Department of Environmental & Aquatic Animal Health - Research Programs & Projects

Shellfish Pathology Laboratory 

Program Overview

Since the late 1950s oyster populations of Chesapeake Bay have been significantly impacted by two oyster pathogens: Haplosporidium nelsoni, the causative agent of MSX disease, and Perkinsus marinus, the causative agent of perkinsosis or Dermo. These protozoan parasites have caused severe mortalities in Chesapeake Bay oyster populations, contributing to their decline and hindering their restoration. Scientists at VIMS have been studying these parasites since their discovery. Today, the VIMS Shellfish Pathology Laboratory continues research on these and other shellfish disease agents so that we may better understand the biology of these pathogens and use that information to mitigate effects on regional shellfish populations and industries.

Our current research focuses on native oyster pathogens H. nelsoni, H. costale (seaside organism, SSO), and P. marinus; hard clam parasite QPX (Quahog Parasite Unknown); and on the known and potential disease agents of the Asian oyster species Crassostrea ariakensis, including Bonamia spp. We have specific interests in:

• Developing molecular diagnostic methods for parasite detection.
• Applying molecular tools to determine environmental reservoirs for parasites.
• Understanding environmental influences on the distribution and abundance of shellfish pathogens.
• Determining parasite life cycles and transmission dynamics.
• Understanding the genetic basis in shellfish of disease susceptibility and resistance.

In addition to our research programs, our laboratory also monitors the distribution and abundance of oyster and clam diseases in Virginia, provides shellfish health examinations for industry, and serves as the world’s OIE Reference Laboratory for Perkinsus and Haplosporidian shellfish pathogens.

Current and Recent Research  

Infectivity and transmissibility to Crassostrea ariakensis of pathogenic Bonamia sp. from Ostrea equestris: Evaluation of crested oysters as a parasite reservoir. R.B. Carnegie, E.M. Burreson and C. Audemard. Virginia Sea Grant. 2005-2007.

Examination of the Potential for Vertical and Horizontal Transmission of the Oyster Herpes Virus from Crassostrea ariakensis Broodstock. K.S. Reece, R.B. Carnegie, E.M. Burreson, and C. Dungan (Maryland Department of Natural Resources). Virginia Sea Grant. 2005-2007.

Pathogenic Bonamia sp. from North Carolina: Field and laboratory trials to characterize potential risks to C. ariakensis in the mid-Atlantic region. E.M. Burreson, R.B. Carnegie, C. Audemard, and C. Peterson and M. Bishop (University of North Carolina Institute of Marine Sciences). NOAA Chesapeake Bay Office. 2004-2005.

Potential for Crassostrea ariakensis to serve as a vector for exotic pathogens in Chesapeake Bay: Assessing the risk of Perkinsus spp. and oyster herpes virus to C. ariakensis and native bivalves. K.S. Reece, E.M. Burreson, R.B. Carnegie, and C. Dungan (Maryland Department of Natural Resources). NOAA Chesapeake Bay Office. 2004-2006.

Determination of the natural host for Bonamia sp. in North Carolina, and evaluation of the potential for infection of Crassostrea ariakensis in Virginia. R.B. Carnegie and E.M. Burreson. Virginia Sea Grant. 2004

Susceptibility of Crassostrea ariakensis to the oyster pathogen Bonamia ostreae to Bonamia sp. recently discovered in C. ariakensis in North Carolina. E.M. Burreson, C. Audemard, and R.B. Carnegie. Maryland Department of Natural Resources. 2004-2005

Publications

Annual Monitoring Reports   

Carnegie, R. and E.M. Burreson. 2006. Status of the major oyster diseases in Virginia—2005. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report.   

Carnegie, R. and E.M. Burreson. 2005. Status of the major oyster diseases in Virginia—2004. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report.   

Carnegie, R., L. Ragone Calvo, and E.M. Burreson. 2004. Status of the major oyster diseases in Virginia—2003. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report.   

Ragone Calvo, L. and E.M. Burreson. 2003. Status of the major oyster diseases in Virginia—2002. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report, 2003-. 

Ragone Calvo, L. and E.M. Burreson. 2002. Status of the major oyster diseases in Virginia—2001. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report, 2002-1. 

Ragone Calvo, L. and E.M. Burreson. 2001. Status of the major oyster diseases in Virginia—2000. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report, 01-08. 

