Exercise 21 - Stepyococci And Enterococci

Question 0

What major test differentiates staph vs strep

Answer 0

Catalase test using hydrogen peroxide

Bubbles = staph

No bubbles = strep

Question 1

Gram stain reaction, size, shape, and arrangement of strep

Answer 1

Purple

Cocci

Strepto (chain)

Question 2

Know the flow chart for differentiating the different strep bacteria. You do not have to memorize the names of each species at the end of the flow chart

Answer 2

Ok

Question 3

Know which test distinguish the different species of: (flow chart tells you)

Beta hemolytic strep
Alpha hemolytic strep
Gamma hemolytic strep

And hat the + or - results are for all these tests

Answer 3

Yes

Question 4

Biochemical pattern for streptococcus pyrogens and streptococcus pneumoniae

Answer 4

Hi

Question 5

Be able to read all media for + or - reactions

Answer 5

Eek

Question 6

Flow chart for Gram + cocci:

Step 1

Answer 6

Hemolysis on blood agar

Question 7

Flow chart for Gram + cocci:

Beta Hemolytic:

Next step?

Results of this test?

Answer 7

Bacitracin test

+ = Beta Streptococcus Group A

• = Non Group A Streptococcus

Question 8

Flow chart for Gram + cocci:

Alpha Hemolytic:

What’s the next step?

What do the results mean?

Answer 8

Optochin test

\+ =  S = Streptococcus pneumoniae
- = R = Viridans Streptococcus

Question 9

Flow chart for Gram + cocci:

Gamma hemolytic:

What’s the next step?

What do the results mean?

Answer 9

Bile Esculin test

\+ = continue on with 6.5% salt tolerance test
- = Viridans Streptococcus

Question 10

Flow chart for Gram + cocci:

Gamma hemolytic:

Bile Esculin +:

What’s the next step?
What do the results mean?

Answer 10

6.5% salt tolerance test

\+ = Enterococcus spp
- = Non-Enterococcus (group D Streptococcus)

Question 11

Blood Agar:

Bacitracin:

What is the purpose of this test

What do the results mean

Answer 11

Differentiate Beta Hemolytic strep species

Zone of inhib = greater than 10mm S - positive for Streptococcus (Group A Beta hemolytic strep)

Zone of inhib = less than 10mm R (others)

Question 12

Blood agar:

Optochin:

What is the purpose

What do the results mean

Answer 12

Differentiate Alpha Hemolytic Strep species

Greater than 14mm S - positive for Streptococcus Pneumoniae

Less than 14 mm R (others)

Question 13

Salt tolerance broth:

What types of test is this?

What are its ingredients

What does it select for

Answer 13

Selective, differential

S - 6.5% NaCL
D - glucose and brom cresol purple

Different strep species

Question 14

Salt tolerance broth:

What is its purpose

What are the + and - results

Answer 14

Differentiate gamma hemolytic strep species

+ = color change to yellow (acid changing BCP from purple to yellow); + Turbidity

• = no color change, no Turbidity (still purple)

Question 15

What is the only hemolytic pathway that requires an extra test if positive at the first test

Answer 15

Gamma hemolytic

Question 16

Bile Esculin Slant:

What type of test is this

Answer 16

Differential

Question 17

Bile Esculin Slant:

What is the purpose of this test

What are the + and - results

Answer 17

Differentiate gamma hemolytic strep species

\+ = color change to dark
- = no color change

Question 18

Brain/heart infusion agar slant:

What type of test is this

What does it select for

Answer 18

Enrichment

For fastidious Strep

Question 19

Brain/heart infusion agar slant:

What is its purpose

What are the + / - results

Answer 19

Encourage growth
Catalase test: differentiates Staph vs Strep

\+ = bubbles (Staph)
- = no bubbles (Strep)