1. Department of Bacteriology, Juntendo University, Tokyo, Japan
2. Department of Microbiology and Infectious Diseases, Women's and Children's Hospital, North Adelaide
3. Molecular Genetics Research Unit, School of Biomedical Sciences, Curtin University of Technology
4. Department of Microbiology and Infectious Diseases, Royal Perth Hospital, Perth, Australia
5. National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333