Perkinsus marinus, a protozoan parasite of the eastern oyster, has a requirement for dietary sterols

2007 ◽  
Vol 146 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Eric D. Lund ◽  
Fu-Lin E. Chu ◽  
Philippe Soudant ◽  
Ellen Harvey
Keyword(s):  
Protozoan Parasite ◽  
Eastern Oyster ◽  
Perkinsus Marinus ◽  
Dietary Sterols

Host oyster tissue extracts modulate in vitro protease expression and cellular differentiation in the protozoan parasite, Perkinsus marinus

Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 293-302 ◽  
Author(s):  
E. A. MACINTYRE ◽  
C. G. EARNHART ◽  
S. L. KAATTARI
Keyword(s):  
Serine Proteases ◽  
Protozoan Parasite ◽  
Eastern Oyster ◽  
Defined Medium ◽  
Tissue Homogenate ◽  
Oyster Tissue ◽  
Perkinsus Marinus ◽  
Tissue Extracts

Perkinsus marinus is responsible for a chronic disease (Dermo) of the Eastern oyster, Crassostrea virginica. In order to simulate the in vivo environment more closely, a chemically defined medium (JL-ODRP-3) was supplemented with tissue homogenate extracts or plasma from oysters possessing varying degrees of susceptibility to P. marinus infection. In media supplemented with extracts from highly susceptible oysters (C. virginica), P. marinus cells secreted elevated amounts of a set of low molecular weight serine proteases (LMP: 30–45 kDa) as assessed by enhanced digestion within gelatin-substrate SDS–PAGE gels. Oyster species of low susceptibility (C. gigas and C. ariakensis) did not exhibit this ability to upregulate P. marinus LMP expression. Oyster extract supplementation also led to pronounced changes in P. marinus cellular morphology, such that the cells were comparable to those observed within naturally infected oysters.

scholarly journals A rapid phenotype change in the pathogen Perkinsus marinus was associated with a historically significant marine disease emergence in the eastern oyster

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan B. Carnegie ◽  
Susan E. Ford ◽  
Rita K. Crockett ◽  
Peter R. Kingsley-Smith ◽  
Lydia M. Bienlien ◽  
...  
Keyword(s):  
South Carolina ◽  
Climatic Factors ◽  
Disease Outbreaks ◽  
Protozoan Parasite ◽  
Eastern Oyster ◽  
Perkinsus Marinus ◽  
Novel Ecosystem ◽  
The Usa ◽  
Exotic Pathogen ◽  
Dermo Disease

AbstractThe protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo’s intensification or the persistence of its intensified activity. Here we show that emergence of a unique, hypervirulent P. marinus phenotype was associated with the increase in prevalence and intensity of this disease and associated mortality. Retrospective histopathology of 8355 archival oysters from 1960 to 2018 spanning Chesapeake Bay, South Carolina, and New Jersey revealed that a new parasite phenotype emerged between 1983 and 1990, concurrent with major historical dermo disease outbreaks. Phenotypic changes included a shortening of the parasite’s life cycle and a tropism shift from deeper connective tissues to digestive epithelia. The changes are likely adaptive with regard to the reduced oyster abundance and longevity faced by P. marinus after rapid establishment of exotic pathogen Haplosporidium nelsoni in 1959. Our findings, we hypothesize, illustrate a novel ecosystem response to a marine parasite invasion: an increase in virulence in a native parasite.

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