STAPHYLOCOCCUS

Question 1

Why is capsular polysaccharide regarded as microcapsule?

Answer 1

Because it can be visualized only by electron microscopy after antibody labelling

Question 2

S. aureus diseases: Exudative dermatitis in rabbits and subcutaneous abscesses in older animals.

Answer 2

Cutaneous staphylococcosis

Question 3

S. aureus and S. epidermidis both has catalase enzyme. True or False?

Answer 3

True

Question 4

Enterotoxins causes what pathological conditions when Staphylococcus is ingested?

Answer 4

Diarrhea and vomiting

Question 5

Superantigens stimulate ____ without normal antigenic recognitions, resulting in the release of cytokines in large amounts causing symptoms of TSS.

Answer 5

T-cells

Question 6

In humans, what are the blood cells that have high affinity to Alpha toxin?

Answer 6

Platelets and monocytes

Question 7

What are the 2 forms of Epidermolytic toxin?

Answer 7

1. ETA
2. ETB

Question 8

If a biomaterial such as IV catheter is in the body for long period of time, fibrinogen proliferates and promote bacterial attachment. True or False?

Answer 8

False, fibrinogen degenerates; do not promote bacterial attachment

Question 9

S. aureus diseases: Stump of spermatic cord after horse castration become infected, enlarged and sclerotic with pockets of pus containing granules similar to actinomycosis​

Answer 9

Botromycosis

Question 10

This is the surface polysaccharide of serotype 5 or 8.

Answer 10

Capsular polysaccharide

Question 11

Other extracellular protein: A plasminogen activator

Answer 11

Staphylokinase

Question 12

Panton and Valentine leucocidin has weak leukotoxicity and hemolytic. True or False?

Answer 12

False, potent leukotoxicity and non-hemolytic

Question 13

S. aureus does not ferment mannitol while S. epidermidis ferments mannitol. True or False?

Answer 13

False, other way around

Question 14

What is the color/pigment of the S. aureus colony?

Answer 14

Golden yellow

Question 15

What is distinction of Panton and Valentine leucocidin from leukotoxin?

Answer 15

Gamma locus

Question 16

Forms/expression of Gamma toxin that are hemolytic and has weak leukotoxin

Answer 16

A and B forms

Question 17

What is the color/pigment of S. epidermidis/S. albus colony?

Answer 17

White

Question 18

S. aureus diseases: Acute septicemia or bacterimia along with toxemia kills lambs; Ixodes ricinus (ticks)

Answer 18

Tick pyemia

Question 19

Other extracellular proteins: Binds with prothrombin in host to form staphylothrombin which causes the activation of the protease activity of thrombin resulting to conversion of fibrinogen to fibrin and formation of clot in plasma.

Answer 19

Coagulase

Question 20

Staphylococcus is gram negative. True or False?

Answer 20

False

Question 21

An enzyme that hydrolyzes hyaluronic acid (cementing substance) therefore regarded as spreading factor.

Answer 21

Hyaluronidase

Question 22

Protein A surface protein of S. aureus binds with ____ (antibody) the wrong way by non-immune mechanism and disrupts the organization and phagocytosis; also fixes complement.

Answer 22

IgG

Question 23

S. aureus diseases: Suppurative lesions in cattle, organisms colonize tips of teats

Answer 23

Mastitis

Question 24

Staphylokinase activates ____ ____ ____ which dissolves fibrin clot.

Answer 24

plasmin-like proteolytic activity

Question 25

This enzymatic activity/enzyme is associated with Beta toxin and damages membrane rich in lipid.

Answer 25

Sphingomyelinase C

Question 26

What are the 2 superantigens produced by Staphylococcus?

Answer 26

1. Enterotoxins 2. Toxic shock syndrome toxin 1

Question 27

Where is fibronectin present?

Answer 27

1. Epithelial surface 2. Endothelial surface 3. Blood clots

Question 28

Protein toxins can damage membrane. True or False?

Answer 28

True

Question 29

What is the classical test to detect the presence of Beta toxin?

Answer 29

Lysis of sheep RBC, at 4 C-15 C which produces incomplete hot-cold lysis

Question 30

Protein toxins: Two-component toxin that damages membrane of susceptible cells and are produced separately but act together to damage membranes.

Answer 30

Gamma toxin and leucocidin

Question 31

TSST1 is stronger compared to enterotoxin. True or False?

Answer 31

False

Question 32

TSST1 is responsible for 75% of TSS including ____ cases.

Answer 32

menstrual

Question 33

Protein toxins of Staphylococcus are responsible for what aspect during infections?

Answer 33

Symptoms

Question 34

Panton and Valentine leucocidin is an important factor in _____ skin lesions such as _____ when injected _____ in rabbits.

