Survey of Postharvest-Processed Oysters in the United States for Levels of Vibrio vulnificus and Vibrio parahaemolyticus

2009 ◽  
Vol 72 (10) ◽  
pp. 2110-2113 ◽  
Author(s):  
ANGELO DePAOLA ◽  
JESSICA L. JONES ◽  
KATHY E. NOE ◽  
ROBIN H. BYARS ◽  
JOHN C. BOWERS
Keyword(s):  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Virulence Gene ◽  
Selective Advantage ◽  
The United States ◽  
Most Probable Number ◽  
Probable Number ◽  
Mild Heat ◽  
Thermostable Direct Hemolysin ◽  
The Mean

From June through October 2004, the U.S. Food and Drug Administration collected oysters (61 samples) that had been subjected to postharvest processing (PHP) methods, including mild heat treatment, freezing, and high hydrostatic pressure, from processors and retail markets in various states to determine Vibrio vulnificus and V. parahaemolyticus levels. Presence in a 25-g sample and most probable number (MPN) using standard enrichment and selective isolation procedures were utilized. Suspect colonies were isolated and identified using DNA probe colony hybridization. Neither species of vibrio was detected in 25-g portions of most samples regardless of the PHP. The lowest frequency of isolation of either pathogen (<10%) was observed with the mild heat process. Few (12 to 13%) frozen samples collected at the processor but not at retail contained >30 MPN/g of either pathogen. The mean levels of either organism in PHP oysters observed in the present study were 5 to 6 log less than in unprocessed raw Gulf Coast oysters. Of the 70 V. vulnificus isolates examined, only 5 possessed the putative virulence marker, type B 16S rRNA. Neither the thermostable direct hemolysin (tdh) nor the tdh-related hemolysin (trh) virulence gene was detected in any of the 40 V. parahaemolyticus isolates examined in the present study. These data suggest that if there is any selective advantage to pathogenic strains of V. vulnificus and V. parahaemolyticus, these differences are minimal. These results indicate that all PHP treatments greatly reduce exposure of V. vulnificus and V. parahaemolyticus to raw-oyster consumers. Consequently, these PHP oysters pose a much lower risk of illness to consumers due to these pathogens.

Vibrio vulnificus and Vibrio parahaemolyticus in U.S. Retail Shell Oysters: A National Survey from June 1998 to July 1999

2002 ◽  
Vol 65 (1) ◽  
pp. 79-87 ◽  
Author(s):  
DAVID W. COOK ◽  
PAUL O'LEARY ◽  
JEFF C. HUNSUCKER ◽  
EDNA M. SLOAN ◽  
JOHN C. BOWERS ◽  
...  
Keyword(s):  
United States ◽  
North Atlantic ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
The United States ◽  
Most Probable Number ◽  
Probable Number ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin

From June 1998 to July 1999, 370 lots of oysters in the shell were sampled at 275 different establishments (71%, restaurants or oyster bars; 27%, retail seafood markets; and 2%, wholesale seafood markets) in coastal and inland markets throughout the United States. The oysters were harvested from the Gulf (49%), Pacific (14%), Mid-Atlantic (18%), and North Atlantic (11%) Coasts of the United States and from Canada (8%). Densities of Vibrio vulnificus and Vibrio parahaemolyticus were determined using a modification of the most probable number (MPN) techniques described in the Food and Drug Administration's Bacteriological Analytical Manual. DNA probes and enzyme immunoassay were used to identify suspect isolates and to determine the presence of the thermostable direct hemolysin gene associated with pathogenicity of V. parahaemolyticus. Densities of both V. vulnificus and V. parahaemolyticus in market oysters from all harvest regions followed a seasonal distribution, with highest densities in the summer. Highest densities of both organisms were observed in oysters harvested from the Gulf Coast, where densities often exceeded 10,000 MPN/g. The majority (78%) of lots harvested in the North Atlantic, Pacific, and Canadian Coasts had V. vulnificus densities below the detectable level of 0.2 MPN/g; none exceeded 100 MPN/g. V. parahaemolyticus densities were greater than those of V. vulnificus in lots from these same areas, with some lots exceeding 1,000 MPN/g for V. parahaemolyticus. Some lots from the Mid-Atlantic states exceeded 10,000 MPN/g for both V. vulnificus and V. parahaemolyticus. Overall, there was a significant correlation between V. vulnificus and V. parahaemolyticus densities (r = 0.72, n = 202, P < 0.0001), but neither density correlated with salinity. Storage time significantly affected the V. vulnificus (10% decrease per day) and V. parahaemolyticus (7% decrease per day) densities in market oysters. The thermostable direct hemolysin gene associated with V. parahaemolyticus virulence was detected in 9 of 3,429 (0.3%) V. parahaemolyticus cultures and in 8 of 198 (4.0%) lots of oysters. These data can be used to estimate the exposure of raw oyster consumers to V. vulnificus and V. parahaemolyticus.

