Damage by microbial toxins

Question 1

What are the 3 mechanisms that damage the host during infections?

Answer 1

Cell death
Damaged caused by host responses
Alteration of the metabolism of host cells by toxins

Question 2

______ of host cells occurs via growth of pathogen within host cells, cell-mediated immunity, and membrane-damaging toxins

Answer 2

Lysis of host cells

Question 3

________ damage causes cell death (free radical-induced lipid peroxidation).

Answer 3

Cell membrane

Question 4

Damage caused by host responses via ________ due to exaggerated adaptive immune response = hypersensitivities

Answer 4

Uncontrolled inflammation

Question 5

______
–healthy response-increased blood supply (redness)
-increased vascular permeability (edema)
-chemotaxis (infiltration by phagocytes and lymphocytes)

Answer 5

Inflammation

Question 6

______ hypersensitivity = allergy but can lead to anaphylaxis and shock

Answer 6

Type I hypersensitivity

Question 7

______ hypersensitivity = bound antibodies leading to complement and leukocyte activation to surfaces

Answer 7

Type II hypersensitivity

Question 8

______ hypersensitivity = bound antibodies leading to complement and leukocyte activation to soluble molecules, then immune complex deposition (e.gin glomeruli)

Answer 8

Type III hypersensitivity

Question 9

______ hypersensitivity = inflammation by purely CMI responses (not antibodies)

Answer 9

Type IV hypersensitivity

Question 10

What Ig and type of cell is seen in Type 1 hypersensitivity?

Answer 10

Mast cell and IgE

Question 11

Microbial product or component that can injure another cell or organism at low concentrations

Answer 11

Toxins

Question 12

What are the 3 ways toxins act?

Answer 12

Modulation of targets inside a host cell
Action in the extracellular matrix
Action on surface of a host cell

Question 13

T/F: Toxin production and disease consequences vary widely among pathogenic bacteria

Answer 13

True

Question 14

T/F: Like transposons, many toxin-encoding genes are carried on plasmids or temperate bacteriophage genomes (easy to transfer to other, non-toxigenic bacteria).

Answer 14

True

Question 15

Once in a host that is integrated in via bacteriophage genome integrated in V. cholerae genome: ____ and _____ encode the proteins that comprise cholera toxin

Answer 15

ctxA and ctxB

Question 16

______ -secreted by pathogens that Modulate targets inside a host cell

Answer 16

Exotoxins

Question 17

_______ -injected into host cells contact-dependent Modulate targets inside a host cell

Answer 17

Type III cytotoxins

Question 18

______ are secreted by Type I or II secretion systems

Answer 18

Exotoxins

Question 19

What are the 3 common features of exotoxins?

Answer 19

1. A-B toxins (2 components)
2. Require activation (proteolysis or reduction of disulfides)
3. Many are ADP-ribosyltransferases

Question 20

Which domain of exotoxins _______ is the binding domain?

Answer 20

B domain

Question 21

Which domain of exotoxins _______ is the enzymatic “active” domain?

Answer 21

A domain

Question 22

_____ domain of exotoxins also mediates the entry of the _____ domain into the host cell

Answer 22

B domain; A domain

Question 23

What compound in the action of diphtheria toxin inhibits translocation reaction of protein synthesis?

Answer 23

ADP-Ribosyl-EF-2

Question 24

_______ include collagenases, hyaluronidases, DNases , streptokinase (Streptococcus pyogenes) activates plasminogen (converts to plasmin) and help microbes spread

Answer 24

Exoenzymes

Question 25

Protection against exotoxins A. Immunization with _____

Answer 25

toxoids

Question 26

Protection against exotoxins B. Treatment with ______passive immunization

Answer 26

antitoxins