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STREPTOCOCCUS

STREPTOCOCCUS. 411 , Lab 5 Amany Niazy. Streptococci. + ve. - ve. All are Gram Positive Cocci arranged in chains (short or long) All are Catalase - ve. Gram Stain. Staphylococci. streptococci. Culture. Fastidious organism  no growth on NA Grows well on BAP

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STREPTOCOCCUS

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  1. STREPTOCOCCUS 411 , Lab 5 AmanyNiazy

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

  6. Alpha Hemolytic Streptococci • Give alpha hemolysis on BAP. • It Can be divided in to 2: • Viridans group • S.pneumoniae

  7. Streptococcus viridans s. pneumoniae

  8. S. PNEUMONIAE Viridans Streptococci • Alpha haemolysis • Pin point colonies • Optochin resistant • Bile Solubility  -ve • Part of normal flora of upper respiratory and GI • Alpha haemolysis • Ring form colonies • Tanslucent or mucoid • Optochin sensitive • Sile solubility  +ve • Not part of NF Not Capsulated Flattened with raised edges Capsulated

  9. Viridans Streptococci S. PNEUMONIAE • GPS in chains • GPC elongated (Lanceolated) diplococci

  10. 1. Optochin Test Always don on a BAP. On the primary culture of isolation plate before incubation Ethylhydrocupreine hydrochloride. Zone of inhibition of 14 mm or more  sensitive S. pneumoniae No zone of inhibition S.viridans

  11. Optochin Disk

  12. .Bile Solubility Test • To test if colonies are lysed by bile salt (such as desoxycholate) or not. • There are 2 ways to do the test : • In a tube • On plate

  13. Bile Solubility in Tube • 2 ml of saline in a tube • Emulsify several colonies of test organism in it • Divide organism suspension in 2 tubes • Add 2 drops of bile salt to one tube and 2 drops of sterile distilled water to the other. • Leave 10-25 mn at RT

  14. Bile Solubility on Plate • Add drop of bile salt to specified part of plate • Incubate at 37C for 10 - 30 min • Colony disappear  +ve • Colony stay  -ve

  15. Rapid Detection of S. pneumoniae Rapid latex and coagglutination tests are available to detect capsular pneumococcal antigen in CSF or other sterile body fluids.

  16. Sensitivity Testing of S. pneumoniae

  17. Thank You

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