Unit 1- Staphylococcus

Question 1

Genus Staphylococcus

Answer 1

gram positive cocci in clusters, facultative anaerobe, non-motile, non-spore forming, catalase positive, grow on high salt media

Question 2

Cultures for growth

Answer 2

Mannitol salt agar and blood agar

Question 3

Mannitol Salt Agar

Answer 3

Selectively supports the growth of gram positive staphylococcus, enterococcus, listeria, and micrococcaceae and inhibits streptococcus and gram negatives

Question 4

S. Aureus on Mannitol salt

Answer 4

Ferments Mannitol and turns agar from red to yellow

Question 5

S. epidermidis on Mannitol salt

Answer 5

Does not ferment and agar remains the same

Question 6

S. aureus on purple agar base

Answer 6

Turns agar yello

Question 7

Beta hemolysis

Answer 7

Complete hemolysis, dangerous species, turns blood agar clear

Question 8

Alpha hemolysis

Answer 8

Incomplete hemolysis, turns agar green

Question 9

Gamma hemolysis

Answer 9

No hemolysis or change in media

Question 10

Staphyloxanthin

Answer 10

Carotenoid pigment in S. aureus indicating more pathogenicity

Question 11

Catalase

Answer 11

Test for antioxidant, Staphylococcus will be positive

Question 12

Coagulase

Answer 12

Causes serum to clot, positive strains are more pathogenic

Question 13

Staph Habitat

Answer 13

Commensal in skin and tubular orifices

Question 14

Risk of Staph Infection

Answer 14

Other infection, shearing in sheep, haircut in dogs, or nutritional imbalance

Question 15

Body structures for adhesion

Answer 15

Cell wall, protein A, binding factors, and capsule or slime layer

Question 16

Protein A

Answer 16

Binds the arms of IgG antibodies, blocks immune response and opsonization

Question 17

Enzymes for invasion

Answer 17

Hyaluronidase, catalase, coagulase, staphylokinase, lipase, protease, beta-lactamases

Question 18

Staphylokinase

Answer 18

Lyses fibrin in blood clots to disperse itself

Question 19

Toxins

Answer 19

Hemolysin, cytolytic toxins, exfoliative toxins, toxic shock syndrome toxin, enterotoxins

Question 20

Toxic Shock Syndrome Toxin

Answer 20

Causes shock and superantigens activating 20% of T cells

Question 21

Pathogenesis

Answer 21

Adhesion on host cell, biofilm formation, intracellular invasion, inflammation and abscess formation, and invasion of blood and systemic spread

Question 22

Abscess Rupture

Answer 22

Leads to bacteremia and diverse organ infection in organs that receive higher cardiac output

Question 23

Coagulase Positive Species

Answer 23

S. aureus, S. hyicus, S. pseudointermedius, S. shleiferi

Question 24

Coagulase Negative Species

Answer 24

S. chromogenes, S. felis, S. epidermidis

Question 25

Staphylococcus aureus

Answer 25

Causes pus in abscess, dermatitis, mastitis, septicemia, endocarditis, meningitis, and osteoarthritis in many species

Question 26

Staphylococcus pseudointermedius

Answer 26

Most common in pets, causes pyoderma, pyometra, and otitis externa

Question 27

Staphylococcus hyicus

Answer 27

Most common in pigs, causes greasy pig disease

Question 28

Scalded Skin Disease

Answer 28

S. aureus causes exudative epidermitis in humans

Question 29

Greasy Pig Disease

Answer 29

S. hyicus causes exudative epidermitis in pigs

Question 30

Pyoderma

Answer 30

S. aureus and S. schleiferi causes pyoderma of dogs and cats

Question 31

Otitis externa

Answer 31

S. pseudointermedius and S. aureus causes otitis externa in dogs and cats

Question 32

Mastitis

Answer 32

S. aureus and S. chromogenes are commensal at teat orifices and can cause mastitis in ruminants

Question 33

Largest cause of mastitis

Answer 33

Staphylococcus

Question 34

Tick Pyemia

Answer 34

S. aureus causes pus-forming bacteria to spread in the blood stream after abscess caused by tick bites ruptures

Question 35

Botryomycosis

Answer 35

Cluster of grape bumps on skin of horses caused by S. aureus

Question 36

Bumble Foot

Answer 36

Pyogranulomatous infection in the foot of poultry caused by S. aureus

Question 37

Resistance

Answer 37

Methicillin and vancomycin

Question 38

Control and prevention

Answer 38

Improve hygiene and wellbeing: improve immunity, tick control, clean wounds, carefully groom

Question 39

Control and prevention in dairy

Answer 39

Hygiene at milking time, dry cows, separate infected cows, cull cows with chronic mastitis, prevent reinfection