Comparison between selective media for Escherichia coli and coliforms simultaneous determination in food of animal origin

The performance of three new coltural media called Coli ID (Bio Merieux), Chromocult Coliform Agar (Merck) e Colicrom Agar (DID), which base their specific power in the beta-glucuronidase and beta-galactosidase enzymatic reactions and allow the Escherichia coli and coliforms determination at the same time, has been evaluated in comparison to Rapid' E. coli and V.R.B.A., respectively used for the research of the above mentioned micro-organisms. The comparative study showed that Coli ID is more selective and specific than the other new media and than V.R.B.A. Regarding Escherichia coli determination, Coli ID demonstrated to be as specific as Rapid' E. coli but able to give much higher counts.