1. United States Department of Agriculture, Agricultural Research Service, Aquatic Animal Health Research Laboratories, Auburn, AL, USA
2. United States Department of Agriculture, Agricultural Research Service, Aquatic Animal Health Research Laboratories, Chestertown, MD 21620, USA
3. Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, UT, USA
4. Division of Microbiology, Joshi-Eiyoh University, Chiyoda, Sakado, Saitama 350-0288, Japan