1. Streptococci

2. Introduction Pyogenic pathogens - nonmotile, catalase negative, Gram positive cocci in chains

3. Freshly isolated Streptococcus 3

6. Catalase test 6

7. Classification Hemolysis on blood agar plates Cell wall group-specific substance Cell wall group-specific substance

8. Hemolysis β hemolytic α hemolytic γ hemolytic (no hemolysis)

9. Lancefield groups A-H and K-U Lancefield groups A-H and K-U

10. S pyogenes( group A) S pyogenes( group A) S agalactiae( group B) S agalactiae( group B) Enterococci( group D) Enterococci( group D) S pneumoniae S pneumoniae Viridans streptococci Viridans streptococci peptostreptococcus peptostreptococcus

11. BACKGROUND Group A beta- hemolytic streptococci (Streptococcus pyogenes) is one of the most commonly encountered pathogens in humans.

12. Streptococcus pyogenes Specimens Specimens Smears Smears Culture Culture Biochemical test Biochemical test

14. Streptococcus pyogenes

16. Bacitracin test

17. Streptococcal tests 17

18. PYR test L-pyrrolidonyl-ß- naphthylamide L-pyrrolidonyl-ß- naphthylamide dimethylaminocinn amaldehyde dimethylaminocinn amaldehyde

19. Hemolysis patterns on blood agar 19

20. Streptococcus agalactiae Group B Chronic bovine mastitis promoted by milking machines slowly progressing inflammation, fibrosis fibrin plugs in smaller milk ducts: loss of milk-producing capacity (agalactia) Neonatal meningitis in humans early onset septicemia (≈ 15% of all neonatal septicemias) late onset: purulent meningitis (average 4.8 weeks after birth) 5 - 10 % of pregnant women are reproductive tract carriers Most infection in newborns Most infection in newborns Asymptomatic colonization of the upper respiratory and genitourinary tract Asymptomatic colonization of the upper respiratory and genitourinary tract

21. Streptococcus agalactiae Asymptomatic colonization of the upper respiratory and genitourinary tract Asymptomatic colonization of the upper respiratory and genitourinary tract Most infection in newborns Most infection in newborns

22. Diagnosis Hydrolyze sodium hippurate Hydrolyze sodium hippurate CAMP test CAMP test

23. Hydrolyze sodium hippurate

24. CAMP test

25.  -hemolytic streptococci 25

26. Streptococcus pneumoniae Gram positive diplococci( lancet-shaped) Gram positive diplococci( lancet-shaped) Possessing a capsule Possessing a capsule Normal inhabitants of the upper respiratory tract Normal inhabitants of the upper respiratory tract

28. Diagnosing Streptococcus pneumoniae 28

29. Optochin test

30. Bile solubility test

31. Viridans streptococci Found in the upper respiratory tract Endocarditis 30-40% of cases due to viridans viridans streptococci

32. Enterococci Part of normal enteric flora Part of normal enteric flora Important species Important species 1. Enterococcus faecalis 2. Enterococcus faecium Grow in the 10˚ C to 45˚ C Grow in the 10˚ C to 45˚ C Typically non hemolytic Typically non hemolytic Grow in the presence of 6.5 % NaCl Grow in the presence of 6.5 % NaCl Hydrolyze esculin Hydrolyze esculin