Gram positive

Catalase positive

staph

micrococci

Catalase neg

strep

Beta hemolysis

go to pyr

alpha hemolysis

opochin disc

non hemolytic

bile esculin

PRY bactracin disc

(b hemo)

combines with

DMAC to form a bright red color if positive

colorless if neg

pos pyr

group A strep

(strep pyogenes)

negative pyr

(B hemo)

do a CAMP test

Pos CAMP

group b strep

(Strep Agalactiae)

neg pyr

bile esculin test next

Bile esculin

(b hemo, neg CAMP)

Orange=no reaction

Black Growth in 40% in bile and hydrolyze esculin= pos

Pos bile esculin

PYR(NACL) next

Neg bile esculin

strep (not A, B, D)

Pos PYR NACL

enterococcus

neg PYR NACL

group D strep

Optochin disc sensitive

strep pneumo

Optochin disc resistant

bile esculin next

neg bile esculin

PYR NACL next

Neg bile esculin

viridans group

PYR NACL pos

enterococcus

PYR NACL neg

group D

bile esculin non hemo neg

nonhemolytic strep

Catalase Test

Positive test shows rapid production of bubbles

• Staphylococcus sp. & Micrococcus sp.

Negative test will show no production of bubbles

• Streptococcus sp. & Enterococcus sp

Slide Coagulase

Positive test shows agglutination

– Indicates Staphylococcus aureus

• Negative results confirmed

• Indicates CNS

Tube Coagulase

Positive clot formation

– Indicates S. aureus

• Negative results confirmed

Novobiocin Susceptibility

Zone sizes measured

• Staphylococcus saprophyticus

• Resistant (< 16 mm)

• Other Coagulase negative staphylococcus species

• Sensitive (>16 mm)

PYR Hydrolysis

Staphylococcus aureus is PYR

negative

– Staphylococcus lugdunensis is PYR

positive

Rapid Ornithine Decarboxylase

Positive reaction: Dark purple to violet color

– Indicates S. lugdunensis

– Negative reaction: No development of color

(remains pale yellow to light grayish purple or

development of yellow color)

– Indicates probable Staphylococcus sp

other than S. lugdunensis

Microdase Test

Blue-purple color within

30 sec

Micrococcus

Negative: No color within 30 sec

• Staphylococcus

Bacitracin/Taxo A Susceptibility

Bacitracin Resistant

Growth up to the edge of the disk

Staphylococcus

Bacitracin Sensitive

Zone size > 10 mm around disk

Micrococcus

Glucose Utilization

xidative: produce acid

(yellow) in presence of O2:

Micrococcus

Fermentative: produce acid in

presence or absence of O2:

Staphylococcus