Deck 21: Respiratory System Infections

Question 1

A physician is advising the family on the condition of a diphtheria patient. How would the physician explain why the disease affects some tissues and not others?

Answer 1

The bacteria belongs to the Genus Corynebacterium (gram positive) contains high G+C (guanine + cytosine) content in their genome. C. diphtheriae causes diphtheria in humans.
C. diphtheriae releases an A-B exotoxin. The gene coding for diphtheria toxin is located in a bacteriophage.
The B component of the toxin attach to the surface receptor and enter into the endocytic vacuole. After entering into the cell, the toxin (chain A) toxin act by inhibiting the protein synthesis, and damage the throat region locally. The toxin do not cause systemic effects because it only kills the cells that it can attach to and enter. In some cases, the toxin can also attach to the cells of heart, kidneys, and neurons.

Question 2

If all transmission of Mycobacterium tuberculosis from one person to another were stopped, how long would it take for the world to be rid of the disease?

Answer 2

The mycobacteria can survive within the macrophages after phagocytosis. It triggers a delayed-type hypersensitivity reaction and forms hard tubercles at the site of infection, which then develop into cutaneous lesions.
These lesions calcify into "Ghon complexes." The organisms trapped in this manner are either killed by the immune system or carried by the immune system for prolonged periods. This stage of infection is called "latent tuberculosis infection (LTBI)," but it is not infectious.
As the Mycobacterium can stay dormant in the macrophages of the infected person for a lifetime (LTBI), it is considered that TB cannot be eradicated completely if all the infected people die or until the last infected person dies.

Question 3

The respiratory system provides a warm, moist environment for microorganisms. It is protected by tonsils and adenoids, and by the mucociliary escalator. The upper respiratory tract contains highly diverse microbiota. Some members of the normal microbiota are opportunistic pathogens. The lower respiratory system is free of a normal microbiota.
What is the normal function of the tonsils and adenoids?

Answer 3

Tonsils are lumps of lymphoid tissues (similar to lymph nodes) found on both sides of the top of the pharynx. The adenoids (or pharyngeal tonsil) are a single mass of lymphoid tissue situated in the roof of the nasopharynx, where the nasal cavity blends into the throat.
Tonsils and adenoids are strategically located at the entrance to the breathing passages where they trap incoming pathogens or infectious agents. Their main function seems to be to produce antibodies and trigger the body's immune system to resist and fight future infections. Tonsils and adenoids function only for the first few years of life and wither away as we grow older.

Question 4

The following are all complications of streptococcal pharyngitis except

A) glomerulonephritis.
B) scarlet fever.
C) subacute bacterial endocarditis.
D) acute rheumatic fever.
E) Reye's syndrome.

Question 5

How does contamination of the eye lead to upper respiratory infection?

Question 6

How should a physician respond to a mother who asks if her daughter can get pneumococcal pneumonia again?

Question 7

Medications that prevent and treat influenza by binding to neuraminidase on the viral surface act against all the kinds of influenza viruses that infect humans. What does this imply about the nature of the interaction between the medications and the neuraminidase molecules?

Question 8

The respiratory system provides a warm, moist environment for microorganisms. It is protected by tonsils and adenoids, and by the mucociliary escalator. The upper respiratory tract contains highly diverse microbiota. Some members of the normal microbiota are opportunistic pathogens. The lower respiratory system is free of a normal microbiota.
Describe the normal microbiota of the respiratory system.

Question 9

All of the following are true of diphtheria except

A) a membrane that forms in the throat can cause suffocation.
B) a toxin is produced that interferes with ribosome function.
C) the causative organism typically invades the bloodstream.
D) immunization with a toxoid prevents the disease.
E) nerve injury with paralysis is common.

Question 10

After you recover from strep throat, can you get it again? Explain.

Question 11

The respiratory system provides a warm, moist environment for microorganisms. It is protected by tonsils and adenoids, and by the mucociliary escalator. The upper respiratory tract contains highly diverse microbiota. Some members of the normal microbiota are opportunistic pathogens. The lower respiratory system is free of a normal microbiota.
How would paralysis of the cilia affect the respiratory system?

Question 12

Adenoviral infections and the common cold are both

A) caused by picornaviruses.
B) often associated with fever.
C) associated with severe sore throat.
D) lower respiratory infections.
E) avoided by handwashing.

Question 13

Where is the gene for diphtheria toxin production located?

Question 14

Streptococcus pyogenes, a group A streptococcus with many virulence factors, causes a sore throat commonly known as strep throat. Untreated S. pyogenes infections can sometimes cause serious diseases (sequelae) in other parts of the body long after the initial infections have resolved. In diphtheria, toxin is absorbed into the bloodstream and circulates throughout the body, selectively damaging certain tissues such as heart, kidneys, and nerves. Conjunctivitis, otitis media, and sinusitis are common infections that often occur together and are caused by the same pathogens.
Name two post-streptococcal sequelae.

Question 15

All are true of mycoplasmal pneumonia except

A) it is a mycosis.
B) it usually does not require hospitalization.
C) penicillin is ineffective for treatment.
D) it is the leading cause of bacterial pneumonia in college students.
E) the infectious dose of the causative organism is low.

Question 16

Describe two ways to decrease the chance of contracting a cold.

Question 17

Streptococcus pyogenes, a group A streptococcus with many virulence factors, causes a sore throat commonly known as strep throat. Untreated S. pyogenes infections can sometimes cause serious diseases (sequelae) in other parts of the body long after the initial infections have resolved. In diphtheria, toxin is absorbed into the bloodstream and circulates throughout the body, selectively damaging certain tissues such as heart, kidneys, and nerves. Conjunctivitis, otitis media, and sinusitis are common infections that often occur together and are caused by the same pathogens.
How does diphtheria toxin kill cells?

Question 18

All of the following are true of Legionnaires' disease except

A) the causative organism can grow inside protozoa.
B) it spreads readily from person to person.
C) it is more likely to occur in long-term cigarette smokers than in nonsmokers.
D) it is often associated with diarrhea or other intestinal symptoms.
E) it can be contracted from household water supplies.

Question 19

What kinds of diseases are caused by adenoviruses?

Question 20

Streptococcus pyogenes, a group A streptococcus with many virulence factors, causes a sore throat commonly known as strep throat. Untreated S. pyogenes infections can sometimes cause serious diseases (sequelae) in other parts of the body long after the initial infections have resolved. In diphtheria, toxin is absorbed into the bloodstream and circulates throughout the body, selectively damaging certain tissues such as heart, kidneys, and nerves. Conjunctivitis, otitis media, and sinusitis are common infections that often occur together and are caused by the same pathogens.
How would adequate ventilation help to prevent the spread of streptococcal infections?

Question 21

Which of the following infectious agents is most likely to cause a pandemic?

A) Influenza A virus
B) Streptococcus pyogenes
C) Histoplasma capsulatum
D) Sin Nombre virus
E) Coccidioides immitis

Question 22

How do alcoholism and cigarette smoking predispose a person to pneumonia?

Question 23

Many different kinds of infectious agents cause upper respiratory tract diseases, often with the same signs and symptoms. Emotional stress significantly increases the risk of contracting the common cold, but exposure to cold temperatures probably does not. People with a cold are most likely to transmit it if symptoms are severe, and during the first few days of illness. Adenovirus infections resemble colds, but fever is present.
Why are there no vaccines for the common cold?

Question 24

Respiratory syncytial virus

A) is a leading cause of serious lower respiratory tract infections in infants.
B) is an enveloped DNA virus of the adenovirus family.
C) attaches to host cell membranes by means of neuraminidase.
D) poses no threat to elderly people.
E) mainly causes disease in the summer months.

Question 25

Give a mechanism by which Klebsiella sp. Become antibiotic-resistant.

Question 26

Many different kinds of infectious agents cause upper respiratory tract diseases, often with the same signs and symptoms. Emotional stress significantly increases the risk of contracting the common cold, but exposure to cold temperatures probably does not. People with a cold are most likely to transmit it if symptoms are severe, and during the first few days of illness. Adenovirus infections resemble colds, but fever is present.
How is an adenovirus infection treated?

Question 27

In the United States, hantaviruses

A) are limited to southwestern states.
B) are carried only by deer mice.
C) infect human beings with a fatality rate of about 30%.
D) were first identified in the early 1970s.
E) are contracted mainly in bat caves.

Question 28

Why does the incidence of whooping cough rise promptly when pertussis immunizations are stopped?

Question 29

Many different kinds of infectious agents cause upper respiratory tract diseases, often with the same signs and symptoms. Emotional stress significantly increases the risk of contracting the common cold, but exposure to cold temperatures probably does not. People with a cold are most likely to transmit it if symptoms are severe, and during the first few days of illness. Adenovirus infections resemble colds, but fever is present.
People who work at polar ice stations often do not develop colds. Is this an expected observation? Why or why not?

Question 30

All of the following are true of coccidioidomycosis except

A) it is contracted by inhaling arthrospores.
B) it is caused by a dimorphic fungus.
C) endospores are produced within a spherule.
D) it is more common in Maryland than in California.
E) it is often associated with painful nodules on the legs.

Question 31

Why are two or more antitubercular medications used together to treat TB disease?

Question 32

Pneumococcal pneumonia is typically community-acquired in adults. Pneumonia due to Klebsiella sp. is mainly hospitalacquired and leads the causes of death from healthcare-associated infections. Mycoplasmal pneumonia usually does not require hospitalization. Whooping cough (pertussis) is mainly a threat to infants but is commonly spread by adults; childhood immunization against the disease protects them, but immunity often does not persist to adulthood. Tuberculosis is a chronic disease spread from one person to another by aerosol drops. Most Mycobacterium tuberculosis infections become latent, posing the risk of reactivation throughout life. Legionella pneumophila, the bacterium that causes Legionnaires' disease, originates from water containing other microorganisms, where it can grow within protozoa.
What structural feature of the S. pneumoniae cell is responsible for its virulence?

Question 33

The disease histoplasmosis

A) is caused by an encapsulated bacterium.
B) is contracted by inhaling arthrospores.
C) occurs mostly in hot, dry, and dusty areas of the American Southwest.
D) is a threat to AIDS patients living in areas bordering the Mississippi River.
E) is commonly fatal for pigeons and bats.

Question 34

Why did it take so long to discover the cause of Legionnaires' disease?

Question 35

Pneumococcal pneumonia is typically community-acquired in adults. Pneumonia due to Klebsiella sp. is mainly hospitalacquired and leads the causes of death from healthcare-associated infections. Mycoplasmal pneumonia usually does not require hospitalization. Whooping cough (pertussis) is mainly a threat to infants but is commonly spread by adults; childhood immunization against the disease protects them, but immunity often does not persist to adulthood. Tuberculosis is a chronic disease spread from one person to another by aerosol drops. Most Mycobacterium tuberculosis infections become latent, posing the risk of reactivation throughout life. Legionella pneumophila, the bacterium that causes Legionnaires' disease, originates from water containing other microorganisms, where it can grow within protozoa.
Outline the pathogenesis of tuberculosis.

Question 36

Pneumococcal pneumonia is typically community-acquired in adults. Pneumonia due to Klebsiella sp. is mainly hospitalacquired and leads the causes of death from healthcare-associated infections. Mycoplasmal pneumonia usually does not require hospitalization. Whooping cough (pertussis) is mainly a threat to infants but is commonly spread by adults; childhood immunization against the disease protects them, but immunity often does not persist to adulthood. Tuberculosis is a chronic disease spread from one person to another by aerosol drops. Most Mycobacterium tuberculosis infections become latent, posing the risk of reactivation throughout life. Legionella pneumophila, the bacterium that causes Legionnaires' disease, originates from water containing other microorganisms, where it can grow within protozoa.
Why is pertussis toxin not eliminated by the mucociliary escalator?

Question 37

The speed with which influenza travels around the world and the rapid evolution of the virus due to antigenic drift and shift make the disease an extremely serious threat to humankind. Most deaths from influenza are caused by secondary bacterial infections. Respiratory syncytial virus is the leading cause of serious respiratory disease in infants and young children. Hantavirus pulmonary syndrome is often fatal. It is contracted from inhalation of dust contaminated by urine, feces, or saliva from mice infected with certain hantaviruses.
Why are there so many deaths from influenza when it is generally a mild disease?

Question 38

The speed with which influenza travels around the world and the rapid evolution of the virus due to antigenic drift and shift make the disease an extremely serious threat to humankind. Most deaths from influenza are caused by secondary bacterial infections. Respiratory syncytial virus is the leading cause of serious respiratory disease in infants and young children. Hantavirus pulmonary syndrome is often fatal. It is contracted from inhalation of dust contaminated by urine, feces, or saliva from mice infected with certain hantaviruses.
What is the source of the virus that causes hantavirus pulmonary syndrome?

Question 39

The speed with which influenza travels around the world and the rapid evolution of the virus due to antigenic drift and shift make the disease an extremely serious threat to humankind. Most deaths from influenza are caused by secondary bacterial infections. Respiratory syncytial virus is the leading cause of serious respiratory disease in infants and young children. Hantavirus pulmonary syndrome is often fatal. It is contracted from inhalation of dust contaminated by urine, feces, or saliva from mice infected with certain hantaviruses.
Why might you expect an influenza epidemic to be more severe following an antigenic shift in the virus rather than after antigenic drift?

Question 40

Coccidioidomycosis and histoplasmosis are two diseases caused by fungi that live in the soil. The body responds to these infections in a way that mimics tuberculosis. Pneumocystis pneumonia (PCP) affects immunocompromised people.
Why should an immunodeficient person avoid traveling through hot, dry, dusty areas of the Southwest?

Question 41

Coccidioidomycosis and histoplasmosis are two diseases caused by fungi that live in the soil. The body responds to these infections in a way that mimics tuberculosis. Pneumocystis pneumonia (PCP) affects immunocompromised people.
Why might cave exploration increase the risk of histoplasmosis?

Question 42

Coccidioidomycosis and histoplasmosis are two diseases caused by fungi that live in the soil. The body responds to these infections in a way that mimics tuberculosis. Pneumocystis pneumonia (PCP) affects immunocompromised people.
Several students staying in a hotel next to a bulldozing operation developed histoplasmosis. How might the bulldozing explain the outbreak?