Pre_GI: SWBIT SVG BLASTP

Query: NC_011528:535680 Coxiella burnetii CbuK_Q154, complete genome

Lineage: Coxiella burnetii; Coxiella; Coxiellaceae; Legionellales; Proteobacteria; Bacteria

General Information: Coxiella burnetii K Q154 was isolated from a patient with endocarditis and contains the plasmid QpRS. 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.

Subject: NC_006368:3211998 Legionella pneumophila str. Paris, complete genome

Lineage: Legionella pneumophila; Legionella; Legionellaceae; Legionellales; Proteobacteria; Bacteria

General Information: This serogroup I strain is endemic in France. Causes Legionnaire's disease. This organism is a non-marine bacterium usually found growing inside other organisms such as protozoans in aquatic environments. They can also be found in soil, freshwater, and in biofilms. The first outbreak of Legionnaire's disease occurred in 1976 at an American Legion convention and the resulting pneumonia-like disease resulted in 34 deaths. The cause of the disease was traced to Legionella bacteria. Once the bacteria are brought into the lungs they make contact with alveolar macrophages and are internalized where they can cause severe respiratory distress. Internalization occurs through specialized vacuoles (replicative phagosomes) that allow the bacteria to grow and replicate prior to escape from the macrophage. Formation of the replicative phagosome, which requires reprogramming of the normal phagosome maturation pathway, requires a type IV secretion system called the Dot/Icm system. This type IV system is closely related to the conjugative system of plasmid ColIb-P9, and is involved in the secretion of numerous protein components that aid in formation of the replicative phagosome. Other virulence determinants include a set of multidrug transporters and other efflux pumps for toxic compounds that may allow the organism to persist in its habitat, a set of LPS phase variable genes that enhance immune evasion, and a type II secretion system for transport of hydrolases.