A Plating Medium for the Isolation and Enumeration of Enterococci

Abstract

Summary A selective plating medium for the isolation and identification of the enterococcus group of streptococci has been developed. The method is based upon the ability of the enterococci to utilize sodium citrate as an available carbon source, to convert ditetrazolium chloride to a blue diformazan and to grow in the presence of 0.01 per cent sodium azide. Results are presented which show that the selective plating medium can be used to isolate and estimate the numbers of enterococci in raw milk.