1. Center for Veterinary Medicine, United States Food and Drug Administration , Laurel, Maryland, USA
2. Washington Department of Fish and Wildlife , Seattle, Washington, USA
3. Center for Food Safety and Applied Nutrition, United States Food and Drug Administration , College Park, Maryland, USA
4. Center for Environmental Measurement and Modeling, United States Environmental Protection Agency , Cincinnati, Ohio, USA
5. Environmental Microbial & Food Safety Lab, United States Department of Agriculture , Beltsville, Maryland, USA