Document Type



Virginia Institute of Marine Science

Publication Date



During 1997-99, the Aquatic Animal Disease Diagnostic Laboratory (AADDL) at the Virginia Institute of Marine Science (VIMS) investigated and documented an epizootic of disease in wild striped bass, Morone saxatilis, from many portions of the lower Chesapeake Bay. Some of these fish exhibited an ulcerative dermatitis initially suspected of being caused by Pfiesteria piscicida, a dinoflagellate. Skin ulcers ranged from pinpoint, pigmented spots to large, shallow hemorrhagic (bloody) wounds. This disease was determined to be due not to Pfiesteria, but to a group of bacteria called Mycobacterium spp. This disease syndrome is referred to as mycobacteriosis. Further investigations by VIMS researchers and collaborators at the Centers for Disease Control (CDC) identified a new species, M. shottsii, as the most frequently isolated mycobacteria from striped bass during this epizootic (Rhodes et al., 2001c; Rhodes et al., 2002). During 2001-2002, the Virginia Saltwater Recreational Fishing Development Board funded a proposal to compare rates of detection of this disease by three methods, histology, quantitative bacteriology, and the molecular technique of polymerase chain reaction (PCR) and nested PCR. This report summarizes the results of our yearlong investigation of this disease.



Striped bass -- Diseases -- Chesapeake Bay (Md. and Va.), Mycobacteria