1. US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, HI 96850, USA
2. University of Hawaii, Pacific Biosciences Research Center, Biological Electron Microscope Facility, Honolulu, HI 96822, USA
3. Cornell University, Department of Microbiology, Ithaca, NY 14853, USA
4. University of North Carolina, Wilmington, NC 28403, USA