Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2008
Publication Date: 4/16/2008
Citation: Ozbay,G.,Kingsley,D.2008 Persistance of Viruses in Oyster (Crassostrea Virginica)Hemocytes.Join 1890 AEA/ARD Land Grant Conference.Memphis,TN. p.1.
Technical Abstract: Seafood is listed as one of the top three causes of human virus infection by foodborne products. The goal of this study is to determine why human enteric viruses such as hepatitis A (HAV) and Norovirus (NV) readily persist within bivalves. Shellfish bioaccumulate water-borne pathogens and concentrate virus particles suspended in the water column. Unlike fecal bacteria, gastrointestinal viruses can not be efficiently removed by depuration (placing live shellfish in clean water for up to 72 hours). Our current hypothesis is that these viruses persist within phagocytic hemocytes, cells that have both digestive and immunological functions. The presence of HAV within hemocytes after oyster exposure to HAV-contaminated water has been demonstrated by RT-PCR. Hemocytes removed from oysters test positive for up to 20 days following a single overnight exposure to HAV-contaminated water. Currently three separate approaches are being followed to evaluate the persistence of viruses within shellfish. 1) Adoptive transfer of HAV-contaminated hemocytes from HAV-exposed oysters to naïve, unexposed oysters will be evaluated. 2) Silica is being evaluated as a functional blocker of phagocytosis and hemocyte function. Preliminary data on the survivability of oysters injected with silica indicates that it can be used a function blocker of the phagocytic activity. 3) Fluorescence-activated cell sorting will be employed to determine which hemocyte subgroup or groups(s) take up these enteric viruses. The information obtained will make a significant contribution towards the existing body of knowledge on shellfish physiology, immunology, and virology. Collectively, the basic research gained here should aid in the development of practical measures useful in reducing the uptake and/or retention of human pathogenic viruses by edible shellfish.