scholarly journals Perkinsus marinus Extracellular Protease Modulates Survival of Vibrio vulnificus in Eastern Oyster (Crassostrea virginica) Hemocytes

1999 ◽  
Vol 65 (9) ◽  
pp. 4261-4263 ◽  
Author(s):  
B. D. Tall ◽  
J. F. La Peyre ◽  
J. W. Bier ◽  
M. D. Miliotis ◽  
D. E. Hanes ◽  
...  
Keyword(s):  
Serine Protease ◽  
Crassostrea Virginica ◽  
Time Course ◽  
Vibrio Vulnificus ◽  
Eastern Oyster ◽  
Intracellular Survival ◽  
Extracellular Protease ◽  
Perkinsus Marinus ◽  
In Vitro Effects

ABSTRACT The in vitro effects of the Perkinsus marinus serine protease on the intracellular survival of Vibrio vulnificusin oyster hemocytes were examined by using a time-course gentamicin internalization assay. Results showed that protease-treated hemocytes were initially slower to internalize V. vulnificus than untreated hemocytes. After 1 h, the elimination of V. vulnificus by treated hemocytes was significantly suppressed compared with hemocytes infected with invasive and noninvasive controls. Our data suggest that the serine protease produced byP. marinus suppresses the vibriocidal activity of oyster hemocytes to effectively eliminate V. vulnificus, potentially leading to conditions favoring higher numbers of vibrios in oyster tissues.

Vibrio vulnificus Load Reduction in Oysters after Combined Exposure to Vibrio vulnificus–Specific Bacteriophage and to an Oyster Extract Component†

2005 ◽  
Vol 68 (6) ◽  
pp. 1188-1191 ◽  
Author(s):  
WILLIAM PELON ◽  
RONALD B. LUFTIG ◽  
KENNETH H. JOHNSTON
Keyword(s):  
Health Risk ◽  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Eastern Oyster ◽  
Load Reduction ◽  
Combined Exposure ◽  
In Vitro System ◽  
Iron Deficient ◽  
Specific Bacteriophage

Oysters infected with Vibrio vulnificus can present a serious health risk to diabetic, immunocompromised, and iron-deficient individuals. Numerous studies have been conducted with the goal of eliminating this organism from raw oysters. We utilized two natural oyster-associated components: pooled Vibrio vulnificus–specific bacteriophage and an extract of the eastern oyster (Crassostrea virginica) that contains an antimicrobial component we named anti–Vibrio vulnificus factor, which is bactericidal for V. vulnificus. Although each component alone can reduce V. vulnificus numbers independently, the simultaneous use of both components in an in vitro system successfully more effectively reduced V. vulnificus bacterial loads.

Host oyster tissue extracts modulate in vitro protease expression and cellular differentiation in the protozoan parasite, Perkinsus marinus

Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 293-302 ◽  
Author(s):  
E. A. MACINTYRE ◽  
C. G. EARNHART ◽  
S. L. KAATTARI
Keyword(s):  
Serine Proteases ◽  
Protozoan Parasite ◽  
Eastern Oyster ◽  
Defined Medium ◽  
Tissue Homogenate ◽  
Oyster Tissue ◽  
Perkinsus Marinus ◽  
Tissue Extracts

Perkinsus marinus is responsible for a chronic disease (Dermo) of the Eastern oyster, Crassostrea virginica. In order to simulate the in vivo environment more closely, a chemically defined medium (JL-ODRP-3) was supplemented with tissue homogenate extracts or plasma from oysters possessing varying degrees of susceptibility to P. marinus infection. In media supplemented with extracts from highly susceptible oysters (C. virginica), P. marinus cells secreted elevated amounts of a set of low molecular weight serine proteases (LMP: 30–45 kDa) as assessed by enhanced digestion within gelatin-substrate SDS–PAGE gels. Oyster species of low susceptibility (C. gigas and C. ariakensis) did not exhibit this ability to upregulate P. marinus LMP expression. Oyster extract supplementation also led to pronounced changes in P. marinus cellular morphology, such that the cells were comparable to those observed within naturally infected oysters.

Interaction of Vibrio vulnificus and the Eastern Oyster, Crassostrea virginica

1994 ◽  
Vol 57 (3) ◽  
pp. 224-228 ◽  
Author(s):  
TRUDI N. GROUBERT ◽  
JAMES D. OLIVER
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Health Hazard ◽  
Effective Means ◽  
Ultra Violet ◽  
Eastern Oyster ◽  
Human Pathogen ◽  
Specific Identification ◽  
Conversion Rates ◽  
Differential Medium

The estuarine bacterium, Vibrio vulnificus, is a human pathogen associated with the consumption of raw oysters. To date, no effective means exists for the elimination of this health hazard in oysters meant for raw consumption. The purpose of this study was to investígate the interaction between V. vulnificus and the eastern oyster. These studies were facilitated through the use of a strain of V. vulnificus containing a TnphoA transposon that allowed specific identification of the bacterium on a selective and differential médium. In studies employing ultra-violet assisted (UV-assisted) depuration, no differences were found in the oysters of the encapsulated (virulent) and nonencapsulated (avirulent) morphotypes of V. vulnificus. Both types were readily depurated from the oysters, while a naturally obtained microflora was shown not to depurate. Virulence of V. vulnificus and conversion rates between the virulent and avirulent morphotypes of this bacterium were found to be unchanged by oyster passage.

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