Ragone Calvo, L. and E.M. Burreson. 2000. Status of the major oyster diseases in Virginia—1999. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report, 00-2. 

Ragone Calvo, L. and E.M. Burreson. 1999. Status of the major oyster diseases in Virginia—1998. A summary of the annual monitoring program. Virginia Institute of Marine Science Marine Resource Report, 99-3. 

Peer Reviewed Journal Articles 

Bishop, M.J., R.B. Carnegie, N.A. Stokes, C.H. Peterson, and E.M. Burreson. 2006. Predicting the outcome of a non-native oyster introduction: facilitation of an enzootic parasite. Marine Ecology Progress Series, 325: 145-152.

Hare, M.P., S.K. Allen, Jr., P. Bloomer, M.D. Camara, R.B. Carnegie, J. Murfree, M. Luckenbach, D. Meritt, C. Morrison, K. Paynter, K.S. Reece, and C.G. Rose. 2006. A genetic test for recruitment enhancement in Chesapeake Bay oysters, Crassostrea virginica, after population supplementation with a disease tolerant strain. Conservation Genetics 7: 717-734.

Camara, M.D., S.K. Allen, Jr., R.B. Carnegie, and K.S. Reece. 2006. Out-crossing among commercial strains of the northern quahog, Mercenaria mercenaria: Survival, growth, and implications for selective breeding. Journal of Shellfish Research 25(2): 403-416.

Carnegie, R.B., E.M. Burreson, P.M. Hine, N.A. Stokes, C. Audemard, M.J. Bishop, and C.H. Peterson. 2006. Bonamia perspora n. sp. (Haplosporidia), a parasite of the oyster Ostreola equestris, is the first Bonamia species known to produce spores. Journal of Eukaryotic Microbiology 53(4): 232-245.

Audemard, C., L. M. Ragone Calvo, K. T. Paynter, K. S. Reece, E. M. Burreson. 2006. Real-time PCR investigation of parasite ecology: in situ determination of oyster parasite Perkinsus marinus transmission dynamics in lower Chesapeake Bay. Parasitology 132: 827-842.

Moss, J. A., E. M. Burreson, and K. S. Reece. 2006. Advanced Perkinsus marinus infections in Crassostrea ariakensis maintained under laboratory conditions. Journal of Shellfish Research 25(1): 65-72.

Azevedo, C., P Balseiro, G. Casal, C. Gestal, R. Aranguren, N.A. Stokes, R.B. Carnegie, B. Novoa, E.M. Burreson, and A. Figueras. 2006. Ultrastructural and molecular characterization of Haplosporidium montforti n. sp., parasite of the European abalone Haliotis tuberculata. Journal of Invertebrate Pathology 92: 23-32.

Johnson, P.T.J., J.E. Longcore, D.E. Stanton, R.B. Carnegie, J.D. Shields, and E.R. Preu. 2006. Chytrid fungal infections of Daphnia pulicaria: development, ecology, pathology and phylogeny of Polycaryum laeve. Freshwater Biology 51: 634-648.

Burreson, E.M., K.S. Reece, and C.F. Dungan. 2005. Molecular, morphological, and experimental evidence support the synonymy of Perkinsus chesapeaki and Perkinsus andrewsi. Journal of Eukaryotic Microbiology 52: 258-270.

Meyer, G.R., S.M. Bower, and R.B. Carnegie. 2005. Sensitivity of a digoxigenin-labelled DNA probe in detecting Mikrocytos mackini, causative agent of Denman Island Disease (mikrocytosis) in oysters. Journal of Invertebrate Pathology 88: 89-94.

Reece, K.S., M.E. Siddall, N.A. Stokes, and E.M. Burreson. 2004. Molecular phylogeny of the Haplosporidia based on two independent gene sequences. Journal of Parasitology 90 (5): 1111-1122.

Carnegie, R.B., and N. Cochennec-Laureau. 2004. Microcell parasites of oysters: Recent insights and future trends. Aquatic Living Resources 17: 519-528.

Burreson, E.M., and S.E. Ford. 2004. A review of recent information on the Haplosporidia, with special reference to Haplosporidium nelsoni (MSX disease). Aquatic Living Resources 17: 499-517.

Audemard, C., K. S. Reece, E. M. Burreson. 2004. Development of real-time PCR for the detection and quantification of the protistan parasite Perkinsus marinus. Appl. Environ. Microbiol. 70: 6611-6618.

