Effectiveness of Icing as a Postharvest Treatment for Control of Vibrio vulnificus and Vibrio parahaemolyticus in the Eastern Oyster (Crassostrea virginica)

2008 ◽  
Vol 71 (7) ◽  
pp. 1475-1480 ◽  
Author(s):  
KEVIN MELODY ◽  
RESHANI SENEVIRATHNE ◽  
MARLENE JANES ◽  
LEE ANN JAYKUS ◽  
JOHN SUPAN
Keyword(s):  
Crassostrea Virginica ◽  
Cold Storage ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Storage Period ◽  
Eastern Oyster ◽  
Pathogenic Vibrio ◽  
Postharvest Treatment ◽  
Shellfish Sanitation ◽  
Vibrio Spp

The focus of this research was to investigate the efficacy of icing as a postharvest treatment for reduction of the levels of Vibrio vulnificus and Vibrio parahaemolyticus in commercial quantities of shellstock oysters. The experiments were conducted in June and August of 2006 and consisted of the following treatments: (i) on-board icing immediately after harvest; (ii) dockside icing approximately 1 to 2 h prior to shipment; and (iii) no icing (control). Changes in the levels of pathogenic Vibrio spp. during wholesale and retail handling for 2 weeks postharvest were also monitored. On-board icing achieved temperature reductions in all sacks in accordance with the National Shellfish Sanitation Program standard, but dockside icing did not meet this standard. Based on one-way analysis of variance, the only statistically significant relationship between Vibrio levels and treatment occurred for samples harvested in August; in this case, the levels of V. vulnificus in the noniced oysters were significantly higher (P < 0.05) than were the levels in the samples iced on-board. When analyzing counts over the 14-day storage period, using factorial analysis, there were statistically significant differences in V. vulnificus and V. parahaemolyticus levels by sample date and/or treatment (P < 0.05), but these relationships were not consistent. Treated (iced) oysters had significantly higher gaping (approximately 20%) after 1 week in cold storage than did noniced oysters (approximately 10%) and gaping increased significantly by day 14 of commercial storage. On-board and dockside icing did not predictably reduce the levels of V. vulnificus or V. parahaemolyticus in oysters, and icing negatively impacted oyster survival during subsequent cold storage.

Effect of Ploidy on Vibrio parahaemolyticus and Vibrio vulnificus Levels in Cultured Oysters

2020 ◽  
Vol 83 (11) ◽  
pp. 2014-2017
Author(s):  
JESSICA L. JONES ◽  
KERI A. LYDON ◽  
WILLIAM C. WALTON
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
High Quality ◽  
Colony Hybridization ◽  
Naturally Occurring ◽  
Rapid Growth Rate ◽  
Vibrio Spp ◽  
Half Sibling

ABSTRACT Vibrio parahaemolyticus and Vibrio vulnificus are naturally occurring human pathogenic bacteria commonly found in estuarine environments where oysters are cultured. The use of triploid oysters has increased due to their rapid growth rate and because they maintain a high quality throughout the year. Previous work suggested levels of Vibrio spp. may be lower in triploid oysters than diploid oysters. Therefore, this study aimed to determine whether there is a difference in the abundances of V. parahaemolyticus and V. vulnificus between half-sibling diploid and triploid American oysters (Crassostrea virginica). In four trials, 100 individual oysters (either iced or temperature abused) were analyzed for V. parahaemolyticus and V. vulnificus by using direct plating followed by colony hybridization. Mean levels of V. parahaemolyticus in iced and abused diploid oysters were 3.55 and 4.21 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.49 and 4.27 log CFU/g, respectively. Mean levels of V. vulnificus in iced and abused diploid oysters were 3.53 and 4.56 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.54 and 4.55 log CFU/g, respectively. The differences in Vibrio spp. abundances between diploid and triploid oysters was not significant (P > 0.05). However, the differences across treatments were significant (P < 0.05), with the exception of V. parahaemolyticus levels in trial 3 (P = 0.83). Variation between individual oysters was also observed, with 12 of 808 measurements being outside of the 95th percentile. This phenomenon of occasional statistical outliers (“hot” or “cold” oysters) has been previously described and supports the appropriateness of composite sampling to account for inherent animal variability. In summary, the data indicate that abundances of V. parahaemolyticus and V. vulnificus are not dependent on the ploidy of cultured oysters but vary with the type of handling. HIGHLIGHTS

Long-Term Depuration of Crassostrea virginica Oysters at Different Salinities and Temperatures Changes Vibrio vulnificus Counts and Microbiological Profile

2018 ◽  
Vol 82 (1) ◽  
pp. 22-29
Author(s):  
OLEKSANDR TOKARSKYY ◽  
DOUGLAS L. MARSHALL ◽  
JEFF DILLON ◽  
LINDA S. ANDREWS
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Eastern Oyster ◽  
Population Count ◽  
Psychrotrophic Bacteria ◽  
Log Reduction ◽  
Long Duration ◽  
Plate Counts ◽  
Vibrio Spp

