BACTE LEC FP: STAPHYLO

Question 1

What is the shape and Gram reaction of Staphylococcus?

Answer 1

Perfectly spherical Gram-positive cocci

Question 2

What is the size range of Staphylococcus cocci?

Answer 2

Approximately 0.5 to 1 µm in diameter

Question 3

What is the colony arrangement of Staphylococcus?

Answer 3

They grow in clusters like a bunch of grapes

Question 4

What is the colony pigment of S. aureus?

Answer 4

Golden yellow

Question 5

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

Answer 5

White

Question 6

What is the habitat of S. aureus?

Answer 6

Nasal passages, skin, oral cavity, and intestinal tract

Question 7

What is the habitat of S. epidermidis?

Answer 7

Inhabitant of the skin

Question 8

What is the role of surface proteins in Staphylococcus?

Answer 8

They promote colonization of host tissues

Question 9

What does the fibronectin binding protein promote?

Answer 9

Attachment to epithelial and endothelial surfaces and blood clots

Question 10

What does the clumping factor bind to?

Answer 10

Fibrinogen and fibrin

Question 11

What does the collagen-binding factor help infect?

Answer 11

Indwelling medical devices like IV catheters and prosthetic joints

Question 12

What component inhibits phagocytosis in Staphylococcus?

Answer 12

Capsular polysaccharide and protein A

Question 13

What is the function of protein A in S. aureus?

Answer 13

Binds IgG the wrong way, disrupting opsonization and phagocytosis

Question 14

What is the function of leukocidin?

Answer 14

Toxin that specifically acts on polymorphonuclear leukocytes

Question 15

What is the function of alpha toxin?

Answer 15

It damages membranes and causes leakage of cellular contents

Question 16

What is the function of beta toxin?

Answer 16

It is a sphingomyelinase causing incomplete hot-cold lysis of sheep RBCs

Question 17

What is the function of delta toxin?

Answer 17

It is a phospholipase; its disease role is unclear

Question 18

What is the function of gamma toxin?

Answer 18

It forms a two-part toxin with leukocidin to damage membranes

Question 19

What is the role of Panton-Valentine leukocidin (PVL)?

Answer 19

Potently leukotoxic and involved in necrotizing skin infections

Question 20

What do enterotoxins cause?

Answer 20

Diarrhea and vomiting (staphylococcal food poisoning)

Question 21

What is TSST-1 responsible for?

Answer 21

75% of toxic shock syndrome cases, especially menstrual cases

Question 22

What does the epidermolytic (exfoliative) toxin cause?

Answer 22

Scalded skin syndrome in neonates

Question 23

What is the function of coagulase?

Answer 23

Forms staphylothrombin with prothrombin to activate thrombin and form clots

Question 24

What is the function of staphylokinase?

Answer 24

Activates plasminogen to dissolve fibrin clots

Question 25

What does FAME do?

Answer 25

Modifies antibacterial lipids in abscesses to prolong bacterial survival

Question 26

What is the function of hyaluronidase?

Answer 26

Hydrolyzes hyaluronic acid (cementing substance)

Question 27

What does S. epidermidis commonly infect?

Answer 27

Prosthetic devices and catheters with biofilm production

Question 28

What are the catalase and coagulase reactions of S. aureus?

Answer 28

Catalase and coagulase positive

Question 29

What are the catalase and coagulase reactions of S. epidermidis?

Answer 29

Catalase positive, coagulase negative

Question 30

Which staphylococcus ferments mannitol?

Answer 30

S. aureus

Question 31

What does S. aureus cause in horses?

Answer 31

Botryomycosis

Question 32

What does S. aureus cause in cattle?

Answer 32

Mastitis

Question 33

What does S. aureus cause in lambs?

Answer 33

Tick pyemia

Question 34

What does S. aureus cause in poultry?

Answer 34

Purulent synovitis or bumblefoot

Question 35

What does S. aureus cause in rabbits?

Answer 35

Exudative dermatitis

Question 36

What does S. hyicus cause in pigs?

Answer 36

Exudative epidermitis (Greasy pig disease)

Question 37

What are diagnostic tools for Staphylococcus?

Answer 37

Smear, BAP culture, Mannitol salt agar, Coagulase, DNase

Question 38

Is there an effective vaccine against Staphylococcus?

Answer 38

No effective vaccine

Question 39

What are two resistance factors of Staphylococcus?

Answer 39

Beta lactamase and methicillin resistance (MRSA)