Audemard, C., M.-C. Sajus, A. Barnaud, B. Sautour, P.-G. Sauriau, F. J. C. Berthe. 2004. Infection dynamics of Marteilia refringens in flat oyster Ostrea edulis and copepod Paracartia grani in a claire pond of Marennes-Oléron Bay. Dis. Aquat. Org. 61: 103-111.

Burreson, E.M., N.A. Stokes, R.B. Carnegie, and M.J. Bishop. 2004. Bonamia sp. (Haplosporidia) found in non-native oysters, Crassostrea ariakensis, in Bogue Sound, North Carolina. Journal of Aquatic Animal Health 16 (1): 1-9.

Bower, S.M., R.B. Carnegie, B. Goh, S.R.M. Jones, G.J. Lowe, and M.W.S. Mak. 2004. Preferential PCR amplification of parasitic protistan SSU rDNA from metazoan tissues. J. Eukaryotic Microbiology 51 (3): 325-332.

Litaker, R.W., M.W. Vandersea, S.R. Kibler, K.S. Reece, N.A. Stokes, K.A. Steidinger, D.F. Millie, B.J. Bendis, R.J. Pigg, and P.A. Tester. 2003. Identification of Pfiesteria piscicida (Dinophyceae) and Pfiesteria-like organisms using internal transcribed spacer-specific PCR assays. Journal of Phycology 39: 754-761.

Carnegie, R.B., G.R. Meyer, J. Blackbourn, N. Cochennec-Laureau, F.C.J. Berthe, and S.M. Bower. 2003. Molecular detection of the oyster parasite Mikrocytos mackini, and a preliminary phylogenetic analysis. Diseases of Aquatic Organisms 54(3): 219-227.

Anderson, R.S., B.S. Kraus, S.E. McGladdery, K.S. Reece, and N.A. Stokes. 2003. A thraustochytrid protist isolated from Mercenaria mercenaria: molecular characterization and host defense responses. Fish & Shellfish Immunology 15: 183-194.

Ragone Calvo, L. M., C. F. Dungan, B. S. Roberson and E. M. Burreson. 2003. A systematic evaluation of factors controlling Perkinsus marinus transmission dynamics in the lower Chesapeake Bay. Diseases of Aquatic Organisms 56: 75-86.

Ragone Calvo, L. M., G. W. Calvo, and E. M. Burreson. 2003. Dual disease resistance in a selectively-bred eastern oyster, Crassostrea virginica, strain tested in Chesapeake Bay. Aquaculture. 220(1-4):69-87

Burreson, E. M. 2001. Spore ornamentation of Haplosporidium pickfordi, a parasite of freshwater snails in Michigan. J. Eukaryotic Microbiol. 48(6): 622-626.

Calvo, G. W., M. W. Luckenbach, S. K. Allen and E. M. Burreson.  2001.  A comparative field study of Crassostrea ariakensis (Thundberg 1793) and Crassostrea virginica (Gmelin 1791) in relation to salinity in Virginia.  J. Shellfish Res. 20: 221-229.  

Stokes, N. A. and E. M. Burreson.  2001.  Differential diagnosis of mixed infections of Haplosporidium nelsoni (MSX) and Haplosporidium costale (SSO) using DNA probes.  J. Shellfish Res. 20: 207-213.  

Ragone Calvo, L. M., R. L. Wetzel and E. M. Burreson.  2001.  Development and verification of a model for the population dynamics of the protistan parasite Perkinsus marinus within its host, the eastern oyster Crassostrea virginica.  J. Shellfish. Res. 20: 231-241.  

Burreson, E. M., N. A. Stokes and C. S. Friedman.  2000.  Increased virulence in an introduced pathogen: Haplosporidium nelsoni in the eastern oyster Crassostrea virginica.  J. Aquatic Animal Health 12: 1-8. (Invited feature article).  

Renault, T., N. A. Stokes, B. Chollet, N. Cochennec, F. Berthe, A. Gérard, and E. M. Burreson.  2000.  Haplosporidiosis in the Pacific oyster Crassostrea gigas from the French Atlantic coast.  Dis. Aquatic Org. 42: 207-214.  

O’Farrell, C. L., K. T. Paynter and E. M. Burreson.  2000.  Osmotic tolerance and volume regulation in in vitro cultures of the oyster pathogen Perkinsus marinus.  J. Shellf. Res. 19(10; 133-138.  

