Question 1

Which type of toxin is pictured?

Accepted Answer

A)  endotoxin 
B)  type 1 exotoxin 
C)  type 2 exotoxin 
D)  type 3 exotoxin 
E)  either type 1, type 2, or type 3 exotoxins

Question 2

Which type of bacterial toxin is matched incorrectly with its description?

Accepted Answer

A)  type 3 exotoxin: bind to a membrane receptor then enter the cell 
B)  toxemia: a toxin produced during a viral infection 
C)  endotoxin: enters the bloodstream during infection with Gram- negative bacteria 
D)  type 1 exotoxin: bind to the targeted host cell at a membrane receptor but do not enter the cell 
E)  type 2 exotoxin: disrupt and damage the host cell membrane leading to cell lysis

Question 3

Which of the following can be a potential disease reservoir for a pathogen which infects humans?

Accepted Answer

A)  only humans or inanimate objects that an infected human directly handles 
B)  Humans, non- human animals, inanimate objects, or environmental niches can all serve as reservoirs for a pathogen which infects humans. 
C)  environmental niches such as soil or water 
D)  only humans 
E)  only humans or non- human animals

Question 4

Droplet and airborne precautions

Accepted Answer

A)  both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route. 
B)  both involve transmission through fine aerosols which require close contact for transmission. 
C)  both require isolation in a specially- ventilated room (AIIR). 
D)  both require the use of a procedural mask. 
E)  both require use of an N95 respirator.

Question 5

A pathogen which uses a specific portal of entry will only be able to establish an infection in the system associated with that portal.

Accepted Answer

A) True 
 B)False

Question 6

A newly emerged infectious disease whose pathogen cause has not yet been identified is lethal in more than 90% of cases. Epidemiological evidence suggests that this pathogen is transmitted only through direct contact with the blood of ill or recently deceased patients. Patient blood and tissue samples would best be handled at BSL- 2 until more information can be learned about the pathogen.

Accepted Answer

A) True 
 B)False

Question 7

Exotoxins are

Accepted Answer

A)  secreted. 
B)  the targets of some childhood vaccines. 
C)  only made by Gram- positive bacteria. 
D)  secreted and only made by Gram- positive bacteria. 
E)  secreted and the targets of some childhood vaccines.

Question 8

The role of healthcare workers in the management of disease outbreaks

Accepted Answer

A)  should be addressed through periodic training and re- training. 
B)  is limited to properly using personal protective equipment. 
C)  is only important in BSL- 3 or higher facilities. 
D)  can be approached casually. 
E)  is not critical in U.S. healthcare facilities.

Question 9

A microbe is either pathogenic or it is not. A microbe is either virulent or it is not. Both pathogenicity and virulence are all- or- nothing terms.

Accepted Answer

A) True 
 B)False

Question 10

Host- microbe interactions

Accepted Answer

A)  are generally commensal. 
B)  are always harmful. 
C)  involve a dynamic give- and- take between the microbe and the host. 
D)  do not involve host factors. 
E)  never result in the normal species of the microbiota causing disease.

Question 11

Which is not a category of virulence factors?

Accepted Answer

A)  immune system evasion 
B)  adhesion 
C)  toxins 
D)  attenuation 
E)  nutrient acquisition

Question 12

If you had the ability to genetically engineer a pathogenic bacterium, what features would you include? Choose a portal of entry and a portal of exit for your pathogen. Then choose three virulence factors from at least two the following areas: toxins, adhesins, invasins, acquisition of nutrients, and avoidance of the immune system, and describe how each factor will help your bacterium survive in the host. Your virulence factors should make sense for the portals of entry and exit that you chose.

Accepted Answer

The answer of If you had the ability to genetically...

Question 13

The preference of a pathogen for a specific host is

Accepted Answer

A)  opportunism. 
B)  tropism. 
C)  virulence. 
D)  dysbiosis. 
E)  pathogenicity.

Question 14

Which mode of transmission is not addressed by transmission precautions?

Accepted Answer

A)  airborne and droplet 
B)  airborne 
C)  direct contact 
D)  droplet 
E)  vector

Question 15

Which of the following microbes are classified as BSL- 2?

Accepted Answer

A)  Both Staphylococcus aureus and Staphylococcus epidermidis 
B)  Staphylococcus epidermidis 
C)  E. coli K- 12 
D)  Bacillus subtilis 
E)  Staphylococcus aureus

Question 16

Adhesins

Accepted Answer

A)  include molecules that are typically found deep inside the pathogenic cell. 
B)  make poor targets for vaccine development. 
C)  include molecules that bind to host factors such as fibronectin, sialic acid, and heparin / heparin sulfate. 
D)  allow pathogens to stick to host tissues only in a nonspecific manner. 
E)  are limited to only a few known types.

Question 17

More than half of new infectious diseases in humans emerged due to expanded host tropism by the infectious organism.

Accepted Answer

A) True 
 B)False

Question 18

Which portal of entry is mismatched to its description?

Accepted Answer

A)  parenteral: pathogen is passed from mother to child through the placenta 
B)  ocular: via the conjunctiva 
C)  otic: pathogen enters via the ear 
D)  urogenital: often associated with sexually- transmitted pathogens 
E)  gastrointestinal: often involves fecal- to- oral transmission

Question 19

Which statement is true about standard precautions?

Accepted Answer

A)  They are used in student labs that only handle BSL- 1 pathogens 
B)  They are in force only for bloodborne pathogens. 
C)  They apply to all healthcare providers working with all patients. 
D)  They require full face shields, gloves, and barrier gowns for all patient contact situations. 
E)  They are used only when the patient is known to be infected with a BSL- 2 or higher pathogen.

Question 20

Pathogens can obtain iron from the body using

Accepted Answer

A)  transferrin. 
B)  lipases. 
C)  proteases. 
D)  siderophores or transferrin. 
E)  siderophores.

Exam 10: Host-Microbe Interactions and Pathogenesis

Which type of toxin is pictured?

Which type of bacterial toxin is matched incorrectly with its description?

Which of the following can be a potential disease reservoir for a pathogen which infects humans?

Droplet and airborne precautions

A pathogen which uses a specific portal of entry will only be able to establish an infection in the system associated with that portal.

Exotoxins are

The role of healthcare workers in the management of disease outbreaks

A microbe is either pathogenic or it is not. A microbe is either virulent or it is not. Both pathogenicity and virulence are all- or- nothing terms.

Host- microbe interactions

Which is not a category of virulence factors?

The preference of a pathogen for a specific host is

Which mode of transmission is not addressed by transmission precautions?

Which of the following microbes are classified as BSL- 2?

Adhesins

More than half of new infectious diseases in humans emerged due to expanded host tropism by the infectious organism.

Which portal of entry is mismatched to its description?

Which statement is true about standard precautions?

Pathogens can obtain iron from the body using