Streptococci

Question 1

3 streps in this lecture?

Answer 1

pyogenes, agalactiae, pneumoniae

Question 2

Is strep an aerobe, anaerobe, or facultative anerobe?

Answer 2

Facultative anerobe

Question 3

How does alpha hemolysis look on blood agar plate?

Answer 3

Green

Question 4

How does beta hemolysis look on blood agar plate?

Answer 4

clear

Question 5

How does gamma hemolysis look on blood agar plate?

Answer 5

Almost like there’s no hemolysis

Question 6

Strep pyogenes is in what Lancefield group?

Answer 6

Group A strep (GAS) and beta hemolytic

Question 7

Strep agalactiae is in what group?

Answer 7

Group B strep (GBS) and also beta hemolytic

Question 8

Strep pneumoniae and strep viridans are in what group?

Answer 8

Untypable using this system, alpha hemolytic

Question 9

Catalase/coagulase tests for strep are?

Answer 9

Negative/negative

Question 10

What are Lancefield antigens?

Answer 10

Characterize Strep on the basis of reaction of antibodies to species specific antigens (serology)

Question 11

Group A strep has what kind of capsule?

Answer 11

Hyaluronic acid capsule

Question 12

What protien is a group A strep virulence factor and can lead to rheumatic heart disease from molecular mimicry?

Answer 12

M protein

Question 13

This Group A strep virulence factor is an adhesin and also a PAMP

Answer 13

Lipotechoic acid (LTA)

Question 14

What virulence factor is strep’s superantigen?

Answer 14

Streptococcal pyrogenic exotoxin A (SpeA)

Question 15

Very common strep infection that occurs in the throats of children

Answer 15

Pharyngitis (strep throat)

Question 16

How do you treat pharyngitis?

Answer 16

Give penicillin to prevent development of ARF

Question 17

What can follow a pharyngeal infection with group A beta hemolytic strep?

Answer 17

Acute rheumatic fever

Question 18

This disease became almost obliterated when docs started washing their hands inbetween delivering babies

Answer 18

Endometritis

Question 19

This strep infection is a pyoderma (purulent skin infection) that is common in children

Answer 19

GAS impetigo

Question 20

Deeper impetigo with ulceration is known as

Answer 20

Ecthyma

Question 21

This streptococcal cellulitis is characterized by erythema and edema with rapidly advancing, well demarcated edges

Answer 21

Erysipelas

Question 22

This strep infection is an acute inflammatory condition of the skin that is deeper than impetigo or erysipelas.

Answer 22

Cellulitis

Question 23

Signs of cellulitis?

Answer 23

Localized pain, erythema, swelling, and heat

Question 24

This streptococcal induced infection is rapidly spreading and very fatal. It is characterized by EXTREME PAIN OUT OF PROPORTION TO THE APPEARANCE OF THE LESION

Answer 24

Necrotizing fasciitis

Question 25

How fast can necrosis spread with necrotizing fasciitis?

Answer 25

1 inch per hour

Question 26

ARF usually develops after

Answer 26

Pharyngitis

Question 27

Guidelines for diagnosis of ARF (acute rheumatic fever) are?

Answer 27

Jones criteria

Question 28

Treatment of strep pyrogenes?

Answer 28

Penicillin

Question 29

Invasive infections by strep pyogenes require what 4 things?

Answer 29

1. you must monitor CO and BP 2. IV infusion for hypotension 3. Renal failure may call for dialysis 4. IV Ig

Question 30

Test for Strep agalactiae (GBS)?

Answer 30

CAMP test

Question 31

Bigtime GBS virulence factor?

Answer 31

Capsule, capsule, capsule

Question 32

Viridans strep is alpha or beta hemolytic?

Answer 32

alpha

Question 33

Where on your body is viridans strep?

Answer 33

oral cavity

Question 34

How do you distinguish strep viridans from pneumococci?

Answer 34

Viridans is resistant to optochin

Question 35

Endocarditis of damaged heart valves usually occurs from?

Answer 35

viridans strep.. after a dental procedure, you get bacteremia

Question 36

These organisms are commensals of the GI tract

Answer 36

Enterococcus

Question 37

Leading cause of nosocomial infection

Answer 37

Enterococcus

Question 38

Why are enterococci a big problem?

Answer 38

They are very proficient at taking up DNA and passing it to other species. Enterococci is probably the reason that S. aureus can be vancomycin resistant