Gram + cocci: Staphylococci

Question 1

1) catalase + producing bacteria and facultatively anaerobic
2) non-motile, non-sporeforming, glucose fermenter
3) normal inhabitant of the skin, mucous membrane and intestine

Answer 1

Staphylococci

Question 2

What is the family of staphylococci

Answer 2

Staphylococcaceae

Question 3

Rare strains are fastidious requiring (3)

Answer 3

1) Carbin dioxide
2) hemin
3) menadione for growth

Question 4

What are exempted staphylococci

Answer 4

1) S. saccharolyticus
2) S. aureus subspecies
3) S. anaerobius (obligate anaerobes, catalase negative)

Question 5

What is microscopic appearance of to staphylococci?

Answer 5

Spherical cells that appear in clusters, some singly

Question 6

Culture used on a staphylococci

Answer 6

• BAP - colonies (4-8mm) on agar plate appear creamy, white or light gold
• buttery looking
• others have gray colonies
• B-hemolytic (S. aureus) (complete clear zone)

Question 7

It uses 0.04 units bacitracin; performed on BAP or MHA

Answer 7

Bacitracin

Question 8

What is the results of bacitracin for Micrococci and Staphylococci?

Answer 8

Micrococci - susceptible

Staphylococci- resistant

Question 9

Size of the result of Micrococci in the bacitracin

Answer 9

> or equal to 10 mm zone of inhibition

Question 10

1) most virulent spp.
2) coagulase +
3) chiefly responsible for the various skin, wound and deep tissue infections due to trauma or abrasion to the skin or mucosal
4) furuncles and impetigo (boils/pigsa)

Answer 10

Staphylococcus aureus

Question 11

3 types of nasal carriers associated with S. aureus

Answer 11

1) persistent carriers
2) intermittent carriers
3) noncarriers

Question 12

A nasal carrier that harbor a single strain for a long time

Answer 12

Persistent carriers

Question 13

A nasal carrier that harbor various strain overtime

Answer 13

Intermittent carriers

Question 14

A nasal carrier that do not harbor any organism

Answer 14

Noncarriers

Question 15

Associated diseases and infections in S. aureus (7)

Answer 15

1) toxin-induced disease (SSS or TSS)
2) bacteremia/sepsis
3) UTI
4) acute bacterial endocarditis
5) cutaneous infections
6) osteomyelitis
7) septic arthritis

Question 16

1) a toxin-induced disease where there is an exfoliative dermatitis
2) primarily in newborns and previously healthy children

Answer 16

Scalded skin syndrome (SSS)

Question 17

1) a toxin-induced disease that is rare but potentially fatal, multi system disease characterized by a sudden onset of FEVER, CHILLS, VOMITING, DIARRHEA, MUSCLE ACHES and RASH
2) can quickly progress to hypotension and shock

Answer 17

Toxic shock syndrome (TSS)

Question 18

5 cutaneous infections

Answer 18

1) folliculitis
2) furuncles (boils)
3) carbuncles
4) impetigo
5) purulent abscess

Question 19

A mild inflammation of hair follicles or sebaceous glands

Answer 19

Folliculitis

Question 20

1) are large, raised, superficial abscesses

2) can be an extension of folliculitis

Answer 20

Furuncles

Question 21

1) develop from multiple furuncles which may progress to deeper tissues
2) patients may have fever and chills (systemic infections)

Answer 21

Carbuncles

Question 22

1) is a superficial cutaneous infection characterized by CRUSTY LESION and VESICLES surrounded by a red border
2) common in children

Answer 22

Impetigo

Question 23

Secondary to bactemia

Answer 23

Osteomyelitis

Question 24

An associated disease/infection usually in children

Answer 24

Septic arthritis

Question 25

Staphylococci patients are ______

Answer 25

Bleeders

Question 26

12 enzymes and toxins produced by S. aureus

Answer 26

1) coagulase
2) hyaluronidase
3) staphylokinase
4) lipase
5) DNAse and Phosphatase
6) beta-lactamase
7) enterotoxins
8) leukocidin/Panton-Valentine Leukocidin
9) hemolysin
10) exfoliatin A and B/Epidermolytic toxin A and B
11) toxic shock syndrome 1 enterotoxin F/Pyogenic exotoxin
12) protein A

Question 27

1) it coagulates the fibrinogen in plasma
2) promotes the formation of a fibrin layer around staphylococcal abscess thereby protecting the bacteria from phagocytosis
3) forms coagulase-CFR complex

Answer 27

Coagulase

Question 28

What is the (+) result of the coagulase

Answer 28

Clumping/coagulates

Question 29

A thermostable thrombin-like molecule that forms coagulase-CFR complex

Answer 29

Coagulase-reducing factor

Question 30

2 type of coagulase

Answer 30

1) cell-bound/clumping factor

2) unbound coagulase/free coagulase

Question 31

1) is bound to the cell wall
2) causes bacterial cells to agglutinate in plasma
3) it clots human, rabbit or pig plasma

Answer 31

Cell bound coagulase/clumping factor

Question 32

1) an extracellular enzyme not bound to the cell wall
2) cause clot formation when bacterial cells are incubated with plasma
3) free from cell wall

Answer 32

Unbound coagulase/free coagulase

Question 33

1) it enhances invasion and survival in tissue
2) breaks down hyaluronic acid
3) bonds cells together and renders the intercellular spaces passable to pathogens

Answer 33

Hyaluronidase (spreading-factor enzyme)

Question 34

1) opposite of coagulase

2) fibrinolytic activity; dissolves fibrin clot

Answer 34

Staphylokinase (fibrinolysin)

Question 35

1) produced by both coagulate + and coagulase - staphylococci
2) essential for survival in sebaceous areas of the body
3) important in the formation of furuncles, carbuncles and boils

Answer 35

Lipase (fat-splitting enzyme)

Question 36

1) it lowers viscosity of exudates, giving the pathogen more mobility
2) destroys DNA

Answer 36

DNAse and Phosphatase

Question 37

1) breaks down penicillin and other beta-lactam drugs
2) 90% or more of clinical staphylococci isolates are resistant to penicillin as a result of enzyme production
3) cause resistance

Answer 37

Beta-lactamase

Question 38

It inhibits cell wall synthesis

Answer 38

Beta-lactam

Question 39

1) acts as neurotoxins that stimulates vomiting through the vagus nerve
2) produced by 30% to 50% of S. aureus isolates
3) superagents (TSST-1) that have the ability to interact with many T cells, activating an aggressive immune response

Answer 39

Enterotoxins (heat-stable)

Question 40

1) stable to heating at 100 degrees Celsius for 30 minutes
2) resistant to hydrolysis by gastric and jejune like enzymes
3) do not cause odor, change in appearance or taste
4) found in milk products (enterotoxin B)

Answer 40

Enterotoxin

Question 41

T or F: reheating contaminated food will not prevent disease

Answer 41

True

Question 42

A Greek word meaning “bunches of grapes”

Answer 42

Staphle