Question

What type of hemolysis would one find on a blood agar plate from the oral cavity of a typical healthy human throat?

Answer 1

Blood agar is a solid growth medium that contains red blood cells.

The medium is used to detect bacteria that produce enzymes to break apart the blood cells.

This process is also termed hemolysis.

There are three types of hemolysis, designated alpha, beta and gamma.

Alpha hemolysis is a greenish discoloration that surrounds a bacterial colony growing on the agar.

This type of hemolysis represents a partial decomposition of the hemoglobin of the red blood cells.

Alpha hemolysis is characteristic of Streptococcus pneumonia and so can be used as a diagnostic feature for  the identification of the bacterial strain.

Beta hemolysis represents a complete breakdown of the hemoglobin of the red blood cells in the vicinity of a bacterial colony.

There is a clearing of the agar around a colony.

Beta hemolysis is characteristic of Streptococcus pyogenes and some strains ofStaphylococcus aureus.

The third type of hemolysis is actually no hemolysis at all.

Gamma hemolysis is a lack of hemolysis in the area around a bacterial colony. A blood agar plate displaying gamma hemolysis actually appears brownish.

  

The answer to the given question is Gamma Hemolysis