1. Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry and Fisheries, 1–2–1 Kasumigaseki, Chiyoda-ku, Tokyo 100–8950, Japan
2. Institute for Food and Environmental Sciences, Tokyo Kenbikyo-in Foundation, 5–1 Toyomicho, Chuo-ku, Tokyo 104–0055, Japan
3. National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, 1–15–1 Tokura, Kokubunji, Tokyo 185–8511, Japan