EX2 Streptococci - Bailey

Question 1

What type of gram stain is strep

Answer 1

gram +

Question 2

what shape is strep, and what does it form

Answer 2

cocci

chains or diplococci

Question 3

Is strep spore forming?

Answer 3

no, non-spore forming

Question 4

What level of oxygen does strep need to survive

Answer 4

facultative anaerobe; can grow with our without

Question 5

Is strep catalase negative or positive

Answer 5

catalase negative; does not break down H2O2

Question 6

What is the lancefield group test

Answer 6

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

Question 7

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

Answer 7

alpha

Question 8

This type of hemolysis is complete hemolysis with a clear zone

Answer 8

beta

Question 9

In this type of hemolysis there is no some of clearing

Answer 9

gamma

Question 10

What is the most common disease of group A strep

Answer 10

acute pharyngitis; strep throat

Question 11

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

Answer 11

group A strep

Question 12

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

Answer 12

scarlet fever

Question 13

What is the main bacteria of GAS

Answer 13

S. pyogenes

Question 14

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

Answer 14

nonsuppurative sequelae; non-pus forming secondary results of ARF

Question 15

This was fairly common until the mid-20th century

Answer 15

acute rheumatic fever

Question 16

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

Answer 16

pharynx

Question 17

True or False

An ARF infection must invoke an immune response

Answer 17

True; hypersensitivity reaction caused by cross-reacting antibodies

Question 18

True or False

No more than 10% of people are susceptible to ARF

Answer 18

True

Question 19

How can you completely prevent ARF

Answer 19

by treating strep throat with penicillin

Question 20

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

Answer 20

acute post-streptococcal glomerulonephritis (APSGN)

Question 21

APSGN different from ARF how

Answer 21

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

Question 22

True or False

Not all GAS cause APSGN

Answer 22

True

Question 23

How can one encounter GAS infections

Answer 23

they live on skin and mucous membranes

person to person transmission

Question 24

True or False

GAS can penetrate intact skin

Answer 24

False; it cannot penetrate intact skin

Question 25

How do GAS bind to epithelial cells

Answer 25

via adhesions

Question 26

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

Answer 26

Lipoteichoic acid (LTA) Protein F M protein

Question 27

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

Answer 27

lipoteichoic acid

Question 28

This is a high affinity fibronectin binding protein

Answer 28

protein F

Question 29

This is a keratinocyte (outer skin) adhesion

Answer 29

M protein

Question 30

What determines how a GAS infection spreads

Answer 30

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

Question 31

This breaks down fibrin, disrupting clot formation

Answer 31

streptokinase

Question 32

What do bacteria use to avoid phagocytosis

Answer 32

antiphagocytic factors

Question 33

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

Answer 33

M protein

Question 34

This is a mucoid capsule

Answer 34

hyaluronic acid capsule

Question 35

This inactivated phagocyte chemotaxin

Answer 35

C5a peptidase

Question 36

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

Answer 36

M protein

Question 37

What makes M protein so hard to target

Answer 37

There are nearly 100 serotypes

Question 38

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

Answer 38

false; they are not the same

Question 39

What does the hyaluronic acid capsule do

Answer 39

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

Question 40

This will destroy hyaluronic capsules

Answer 40

hyaluronidase

Question 41

True or False | GAS invokes intense inflammatory response in tissues

Answer 41

True

Question 42

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

Answer 42

superantigens

Question 43

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

Answer 43

True

Question 44

Where do GBS inhabit

Answer 44

lower GI and female genital tract

Question 45

What does GBS cause

Answer 45

neonatal spesis and meningitis | cellulitis, arthritis

Question 46

GBS has what type of capsule

Answer 46

polysaccharide (different from GAS)

Question 47

Which groups are included in other β-hemolytic strep

Answer 47

groups C, G, and F

Question 48

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

Answer 48

M protein bind fibrinogen secrete extracellular enzymes

Question 49

Which groups also has a hyaluronic acid capsule

Answer 49

C

Question 50

Group D strep undergoes what type of hemolysis

Answer 50

α or γ

Question 51

What describes group D strep and where is it found

Answer 51

enterococci and nonenterococci | normal flora of GI and genitourinary tract

Question 52

What are considered "world's toughest pathogenic bacteria"

Answer 52

enterococci

Question 53

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

Answer 53

antibiotic synergism | vancomycin

Question 54

What type of bacteria and conditions are a result of nonenterococci

Answer 54

S. bovis subactue bacterial endocarditis bacteremia

Question 55

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

Answer 55

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

Question 56

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

Answer 56

viridans strep

Question 57

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

Answer 57

True

Question 58

Viridans strep consists of what strep family

Answer 58

S. mutans (causes caries)

Question 59

S. mutans thrives on which substance

Answer 59

sucrose; fermenting it, causing acid