Molecular Phylogeny of Babesia poelea From Brown Boobies (Sula leucogaster) From

The phylogenetic relationship of avian Babesia with other piroplasms remains unclear, mainly because of a lack of objective cri- teria such as molecular phylogenetics. In this study, our objective was to sequence the entire 18S, ITS-1, 5.8S, and ITS-2 regions of the rRNA gene and partial s-tubulin gene of B. poelea, first described from brown boobies (Sula leucogaster) from the central Pacific, and compare them to those of other piroplasms. Phylogenetic analyses of the entire 18S rRNA gene sequence revealed that B. poelea belonged to the clade of piroplasms previously detected in humans, domestic dogs, and wild un- gulates in the western United States. The entire ITS-1, 5.8S, ITS-2, and partial s-tubulin gene sequence shared conserved regions with previ- ously described Babesia and Theileria species. The intron of the s- tubulin gene was 45 bp. This is the first molecular characterization of an avian piroplasm.