Pre_GI: SWBIT SVG BLASTP

Query: NC_016909:171018 Rickettsia rickettsii str. Arizona chromosome, complete genome

Lineage: Rickettsia rickettsii; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria

General Information: This genus, like other Rickettsial organisms such as Neorickettsia and Anaplasma, are obligate intracellular pathogens and is composed of two groups, the spotted fever group, and the typhus group. 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. This organism was first identified by Dr. Howard Rickets as the causative agent of Rocky Mountain Spotted Fever, which was originally named for its geographic distribution at the time, it is now known to be widespread throughout the North American continent. This bacterium is an obligate intracellular pathogen that infects primarily the vascular endothelium, and occasionally smooth muscle tissue. This bacterium is an obligate intracellular pathogen that infects primarily the vascular endothelium, and occasionally smooth muscle tissue. It is passed to the human host from a tick bite, and the tick acts as both a natural reservoir and a vector for disease transmission. Once the organism is endocytosed by the host cell, it quickly escapes the phagozome, and replicates intracellularly, causing cell death and tissue damage. The disease is characterized by a spotted rash and has a high mortality rate if left untreated.

Subject: NC_005364:1133962 Mycoplasma mycoides subsp. mycoides SC str. PG1, complete genome

Lineage: Mycoplasma mycoides; Mycoplasma; Mycoplasmataceae; Mycoplasmatales; Tenericutes; Bacteria

General Information: Causative agent of contagious pleuropneumonia in livestock. This genus belongs to the class Mollicutes (phylum Tenericutes), a taxonomic group of small (0.3-0.8 micron diameter) monoderm bacteria characterized by the lack of cell walls, reduced genome sizes, and obligate parasitic lifestyles (Krieg et al., 2010). Over 120 obligate parasitic species found in a wide spectrum of hosts, including humans, animals, insects and plants. Infection typically proceeds through the attachment of bacteria to host cells via assorted adhesins or, in some species, through highly specialized surface protein appendages. In some cases, subsequent invasion of host cells results in a prolonged intracellular persistence that may cause lethality. These adaptive strategies are involved in host cell attachment and invasion, as well as immune evasion. Although mycoplasmas are dependent on their association with eukaryotic host tissue in nature, most can be cultivated axenically if their fastidious growth requirements are met. Nearly all mycoplasmas derive energy only from glycolytic pathways, whereas some can hydrolyze arginine. Assigned to the genus Mycoplasma by historic taxonomic precedent, organism in the Mycoplasma mycoides phylogenetic cluster are in fact more closely related to other genera in the Mollicutes (Krieg et al., 2010).