Effects of farm location on Vibrio parahaemolyticus and V. vulnificus levels in oysters after desiccation and resubmersion in the northern Gulf of Mexico

2021 ◽  
Author(s):  
Madison McGough ◽  
Victoria L Pruente ◽  
William C Walton ◽  
Jessica L Jones
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Gulf Coast ◽  
Geographic Location ◽  
Most Probable Number ◽  
Probable Number ◽  
Geographic Locations ◽  
Shell Quality ◽  
Increased Risk ◽  
Routine Handling ◽  
Ambient Levels

Desiccation is a routine farming practice utilized in off-bottom oyster aquaculture to reduce biofouling organisms and improve shell quality. This practice can increase Vibrio parahaemolyticus and V. vulnificus levels, leading to increased risk of illness for raw oyster consumers. Previous resubmersion studies were performed in geographic proximity to one another, so to better understand the broader applicability of resubmersion, the next step was to perform concurrent studies in multiple geographic locations within a region. This study evaluated the effect of variations in geographic location on the recovery time needed for elevated vibrio levels to return to ambient levels in desiccated oysters after resubmersion at Gulf Coast farms. Two trials were performed between May-August 2019 at sites spanning ~100 km: three in Alabama and one in Florida. Oysters were deployed in OysterGro cages at each location, two weeks prior to each trial, then either desiccated for 24 h or remained submersed as controls. Triplicate samples were taken prior to and immediately following the desiccation period, as well as 7 and 14 d post-resubmersion. Total and pathogenic ( tdh +/ trh +) V. parahaemolyticus , and V. vulnificus levels were determined using most probable number (MPN) real-time PCR. Vibrio levels increased by 0.23-3.50 log MPN/g after desiccation. Recovery times varied among geographic locations by trial and Vibrio spp., with all vibrio counts recovering to levels not significantly higher than those in control oysters within 7-14 days of resubmersion (p≥0.06). These results suggest a 14-day resubmersion period of cultured oysters allowed vibrio levels, elevated due to routine handling, to return to ambient levels at all farm sites studied.

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.

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.

scholarly journals Long-Term Study of Vibrio parahaemolyticus Prevalence and Distribution in New Zealand Shellfish

2015 ◽  
Vol 81 (7) ◽  
pp. 2320-2327 ◽  
Author(s):  
C. D. Cruz ◽  
D. Hedderley ◽  
G. C. Fletcher
Keyword(s):  
New Zealand ◽  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Pcr Analysis ◽  
Potential Hazard ◽  
Probable Number ◽  
Content Type ◽  
The North ◽  
Long Term Study ◽  
Food Borne

ABSTRACTThe food-borne pathogenVibrio parahaemolyticushas been reported as being present in New Zealand (NZ) seawaters, but there have been no reported outbreaks of food-borne infection from commercially grown NZ seafood. Our study determined the current incidence ofV. parahaemolyticusin NZ oysters and Greenshell mussels and the prevalence ofV. parahaemolyticustdhandtrhstrains. Pacific (235) and dredge (21) oyster samples and mussel samples (55) were obtained from commercial shellfish-growing areas between December 2009 and June 2012. TotalV. parahaemolyticusnumbers and the presence of pathogenic genestdhandtrhwere determined using the FDA most-probable-number (MPN) method and confirmed using PCR analysis. In samples from the North Island of NZ,V. parahaemolyticuswas detected in 81% of Pacific oysters and 34% of mussel samples, while the numbers ofV. parahaemolyticustdhandtrhstrains were low, with just 3/215 Pacific oyster samples carrying thetdhgene.V. parahaemolyticusorganisms carryingtdhandtrhwere not detected in South Island samples, andV. parahaemolyticuswas detected in just 1/21 dredge oyster and 2/16 mussel samples. Numbers ofV. parahaemolyticusorganisms increased when seawater temperatures were high, the season when most commercial shellfish-growing areas are not harvested. The numbers ofV. parahaemolyticusorganisms in samples exceeded 1,000 MPN/g only when the seawater temperatures exceeded 19°C, so this environmental parameter could be used as a trigger warning of potential hazard. There is some evidence that the totalV. parahaemolyticusnumbers increased compared with those reported from a previous 1981 to 1984 study, but the analytical methods differed significantly.

