ARS | Publication request: INITIAL EVALUATION OF THE PATHOGENESIS OF NOVEL TURKEY-ORIGIN REOVIRUSES

Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: February 24, 2005
Publication Date: June 8, 2005
Citation: Day, J.M., Pantin Jackwood, M.J., Spackman, E. 2005. Initial evaluation of the pathogenesis of novel turkey-origin reoviruses. In: American Society for Microbiology, June 8, 2005, Atlanta, Georgia. p.23.

Technical Abstract: The avian reoviruses are an important group of poultry pathogens belonging to the genus Orthoreovirus in the family Reoviridae. This study examined the pathogenicity of a novel group of reoviruses originally isolated from commercially raised turkeys experiencing poult enteritis complex (PEC), a polymicrobial disease of unknown etiology characterized by diarrhea and decreased weight gain. These turkey-origin reoviruses (TRV's) were inoculated intra-orally and intra-trachealy into isolated groups of specific pathogen free (SPF) turkey poults at three days post-hatch. At 2, 5, 7, and 9 days post-inoculation (DPI) all birds were weighed and tissues were obtained for subsequent RT-PCR virus detection and microscopic examination. Each of the five isolates tested generally produced mild clinical signs of reovirus infection, although moderate to severe atrophy of the Bursa of Fabricius was noted in each experimentally infected group. The severe bursal atrophy observed in some treatment groups suggests that individuals infected with certain TRV strains may be immunosuppressed. Each TRV treatment group had significantly decreased mean body weights at 2 DPI when compared to the sham inoculated group. No gross intestinal lesions were observed in any group. Reovirus was detected via real time RT-PCR in intestinal tissue from certain treatment groups at 2, 5, and 7 DPI. The antigenic relatedness of the TRV's included in this study is being determined. Further, efforts are underway to sequence the S1 and S3 genomic segments of selected TRV isolates in order to determine their genetic relatedness.