Division 2.5.2 Quantification of Campylobacter spp.

The quantitative detection of Campylobacter spp. shall be carried out according to ISO/TS 10272-2:2006 ‘Microbiology of food and animal feeding stuffs — Horizontal method for detection and enumeration of Campylobacter spp. Part 2: Colony-count technique’. Starting with 10 ml initial suspension 0,1 ml of this initial suspension and of further dilutions thereof shall be examined to allow the enumeration of up to 10⁶ cfu/g. In addition, 1 ml of the undiluted initial suspension shall be examined to obtain a limit of enumeration of 10 cfu/g. All plate determinations shall be done in duplicate.

To enable correct comparison and judgement of data (for future risk assessment) the measurement uncertainty (MU) of the quantitative determination method shall be estimated for each laboratory.

To estimate the MU the technical specification ISO/TS 19036:2006 shall be used with the exception that the parallel dilutions from the initial suspension is applied for estimation of the MU.

The MU is derived from the intra-laboratory standard deviation of reproducibility. Data on MU estimation shall be collected from May to September in order to ensure positive samples. A total of 12 positive samples shall be examined in duplicate and parallel dilutions prepared from the 10 ml initial suspension. Raw data on MU estimation shall be reported separately as part of the overall description on the implementation of the survey as set out in Part E.