STAPHYLOCOCCI PT2

Question 1

staphute

Answer 1

bunches of grapes

Question 2

kokkos

Answer 2

berries

Question 3

 Golden grapes
 Catalase- producing
 Facultative anaerobe, except S.
saccharolyticus (obligate anaerobe).
 Non-Motile, Non-spore forming
 Glucose fermenter

Answer 3

CHARACTERISTICS OF STAPHYLOCOCCI

Question 4

 They are normally inhabitants of our
skin, mucous membrane and intestine.
 They are associated with human
infection and colonize various skin and
mucosal surfaces. Under a microscope,
they are spherical cells that appear in
clusters or sometimes singly.

Answer 4

STAPHYLOCOCCI

Question 5

Gastroenteritis, Bacteremia, Sepsis, UTI,
Endocarditis, Boils, Furuncles,
Folliculitis, Impetigo and Osteomyelitis.

Answer 5

CLINICAL INFECTIONS OF STAPHYLOCOCCI

Question 6

VIRULENCE FACTORS OF STAPHYLOCOCCI

Answer 6

Catalase enzymes
- Coagulase
- Hyaluronidase
- Staphylokinase
- Lipase
- DNAse
- Beta-Lactamase
- Enterotoxin
- Hemolysin
- Exfoliative
toxins
- Pyagenic
entoxin
- Protein

Question 7

COAGULASE NEGATIVE STAPHYLOCOCCI

Answer 7

S.epidermidis AND S. saphrophyticus

Question 8

most contaminant in the
instruments for catheterization and
prosthetic heart valve implantation. It is
also called as Bacterial endocarditis

Answer 8

S.epidermidis

Question 9

most commonly
acquired urinary tract infection in
sexually active female

Answer 9

S. saprophyticus

Question 10

Mediates the
breakdown of
hydrogen peroxide
(H2O2 ) into oxygen
and water

Answer 10

CATALASE TEST

Question 11

POSITIVE REACTION FOR CATALASE TEST

Answer 11

cupious bubble formation

Question 12

NEGATIVE REACTION FOR CATALASE TEST

Answer 12

No bubble formation

Question 13

BAP CULTURE Colonies

Answer 13

4mm to 8 mm

Question 14

Appear creamy, white or
light gold or “butter
looking” while other species
may have gray colonies
 Beta haemolytic (S. aureus)

Answer 14

STAPHYLOCOCCI IN BAP CULTURE

Question 15

Best criterion of
Pathogenicity of
Staphylococcus
aureus

Answer 15

COAGULASE TEST

Question 16

Reagent USE IN COAGULASE TEST

Answer 16

Rabbit
plasma

Question 17

Anticoagulant USE IN COAGULASE TEST

Answer 17

EDTA

Question 18

Coagulase Test Two Methods

Answer 18

▫ Slide Method
▫ Tube Method

Question 19

SLIDE METHOD POSITIVE ORGANISMS

Answer 19

▪ Staphylococcus aureus
▪ Staphylococcus lugdunensis
▪ Staphylococcus schleiferi

Question 20

In Slide method: If positive, it will produce

Answer 20

white fibrin clots
in plasma

Question 21

In Slide method: If it is negative, use

Answer 21

tube method to
confirm it before reporting it as negative

Question 22

 Sensitive but definitive method.
 To detect extracellular or free coagulase

Answer 22

TUBE METHOD

Question 23

TUBE METHOD POSITIVE

Answer 23

clot or coagulum formation
after 1 to 4 hrs of incubation

Question 24

In Tube method: ▪ If no clot left at room temp for additional

Answer 24

20 hours

Question 25

Tube method organisms

Answer 25

▫ Staphylococcus hyicus ▫ Staphylococcus intermedius ▫ Staphylococcus lutrae ▫ Staphylococcus delphini ▫ Staphylococcus schleiferi

Question 26

performed to distinguish S.aureus from S. epidermidis and S. saprophyticus

Answer 26

Coagulase test

Question 27

 Conversion of fibrinogen to fibrin.  Fibrin means it will cause clot formation.

Answer 27

PRINCIPLE OF COAGULASE TEST

Question 28

Differentiate the pathogenic staphylococci from non-pathogenic  Mannitol Salt Agar (MSA)

Answer 28

MANNITOL FERMENTATION TEST

Question 29

pH indicator of Mannitol Fermentation test

Answer 29

phenol red

Question 30

positive result in mannitol fermentation test

Answer 30

Yellow S. aureus colonies (surrounded by yellow halo)

Question 31

composition of mannitol fermentation test

Answer 31

1% Mannitol 7.5% salt or sodium chloride phenol red as an indicator

Question 32

Jet black colonies of S. aureus

Answer 32

TELLURITE GLYCINE AGAR

Question 33

S. aureus is resistant

Answer 33

POLYMYXIN SENSITIVITY TEST

Question 34

▫ Differentiate S. aureus from S. intermedius - ▫ Positive: Pink (acetoin or what we call acetyl methyl carbinol)  S.aureus is positive

Answer 34

VOGES-PROSKAUER (VP) TEST

Question 35

Identify pathogenic species of staphylococci that produces Dnase

Answer 35

▪ DEOXYRIBONUCLEASE (DNASE) TEST

Question 36

Culture media used in DNASE

Answer 36

DNA-methyl green agar

Question 37

POSITIVE REACTION FOR DNASE AND POSITIVE ORGANISM

Answer 37

Clear/colorless zone around organism S. aureus

Question 38

 It lowers the viscosity of the exudates giving the pathogen more mobility.  It detects the presence of DNAse.

Answer 38

▪ DEOXYRIBONUCLEASE (DNASE) TEST