Validación de métodos microbiológicos: Recuento de S. aureus por método rápido

Abstract

Abstract: In the present investigation, the validation of the (Association of Analytical Communities) AOAC 2003.08 method for counting Staphylococcus aureus in cheese is carried out, using the selective and differential culture medium Petrifilm, it was developed at six levels of bacterial concentration, in this way The necessary data were obtained that allowed the calculation of the following validation parameters: precision, limit of quantification, linearity, accuracy and uncertainty. For the determination of the AOAC 2003.08 method, the count on 3M petrifilm plates for S. aureus was used. Using a densitometer, the bacterial population was adjusted to 6 concentration levels. The plates were incubated at 35°C for 24 hours. The statistical results using Excel were as follows: the precision was 0.82, with a typical error of 0.21, the uncertainty <20% at all levels, with a reproducibility of 2.20. The evaluated results are within the limits indicated by the EURACHEM Guide for the validation of a microbiological method, therefore guaranteeing the validity of the results.