In Vitro Infection Model Using A6 Cells Sets the Stage for Host-Batrachochytrium salamandrivorans Exploration.

The chytrid fungus Batrachochytrium salamandrivorans (Bsal) poses a significant threat to amphibian biodiversity, driving severe declines in salamander populations in Europe. While understanding the host-pathogen interaction may yield novel avenues for disease mitigation, effective in vitro models are currently lacking. We here develop a cell-culture-based model using A6 cells to reproduce the complete life cycle of Bsal in vitro, encompassing key stages such as β-galactose-associated cell attachment, active host cell penetration, intracellular maturation, host cell death, and Bsal release. Using imaging techniques, we provide evidence that Bsal penetrates A6 cells through a mechanism independent of conventional host actin dynamics. Our comparative analysis reveals that Bsal infection closely mirrors responses observed in native salamander skin tissues, validating the A6 cell line as an effective surrogate for in vivo studies. This research enhances our understanding of Bsal's pathogenicity and emphasizes the potential of the A6 cell model for future studies.