[Quantitative Survey of Campylobacter on Chicken Livers in Japan]

Chicken liver is a potential source of campylobacteriosis in humans. Therefore, we determined the number of Campylobacter in chicken liver. In total, 33 vacuum-packed liver products were obtained from retail stores, and found that 27 of the 33 products (81.8%) were contaminated with Campylobacter. Moreover, Campylobacter was isolated from 138 of 149 livers (92.6%) collected from the 27 Campylobacter-positive products. The mean Campylobacter count was 2.3 log₁₀ CFU/g, while Campylobacter count in 22 of the 138 contaminated livers (15.9%) was >3.0 log₁₀ CFU/g. Furthermore, gastrointestinal tract, liver, and bile samples were collected from 35 broilers at chicken processing plants. We isolated Campylobacter from the gastrointestinal tract of 27 broilers (77.1%). Of these 27 broilers, liver of 24 broilers (88.9%) was Campylobacter-positive, with a mean Campylobacter count of 2.8 log₁₀ CFU/g. Of these 24 broilers, bile of 13 broilers (54.2%) was contaminated with Campylobacter (mean Campylobacter count, 3.5 log₁₀ CFU/mL). Among them, bile of 2 broilers had a Campylobacter count of >8.3 log₁₀ CFU/mL. Collectively, these results indicate that livers derived from broilers colonized with Campylobacter are contaminated with Campylobacter at the time of evisceration. Therefore, to prevent foodborne campylobacteriosis in humans, chicken livers should be thoroughly heated before consumption.