ABSTRACT Previous short-duration depuration studies with the eastern oyster (Crassostrea virginica) demonstrated difficulty in achieving significant naturally incurred Vibrio vulnificus population count reductions. The present study used long-duration depuration (14 days) at controlled temperatures (10 or 22°C) and salinities (12, 16, or 20 mg/g). All depuration temperature–salinity combinations significantly reduced V. vulnificus counts, with greatest reductions seen in 12 mg/g, 10°C seawater (2.7-log CFU/g reduction) and in 20 mg/g, 22°C seawater (2.8-log reduction). Mesophilic vibrios dominated the overall microflora of freshly harvested oysters, whereas refrigerated storage selected for psychrotrophic bacteria (Pseudomonas spp., Aeromonas spp., Shewanella spp., Psychrobacter spp.) as well as did depuration at 10°C (Pseudoalteromonas spp., Shewanella spp., Vibrio spp.). Depuration at 22°C retained dominance of mesophilic vibrios, including pathogenic species, followed by Shewanella spp., Pseudoalteromonas spp., and Photobacterium spp. Although aerobic plate counts were lower in 22°C depurated oysters (5.0 log versus 6.0 log) compared with 10°C, depuration at 10°C offered greater V. vulnificus population reductions than depuration at 22°C. This advantage was only seen at 12 mg/g salinity, with no impact at 16 and 20 mg/g salinities. No depuration treatment reduced V. vulnificus counts to nondetectable levels. Use of prolonged depuration may be a helpful intervention to control V. vulnificus populations in oysters.

Multiplex PCR assay for identification of three major pathogenic Vibrio spp., Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus

2011 ◽  
Vol 25 (4) ◽  
pp. 174-176 ◽  
Author(s):  
Hidemasa Izumiya ◽  
Kazutoshi Matsumoto ◽  
Shunsuke Yahiro ◽  
Jiyoung Lee ◽  
Masatomo Morita ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Vibrio Cholerae ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Pcr Assay ◽  
Multiplex Pcr Assay ◽  
Pathogenic Vibrio ◽  
Vibrio Spp

Selectivity and Specificity of a Chromogenic Medium for Detecting Vibrio parahaemolyticus†

2005 ◽  
Vol 68 (7) ◽  
pp. 1454-1456 ◽  
Author(s):  
YI-CHENG SU ◽  
JINGYUN DUAN ◽  
WEN-HSIN WU
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Bile Salts ◽  
Vibrio Vulnificus ◽  
Enterobacter Cloacae ◽  
Most Probable Number ◽  
Chromogenic Medium ◽  
Probable Number ◽  
Vibrio Fluvialis ◽  
Vibrio Mimicus ◽  
Vibrio Spp

The thiosulfate–citrate–bile salts–sucrose agar (TCBS) used in the most-probable-number method for detecting Vibrio parahaemolyticus cannot differentiate growth of V. parahaemolyticus from Vibrio vulnificus or Vibrio mimicus. This study examined the selectivity and specificity of Bio-Chrome Vibrio medium (BCVM), a chromogenic medium that detects V. parahaemolyticus on the basis of the formation of distinct purple colonies on the medium. A panel consisting of 221 strains of bacteria, including 179 Vibrio spp. and 42 non-Vibrio spp., were examined for their ability to grow and produce colored colonies on BCVM. Growth of Salmonella, Shigella, Escherichia coli, Enterobacter cloacae, Yersinia enterocolitica, and Aeromonas was inhibited by both BCVM and TCBS. All 148 strains of V. parahaemolyticus grew on BCVM, and 145 of them produced purple colonies. The remaining 31 Vibrio spp., except one strain of Vibrio fluvialis, were either unable to grow or produced blue-green or white colonies on BCVM. Bio-Chrome Vibrio medium was capable of differentiating V. parahaemolyticus from other species, including V. vulnificus and V. mimicus. Further studies are needed to evaluate the sensitivity and specificity of BCVM for detecting V. parahaemolyticus in foods.

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.

Prevalence of Vibrio spp. in Retail Seafood in Berlin, Germany

2018 ◽  
Vol 81 (4) ◽  
pp. 593-597 ◽  
Author(s):  
THI THU TRA VU ◽  
THOMAS ALTER ◽  
STEPHAN HUEHN
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
International Organization ◽  
Cross Contamination ◽  
Virulence Markers ◽  
Significant Difference ◽  
High Prevalence ◽  
The Difference ◽  
Prevalent Species ◽  
Vibrio Spp

ABSTRACT This study was conducted to determine the prevalence of Vibrio spp. in retail seafood in Berlin, Germany. A total of 160 raw seafood samples from supermarkets and seafood shops, consisting of shrimp (n = 80) and bivalves (n = 80), were investigated for the presence of Vibrio spp. using the International Organization for Standardization ISO/TS 21872 method and a multiplex PCR. The overall prevalence of Vibrio spp. in retail seafood was 55% (95% CI: 47.2 to 62.8%). The prevalence of Vibrio spp. in shrimp was slightly higher than in bivalves (57.5 versus 52.5%); however, the difference was not statistically significant. Vibrio alginolyticus was the most prevalent species (35.6%), followed by Vibrio parahaemolyticus (27.5%), Vibrio cholerae (6.3%), and Vibrio vulnificus (0.6%). None of the V. parahaemolyticus (n = 110) isolates encoded tdh/trh genes, whereas all V. cholerae isolates (n = 27) were lacking ctxA. Among the chilled samples (n = 105), the prevalence of Vibrio spp. in unpacked samples was significantly higher than in packed samples (P = 0.006). Among the packed samples (n = 55), no significant difference in the prevalence of Vibrio spp. was observed between chilled or frozen products. The results of this study indicated a high prevalence of Vibrio spp. in retail seafood in Germany; positive samples were detected in all types of seafood investigated. The detection of tdh/trh-negative V. parahaemolyticus isolates should not be neglected because of previous findings on pathogenic strains lacking these virulence markers. Even though thorough cooking might limit the risk of foodborne illness caused by Vibrio, potential cross-contamination during preparation or consumption of raw and undercooked seafood might represent a risk of Vibrio infections.

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.

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