Query: NC_003103:164972 Rickettsia conorii str. Malish 7, complete genome
Lineage: Rickettsia conorii; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: This strain was isolated from a human in South Africa. Causative agent for Rocky Mountain spotted fever. 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. This organism causes Rocky Mountain spotted fever which can cause severe damage to the endothelial layer of major organs, including the lungs, heart, kidneys, and skeletal muscle which can result in death.
Subject: NC_007413:5264463 Anabaena variabilis ATCC 29413, complete genome
Lineage: Anabaena variabilis; Anabaena; Nostocaceae; Nostocales; Cyanobacteria; Bacteria
General Information: These cyanobacteria are bluegreen algae that are capable of fixing carbon and nitrogen. They form long filaments and can be found worldwide in various aquatic environments as well as some terrestrial ones. These bacteria can form a variety of differentiated cell types, including spore-like cells (akinetes), small motile filaments (hormongia) and most importantly, heterocysts that are nitrogen-producing cells. The heterocyst produces multiple layers outside of its cell wall, shuts down photosystem II in order to inhibit oxygenic photosynthesis and ramps up metabolism in order to use up the oxygen present. Heterocysts donate fixed nitrogen compounds as amino acids to neighboring cells and in return receive a photosynthetically produced carbon source such as sucrose. These organisms produce toxic blooms in aquatic environments that are harmful or fatal to animals and humans due to the various cyanotoxins they produce. Anabaena variabilis is a filamentous heterocyst-forming cyanobacterium that fixes nitrogen and CO2 using the energy of sunlight via oxygen-evolving plant-type photosynthesis. In addition, this organism has been studied extensively for the production of hydrogen using solar energy.