Model of bacteriologic effectiveness testing of disinfectants for veterinary medicine

Proper evaluation of effectiveness of chemical disinfectants depends on availability of a standardised test methodology which can provide reproducible values. The binding rules and regulations for testing and acceptance under the heading of "Methods for Testing Chemical Disinfectants for Veterinary Medicine" (team of authors, 1987) have resulted from years of experimental research in the field of disinfectant development. They include a model for bacteriological laboratory testing which is described in this paper, with complementary reference being made to experimental planning and appraisal of disinfection success. An account is given of preparatory testing, using agar diffusion and serial dilution tests, and of main testing, using suspension and microorganism carrier tests. The RF% microorganism reduction rate is introduced for appraisal of disinfection success. With differentiated initial germ counts, the comparability of experimental results provided by RF% has proved to be superior to that obtainable from conventional calculation.