scholarly journals Prevalence of Pandemic Thermostable Direct Hemolysin-Producing Vibrio parahaemolyticus O3:K6 in Seafood and the Coastal Environment in Japan

2003 ◽  
Vol 69 (7) ◽  
pp. 3883-3891 ◽  
Author(s):  
Yukiko Hara-Kudo ◽  
Kanji Sugiyama ◽  
Mitsuaki Nishibuchi ◽  
Ashrafuzzaman Chowdhury ◽  
Jun Yatsuyanagi ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
The United States ◽  
Most Probable Number ◽  
Asian Countries ◽  
Probable Number ◽  
Specific Pcr ◽  
Thermostable Direct Hemolysin ◽  
Chromogenic Agar ◽  
Pcr Method ◽  
Arbitrarily Primed Pcr

ABSTRACT Although thermostable direct hemolysin (TDH)-producing Vibrio parahaemolyticus has caused many infections in Asian countries, the United States, and other countries, it has been difficult to detect the same pathogen in seafoods and other environmental samples. In this study, we detected and enumerated tdh gene-positive V. parahaemolyticus in Japanese seafoods with a tdh-specific PCR method, a chromogenic agar medium, and a most-probable-number method. The tdh gene was detected in 33 of 329 seafood samples (10.0%). The number of tdh-positive V. parahaemolyticus ranged from <3 to 93/10 g. The incidence of tdh-positive V. parahaemolyticus tended to be high in samples contaminated with relatively high levels of total V. parahaemolyticus. TDH-producing strains of V. parahaemolyticus were isolated from 11 of 33 tdh-positive samples (short-necked clam, hen clam, and rock oyster). TDH-producing strains of V. parahaemolyticus were also isolated from the sediments of rivers near the coast in Japan. Representative strains of the seafood and sediment isolates were examined for the O:K serovar and by the PCR method specific to the pandemic clone and arbitrarily primed PCR and pulsed-field gel electrophoresis techniques. The results indicated that most O3:K6 tdh-positive strains belonged to the pandemic O3:K6 clone and suggested that serovariation took place in the Japanese environment.

Effect of Frozen Storage and Vacuum-Packaging on Survival of Vibrio Vulnificus in Gulf Coast Oysters (Crassostrea virginica)

1994 ◽  
Vol 57 (7) ◽  
pp. 604-606 ◽  
Author(s):  
ROGER W. PARKER ◽  
ELLEN M. MAURER ◽  
A. BILL CHILDERS ◽  
DONALD H. LEWISI
Keyword(s):  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Health Hazard ◽  
Frozen Storage ◽  
Polymyxin B ◽  
Aerobic Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Alkaline Peptone Water ◽  
Peptone Water

