Question 1

A neutralizing antibody against a toxin is called a(n) __________.

Accepted Answer

The answer of A neutralizing antibody against a toxin is...

Question 2

Cholera toxin is an AB toxin.

Accepted Answer

Cholera toxin consists of two subunits known as A and B. The B subunit binds to specific receptors on the surface of intestinal cells, allowing the A subunit to enter the cell and exert its toxic effects. This makes it a classic example of an AB toxin.

Question 3

The toxic component of lipopolysaccharide is called

Accepted Answer

The toxic component of lipopolysaccharide, which is found in the outer membrane of Gram-negative bacteria, is called lipid A. It is responsible for initiating the inflammatory response in the host and can lead to septic shock if released into the bloodstream.

Question 4

Gas gangrene caused by Clostridium perfringens results from disruption of cell membranes caused by production of ____________.

Accepted Answer

The answer of Gas gangrene caused by Clostridium perfringens results...

Question 5

Generally, exotoxins tend to be more heat stable than endotoxins.

Accepted Answer

Endotoxins, which are part of the outer membrane of the cell wall of Gram-negative bacteria, tend to be more heat stable than exotoxins, which are usually proteins secreted by bacteria and can be denatured by heat.

Question 6

Virulence may be measured experimentally at the host level by the __________ __________ __________, which measures the number of pathogens that kills 50% of an experimental group of hosts within a specified amount of time.

Accepted Answer

The answer of Virulence may be measured experimentally at the...

Question 7

Many types of bacteria are only _________ when dispersing from more stable and heterogeneous communities known as biofilms.

Accepted Answer

The answer of Many types of bacteria are only _________...

Question 8

Many bacteria are pathogenic because they carry large segments of DNA called __________ _________, which were acquired by horizontal gene transfer, and which carry genes responsible for virulence.

Accepted Answer

The answer of Many bacteria are pathogenic because they carry...

Question 9

The only organisms to produce endotoxins are gram-negative bacteria.

Accepted Answer

Endotoxins are a type of bacterial toxin that is only produced by gram-negative bacteria, such as Escherichia coli and Salmonella. Gram-positive bacteria do not produce endotoxins.

Question 10

Macrophages are phagocytic cells.

Accepted Answer

Macrophages are a type of white blood cell that specialize in phagocytosis, which means they can engulf and destroy various types of particles, such as bacteria and dead cells.

Question 11

While exotoxin production is most generally associated with gram-positive bacteria, some Gram-negative bacteria also produce exotoxins.

Accepted Answer

Some examples of Gram-negative bacteria that produce exotoxins include Vibrio cholerae, Escherichia coli, and Bordetella pertussis. However, Gram-negative bacteria also have an outer membrane that can make it more difficult for exotoxins to enter host cells compared to Gram-positive bacteria.

Question 12

Colonization specifically refers to the multiplication of a pathogen on or within a host, and includes the resulting tissue invasion and damage.

Accepted Answer

Colonization refers to the multiplication of a pathogen on or within a host without causing tissue invasion or damage.

Question 13

The term __________ refers to the degree or intensity of pathogenicity.

Accepted Answer

The answer of The term __________ refers to the degree...

Question 14

Because LPS is bound to the surface of bacteria, it is called a(n) __________.

Accepted Answer

The answer of Because LPS is bound to the surface...

Question 15

The capacity of an organism to produce a toxin is called __________.

Accepted Answer

The answer of The capacity of an organism to produce...

Question 16

Fever response can be triggered by an endogenous pyrogen called interleukin-1.

Accepted Answer

Interleukin-1 is an endogenous pyrogen that can trigger fever response by acting on the hypothalamus to increase body temperature.

Question 17

Once a pathogen has infected the host, __________________ is a measure of the pathogen's ability to spread to adjacent or other tissues.

Accepted Answer

The answer of Once a pathogen has infected the host,...

Question 18

In the case of the AB toxins, the function of the B subunit is to

Accepted Answer

The function of the B subunit in AB toxins is to bind to the host cell receptor, allowing the toxin to enter the cell and perform its toxic function. The A subunit is responsible for the toxic activity of the toxin.

Question 19

Listeria monocytogenes propels itself through mammalian host cells using:

Accepted Answer

Listeria monocytogenes uses host cell actin and other cytoskeletal proteins to propel itself through mammalian host cells. This process is known as actin-based motility.

Question 20

Exotoxins can be denatured by iodine to form __________ which are useful in vaccines.

Accepted Answer

The answer of Exotoxins can be denatured by iodine to...

Quiz 31: Infection and Pathogenicity