Staph vs Strep lab

Gram+ vs Gram-

MAC

 Staph Strep Entero

BEA

Entero will grow in BEA

  Staph Strep

catalase

staph are catalase positive

   S. aureus S. epidermidis

coagulase/MSA

aureus is coagulase positive

aureus will produce yellow colonies on MSA

non-pathogenic staph will appear pink/red

   Strep pneumoniae Group A strep S. pyogenes Group D strep Strep viridians

BAP

s. pneumoniae = α = green

group A strep + s. pyogenes = β = clear colony border

group D strep + s. viridians = γ = no effect

    s. pyogenes group A strep

bacitracin

s. pyogenes will be inhibited by bacitracin

    s. pneumoniae viridans strep

optochin sensitivity

s pneumoniae will be inhibited

 Salmonella Pseudomonas E. coli

MacConkey's Agar

pseudomonas + salmonella = non-lactose fermenting = clear/beige

E. coli = lactose fermenting = pink

  salmonella pseudomonas

TSA

pseudomonas will be blue