Diverse Lineages of Live on Old Oaks.

The human pathogen is considered an obligate commensal of animals, yet it is occasionally isolated from trees, shrubs, and grass. We generated genome sequence data for three strains of that we isolated from oak trees in an ancient wood pasture, and compared these to the genomes of over 200 clinical strains. strains from oak are similar to clinical in that they are predominantly diploid and can become homozygous at the mating locus through whole-chromosome loss of heterozygosity. Oak strains differed from clinical strains in showing slightly higher levels of heterozygosity genome-wide. Using phylogenomic analyses and chromosome painting, we show that each oak strain is more closely related to strains from humans and other animals than to strains from other oaks. The high genetic diversity of from old oaks shows that they can live in this environment for extended periods of time.