Normal Microbiota Of The Throat

Question 1

What bacteria causes Strep throat?

Answer 1

Streptococcus pyogens.

Question 2

Define hemolysis

Answer 2

Lysis of red blood cells.

Question 3

Why are throat cultures on blood agar instead of TSY agar?

Answer 3

Blood agar more nutritious so it supports the growth of more pathogens and is also deferential to production of enzymes that lyse the red blood cells.

Question 4

When hemolysis occurs what happens in media?

Answer 4

Results in zone of clearing around colonies growing on blood agar.

Question 5

What are the common throat microbiota?

Answer 5

Streptococcus (a hemolytic species) - predominant species. Often appear green on blood agar due to hemolysis.
Streptococcus (B hemolytic species) - S. Pyogenes.
Neisseria and Moraxella - may or may not be hemolytic, often buff colored, somewhat larger then previous two described. Both are oxidase positive and rare gram negative cocci.
Rarer ones pg 66.