28th ANNUAL EASTERN FISH HEALTH WORKSHOP April 21-25, 2003 Use Of Bacterial Flora Databases From Selected Unionids To Identify Disease Causing Agents Clifford Starliper1, Richard Neves2, William Henley2, Shane Hanlon3, Alison Griffin1 And Pamela Whittington1 1National Fish Health Research Laboratory Usgs, 11700 Leetown Road, Kearneysville WV 25430; 2Virginia Cooperative Fish And Wildlife Research Unit USGS, Blacksburg, Va 24061; 3Southwest Virginia Field Office USFWS, Abingdon, VA 24210 Mussel mortality events (i.e. dieoffs) are being noted and most often a cause is not identified; in fact, the cause is not distinguisted between infectious or non-infectious.  With some dieoffs, several associated criteria, such as, gravidity, seasonality and host specificity have been noted and in other animals (e.g. fishes) these criteria can be predisposing factors to diseases. To date, the etiological causes of diseases and mortality in mussels have been minimally addressed and reported. Dieoffs have been observed, for example, in the Holston and Clinch Rivers in Virginia. Clinical signs include weakened abductor muscles resulting in impaired valve closure. Mortality has occurred among species (some gravid) including Lexingtonia dolabelloides, Pleurobema oviforme and Fusconaia ebena. With this study, we want to position ourselves to identify bacterial agents as a cause of dieoffs. Normal bacterial flora databases are being developed through periodic sampling at sites on the aforementioned rivers. This will allow for comparison to the bacteria from diseased mussels. Mussels are being collected quarterly; 10 per species per site. Pallial fluids and tissue homogenates are used to inoculate microbiological media for primary isolation of bacteria. Resulting bacteria are enumerated and characterized. Bacterial counts range from 3×104 to 4×106 colony forming units (cfu) total. Most frequently, motile Aeromonads, nonfermenters and Enterics were isolated. During this study, a dieoff in the Holston River occurred; two bacteria surfaced as suspected etiological agents when compared to expected normal; challenges are being done in an attempt to fulfill Koch’s Postulates. The goal is, as pathogens are identified, they can be screened during health inspections and strategies can be implemented to prevent transmission to populations of captive reared mussels. Return to 28th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page