Science Serving Maryland's Coasts

Research Publications: UM-SG-RS-2003-17


The protistan parasite Perkinsus marinus is resistant to selected reactive oxygen species.




Schott, EJ; Pecher, WT; Okafor, F; Vasta, GR


Experimental Parasitology 105(34):232-240




The parasite Perkinsus marinus has devastated natural and farmed oyster populations along the Atlantic and Gulf coasts of North America. When viable P. marinus trophozoites are engulfed by oyster hemocytes, the typical accumulation of reactive oxygen species (ROS) normally associated with phagocyte activity is not observed. One hypothesis to explain this is that the parasite rapidly removes ROS. A manifestation of efficient ROS removal should be a high level of resistance to exogenous ROS. We investigated the in vitro susceptibility of P. marinus to ROS as compared to the estuarine bacterium Vibrio splendidus. We find that P. marinus is markedly less susceptible than V splendidus to superoxide and hydrogen peroxide (H2O2), but equally sensitive to hypochlorite. Viable P. marinus trophozoites degrade H2O2 in vitro, but lack detectable catalase activity. However, extracts contain an ascorbate dependent peroxidase activity that may contribute to H2O2 removal in vitro and in vivo.

Related Research Project(s) Funded by Maryland Sea Grant: 

Maryland Sea Grant Topic(s): 

'Related Research Project(s)' link to details about research projects funded by Maryland Sea Grant that led to this publication. These details may include other impacts and accomplishments resulting from the research.

'Maryland Sea Grant Topic(s)' links to related pages on the Maryland Sea Grant website.