Vibrio parahaemolyticus in Long Island Oysters

1982 ◽  
Vol 45 (2) ◽  
pp. 150-151 ◽  
Author(s):  
ANTHONY A. TEPEDINO
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Long Island ◽  
Most Probable Number ◽  
Ileal Loop ◽  
Probable Number ◽  
Number Range

Twelve of 36 samples of Long Island oysters were found to contain Vibrio parahaemolyticus with a most probable number range of 3.6 to 23 organisms/g. Six of 10 isolates tested were weakly Kanagawa positive. None was pathogenic by the rabbit ileal loop test.

Effects of Flash Freezing, Followed by Frozen Storage, on Reducing Vibrio parahaemolyticus in Pacific Raw Oysters (Crassostrea gigas)

2009 ◽  
Vol 72 (1) ◽  
pp. 174-177 ◽  
Author(s):  
CHENGCHU LIU ◽  
JIANZHANG LU ◽  
YI-CHENG SU
Keyword(s):  
Crassostrea Gigas ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Frozen Storage ◽  
Most Probable Number ◽  
Freezing Process ◽  
Probable Number ◽  
Pacific Oysters ◽  
Subsequent Storage ◽  
Shellfish Sanitation

This study investigated the effects of flash freezing, followed by frozen storage, on reducing Vibrio parahaemolyticus in Pacific raw oysters. Raw Pacific oysters were inoculated with a five-strain cocktail of V. parahaemolyticus at a total level of approximately 3.5 × 105 most probable number (MPN) per gram. Inoculated oysters were subjected to an ultralow flash-freezing process (−95.5°C for 12 min) and stored at −10, −20, and −30°C for 6 months. Populations of V. parahaemolyticus in the oysters declined slightly by 0.22 log MPN/g after the freezing process. Subsequent storage of frozen oysters at −10, −20, and −30°C resulted in considerable reductions of V. parahaemolyticus in the oysters. Storing oysters at −10°C was more effective in inactivating V. parahaemolyticus than was storage at −20 or −30°C. Populations of V. parahaemolyticus in the oysters declined by 2.45, 1.71, and 1.45 log MPN/g after 1 month of storage at −10, −20, and −30°C, respectively, and continued to decline during the storage. The levels of V. parahaemolyticus in oysters were reduced by 4.55, 4.13, and 2.53 log MPN/g after 6 months of storage at −10, −20, and −30°C, respectively. Three process validations, each separated by 1 week and conducted according to the National Shellfish Sanitation Program's postharvest processing validation–verification interim guidance for Vibrio vulnificus and Vibrio parahaemolyticus, confirmed that a process of flash freezing, followed by storage at −21 ± 2°C for 5 months, was capable of achieving greater than 3.52-log (MPN/g) reductions of V. parahaemolyticus in half-shell Pacific oysters.

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.

Depuration of Oysters (Crassostrea gigas) Contaminated with Vibrio parahaemolyticus and Vibrio vulnificus with UV Light and Chlorinated Seawater

2012 ◽  
Vol 75 (8) ◽  
pp. 1501-1506 ◽  
Author(s):  
ROBERTA JULIANO RAMOS ◽  
MARÍLIA MIOTTO ◽  
FRANCISCO JOSÉ LAGREZE SQUELLA ◽  
ANDRÉIA CIROLINI ◽  
JAIME FERNANDO FERREIRA ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Uv Light ◽  
Control Treatment ◽  
Most Probable Number ◽  
Brazilian Coast ◽  
Uv Treatment ◽  
Probable Number ◽  
Postharvest Treatment ◽  
Small Producers

The efficacy of depuration using UV light and chlorinated seawater for decontaminating Vibrio parahaemolyticus and Vibrio vulnificus from oysters was investigated. Oysters were contaminated with a five-strain cocktail of V. parahaemolyticus or V. vulnificus to levels of 104 to 105 CFU ml−1 for bioaccumulation. The depuration was conducted in a closed system in which 350 liters of seawater was recirculated at a rate of 7 liters/min for 48 h at room temperature. Counts of V. parahaemolyticus or V. vulnificus were determined at 0, 6, 18, 24, and 48 h. Three treatments were conducted: T1, control treatment; T2, UV treatment; and T3, UV plus chlorine treatment. After 48 h of depuration of V. parahaemolyticus, T3 reduced the count by 3.1 log most probable number (MPN) g−1 and T2 reduced the count by 2.4 log MPN g−1, while T1 reduced the count by only 2.0 log MPN g−1. After 48 h of depuration of V. vulnificus, T2 and T3 were efficient, reducing the counts by 2.5 and 2.4 log MPN g−1, respectively, while T1 reduced the count by only 1.4 log MPN g−1. The UV light plus chlorine treatment was more efficient for controlling V. parahaemolyticus in oysters. Both UV light and UV light plus chlorine were efficient for V. vulnificus. The present study is the first report showing the efficacy of depuration systems for decontaminating V. parahaemolyticus and V. vulnificus in oysters cultivated on the Brazilian coast. This study provides information on processes that can contribute to controlling and preventing such microorganisms in oysters and could be used for effective postharvest treatment by restaurants and small producers of oysters on the coast of Brazil.

