Query: NC_017514:2096452 Neisseria meningitidis M01-240149 chromosome, complete genome
Lineage: Neisseria meningitidis; Neisseria; Neisseriaceae; Neisseriales; Proteobacteria; Bacteria
General Information: The second of two pathogenic Neisseria, this organism causes septicemia and is the leading cause of life-threatening meningitis (inflammation of the meninges, the membrane surrounding the brain and spinal cord) in children. This organism typically residies in the nasopharynx cavity but can invade the respiratory epthelial barrier, cross into the bloodstream and the blood brain barrier, and cause inflammation of the meninges. Pathogenicity factors include the surface proteins (porins and opacity proteins), and the type IV pilus (which is also found in Neisseria gonorrhoeae). This organism, like Neisseria gonorrhoeae, is naturally competent, and protein complexes at the cell surface recognize the uptake signal sequence in extracellular DNA, an 8mer that is found at high frequency in Neisseria chromosomal DNA.
Subject: NC_010628:6165632 Nostoc punctiforme PCC 73102, complete genome
Lineage: Nostoc punctiforme; Nostoc; Nostocaceae; Nostocales; Cyanobacteria; Bacteria
General Information: The strain was isolated from a symbiotic association with the gymnosperm cycad Macrozamia sp. It typically grows in freshwater habitats. This genera of cyanobacteria are typically terrestrially-associated and are especially found in limestone or nutrient-poor soils. They are very similar to Anabaena spp. and historically they have been distinguished on the basis of morphological and life cycle characteristics. Nostoc spp. can grow heterotrophically or photoheterotrophically, and form heterocysts for nitrogen fixation. This organism can form nitrogen-fixing symbiotic relationships with plants and fungi such as the bryophyte Anthoceros punctatus. The relationship is relatively simple as compared to the Rhizobial symbiotic relationship. In the presence of the plant, hormogonia (short motile filaments) infect the plant, and then form long heterocyst-containing (nitrogen-fixing differentiated bacterial cells) filaments. The bacterial cell receives carbon sources in exchange for fixed nitrogen.