Gram Stain

Rod

Cocci

Catalase Test

Positive Result = Bubbling
(organism produces catalase)

MSA Test

Result: Growth, yellow medium.
(can ferment mannitol)

BAP Test

Result: β-hemolysis
(clear halo surrounding colonies)

Staphylococcus aures

Result: Growth, no color change.
(cannot ferment mannitol)

BAP Test

Result: Non (y)
(no change to surrounding medium)

Staphylococcus epidermis

Negative Result= No bubbling
(organism does not produce catalase)

MSA Test

Result: Inhibited
(cannot withstand high salt concentration)

BAP Test

Result: β-hemolysis
(clear halo surrounding colonies)

Streptococcus pyogenes

Result: α-hemolysis
(greenish halo around colonies)

Streptococcus pneumoniae

Rod

MAC Test

Result: Bright pink colonies
(positive result for lactose fermentation)

EMB Test

Result: Metallic Green color on medium
(positive result for lactose fermentation)

SS Test

Result: Mostly inhibited
(but can have some pink colonies)
-if pink, indicates lactose fermentor

TSI Slant Test

Result (indicated by Slant/Butt/Gas/H2S):

A/A/v/-

-Yellow/acidic = A
-Pink/alkaline = K
-Gas bubble in medium = + CO2/H2 production
-Black precipitation = + for H2S production
-Variable results = V

Citrate Test

Result = Negative
(Indicated by no color change from green)

Escherichia coli

Result: Dark Purple color on medium
(positive result for lactose fermentation)

SS Test

Result: Mostly inhibited
(but can have some pink colonies)
-if pink, indicates lactose fermentor

TSI Slant Test

Result (indicated by Slant/Butt/Gas/H2S):

A/A/v/-

-Yellow/acidic = A
-Pink/alkaline = K
-Gas bubble in medium = + CO2/H2 production
-Black precipitation = + for H2S production
-Variable results = V

Citrate Test

Result = Positive
(Indicated by bright blue color change)

Klebsiella pnemoniae

Result: Colorless colonies
(negative result for lactose fermentation)

EMB Test

Result: Colorless colonies (coloration of medium)
(Non-lactose fermentation)

SS Test

Result: Colorless colonies with black centers
(Non-lactose fermentor, but the black centers
suggest H2S gas production)

TSI Slant Test

Result (indicated by Slant/Butt/Gas/H2S):

K/A/-/+

-Yellow/acidic = A
-Pink/alkaline = K
-Gas bubble in medium = + CO2/H2 production
-Black precipitation = + for H2S production
-Variable results = V

Citrate Test

Result = Positive
(Indicated by bright blue color change)

Salmonella enterica

Result: Colorless colonies
(Non-lactose fermentor)

TSI Slant Test

Result (indicated by Slant/Butt/Gas/H2S):

K/A/v/-

-Yellow/acidic = A
-Pink/alkaline = K
-Gas bubble in medium = + CO2/H2 production
-Black precipitation = + for H2S production
-Variable results = V

Citrate Test

Result = Negative
(Indicated by no color change from green)

Yersinia enterocolitica