Section 19.10 Endotoxins are lipopolysaccharides derived from the Gram-negative Bacteria. Released upon lysis of the Bacteria, endotoxins cause systemic toxic effects such as fever in the host. Endotoxins are not as toxic as most exotoxins. The invasiveness and toxigenicity of a pathogen determine virulence. In most pathogens, a number of factors contribute to virulence.
Attenuation is loss of virulence.
Explain how an organism may become attenuated. Define the role of attenuated organisms in vaccine production. Section 19.12 Nonspecific physical, anatomical, and chemical barriers prevent colonization of the host by most pathogens. Breakdown in these defenses results in a compromised host who is more susceptible to infection. Section 19.13 Inflammation and fever are nonspecific responses to noxious stimuli, such as pathogens.