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Selective and Differential Media. EMB. Selective for Gram negative E.coli has green metallic sheen. No growth of Gram pos Staph aureus. MSA: Selective and Differential. Selective because of salt: only Staph can grow.
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EMB Selective for Gram negative E.coli has green metallic sheen No growth of Gram pos Staph aureus
MSA: Selective and Differential Selective because of salt: only Staph can grow Differential because S. aureus ferments mannitol sugar (turns it yellow) but Staph epidermidis does not ferment mannitol. Note there is no growth or fermentation from M. luteus.
MacConkey’s Agar:Selective and Differential Selective because Gram pos are inhibited by the bile salts. Differential because it has lactose. Gram negs that ferment lactose turn yellow.
Antibiotic Sensitivity Organism is resistant to the antibiotic Organism is susceptible to the antibiotic
Antibiotic Sensitivity: Check zone diameters on given table Organism has intermediate resistance to the antibiotic Organism is resistant to the antibiotic Organism is susceptible to the antibiotic
Positive Coagulase Test:Differentiates S. Aureus from S epidermidis