AS 4659.3:2015 pdf free.Guide to determining the equivalence of food microbiology test methods Part 3: Confirmation tests.
4.1 Define the equivalence determination
The equivalence determination should be defined in terms of the following:
(a) The target organism’s genus, species, serotype, etc.
(b) The alternate method—precisely defined by reference to a publication, manufacturer’s instructions and any optional procedures employed or deviation from the published method.
(c) The reference method—including the specification of any optional steps.
(d) The steps of the methods that are to be compared.
4.2 Define the conditions of the equivalence determination
The conditions of the equivalence determination should he detined in terms ot the following:
(a) The laboratory where testing is performed.
(b) Controls observed by the laboratory during testing, for example, controls on the environment of the laboratory, prevention of cross contamination, controls on media and reagents, calibration of equipment, etc. where these factors are considered critical to the success of either method.
(c) The staff performing the tests (experience, qualifications, etc.).
(d) The starting and finishing dates of the tests.
(e) The batch numbers of media, reagents, etc. used.
NOTE: This information is defined for the purpose of reporting on the equivalence determination and recording factors which may have some hearing on the results obtained. These factors do not necessarily affect (he veracity of the study.
4.3 Select test organisms
Fifty strains should be selected. These are to include diversity in the strain selected. A minimum of 20 positive isolates and 20 closely related negative isolates should be selected. In addition, a minimum of 10 non-related strains should be tested.
The reference cultures prescribed in the Australia Standard method should be included. The other strains may be selected from the following list (in order of preference):
(a) Strains of the target organism isolated by the laboratory.
(b) Strains of the target organism isolated by reference laboratories or industry sources as representative.
(c) Strains of the target organism held by culture collections.
The identity of the strains chosen should he determined by appropriate means (e.g. biochemical, physiological, serological, molecular) before performing further work. Consultation with a rel’erence laboratory or an expert may he necessary. The source and identity of the strains should be recorded.
NOTE: it is possible, by the selection of test strains, to bias the results of the study. Care should be taken to select representative strains which do not possess characteristics which are likely to lead to biased results being obtained.
4.4 Preparation olinoculuni
The test strain inoculum should be such that at least equivalence in sensitivity to the reference method may be demonstrated. The strains chosen should be prepared as prescribed by the method being studied.AS 4659.3 pdf download.