1. Laboratory of Microbiology, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan
2. Department of Biochemistry, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan
3. Department of Microbiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan