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Flashcards in Pathogens Host Defenses Deck (103)
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31

What does the release of the extracellular enzyme leucocidin target & cause the lysis of?

Leucocytes (white blood cells) produced by staphylococci, streptococci, and some gram neg bacteria

32

What are leucocytes?

White blood cells

33

What do the extracellular proteins, Proteases, do once they are released?

The degrade complement proteins and/or antibodies

34

What produces the extracellular enzyme coagulase?

virulent staphylococci

35

What do coagulase enzymes cause? What does this do?

insoluble fibrin to be deposited on bacterial cells. This blocks the bacteria from the immune system

36

What are invasins?

Surface proteins, or injected proteins, that allow microorganisms to enter cells (invade host cells)

37

What is one major virulence factor of intracellular pathogens?

Invasins

38

How does the invasion of host cells benefit bacterial pathogens?

It protects them against the host immune system and is a good source of nutrients

39

What are 4 examples of pathogens that have invasins?

Mycobacterium, Salmonella, Listeria, Chlamydia

40

In what 4 ways do pathogens modify the properties and behaviors of host cells in order for them to grow inside of host cells?

1. block phagosome maturation (block digestion)
2. Increase size of vacuole
3. Acquire nutrients
4. Block detection of intracellular infection and response (host defense)

41

What is a phagosome?

a vacuole in the cytoplasm of a cell, containing a phagocytosed particle enclosed within a part of the cell membrane.

42

What two type of secretion systems do a lot of gram-negative pathogens use?

Type 3 (T3SS) and Type 4 (T4SS)

43

What does a T3SS do?

It forms a channel through the bacterial cytoplasmic membrean + periplasm + outer membrane + host cell membrane so bacterial proteins can be injected into the host cell cytosol

44

What are the 3 functions of T3SS?

1. Invasion of host cells
2. Block phagosome maturation
3. Take control of host cells

45

How is T4SS different from T3SS?

T4SS does not have a needle-like structure

46

What are T3SS and T4SS's also called?

injectisomes

47

What are toxins?

Extracellular enzymes that cause damage

48

Is toxin production always necessary for an organism to be highly virulent? What else can be the cause of damage to an organism?

No. Damage can be caused by the host's own immune system or be a result of the large # or pathogens present

49

What are the 2 categories of diseases that bacterial pathogens are associated with?

1. Infectious diseases
2. Intoxications

50

What do infectious disease result from?

The pathogen's growth

51

What do intoxication's result from?

The presence of a specific toxin

52

What are 3 examples of infectious diseases?

Pneumonia
Meningitis
Syphilis

53

What is an examples of an intoxication?

food poisoning

54

What 2 categories are toxins divided into?

Exotoxins & endotoxins

55

What is an exotoxin?

A toxin secreted into the surroundings as the bacterial pathogen grows

56

What is an endotoxin?

A toxin that is part of the bacterial pathogen

57

Are exotoxins soluble or insoluble?

soluble

58

When are exotoxins secteted/released?

When the organism is lysed

59

What macromolecule are exotoxins normally?

Proteins

60

What destroys exotoxins?

Heat (heat-liable)