Staphylococcus

Question 1

Produces white colonies that tend to turn a buff-golden color with time.

Answer 1

S. aureus

Question 2

Found in the environment and as members of the indigenous skin microbiota.

Answer 2

Micrococci

Question 3

[5] Most important human pathogens

Answer 3

1. Staphylococcus aureus
2. Staphylococcus epidermis, capitis, hominis
3. Staphylococcus saprophyticus
4. Staphylococcus lugdunensis
5. Staphylococcus haemolyticus

Question 4

a-toxin aka

Answer 4

a-hemolysin

Question 5

It is a protein secreted by almost all strains of S aureus, except coagulase-negative staphylococci.

Answer 5

a-toxin

Question 6

In addition to lysing erythrocytes, can damage platelets and macrophages and cause severe tissue damage.

[toxins]

Answer 6

a-hemolysin

Question 7

It lyses the cytoplasmic membranes by direct insertion into the lipid bilayer to form transmembrane pores.

[toxins]

Answer 7

pore-forming cytotoxin

Question 8

Acts on sphingomyelin in the plasma membrane of erythrocytes and is also called the “hotcold” lysin.

[toxins]

Answer 8

β-Hemolysin

Question 9

Enhanced hemolytic activity on incubation at 37° C and subsequent exposure to cold (4° C).

Answer 9

“hot cold” feature

Question 10

CAMP means

Answer 10

Christie, Atkins, and Munch-Petersen

Question 11

Test performed in the laboratory to identify group B streptococci.

Answer 11

CAMP

Question 12

It binds to a specific cell membrane ganglioside found only in the stratum granulosum of the keratinized epidermis of the skin.

Answer 12

Exfoliatin

Question 13

Exfoliative toxin is also known as?

Answer 13

Epidermolytic toxin

Question 14

It causes the epidermal layer of the skin to slough off and is known to cause staphylococcal SSS, sometimes referred to as

Answer 14

Ritter disease

Question 15

This toxin has also been implicated in bullous impetigo.

Answer 15

Exfoliatin

Question 16

It is considered a virulence marker.

Answer 16

Enzymes

Question 17

[3] Capable of destroying tissue capable of destroying tissue.

Answer 17

1. Protease
2. Lipase
3. Hyaluronidase

Question 18

In the cell wall of S. aureus

Answer 18

Protein A

Question 19

Its ability to bind the Fc portion of immunoglobulin G (IgG)

Answer 19

Protein A

Question 20

Stimulates gastrointestinal symptoms (primarily vomiting)

Answer 20

S. aureus enterotoxins

Question 21

Most commonly caused by enterotoxins A, B, and D

[enterotoxins]

Answer 21

Staphylococcal food poisoning

Question 22

Sometimes G and I are associated with TSS.

[enterotoxins]

Answer 22

Enterotoxins B

Question 23

Has been linked to staphylococcal pseudomembranous enterocolitis.

[enterotoxins]

Answer 23

Enterotoxin B

Question 24

A family of secreted proteins that are able to stimulate systemic effects as a result of absorption from the gastrointestinal tract after ingestion.

Answer 24

Superantigens

Question 25

Menstruating-associated TSS.

Answer 25

Toxic Shock Syndrome Toxin 1

Question 26

Previously referred to as enterotoxin F.

Answer 26

Toxic Shock Syndrome Toxin 1

Question 27

A superantigen stimulating T-cell proliferation and the subsequent production of a large amount of cytokines that are responsible for the symptoms.

Answer 27

TSST - 1

Question 28

Superficial skin infection that typically develops in a hair follicle, sebaceous gland, or sweat gland.

Answer 28

Furuncle or boil

Question 29

Often a complication of acne vulgaris.

Answer 29

Furunculosis

Question 30

Occurs most often on the back of the neck but it may involve other skin sites.

Answer 30

Carbuncle

Question 31

Relatively mild inflammation of a hair follicle or oil gland; the infected area is raised and red.

Answer 31

Folliculitis

Question 32

Repeated attacks of boils.

Answer 32

Chronic Furunculosis

Question 33

Caused by the same strain of S aureus.

Answer 33

Chronic Furunculosis

Question 34

It has been long known as a secondary invader in group A streptococcal pustular impetigo. [staphy]

Answer 34

Staphylococcus aureus

Question 35

Strains of S aureus that produce exfoliatin cause a characteristic form called?

Answer 35

Bullous impetigo

Question 36

A localized form of staphylococcal scalded skin syndrome.

Answer 36

Bulluos impetigo

Question 37

Results from the production of exfoliatin in a staphylococcal lesion. [skin syndrome]

Answer 37

Staphylococcal scalded skin syndrome

Question 38

A bullous exfoliative dermatitis that occurs primarily in newborns and previously healthy young children.

Answer 38

SSS

Question 39

Characterized by a sudden onset of fever, quickly progress to hypotension and shock.

