1. Meningitis and Special Pathogens Branch, Division of Bacterial and Mycotic Diseases,1 and
2. Hospital Environment Laboratory Branch, Hospital Infections Program,2 National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333;
3. Unité des Entérobactéries, Institut National de la Recherche Scientifique, Unité 199, Institut Pasteur, 75724 Paris, France3;
4. Microbial Diseases Laboratory, Division of Communicable Disease Control, Department of Health Services, Berkeley, California 94704-10114;
5. Culture Collection, University of Göteborg, Department of Clinical Bacteriology, S-413 46 Göteborg, Sweden5; and
6. Department of Clinical Microbiology, National Institute of Public Health, 100 42 Prague 10, Czech Republic6