Harlequin™ TBGA Chromogenic Medium Allows Simple Enumeration of E. coli

As E. coli contamination of food continues to make the news, in the UK with suspected illegal clam picking from potentially contaminated beaches, and outbreaks of food poisoning in the US traced to E. coli-tainted shredded Romaine lettuce, the importance of reliable monitoring procedures is once again under the spotlight.

Lab M's range of microbiological culture media includes Harlequin™ TBGA (Tryptone Bile Glucuronide Agar), a specialist chromogenic medium for the simple enumeration of E. coli in conjunction with ISO 16649-1:2001 or other standard methods.

Chromogenic substrate in the medium detects the beta-glucuronidase enzyme that is highly specific to E. coli. Since the chromogenic reaction is concentrated within the bacterial colony, enumeration when large numbers are present or in the company of other organisms is straightforward.

All blue colonies are counted as presumptive E. coli, with confirmation requiring just a simple indole test.