered one of the drivers of the current amphibian diversity loss. Regarding the impact of Bd on the amphibian host, infections can lead to antagonistic effects due to the induction of epidermal hyperplasia, hyperkeratosis, and increased sloughing rates, ultimately leading to disruptions of essential homeostatic functions. Despite the number of in vivo experiments with Bd infection in Brazilian anurans, knowledge about the early infection process at a cellular level is still limited. The genus Melanophryniscus is considered an important group for conservation efforts and occurs mainly in the south of Brazil, where feral populations of bullfrogs are widespread. As some species of Melanophryniscus are endangered, the presence of bullfrogs in natural environments represents a risk, given that bullfrogs can carry high Bd infection loads without developing chytridiomycosis. Also, Bd-ASIA-2/BRAZIL, a high virulent strain occurs in the south and might be a concern to endangered species. Therefore, we propose to analyze the entire Bd colonization cycle of Bd/GPL isolate from the bullfrog, and of BdASIA-2/BdBRAZIL strain, by modeling the in vitro infection in the continuous A6 cell line. After learning the cell-based assay that mimics the colonization stages of Bd, these techniques may facilitate the future mechanistic studies of host susceptibility and pathogen virulence in anurans from Brazil. (AU)