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Micro Streptococci
Micro106 - Streptococci characteristics & tests
Question | Answer |
---|---|
What are streptococci? | Streptococci are gram-positive cocci that form chains. |
Where are Streptococci commonly found? | Streptococci can be found in the upper respiratory tract and oral cavity. |
What is beta-hemolytic? | The ability to completely destroy red blood cells in blood agar, producing a clear zone around the colony. |
What is alpha-hemolytic? | The partial hemolysis of red blood cells that produces a green or brownish zone around colonies. |
What are viridans? | The alpha-hemolytic group of Streptococci. |
How does the Lancefield group classify streptococci? | The Lancefield groupings classify streptococci based on the carbohydrate antigens associated with the cells. |
What are the characteristics of S.pyogenes? | S. pyogenes is in the A Lancefield group, sensitive to Bacitracin, and beta-hemolytic. |
What are the characteristics of S. pneumoniae? | S. pneumoniae is not part of a Lancefield grouping, is alpha-hemolytic and optochin sensitive. |
What is the classic sign of CAMP test? | An arrowhead formation of hemolysis on a blood agar plate. |