Which statement is true about an exotoxin?
A. It is commonly produced by gram negative bacteria
B. Its 50% lethal dose may be as low as the picogram level
C. It is composed primarily of carbohydrate
D. It is LPS associated
E. It is heat stable
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Biological products commonly used for passive immunity are
A. killed bacterial cells
B. the vaccine
C. BCG
D. toxoid
E. antitoxin
The pathogenicity of bacteria mainly depends on bacterial
A. basic and special structures
B. catabolites
C. invasiveness and toxins
D. ways to invade the body
E. number of invading bacteria
Which of the following statements about lipopolysaccharide is correct?
A. It interacts with macrophages and monocytes yielding release of cytokines
B. The toxic component is the O side chain
C. It forms holes in red blood cell membranes yielding hemolysis
D. It causes hypothermia
E. It causes paralysis
Which of the following best describes the mechanism of actionof diphtheria toxin?
A. Forms pores in red blood cells causing hemolysis
B. Degrades lecithin in eukaryotic cell membranes
Causes release of tumor necrosis factor
D. Inhibits elongation factor 2
E. Causes increased adenylate cyclase activity
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