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Predictive models for the effect of storage temperature on Vibrio parahaemolyticus viability and counts of total viable bacteria in Pacific oysters (Crassostrea gigas)


Fernandez-Piquer, J and Bowman, JP and Ross, T and Tamplin, ML, Predictive models for the effect of storage temperature on Vibrio parahaemolyticus viability and counts of total viable bacteria in Pacific oysters (Crassostrea gigas), Applied and Environmental Microbiology, 77, (24) pp. 8687-8695. ISSN 0099-2240 (2011) [Refereed Article]

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Copyright Statement

Copyright 2011 American Society for Microbiology

DOI: doi:10.1128/AEM.05568-11


Vibrio parahaemolyticus is an indigenous bacterium of marine environments. It accumulates in oysters and may reach levels that cause human illness when postharvest temperatures are not properly controlled and oysters are consumed raw or undercooked. Predictive models were produced by injecting Pacific oysters (Crassostrea gigas) with a cocktail of V. parahaemolyticus strains, measuring viability rates at storage temperatures from 3.6 to 30.4C, and fitting the data to a model to obtain parameter estimates. The models were evaluated with Pacific and Sydney Rock oysters (Saccostrea glomerata) containing natural populations of V. parahaemolyticus. V. parahaemolyticus viability was measured by direct plating samples on thiosulfate-citratebile salts-sucrose (TCBS) agar for injected oysters and by most probable number (MPN)-PCR for oysters containing natural populations. In parallel, total viable bacterial counts (TVC) were measured by direct plating on marine agar. Growth/inactivation rates for V. parahaemolyticus were 0.006, 0.004, 0.005, 0.003, 0.030, 0.075, 0.095, and 0.282 log10 CFU/h at 3.6, 6.2, 9.6, 12.6, 18.4, 20.0, 25.7, and 30.4C, respectively. The growth rates for TVC were 0.015, 0.023, 0.016, 0.048, 0.055, 0.071, 0.133, and 0.135 log10 CFU/h at 3.6, 6.2, 9.3, 14.9, 18.4, 20.0, 25.7, and 30.4C, respectively. Square root and Arrhenius-type secondary models were generated for V. parahaemolyticus growth and inactivation kinetic data, respectively. A square root model was produced for TVC growth. Evaluation studies showed that predictive growth for V. parahaemolyticus and TVC were "fail safe." The models can assist oyster companies and regulators in implementing management strategies to minimize V. parahaemolyticus risk and enhancing product quality in supply chains.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Microbiology
Research Field:Microbiology not elsewhere classified
Objective Division:Health
Objective Group:Public health (excl. specific population health)
Objective Field:Food safety
UTAS Author:Fernandez-Piquer, J (Dr Judith Fernandez-Piquer)
UTAS Author:Bowman, JP (Associate Professor John Bowman)
UTAS Author:Ross, T (Professor Tom Ross)
UTAS Author:Tamplin, ML (Professor Mark Tamplin)
ID Code:75346
Year Published:2011
Web of Science® Times Cited:31
Deposited By:Agricultural Science
Deposited On:2012-01-25
Last Modified:2017-11-01

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