1. Research Microbiologist, Wadsworth Hospital Center, Veterans Administration, and Research Dentist, University of California at Los Angeles
2. Director, Anaerobic Bacteriology Laboratory, Wadsworth Hospital Center, Veterans Administration
3. Chief, Infectious Disease Section, Medical Service, Wadsworth Hospital Center, Veterans Administration, Los Angeles, California 90073, and Professor of Medicine, Department of Medicine. University of California School of Medicine, Los Angeles, California 90024