Query: NC_010159:741819 Yersinia pestis Angola, complete genome
Lineage: Yersinia pestis; Yersinia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This strain was isolated prior to 1985 and belongs to the antiqua biovar. It can ferment rhamnonse and melibiose which is a property usually associated with Yersinia pseudotuberculosis. Strain Angola belongs to a group of atypical Yersinia pestis strains with genotypic similarities that are intermediate between Y. pestis and Y. pseudotuberuclosis strains. Genotypic studies indicate that strain Angola is the oldest Y. pestis strain analyzed to date. It carries three plasmids that are similar to other Y. pestis plasmids but have aberrant sizes. The critical virulence factor, the V antigen, is different than that encoded by typical strains of Y. pestis and there is a deletion that affects the F1 operon. Strain Angola has been shown to be virulent by aerosol in mice.
Subject: NC_003997:5200805 Bacillus anthracis str. Ames, complete genome
Lineage: Bacillus anthracis; Bacillus; Bacillaceae; Bacillales; Firmicutes; Bacteria
General Information: This well studied laboratory strain (Porton isolate) is not virulent due to the loss of the two plasmids, pXO1 and pXO2. Under starvation conditions this group of bacteria initiate a pathway that leads to endospore formation, a process that is thoroughly studied and is a model system for prokaryotic development and differentiation. Spores are highly resistant to heat, cold, dessication, radiation, and disinfectants, and enable the organism to persist in otherwise inhospitable environments. Under more inviting conditions the spores germinate to produce vegetative cells. This organism was the first to be shown to cause disease by Dr. Louis Pasteur (the organism, isolated from sick animals, was grown in the laboratory and then used to infect healthy animals and make them sick). This organism was also the first for which an attenuated strain was developed as a vaccine. Herbivorous animals become infected with the organism when they ingest spores from the soil whereas humans become infected when they come into contact with a contaminated animal. PA/LF and PA/EF complexes are internalized by host cells where the LF (metalloprotease) and EF (calmodulin-dependent adenylate cyclase) components act. At high levels LF induces cell death and release of the bacterium while EF increases host susceptibility to infection and promotes fluid accumulation in the cells.