(1/22/15) Streptococci (Bailey)

Question 1

streptococcus sp. is a gram ____ cocci that is composed of chains and is non-_____ forming. it is a _____ ____ and catalase (test) ______

Answer 1

• positive
• spore
• facultative anaerobe
• negative

Question 2

what are the three ways to classify streptococcus?

Answer 2

• hemolysis pattern
• lancefield group
• species (often not necessary)

Question 3

hemolysis pattern that has partial hemolysis and green discoloration of hemoglobin

Answer 3

alpha

Question 4

hemolysis pattern that shows a clear zone of COMPLETE hemolysis

Answer 4

beta

Question 5

hemolysis pattern that has NO zone of clearing

Answer 5

gamma

Question 6

what group of Beta hemolysis streptococci is responsible for causing the most human diseases

Answer 6

A

Question 7

acute pharyngitis, pyoderma, streptococcal pneumonia, necrotizing fascitis, childbed fever, and foodborne outbreaks are all characteristics of which group of streptococcal diseases

Answer 7

A

Question 8

the S progenies in group A streptococci (GAS) are responsible for what two diseases?

Answer 8

• streptococcal acute pharyngitis (strep throat)

- scarlet fever (strep throat + red skin rash)

Question 9

fever that was fairly common until the mid-20th century and is rarely seen in developed countries now. the US outbreaks in the 80’s and 90’s were due to the emergence of virulent strains

Answer 9

Acute Rheumatic Fever

Question 10

where is the only site of infection that is followed by Acute Rheumatic Fever (1-4 weeks past strep throat)

Answer 10

pharynx

Question 11

in reference to acute rheumatic fever, infection must invoke _____ response

Answer 11

immune

-(could be considered an auto immune disease)(no more than 10% of ppl are susceptible)

Question 12

you can completely prevent acute rheumatic fever infection by treating strep throat with a full course of _____

Answer 12

penicillin

Question 13

actue rheumatic fever has a high susceptibility to recurrence, thus ______ antibiotics into adulthood or for life

Answer 13

prophylactic

Question 14

active inflammation in the glomeruli of the kidney that turns urine smokey due to proteins, leukocytes and erythrocytes, and renal failure (dialysis)

Answer 14

acute post-streptococcal glomerulonephritis

Question 15

what are four ways that acute post-streptococcal glomerulonephritis is different that acute rheumatic fever?

Answer 15

unlike ARF

• can follow pharyngitis or pyodermal infections
• susceptibility common
• recurrent attacks are rare
• not reliably prevented by penicillin

Question 16

what ages do not get strep throat?

Answer 16

1-2 year olds

Question 17

____ % of school aged children may carry Group A infections without symptoms

Answer 17

20

Question 18

what two ways does a person encounter group A infections?

Answer 18

• live on the skin and mucous membranes

- person to person transmission (respiratory drops, hand to hand, food, skin wounds….)

Question 19

Group A infections CANNOT penetrate ____ ____

Answer 19

intact skin (enter through bites, wounds, lesions, cuts, abrasions….)

Question 20

in group A infections, bacteria bind to epithelial cells using _____

Answer 20

adhesions

Question 21

what are the three types of adhesions that group A bacteria use?

Answer 21

• lipoteichoic acid (LTA)
• protein F
• M protein

Question 22

type of group A infection adhesion that makes the streptococci sticky and then binds to fibronectin on epithelial cell surfaces

Answer 22

lipoteichoic acid (LTA)

Question 23

type of group A infection adhesion that is a high affinity fibronectin binding protein

Answer 23

protein F

Question 24

type of group A infection adhesion that is a keratinocyte (outer skin) adhesion

Answer 24

M protein

Question 25

what does the spread of a group A infection depend on?

Answer 25

how the infection was acquired

Question 26

if a group A infection was acquired on the skin or mucous membranes, it usually _____ ____

Answer 26

remains localized

Question 27

if a group A infection was acquired through deeper tissue infections then there is _____ ____

Answer 27

rapid spread

Question 28

_____ is an enzyme that binds to the inactive host plasminogen to create a catalytic complex that breaks down fibrin (blood clots)

Answer 28

streptokinase

Question 29

what are three things that aid group A bacteria in avoiding phagocytosis

Answer 29

- M proteins (most important antiphagocytic factor) - hyaluronic acid capsule - C5a peptidase

Question 30

used by bacteria to avoid phagocytosis, is the most important antiphagocytic factor and is required for virulence

Answer 30

M proteins

Question 31

used by bacteria to avoid phagocytosis, is a mucoid capsule and makes the strep slippery, interfering with phagocyte attachment

Answer 31

hyaluronic acid capsule

Question 32

used by bacteria to avoid phagocytosis, it inactivates phagocyte chemotaxin

Answer 32

C5a Peptidase

Question 33

forms a dense coating on bacteria's surface and blocks complement from binding to the cells. it then binds the host complement control proteins

Answer 33

M proteins

Question 34

super antigens that activate macrophages and cause T cells to release cytokines (three types: SpeA, SpeB, SpeC)

Answer 34

streptococcal pyrogenic exotoxins (SPE's)

Question 35

the super antigens of streptococcal pyrogenic exotoxins (SPE's) are responsible for what two things?

Answer 35

- red rash of scarlet fever | - streptococcal toxic shock syndrome

Question 36

Group that is actually more common but less notorious than group A streptococci

Answer 36

B

Question 37

Group B strep inhabit _____ ____ and female _____ ____ and are the leading cause of _____ _______ and _______

Answer 37

- lower GI - genital tracts - neonatal sepsis - menigitis

Question 38

group B bacteria use what type of capsule?

Answer 38

polysaccharide

Question 39

what are three similarities between group A strep and the other group strep?

Answer 39

- M proteins - bind fibrinogen - secrete similar extracellular enzymes

Question 40

Group of strep that is normal flora of GI and genitourinary tracts. has a low virulence and usually accompanies other bacterial infections

Answer 40

D

Question 41

"world's toughest pathogenic bacteria" that grows in high salt concentrations and in bile. is resistant to most antibiotics including penicillin

Answer 41

enterococci

Question 42

_____ _____ is required for effective killing of enterococci

Answer 42

antibiotic synergism (usually between penicillin and aminoglycoside)

Question 43

makes up 30-60% of the oropharyngeal flora, has a low virulence, but is the most common cause of subacute bacterial endocartidis (affects abnormal heart valves) AND IS RESPONSIBLE FOR DENTAL CARIES (mutan group)

Answer 43

viridians Streptococci

Question 44

viridians streptococci produce ____ for adherence

Answer 44

dextrans

Question 45

the surface proteins of viridans streptococci "mutans group" bind salivary _____ on teeth

Answer 45

glycoproteins

Question 46

amounts to ~50% or more of bacteria in plaque

Answer 46

viridians streptococci "mutans group"

Question 47

the viridian's streptococci "mutans group" ferments sugar to ____ ____ which demineralizes the enamel

Answer 47

lactic acid