Survival of Campylobacter coli in porcine liver

Enteropathogenic Campylobacter jejuni, Campylobacter coli and Campylobacter lari are currently the most common causes of acute infectious diarrhoeal illness in the UK and in most developed countries. Many domestic animals, including pigs, act as natural reservoirs of these organisms and infection may occur through the ingestion of contaminated foodstuffs. Therefore, the safety of porcine liver produced in Northern Ireland was assessed in relation to Campylobacter spp. Storage trials showed that Campylobacter spp. were not able to proliferate in liver at 37 degrees C, but could persist at 4 degrees C and 15 degrees C. Survival was better, however, during storage at 4 degrees C than at 15 degrees C. Campylobacter were rapidly killed in raw liver homogenates and distilled water at 37 degrees C, but not at 4 degrees C. An initial inoculum of 8 log10 cfu g-1 C. coli was undetectable in liver homogenates after 24 h storage at 37 degrees C. Campylobacter coli were sensitive to freezing on liver slices at -18 degrees C and were reduced by 5 log10 cycles after 7 days storage. Cells survived better on chilled liver slices and in autoclaved liver homogenates than in raw liver homogenates at all temperatures, which indicates the presence of a heat-labile antagonistic agent in raw liver homogenates. Growth and survival of C. coli was not affected by Lactobacillus plantarum, as C. coli was able to reach 8.5 log10 cfu ml-1 in 7 days and maintain its viability in the presence of 8.0 log10 cfu ml-1 L. plantarum. Thus, storage of C. coli on porcine liver at 4 degrees C selected for the survival of this pathogen compared to similar storage at 37 degrees C. Such information may be useful in identifying conditions and treatments that could be integrated in HACCP strategies, or be used to design processes that prevent proliferation and/or destroy Campylobacter spp. that may be present in liver.