Prevalence of Perkinsus marinus (Dermo), Haplosporidium nelsoni (MSX), and QPX in Bivalves of Delaware's Inland Bays and Quantitative, High-Throughput Diagnosis of Dermo by QPCR

• Published in: The Journal of eukaryotic microbiology Vol. 54; no. 6; pp. 520 - 526
• Main Authors: ULRICH, PAUL N, EWART, JOHN W, MARSH, ADAM G
• Format: Journal Article
• Language: English
• Published: Malden, USA Malden, USA : Blackwell Publishing Inc 01.11.2007; Blackwell Publishing Inc; Blackwell
• Subjects: Animals; Aquaculture; Biological and medical sciences; Bivalve disease; clams; Crassostrea - parasitology; Delaware; Dermo; DNA, Protozoan - analysis; DNA, Protozoan - isolation & purification; DNA, Ribosomal - analysis; Eukaryota - classification; Eukaryota - genetics; Eukaryota - isolation & purification; Fundamental and applied biological sciences. Psychology; Haplosporida - classification; Haplosporida - genetics; Haplosporida - isolation & purification; Invertebrates; Mercenaria - parasitology; Mollusca; MSX; oysters; Pathology; Polymerase Chain Reaction - methods; QPCR; quantitative; Seawater; Sensitivity and Specificity; Shellfish - parasitology; Delaware; United States; North America; America; Brackish water environment; Protozoa; Apicomplexa; Edible mollusc; Prevalence; oysters; Disease; Estuaries; Parasite; QPCR; Zoopathogen; MSX; Bivalvia; Crassostrea virginica; Pathogenic; quantitative; Diagnosis; clams; Invertebrata; Mollusca; Sanitary surveillance; Bivalve disease; Dermo; Quantitative analysis
• ISSN: 1066-5234; 1550-7408
• DOI: 10.1111/j.1550-7408.2007.00293.x

Restoration of oyster reef habitat in the Inland Bays of Delaware was accompanied by an effort to detect and determine relative abundance of the bivalve pathogens Perkinsus marinus, Haplosporidium nelsoni, and QPX. Both the oyster Crassostrea virginica and the clam Mercenaria mercenaria were sampled from the bays. In addition, oysters were deployed at eight sites around the bays as sentinels for the three parasites. Perkinsus marinus prevalence was measured with a real-time, quantitative polymerase chain reaction (PCR) methodology that enabled high-throughput detection of as few as 31 copies of the ribosomal non-transcribed spacer region in 500 ng oyster DNA. The other pathogens were assayed using PCR with species-specific primers. Perkinsus marinus was identified in Indian River Bay at moderate prevalence (~40%) in both an artificial reef and a wild oyster population whereas sentinel oysters were PCR-negative after 3-months exposure during summer and early fall. Haplosporidium nelsoni was restricted to one oyster deployed in Little Assawoman Bay. QPX and P. marinus were not detected among wild clams. While oysters in these bays have historically been under the greatest threat by MSX, it is apparent that P. marinus currently poses a greater threat to recovery of oyster aquaculture in Delaware's Inland Bays.