Popis: |
Summary A new rapid method 1 for determining microbial surface contamination has been developed. Samples are taken with cotton swabs and transferred directly to agar slants. The slants are grouped according to the number of colonies formed during incubation, and the average number of colonies and its standard deviation are determined by plotting the distribution on probability paper. The method, which is particularly well suited for large scale field examinations, was used to evaluate the efficiency of hydraulic pressure cleaners in a pig slaughterhouse. As a result of the daily use of the pressure cleaners, the bacterial surface contamination on the machinery and equipment was in no place higher than about 100/cm2 after cleaning. Further, there was a 90% reduction of the surface counts on the dressed pig carcases. Also, the cleaning was more rapidly done than by the traditional methods. |