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Phenylethyl alcohol agar
- encourages gram positive growth
- inhibit by phenytylethyl alcohol= gram negative
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Mannitol Salts Agar
- poor or no growth= inhibited by NaCl= not staph
- good growth= organism is not inhibited by NaCl= staph
- Yellow growth or halo= produces acid from mannitol rementation= possible pathogenic S. Aureus
- Red growth (no halo)= doesn't ferment mannitol. no reaction
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MacConkey Agar
- poor growth= inhibited by crystal violet/bile
- good growth= not inhibited by crystal violet/bile= gram -
- pink to red w/ or without preciptate= produces acid from lactose fermentation= possible coliform
- growth is colorless= doesn't ferment lactose. no reaction= noncoliform
-
Eosin Methylene Blue Agar
- poor growth= organismm inhibted= gram +
- good growth= not inhibited= gram -
- pink and mucoid= ferments lactose w/ little acid production= possible coliform
- "dark" (purple to black, w/ or w/o green metallic sheen)= ferments lactose and/or sucrose w/ acid production= porobably coliform
- Colorless (no pink, purple, or metallic sheen)= doesn't ferment lactose or sucrose= noncoliform
-
Hektoen Enteric Agar
- poor growth= inhibited by bile= gram +
- good growth= no inhibited= gram -
- pink to orange= produces acid from lactose fermentation= not shigella or salmonella
- blue-green w/ black precipitate= doens't ferment lactose, but reduces sulfer to hydrogen= possible salmonella
- blue green growht w/o precipitate: doesn't ferment lactose or reduce sulfur= possible shigella or salmonella
-
Xylose Lysine Desoxycholate Agar
- poor growth= inhibited by desoxycholate= gram +
- good growth= not inhibited= gram -
- growth is yellow= organism produces acid= not shigella or providencia
- red growth w/ black center= reduces sulfur to hydrogen sulfide= not shigell or providencia
- Red growth w/o black center= organism does not ferment xylose or ferments xylose slowly= probable shigella or providencia
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