Description

Mac Conkey Agar sorbitol is a selective and differential medium for the isolation and identification of Escherichia coli O157:H7 according to UNI EN ISO 16654:2003 standard.

The medium, using sorbitol instead of lactose as fermentable carbohydrate, isolates and differentiates E. coli's enteropathogenic serotypes, which tend to be negative sorbitol. Sorbitol therefore allows to identify Escherichia coli O157:H7 from other serotypes within the same species. Only Escherichia coli O157: H7 does not ferment sorbitol, presenting colorless colonies, while the other Escherichia coli's serotypes, fermenting sorbitol, produce pink colonies. Sorbitol-fermenting bacteria produce colonies with various shades of red, due to the increase of the neutral red indicator for the production of mixed acids. Klebsiella ed Enterobacter produce red colonies surrounded by a precipitation halo produced by bile salts. Citrobacter, Providencia, Serratia e Hafnia produce slightly pink colonies.

Must be added to the medium the selective supplement Cefixime tellurite Supplement (Cod. 76.028)

Packing:

• Cod. B70.320 Pack. 5 Kg
• Cod. 70.320 Pack. 500 g
• Cod. 71.320 Pack. 100 g
• Cod. 14.0121V Pack. 20 plates ø 90 mm, ready to use
• Cod. 20.053 Pack. 6 bottles 100 ml

Bibliography:

• ISO 16654:2001 Microbiology of food and animal feeding stuffs -- Horizontal method for the detection of Escherichia coli O157
• UNI EN ISO 16654:2003_Microbiologia di alimenti e mangimi per animali - Metodo orizzontale per la ricerca di Escherichia coli O157