Evaluation of dry sheet medium culture plate (Compactdry TC) method for determining numbers of bacteria in food samples

The Compactdry, a ready-to-use and self-diffusible dry medium sheet culture system, has been developed by the Nissui Pharmaceutical Co. Ltd. for enume rating bacteria in food. The Compactdry consists of special spread sheet wi th culture medium that is the same as standard method nutrients, a cold wat er-soluble gelling agent, and a unique plastic dish. The procedure for bact erial examination in a sample solution (1 mi) is to just inoculate a test s olution into the center of the self-diffusible medium and incubate at 35 de grees C for 48 h, The Compactdry TC (CTC) for the enumeration of total aero bic bacteria from 97 food samples was compared with the standard plate coun t (SPC) method and 3M Petrifilm aerobic count plates (PAC). The correlation coefficients between the CTC and SPC method, the CTC and PAC, and the PAC and SPC method were 0.97, 0.99, and 0.97, respectively. The Compactdry syst em is useful for the enumeration of total aerobic bacteria in food and may be a possible suitable alternative to the conventional pour-plate or the Pe trifilm plate methods.