OXOID SORBITOL MacCONKEY AGAR (SMAC) with BCIG CM0981 500 gr

SORBITOL MacCONKEY AGAR (SMAC) with BCIG Code: CM0981 Description SMAC with BCIG combines two different screening mechanisms for the detection of Escherichia coli O157, the failure to ferment sorbitol and the absence of b -glucuronidase activity. In a study with artificially contaminated meat samples, SMAC with BCIG reduced the number of false suspect Escherichia coli O157 colonies by 36%1. The formulation includes 5-bromo-4-chloro-3-indolyl- b-D-glucuronide (BCIG) as a substrate for b-glucuronidase, an enzyme which is not usually present in Escherichia coli O157 strains. The non-sorbitol-fermenting and b-glucuronidase-negative Escherichia coli O157 will appear as straw coloured colonies. Organisms with b-glucuronidase activity will cleave the substrate and release indoxyl (or halogenated indoxyl) which is rapidly oxidised to the insoluble indigo or its analogue, leading to a distinct blue-green colouration of the colonies2.