Mastering Microbiology Chapter 15

They are able to detect structures on the surfaces of foreign cells that are not found in the host.

The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.

Tuberculosis bacterium

It can change the surface antigens frequently, preventing the immune system from tracking it.

Molecules that are capable of destroying phagocytes

suppressing the immune system.

Neisseria species.

They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.

Capsules block the complement biding sites on the surface of the pathogen.

lipid A

When the cell dies

fever

It can lower blood pressure and cause the patient to go into shock

cytotoxin

b domain

Superantigens cause an overstimulation of the host immune system.

superantigen

neurotoxin

An individual contracts hepatitis B from an accidental stick with a contaminated needle

to ensure that a sterilized medical device is free of endotoxin

cholera

Exotoxin production by bacteria is frequently the result of a lysogenic infection.

-gaining access to the host via a portal of entry -adherence to host tissues -evasion of host defenses

-Exotoxins target specific cellular structures or molecules. -Exotoxins are protein molecules. -Very small amounts of exotoxin can be lethal.

-Some pathogens are able to cause disease within a host without penetrating the body. -Bacterial exotoxins can be altered to create toxoids, which can be used to produce protective immunity in a host. -The interactions that occur between a microbe and host influence the evolution of both

This viscous outer covering found in certain microorganisms helps pathogens evade the host 19s defenses by impairing phagocytosis

These structures contain substances that contribute to a pathogen 19s virulence; for example, M protein mediates microbial attachment to epithelial cells.

These proteins contribute to a pathogen 19s virulence by, for example, forming and breaking down fibrin clots, breaking down connective proteins, and countering certain types of antibodies.

This process allows pathogens to alter their surface antigens to avoid attack by antibodies produced by the immune system.

These microbial surface proteins rearrange the host cell 19s actin filaments, allowing pathogens to enter and move in and between cells.

These proteins bind up iron obtained from the host cell 19s iron-transport proteins and transport this iron to bacteria through interactions with cell surface receptors.

This occurs as a result of nutrient depletion, accumulation of waste products, pathogen entry and exit, and ruptured host cells

these poisonous substances cause most of the damage to host cells; they can be transported by the blood or lymph and may produce far-reaching effects

This results in a change in microbe characteristics due to the presence of prophage genes that confer new properties

These describe the visible effects of viral infections that results in host cell damage.

-blocking host cell receptors to which A-B toxins bind -blocking receptor-mediated endocytosis in cells targeted by the A-B toxin -inhibiting the secretion of proteins from a bacterial cell -blocking separation of the A and B components of the toxin -blocking the binding sites on the B portion of an A-B toxin-

-blocking molecular determinants on superantigens that interacts with T cells -blocking the release of cytokines from T cells -blocking secretion of proteins by bacterial cells -neutralizing circulating cytokines

gram-negative bacterial infections.

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