The Causitive Agent of Rocky Mountain Spotted Fever Essay -- Biology M

The Causitive Agent of Rocky Mountain Spotted FeverThe Bacteria Rickettsia rickettsii is the small, aerobiotic gram-negative bacterium that is the cause Rocky Mountain spotted pyrexia in humans (and other vertebrates). They are obligate, intraelectric cellular bacteria that prune in size form 0.2x0.5 m to 0.3x2.0m. Rickettsia belong to the phylum alpha-protobacteria, which are unresolved of growing in low levels of nutrients, and have a long extension time relative to other gram negative bacteria such as Escherichia coli. In humans rickettsiae preferentially reside in the effect or cytoplasm of cells lining small to medium size blood vessels.Rickettsia enter soldiers cell by inducing phagocytosis, then straightaway escape the phagosome to grow and reproduce within the cytoplasm (or nucleus)of the force cell. The host cell will normally lyse eventually, causing the release of new-made organisms. The host cell is also harmed by the toxic effect of the cell wall. (CDC) van Ki rk et al have done studies showing that actin-based motility (ABM) is a instrument for intercellular spread. R. rickettsii is the only Rickettsia species that utilizes ABM. Findings suggest that ABM is a major means in causing infection after a host cell becomes infected the polymerization of the actin of the host cell forms a filamentous actin comet drag. The actin tail aids the pathogen in moving through the cytosol and into membrane protrusions of the host cell, where it fire be engulfed by neighboring cells and can initiate a new infectious cycle.The vector Rocky Mountain spotted fever (RMSF) is categorise as a zoonosis (diseases of animals that can be transmitted to humans), and requires a vector for transmission. The vectors (and reservoirs) for RMSF are tic... ...G. Marshall, Anita M Kelsey, MD. Whats Your Diagnosis? Consultant venerable 19961729-1735Niebylski, Mark L., Mort G. Peacock, and Tom G. Schwan. Lethal Effect of Rickettsia rickettsii on Its Tick Vector (Derm acentor andersoni) Applied and Environmental Microbiology Feb 1999 p 773-338.Rahman, M. Sayeedur, Jason A. Simser, Kein R. Macaluso, and Abdu F. Azad. Molecular and Funcional Analysis of the lepB Gene, Encoding a Type I Signal Peptidase from Rickettsia rickettsii and Rickettsia typhi. Journal of Bacteriology August 2003 (2003 American Society for Microbiology)4578-4584.Van kirk, Levi S., Stanley F. Hayes, and Robert A. Heinzen. Ultrastructure of Rickettsia rickettsii Actin Tails and Localization of Cytoskeletal Proteins. Infection and Immunity (August 2000). Abstract. 16 September 2004. .