Gram-positive Cocci Catalase Negative

Flow Chart

Gram-positive Cocci

Catalase Test

+ Micrococcaceae

– Streptococcaceae

Hemolysis

Beta β GpC Strep

GpA Strep (S. pyogenes)

Alpha α Enterococcus

Strep mitis

Bacitracin Sensitivity

+ GpA Strep (S. pyogenes)

– GpC Strep

Bile Esculin Test

+ Enterococcus

– Strep mitis

Strep pneumoniae

Optichin Sensitivity

+ Strep pneumoniae

– Strep mitis

Gram-positive Cocci Catalase Positive

Flow Chart

Gram-positive Cocci

Catalase Test

+ Micrococcaceae

– Streptococcaceae

Coagulase Test

+ Staphylococcus aureus

– Staphylococcus epidermidis

Micrococcus luteus Micrococcus roseus

Mannitol Fermentation Test

+ Staphylococcus aureus

– Staphylococcus epidermidis

Micrococcus luteus Micrococcus roseus

Growth on Mannitol Salt Agar

Test (MSA)

+ Staphylococcus aureus

Staphylococcus epidermidis

– Micrococcus luteus Micrococcus roseus

Pigmentation Observation

Grey/White

Staphylococcus epidermidis

Golden/White

Staphylococcus aureus

Mustard Yellow

Micrococcus luteus

Hemolysis

Beta β Staphylococcus aureus

Alpha α Staphylococcus epidermidis

Micrococcus luteus Micrococcus roseus

Growth on MSA or

Pigmentation Observation

See Pigmentation Observation to

differentiate

Pale Pink/Rose

Micrococcus roseus

Gram-negative Rods Lactose Positive

Flow Chart

Gram-negative Rods

Lactose Test (KIA or Carbohydrate Fermentation Test)

+ _

IMViC Tests

+ + - - E. coli

- - + +

Motility

+ Enterobacter aerogenes

- Klebsiella

Gram-negative Rods

Lactose Test (KIA or Carbohydrate Fermentation Test)

+ _

Oxidase Test

+ _

Gelatin Test H2S (KIA) Test

+ Pseudomonas aeruginosa

- Alcaligenes faecalis

+

- Shigella flexneri

Urea Test

+ Proteus vulgaris

- Salmonella typhimurium

Gram-negative Rods Lactose Negative

Flow Chart