Answer 39

Toxic Shock Syndrome

Question 40

It is most commonly drug induced, but some cases have been linked to infections and vaccines.

Answer 40

Toxic Epidermal Necrolysis (TEN)

Question 41

Can be resolved by the administration of steroids early in the initial stages of presentation, whereas steroids aggravate SSS.

Answer 41

Toxic Epidermal Necrolysis (TEN)

Question 42

Staphylococci that do not produce coagulase are referred to as?

Answer 42

CoNS

Question 43

[2] They are occasional isolates and can be significant pathogens.

Answer 43

S. haemolyticus S. lugdunenesis

Question 44

It is associated mainly with urinary tract infections (UTIs), predominately in adolescent girls and young women.

Answer 44

S. saprophyticus

Question 45

A CoNS occasionally recovered in wounds, septicemia, UTIs, and native valve infections.

Answer 45

S. haemolyticus

Question 46

It has been associated with catheter related bacteremia and endocarditis.

Answer 46

S. lugdunensis

Question 47

Infections caused by this are predominantly hospital acquired.

Answer 47

S. epidermis

Question 48

It is a common cause of health care-acquired UTIs.

Answer 48

S. epidermis

Question 49

UTIs in young women.

Answer 49

S. saprophyticus

Question 50

This organism can be more virulent and can clinically mimic S. aureus infections.

Answer 50

S. lugdunensis

Question 51

It has been known to contain the gene mecA that encodes oxacillin resistance.

Answer 51

S. lugdunensis

Question 52

It appears as gram positive cocci, usually in clusters. [s&m]

Answer 52

Staphylococci

Question 53

It appears as gram positive cocci in tetrads, rather than large clusters. [s&m]

Answer 53

Micrococci

Question 54

Contains salt (7.5%), the sugar mannitol, and phenol red as the pH indicator. [culture]

Answer 54

Mannitol Sal Agar

Question 55

S. aureus that can grow in the presence of salt and ferment mannitol produce colonies surrounded by a? [culture]

Answer 55

yellow halo

Question 56

It is a rapid method to differentiate Staphylococcus from Micrococcus by detection of the enzyme oxidase. [test]

Answer 56

Microdase test

Question 57

This test is used to detect the presence of cytochrome oxidase enzymes. [test]

Answer 57

Catalase test

Question 58

[2] S. aureus produces two forms of coagulase:

Answer 58

1. Bound 2. Free

Question 59

[2] They are require susceptibility testing.

Answer 59

1. S. aureus 2. S. lugdunensis

Question 60

Breaks down the β-lactam ring of many penicillins, most S. aureus isolates are resistant to penicillin.

Answer 60

β-lactamases (penicillinases)

Question 61

Does not require routine antimicrobial susceptibility testing because isolates typically are sensitive to agents commonly used to treat UTI. [staphy]

Answer 61

S. saprophyticus

Question 62

Remains the treatment of choice for MRSA.

Answer 62

Vancomycin

Question 63

A better inducer of mecA-mediated resistance.

Answer 63

Cefoxitin

Question 64

Yellow colonies fermenting mannitol as evident by the yellow color of the agar.

Answer 64

Staphylococcus aureus

Question 65

White colonies, no mannitol fermenting, as evident by the original pink color of the agar.

Answer 65

Staphylococcus epidermidis

Question 66

Bacitracin resistant and Furazolidone sensitive.

Answer 66

Staphylococcus epidermis

Question 67

Bacitracin sensitive and Furazolidone resistant.

Answer 67

Micrococcus

Question 68

MRSA means

Answer 68

Methicillin - Resistant Staphylococci Aureus

Question 69

CAMRSA means

Answer 69

Community Associated Methicillin - Resistant Staphylococcus Aureus

Question 70

HACO - MRSA means

Answer 70

Health care - Associated Community - Onset Methicillin - Resistant Staphylococcus Aureus

Question 71

It is often found only in association with Panton-Valentine leukocidin (PVL). [cytolytic toxins]

Answer 71

δ-Hemolysin

Question 72

Bacitracin resistant and Furazolidone sensitive

Answer 72

Staphylococcus epidermis

Question 73

Bacitracin sensitive and Furazolidone resistant.

Answer 73

Micrococcus

Question 74

How much drop of hydrogen peroxide solution is placed on a slide, and a small amount of the bacterial growth is placed in the solution.

Answer 74

3%

Question 75

It is unstable and breaks down easily on exposure to light.

Answer 75

Hydrogen peroxide

Question 76

A third type of MRSA is termed

Answer 76

HACRO - MRSA or Health care - associated community - onset methicillin resistant Staphylococcus areus

Question 77

To determine the organism’s susceptibility to clindamycin, this test has been used in microbiology laboratories.

Answer 77

Modified Kirby Bauer Test