selective and differential media
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
Selective and Differential Media
EMBSelective 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.
MSA with Staph aureus
Mitis Salivarius Agar
Mitis Salivarius
Agar
Mitis Salivarius Agar
BLOOD AGAR: Enrichment media, and Differential
Fish Eye Colonies of
Enterobacter on blood agar
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
Antibiotic Sensitivity
Organism is resistant to the antibiotic
Organism is susceptible to the antibiotic
To make 5 quadrants, draw a Y and then add 2 more lines like a mustache.
Antibiotic Sensitivity: Check zone diameters on given table
Organism is resistant to the antibiotic
Organism is susceptible to the antibiotic
Organism has intermediate resistance to the antibiotic
Coagulase Test:Differentiates S. Aureus from S epidermidis
Positive:S. aureus
Negative:S. epidermidis