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.

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 CRISPR/Cas9 Ribonucleoprotein-Based Genome Editing Methodology in the Marine Protozoan Parasite Perkinsus marinus

2021 ◽  
Vol 9 ◽  
Author(s):  
Raghavendra Yadavalli ◽  
Kousuke Umeda ◽  
Hannah A. Waugh ◽  
Adrienne N. Tracy ◽  
Asha V. Sidhu ◽  
...  
Keyword(s):  
Heterologous Gene Expression ◽  
Protozoan Parasite ◽  
Close Relative ◽  
Perkinsus Marinus ◽  
Post Transfection ◽  
Expression Platform ◽  
C Terminus ◽  
Gene Expression Platform ◽  
Optimized Protocol ◽  
Dermo Disease

Perkinsus marinus (Perkinsozoa), a close relative of apicomplexans, is an osmotrophic facultative intracellular marine protozoan parasite responsible for “Dermo” disease in oysters and clams. Although there is no clinical evidence of this parasite infecting humans, HLA-DR40 transgenic mice studies strongly suggest the parasite as a natural adjuvant in oral vaccines. P. marinus is being developed as a heterologous gene expression platform for pathogens of medical and veterinary relevance and a novel platform for delivering vaccines. We previously reported the transient expression of two rodent malaria genes Plasmodium berghei HAP2 and MSP8. In this study, we optimized the original electroporation-based protocol to establish a stable heterologous expression method. Using 20 μg of pPmMOE[MOE1]:GFP and 25.0 × 106P. marinus cells resulted in 98% GFP-positive cells. Furthermore, using the optimized protocol, we report for the first time the successful knock-in of GFP at the C-terminus of the PmMOE1 using ribonucleoprotein (RNP)-based CRISPR/Cas9 gene editing methodology. The GFP was expressed 18 h post-transfection, and expression was observed for 8 months post-transfection, making it a robust and stable knock-in system.

scholarly journals Disposable swim diaper retention of Cryptosporidium-sized particles on human subjects in a recreational water setting

2011 ◽  
Vol 9 (4) ◽  
pp. 653-658 ◽  
Author(s):  
James E. Amburgey ◽  
J. Brian Anderson
Keyword(s):  
Human Subject ◽  
Human Subjects ◽  
Disease Outbreaks ◽  
Protozoan Parasite ◽  
Bulk Water ◽  
Recreational Water ◽  
Swimming Pools ◽  
Polystyrene Microspheres ◽  
Cryptosporidium Oocysts ◽  
The Usa

Cryptosporidium is a chlorine-resistant protozoan parasite responsible for the majority of waterborne disease outbreaks in recreational water venues in the USA. Swim diapers are commonly used by diaper-aged children participating in aquatic activities. This research was intended to evaluate disposable swim diapers for retaining 5-μm diameter polystyrene microspheres, which were used as non-infectious surrogates for Cryptosporidium oocysts. A hot tub recirculating water without a filter was used for this research. The microsphere concentration in the water was monitored at regular intervals following introduction of microspheres inside of a swim diaper while a human subject undertook normal swim/play activities. Microsphere concentrations in the bulk water showed that the majority (50–97%) of Cryptosporidium-sized particles were released from the swim diaper within 1 to 5 min regardless of the swim diaper type or configuration. After only 10 min of play, 77–100% of the microspheres had been released from all swim diapers tested. This research suggests that the swim diapers commonly used by diaper-aged children in swimming pools and other aquatic activities are of limited value in retaining Cryptosporidium-sized particles. Improved swim diaper solutions are necessary to efficiently retain pathogens and effectively safeguard public health in recreational water venues.

scholarly journals Perkinsus marinus in the pleasure oyster Crassostrea corteziensis cultivated on the southeast coast of the Gulf of California, Mexico

2020 ◽  
Vol 48 (4) ◽  
pp. 529-537
Author(s):  
Lizeth Carolina Villanueva-Fonseca ◽  
Manuel García-Ulloa ◽  
Melina López-Meyer ◽  
Brenda Paulina Villanueva-Fonseca ◽  
Juan Antonio Hernández-Sepúlveda ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Infection Intensity ◽  
Eastern Oyster ◽  
Perkinsus Marinus ◽  
Water Parameters ◽  
Southeast Coast ◽  
Pathogen Prevalence ◽  
The Usa ◽  
Oyster Farms ◽  
Crassostrea Corteziensis

The protozoan Perkinsus marinus has been associated with high mortality episodes of the eastern oyster Crassostrea virginica in the USA. The presence of P. marinus on the pleasure oyster Crassostrea corteziensis cultivated in two estuaries on the southeast coast of the Gulf of California was evaluated. Oysters were collected monthly (September 2016 to September 2017) and analyzed using Ray's fluid thioglycollate medium (RFTM) and polymerase chain reaction (PCR). Water parameters and oyster biometrics were also recorded. Pathogen prevalence increased over time from 0 to 100% in oysters from La Pitahaya, and from 0 to 83.33% in those from Bacorehuis. At both oyster farms, infection intensity was light (<1×104 parasites g-1 wet tissue), pathogen prevalence and infection intensity were correlated with oyster size and weight, and there was a strong correlation between P. marinus prevalence and intensity (La Pitahaya r = 0.91; Bacorehuis r = 0.82). The oysters that resulted positive for P. marinus by RFTM also were assayed using PCR. P. marinus presence was confirmed in 98.27% (114/116) of the oysters from La Pitahaya, and 95.83% (46/48) of those from Bacorehuis. The detection of P. marinus confirms that this pathogen is well established in the area with high expression during the warmer season. Despite the light infection intensity of this parasite at both sites, health surveillance of this bivalve in the region is highly advisable.

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