Vibrio vulnificus contamination of raw oysters is a serious public health hazard, therefore, it is necessary to investigate the persistence of V. vulnificus in harvested and stored oysters. For this study, triplicate oyster samples were split into four treatment groups: control, normal-packaged; control, vacuum-packaged; inoculated, normal-packaged; and inoculated, vacuum-packaged. Oysters in the inoculated groups were individually injected with V. vulnificus to a level of approximately 1 × 106 CFU/g. Control oysters were already naturally contaminated to a level of approximately 1 × 104 CFU/g. Oysters were then packaged, frozen and stored at −20°C. On day 0 and days 7, 14, 30 and 70 post-freezing, concentrations of total aerobic bacteria and V. vulnificus were determined using a 3-tube most probable number (MPN) estimation from enrichment Alkaline Peptone Water tubes with subsequent presumptive V. vulnificus growth on modified Cellobiose-Polymyxin B-Colistin agar. Length of frozen storage had a significant effect on decreasing total aerobic bacteria (from approximately 106 CFU/g to approximately 102.5 CFU/g) and V. vulnificus (from approximately 105 CFU/g to approximately 101 CFU/g). Also, vacuum-packaged samples showed significantly lower concentrations of V. vulnificus over the length of the study than did the normal-sealed samples.

Effects of Dry Storage and Resubmersion of Oysters on Total Vibrio vulnificus and Total and Pathogenic (tdh+/trh+) Vibrio parahaemolyticus Levels

2015 ◽  
Vol 78 (8) ◽  
pp. 1574-1580 ◽  
Author(s):  
THOMAS P. KINSEY ◽  
KERI A. LYDON ◽  
JOHN C. BOWERS ◽  
JESSICA L. JONES
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Storage Time ◽  
Vibrio Vulnificus ◽  
Ambient Air ◽  
Most Probable Number ◽  
Probable Number ◽  
Ambient Temperatures ◽  
Dry Storage ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin

Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are the two leading causes of bacterial illnesses associated with raw shellfish consumption. Levels of these pathogens in oysters can increase during routine antifouling aquaculture practices involving dry storage in ambient air conditions. After storage, common practice is to resubmerge these stored oysters to reduce elevated Vv and Vp levels, but evidence proving the effectiveness of this practice is lacking. This study examined the changes in Vv and in total and pathogenic (thermostable direct hemolysin gene and the tdh-related hemolysin gene, tdh+ and trh+) Vp levels in oysters after 5 or 24 h of dry storage (28 to 32°C), followed by resubmersion (27 to 32°C) for 14 days. For each trial, replicate oyster samples were collected at initial harvest, after dry storage, after 7 days, and after 14 days of resubmersion. Oysters not subjected to dry storage were collected and analyzed to determine natural undisturbed vibrio levels (background control). Vibrio levels were measured using a most-probable-number enrichment followed by real-time PCR. After storage, vibrio levels (excluding tdh+ and trh+ Vp during 5-h storage) increased significantly (P &lt; 0.001) from initial levels. After 7 days of resubmersion, Vv and total Vp levels (excluding total Vp in oysters stored for 5 h) were not significantly different (P &gt; 0.1) from levels in background oysters. Vv and total and pathogenic Vp levels were not significantly different (P &gt; 0.1) from levels in background oysters after 14 days of resubmersion, regardless of dry storage time. These data demonstrate that oyster resubmersion after dry storage at elevated ambient temperatures allows vibrio levels to return to those of background control samples. These results can be used to help minimize the risk of Vv and Vp illnesses and to inform the oyster industry on the effectiveness of routine storing and resubmerging of aquaculture oysters.

scholarly journals Influence of Water Temperature and Salinity onVibrio vulnificus in Northern Gulf and Atlantic Coast Oysters (Crassostrea virginica)

1998 ◽  
Vol 64 (4) ◽  
pp. 1459-1465 ◽  
Author(s):  
M. L. Motes ◽  
A. DePaola ◽  
D. W. Cook ◽  
J. E. Veazey ◽  
J. C. Hunsucker ◽  
...  
Keyword(s):  
South Carolina ◽  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
Environmental Parameters ◽  
Late Summer ◽  
Most Probable Number ◽  
Probable Number ◽  
The North ◽  
North Carolina Estuary

