Mika Haruna

Campylobacter Cross‐Contamination of Chicken Products at an Abattoir

Consumption of raw or undercooked poultry products contaminated with Campylobacter has been identified as a risk factor for human campylobacteriosis. We determined whether slaughtering of Campylobacter‐positive flocks was associated with contamination of chicken products derived from Campylobacter‐negative flocks slaughtered at the same abattoir. The presence of Campylobacter was investigated in 22 broiler farms 1 week prior to slaughter and in one abattoir on nine separate slaughter days. A total of 600 bulk packed chicken products were tested, with 198 (33.0%) of the products found to be Campylobacter positive. Of the 350 chicken products originating from Campylobacter‐positive flocks, 180 (51.1%) were contaminated with the bacteria. In contrast, only 18 (7.2%) of 250 chicken products derived from Campylobacter‐negative flocks were contaminated. In 14 of these 18 products, the Campylobacter isolates were identical to isolates obtained from the flock slaughtered immediately prior to the Campylobacter‐negative flock. Notably, on 4/6 slaughter days, Campylobacter‐negative flocks were slaughtered prior to the positive flocks, and Campylobacter was absent from all chicken products originating from the negative flocks. These results suggest that implementation of logistic slaughter (where Campylobacter‐negative flocks are slaughter first) significantly decreases the prevalence of Campylobacter‐positive chicken products.

Prevalence and Antimicrobial Susceptibility of Foodborne Bacteria in Wild Boars (Sus scrofa) and Wild Deer (Cervus nippon) in Japan

This study aimed to evaluate the role of wild boars and deer as reservoirs of foodborne bacteria. We investigated the prevalence and antimicrobial susceptibility of Campylobacter spp., Salmonella spp., Shiga toxin-producing Escherichia coli (STEC) O157 and O26, and Listeria monocytogenes isolated from wild boars and deer in Japan, from July through December 2010. Campylobacter spp. and Salmonella spp. were isolated from 43.8% (95% confidence interval [CI]: 35.0-52.6) and 7.4% (95% CI: 2.8-12.1) of rectal content samples of wild boars, respectively, but not from wild deer. The most common Campylobacter species was C. lanienae and C. hyointestinalis. The nine Salmonella serovars isolated were S. enterica subsp. enterica serovar Agona (three isolates), S. Narashino (two), S. Enteritidis (one), S. Havana (one), S. Infantis (one), and S. Thompson (one). Five (16%) and 6 (29%) isolates of C. lanienae and C. hyointestinalis, respectively, were resistant to enrofloxacin. STEC O157 and O26 and L. monocytogenes were isolated from 2.3% (95% CI: 0-5.0), 0.8% (95% CI: 0-2.3), and 6.1% (95% CI: 1.7-10.5) of the rectal content samples of wild deer, respectively, but not from wild boars. This first nationwide survey of the prevalence of foodborne bacteria in wild boars and wild deer in Japan suggests that consumption of meat from these animals is associated with the risk of causing infection with these bacteria in humans. Moreover, these animals are potential vehicles for distribution of antimicrobial-resistant bacteria into their habitat. The prevalence and antimicrobial susceptibility of such foodborne bacteria in these wild animals should be monitored periodically.

Contamination of Poultry Products with Listeria monocytogenes at Poultry Processing Plants

ABSTRACT This study aimed to confirm that poultry products packed at poultry processing plants have already been contaminated with Listeria monocytogenes and that poultry products contaminated with L. monocytogenes are derived from broiler flocks infected with L. monocytogenes. L. monocytogenes was isolated from 16.8% (58/345) of chicken breast products and 2.3% (8/345) of chicken liver products. In contrast, L. monocytogenes was isolated from the pooled cecal content sample from only 1 (4%) of 25 flocks and was never isolated from any pooled dropping samples collected from 25 farms. The results of our study indicate that cecal content does not seem to be an important source of L. monocytogenes in poultry products.

Prevalence and phylogenetic analysis of hepatitis E virus in pigs in Japan

The number of reported cases of human hepatitis E virus (HEV) infection has increased since 2012. Pigs are considered an important source of viruses causing human HEV infection. It is possible that the prevalence of HEV among pigs at slaughter age (approximately 6 months old) has increased in the last decade. Therefore, we investigated the current prevalence of HEV among pigs in Japan. Although HEV RNA was detected in rectal content samples from pigs aged from one to 5 months, no HEV RNA was detected in any samples from 6-month-old pigs. The highest viral shedding prevalence (33%) was detected among 3-month-old pigs. This study shows that there has been no change in the prevalence of HEV among pigs at the slaughter age, in the prevalence of HEV by age group on pig farms, or in the phylogenetic classification of HEV isolates in the last decade. Therefore, factors downstream of the pork production stage may be contributing to the increased number of human HEV infection cases.