The protistan parasite Perkinsus marinus is resistant to selected reactive oxygen species.
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 (H(2)O(2)), but equally sensitive to hypochlorite. Viable P. marinus trophozoites degrade H(2)O(2) in vitro, but lack detectable catalase activity. However, extracts contain an ascorbate dependent peroxidase activity that may contribute to H(2)O(2) removal in vitro and in vivo.
Center of Marine Biotechnology, University of Maryland Biotechnology Institute, 701 East Pratt Street, Baltimore, MD 21202, USA.
Eric J
EJ
Schott
Wolf T
WT
Pecher
Florence
F
Okafor
Gerardo R
GR
Vasta
D000818:Animals; D060387:Ascorbate Peroxidases; D004351:Drug Resistance; D056890:Eukaryota / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D006997:Hypochlorous Acid / Q000494:pharmacology; D010125:Ostreidae / Q000469:parasitology*; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D013481:Superoxides / Q000494:pharmacology; D014733:Vibrio / Q000187:drug effects / Q000201:enzymology; D019820:Xanthine / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
D017382:Reactive Oxygen Species; D013481:Superoxides; D019820:Xanthine; D006997:Hypochlorous Acid; D006861:Hydrogen Peroxide; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D009195:Peroxidase; D014969:Xanthine Oxidase