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.

Evaluation of the Compact Dry VP Method for Screening Raw Seafood for Total Vibrio parahaemolyticus

2009 ◽  
Vol 72 (1) ◽  
pp. 169-173 ◽  
Author(s):  
HIDEMASA KODAKA ◽  
HAJIME TERAMURA ◽  
SHINGO MIZUOCHI ◽  
MIKAKO SAITO ◽  
HIDEAKI MATSUOKA
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Cold Water ◽  
Correlation Coefficients ◽  
Water Soluble ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Different Types ◽  
Phosphate Buffered Saline ◽  
Vibrio Spp

Compact Dry VP (CDVP) is a ready-to-use method for enumerating Vibrio parahaemolyticus in food. The presterilized plates contain a culture medium comprising peptone, NaCl, bile salts, antibiotics, chromogenic substrates, and polysaccharide gum as a cold water–soluble gelling. After diluting raw seafood samples in a phosphate-buffered saline solution, a 1-ml aliquot was inoculated onto the center of the plate and allowed to diffuse by capillary action. Blue-green colonies forming on the plates were counted after 18 to 20 h of incubation at 35°C. A total of 85 V. parahaemolyticus strains (62 tdh+ strains and 23 tdh− strains) were studied for inclusivity, 81 (95.3 %) of which produced blue-green colonies. When 97 strains (14 strains of Vibrio spp., 33 strains of coliform bacteria, and 50 strains of noncoliform bacteria) were assessed for exclusivity, 10 strains of Vibrio spp. produced non–blue-green colonies, and 87 strains failed to grow. The CDVP and U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA-BAM) methods were compared with the use of four different types of raw seafood that were inoculated with four different V. parahaemolyticus strains. For raw tuna and oysters, the FDA-BAM colony lift method was used, whereas the FDA-BAM most-probable-number method was used for salmon and scallop. The linear correlation coefficients between the CDVP and FDA-BAM methods were 0.99 for fresh raw tuna, 0.95 for fresh raw oysters, 0.95 for frozen raw salmon, and 0.95 for frozen raw scallops. These results suggest that the CDVP method is useful for screening raw seafood for V. parahaemolyticus.

scholarly journals Evaluation of Two Direct Plating Methods Using Nonradioactive Probes for Enumeration of Vibrio parahaemolyticus in Oysters

2001 ◽  
Vol 67 (2) ◽  
pp. 721-724 ◽  
Author(s):  
J. A. Gooch ◽  
A. DePaola ◽  
C. A. Kaysner ◽  
D. L. Marshall
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Mobile Bay ◽  
Probable Number ◽  
Direct Plating ◽  
Hemolysin Gene ◽  
Highly Correlated ◽  
Species Specific ◽  
Labeled Probe ◽  
Zero Time

ABSTRACT Oysters (Crassostrea virginica) were collected monthly from May 1998 to April 1999 from Mobile Bay, Ala., and analyzed to determine Vibrio parahaemolyticus densities at zero time and after 5, 10, and 24 h of postharvest storage at 26°C. After 24 h of storage at 26°C, oysters were transferred to a refrigerator at 3°C and then analyzed 14 to 17 days later. TheV. parahaemolyticus numbers were determined by the most-probable-number procedure using alkaline phosphatase-labeled DNA probe VPAP, which targets the species-specific thermolabile hemolysin gene (tlh), to identify suspect isolates (MPN-VPAP procedure). Two direct plating methods, one using a VPAP probe (Direct-VPAP) and one using a digoxigenin-labeled probe (Direct-VPDig) to identify suspect colonies, were compared to the MPN-VPAP procedure. The results of the Direct-VPAP and Direct-VPDig techniques were highly correlated (r = 0.91), as were the results of the Direct-VPAP and MPN-VPAP procedures (r = 0.91). The correlation between the Direct-VPDig and MPN-VPAP results was 0.85. The two direct plating methods in which nonradioactive DNA probes were used were equivalent to the MPN-VPAP procedure for identification of totalV. parahaemolyticus, and they were more rapid and less labor-intensive.

Sign in / Sign up

Export Citation Format

Share Document