Multiple Choice

Which of the following would be a sign of an infection?

1. muscle aches
2. headache
3. fever
4. nausea

Which of the following is an example of a noncommunicable infectious disease?

1. infection with a respiratory virus
2. food poisoning due to a preformed bacterial toxin in food
3. skin infection acquired from a dog bite
4. infection acquired from the stick of a contaminated needle

During an oral surgery, the surgeon nicked the patient’s gum with a sharp instrument. This allowed Streptococcus, a bacterium normally present in the mouth, to gain access to the blood. As a result, the patient developed bacterial endocarditis (an infection of the heart). Which type of disease is this?

1. iatrogenic
2. nosocomial
3. vectors
4. zoonotic

Which period is the stage of disease during which the patient begins to present general signs and symptoms?

1. convalescence
2. incubation
3. illness
4. prodromal

A communicable disease that can be easily transmitted from person to person is which type of disease?

1. contagious
2. iatrogenic
3. acute
4. nosocomial

Which of the following is a pathogen that could not be identified by the original Koch’s postulates?

1. Staphylococcus aureus
2. Pseudomonas aeruginosa
3. Human immunodeficiency virus
4. Salmonella enterica serovar Typhimurium

Pathogen A has an ID₅₀ of 50 particles, pathogen B has an ID₅₀ of 1,000 particles, and pathogen C has an ID₅₀ of 1 × 10⁶ particles. Which pathogen is most virulent?

1. pathogen A
2. pathogen B
3. pathogen C

Which of the following choices lists the steps of pathogenesis in the correct order?

1. invasion, infection, adhesion, exposure
2. adhesion, exposure, infection, invasion
3. exposure, adhesion, invasion, infection
4. disease, infection, exposure, invasion

Which of the following would be a virulence factor of a pathogen?

1. a surface protein allowing the pathogen to bind to host cells
2. a secondary host the pathogen can infect
3. a surface protein the host immune system recognizes
4. the ability to form a provirus

You have recently identified a new toxin. It is produced by a gram-negative bacterium. It is composed mostly of protein, has high toxicity, and is not heat stable. You also discover that it targets liver cells. Based on these characteristics, how would you classify this toxin?

1. superantigen
2. endotoxin
3. exotoxin
4. leukocidin

Which of the following applies to hyaluronidase?

1. It acts as a spreading factor.
2. It promotes blood clotting.
3. It is an example of an adhesin.
4. It is produced by immune cells to target pathogens.

Phospholipases are enzymes that do which of the following?

1. degrade antibodies
2. promote pathogen spread through connective tissue.
3. degrade nucleic acid to promote spread of pathogen
4. degrade cell membranes to allow pathogens to escape phagosomes

Which of the following is a major virulence factor for the fungal pathogen Cryptococcus?

1. hemolysin
2. capsule
3. collagenase
4. fimbriae

Which of the following pathogens undergoes antigenic variation to avoid immune defenses?

1. Candida
2. Cryptococcus
3. Plasmodium
4. Giardia