Chapter 15 Microbial mechanisms of pathogenicity Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is pathogenicity?

A

the ability for a pathogen to cause disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Know why virulence is important.

A

virulence is how dangerous/deadly a pathogen is
(the degree of pathogenicity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three major routes of microbial entry?

A

mucus membranes
skin
parenteral route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how can microbes gain entry through our mucus membranes?

A

through the respiratory tract (breathing)
gastrointestinal tract (swallowing)
genitourinary tract (urethra)
conjunctive (eyes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how can microbes gain entry through our skin?

A

hair follicles
sweat glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can microbes gain entry through our parenteral route?

A

microbes get put directly into skin (via puncture wounds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the number 1 portal of microbial entry?

A

mucus membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How would someone get microbial entry from the respiratory tract?

A

breathing in through nose or mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How would someone get microbial entry from the gastrointestinal tract?

A

food, water, contaminated fingers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How would someone get microbial entry from the genitourinary tract?

A

sexually contracted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How would someone get microbial entry from the conjunctiva?

A

from rubbing eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is the preferred route important?

A

certain bacteria cannot survive on/in some regions of the body but can flourish in other

(for example, Streptococcus pneumonia cannot cause disease if swallowed but can flourish if inhaled.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the definition of ID50?

A

infectious dose for 50% sample populations (measures virulence of a microbe)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the definition of LD50?

A

lethal dose for 50% of sample population (measures potency of a toxin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The lower the ID, the more or less virulent?

A

the lower the ID, the more virulent it is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The lower the LD, the more or less virulent?

A

the lower the LD, the more virulent it is

17
Q

How do capsules help bacteria evade the immune system?

A

prevents phagocytic cell from adhering to the bacterium

18
Q

If a bacteria has a capsule, is it virulent or avirulent? Vice versa?

A
  • capsule = virulent
  • no capsule = avirulent
19
Q

what is the effect of coagulases and how it assists with survival of pathogens within the human body?

A

clot the fibrinogen in blood which protects against phagocytosis and other defenses

20
Q

what is the effect of kinases and how it assists with survival of pathogens within the human body?

A

break down blood clots from by body in order to release trapped bacteria to wherever it needs to go

21
Q

what is the effect of hyaluronidase and how it assists with survival of pathogens within the human body?

A

hydrolyses hyaluronic acid which holds together connective tissue, allowing for the organism to spread and also causes tissue blackening (gas gangrene)

22
Q

what is the effect of collagenase and how it assists with survival of pathogens within the human body?

A

breaks down collagen which allows for the spread of gas gangrene

23
Q

what is the effect of IgA proteases and how it assists with survival of pathogens within the human body?

A

destroys IgA antibodies which helps to inhibit immune response

24
Q

3 ways by which bacteria can damage host cells?

A
  1. using host nutrients (like iron)
  2. causing direct damage (lysing/destruction of host cells)
  3. produce toxins (inhibit host cell protein synthesis)
25
Q

what is hemolysin?

A

kill erythrocytes by forming protein channels

26
Q

Why do bacteria kill red blood cells?

A

To gain iron within and around RBCs

27
Q

What is a siderophore?

A

proteins secreted by pathogens which bind to iron more strongly than host cells

28
Q

What is the only example of an endotoxin? Which type of bacteria produces endotoxin?

A

Lipid A
only within gram negative

29
Q

Which type of bacteria is most likely to secrete exotoxins?

A

both gram negative and gram positive can excrete exotoxins
but gram positive is most likely to

30
Q

what are the names of all three exotoxins?

A

superantigens
membrane-disrupting toxins
A-B toxins

31
Q

what is a superantigen

A

exotoxin causing intense immune response due to cytokines from host cells

32
Q

what is a membrane-disrupting toxin?

A

exotoxin causing lysis of host cells by disrupting plasma membrnaes

33
Q

what is A-B toxin?

A

exotoxin that contains an enzyme/binding component causing inhibition of protein synthesis

34
Q

Which 6 toxins were fungal instead of bacterial?

A

ergot
aflatoxin
mycotoxin
phalloidin
amanitin
lysergic acid diethlylamide(LSD)

35
Q

what are the Salem witch trials thought to be caused by?

A

ergot released in working fields

36
Q

Know what LAL is and why it is important to the pharmaceutical industry

A

LAL is found in horseshoe crab blood. Its importance is that it is a specific protein that can coagulate around endotoxins allowing for it to test pharmaceutical drugs, hospital equipment that enters our body, and surgical tools for endotoxins