1. Research Service, VA Medical Center West Los Angeles, Building 304, Room E3-227, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA
2. Anaerobe Reference Laboratory, National Public Health Institute (KTL), Helsinki, Finland
3. Department of Medical Microbiology, University of Turku, Turku, Finland
4. Department of Microbiology, Immunology, and Molecular Genetics, UCLA School of Medicine, Los Angeles, CA, USA
5. Department of Medicine, UCLA School of Medicine, Los Angeles, CA, USA
6. Infectious Diseases Section, VA Medical Center West Los Angeles, Los Angeles, CA 90073, USA