Query: NC_020211:554736 Serratia marcescens WW4, complete genome
Lineage: Serratia marcescens; Serratia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This organism was discovered in 1819 by Bizio who named the organism after the Italian physicist Serrati. It was considered a nonpathogenic organism until late in the 20th century, although pathogenicity was noted as early as 1913. Serratia marcescens is an opportunistic human pathogen that is increasingly associated with life-threatening hospital-acquired infections. It is an environmental organism that has a broad host range, and is capable of infecting vertebrates and invertebrates, as well as plants. In humans, Serratia marcescens can cause meningitis (inflammation of the membrane surrounding the brain and spinal cord), endocarditis (inflammation of heart muscle) and pyelonephritis (inflammation of the kidneys). Many strains are resistant to multiple antibiotics. Environmental isolates are noted by production of the red pigment prodigiosin.
Subject: NC_008258:2100646 Shigella flexneri 5 str. 8401, complete genome
Lineage: Shigella flexneri; Shigella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This genus is named for the Japanese scientist (Shiga) who discovered them in the 1890s. They are closely related to the Escherichia group, and may be considered the same species. Shigella spp. are human-specific pathogens that are transmitted via contaminated food and water and are the leading causes of endemic bacillary dysentery, and over 1 million deaths worldwide are attributed to them. The bacteria infect the epithelial lining of the colon, causing acute inflammation by entering the host cell cytoplasm and spreading intercellularly. are extremely virulent organisms that require very few cells in order to cause disease. 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 organism, along with Shigella sonnei, is the major cause of shigellosis in industrialized countries and is responsible for endemic infections.