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_005956:1572500 Bartonella henselae str. Houston-1, complete genome

Lineage: Bartonella henselae; Bartonella; Bartonellaceae; Rhizobiales; Proteobacteria; Bacteria

General Information: Bartonella henselae str. Houston-1 (ATCC 49882) was isolated from human blood in Houston Texas. Causative agent of cat scratch fever. This group of alpha proteobacteria are unique among pathogens in that they cause angiogenic lesions. This organism was identified as the causative agent of cat scratch fever, a disease found commonly in children or in immunocompromised adults. The proliferation of the vascular endothelium (bacillary angiomatosis) is characterisitic of Bartonella infection and results in multiplication of the bacterium's host cells. Infected macrophages are stimulated to release vascular endothelial growth factor (VEGF) and interleukin 1 beta, both of which promote angiogenesis. Endothelial cells are also stimulated to grow and divide by direct contact with bacterial cells. In addition, programmed cell death (apoptosis) of endothelial cells is inhibited, combatting a common mechanism eukaryotic cells use to deal with bacterial infection. Other pathogenicity factors include pili and outer membrane adhesins for attachment to host cells.