Section 1: Toxins (clinical bacteriology)

Question 1

Are exotoxins destroyed by heat?

Answer 1

yes, they are made of proteins so they are denatured with heat

Question 2

What are the characteristics of an exotoxin?

Answer 2

toxin that is secreted by G+or G- bacterium

or that leaks into the surrounding fluid following lysis of the bacterial cell

Question 3

Are the targets of exotoxins specific or generalized?

Answer 3

specific, do not usually cause fever or generalized inflammation

Question 4

What are neurotoxins?

Answer 4

exotoxins that act on nerves or motor endplates to cause paralysis

Question 5

What are enterotoxins?

Answer 5

exotoxins that act on gastrointestinal tract to cause diarrhea

Question 6

How do enterotoxins work?

Answer 6

inhibit NaCl secretion or kill epithelial cells resulting in osmotic pull of fluids into lumen

Question 7

What are cytotoxins?

Answer 7

exotoxins that damage variety of cell types by either interfering with cell mechanisms or causing cell lysis

Question 8

What are pyrogenic toxins?

Answer 8

type of cytotoxin that stimulate release of cytokines causing rash, and toxic shock syndrom

Question 9

What are characteristics of endotoxins?

Answer 9

lipopolysaccharide (LPS) that is composed of lipid A, core polysaccharide, O specific polysaccharide
lipid A is toxic portion and is responsible for symptoms associated with the endotoxin

Question 10

What type of bacteria have endotoxins?

Answer 10

LPS is a molecule that is part of the outer membrane in Gram negative bacteria, so it is a fundamental part of the cell

Question 11

Do the endotoxins produce a specific or generalized response?

Answer 11

generalized, the immune response to endotoxin is due to innate immune response

Question 12

What is an opportunistic pathogen?

Answer 12

one that causes infection in an immunocompromised individual or
genetics of the bacteria result in commensalism or pathogenicity