Answer 34

necrotizing; dermonecrosis; subcutaneous

Question 35

What are the different diagnoses of Staphylococcus?

Answer 35

1. Smears 2. Culture on BAP 3. Mannitol salt agar

Question 36

Enterotoxins can cause TSS. True or False?

Answer 36

True

Question 37

This virulence factor promotes attachment to blood clots and traumatized tissues.

Answer 37

Fibrinogen/fibrin-binding (clumping factor)

Question 38

What is the habitat of S. epidermidis?

Answer 38

1. Skin

Question 39

Protein toxins: It causes scalded skin syndrome in neonates with widespread blistering and loss of epidermis.

Answer 39

Epidermolytic (exfoliative) toxin

Question 40

Among the species of Staphylococcus, which is the opportunistic invader?

Answer 40

S. epidermidis

Question 41

It is the fibrinogen-binding determinant on S. aureus cell surface, sometimes referred to as bound coagulase.

Answer 41

Clumping factor

Question 42

S. aureus and S. epidermidis are both salt-tolerant. True or False?

Answer 42

True

Question 43

Most important coagulase-negative staphylococci which is a commensal of the skin

Answer 43

S. epidermidis

Question 44

How many serotypes does enterotoxin have?

Answer 44

6 serotypes: A, B, C, D, E, G

Question 45

Alpha toxin binds to membrane of susceptible cells , its subunits oligomerize to form ____ ____, a central pore thru which cellular contents leak.

Answer 45

hexameric rings

Question 46

What is the traditional marker of S. aureus?

Answer 46

Coagulase

Question 47

Alpha toxin: A complex series of secondary reactions cause release of ____ and ____ which trigger the production of inflammatory mediators that produce the symptoms of ____ ____.

Answer 47

eicosanoids; cytokines; septic shock

Question 48

What type of activity do Epidermolytic toxin induce?

Answer 48

Protease activity

Question 49

Surface proteins promote attachment to host proteins such as _____ and _____ that form part of the extracellular matrix.

Answer 49

laminin and fibronectin

Question 50

Among the species of Staphylococcus, which is most prevalent in dogs and carnivores?

Answer 50

S. intermedius

Question 51

Virulence factor: This promote colonization of host tissues such as those that promote attachment to host.

Answer 51

Surface proteins

Question 52

Protein toxins: Small peptide toxin produced by most strains of S. aureus; has phospholipase

Answer 52

Delta toxin

Question 53

Coagulase and clumping factor are same entities. True or False?

Answer 53

False

Question 54

S. aureus and S. epidermidis both has coagulase enzyme. True or False?

Answer 54

False, only S. aureus

Question 55

Among the species of Staphylococcus, which causes exudative epidermitis in swine therefore requiring a Biotin administration?

Answer 55

S. hyicus subsp. hyicus

Question 56

S. epidermidis produces a characteristic slime called ?

Answer 56

Biofilm

Question 57

Forms/expressions of Gamma toxin that form leukotoxin with poor hemolytic activity

Answer 57

B and C forms

Question 58

Give 5 examples of S. aureus disease.

Answer 58

1. Botryomycosis in horses 2. Mastitis 3. Tick pyemia 4. Facial or periorbital eczema in sheep 5. Purulent synovitis in poultry 6. Cutaneous staphylococcosis 7. Porcine necrotizing staphylococcal endometritis

Question 59

An enzyme of Staphylococcus important in abscesses since it could modify antibacterial lipids and prolong bacterial survival.

Answer 59

Fatty acid modifying enzyme (FAME)

Question 60

The toxin that specifically acts on polymorphonuclear leukocytes

Answer 60

Leukocidin

Question 61

What are the habitats of Staphylococcus aureus?

Answer 61

1. Nasal passages 2. Skin 3. Oral cavity 4. Intestinal tract

Question 62

Protein toxins: Best characterized and most potent membrane-damaging toxin; major virulence factor

Answer 62

Alpha toxin

Question 63

Does TSST1 have emetic activity?

Answer 63

None

Question 64

What is the traditional epidemiological tracing in Staphylococcus?

Answer 64

Phage typing

Question 65

Proteases, lipases, and deoxyribonuclease (DNAse) provide nutrients for bacteria. True or False?

Answer 65

True

Question 66

What are some virulence factor of Staphylococcus that inhibit phagocytosis?

Answer 66

Capsule, immunoglobulin-binding protein A

Question 67

What are the different enzymes of Staphylococcus?

Answer 67

1. Proteases 2. Lipases 3. Deoxyribonuclease (Dnase) 4. Fatty acid modifying enzyme (FAME)