1. Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
2. Department of Antimicrobial Resistance, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
3. Hiroshima University Project Research Center for Nosocomial Infectious Diseases, Hiroshima, Japan
4. Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
5. Department of Oral Surgery, Hiroshima Red Cross and Atomic-bomb Survivors Hospital, Hiroshima, Japan
6. Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan