Use of microbiological indicators for assessing hygiene controls for the manufacture of powdered infant formula

Microbiological testing for various indicator microorganisms is used extensively as a means of verifying the effectiveness of efforts to ensure the microbiological quality and safety of a wide variety of foods. However, for each use of an indicator organism the underlying scientific assumptions related to the behavior of the target microorganism, the characteristics of the food matrix, the details of the food manufacturing processes, environment, and distribution system, and the methodological basis for the assay must be evaluated to determine the validity, utility, and efficacy of potential microbiological indicator tests. The recent adoption by the Codex Alimentarius Commission of microbiological criteria for powdered infant formulae and related products provides an excellent example of an evidence-based approach for the establishment of consensus microbiological criteria. The present article reviews these criteria and those of various national governments in relation to emerging principles for the evidence-based establishment of effective indicator organisms.