Describe the type of hemolysis shown by the pathogen Staphylococcus aureus pictured here.

Question

Petri dish showing clear zones around Staphylococcus aureus colonies indicating beta-hemolysis on blood agar.

Accepted Answer

Hi, everyone. And welcome back. Next question says, what type of hemolysis is demonstrated by the bacterium? Streptococcus pyogenes when grown on a blood ger plate. A alpha hemolysis B beta hemolysis, C gamma hemolysis or D delta hemolysis. Well, let's recall that we can use blood agar as a differential media to tell the difference between different streams. Yeah. And that's because it has to do with how the bacterial cultures being grown on. It affect the red blood cells in the plate. Or I should say the red blood cells in the medium and particularly the different streptococcus strains can be distinguished in this way. So we have streptococcus pyogenes. What type of mosses do we have? First of all, right off the bat, let's just rule out delta hemolysis hemolysis. This is not a name for anything. So this is just a fake answer choice. So our answer is that the strip pyogenes demonstrates choice B beta analysis. And this would represent the complete lysis of the red blood cells with the result that you'll actually see a white or colorless ring around the colonies where those red blood cells have been destroyed. Our other answer choices uh a alpha hemolysis is when you have partial lysis, the red blood cells. And in the course of this partial lysis, um hemoglobin is partially broken down into methemoglobin. And the visible result of this is that you see a greenish color rather than a white ring around the colonies. So this is characteristic of streptococcus pneumonia and of some viridans varieties of streptococcus. So you can see where this different result can help you distinguish which strain of streptococcus bacteria you are looking at. And then finally gamma hemolysis just means no lysis occurs despite the name hemolysis in there. And so therefore, there's no change to the agar since you're not affecting the red blood cells. So I see not the answer we're looking for either. So once again, what type of hemolysis is demonstrated by streptococcus pyogenes when you grow it on blood agri plate choice B beta hemolysis. See you in the next video.

Describe the type of hemolysis shown by the pathogen Staphylococcus aureus pictured here.

Verified video answer for a similar problem:

Key Concepts

Hemolysis Types

Staphylococcus aureus Characteristics

Blood Agar as a Diagnostic Medium