1. Azabu University Mastitis Research Center, Kanagawa, Japan
2. Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
3. Higashi-Hiroshima Veterinary Clinical Center, Hiroshima, Japan
4. School of Veterinary Medicine, Azabu University, Kanagawa, Japan
5. Department of Molecular Life Science, Tokai University School of Medicine, Kanagawa, Japan