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Flashcards in Strep Lab Deck (15):
1

purpose of Optochin test

differentiate Strep pneumoniae

2

minimum zone of inhibition for sensitivity to Optochin

14mm

3

purpose of Bile Esculin

differentiate Group D streptococcus

4

percent of bile in bile esculin agar

40%

5

bakit positive ang group D sa bile esculin?

it can hydrolyze esculin to esculetin

6

reaction of esculetin with ferric citrate forms ___

black - brown ppt on agar

7

purpose of 6.5% salt broth test

differentiate group D enterococci

8

positive result of 6.5% salt broth test

turbidity in 6.5% NaCl broth = turbidity in nutrient broth

9

color change @ 6.5% salt broth test when bromcresol purple is added

purple to yellow

10

Which is resistant to both bacitracin and sulfamethoxazole-trimethoprim?
a. group A strep
b. Group B strep
c. neither

b. Group B strep

11

Which is susceptible to bacitracin but not to sulfamethoxazole-trimethoprim?
a. group A strep
b. Group B strep
c. neither

a. group A strep

12

True or false: In bacitracin and sulfamethoxazole-trimethoprim susceptibility test, considered susceptible if the zone of inhibition is >12 mm

false. susceptible pag may zone of inhibition, regardless of size

13

purpose of CAMP reaction

differentiate group B strep

14

What is CAMP factor?

produced by group B strep, enhances lysis of sheep red blood cells by staphylococcal beta hemolysin

15

positive result for CAMP reaction

arrowhead-shaped area of enhanced hemolysis in junction of S.aureus streak and strep isolate