Inactivation of a calicivirus and enterovirus in shellfish by high pressure

This study demonstrates the potential of high pressure (HP) processing to reduce viral contamination in shellfish. Bovine enterovirus, which is structurally similar to hepatitis A virus, was more pressure-resistant than feline calicivirus, a surrogate for norovirus. Both viruses were more pressure-resistant when treated in "naturally" contaminated mussels and oysters, compared to seawater and culture medium, suggesting that the medium can have a significant protective effect against HP treatment. Treatment at pressures of 250 MPa showed only a limited inactivation of either virus in shellfish, suggesting that relatively mild HP treatments (approximately 260 MPa) currently used for the commercial processing of oysters, principally to assist the shucking process, may be insufficient to ensure the safety of shellfish for human consumption, particularly in relation to human pathogenic viruses. Industrial relevance: High pressure (HP) processing is increasingly being used in the commercial processing of oysters, principally to assist the opening or shucking of oysters. Little is known about the effect of HP treatment on pathogens in shellfish, particularly human enteric viruses, which are the predominant cause of shellfish-borne disease. This article demonstrates the inactivation of surrogate animal viruses, as potential models for noroviruses and hepatitis A virus, by HP processing and compares the efficacy of inactivation when viruses are treated in culture medium, seawater and shellfish. The potential of HP processing to reduce viral contamination in shellfish is discussed in light of these findings.