Term
| What is included in Moller's Decarboxylase medium? |
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Definition
| peptone, glucose, bromcresol purple, pyridoxal phosphate |
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Term
| What color is bromcresol purple above pH 6.8 and below pH 5.2? |
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Definition
Above pH 6.8: Purple
Below pH 5.2: Yellow |
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Term
| What is used to seal the medium in decarboxylation test after inoculation? |
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Definition
| Mineral oil is used as an overlay to seal from external oxygen and promote fermentation |
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Term
| How is the decarboxylase test used? |
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Definition
| Used to differentiate organisms in the family Enterobacteriaceae and distinguish them from other gram-negative rods. |
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Term
In the decarboxylation test explain the following results:
1. No color change
2. Yellow color
3. Purple color |
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Definition
1. No decarboxylation
2. Fermentation; no decarboxylation
3. Decarboxylation; organism produces the specific decarboxylase enzyme |
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Term
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Definition
| A protein derived from collagen, a component of connective tissue |
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Term
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Definition
| Family of extracellular enzymes produces and secreted by some microorganisms to hydrolyze gelatin |
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Term
| How can the presence of gelatinases be detected? |
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Definition
| By using nutrient gelating, a simple test medium composed of gelatin, peptone, and beef extract |
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Term
| At what temperature must nutrient gelatin be incubated at? |
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Definition
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Term
Explain the following results of gelatin hydrolysis test:
1. Gelatin is liquid
2. Gelatin is solid |
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Definition
1. Gelatinase is present
2. No gelatinase is present |
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Term
| What are some gelatinase positive organisms? |
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Definition
| S. aureus, Serratia, Proteus, B. anthracis, B. cereus, Clostridium tetrani, C. perfringens |
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Term
| What does DNase test agar contain? |
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Definition
| An emulsion of DNA, peptides as nutrient source, and methyl green dye |
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Term
| In the DNase test, what will bacterial colonies that secrete Dnase do in the medium? |
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Definition
| Hydrolyze DNA into smaller fragments unbound from the methyl green dye, resulting in a clearing around the growth. |
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Term
| What is the application of the DNase test? |
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Definition
To distinguish Serratia species from Enterobacter
Moraxella catarrhalis from Neisseria species
Staph aureus from other Staph species |
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Term
Explain the following results of Dnase test:
1. Clearing in agar around growth
2. No clearing in agar around growth |
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Definition
1. DNAse is present
2. DNAse is not present |
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Term
| What is SIM medium used for? |
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Definition
Determination of:
1. Sulfur reduction
2. Indole production from tryptophan
3. Motility |
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Term
| What is included in the SIM medium? |
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Definition
| Casein, animal tissue, iron-containing compound, and sodium thiosulfate(form of sulfur) |
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Term
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Definition
| Catalyzes the putrefaction of cysteine to pyruvate |
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Term
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Definition
| Catalyzes the reduction of sulfur at the end of the anaerobic respiratory ETC |
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Term
| In the SIM medium, what does blackening of the medium indicate? |
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Definition
| The production of H2S gas and reduction of sulfur |
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Term
| In the SIM medium, what makes indole production possible? |
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Definition
| The presence of tryptophan |
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Term
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Definition
| Enzyme that can hydrolyze tryptophan to pyruvate, ammonia, and indole |
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Term
| How can the hydrolysis of tryptophan be detected in the SIM medium test? |
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Definition
| By the addition of Kovacs' reagent after a period of incubation. A positive result is formation of a red color |
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Term
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Definition
| Contains dimethylaminobenzaldehyde(DMABA) and HCl dissolved in amyl alcohol. DMBA reacts with any indole and turns the reagent layer red. |
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Term
| In SIM medium, how is motility detected? |
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Definition
| Because it is stabbed with a needle, motile organisms will move around in the semisolid medium and produce radiating growth pattern extending outward in all directions from the central stab line. |
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Term
Explain the following results in the SIM medium:
1. Red in the alcohol layer of Kovacs' reagent
2. Reagent color is unchanged |
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Definition
1. Tryptophan is broken down into indole and pyruvate
2. Tryptophan is not broken down into indole and pyruvate |
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Term
Explain the following results in the SIM medium:
1. Black in the medium
2. No black in the medium |
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Definition
1. Sulfur reduction (H2S production)
2. Sulfur is not reduced |
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Term
Explain the following results in the SIM medium:
1. Growth radiating outward from stab line, looks fuzzy
2. No radiating growth |
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Definition
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