1. Clinical Microbiology Laboratories, Sacramento Medical Center, California
2. Antimicrobic Testing Laboratory, Center for Disease Control, Atlanta, Georgia
3. Clinical Microbiology Division, Kaiser Foundation Hospital Laboratories and Department of Pathology St. Vincent Hospital and Medical Center, Portland, Oregon
4. Department of Microbiology, The Cleveland Clinic Foundation, Cleveland, Ohio
5. Microbiology Laboratory, St Francis Hospital, Wichita, Kansas, USA)