P14 | Official control at the poultry slaughterhouse: sampling as verification of Salmonella and Campylobacter self-control

L. Torricella, G. Di Serafino, R. Piccioni | Servizio Veterinario di igiene della produzione, trasformazione, commercializzazione, conservazione e trasporto degli alimenti di origine animale e loro derivati, Asl 4 Teramo, Italy

Purpose. Compare the results obtained by the CU according to Regulation (EU) 627/2019 with those derived from the company's own checks provided for in Regulation (EC) 2073/2005 for the search for Campylobacter spp. and Salmonella spp. on broiler carcasses (Table 1). Methods. Methodological differences between CU and self-control (CIP) were analyzed to assess discrepancies in the results. Two tests were considered for each microorganism: -One for qualitative research; -One for typing (only for Salmonella) or for quantification (for Campylobacter). Self-control analyzes were carried out at the accredited laboratory located within the same facility: • For Salmonella spp.: the agent is searched according to standard ISO 6579-1, while for typing, the AFNOR BRD 07/06-07/04 method is used. • For Campylobacter spp.: the test method PO 35 rev. 7:2023 is used, which involves real-time PCR for identification, followed by plate counting in case of a positive result. Official control is carried out according to the methods: • For Salmonella spp.: ISO/TR 6579-3:2014 for typing. • For Campylobacter spp.: ISO 10272, without using PCR, but with plate counting only. Results. - Campylobacter spp.: the self-monitoring results show a higher frequency of positivity compared to the official samples; - Salmonella spp.: Out of 31 lots negative in the official control, 21 tested positive according to the PNCS, with significant discrepancies. Samples taken for official control are not comparable to those from self-monitoring, as the sampling itself was carried out on different batches/days. The higher frequency of positive samples for Campylobacter detected thru self-monitoring could be linked to the diversity of analytical methods used, or to the presence of an in-house laboratory at the slaughterhouse, which would allow for faster analysis, avoiding the inconveniences associated with sample transport. The 21 batches of chickens that tested negative for PNCS but were subsequently positive for Salmonella spp. in official control can be explained by considering that the PNCS allows sampling up to 20 days before slaughter, a wide time interval that does not exclude subsequent positivity. Additionally, the samples collected for the PNCS may not be representative of the entire group. A less likely but possible explanation is the presence of cross-contamination during the processing stages. The opposite case is also noteworthy: A lot that tested positive for PNCS but was found negative upon official control. This could indicate a positive effect of post-slaughter chilling or the effectiveness of GMPs in reducing contamination. Conclusions. An integrated approach between the competent authority and the food business operator, with better coordination of sampling, would allow for a more objective assessment of the effectiveness of the self-control system and the epidemiological monitoring of Salmonella spp. and Campylobacter spp. The collected evidence also highlights the importance of combining compliance with microbiological criteria with the intensification of biosecurity measures on farms, along with GMP and HACCP programs during slaughter. This strategy can help reduce the colonization of broiler chickens by Campylobacter spp. and Salmonella spp., limiting carcasss contamination from infected flocks.