(02/03/15) Staphylococcus spp. (Daniels)

Question 1

the entire genus of staphylococcus is gram ____, non-____, non-______ _____ and are predominantly _____ _____

Answer 1

• positive
• non-motile
• non-spore forming
• facultative anaerobes

Question 2

what test is used to identify if an infection is staph?

Answer 2

catalase test

Question 3

what test is used to identify what specific type of staph an infection is?

Answer 3

coagulase test

Question 4

what type of staph causes the highest burden of disease in people?

Answer 4

S. Aureus

Question 5

if a coagulase test is positive, then the staph is most commonly ______

Answer 5

S. aureus

Question 6

what five conditions have S. Aureus as the causative agent?

Answer 6

• aspiration pneumonia
• UTI
• toxic shock syndrome
• scalded skin syndrome
• food poisoning

Question 7

S aureus lives on and around ____, and 30-40% show prevalence in the ____ _____

Answer 7

• people

- nasal carriage

Question 8

what are the two ways that S aureus can enter the body?

Answer 8

• skin damage (wounds, burns, bites)

- mucosal surface damage

Question 9

what three things does the spread of S aureus in the body depend on?

Answer 9

• bacterial inoculum (more is worse)
• host immunocompetence
• location of infection

Question 10

what 6 populations are at the highest risk for S aureus?

Answer 10

• young children/ elderly
• diabetics
• ppl on immunosuppressive therapy
• HIV+
• dialysis
• IV drug users

Question 11

what three things help S aureus to colonize and invade a host?

Answer 11

• fibronectin binding proteins
• collagen binding proteins (CNA)
• clumping factors (bind fibrinogen)

Question 12

when S aureus attacks, _____ induce inflammation and release _____ to try to kill bacteria, which in turn, attracts other _____ that can actually do damage to the tissue

Answer 12

• PMN’s (neutrophils)
• ROS (reactive oxygen species)
• cytokines

Question 13

what are the 3 virulence factors of S. Aureus?

Answer 13

• polysaccharide capsule
• Protein A (blocks antibody function)
• pore-forming toxins (pop PMN’s)

Question 14

what is the disease that is manifested by staphylococcal toxins that is when the toxins cause the layers of the epidermis to separate? (does this by separating the ______ proteins in the skin)

Answer 14

staphylcoccal scalded skin syndrome (SSSS)

-desmosomes

Question 15

TSST-1 is caused by S aureus and is considered a _______ which causes an unregulated _______ response by activating high numbers of _____ and _____.

Answer 15

• superantigen
• inflammation
• CD4
• T-cells

Question 16

causes toxic shock syndrome

Answer 16

TSST-1 (superantigen)

Question 17

during staphylococcal FOOD POISONING, the bacteria is considered an ______ rather than an _____.

Answer 17

• intoxication (much more severe)(rapid onset)

- infection

Question 18

during staphylococcal FOOD POISONING, if you cook the food the heat will kill the ____ but not the _____ they have formed

Answer 18

• bacteria

- toxin

Question 19

what antimicrobial drugs are used against S aureus?

Answer 19

penicillin binding proteins (PBP’s)

Question 20

what strand of staph S aureus is resistant to penicillin binding proteins?

Answer 20

methicillin resistant S Aureus (MRSA)

Question 21

MRSA frequently carries the _____ ____ to other drug classes

Answer 21

resistance genes

makes the body resistant to many types of drugs

Question 22

what antimicrobial drugs is most commonly used against MRSA? (since penicillin and most others do not work)

Answer 22

vancomycin

Question 23

what are the three most common sites of MRSA infection?

Answer 23

• nose
• axilla
• groin

Question 24

how long can people carry MRSA after it is diagnosed?

Answer 24

up to 4 years

Question 25

regarding MRSA, less that ____% of the general population carry it, but up to ____ % of healthcare professionals do

Answer 25

• 1%

- 15%

Question 26

what is the most effective method to prevent the spread of MRSA?

Answer 26

wash your hands