A PCR-based assay for detection of hematodinium sp. in sediment and water from the Maryland coastal bays

Hematodinium sp. is a parasitic dinoflagellate that infects the blue crab Callinectes sapidus and other crustaceans. Using real-time PCR-based methodology, we can now detect Hematodinium parasites in various crab tissues down to as few as 10 parasites per sampled tissue. This method will enable us to understand infection progress through the parasitic life cycle. One important question that remains to be answered is whether an environmental reservoir exists, containing potentially infective dinospores. Sediment and water samples were collected from various ecological sites within the Maryland Coastal Bays, and were analyzed using primers that are specific to the internal transcribed spacer (ITS) region of Hematodinium sp. We report here the detection of Hematodinium DNA within sediment and water samples from widely dispersed locations in the Maryland Coastal Bays. Q-PCR results were confirmed through direct cloning of a PCR fragment and comparison with genomic sequence deposited within Genbank. In support of these studies we are also undertaking an analysis of other resident dinoflagellate species in order to correlate environmental factors and ecological niches that may favor the presence of putative free-living Hematodinium sp. dinospores.