EX2 Streptococci - Bailey Flashcards Preview

SP14 Microbiology > EX2 Streptococci - Bailey > Flashcards

Flashcards in EX2 Streptococci - Bailey Deck (59):
1

What type of gram stain is strep

gram +

2

what shape is strep, and what does it form

cocci
chains or diplococci

3

Is strep spore forming?

no, non-spore forming

4

What level of oxygen does strep need to survive

facultative anaerobe; can grow with our without

5

Is strep catalase negative or positive

catalase negative; does not break down H2O2

6

What is the lancefield group test

serological classification based on major cell-wall carbohydrate antigens; agglutination = positive

7

This type of hemolysis is partial hemolysis and green discoloration of hemoglobin

alpha

8

This type of hemolysis is complete hemolysis with a clear zone

beta

9

In this type of hemolysis there is no some of clearing

gamma

10

What is the most common disease of group A strep

acute pharyngitis; strep throat

11

These are all diseases of what class of strep;
pyoderma, nectrotizing fasciitis, myositis, childbed fever, and foodborne outbreaks

group A strep

12

What is caused by strep throat and a red skin rash; caused by GAS

scarlet fever

13

What is the main bacteria of GAS

S. pyogenes

14

This can result in the inflammation of heart/joints, polyarthritis/caritis, severe vascular scarring

nonsuppurative sequelae; non-pus forming secondary results of ARF

15

This was fairly common until the mid-20th century

acute rheumatic fever

16

If there is an infection in this location, ARF may form, but if not, then no ARF

pharynx

17

True or False
An ARF infection must invoke an immune response

True; hypersensitivity reaction caused by cross-reacting antibodies

18

True or False
No more than 10% of people are susceptible to ARF

True

19

How can you completely prevent ARF

by treating strep throat with penicillin

20

This is active inflammation in the glomeruli of the kidneys; urine is smoky due to proteins, leukocytes, and erythrocytes, renal failure --> dialysis

acute post-streptococcal glomerulonephritis (APSGN)

21

APSGN different from ARF how

can follow skin infections
susceptibility common
recurrent attacks are rare
not reliably prevented by penicillin

22

True or False
Not all GAS cause APSGN

True

23

How can one encounter GAS infections

they live on skin and mucous membranes
person to person transmission

24

True or False
GAS can penetrate intact skin

False; it cannot penetrate intact skin

25

How do GAS bind to epithelial cells

via adhesions

26

What type of adhesions doe GAS use to bind to epithelial cells

Lipoteichoic acid (LTA)
Protein F
M protein

27

This is found in the cell envelope of many gram + bacteria, making them sticky, and it binds to fibronectin

lipoteichoic acid

28

This is a high affinity fibronectin binding protein

protein F

29

This is a keratinocyte (outer skin) adhesion

M protein

30

What determines how a GAS infection spreads

how the infection was acquired; skin/mucous membrane tend to stay localized but deep tissue tends to spread rapidly

31

This breaks down fibrin, disrupting clot formation

streptokinase

32

What do bacteria use to avoid phagocytosis

antiphagocytic factors

33

This is the most important antiphagocytic factor, it is central to pathogenesis and required for virulence

M protein

34

This is a mucoid capsule

hyaluronic acid capsule

35

This inactivated phagocyte chemotaxin

C5a peptidase

36

This blocks complement from binding to the cells, inhibits the formation of opsonizins, and forms a dense coating on bacterias surface

M protein

37

What makes M protein so hard to target

There are nearly 100 serotypes

38

True or False
The hyaluronic acid capsule on strep is that same as the polysaccharide capsule on staph

false; they are not the same

39

What does the hyaluronic acid capsule do

makes strep "slippery," interfering with phagocytosis
ARF isolates are heavily encapsulated

40

This will destroy hyaluronic capsules

hyaluronidase

41

True or False
GAS invokes intense inflammatory response in tissues

True

42

These can mimic the effects of endotoxins, are responsible for the red rash of scarlet fever, and produce streptococcal toxic shock syndrome

superantigens

43

True or False
Group B strep is more common, though less notorious than group A

True

44

Where do GBS inhabit

lower GI and female genital tract

45

What does GBS cause

neonatal spesis and meningitis
cellulitis, arthritis

46

GBS has what type of capsule

polysaccharide (different from GAS)

47

Which groups are included in other β-hemolytic strep

groups C, G, and F

48

What do groups C, G, and F have in common with and B

M protein
bind fibrinogen
secrete extracellular enzymes

49

Which groups also has a hyaluronic acid capsule

C

50

Group D strep undergoes what type of hemolysis

α or γ

51

What describes group D strep and where is it found

enterococci and nonenterococci
normal flora of GI and genitourinary tract

52

What are considered "world's toughest pathogenic bacteria"

enterococci

53

What is required for killing of enterococcil; which antibiotic are some resistant against

antibiotic synergism
vancomycin

54

What type of bacteria and conditions are a result of nonenterococci

S. bovis
subactue bacterial endocarditis
bacteremia

55

True or False
Nonenterococci can grow in high salt and are killed by penicillin

False; enterococci can grow in salt, but are not killed by penicillin

56

This is the most common cause of subacute bacterial endocarditis, and 30-60% of the oropharyngeal flora, is α-hemolytic

viridans strep

57

True or False
Enterococci have a low virulence, but are very resistant

True

58

Viridans strep consists of what strep family

S. mutans (causes caries)

59

S. mutans thrives on which substance

sucrose; fermenting it, causing acid