Bioaccumulation, Retention, and Depuration of Enteric Viruses by Crassostrea virginica and Crassostrea ariakensis Oysters

TitleBioaccumulation, Retention, and Depuration of Enteric Viruses by Crassostrea virginica and Crassostrea ariakensis Oysters
Publication TypeJournal Article
Year of Publication2008
AuthorsNappier, SP, Graczyk, TK, Schwab, KJ
JournalApplied and Environmental Microbiology
Volume74
Issue22
Pagination6825 - 6831
Date Published2008
ISBN Number0099-2240
KeywordsAquaculture ER, Infection
Abstract

Crassostrea ariakensis oysters are under review for introduction into the Chesapeake Bay. However, the human health implications of the introduction have not been fully addressed. This study evaluated rates of bioaccumulation, retention, and depuration of viruses by Crassostrea virginica and C. ariakensis when the two oyster species were maintained in separate tanks containing synthetic seawater of various salinities (8, 12, or 20 ppt). Oyster bioaccumulation tanks were seeded with 10(3) PFU/ml of hepatitis A virus (HAV), poliovirus, male-specific bacteriophage (MS2), and murine norovirus 1 (MNV-1) and 10(3) PCR units/ml of human norovirus (NoV). After 24 h, depuration commenced as oysters (n = 255) were placed in pathogen-free seawater under continuous filtration. Oysters (n = 6) were sampled weekly for 1 month from each tank. Viral RNA was recovered using a modified proteinase K, guanidine, and glassmilk method and analyzed by quantitative reverse transcription-PCR. The odds of C. ariakensis oysters harboring NoV, MNV-1, or HAV were statistically greater than the odds of C. virginica oysters harboring the same viruses (MNV-1 odds ratio [OR], 4.5; P = 0.01; NoV OR, 8.4; P < 0.001; HAV OR, 11.4; P < 0.001). Unlike C. virginica, C. ariakensis bioaccumulated and retained NoV, MNV-1, and HAV for 1 month at all salinities. Additionally, the odds of an oyster testing positive for NoV was 25.5 times greater (P < 0.001) when the oyster also tested positive for MNV-1. This research helps assess the threat of C. ariakensis as a vehicle for viral pathogens due to the consumption of raw oysters and validates the role for MNV-1 as a surrogate for NoV.

Notes

PT: J; UT: BIOSIS:PREV200900000923