1. Department of Oral Biology, Faculty of Dental Medicine,1 and
2. Department of Clinical Microbiology,2 The Hebrew University-Hadassah Medical School, Jerusalem 91120,
3. Dan Fish Farms, Kibbutz Dan, Upper Galilee 12245,3and
4. Department of Medical Microbiology and Parasitology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 306024
5. Department of Poultry and Fish Diseases, The Kimron Veterinary Institute, Bet Dagan 50250,5Israel, and