M E S '9 8 - University of Georgia College of Veterinary Medicine

WildlifeGeorgia’s wildlife habitat is continually changing as more people and domesticanimals move into the countryside. This change brings concerns about diseaseinteraction among wildlife, domestic animals, and humans. In addition, hunting,a popular form of wildlife recreation, adds hundreds of millions of dollars toGeorgia’s economy, and as such, depends on the health of the state’s wildlife.VMES researchers are studying many wild species, including white-tailed deer,wild turkeys, wild swine, foxes, raccoons, skunks, small rodents, and songbirds,to learn more about each animal’s role in disease maintenance and transmission.Recent research projects have involved diseases such as rabies, Escherichia coliO157:H7, leptospirosis, ehrlichiosis, Lyme disease, pseudorabies, swinebrucellosis, sarcoptic mange, and mycoplasmosis. Although research objectivesvary by project, the main goals are to determine the importance of each diseaseto the health of wildlife, domestic animals, and people, and to devise ways tominimize that disease’s undesirable impact. At times, researchers have identifiedwildlife as a key part of a specific disease problem, but there also are numerousinstances in which studies clearly demonstrate that wildlife is not involved.Either way, research provides the understanding that is required before rationalsolutions are possible to maintain a healthy environment for Georgia’s peopleand animals.P-selectin Regulation in EpizooticHemorrhagic Disease Virus InfectionThe epizootic hemorrhagic disease viruses,along with the closely related bluetongueviruses, cause a devastating disease in whitetaileddeer commonly known as hemorrhagicdisease. These viruses occasionally cause diseasein cattle, and the bluetongue viruses causesignificant morbidity and mortality in sheep.Although it is known that these viruses infectand kill the cells that line blood vessels resultingin severe hemorrhage, infection of thesecells no doubt triggers other events that eitherpotentiate or ameliorate the disease. P- and E-selectin are proteins that are expressed on thesurface of the cells lining the blood vesselswhen these cells are activated by a variety ofinsults. When expressed, these proteins directthe migration of cells involved in cellularimmunity, inflammation, or hemostasis to sitesof vascular injury. Little is known, however,about the expression or role of selectins duringviral infections. We have found that both P andE selectin are expressed on the cells lining theblood vessels during epizootic virus infection,both in vitro and in vivo. Expression was higherin cattle, which rarely develop disease followinginfection, than in the extremely susceptiblewhite-tailed deer. This low-level ofselectin expression in white-tailed deer followinginfection with epizootic hemorrhagic diseasevirus may partially explain the extremesusceptibility of deer to these viruses.Elizabeth W. Howerth and David E. Stallknechtehowerth@calc.vet.uga.eduVeterinary student Debbie Perzak, a participantin the Merck Summer Scholar ResearchProgram, working on vesicular stomatis virus.Survey of Wild White-tailed Deer inGeorgia for Escherichia coli O157:H7Cattle are a source of the human foodbornepathogen Escherichia coli O157:H7.Deer also are suspected as a source because ofrecent isolations of the bacteria from deerfeces and confirmation of venison as thesource of two small clusters of human disease19