Microbiology Questions on G+ Organisms, Streptococcus Differentiation and Hemolysis

G+ positive vs G- negative organisms

1.Concerning G+ positive, coccus shaped organisms: describe how they differ from G- organisms and how you determine that you are working with a G+.

2.Discuss how you might differentiate between Streptococcus pyogenes and Streptococcus lactis and why it might be important to tell the difference between the two.

3.Discuss the truth or fiction concerning this statement and why it is either true or false:

"I put my organism on a blood plate and it showed beta hemolysis so it must be a Streptococcus of some kind!"

4.You are given a tube of broth that contains two G+ coccus organisms, mixed together. You are told a couple of facts:

1) they are both gamma hemolytic

2) both tolerate 7% NaCL.

Describe your thought process about how and why you would make decisions in the procedure to determine what the identity of each organism is. How close can get to their identities just using the various tests available in our virtual micro lab? List the possible organisms.

5.List and explain the different forms of hemolysis that display on blood agar. Explain why its important to have individual colonies and why hemolysis is often linked to pathogenesis.