Verificación de método analítico para la cuantificación de microorganismos en placas con medio deshidratado

Abstract

Traditional methods for quantifying microorganisms are often time-consuming, causing delays in delivering results to laboratories providing food analysis services. This study aims to evaluate a verification protocol for a rapid method for quantifying Staphylococcus aureus in dehydrated plates following the ISO 16140-3:2021 standard. Two stages are established: implementation verification and article verification. The first consists of calculating the reproducibility standard deviation (SIR) by contaminating twelve ham samples and comparing it with the data provided in the method validation study (SR). The second stage occurs when six foods from different categories are contaminated, a process in which the estimated bias (eBias) is determined, allowing the method's performance to be evaluated. An SRI of 0.042 was obtained, while the SR x 2 is 0.044. For the verification of the six foods, the eBias values were 0.26, 0.41, 0.6, 0.08, 0.26, and 0.08, respectively, which are less than 0.5 Log10; therefore, it can be determined that the results of both stages meet the criteria specified by the standard, concluding that the rapid method has been effectively implemented and can be performed on any food. Keywords: Verification, inoculum, Staphylococcus aureus, rapid method, food category.