1. Department of Host Defense, Graduate School of Medicine University of the Ryukyus Okinawa Japan
2. Department of Environmental Medicine and Molecular Toxicology Tohoku University Graduate School of Medicine Sendai Japan
3. Molecular Microbiology Group, Tropical Biosphere Research Center University of the Ryukyus Okinawa Japan
4. Advanced Medical Research Center, Faculty of Medicine University of the Ryukyus Okinawa Japan
5. Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Okayama Japan
6. Department of Bacteriology Niigata University School of Medicine Niigata Japan