Host microbe interactions
Which of the following is an example of a beneficial host-microbe interaction?
a. Influenza virus avoids antibodies when their antigens change
b. The normal microbiota of the skin prevents growth of other microbes
c. Antibiotic therapy can allow C. difficile to grow in the intestine
d. Some people carry Staphylococcus aureus bacteria in the nose
b. The normal microbiota of the skin prevents growth of other microbes
Microbicidal effects
a. do not kill but will slow or completely stop
microbial reproduction or replication
b. compete with nearby cells for nutrients and resources
c. slow down bacterial growth enough that the
immune system can catch up
d. will kill microbes
d. will kill microbes
T or F
Environmental reservoirs do not
have portals of exit
True
Endotoxins are typically
a. made in the microbial cell and targets the
intestines
b. made in the microbial cell and
secreted into environment
c. part of the cell’s structures and released when the cell dies
d. made in the microbial cell and targets the heart
c. part of the cell’s structures and released when the cell dies
antigenic masking is when...
a. pathogens have receptors that bind to host self-antigens
b. antigens on the surface of the microbe are similar at the molecular level to antigens in the host
c. pathogens mutate rapidly so that their antigens have a different structure each time you are infected
d. antibodies against its antigens swaps
between different antigens on its surface
a. pathogens have receptors that bind to host self-antigens
The normal microbiota protect us using a process called...
a. dysbiosis
b. microbial antagonism
c. neutral interactions
d. microbial interactions
b. microbial antagonism
How do antimicrobial drugs that target folic acid synthesis provide selective toxicity?
a. humans do not have the enzymes to make this molecule
b. human versions of this structure are larger and have a different molecular structure
c. human cells do not have this cell structure
d. human cell structures do not have the molecule that this binds to
a. humans do not have the enzymes to make this molecule
Otic is the portal of exit that creates
a. discharge from ear infections contain
pathogenic organisms
b. eye infections that will cause tears to
harbor pathogenic organisms
c. Discharge from skin infections typically
contains both immune cells and pathogenic
organisms
d. harbored pathogens in urine and sexual
secretions
a. discharge from ear infections contain
pathogenic organisms
type 3 toxins...
a. break open holes in the membrane of host cells
b. destroys the membrane of red blood cells
c. use a cell receptor to enter the cell
d. bind to receptors on the cells of their hosts
c. use a cell receptor to enter the cell
An invasin is a virulence factor that _________________
a. allows microbes to break down and spread through tissues
b. allows microbes to acquire nutrients from the host
c. allows microbes to coat themselves in host antigens
d. allows microbes to stick to body surfaces
a. allows microbes to break down and spread through tissues
T or F
to cause an infection, all opportunistic pathogens require either dysbiosis or
a homeostatic imbalance in the host
True
How do antimicrobial drugs that target cell wall synthesis provide selective toxicity?
a. humans do not have the enzymes to make this molecule
b. human cells do not have this cell structure
c. human cell structures do not have the molecule that this binds to
d. human versions of this structure are larger and have a different molecular structure
b. human cells do not have this cell structure
select the best answer: mode of transmission is when-
a. when a pathogen is passed to a new
host
b. when a person is in contact with air containing airborne particles with pathogens
c. When a person comes in contact with organisms that are carriers of human pathogens between human hosts
d. Im not quite sure
a. when a pathogen is passed to a new
host
How does E. coli enterotoxin work?
a. it binds to T-cells and hyperactivates them which kills intestinal cells
b. it causes a powerful body-wide inflammatory reaction
c. it breaks open the membrane of red blood cells in the intestine
d. it binds to intestinal cells and causes them to leak salts and water
d. it binds to intestinal cells and causes them to leak salts and water
capsules, slime layers, and cell walls are coated in sugars similar to ones that human cells use, These sugars provide...
a. a layer of protection called biofilms
b. antigenic masking
c. antigenic variation
d. antigenic mimicry
d. antigenic mimicry
In order for opportunistic pathogens to cause infections, the host must _________________
a. be infected with an exotoxin-producing bacteria
b. carry that pathogen in their normal microbiota
c. experience some kind of homeostatic imbalance or dysbiosis
d. be exposed to a pathogen that can evade the immune system with antigenic variation
c. experience some kind of homeostatic imbalance or dysbiosis
Drugs called macrolides will block the part of
the ribosome where..
a. amino acids are formed
b. proteins are formed
c. peptide bonds are formed
d. hydrogen bonds are formed
c. peptide bonds are formed
which is not a form of direct contact
a. Animal contact
b. Vertical transmission
c. Vehicle transmission
d. Environmental contact
c. Vehicle transmission
Tetanus intoxication...
a. blocks the release of the neurotransmitter glycine
b. blocks the nerve cells that cause muscle contraction, called alpha motor neurons
c. punches holes into the host cell’s membrane
d. hyperactivates adaptive immune cells
a. blocks the release of the neurotransmitter glycine
In which type of immune system evasion does a microbial cell build its structures from molecules that are similar to antigens in the host?
a. antigenic masking
b. antigenic mimicry
c. phagocytic escape
d. antigenic variation
b. antigenic mimicry
Every epithelial tissue on our body supports the growth of non-pathogenic microbes, These microbes are collectively called...
a. primary microbes
b. beneficial Interactions
c. microbial antagonism
d. normal microbiota
d. normal microbiota
A bacterial infection in one of your patients is identified as positive for the "beta-lactamase" enzyme. Which type of antibiotics will be ineffective against this infection?
a. drugs that break open the microbial cell membrane
b. drugs that interfere with cell wall synthesis
c. drugs that block folic acid synthesis
d. drugs that interfere with DNA replication
b. drugs that interfere with cell wall synthesis
Vector transmission is
a. Contact with objects or materials contaminated with pathogens or bodily fluids
b. Contact with organisms that are carriers of human pathogens between human hosts
c. Contact with pathogens in water or soil
d. Contact with air containing airborne particles with pathogens
b. Contact with organisms that are carriers of human pathogens between human hosts
How do microbial proteins called superantigens work?
a. they distract immune cells inot attacking the protein rather than the microbe
b. they coat the surface of microbes making it difficult for the immune system to identify them
c. they directly bind to and destroy the cells of the body
d. they hyperactivate adaptive immune cells
d. they hyperactivate adaptive immune cells
In which type of immune system evasion does a microbial cell alter its antigens to prevent the host from recognizing them?
a. antigenic variation
b. antigenic mimicry
c. antigenic masking
d. phagocytic escape
a. antigenic variation