Chapter 14

How does the protozoan Trypanosoma evade detection by the immune system? A.) It can change the surface antigens frequently, preventing the immune system from tracking it. B.) It produces a capsule which is composed of polysaccharides similar to those found in the host. C.) It can resist oxidation inside macrophages. D.) It prevents phagosome-lysosome fusion.

A

Mutualism is a relationship A.) that sometimes provides benefits for both members such that one or both parties cannot live without the other. B.) where one member of the relationship benefits without hurting the other. C.) where only one member derives benefit from the other. D.) where one member of the relationship may kill the other. E.)where it is difficult to prove the benefits or disadvantages one member of the relationship may provide for the other.

A

Why may some bacteria use extracellular enzymes to form blood clots? A.) The blood clots are a necessary food source for the bacteria. B.) Blood clot can hide bacteria from the immune system. C.) The blood clots cause disease, which is the intended purpose of the bacteria. D.) A blood clot leads to tissue necrosis or death, a necessary condition for infection.

B

Which domain of the A-B toxin binds to cell surface receptors on the host cell? B domain A domain Both the A and B domains have the ability to bind to cell surface receptors. A-B toxins do not bind to cell surfaces.

B domain

A new drug blocks the adhesins on the surface of a bacterial pathogen. What would likely be the major effect of this drug? A.) It will inhibit the growth and reproduction of this pathogen. B.) It will kill the pathogen. C.) It will prevent infection by this pathogen. D.) It will prevent formation of the glycocalyx in this pathogen.

C

How do Shigella cells move between host cells? A.) They are secreted directly into the epithelial cells from the M cells. B.) They are secreted by phagocytes. C.) They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another. D.) They lyse the M cell, releasing thousands of new cells to infect other host cells.

C

How do fibrinolysins enhance a pathogen's virulence? A.) They destroy the molecules that hold cells together. B.) They destroy the fibers that are found at the base of superficial tissues, allowing for deeper penetration by the pathogen. C.) They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.

C

How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system? A.) They cause fever, which destroys the complement proteins. B.) They cause the immune system to destroy IgA antibodies. C.) They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen. D.) They cause the immune system to turn on itself.

C

How does a capsule help certain bacteria evade detection by the immune system? A.) The capsule makes the bacterium too sticky to be phagocytosed by the immune cells. B.) Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. C.) 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. D.)Capsules have the ability to destroy antibodies secreted by the immune system.

C

Microbes known as transient microbiota are A.) microorganisms that remain with the person throughout life. B.)unsuccessful microbial invaders because of the presence of preexisting microbes. C.) organisms that remain in the body for a short time. D.) microorganisms that may cause a disease under certain circumstances. E.)sources of microbial contamination.

C

Hyaluronidase and collagenase both allow bacteria to _____. escape detection by a host interfere with complement invade a host's tissues adhere to body cells

invade a host's tissues

Why is a release of endotoxin into the bloodstream potentially deadly? Endotoxin can quickly enter the brain from the bloodstream, causing brain damage. It causes necrosis of the liver. It results in dehydration of the patient. It can lower blood pressure and cause the patient to go into shock.

it can lower BP and cause the patient to go into shock

fever, blood clotting, inflammation, and shock are all effects of?

lipid A

tuberculosis bacterium actually grows inside the?

macrophage

What are leukocidins? Molecules that destroy the complement proteins Molecules that can degrade IgA Molecules that are capable of destroying phagocytes

molecules that are capable of destroying phagocytes

________ is a relationship that sometimes provides benefits for both members such that one or both parties cannot live without the other.

mutualism

A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n) superantigen. neurotoxin. membrane disrupting toxin. enterotoxin.

neurotoxin

organisms that colonize in the body's surfaces without normally causing disease

normal microbiota

what is also termed normal flora and indigenous microbiota

normal microbiota

A major difference between exotoxins and endotoxins is that endotoxins are _____. secreted by bacteria not actually toxic able to kill cells directly physically part of the bacterial structure

physically part of the bacterial structure

Bacterial capsules work by _____. protecting the bacterium from engulfment killing the phagocyte preventing the action of complement preventing synthesis of digestive chemicals by phagocytes

protecting the bacterium from engulfment

a source of microbial contamination

reservoir

Which of the following virulence factors would be found in Staphylococcus aureus? Hyaluronidase Collagenase Streptokinase Staphylokinase

staphlokinase

etiology

study of the cause of disease

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) enterotoxin. membrane disrupting toxin. cytotoxin. superantigen.

