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Chapter 15: Microbial Mechanisms of Pathogenicity

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Chapter 15: Microbial Mechanisms of Pathogenicity

26 problems · 0 figures

15-1 §15.MC source ↗

Which of the following would be a sign of an infection?
  1. a.
    muscle aches
  2. b.
    headache
  3. c.
    fever
  4. d.
    nausea

Answer

C. fever

15-2 §15.MC source ↗

Which of the following is an example of a noncommunicable infectious disease?
  1. a.
    infection with a respiratory virus
  2. b.
    food poisoning due to a preformed bacterial toxin in food
  3. c.
    skin infection acquired from a dog bite
  4. d.
    infection acquired from the stick of a contaminated needle

Answer

B. food poisoning due to a preformed bacterial toxin in food

15-3 §15.MC source ↗

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. a.
    iatrogenic
  2. b.
    nosocomial
  3. c.
    vectors
  4. d.
    zoonotic

Answer

A. iatrogenic

15-4 §15.MC source ↗

Which period is the stage of disease during which the patient begins to present general signs and symptoms?
  1. a.
    convalescence
  2. b.
    incubation
  3. c.
    illness
  4. d.
    prodromal

Answer

D. prodromal

15-5 §15.MC source ↗

A communicable disease that can be easily transmitted from person to person is which type of disease?
  1. a.
    contagious
  2. b.
    iatrogenic
  3. c.
    acute
  4. d.
    nosocomial

Answer

A. contagious

15-6 §15.MC source ↗

Which of the following is a pathogen that could not be identified by the original Koch’s postulates?
  1. a.
    Staphylococcus aureus
  2. b.
    Pseudomonas aeruginosa
  3. c.
    Human immunodeficiency virus
  4. d.
    Salmonella enterica serovar Typhimurium

Answer

C. Human immunodeficiency virus

15-7 §15.MC source ↗

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. a.
    pathogen A
  2. b.
    pathogen B
  3. c.
    pathogen C

Answer

A. pathogen A

15-8 §15.MC source ↗

Which of the following choices lists the steps of pathogenesis in the correct order?
  1. a.
    invasion, infection, adhesion, exposure
  2. b.
    adhesion, exposure, infection, invasion
  3. c.
    exposure, adhesion, invasion, infection
  4. d.
    disease, infection, exposure, invasion

Answer

C. exposure, adhesion, invasion, infection

15-9 §15.MC source ↗

Which of the following would be a virulence factor of a pathogen?
  1. a.
    a surface protein allowing the pathogen to bind to host cells
  2. b.
    a secondary host the pathogen can infect
  3. c.
    a surface protein the host immune system recognizes
  4. d.
    the ability to form a provirus

Answer

A. a surface protein allowing the pathogen to bind to host cells

15-10 §15.MC source ↗

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. a.
    superantigen
  2. b.
    endotoxin
  3. c.
    exotoxin
  4. d.
    leukocidin

Answer

C. exotoxin

15-11 §15.MC source ↗

Which of the following applies to hyaluronidase?
  1. a.
    It acts as a spreading factor.
  2. b.
    It promotes blood clotting.
  3. c.
    It is an example of an adhesin.
  4. d.
    It is produced by immune cells to target pathogens.

Answer

A. It acts as a spreading factor.

15-12 §15.MC source ↗

Phospholipases are enzymes that do which of the following?
  1. a.
    degrade antibodies
  2. b.
    promote pathogen spread through connective tissue.
  3. c.
    degrade nucleic acid to promote spread of pathogen
  4. d.
    degrade cell membranes to allow pathogens to escape phagosomes

Answer

D. degrade cell membranes to allow pathogens to escape phagosomes

15-13 §15.MC source ↗

Which of the following is a major virulence factor for the fungal pathogen Cryptococcus?
  1. a.
    hemolysin
  2. b.
    capsule
  3. c.
    collagenase
  4. d.
    fimbriae

Answer

B. capsule

15-14 §15.MC source ↗

Which of the following pathogens undergoes antigenic variation to avoid immune defenses?
  1. a.
    Candida
  2. b.
    Cryptococcus
  3. c.
    Plasmodium
  4. d.
    Giardia

Answer

C. Plasmodium

15-15 §15.FITB source ↗

A difference between an acute disease and chronic disease is that chronic diseases have an extended period of __________.

Answer

illness

15-16 §15.FITB source ↗

A person steps on a rusty nail and develops tetanus. In this case, the person has acquired a(n) __________ disease.

Answer

noncommunicable

15-17 §15.FITB source ↗

A(n) __________ pathogen causes disease only when conditions are favorable for the microorganism because of transfer to an inappropriate body site or weakened immunity in an individual.

Answer

opportunistic

15-18 §15.FITB source ↗

The concentration of pathogen needed to kill 50% of an infected group of test animals is the __________.

Answer

LD50

15-19 §15.FITB source ↗

A(n) __________ infection is a small region of infection from which a pathogen may move to another part of the body to establish a second infection.

Answer

focal

15-20 §15.FITB source ↗

Cilia, fimbriae, and pili are all examples of structures used by microbes for __________.

Answer

adhesion

15-21 §15.FITB source ↗

The glycoprotein adhesion gp120 on HIV must interact with __________ on some immune cells as the first step in the process of infecting the cell.

Answer

CD4

15-22 §15.FITB source ↗

Adhesins are usually located on __________ of the pathogen and are composed mainly of __________ and __________.

Answer

surface; proteins; sugars

15-23 §15.FITB source ↗

The Shiga and diphtheria toxins target __________ in host cells.

Answer

protein synthesis

15-24 §15.FITB source ↗

Antigenic __________ is the result of reassortment of genes responsible for the production of influenza virus spike proteins between different virus particles while in the same host, whereas antigenic __________ is the result of point mutations in the spike proteins.

Answer

shift; drift

15-25 §15.FITB source ↗

Candida can invade tissue by producing the exoenzymes __________ and __________.

Answer

protease and phospholipase

15-26 §15.FITB source ↗

The larval form of Schistosoma mansoni uses a __________ to help it gain entry through intact skin.

Answer

protease

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Problems and answers are adapted from Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister and Brian M. Forster, OpenStax, and are used under the CC BY-NC-SA 4.0 licence. Access for free at https://openstax.org/books/microbiology/pages/1-introduction. Illustrations: Copyright Rice University, OpenStax, under CC BY-NC-SA 4.0 license. This adaptation is released under the same licence, is non-commercial, and is neither affiliated with nor endorsed by OpenStax or Rice University.