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Sorbitol MacConkey Agar with BCIG (SMAC with BCIG)

[所属分类:培养基配方] [发布时间:2021-8-19] [发布人:网站管理员2] [阅读次数:] [返回]

Sorbitol MacConkey Agar with BCIG

(SMAC with BCIG)

山东拓普生物工程有限公司培养基配方 http://www.topbiol.com

Composition per liter:

Peptone ....................................................................................... 20.0g

Agar ............................................................................................ 15.0g

Sorbitol ....................................................................................... 10.0g

NaCl.............................................................................................. 5.0g

Proteose peptone........................................................................... 3.0g

Bile salts mixture .......................................................................... 1.5g

5-Bromo-4-chloro-3-indolyl-β-D-glucuronide sodium salt .......... 0.1g

Neutral Red................................................................................. 0.03g

pH 7.1 ± 0.2 at 25°C

Source: This medium is available from Oxoid Unipath.

Preparation of Medium: Add components to distilled/deionized

water and bring volume to 1.0L. Mix thoroughly. Gently heat while

stirring and bring to boiling. Autoclave for 15 min at 15 psi pressure–

121°C. Pour into sterile Petri dishes.

Use: A selective and differential medium for the detection of

Escherichia coli O157 incorporating the chromogen 5-bromo-4-

chloro-3-indolyl-β-D-glucuronide (BCIG). The medium combines two

different screening mechanisms for the detection of E. coli O157, the

failure to ferment sorbitol and the absence of β-glucuronidase activity.

The non-sorbitol-fermenting and β-glucuronidase-negative E. coli

O157 will appear as straw-colored colonies. Organisms with β-

glucuronidase activity will cleave the substrate, leading to a distinct

blue-green coloration of the colonies. The intestinal tract of ruminants

is the prime reservoir of E. coli O157 and other enterohemorrhagic E.

coli (EHEC) strains; therefore meats derived from cattle, sheep, goat,

and deer can be expected to be contaminated. Foods implicated in

human illness related to E. coli O157 include meats, dairy products,

vegetables, salads, apple juice, and water.