Skin: 4. Dugan : Staphylococci

Front 1

What type of bacteria is staphlyococci?

Back 1

gram positive cocci

Front 2

is staph spore forming?

Back 2

no

Front 3

what type of metabolism does staph use?

Back 3

facultative anaerobes

Front 4

what type of agar do you use for the detection of staph? *** IMPORTANT

Back 4

Mannitol salts agar

because they Grow in presence of high concentrations of salt (NaCl > 7.5%)

Front 5

S. Aureus

Coagulase: +/-?

Back 5

+

Front 6

S. Aureus

Color of colonies?

Back 6

golden yellow

Front 7

S. Aureus

mannitol fermentation?

Back 7

+

Front 8

S. Aureus

Novobiocin

Back 8

S

Front 9

S. epidermidis

Coagulase: +/-?

Back 9

- (negative)

Front 10

S. epidermidis

Color of colonies?

Back 10

White

Front 11

S. epidermidis

Mannitol fermentation?

Back 11

- (negative)

Front 12

Staph saprophyticus causes what kind of infection?

Back 12

urinary tract

Front 13

S. epidermidis


Novobiocin

Back 13

S

Front 14

S saprophyticus

Coagulase: +/-?

Back 14

- (negative)

Front 15

S saprophyticus

Color of colonies

Back 15

white

Front 16

S saprophyticus

Mannitol fermentation?

Back 16

- (negative)

Front 17

S saprophyticus

Novobiocin

Back 17

R

Front 18

What is peptidoglycan?

Back 18

responsible for the shape and rigidity of cell

Front 19

besides providing cell shape/rigidity, what does peptidoglycan do? (with respect to leukocytes)

Back 19

Serves as a chemoattractant for polymorphonuclear leukocytes

Activates complement by the alternate pathway (C3b)

Front 20

what staph causes the most infections in the blood stream?

Back 20

s. aureus

Front 21

what are teichoic acids?

Back 21

- polymers of ribotol or glycerol phosphates

Adherence
In deep seated infections → teichoic acid antibodies (diagnostic)

(look like little hairs on the end of gram positive bacteria, on slide 9)

Front 22

what is the job of teichoic acids?

Back 22

Adherence

In deep seated infections → teichoic acid antibodies (diagnostic

on bacteria

Front 23

how does gram positive bacteria lead to shock?

Back 23

lysis of the bacteria

peptidoglycan and lipoteichoic acids lead to the release of inflammatory cytokines which will eventually lead to shock

Front 24

Gram negative vs. positive

which causes shock?

Back 24

both!

Front 25

what is Protein A and what is its job?

Back 25

protein embedded in the cell wall,

anti-opsonin effect

Binds the Fc portion of IgG leaving the Fab portion free to bind with specific antigen

Front 26

what is Fibronectin-binding protein (FnBP)

Back 26

promotes binding to mucosal cells for staph a

Front 27

what is catalase? why is it important?

Back 27

breaks down hydrogen peroxide [H202] (producing water and oxygen)

released by staph

can be used to determine if staph over strep

Front 28

please compare free and bound coagulase

Back 28

Bound Coagulase – agglutination of S. aureus in citrated rabbit plasma

Free Coagulase – causes clot formation by S. aureus in citrated rabbit plasma (gold standard)

Front 29

abscess formation is associated with what

Back 29

staph infection

due to coagulase

Front 30

what do hemolysins do?

Back 30

have an effect on red blood cells

released by staph

Front 31

what is leukocidin?

Back 31

pore former

creates pores in white blood cells

released by staph

Front 32

what is an enterotoxin?

Back 32

exotoxin secreted in the GI tract

there are 6 types (A,B,C,D,E, G)

Resist gut enzymes and low pH
Found in 30-50% of strains
Most common kind of food poisoning in U.S.
Ingestion → vomiting and diarrhea within 2-6 hours

Front 33

you have a 30 people show up with explosive vomiting and diarrhea, they all claim to have come from the same picnic, what is the cause?

Back 33

enterotoxins release from staph (likely aureus)

Front 34

what is the most common kind of food poisoning in the US?

Back 34

enterotoxins from staph

Front 35

what 2 exotoxins behave as superantigens?

Back 35

Toxic Shock Syndrome toxin

Enterotoxin

Front 36

what are superantigens?

Back 36

bind on the side of the binding site btw a MCH and T cell

lead to unregulated T-cell activation

leads to serious damage due to release of cytokines in toxic amounts

Front 37

what is the number 1 cause of bacteremia?

Back 37

Staphyloccus aureus

Front 38

endoccarditis can be caused by which staph?

Back 38

Staphyloccus aureus

Front 39

where do you most often encounter staph on the body?

Back 39

25-50% colonize external nares

Front 40

can staph penetrate the skin?

Back 40

not without damage

Front 41

what is an abscess called in the skin?

Back 41

furuncle or boil → carbuncles

Front 42

what is an impetigo?

Back 42

A single or possibly many blisters filled with pus; easy to pop

normally on face

Front 43

what is cellulitis

Back 43

tissue underneath the skin gets infected

Front 44

are abscesses caused by staph limited to the skin?

Back 44

no, they can spread anywhere

you can even get it in the bone Osteomyelitis

Front 45

what causes Scalded skin syndrome? what population is it normally seen in?

Back 45

Epidermolytic toxins A and B (released from staph a)

normally in infants

Front 46

what do you normally treat minor skin infections with?

Back 46

tetracycline

Front 47

if you have a pt with an abscess, what is an important non pharmacological treatment? **

Back 47

incision and drainage

Front 48

what are the 2 acquired strains of staph. aureus?

Back 48

hospital

community

Front 49

"King Cotton"

Back 49

Expression used by Southern authors and orators before the civil War to indicate the economic dominance of the Southern cotton industry, and that the North needed the south’s cotton. In a speech to the Senate in 1858, James Hammond declared, “You daren’t make war against cotton!...Cotton is king!”

Front 50

what is the most common community acquired strain of staph a?

Back 50

USA300

Front 51

Panton-Valentine-leucocidin is what?

Back 51

pore forming agent released from staph aureus

Front 52

USA300 has what that makes it so strong?

Back 52

Panton-Valentine-leucocidin (PVL)

pore former

Front 53

what do we use to treat USA300 normally? (2 options)

Back 53

trimethoprim

sulfoxazole

Front 54

how do sulfonamides and trimethoprim work?

Back 54

they are folate antagonists

Sulfonamides: Blocks synthesis of dihydropteroic acid

trimethoprim: Blocks synthesis of tetrahydofolate

Front 55

action of Trimethoprim? used to treat?

Back 55

Blocks synthesis of tetrahydofolate

USA300 (community staph. a)

Front 56

action of Sulfonamides? used to treat?

Back 56

Blocks synthesis of dihydropteroic acid

USA300 (community staph. a)

Front 57

a man gets a new hip from replacement surgery, he ends up getting an infection of the joint. what is the cause of this infection?

Back 57

Staphylococcus epidermidis

Front 58

what is Staphylococcus epidermidis

Back 58

Infect prosthetic joints, IV catheters, and heart valves

Capsule (slime layer) adheres to these sites

More resistant to antibiotics than S. aureus

Front 59

a common street trash female comes to your office. She has a UTI. what is the likely cause?

Back 59

Staphylococcus saprophyticus

Front 60

Staphylococcus saprophyticus causes what?

Back 60

UTI (in females)