Yarnall, H. A., K. S. Reece, N. A. Stokes and E. M. Burreson.  2000.  A quantitative competitive polymerase chain reaction assay for the oyster pathogen Perkinsus marinus.  J. Parasitol. 86(4): 827-837.  

Calvo, G. W., M. W. Luckenbach, S. K. Allen and E. M. Burreson.  2000.  A comparative field study of Crassostrea gigas (Thunberg 1793) and Crassostrea virginica (Gmelin 1791) in relation to salinity in Virginia.  J. Shellfish Res. 18: 465-474.  

Berthe, F. C. J., E. M. Burreson and M. Hine.  1999.  Use of molecular tools for mollusc disease diagnosis.  Bull. European Assoc. Fish Pathol. 19: 277-278.  

Ragone Calvo, L.M. and J.G. Walker and E.M. Burreson. 1998. Prevalence and distribution of QPX, Quahog Parasite Unknown, in hard clams, Mercenaria mercenaria in Virginia.  Diseases of Aquatic Organisms. 33:209-219.  

Oliver, L.M., W.S. Fisher, S.E. Ford, L.M. Ragone Calvo, E.M. Burreson, E.B. Sutton, J. Gandy. 1998. Perkinsus marinus distribution and seasonal variation in oysters Crassostrea virginica from Florida, Virginia and New York. Diseases of Aquatic Organisms. 34:51-61.  

Anderson, R.S., L.L. Brubacher, L.M. Ragone Calvo, E.M. Burreson and M.A. Unger. 1998. Effect of in vitro exposure to tributyltin and hypoxia on the progression of Perkinsus marinus infections and host defense mechanism in oysters, Crassostrea virginica (Gmelin). Journal of Fish Diseases 21:371-380.  

Ford, S.E., R. Smolowitz, L.M. Ragone Calvo, R.D. Barber, and J.N. Kraeuter. 1997.  Evidence that QPX (Quahog Parasite Unknown) is not present in hatchery-produced hard clam seed.  Journal of Shellfish Research. 16(2):519-521.  

Anderson, R.S., L.L. Brubacher, L.M. Ragone Calvo, E.M. Burreson and M.A. Unger. 1997. Effect of in vitro exposure to tributyltin on gene ration of oxygen metabolites by oyster hemocytes. Environmental Research. 74:84-90.  

Burreson, E.M. and L. Ragone Calvo. 1996. Epizootiology of Perkinsus marinus  disease of oysters in Chesapeake Bay, with emphasis on data since 1985. Journal of Shellfish Research Special Publication. Journal of Shellfish Research. 15(1):17-34.  

Technical and Advisory Reports 

Ragone Calvo, L.M., N.A. Stokes, and E.M. Burreson. 2001. Molecular methods for the detection of Quahog Parasite Unknown (QPX). Marine Resource Report No. 2001-10, Virginia Institute of Marine Science, Gloucester Point, Virginia.  

Ragone Calvo, L.M. and E.M. Burreson. 2002. QPX susceptibility in hard clams varies with geographic origin of brood stock. Virginia Sea Grant Marine Resource advisory No. 74 VSG-02-18, Virginia Institute of Marine Science, Gloucester Point, Virginia.

Personnel 

• Dr. Eugene Burreson
• Dr. Ryan Carnegie
• Dr. Corinne Audemard
• Ms. Nancy A. Stokes
• Ms. Rita Crockett
• Ms. Susan Denny
• Ms. Kristina Hill

Contact Us 

Eugene M. Burreson
Professor of Marine Science
804-684-7015  FAX: 804-684-7796
gene@vims.edu

Ryan B. Carnegie
Assistant Research Scientist
804-684-7713  FAX: 804-684-7796
carnegie@vims.edu

Nancy Stokes
Marine Scientist Senior
804-684-7410 FAX: 804-684-7796 
stokes@vims.edu 

Rita Crockett
Marine Scientist Senior
804-684-7451  FAX: 804-684-7796
rita@vims.edu

Department of Environmental and Aquatic Animal Health
Virginia Institute of Marine Science
P.O. Box 1346 (for mail)
Route 1208 Greate Road (for FedEx, UPS)
Gloucester Point, VA 23062 USA

Questions/comments regarding the design of this website should be directed to Gregory Mears.

(This page was last updated 11/20/2006 )