title: Reductions of Vibrio parahaemolyticus in Pacific oysters (Crassostrea gigas) by depuration at various temperatures.
abstract: Consumption of raw oysters has been linked to several outbreaks of Vibrio parahaemolyticus infection in the United States. This study investigated effects of ice storage and UV-sterilized seawater depuration at various temperatures on reducing V. parahaemolyticus in oysters. Raw Pacific oysters (Crassostrea gigas) were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10290, 10292, 10293, BE 98-2029 and 027-1c1) at levels of 10⁴⁻⁶ MPN/g. Inoculated oysters were either stored in ice or depurated in recirculating artificial seawater at 2, 3, 7, 10, 12.5, and 15 °C for 4-6 days. Holding oysters in ice or depuration of oysters in recirculating seawater at 2 or 3 °C for 4 days did not result in significant reductions (P > 0.05) of V. parahaemolyticus in the oysters. However, depuration at temperatures between 7 and 15 °C reduced V. parahaemolyticus populations in oysters by >3.0 log MPN/g after 5 days with no loss of oysters. Depuration at refrigerated temperatures (7-15 °C) can be applied as a post-harvest treatment for reducing V. parahaemolyticus in Pacific oysters.
authors.affiliation: Seafood Research and Education Center, Oregon State University, Astoria, OR 97103, USA.
authors.forename: Sureerat
authors.initials: S
authors.lastname: Phuvasate
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Chen
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Su
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D049896:Crassostrea / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D017747:Seafood / Q000032:analysis / Q000382:microbiology; D012623:Seawater; D013696:Temperature; D013997:Time Factors; D014736:Vibrio parahaemolyticus / Q000254:growth & development / Q000302:isolation & purification*