Query: NC_007205:841818 Candidatus Pelagibacter ubique HTCC1062, complete genome
Lineage: Pelagibacter ubique; Pelagibacter; Pelagibacteraceae; Rickettsiales; Proteobacteria; Bacteria
General Information: They were originally named SAR11 and known only from their rRNA genes, which were first identified in environmental samples from the Sargasso Sea in 1990. P. ubique are possibly the most numerous bacteria in the world.
Subject: NC_006142:811469 Rickettsia typhi str. Wilmington, complete genome
Lineage: Rickettsia typhi; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: This genus, like other Rickettsial organisms such as Neorickettsia and Anaplasma, is composed of obligate intracellular pathogens. The latter is composed of two organisms, Rickettsia prowazekii and Rickettsia typhi. The bacteria are transmitted via an insect, usually a tick, to a host organism, in this case humans, where they target endothelial cells and sometimes macrophages. They attach via an adhesin, rickettsial outer membrane protein A, and are internalized where they persist as cytoplasmically free organisms. Transovarial transmission (from mother to offspring) occurs in the invertebrate host. Rickettsia typhi causes murine typhus and is an obligate intracellular pathogen that infects both the flea vector and hosts such as human, rat, and mouse. In the flea vector, the bacterium penetrates the gut epithelial barrier and is found in the feces which become infective.