Guide on the implementation of the Standard EN ISO 19036:2019 for the estimation of measurement uncertainty associated with the enumeration of Campylobacter, coagulase positive staphylococci and Listeria monocytogenes in the food chain

One of the main purposes of the European Union Reference Laboratories (EURLs) for Campylobacter, Coagulase Positive Staphylococci (CPS) and Listeria monocytogenes (Lm), and the associated networks of National Reference Laboratories (NRLs) is to ensure the reliability of official analyses in their respective scope, in the frame of official controls.

The measurement uncertainty (MU) associated with the analyses performed by EURLs, NRLs and official laboratories is recognised to be an important criterion to assess the reliability of these analyses.

The above-mentioned laboratories should:

(i) estimate MU associated with their analyses for Campylobacter/CPS/Lm enumeration, according to the Standard EN ISO 19036:2019 (see clause 2);

(ii) obtain values which can be considered as acceptable (see clause 3).

This document intends to provide the above-mentioned laboratories with guidance on how to implement the Standard EN ISO 19036:20191 for MU estimation associated with Campylobacter/CPS/Lm enumeration in samples from the food chain. This guide does not cover MU associated to the microbiological analysis of water used in the food chain, since another standard, ISO 292012 , deals with MU for the quantitative analysis of the different types of water (drinkable and natural waters). This document also provides guidance on how to assess the MU values obtained.

The present guide is specifically targeted to the enumeration of Campylobacter, CPS, Lm and the comparison of individual enumeration results to the quantitative limits of microbiological criteria related to these bacteria in the EC Regulation 2073/2005, Annex I: criteria 1.2, 1.3, 2.1.9, 2.2.3, 2.2.4, 2.2.5, 2.2.7, 2.4.1. However, it may also apply to the enumeration of any target bacteria, and to the comparison of an enumeration result to a quantitative limit m/M of any microbiological criterion.

The 2019 version of EN ISO 19036 has been prepared by the WG 2 “Statistics” of ISO/TC 34/SC 9 “Food products – Microbiology”. This Standard replaced the first version, which was a Technical Specification (ISO/TS 19036, 2006, amended in 2009). As any European Standard, EN ISO 19036 has been taken over as a National Standard by each of the CEN Members, including all EU Member States. The harmonised and comprehensive approach described in this standard enables to enlarge MU estimation in the community of food microbiology laboratories across Europe.

This document avoids rephrasing the standard but brings clarifications and details on certain aspects of the standard for a harmonised implementation by the three EURLs, the corresponding NRLs networks and corresponding networks of official laboratories in EU Member States.

This document has been prepared on the basis of the existing EURL Lm guide on this topic (“Guide on measurement uncertainty for the enumeration of Listeria monocytogenes”, V1 – 26/03/2009) and replaces it.

The first version of this guide was prepared by EURL Campylobacter, CPS and Lm, reviewed by the respective networks of NRLs, and approved by the Standing Committee on Plants, Animals, Food and Feed on 3 June 2022.