Genomic characters of and genetic diversity in China.

The emergence of or -like infection in humans from China and the United States of America has raised concern about the public health importance of this pathogen. Although has been detected in a wide range of ticks and mammals in the world, no genome of the pathogen is available up to now, which has prohibited us from better understanding the genetic basis for its pathogenicity. Here we describe an genome from metagenomic sequencing of an infected goat in China. had the smallest genome of the genus , and relatively lower GC content. Phylogenetic analysis of single-copy orthologue sequence showed that was closely related to and , but relatively far from intraerythrocytic species. had 116 unique orthogroups and lacked 51 orthogroups in comparison to other species. The virulence factors of were significantly less than those of , suggesting less pathogenicity of . When tested by specific PCR assays, was detected in 23 of 29 goats, with an infection rate up to 79.3% (95% CI: 64.6% ∼94.1%). The phylogenetic analyses based on partial 16S rRNA, and genes indicated that had high genetic diversity. The findings of this study lay a foundation for further understanding of the biological characteristics and genetic diversity of , and will facilitate the formulation of prevention and control strategies.