Search

White tailed deer (Odocoileus virginianus) were inoculated with foot-and-mouth disease virus (FMDV) O UKG 11/2001 and monitored for the development of clinical signs, histopathological changes and levels of virus replication. All FMDV-infected deer developed clinical signs starting at 2 days post inoculation and characterized by an increase in body temperature, increased salivation and lesions in the mouth and on the feet. Virus spread to various tissues was determined by quantifying the amount of FMDV RNA using quantitative reverse transcriptase polymerase chain reaction. Virus or viral antigen was also detected in tissues using traditional isolation techniques, enzyme linked immunosorbent assay and immunohistochemistry. Deer-to-cattle transmission of the virus was observed in this experimental setting; however, inoculated deer were not found to become carriers of FMDV., (Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.)

Current understanding of capripoxvirus pathogenesis is limited since there have been no detailed studies examining cell tropism at well-defined intervals following infection. We undertook time-course studies in sheep and goats following inoculation of sheeppox or goatpox viruses in their respective homologous hosts, and examined tissues by light microscopy. A monoclonal antibody generated to a sheeppox virus core protein was used for immunohistochemical detection of viral antigen in tissue sections. Lesions and virus antigen were observed consistently in the skin, lung and lymph nodes. Antigen was detected at 6 and 8 days post inoculation for skin and lung, respectively, within cells which appeared to be of monocyte/macrophage lineage. In sheep skin capripoxvirus immunoreactivity was detected within previously unreported large multinucleated cells. In the lung, double immunolabelling detected the simultaneous expression of capripoxvirus antigen and cytokeratin indicating the presence of virus within pneumocytes. Lung double immunolabelling also detected the expression of capripoxvirus antigen in CD68(+) cells, confirming the presence of viral antigen within macrophages. Based on early detection of infected macrophages, dissemination of virus within the host and localization to tissues likely occurred through cells of the monocyte/macrophage lineage. Histological findings revealed similarities with both monkeypox and smallpox, thus capripoxvirus infection in sheep and goats may represent useful models with which to study strategies for poxvirus-specific virus vaccine concepts and therapeutics., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

Considerable advances in understanding of the disease caused by Burkholderia mallei have been made employing a combination of tools including genetic techniques and animal infection models. The development of small animal models has allowed us to assess the role of a number of putative virulence determinants in the pathogenesis of disease due to B. mallei. Due to the difficulties in performing active immunization studies in small animals, and due to the fact that the horse is the target mammalian species for glanders, we have initiated experimental studies on glanders in horses. Intratracheal deposition of B. mallei produced clinical glanders with organisms being recovered from tissues of infected horses. The model should prove to be of considerable value in our ongoing studies on the pathogenesis and vaccine development for glanders.