1. Streptococcus
Basmah almaarik
Lab # 6

2. Streptococci
All are Gram Positive Cocci arranged in chains (short or long)
All are Catalase -ve
+ ve
- ve

3. Gram Stain
Staphylococci
Streptococci

4. Culture Fastidious organism  no growth on NA Grows well on BAP
Facultative anaerobe
Grow at 37C need 24 to 48 hour .

5. Streptococcus Classification
Alpha hemolytic
S. viridans
S. pneumoniae
Beta hemolytic:
Group A, B, C, G & D
Lancefield grouping according to antigens in their cell wall
Non-hemolytic:
Enterococcus (formally known as Group D)

6. Hemolytic Streptococci
Alpha hemolysis on BAP (partial hemolysis).
Beta hemolysis on BAP
(complete hemolysis).
No hemolysis on BAP

7. Beta Hemolytic Streptococci
Lancefield grouping depending on antigens in their cell wall, they are classified into groups : A, B, C, D, F, and G.
Facultative anaerobes, grows at 37˚C for 24h.
Need 5-10% CO2

8. Gram Stain

9. Beta Hemolytic Streptococci
Group A (S. pyogenes).
Bacitracin
Group B (S. agalactiae)
CAMP test.
Hippurate hydrolysis.
Group D (Enterococcus)
Grow in high salt conc.
Esculin hydrolysis
Tolerate high tempreture

10. Beta Hemolytic Streptococci
S. Pyogenes(Group A Strep)
S. Agalactiae(Group B Strep)
Catalase –ve.
Bacitracin sensitive.
Catalase –ve.
Bacitracin resistant .

11. S. agalactiae(Group B Strep)
CAMP test:
Streak a Staph.aureus across a blood agar plate.
Inoculate test organism at right angles to it.
The tested organism must not touch the staphylococcal inoculum.
37˚C X hr

12. S. agalactiae(Group B Strep)
S.aureus produce beta- lysin.
S.agalactiae produce extracellular protein CAMP factor.
Both react together synergeticly to produce enhanced haemolysis arrow shape haemolysis.

13. CAMP test +ve and -ve

14. S. agalactiae(Group B Strep)
Hippurate hydrolysis test :
hippuratehydrolase enzyme hydrolizehippurate benzoic acid + glycine
We add ninhydrin reagent which will react with glycine to give us purple color.

15. S. agalactiae(Group B Strep)
Bacterial suspenstion in 1% sodium hippurate
Incubate 2 hours at 37˚C
Add ninhydrine reagent.
Incubate for 10 min.
Purple color  +ve
No purple color  -ve

16. Enterococcus (Group D Strep)
Grow at wide range of temperature 10˚C - 45˚C.
Mainly non hemolytic on blood agar but can show alpha or beta-haemolysis.
Non-fastidious  can grow on nutrient agar.

17. Grow in high slat concentration
Inoculate the organism in a tube of broth containing 6.5% NaCl.
Incubate overnight at 37oC.
Turbid  growth  can tolerate high salt conc  +ve
Clear  no growth  can’t grow in high salt conc.  - ve

18. Esculin Hydrolysis
The organism can hydrolyze esculin and produce black color in the media.
It can also grow in the presence of 40% bile salt.

19. Esculin Hydrolysis
Black color  esculin hydrolysis +ve

20. Growth in high heat. Make a suspension of the organism.
Inoculate on a blood agar (0 time)
Incubate organism suspension in water bath 45˚C X 10 min  sub-culture to BAP
Repeat step 3 tow more times.
Then incubate the BAP 37 ˚C x 24 hr.

21. Rapid identification test for beta-heamolytic streptococci

22. YOUR WORK FOR TODAY Do gram stain and show it to the instructor
Do camp test with group A and B
Do bacitracin sensitivity with group A
Do esculin hydrolysis test with group D
Do salt tolerance test with group D
See instructors hippurate test (Demonestration)
See instructors rapid identification kit for Beta-heamolytic stryptococci (Demonestration)