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Micro Final

Terms in this set (234)

When a child begins to get its first teeth, what happens to the microbiota in the oral cavity?

The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms in the gingival crevices.
The teeth are rapidly colonized by aerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
The teeth are rapidly colonized by obligate anaerobes, in particular Fusobacterium, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
Which of the following features of Salmonella prevent it from being phagocytosed?

Fimbriae
Flagella
Invasins
Flagella
Where do Salmonella pathogens grow and replicate in the infected host?

Inside intestinal epithelial cells
Inside M cells
Inside phagocytes
Inside Shigella cells
Inside phagocytes
Where is the site of Shigella attachment in the host?

Leukocytes
Intestinal epithelial cells
Phagocytes
M cells
M cells
How do Shigella cells move between host cells?

They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.
They are secreted by phagocytes.
They lyse the M cell, releasing thousands of new cells to infect other host cells.
They are secreted directly into the epithelial cells from the M cells.
They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another
What is the etiologic agent of typhoid?

E. coli
Salmonella
Shigella
Salmonella
What are leukocidins?

Molecules that are capable of destroying phagocytes
Molecules that can degrade IgA
Molecules that destroy the complement proteins
Molecules that are capable of destroying phagocytes
Measles viruses are capable of inactivating host defenses by

producing superantigens.
producing leukocidins.
destroying complement proteins.
suppressing the immune system.
suppressing the immune system.
Meningitis and gonorrhea are caused by

measles virus.
Neisseria species.
Pseudomonas species.
Neisseria species.
How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system?

They cause the immune system to turn on itself.
They cause the immune system to destroy IgA antibodies.
They cause fever, which destroys the complement proteins.
They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
How can capsules enable bacteria to evade the immune system?

Capsules can bind up IgA, rendering it inactive.
A capsule is a superantigen that distracts the immune system.
Capsules block the complement biding sites on the surface of the pathogen.
Capsules block the complement biding sites on the surface of the pathogen.
An exotoxin that has the ability to kill or damage host cells is referred to as a(n)

A-B toxin.
neurotoxin.
superantigen.
enterotoxin.
cytotoxin.
cytotoxin
Which domain of the A-B toxin binds to cell surface receptors on the host cell?

Both the A and B domains have the ability to bind to cell surface receptors.
A domain
A-B toxins do not bind to cell surfaces.
B domain
B domain
How are superantigens different from other types of exotoxins?

Superantigens are comprised of two functional domains.
Superantigens must be endocytosed into a target cell before becoming active.
Superantigens only act against host neurons.
Superantigens cause an overstimulation of the host immune system.
Superantigens cause an overstimulation of the host immune system.
A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n)

membrane disrupting toxin.
cytotoxin.
enterotoxin.
superantigen.
superantigen.
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