This study investigated the temperature and salinity parameters associated with waters and oysters linked to food-borne Vibrio vulnificus infections. V. vulnificus was enumerated in oysters collected at three northern Gulf Coast sites and two Atlantic Coast sites from July 1994 through September 1995. Two of these sites, Black Bay, La., and Apalachicola Bay, Fla., are the source of the majority of the oysters implicated in V. vulnificuscases. Oysters in all Gulf Coast sites exhibited a similar seasonal distribution of V. vulnificus: a consistently large number (median concentration, 2,300 organisms [most probable number] per g of oyster meat) from May through October followed by a gradual reduction during November and December to ≤10 per g, where it remained from January through mid-March, and a sharp increase in late March and April to summer levels. V. vulnificus was undetectable (<3 per g) in oysters from the North and South Carolina sites for most of the year. An exception occurred when a late-summer flood caused a drop in salinity in the North Carolina estuary, apparently causing V. vulnificus numbers to increase briefly to Gulf Coast levels. At Gulf Coast sites, V. vulnificus numbers increased with water temperatures up to 26°C and were constant at higher temperatures. High V. vulnificus levels (>103per g) were typically found in oysters from intermediate salinities (5 to 25 ppt). Smaller V. vulnificus numbers (<102 per g) were found at salinities above 28 ppt, typical of Atlantic Coast sites. On 11 occasions oysters were sampled at times and locations near the source of oysters implicated in 13V. vulnificus cases; the V. vulnificuslevels and environmental parameters associated with these samples were consistent with those of other study samples collected from the Gulf Coast from April through November. These findings suggest that the hazard of V. vulnificus infection is not limited to brief periods of unusual abundance of V. vulnificus in Gulf Coast oysters or to environmental conditions that are unusual to Gulf Coast estuaries.

Evaluation of Ice Slurries as a Control for Postharvest Growth of Vibrio spp. in Oysters and Potential for Filth Contamination

2015 ◽  
Vol 78 (7) ◽  
pp. 1375-1379 ◽  
Author(s):  
KERI ANN LYDON ◽  
MELISSA FARRELL-EVANS ◽  
JESSICA L. JONES
Keyword(s):  
Vibrio Vulnificus ◽  
The United States ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Internal Cooling ◽  
Probable Number ◽  
Route Of Exposure ◽  
C 50 ◽  
Vibrio Spp

Raw oyster consumption is the most common route of exposure for Vibrio spp. infections in humans. Vibriosis has been increasing steadily in the United States despite efforts to reduce the incidence of the disease. Research has demonstrated that ice is effective in reducing postharvest Vibrio spp. growth in oysters but has raised concerns of possible contamination of oyster meat by filth (as indicated by the presence of fecal coliform bacteria or Clostridium perfringens). This study examined the use of ice slurries (&lt;4.5°C) to reduce Vibrio growth. Ice slurries showed rapid internal cooling of oysters, from 23.9°C (75°F) to 10°C (50°F) within 12 min. The initial bacterial loads in the ice slurry waters were near the limits of detection. Following repeated dipping of oysters into ice slurries, water samples exhibited significant (P &lt; 0.05) increases in median levels of fecal coliforms (9.5 most probable number [MPN]/100 ml), C. perfringens (280 MPN/100 ml), Vibrio vulnificus (11,250 MPN/ml), and total Vibrio parahaemolyticus (3,900 MPN/ml). The microbial load in oyster meat, however, was unchanged after 15 min of submergence, with no significant differences (P &lt; 0.05) in levels of filth indicator (range, 250 to 720 MPN/100 g) or Vibrio spp. (range, 9,000 to 20,000 MPN/g) bacteria. These results support the use of ice slurries as a postharvest application for rapid cooling of oysters to minimize Vibrio growth.

scholarly journals Effects of Intertidal Harvest Practices on Levels of Vibrio parahaemolyticus and Vibrio vulnificus Bacteria in Oysters

2016 ◽  
Vol 82 (15) ◽  
pp. 4517-4522 ◽  
Author(s):  
J. L. Jones ◽  
T. P. Kinsey ◽  
L. W. Johnson ◽  
R. Porso ◽  
B. Friedman ◽  
...  
Keyword(s):  
New Jersey ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Ambient Air ◽  
The United States ◽  
Washington State ◽  
Most Probable Number ◽  
Probable Number ◽  
Content Type ◽  
Handling Practices

