1. From the Clinical Microbiology Laboratory, Department of Pathology (Drs Carlson and Li, and Ms Helton), Center for Comparative Medicine (Mr Munn and Dr Wasson), Department of Surgery (Dr Perez), Department of Internal Medicine (Dr Gallay), University of California, Davis, Medical Center, Sacramento; and Department of Anatomic Pathology, San Francisco General Hospital, San Francisco, Calif (Dr Fin