1. Department of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences Hiroshima University Hiroshima Japan
2. Department of Advanced Prosthodontics Hiroshima University Graduate School of Biomedical and Health Sciences Hiroshima Japan
3. Department of Bacteriology Hiroshima University Graduate School of Biomedical and Health Sciences Hiroshima Japan
4. Project Research Center for Nosocomial Infectious Diseases Hiroshima University Hiroshima Japan
5. Antimicrobial Resistance Research Center National Institute of Infectious Diseases Tokyo Japan
6. Department of Infectious Diseases Hiroshima University Hospital Hiroshima Japan