ABSTRACTVibrio parahaemolyticusandVibrio vulnificuscan grow rapidly in shellfish subjected to ambient air conditions, such as during intertidal exposure. In this study, levels of total and pathogenic (tdh+and/ortrh+)V. parahaemolyticusand totalV. vulnificuswere determined in oysters collected from two study locations where intertidal harvest practices are common. Samples were collected directly off intertidal flats, after exposure (ambient air [Washington State] or refrigerated [New Jersey]), and after reimmersion by natural tidal cycles. Samples were processed using a most-probable-number (MPN) real-time PCR method for total and pathogenicV. parahaemolyticusorV. vulnificus. In Washington State, the mean levels ofV. parahaemolyticusincreased 1.38 log MPN/g following intertidal exposure and dropped 1.41 log MPN/g after reimmersion for 1 day, but the levels were dependent upon the container type utilized. PathogenicV. parahaemolyticuslevels followed a similar trend. However,V. vulnificuslevels increased 0.10 log MPN/g during intertidal exposure in Washington but decreased by >1 log MPN/g after reimmersion. In New Jersey, initial levels of all vibrios studied were not significantly altered during the refrigerated sorting and containerizing process. However, there was an increase in levels after the first day of reimmersion by 0.79, 0.72, 0.92, and 0.71 log MPN/g for total,tdh+andtrh+V. parahaemolyticus, andV. vulnificus, respectively. The levels of all targets decreased to those similar to background after a second day of reimmersion. These data indicate that the intertidal harvest and handling practices for oysters that were studied in Washington and New Jersey do not increase the risk of illness fromV. parahaemolyticusorV. vulnificus.IMPORTANCEVibrio parahaemolyticusandVibrio vulnificusare the leading causes of seafood-associated infectious morbidity and mortality in the United States.Vibriospp. can grow rapidly in shellfish subjected to ambient air conditions, such as during periods of intertidal exposure. When oysters are submersed with the incoming tide, the vibrios can be purged. However, data on the rates of increase and purging during intertidal harvest are scarce, which limits the accuracy of risk assessments. The objective of this study was to help fill these data gaps by determining the levels of total and pathogenic (tdh+and/ortrh+)V. parahaemolyticusandV. vulnificusin oysters from two locations where intertidal harvest practices are common, using the current industry practices. The data generated provide insight into the responses ofVibriospp. to relevant practices of the industry and public health, which can be incorporated into risk management decisions.

scholarly journals Abundance of Vibrio cholerae, V. vulnificus, and V. parahaemolyticus in Oysters (Crassostrea virginica) and Clams (Mercenaria mercenaria) from Long Island Sound

2014 ◽  
Vol 80 (24) ◽  
pp. 7667-7672 ◽  
Author(s):  
Jessica L. Jones ◽  
Catharina H. M. Lüdeke ◽  
John C. Bowers ◽  
Kristin DeRosia-Banick ◽  
David H. Carey ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Vibrio Vulnificus ◽  
Long Island ◽  
Long Island Sound ◽  
The United States ◽  
Mitigation Strategies ◽  
Most Probable Number ◽  
Probable Number ◽  
Content Type ◽  
Island Sound

ABSTRACTVibriosis is a leading cause of seafood-associated morbidity and mortality in the United States. Typically associated with consumption of raw or undercooked oysters, vibriosis associated with clam consumption is increasingly being reported. However, little is known about the prevalence ofVibriospp. in clams. The objective of this study was to compare the levels ofVibrio cholerae,Vibrio vulnificus, andVibrio parahaemolyticusin oysters and clams harvested concurrently from Long Island Sound (LIS). Most probable number (MPN)–real-time PCR methods were used for enumeration of totalV. cholerae,V. vulnificus,V. parahaemolyticus, and pathogenic (tdh+and/ortrh+)V. parahaemolyticus.V. choleraewas detected in 8.8% and 3.3% of oyster (n= 68) and clam (n= 30) samples, with levels up to 1.48 and 0.48 log MPN/g in oysters and clams, respectively.V. vulnificuswas detected in 97% and 90% of oyster and clam samples, with median levels of 0.97 and −0.08 log MPN/g, respectively.V. parahaemolyticuswas detected in all samples, with median levels of 1.88 and 1.07 log MPN/g for oysters and clams, respectively. The differences betweenV. vulnificusand total and pathogenicV. parahaemolyticuslevels in the two shellfish species were statistically significant (P< 0.001). These data indicate thatV. vulnificusand total and pathogenicV. parahaemolyticusare more prevalent and are present at higher levels in oysters than in hard clams. Additionally, the data suggest differences in vibrio populations between shellfish harvested from different growing area waters within LIS. These results can be used to evaluate and refine illness mitigation strategies employed by risk managers and shellfish control authorities.

