Submitted to: Journal of Biological Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/9/1999
Publication Date: N/A
Citation: Interpretive Summary: Swarming migration is a type of bacterial movement that contributes to the ability of many gram-negative bacteria such as Salmonella to cause disease. Proteus mirabilis is one of the organisms that undergoes swarming consistently, and thus researchers have used it as a model system to understand how cells change into swarm cells. These cells are different from normal cells because they are nearly 30 times longer, produce 10 to 5 times more flagella that are required for bacterial locomotion, and produce more virulence factors such as toxins that lyse red blood cells.The objective of this research was to characterize a capsule that Proteus must produce in order to swarm. Results describe the structure of an acidic capsule. When compared to results from other species of Proteus and distantly related organisms such as Salmonella and Shigella, it appears that each gram-negative genus uses a different type of carbohydrate to facilitate movement and pathogenesis. These results have implications for the design of gram-negative vaccines in general.
Technical Abstract: Swarming by Proteus mirabilis is characterized by cycles of rapid and coordinated population migration across surfaces following differentiation of vegetative cells into elongated hyperflagellated swarm cells. It has been shown that surface colony expansion by the swarm cell population is facilitated by a colony migration factor (Cmf), a capsular polysaccharide (CPS) which also contributes to the uropathogenicity of P. mirabilis [Gygi et. al. (1995) Mol. Microbiol. 17, 1167-1175]. In this report, the Cmf-CPS was extracted with hot water, precipitated with ethanol, and further purified by gel permeation chromatography. Its structure was established by glycosyl composition and linkage analyses, and by 1-D and 2-D NMR spectroscopy. The Cmf-CPS is composed of tetrasaccharide repeating unit.