Commission Decision of 20 December 2007 concerning a financial contribution from the Community towards a survey on the prevalence of Salmonella spp. and Methicillin-resistant Staphylococcus aureus in herds of breeding pigs to be carried out in the Member States (notified under document number C(2007) 6579) (2008/55/EC)

2. Laboratory analytical methods U.K.

2.1. Laboratories U.K.

Analysis and serotyping shall take place at the National Reference Laboratory (NRL). Where the NRL does not have the capacity to perform all analyses or if it is not the laboratory that performs detection routinely, the competent authorities may decide to designate a limited number of other laboratories involved in official control of Salmonella to perform the analyses. These laboratories shall have proven experience of using the required detection method and have a quality assurance system complying with ISO 17025 and be submitted to the supervision of the NRL.

2.2. Receipt of samples U.K.

At the laboratory, samples shall be kept refrigerated until bacteriological examination, which shall preferably be carried out within 24 hours after receipt but in any case no later than 96 hours after the sample was collected.

2.3. Sample analysis U.K.

Member States shall guarantee that all involved parties have been sufficiently trained to carry out the analyses.

2.3.1. Preparation U.K.

In the laboratory, routine samples shall be mixed carefully and thoroughly, before 25 g is collected for analysis.

For evaluation of the within-holding prevalence in accordance with paragraph 1.2, each of the individual collected samples (30 g) needs to be divided into two parts. One part, weighing at least 25 g shall be mixed carefully and thoroughly and subsequently cultured individually. The remaining second part is to be used to prepare an artificially pooled sample from the 10 individual samples in the selected pen, group or yard. This latter part shall be prepared by adding 10 times 2,5 g of the individual samples to create an artificially pooled sample of 25 g. The artificially pooled samples are mixed carefully and thoroughly before analysis. In total, 10 routine samples, 10 artificially pooled sample and 100 individual samples shall be analysed from each of the 10 holdings selected for the estimation of the within-holding prevalence.

2.3.2. Detection and identification methods U.K.

2.3.2.1. Detection of Salmonella U.K.

The method recommended by the Community Reference Laboratory (CRL) for Salmonella in Bilthoven, the Netherlands, shall be used. This method is described in the Annex D of ISO 6579: ‘Detection of Salmonella spp. in animal faeces and in samples of the primary production stage’. The latest version of Annex D shall be used.

2.3.2.2. Serotyping of Salmonella U.K.

All strains isolated and confirmed as Salmonella spp. shall be serotyped according to the Kaufmann-White scheme, by the NRL for Salmonella.

For quality assurance, 16 typable strains and 16 non-typable isolates shall be sent to the CRL for Salmonella. A proportion of these isolates shall be sent to the CRL on a quarterly basis. If fewer strains have been isolated, all shall be sent.

2.3.2.3. Phage typing of Salmonella U.K.

In case isolates of Salmonella Enteritidis and Salmonella Typhimurium are phage typed (optional), the methods described by the WHO reference centre for phage typing of Salmonella of the Health Protection Agency (HPA) Colindale, London, shall be used.