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24 Cards in this Set
- Front
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hektoen Enteric (HE) agar
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selcts for growth of GM -
other organisms inhibited by bile/dyes in medium |
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HE agar
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differentiates Shigella & Salmonella from each other and other Gm- bacteria
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he agar
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Organism taht ferment latose grow with pink/oragne colored colonies some produce same colodred precipitate in medium. (produces acid)
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HE agar
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Organisms that don't ferment lactose will have blue/green colored colonies. Salmonella may produce blk precip due to reduction of sulfur.
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Biochemical tests for Gm negative bacteria
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Methyl Red (MR)Broth
Phenol RED (PR) broth SimmonsCitrateAGar, Phenylalanine agar, Triple Sugar Iron Agar(TSI),Sulfur-Indole-Motility(SIM) Agar. |
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Methyl Red broth
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test ability of an organism to conduct mixed acid fermentation
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Methyl red reagent
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when added to MR broth has red color change indicates it's acidic and htat mixed acid fermentation has occured.
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Phenol Red (PR) broth
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(has carbohydrate source & ph indicator. Can be prepared with different carbohydrates.
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results of PR broth test
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red-neutral, yellow-acid, and pink when alkaline.
durham tube traps any gas if present |
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PR broth test
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uses carb fermentation to dietinguish among different speceis of bacteria. Produces acid endroducts.jDegreadation of peptones in medium turn it alkaline
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Simmons Citrate Agar
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test ability of organisms to use citrate as a carbon source and ammonium as nitrogen source. contains bromothymol blue.
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Simmons Citrate Agar
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green when neutral
royal blue when alkaline(ph>7.5) . menas Citrate + no change neg for citrate. |
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Phenylalanine Agar
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tests ability of an orgamism to prduce the enzyme phenylalanine deaminase.(P,D.)
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Reagent to Phelalanie Agar
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10% ferric chloride..Reacts to produce green color of growth after drops of ferric cl. and inidcates presnce of Phenylpyruvic Acid and +test for P.D.
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Phenylalanie Agar
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Phenylalanine removes amino group from the produciton of phenylpyruvic acid.
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Triple Sugar Iron Agar (TSI)
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contains lactose,sucrose, small amount of glucose, ferrous sulfate, and Ph inidcator phenol red.
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TSI agar
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used to differenetiate enteric bacteria based on their ability to reduce sulfur & ferment carbs.
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TSI results
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turns lant and butt yellow if it ferments any of the 3 sugars present. If only ferments glucose turns yellow, but slant turns reddue to presence of alkaline end products from peptone catabolism
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TSI results continued
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Anaerobic area of (butt) will not rever to alkaline state and will remain yellow. Absence of any color change-no sugar or peptone catabolism.
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TSI resluts continued
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Gas produced will result in cracks or bubbles-can lift enitire slant from bottom of tube.means able to reduce sulfur, bkl percip formed in agar.(sulfur present)
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Sulfur Indole Motility (SIM) Agar
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stab innoculated with needle. Obligate aerobes grow only at the top. Obigae anaerobes grow only anaerobes grow atthebottom.Faculative grow throughout
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SIM continued
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Organism capale of reducing sulfur will produce a black color change in medium. Some produce Indole rom degradation of tryptophan.
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SIM continued
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If indole present the additon of Kovac's reagent will turn red at the surface of the medium.
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SIM continued
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growth of non-motile organisms only along the inoculating stab line, while motile has outward growth from line.
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