Cardiovascular Infections 1 MICRO

Question 1

What are the two most common locations for vegetations to form in endocarditis?

Answer 1

• mitral valve

- aortic valve

Question 2

For most bacteria, the first step in developing endocarditis is damage to the heart valve EXCEPT for _______

Answer 2

Staph aureus

Question 3

Steps for the formation of endocarditis:

Answer 3

1. Initial damage
2. Platelet and fibrin thrombus
3. Bacteremia
4. Bacterial adhesion
5. Biofilm formation

Question 4

What are some non cardiac risk factors associated with infective endocarditis?

Answer 4

• IV drug use
• indwelling IV line
• immunosuppression
• recent dental or surgical procedure

Question 5

What are 3 reasons that you can have blood culture negative endocarditis? (Bacteria does not grow in the blood of someone you think has IE)

Answer 5

1. Previous or current use of antibacterials
2. Intracellular bacteria
3. Maybe NOT IE

Question 6

In right sided endocarditis, the ____ valve is usually affected

Answer 6

Tricuspid

Question 7

Right sided endocarditis is associated with ________ (5)

Answer 7

• IV drug use
• cardiac device infection
• central venous catheters
• HIV
• congenital heart disease

Question 8

Coagulase positive staphylococcus

Answer 8

Staph aureus (food poisoning, skin infections, sepsis)

Question 9

Is staph epidermidis coagulase positive or negative?

Answer 9

COAGULASE NEGATIVE

Question 10

What microorganism do you commonly see in prosthetic valve endocarditis? Is to coagulase positive or negative

Answer 10

Staph epidermidis; coagulase negative

Question 11

_______ is the. Most common cause of both native and prosthetic valve endocarditis

Answer 11

Staph aureus

Question 12

The staph aureus that causes endocarditis is capuslated/non-encapsulated;

Answer 12

Capsulated; usually staph aureus does NOT have a capsule

Question 13

Virulence factor of staph aureus causing endocarditis:

Answer 13

• local site infection
• presence of a polysaccharide capsule
• variety of surface adhesion (clumping factor and fibrinogen binding protein)
• biofilm formation
• hemolysins