[The occurrence of Bacillus cereus in dairy products (authors transl)]

During one year 1390 samples of pasteurized milk products from five different dairies were examined for content of B. cereus. The examination was done on the day of packaging and after incubation at 17 degrees C for 24 hrs. as well. On examination on the day of packaging 8.1 % were positive. No difference could be demonstrated between low-temperature pasteurized and high-temperature pasteurized products. However, differences were found from one plant to another (2.1 %--14.5 %). After incubation B. cereus were isolated from 17.2 % of low-temperature pasteurized samples and from 22.8 % of high-temperature pasteurized products. The occurrence of B. cereus varied according to season. In July-September the level of contamination was 40 %. It is concluded that during summer months bacteriological examination of dairy products should be supplemented with an examination for B. cereus. This could provide a valuable tool in checking the efficiency of dairy cleaning.