Query: NC_007517:687276 Geobacter metallireducens GS-15, complete genome
Lineage: Geobacter metallireducens; Geobacter; Geobacteraceae; Desulfuromonadales; Proteobacteria; Bacteria
General Information: First isolated from the Potomac river downstream of Washington, DC, USA in 1987. This organism actively moves towards metal attractants such as iron and manganese oxides, which are insoluble, and produces type IV pili for attachment to the insoluble substrates. Common metal-reducing bacterium. This organism, similar to what is observed in Geobacteria sulfurreducens, couples the oxidation of organic molecules to the reduction of iron by using insoluble Fe (III) as an electron acceptor under anaerobic conditions. This bacterium plays an imporant part of the nutrient cycling in aquatic environments. The cell can also use uranium and plutonium, therefore, this organism and may be important for the bioremediation of contaminated waste sites.
Subject: NC_010117:285230 Coxiella burnetii RSA 331, complete genome
Lineage: Coxiella burnetii; Coxiella; Coxiellaceae; Legionellales; Proteobacteria; Bacteria
General Information: This strain (RSA 331; Hentzerling) is associated with acute Q fever and was isolated from the blood of an infected patient in northern Italy in 1945. This organism is widely distributed in nature and can cause infections in reptiles, birds, and mammals. It causes Q fever, or 'query' fever, an atypical pneumonia first associated with abattoir workers in Australia. Transmission may be through insect vectors such as ticks that have bitten an infected wild or domesticated animal, or through an aerosol produced by domesticated animals such as sheep or cattle. The presence of a plasmid is believed to be associated with virulence and pathogenicity, however C. burnetii isolates containing plasmid QpDG are avirulent in guinea pigs and plasmidless isolates have been associated with endocarditis in humans. Coxiella burnetii has a developmental life cycle, and can grow vegetatively through binary fission, or asymmetrically and produce a spore-like cell. The spore-like cell may enable the organism to exist extracellularly for small amounts of time. This bacterium is an obligate intracellular pathogen. It is endocytosed by a host cell, a macrophage for example, and lives and replicates inside the phagolysozome, a unique property of this organism. The genome encodes proteins that have a higher than average pI, which may enable adaptation to the acidic environment of the phagolysozome. The chromosome also contains genes for a number of detoxification and stress response proteins such as dismutases that allow growth in the oxidative environment. The type IV system is similar to the one found in Legionella, which may be important for intracellular survival. This organism produces numerous ankyrin-repeat proteins that may be involved in interactions with the host cell. The genome has 83 pseudogenes, which may be a result of the typical genome-wide degradation observed with other intracellular organisms and also has a group I intron in the 23S ribosomal RNA gene.