3.1.3 Staphylococci Flashcards Preview

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Flashcards in 3.1.3 Staphylococci Deck (27)
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1

List general characteristics of bacteria in the genus Staphylococcus (gram, shape, arrangement, catalase status)

Gram +, cocci, clusters, catalase +

2

Staphylococcus is catalase ____ and oxidase ____

Positive, negative

3

What are some of the dz's caused by staphylococcus?

#1 cause of infective endocarditis, nosocomial bloodstream infections, and orthopedic ones

Septic shock mortality rate is high

4

What is the most virulent species of the Staphylococcus genus?

Staph. aureus

5

What do MSSA and MRSA stand for?

Methicillin-susceptible Staph. aureus

Methicillin-resistant Staph. aureus

6

Most MRSA infections in hospitals are typically acquired where?

CA-MRSA

7

What causes foodborne intoxication with staphylococcus?

Ingestion of heat-stable enterotoxin (transmitted by food handlers)

8

Describe the onset of food intoxication seen with staphylococcus

Rapid onset (within 1-6 h)

9

What are some of the clinical syndromes seen with Staph aureus?

LOL

10

What are the major virulence factors of S. aureus?

4 cytolysins

leukocidins

modulins

Enterotoxins

Adherence factors (Protein A, fibronectin-binding proteins, collagen-binding proteins)

Other secreted enzymes

11

What is the main type of infections is most common with S. aureus?

Skin/soft tissue infection (95%)

-cellulitis, impetigo, abcess/furuncle

12

What this be?

Abscess/furuncle

13

What is this? Which toxin is responsible?

Scalded Skin Syndrome (SSS) - Ritter's syndrome

Exfoliative toxins ETA and ETB

14

What age group is most at risk for SSS?

Children under 5

15

This skin desquamation is a result of which toxin? What is the name of this syndrome?

Toxic Shock Syndrome (TSS) - shock w/n 48 hrs

Superantigen

16

What is the mechanism of TSST-1 toxin?

Binds T cell receptor and MHCII of APC => constituitively active

Leads to massive release of cytokines -> hypotension, shock, and death

17

Infection of bone or bone marrow

Osteomyelitis

18

What cardiac abnormality is associated with S. aureus?

19

What are some of the Respiratory tract infections associated with S. aureus?

Pneumonia, empyema, cystic fibrosis

20

What are the two topical rx options for S. aureus?

Bacitracin (MSSA > MRSA)

Mupirocin (MSSA and MRSA)

21

What are the different rx options for MSSA and MRSA?

22

What morphilogical change is associated with VISA? VRSA?

VISA (Vancomycin-intermediate S. aureus) - thickened cell wall

VRSA (Vancomycin-resistant S. aureus) - acquired resistance plasmid from Enterococci

23

What is the coagulase status of S. epidermidis?

Negative

24

What are some of the opportunistic infections of S. epidermidis?

Primary implant, catheter and prosthetic joints, bacteremia (biofilm)

25

What type of infections is S. saprophyticus famous for?

UTIs in sexually active young women

26

27

What is produced by S. epidermidis that inhibits growth of other gram positiives?

Bacteriocins