TESTS FOR IDENTOIFICATION OF NON-HEMOLYTIC STREPTOCOCCI

Question 1

Differentiate Enterococcus (+) species from Non-enterococcus species (-)

Answer 1

PYRase (PYR test)

Question 2

positive result in PYR test:

Answer 2

Pink to cherry-red color after the addition of the color developer

Note: Group A strep is also PYR positive

Question 3

Distinguish Group D streptococcus and Enterococcus from other Lancefield groups.

Answer 3

Bile-Esculin Agar

Question 4

Differentiate group D streptococci from nonenterococci

Answer 4

6.5% Salt Broth (Salt tolerance test)

Question 5

Group D enterococci is (salt tolerant/salt intolerant)

Answer 5

Group D enterococci is salt tolerant (+)

Question 6

Group D enterococci (E. faecalis, E. faecium)

Bile-Esculin Agar:
6.5% Salt Broth:
PYRASE:

Answer 6

Group D enterococci (E. faecalis, E. faecium)

Bile-Esculin Agar: (+) growth with blackening
6.5% Salt Broth: (+)
PYRASE: (+)

Question 7

Group D non-enterococci (S. bovis, S. equinus)

Bile-Esculin Agar:
6.5% Salt Broth:
PYRASE:

Answer 7

Group D non-enterococci (S. bovis, S. equinus)

Bile-Esculin Agar: (+)
6.5% Salt Broth: (-)
PYRASE: (-)

Question 8

Not group D

Bile-Esculin Agar:
6.5% Salt Broth:
PYRASE:

Answer 8

Not group D

Bile-Esculin Agar: (-)
6.5% Salt Broth: (-)
PYRASE: (-)