Dating the Cryptococcus gattii Dispersal to the North American Pacific Northwest.

摘要: The emergence of Cryptococcus gattii, previously regarded as a predominantly tropical pathogen, in the temperate climate North American Pacific Northwest (PNW) 1999 prompted several questions. most prevalent among these was timing introduction this pathogen to novel environment. Here, we infer tip-dated estimates for three clonal C. gattii populations observed PNW, VGIIa, VGIIb, and VGIIc, based on whole-genome sequencing 134 isolates using Bayesian evolutionary analysis by sampling trees (BEAST). We estimated nucleotide substitution rate each lineage (1.59 × 10-8, 1.59 2.70 respectively) be an order magnitude higher than common neutral fungal mutation rates (2.0 10-9), indicating microevolutionary (e.g., successive generations laboratory) comparison species' slower, macroevolutionary when fossil records). nature PNW over narrow number years would therefore possibly explain our rates. Our results suggest that mean time recent ancestor all sublineages occurred within last 60 100 years. While cause dispersal is still unclear, research arrival neither ancient nor very (i.e., <25 ago), making strong case anthropogenic introduction. IMPORTANCE pathogenic fungus gattii resulted numerous investigations into epidemiological enzootic impacts, well multiple genomic explorations primary molecular subtypes were discovered. These studies lead general conclusion identified likely emerged out Brazil. conducted dating analyses determine ages various lineages seen propose hypothetical causes events. strongly suggests independent are 100 old, providing subsequent opening Panama Canal, which allowed more direct shipping between Brazil western coastline, possible driving event translocation