1. Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
2. Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
3. BioDynamics Research Foundation, Kumamoto 862-0954, Japan
4. Faculty of Pharmaceutical Sciences, Sojo University, Kumamoto 860-0082, Japan