21. Principles of Disease

Which of the following is not a method bacterial pathogens use to invade host cells in pathogenesis?

Compare and contrast mycoplasmas and viruses.

Discuss the prospects for the eradication of leptospirosis.

List the symptoms associated with the various stages of Schistosomiasis.

What three main options can a pathogen pursue following adhesion?

Amphotericin B is considered the “gold standard” of antifungal agents. Technically, its mode of action works against most fungal infections. Why, then, isn’t it prescribed for most fungal infections?

An animal that carries a pathogen and also serves as host for the pathogen is a ___________ vector.

The ID₅₀ for Campylobacter sp. is 500 cells; the ID₅₀ for Cryptosporidium sp. is 100 cells. Which of the following statements is false?

a. Both microbes are pathogens.

b. Both microbes produce infections in 50% of the inoculated hosts.

c. Campylobacter is more virulent than Cryptosporidium.

d. Campylobacter and Cryptosporidium are equally virulent; they cause infections in the same number of test animals.

e. Cryptosporidium infections are acquired more easily than Campylobacter infections.

Which best describes conjunctivitis (select ALL that apply)?

a. Itchy eyes

b. Scarred cornea

c. Red eyes

d. Inverted eyelashes

e. Scarred conjunctiva

Nonliving reservoirs of disease, such as a toothbrush, drinking glass, and needle, are called __________ .

Multifocal tuberculosis is characterized by:

A father suspects his son has intestinal worms due to his complaint of an itchy bottom. What habit is most likely responsible for his infection?

a. Walking outside barefoot

b. Eating without first washing hands

c. Eating fruit that is not washed

d. Eating undercooked meat

e. Swimming in a nearby freshwater lake

How would an upper endoscopy help diagnose a Helicobacter pylori infection?

The presence of lipid A in the outer membranes of Gram-negative bacteria.

a. Affects the formation of blood clots in the host

b. Causes these bacteria to be oxidase positive

c. Triggers the secretion of a protease enzyme to cleave IgA in mucus

d. Enables enteric bacteria to ferment glucose anaerobically