superantigen

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

superantigens

How are superantigens different from other types of exotoxins? Superantigens cause an overstimulation of the host immune system. Superantigens comprise 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

A strain of Neisseria gonorrhea has a mutation which has caused it to lose the ability to produce fimbriae and become less virulent as a consequence. What function has this pathogen lost? the ability to produce an endotoxin the ability to adhere to cells of the body the ability to prevent phagocytes killing it the ability to establish a latent infection the ability to move from one location in the body to another

the ability to adhere to cells of the body

virulence

the degree to which a microbe is able to cause disease

Epidemiology

the study of the distribution, occurance of a disease

How are immune cells able to detect foreign pathogens? They can compare the DNA sequences from the foreign cells to host DNA. They are able to detect structures on the surfaces of foreign cells that are not found in the host. They detect foreign, unfamiliar chemical substances released by the invading cells.

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

resident microbiota

-are a part of the normal microbiota throughout life -are mostly commensal

A pathogen is best described as A.) any microorganism that causes disease. B.) a source of microbial contamination. C.) a microorganism that remains with the person throughout life. D.) an organism that remains in the body for a short time. E.) a microorganism that may cause a disease under certain circumstances.

A

Fomites are A.) inanimate objects involved in the indirect contact transmission of pathogens. B.) animal sources for human pathogens. C.) silent carriers of infectious diseases. D.)insects that transmit pathogens from an infected host to a noninfected host. E.)fecal material from infected hosts.

A

endotoxin

A toxic component of the outer membrane of certain gram-negative bacteria that is released only when the bacteria die. LIPID A

The bacterium that causes tuberculosis can be expelled from the lungs by a cough and remain viable in the air for an hour or more. If a person inhales the bacteria from the air, what type of transmission has occurred? indirect contact bodily fluid foodborne waterborne airborne

airborne

bacteria in the lower digestive tract are strictly?

anaerobes or faculative anaerobes

The typical relationship between the resident microbiota and the transient microbiota is which of the following? mutualism parasitism commensalism antagonism

antagonism

Places in the body where there is no normal microbiota are referred to as (sterile/aseptic/axenic).

axenic

what protects bacteria from engulfment

bacterial capsules

Superantigens

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

normal microbiota are organisms that ____________ the body's surfaces without normally causing disease

colonize

Lipid A is a(n) (cytotoxin/endotoxin/exotoxin) that stimulates the body to release chemicals that cause fever, inflammation, diarrhea, hemorrhaging, shock, and blood coagulation.

endotoxin

lipid a is an

endotoxin

____toxins are physically part of the bacterial structure

endotoxins

Which type of toxin, when secreted, may lead to the disruption of the cells within the gastrointestinal tract? endotoxin cytotoxin enterotoxin neurotoxin

enterotoxin

________ are responsible for the disruption and possible destruction of host cells and tissues within the digestive tract.

enterotoxins

The study of the cause of disease is known as (epidemiology/etiology/pathology).

etiology

Which of the following would be the first sign of an infection that resulted in the release of endotoxin? Pain Nausea Fever Weakness

fever

FBIS

fever blood clotting inflammation shock ALL effects of lipid A

Among the virulence factors produced by Staphylococcus aureus are hemolysin, coagulase, hyaluronidase, and enterotoxin. Which of these factors contribute to the ability of S. aureus to invade the body? enterotoxin hyaluronidase coagulase coagulase and hemolysin hemolysin

hyaluronidase

Which of the following enzymes breaks down the "glue" that holds cells together? Hyaluronidase Streptokinase Fibrinolysin Collagenase

hyaluronidase

Where do Salmonella pathogens grow and replicate in the infected host? Inside intestinal epithelial cells Inside phagocytes Inside M cells Inside Shigella cells

inside phagocytes

molecules that are capable of destroying phagocytes

leukocidins

microorganisms that may cause a disease under certain circumstances.

opportunistic microorganisms

normal micriobiota in hosts

organisms that colonize the body's surfaces without normally causing disease

any microorganism that causes disease

pathogen

are part of normal microbiota throughout life

resident microbiota

microorganisms that remain with the person throughout life.

resident microbiota

What is the etiologic agent of typhoid? E. coli Shigella Salmonella

salmonella

Measles viruses are capable of inactivating host defenses by destroying complement proteins. producing superantigens. suppressing the immune system. producing leukocidins.

