Query: NC_008150:844727 Yersinia pestis Antiqua, complete genome
Lineage: Yersinia pestis; Yersinia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: Isolated from a soil sample from the Republic of Congo. Causative agent of plague. Specific virulence factors are encoded within pathogenicity islands (PAIs) that are required for the invasive phenotype associated with Yersinia infections. One key virulence plasmid contained by the three human-specific pathogens is pCD1/pYv, which encodes a type III secretion system for the delivery of virulence proteins that contribute to internalization into the host cell. It is the causative agent of plague (bubonic and pulmonary) a devastating disease which has killed millions worldwide. The organism can be transmitted from rats to humans through the bite of an infected flea or from human-to-human through the air during widespread infection. Yersinia pestis is an extremely pathogenic organism that requires very few numbers in order to cause disease, and is often lethal if left untreated. The organism is enteroinvasive, and can survive and propagate in macrophages prior to spreading systemically throughout the host. Yersinia pestis consists of three biotypes or serovars, Antiqua, Mediavalis, and Orientalis, that are associated with three major pandemics throughout human history. pMT1 encodes a protein, murine toxin, that aids rat-to-human transmission by enhancing survival of the organism in the flea midgut. Yersinia pestis also contains a PAI on the chromosome that is similar to the SPI-2 PAI from Salmonella that allows intracellular survival in the organism.
Subject: NC_010660:86445 Shigella boydii CDC 3083-94 plasmid pBS512_211, complete sequence
Lineage: Shigella boydii; Shigella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This strain (strain BS512; serotype 18) was originally isolated from a 12-year-old boy in Arizona, USA by Dr. Nancy Stockbine. It is a member of Group 1 as determined by limited sequence analysis and can invade HeLa cells. Pathogenicity and virulence have been verified during in vitro experimentation, and multiple plasmids are present in this strain. This genus is named for the Japanese scientist (Shiga) who first discovered these organisms in the 1890s. They are closely related to the Escherichia group, and may be considered the same species. These organisms are human-specific pathogens that are transmitted via contaminated food and water and are the leading causes of endemic bacillary dysentery, causing over 160 million cases of infection and 1 million deaths yearly worldwide. The bacteria infect the epithelial lining of the colon, causing acute inflammation by entering the host cell cytoplasm and spreading intercellularly. Shigella spp. are extremely virulent organisms that can cause an active infection after a very low exposure. Both the type III secretion system, which delivers effector molecules into the host cell, and some of the translocated effectors such as the invasion plasmid antigens (Ipas), are encoded on the plasmid. The bacterium produces a surface protein that localizes to one pole of the cell (IcsA) which binds to and promotes actin polymerization, resulting in movement of the bacterium through the cell cytoplasm, and eventually to neighboring cells, which results in inflammatory destruction of the mucosal lining. This species is uncommon except in India, where it was first isolated. Progression to clinical dysentery occurs in most patients infected with this organism.