Influence of environmental temperature on the phenotypic variation of Batrachochytrium dendrobatidis isolates from Mexico.

Chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is a major emerging disease contributing to the global decline of amphibians. Phenotypic variations in Bd, such as zoosporangia size and zoospore production, may be linked to differences in pathogenicity among isolates and adaptation to temperatures. Bd has been detected in various regions in Mexico, but its phenotypic variability and relationship to pathogenicity remain unexplored. Here, we examine phenotypic characteristics of Bd such as the growth rate, carrying capacity, zoospore production, and zoosporangia size of ten Bd isolates representing different sublineages within the Bd Global Panzootic Lineage, collected from diverse temperature regimes in Mexico. We found high phenotypic variability between isolates, with growth rate and zoosporangia size influenced by the environmental temperature of their respective sites. Other traits, such as carrying capacity and zoospore production, did not show clear patterns related to environmental temperature. Our findings provide insights into the phenotypic variability of Bd in Mexico and highlight the complexity of pathogen-environment interactions suggesting local adaptations.