Presence of Listeria and Salmonella spp. in retail chicken in Northern Ireland

Aims: Retail packs of fresh chicken in Northern Ireland were sampled to determine the frequency with which they were contaminated with Salmonella and Listeria spp. Methods: Packs of chicken were chosen from supermarkets ensuring a diverse range of EU producer codes were sampled. Salmonellas were isolated using BS EN 12824: 1998 methodology, biotyped and serotyped whilst Listeria spp. were isolated based on EN ISO 11290-1: 1996 procedures and identified using a multiplex PCR system utilizing genus and species specific primers. Significance and Impact of the Study: Only three of 205 samples yielded Salmonella spp. indicating that measures undertaken by the poultry industry to control this pathogen have apparently been successful. However, Listeria spp. were present in 38 of 80 samples tested (48%) and 14 (18%) yielded Listeria monocytogenes. Thus Salmonella controls do not markedly affect this pathogen and retail packs of raw chicken must be considered a potential source of L. monocytogenes, and appropriate precautions taken to prevent infection.