suppressing the immune system

virulence factors

traits of a microbe that promote pathogenicity

organisms that remain in the body for a shortime

transient microbiota

blood clots can hide bacteria from the immune system t or f

true

in the womb we do not have any microbiota t or f

true

Which of the following microorganisms actually grows inside the macrophage? Leishmania Legionella Streptococcus pneumoniae Tuberculosis bacterium Shigella

tuberculosis bacterium

salmonella is the etiological agent of?

typhoid

The degree to which a microbe is able to cause disease is known as its (morbidity/virulence/toxicity).

virulence

Certain traits that allow pathogens to create infection and cause disease are termed virulence factors. collagenases. hyaluronidases. streptokinases.

virulence factors

When would endotoxins be released from a bacterial cell? When the cell moves toward a energy source During bacterial conjugation When the cell attaches to a host cell in the human body When the cell dies

when the cell dies

what parts of the body are axenic

womb, alveoli of lungs, and deeper skin

lysosome

An organelle containing digestive enzymes

An epidemiologist collects drinking glasses, tissues, and bed sheets from the apartment of an individual infected with a particular disease. Which of the following modes of transmission is being investigated for this disease? direct contact transmission vehicle transmission indirect contact transmission vector transmission

indirect contact transmission

Endotoxins are also known as

Lipid A

example of endotoxin

Lipid A of LPS

Where is the site of Shigella attachment in the host? Phagocytes Intestinal epithelial cells M cells Leukocytes

M cells

Meningitis and gonorrhea are caused by Neisseria species. measles virus. Pseudomonas species.

Neisseria species

The release of lipid A may lead to _____. fever, blood clotting, muscle contraction, and anemia seizures, anemia, inflammation, and shock hypothermia, blood clotting, pus formation, and shock fever, blood clotting, inflammation, and shock

fever, blood clotting, inflammation, and shock

Much of one's resident microbiota established during

first months of life

cytotoxin

a substance toxic to cells

free of microbes

axenic

the womb, alveoli of lungs, and deeper skin are all?

axenic

The fungus Pneumocystis jiroveci is found in the lungs of most people in low numbers, but in immunocompromised people it overgrows, resulting in severe respiratory problems. The fungus is best described as resident microbiota. a parasite. a mutualist symbiotic partner. transient microbiota. both resident microbiota and opportunistic pathogen.

both resident microbiota and opportunistic pathogen

Virulence factors allow microbes to be pathogens. This means that a bacterium with more virulence factors _____. will be more deadly can more easily infect hosts and cause disease cause a more severe immune response by the host can infect a greater variety of hosts

can more easily infect hosts and cause disease

How can capsules enable bacteria to evade the immune system? Capsules block the complement biding sites on the surface of the pathogen. Capsules can bind up IgA, rendering it inactive. A capsule is a superantigen that distracts the immune system.

capsules block the complement biding sites in the surface of the pathogen

The close contact between newborns and family members allow them to become ________ with microbes that become established as their microbiota. (Choose the most accurate term.) infiltrated colonized infected parasitized contaminated

colonized

resident microbiota are mostly?

commensal

a relationship between two organisms where only one member benefits.

commensalism

An exotoxin that has the ability to kill or damage host cells is referred to as a(n) superantigen. enterotoxin. cytotoxin. neurotoxin. A-B toxin.

cytotoxin

Which of the following features of Salmonella prevent it from being phagocytosed? Flagella Fimbriae Invasins

flagella

inanimate objects involved in the indirect contact transmission of pathogens

fomite

axenic

free of microbes

axenic

free of microorganisms

Human normal microbiota begin to develop __________. during adulthood at puberty before birth during birth

during birth

When do microbiota begin to develop?

during the birthing process

Some bacteria secrete chemicals that prevent the phagocytic digestion of a bacterium by interfering with the fusion of _____ to the phagosome. a lysosome pseudopods the bacterium a lipopolysaccharide layer (LPS)

a lysosome

neurotoxin

a poison that acts on the nervous system.

Commensalism is best described as

a relationship between two organisms where only one member benefits.

A reservoir is any microorganism that causes disease. a condition in which organisms remain in the body for a short time. a source of microbes for laboratory testing. a source of microbial contamination. an environment that is free of microbes.

a source of microbial contamination