Submitted to: Food and Environmental Virology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/19/2009
Publication Date: 12/1/2009
Citation: Kingsley, D.H., Calci, K., Holliman, S., Dancho, B.A., Flick, G. 2009. High pressure inactivation of HAV within oysters: comparison of shucked oysters with whole in shell meats. Food and Environmental Virology. 1:137-140. Interpretive Summary: Commercial high pressure processing treatments (HPP) of oysters are performed for several reasons. HPP is an approved intervention for Vibrio vulnificus, a naturally occurring pathogenic marine bacterium. HPP facilitates separation of the meat from the shell, or shucking. Consequently, commercial HPP treatments are performed with whole shell oysters. To date, all HPP inactivation work has been performed with manually-shucked shellfish to avoid the potential of sharp shells puncturing sealing bags and potential subsequent vessel contamination with viral pathogens. In this study, whole shell hepatitis A virus (HAV)-contaminated oysters were compared with shucked HAV-contaminated oysters over a range of pressure treatments. Results indicate that there are no significant inactivation differences for HAV. This work validates the assumption that results obtained for shucked oysters in a research setting will be valid for pressure applied to whole in-shell oysters in a commercial setting.
Technical Abstract: High pressure inactivation of hepatitis A virus (HAV) within oysters bioaccumulated under simulated natural conditions to levels >106 PFU/oyster has been evaluated. Five min treatments at 20C were administered at 350, 375, and 400 MegaPascals (MPa). Shucked and whole-in-shell oysters were directly compared to determine if there were any differences in inactivation levels. For whole-in shell-oysters and shucked oysters, average values obtained were 2.56 and 2.96 log10 inactivation of HAV respectively after a 400-MPa treatment. Results indicate that there is no significant inactivation difference (P= 0.05) between inactivation for whole in-shell oysters as compared to shucked oysters observed for all pressure treatments. This work indicates that commercial high pressure processing applied to whole in-shell oysters will be capable of inactivating HAV pathogens.