Evaluation of DNA Colony Hybridization and Real-Time PCR for Detection of Vibrio parahaemolyticus and Vibrio vulnificus in Postharvest-Processed Oysters

2009 ◽  
Vol 72 (10) ◽  
pp. 2106-2109 ◽  
Author(s):  
JESSICA L. JONES ◽  
KATHY E. NOE ◽  
ROBIN BYARS ◽  
ANGELO DePAOLA
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
The United States ◽  
Most Probable Number ◽  
Probable Number ◽  
Colony Hybridization ◽  
Alkaline Peptone Water ◽  
Peptone Water

The applicability of real-time PCR was examined for detection of vibrios from postharvest-processed (PHP) oysters to allow for a more rapid assay and higher sample throughput than currently used. During June to October 2004, 68 PHP oyster samples were collected directly from PHP firms or from retail markets across the United States. PHP oysters were examined to determine the effectiveness of treatments in the reduction of vibrio levels and to compare the analytical methods utilized. The latter is the focus of the data presented here. Each sample was analyzed for Vibrio parahaemolyticus and V. vulnificus by using a 2-dilution, three-tube most-probable-number (MPN) and a 25-g presence/absence enrichment in alkaline peptone water. Following 6-h and overnight enrichment, aliquots from each MPN tube and the 25-g sample were streaked onto selective media and tested by real-time PCR. Colonies from the selective agar were confirmed as V. parahaemolyticus or V. vulnificus by DNA colony hybridization. DNA hybridization and real-time PCR results for each MPN tube and the 25-g enrichment at both time points were analyzed individually for each organism. The methods were in agreement for 857 (95%) of 901 and for 882 (98%) of 903 tubes for detection of V. parahaemolyticus and V. vulnificus, respectively. Overall, there was 96% agreement between real-time and DNA colony hybridization. The results obtained by real-time PCR were comparable to those from DNA colony hybridization, but analysis time was significantly reduced for the detection of vibrios in PHP-treated oysters.

Effects of a Commercial Heat-Shock Process on Vibrio vulnificus in the American Oyster, Crassostrea virginica, Harvested from the Gulf Coast

1999 ◽  
Vol 62 (11) ◽  
pp. 1266-1269 ◽  
Author(s):  
DONALD M. HESSELMAN ◽  
MILES L. MOTES ◽  
JAMES P. LEWIS
Keyword(s):  
Heat Shock ◽  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Most Probable Number ◽  
American Oyster ◽  
Probable Number ◽  
Shock Process ◽  
Shellfish Sanitation

Oysters (Crassostrea virginica) harvested from the Gulf Coast, containing 102 to 104 most probable number (MPN) per gram of Vibrio vulnificus, were subjected to a commercial heat-shock process. After 1 to 4 min at internal oyster meat temperatures exceeding 50°C, shellstock oysters were shucked, chilled, washed, and packed. V. vulnificus and total bacterial levels in Gulf Coast oysters were significantly reduced from 1 to 4 logs in the finished product. Similar reductions were not observed in shellstock oysters that were subject to conventional processing. Under the National Shellfish Sanitation Program, heat shocking is an acceptable process to use to assist in the shucking of shellstock. This research revealed that the heat-shock process may also serve to significantly reduce V. vulnificus in summer Gulf Coast oysters.

Sign in / Sign up

Export Citation Format

Share Document