BH strep

Question 1

What is extracted during latex agglutination acid extraction?

Answer 1

C-carbohydrate

Question 2

Strep w/ wide-band hemolysis?

Answer 2

Groups A, C, G

Question 3

Role of erythrogenic toxin in disease due to Group A strep

Answer 3

Throat infection due to strain infected w/ a toxin-producing lysogenic bacteriophage leads to scarlet fever

Question 4

Group(s) that are considered universally susceptible to penicillin?

Group(s) that are USUALLY susceptible to penicillin?

Answer 4

Universally: A, C, G

Usually: B

Question 5

Specimen used to diagnose rheumatic fever and/or acute glomerulonephritis?

Answer 5

Serum - detect increased titre of patient Ab to strep antigen

Question 6

Strep that do NOT cause secondary sequelae? Why?

Answer 6

Groups C, G

Often part of normal flora, but still have potential to cause infections

Question 7

AST modifications to Kirby-Bauer disc testing for Group A/B?

Answer 7

Use blood agar MH (BAMH)/CO2 20-24 hrs

AND test for inducible clindamycin resistance (D-test)

Question 8

Strep that are reproted by their Lancefield group(s) (no speciation)?

Answer 8

Groups C, G

Question 9

Main virulence factor of S. agalactiae?

Answer 9

Capsule

Question 10

Group A: TxA, CAMP, PYR?

Answer 10

TxA: POS
CAMP = NEG
PYR = POS

Question 11

Lancefield grouping is only useful as an ID tool for __________ BH strep

Answer 11

large colony BH (A, B, C, G)

Question 12

Lancefield strep grouping is reliable for speciation of which BH strep?

Answer 12

Groups A and B only

Question 13

Strep species/group that is never considered normal flora?

Answer 13

S. pyogenes (Group A)

Question 14

Role of M proteins in disease due to Group A strep

Answer 14

Antigenically similar to heart muscle => autoimmune response after respiratory infection

Also associated w/ streptococcal toxic shock-like syndrome

Question 15

Group B strep may cause these 2 infections in women after delivery or abortion

Answer 15

Puerperal sepsis

Endometritis

Question 16

Why is PYR test not used alone?

Answer 16

Only a confirmatory test - many bacteria are PYR+

Question 17

Strep that may have an orange centre if they produce a carotenoid pigment?

Answer 17

S. agalactiae (Group B strep)

Question 18

Abiotrophia and Granulicatella are called _________ variant streptococci and must be supplied with a ________ disc

Answer 18

nutritionally; vitamin B6

Question 19

Group C/G: TxA, CAMP, PYR?

Answer 19

TxA: NEG
CAMP = NEG
PYR = NEG

Question 20

Purpose of stabbing into media/incubating anaerobically when incubating a BAP for strep throat?

Answer 20

Ensure detection of strains that only produce streptolysin-O (SL-O)

Question 21

Group B: TxA, CAMP, PYR?

Answer 21

TxA: NEG
CAMP = POS
PYR = N/A

Question 22

What strep are women screened for in the 3rd trimester?

Answer 22

S. agalactiae (Group B strep)

Question 23

Disease in which S. aureus and S. pyogenes cannot BOTH be implicated in?

Answer 23

Pharyngitis (strep throat)

Question 24

What is erysipelas?

Answer 24

A type of superficial cellulitis, often confined to the face

Question 25

Due to a bacteriophage conferring erythrogenic exotoxin ability to a strain of streptococci

Answer 25

Scarlet fever

erythrogenic strains of toxin positive bacteriophages infecting S. pyogenes.

Question 26

Thought to be associated with antigenic similarity of M protein and patient tissue, notably heart muscle

Answer 26

Rheumatic fever

Question 27

“skin, crusty area near nose/lip” suggests what disease?

Answer 27

Impetigo