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United States Department of Agriculture

Agricultural Research Service

Title: Uptake, Persistence, and Localization of Virulent and Avirulent Vibrio Vulnificus in the Eastern Oyster, Crassostrea Virginica

Authors
item Parveen, Salina - DELAWARE STATE UNIVERSITY
item Wolfe, William
item Richards, Gary

Submitted to: Meeting Abstract
Publication Type: Other
Publication Acceptance Date: February 6, 2003
Publication Date: May 18, 2003
Citation: PARVEEN, S., WOLFE, W.C., RICHARDS, G.P. UPTAKE, PERSISTENCE, AND LOCALIZATION OF VIRULENT AND AVIRULENT VIBRIO VULNIFICUS IN THE EASTERN OYSTER, CRASSOSTREA VIRGINICA. MEETING ABSTRACT. 2003.

Technical Abstract: Vibrio vulnificus is a human pathogen commonly found in estuarine environments. Foodborne illness is associated with the consumption of raw oysters and can produce gastroenteritis and life-threatening septicemia. Depuration is one of the common methods to purge microbial contaminants from oysters. Laboratory-grown V. vulnificus can be depurated from oysters and natural V. vulnificus can persist in oysters throughout depuration; however, no information is available about the uptake, persistence and localization of virulent and avirulent V. vulnificus in oysters. The objectives of this study were: (a) to determine if strains virulent to humans are more or less likely to be taken up, bound or purged from oysters than avirulent strains, and (b) to localize virulent and avirulent strains within the oyster tissues by immunohistochemistry. For the uptake experiment, V. vulnificus-free oysters were exposed for 24 h to seawater containing 10(6) CFU of V. vulnificus/ml. After 1.5 h exposure, both strains exceeded 10(3) V. vulnificus/g of oyster tissue. However, the counts of both virulent and avirulent strains remained >10(4)/g of oyster tissue from 15 h through 24 h. Depuration was carried out under controlled physiological condition using UV and non-UV treated water for 6 days. After 6 days, V. vulnificus counts per gram of oyster were reduced from 2.3x10(5) to 2.3x10(2) for virulent and from 2.3x10(5) to 7.5x10(1) for avirulent strains in UV-treated water. In non-UV treated water, virulent counts decreased from 9.3x10(4) to 9.3x10(2) and avirulent from 2.3x10(4) to 7.3x10(1)/g of oyster. The virulent strain of V. vulnificus was localized only in the hemocytes using immunohistochemistry. It can be concluded that the persistence of virulent and avirulent strains of V. vulnificus in oysters in UV treated water was less than that of oysters in non-UV treated water, and the virulent strain was more persistent than the avirulent strain. Depuration is ineffective in eliminating virulent and avirulent strains of V. vulnificus from oysters.

Last Modified: 9/22/2014
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