Staphylococcus and Streptococcus Labs

Flashcards covering key concepts and tests related to Staphylococcus and Streptococcus identification and differentiation.

Mannitol Salt Agar

A selective medium used to differentiate Staphylococcus species based on their ability to ferment mannitol.

Coagulase Test

A biochemical test used to distinguish Staphylococcus aureus from other Staphylococcus species; positive result indicates the presence of coagulase.

Alpha Hemolysis

Partial lysis of red blood cells, typical of certain Streptococcus species, resulting in a greenish discoloration on blood agar.

Beta Hemolysis

Complete lysis of red blood cells, characteristic of some beta hemolytic Streptococci, resulting in a clear zone around colonies on blood agar.

Catalase Test

A test that differentiates Staphylococci (catalase positive) from Streptococci (catalase negative).

Bile Esculin Test

A biochemical test that differentiates Enterococcus and some Streptococcus species based on their ability to grow in the presence of bile and hydrolyze esculin.

Staphylococcus aureus results for Mannitol Fermentation

Positive: yellow coloration on Mannitol Salt Agar due to acid production from mannitol fermentation.

Staphylococcus aureus results for Coagulase Test

Positive: formation of firm clot in plasma.

Staphylococcus aureus results for Catalase Test

Positive: bubbles produced indicating the presence of catalase.

Bile Esculin Test for Streptococcus species

Used to distinguish Group D Streptococcus (Enterococcus) based on their ability to hydrolyze esculin.

Microscopic distinction between Staphylococci and Streptococci

Staphylococci appear as clusters of cocci, while Streptococci appear as chains or pairs.