1. Leptospirosis and Mycobacteriosis Research Unit, National Animal Disease Center, USDA, Agriculture Research Service, PO Box 70, Ames, IA 50010
2. Veterinary Research Laboratory, Stormont, Northern Ireland
3. Iowa Veterinary Diagnostic Laboratory, Ames, IA 50010
4. SmithKline-Beecham, Lincoln, NE 68501
5. Animal Disease Diagnostic Laboratory, Purdue University, West Lafayette, IN 47907