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Infectious agent transmission bacteria

The abnormal deposits found in the brains of CJD victims consist of an abnormal isoform of PrP. Prion protein is normally found in cells. Detailed structural studies show that normal cellular PrP (PrP ) is a soluble protein whose conformation is rich in a-helices with very little P-sheet. The PrP protein extracted from the brains of CJD victims (i.e., PrP ) is identical in primary amino acid sequence to the normal PrP (PrP ). However, PrP has a much greater content of P-sheet conformation with little a-helical structure. Thus PrP is neurotoxic because of its three-dimensional structure. When the prion protein is predominantly in an a-helical conformation it is nontoxic when the prion protein is predominantly in a P-sheet conformation, it kills neurons. The prion protein is thus made neurotoxic not by its amino acid composition but by its conformation. This concept is both fascinating and terrifying. Prion diseases are transmissible thus prions are infectious agents. However, prions are not like bacteria or viruses, or other infectious microbes—they are simply protein molecules. Prions are not microbes with cell membranes and nucleic acids they are not living things. Indeed, prions are not even infectious molecules, they are infectious molecular shapes. [Pg.514]

Common definitions of the term disinfection usually aim at its medical aspects related to transmissible diseases and to the killing or irreversible inactivation of the disease-causing organisms by use of chemical agents or physical procedures. This includes the destruction of infectious or other undesirable bacteria, pathogenic fungi or vimses and protozoa on surfaces or any inanimate objects (Block, 1993, Harke, 1987). Thus, disinfection of water, air or surfaces should produce a... [Pg.279]


See other pages where Infectious agent transmission bacteria is mentioned: [Pg.456]    [Pg.1095]    [Pg.1160]    [Pg.353]    [Pg.3]    [Pg.55]    [Pg.118]    [Pg.291]    [Pg.167]    [Pg.296]    [Pg.55]    [Pg.140]    [Pg.159]    [Pg.16]    [Pg.16]    [Pg.42]   
See also in sourсe #XX -- [ Pg.495 ]




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