Query: NC_017044:278500 Rickettsia parkeri str. Portsmouth chromosome, complete genome
Lineage: Rickettsia parkeri; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: Animal pathogen in Mammalia (intracellular obligate). Rickettsiae are obligate intracellular Gram-negative bacteria mostly found in arthropods, some of which cause mild to severe diseases in humans. Rickettsia parkeri, a member of the spotted fever group Rickettsia (SFGR), was first isolated from the Gulf Coast tick, Amblyomma maculatum, in 1937. In 2004, the first confirmed human infection with R. parkeri was reported in a 40-year-old man from the Tidewater area of coastal Virginia. The agent was isolated in cell culture from an eschar biopsy specimen and designated the Portsmouth strain; recently, the first recognized case of tick bite-associated human infection was described.
Subject: NC_011959:972798 Thermomicrobium roseum DSM 5159, complete genome
Lineage: Thermomicrobium roseum; Thermomicrobium; Thermomicrobiaceae; Thermomicrobiales; Chloroflexi; Bacteria
General Information: Thermomicrobium roseum DSM 5159 was isolated from Yellowstone National Park, USA. Obligate thermophile with unusual cell wall structure. Thermomicrobium roseum is a red-pigmented, rod-shaped, Gram-negative extreme thermophile that possesses both an atypical cell wall composition and an unusual cell membrane that is composed entirely of long-chain 1,2-diols. Analyses of environmental sequences from hot spring environments show that T.roseum displays a low quantity but ubiquitous presence in top layers of microbial mats. Few standard housekeeping genes are found on the megaplasmid, however, it does encode a complete system for chemotaxis including both chemosensory components and an entire flagellar apparatus. T. roseum oxidizes CO aerobically, making it the first thermophile known to do so. In addition, is is propose that glycosylation of its carotenoids plays a crucial role in the adaptation of the cell membrane to this bacterium's thermophilic lifestyle. Because T. roseum is a deep-branching member of this phylum, eventhough this species is not photosynthetic, analysis of the genome provides some insight into the origins of photosynthesis in the Chloroflexi.