1. Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
2. Department of Medical Technology, Kansai University of Health Sciences, Kumatori, Osaka, Japan
3. Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
4. Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan