Biol2230 Wk 10 Pt 2

Front 1

Things that fall into chemical portion of virulence factors:

Back 1

Enzymes such as:

-collagenase

-hyaluronidase

-proteases

and

TOXINS

Front 2

How does hyaluronidase help a pathogen invade?

Back 2

it digests the hyaluronic acid of the matrix of connective tissue, allowing it to penetrate deeper. Generally stops once it reaches fibers, (unless it has other enzymes that also digest those fibers)

Front 3

What falls under 'Resist host defenses"?

Back 3

1. resists phagocytosis

2. Gets inside host cell

Front 4

How does a microorg resist phagocytosis?

Back 4

Capsules help a microorg resist phagocytosis. The capsule makes the phagocyte unable to adhere to the microorg, therefore it can't engulf it.

Front 5

How does salmonella resist phagocytosis?

Back 5

It can be engulfed by a phagocyte. However, it has chemicals (enzymes?) that disable lysosomes to hook up with it to digest it so it remains alive, undigested in the phagocyte

Front 6

How does Mycobacterium resist phagocytosis?

Back 6

It can be ingested by a phagocyte, and lysosome can hook up with it. However, since Mycobacterium is acid-fast, it has a waxy layer which makes the lysozyme unable to digest it. So it lives, undigested inside the phagocyte.

Front 7

How does getting inside host cell help a microorg resist host defenses?

Back 7

once inside host cell, a phagocyte will view the cell as 'self' and therefore will not engulf it

Front 8

What types of microorgs can generally use 'getting inside host cell' as a means of resisting host defenses?

Back 8

viruses (olbigate intracellular parasites)

Front 9

At what point in the 'causing infectious diseases' process do we generally know that someone is sick? Why/How?

Back 9

At the 'cause damage' stage

That person will start showing signs and symptoms

Front 10

Even if a person is exhibiting signs and symptoms, what does their immune response usually do?

Back 10

Their immune response usually catches up/kicks it up a notch and wins over the infection

Front 11

What 3 ways does an infectious disease cause damage/3 types of damage?

Back 11

1. localized damage

2. toxins

3. Host-mediated damage/hypersensitivity

Front 12

what does localized damage mean?

Back 12

Localized damage means its harmful effects are generally limited to one part of the body

Front 13

How does a microorg cause localized damage?

Back 13

1. use of available nutrients (thereby 'starving' host cells)

2. enzyme production (that digest host tissues)

Front 14

How does enzyme production cause localized damage?

Back 14

As the infectious microorg grows, it produces enzyme (specific to each pathogen), that can digest host cells/tissues

Front 15

Explain how enzyme production works to cause periodontal disease?

Back 15

a piece of food stuck between teeth allows extra nutrients for normal microbiota that live in gums, causing them to grow rapidly. As they grow, they produce more proteases, that digest protein. Initially these proteases gum tissue causing red, swollen, painful gingivitis. Eventually, if untreated, the proteases can go on to digest ligaments of gums, causing periodontal disease, possibly causing tooth loss and even digestion of jaw bone

Front 16

What is protease?

Back 16

An enzyme that digests proteins

Front 17

Do toxins cause local or distant damage?

Back 17

Either/both

Front 18

What types of toxins can cause damage?

Back 18

1. endotoxins

2. exotoxins

3. others

Front 19

How do endotoxins cause damage?

Signs and symptoms?

Back 19

Once englufed by phagocytes or other cells, cell dies and endotoxins are released into the blood stream. This can cause high fever, blocked blood flow, organ damage etc

Front 20

What type of microorg is capable of causing damage with endotoxins?

Back 20

gram-negative bacteria because they are the ones that have endotoxins

Front 21

What are the signs and symptoms of an endotoxin related infection?

Back 21

high fever

blocked blood flow

organ damage/failure

gangrene

etc

Front 22

What microorganism can produce exotoxins?

Back 22

gram pos, gram neg, fungi etc

almost any cellular metabolic organism can produce exotoxins

Front 23

What type of infection does an exotoxin cause?

Back 23

often causes systemic infections

Front 24

What examples of exotoxin types did we study?

Back 24

neurotoxins

enterotoxins

leukocidins

others

Front 25

What 2 things are unique about exotoxins?

Back 25

-each exotoxin is unique to a particular pathogen

- each exotoxin must attach to specific receptors on host cells to cause damage

Front 26

What two examples of neurotoxins did we study?

Back 26

Clostridium botulinum

Clostridium tetany

Front 27

How does the neurotoxin Clostridium botulinum work?

Back 27

Its exotoxin prevents release of acetocholine at neuro-muscular joint, causing muscles to be unable to contract

sign/symptoms: paralysis, muscle movement problems

Front 28

How does the neurotoxin Clostridium tetany work?

Back 28

its exotoxin affects the inhibitory nerves that help muscles relax. As a result, muscles are constantly contracted/spasming

sign/symptoms: spasms, painful, can die from suffocation if it affects diaphragm; can die fm circulatory failure/heart attack if it attacks heart

Front 29

What do neurotoxins act on?

Back 29

nerves

Front 30

What do enterotoxins act on?

Back 30

intestines

Front 31

signs/symptoms of enterotoxin infection?

Back 31

diarrhea, nausea, vomitting, fever

food poisoning

Front 32

What do leukocidins do?

Back 32

kill WBCs

Front 33

Explain the significance of phagocytes being a WBC as it relates to leukocidins?

What does this result in?

Back 33

Leukocidins can kill phagocytes because they are a white blood cell. As the leukocidins kill off phagocytes, more WBCs are sent to combat the infection, causing more dead WBC and therefore causing pus

Front 34

Signs/symptoms of leukocidins infection?

Two examples of diseases associated with leukocidins

Back 34

pus

Strep throat

Staph infections

Front 35

What is the final way that microorgs can cause damage?

Back 35

via host-mediated damage/hypersensitivity

Front 36

What is host-mediated damage/hypersensitivity?

Back 36

damage is caused by host's own immune response (overreacting)

Front 37

What is the clinical significance of virulence factors?

Back 37

The more a microorg has and/or the more powerful the virulence factor is, the more damage the microorg can cause,

- more host immune response tools will be involved with fighting the infection off

Front 38

Why are we concerned with portals of exit for a microorg infection?

Back 38

It's a concern in regard to public health. One person's portal of exit can transmit the disease to the next person's portal of entry

Front 39

Entry/exit portals: flu:

Back 39

entry: mucous membrane

exit: mucous membrane

Front 40

Giardia entry/exit portals:

Back 40

entry: fecal-oral route

exit: diarrhea

Front 41

What is generally true about the relationship between a disease causing microorg's portal of entry and its portal of exit?

Back 41

- might be same body part

- generally at least the same body system

(ie enters via mouth, exits via anus in form of diarrhea)