Streptococcus Vs. Staphylococcus 2

Question 1

Beta

Answer 1

Complete hemolysis

=Ability to secrete exotoxin and Lyse RBC

Question 2

Beta is positive for…

Answer 2

Hemolysins

Question 3

What two infections Beta is found in (hemolysins)

Answer 3

Group B strep

Streptococcus pyogens

Question 4

Alpha

Answer 4

Partial hemolysis

= no lysing just changing color of RBC to yellow

Question 5

The two infections that Alpha is found in are…

Answer 5

Streptococcus mutans

Streptococcus pneumonia

Question 6

Gamma

Answer 6

No hemolysis

Not pathogenic

Question 7

What is the mechanism of action of hemolysin

Answer 7

A hemolysin protein is made up of 7 single peptides. Each contains a hook that wiggles into an exposed phospholipid bilayer from a cell membrane.

Once all 7 are hooked, they form a non-specific pore into our RBC (specifically cells that have iron) this pore allows water in causing the cell to eventually lyse.

Question 8

Is Staphylococcus areus transient or resident member of microflora?

Does it cause to disease in everyone who is harboring it?

Answer 8

Transient

No, only 30 to 50%

Question 9

Coagulase

Answer 9

An enzyme that clots blood

Makes proteins in the blood insoluble and becomes a mesh to form a clot

Question 10

Why is coagulase an advantage to staphylococcus?

Answer 10

So the immune cells won’t get to it by staphylococcus secreting coagulase and creating a mesh to protect them

Question 11

Staphylokinase

Answer 11

Dissolves the clot

During the time of coagulase, they replicate and decrease the chance of getting consumed.

Question 12

What two virulence factors of staphylococcus aureus work together?

Answer 12

Coagulase and staphylokinase

Question 13

What are the two common localized infections caused by Staphylococcus aureus?

What is the portal of entry for those two?

Answer 13

Skin- pus filled/wet
Impetigo-dry/yellow crust

Portal of entry= broken of the skin

Question 14

Can staphylococcus infections be systemic?

Answer 14

YES!

NEVER RULE OUT STAPH

Question 15

Describe scalded skin syndrome

Answer 15

Most common in neonates

Staphylococcus aureus gets into blood via umbilical stump

If staphylococcus can secrete Exfolative Toxin, the epidermis will separate from the dermis

Question 16

What causes toxic shock syndrome (TSS)

Answer 16

It is caused by toxin a super antigen and which causes overreactive degranulation of the immune response and causes systemic vasodilation

Question 17

What happens when you have a super antigen that is in your bloodstream?

Answer 17

It causes vasodilation everywhere therefore your blood pressure drops.

In result there is multiple organ failure because you are not able to move blood where it is supposed to be due to vasodilation everywhere

Question 18

Shock is caused by…

Answer 18

Inflammation everywhere, systemically

Question 19

What is a pyrogenic toxin?

Answer 19

A toxin that causes fever and shock

Question 20

Why is pyrogenic toxin called a superantigen?

Answer 20

Because it stimulates everywhere in the body that results to vasodilation due to over reaction of degranulation

Low bp= multiple organ failure

Question 21

True or false, all Staphylococcus aureus cause scalded skin syndrome and toxic shock syndrome

Answer 21

False

Question 22

What is hemolysis?

Answer 22

Is the Lyse of red blood cells