Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 17, 2010
Publication Date: N/A
Technical Abstract: Over the past 7 years, the USDA ARS Seafood Safety Laboratory has evaluated the potential use of high pressure processing (HPP) as a processing strategy for virus-contaminated shellfish. HPP can inactivate hepatitis A virus, (HAV), the human norovirus surrogates feline calicivirus and murine norovirus (MNV), as well as human norovirus (HuNoV) in shellfish, such as oysters and mussels. A 5-min 400-MegaPascals (MPa) treatment at 5 deg C and a 1–min 400-MPa treatment at 9 deg C are sufficient to inactivate 4.05 and 3.15 log10 plaque-forming units (PFU) of MNV and HAV within oysters, respectively. For blue mussels, log10 PFU reductions of HAV averaged 2.1 and 3.6 for treatments of 350 MPa and 400 MPa, while for Mediterranean mussels, reductions of 1.7 and 2.9 log10 PFU were observed for equivalent treatments. Recent studies showed that a 5-min, 400-MPa treatment of 1000 PFU of MNV within oyster extract was sufficient to protect STAT-1 -/- mice from infection after oral ingestion. Since HuNoV cannot be readily propagated in vitro, a human volunteer study was performed to evaluate the potential for high pressure to inactivate HuNoV directly within oysters. Treatment of 600 MPa inactivated at least 4-log10 of HuNoV in seeded oysters, while treatments of 400 MPa (at 6 deg or 25 deg C) were not sufficient to prevent infection of volunteers. Overall results indicate that HPP can inactivate HAV and HuNoV in shellfish although the pressures required are somewhat higher than those currently used commercially to inactivate Vibrio bacteria.