InMicro® Dehydrated: EE Broth (Buffered Glucose Brilliant Green Bile Broth)

Enrich Enterobacteriaceae in the bacteriological examination of foods and animal feed stuffs with InMicro® Dehydrated: EE Broth (Buffered Glucose Brilliant Green Bile Broth). This medium is more inhibitory to non-Enterobacteriaceae than other non-selective media, e.g. Mannitol broth or Lactose broth by virtue of the presence of brilliant green and bile salts in the preparation.

To monitor the sanitary quality of food and drugs, it is important to enumerate Enterobacteriaceae in samples accurately. E.E. Broth is recommended as an enrichment medium for Enterobacteriaceae in the bacteriological examination of foods and animal feedstuffs.

• Selective: non-Enterobacteriaceae are inhibited due to brilliant green and bile salts in the medium
• Reliable: overcomes inhibition of small numbers of Enterobacteriaceae cells due to bile salt variations
• Accurate: the entire Enterobacteriaceae group can be used as indicator organisms avoiding discrepancies which can occur with standard `coli-aerogenes’ test

The medium is more inhibitory to non-Enterobacteriaceae than other non-selective media (e.g., Mannitol broth or Lactose broth) due to the presence of brilliant green and bile salts.

The reliability of methods used to enumerate Enterobacteriaceae depends on resuscitation of damaged cells. Weakened cells arise from exposure to dehydration, low pH and other unfavorable conditions. E.E. Broth’s formulation includes purified ox bile to overcome the inhibition of small numbers of Enterobacteriaceae cells due to bile salt variations. A preliminary assay can be used to check growth by inoculating approximately one viable cell per medium unit.

For the bacteriological evaluation of processed foods, the entire Enterobacteriaceae group can be used as indicator organisms. This overcomes discrepancies that can arise when lactose-negative, anaerogenic lactose-positive or late lactose fermenting enterobacteria are present but are missed by the standard `coli-aerogenes’ tests.

To overcome these problems, lactose media have been replaced by those containing glucose. Mossel et al cited several examples which referred to foods contaminated with salmonellae, although results for coliforms were negative. A later example quoted by Mossel involved an outbreak of diarrhea caused by French mold-fermented soft cheese contaminated by Escherichia coli serotype O124. This organism was lactose-negative and, therefore, was not detected in coliform tests, but only recognized when the commodity was tested for Enterobacteriaceae since it fermented glucose rapidly.

 E.E. Broth should be used as an enrichment broth in conjunction with InMicro® Dehydrated: Violet Red Bile Glucose Agar. When specific organisms are required, rather than Enterobacteriaceae in general, subcultures must be made onto lactose differential media, e.g., Desoxycholate Citrate Agar.