Term
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Definition
| Gram negative rods that can ferment glucose |
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Term
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Definition
| can ferment glucose and lactose (lactose positive) |
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Term
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Definition
| Can only ferment glucose, are lactose negative |
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Term
| Lactose fermentation test |
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Definition
| help distinguish between coliform and non-coliform Enterobacteriaceae |
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Term
| 3 examples of Enterobacteriaceae coliforms (lactose positive) |
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Definition
Escherichia coli
Klebsiella pneumoniae
Enterobacter aerogenes |
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Term
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Definition
Eosin Methylene Blue agar (EMB)
MacConkey ager (MAC)
Triple Soy Iron (TSI) |
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Term
| Eosin methylene blue ager (EMB) |
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Definition
| selective media for gram negatives d.t. dye that is bacteriostatic to gram positives; differential media for lactose fermation because it contains lactose and pH indicators; lactose fermenters take up dye and appear purple/red (E. coli has a green sheen); non-lactose fermenters will appear light colored/transparent. |
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Term
| Light colored/transparent colonies grown on EMB agar |
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Definition
| non-lactose fermenters, lactose negative |
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Term
| Purple to pink/red colonies grown on EMB agar |
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Definition
| Lactose fermenters, lactose positive (Coliforms) |
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Term
| Green metalic cheen colonies on EMB agar |
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Definition
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Term
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Definition
| selective for gram negative, differential media for lactose fermentation, preliminary test for enteric pathogens, lactose fermenters produce acid, grow as pink/purple colonies and turn the agar red, non-lactose fermenters take up dye from media |
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Term
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Definition
| In MacConkey agar select for Enterobacteriaceae and salt tolerant gram negatives, suppresses gram positive |
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Term
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Definition
| suppresses growth of gram positives |
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Term
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Definition
| In MacConkey agar distinguishes between lactose and non-lactose fermenters. Lactose fermenters produce acid, grow as pink/purple colonies, turn the agar red. |
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Term
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Definition
| In MacConkey agar, non-lactose fermenters attack the peptone in the agar creating an alkaline reaction which turns the agar tan. Colonies are white, pink, or transparent. |
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Term
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Definition
| Triple sugar ion, initial differentiation of enteric bacteria. Demonstrates ability of organism to ferment sugars, produce gas, and produce hydrogen sulfide |
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Term
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Definition
| In TSI agar, sugar fermentation causes production of acid products. The TSI media turns yellow under acid conditions and red under alkaline conditions. |
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Term
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Definition
| TSI agar detects the ability of the organism to reduce sulfer to hydrogen sulfide. They iron reacts with the Hydrogen Sulfide and a black precipitate is formed. |
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