Density of Total and Pathogenic (tdh+) Vibrio parahaemolyticus in Atlantic and Gulf Coast Molluscan Shellfish at Harvest

2002 ◽  
Vol 65 (12) ◽  
pp. 1873-1880 ◽  
Author(s):  
DAVID W. COOK ◽  
JOHN C. BOWERS ◽  
ANGELO DePAOLA
Keyword(s):  
Water Temperature ◽  
Vibrio Parahaemolyticus ◽  
Gulf Coast ◽  
Limit Of Detection ◽  
Atlantic Coast ◽  
Direct Plating ◽  
The North ◽  
Pathogenic Vibrio ◽  
Thermostable Direct Hemolysin ◽  
State Changes

The densities of total and pathogenic Vibrio parahaemolyticus in 671 samples of molluscan shellfish harvested in 1999 and 2000 from 14 sites in seven Gulf and Atlantic coast states were determined at 2-week intervals over a period of 12 to 16 months in each state. Changes in V. parahaemolyticus densities in shellfish between harvest and sample analysis were minimized with time and temperature controls. Densities were measured by direct plating techniques, and gene probes were used for identification. Total and pathogenic V. parahaemolyticus organisms were identified with probes for the thermolabile direct hemolysin (tlh) gene and the thermostable direct hemolysin (tdh) gene, respectively. An enrichment procedure involving 25 g of shellfish was also used for the recovery of pathogenic V. parahaemolyticus. The densities of V. parahaemolyticus in shellfish from all harvest sites were positively correlated with water temperature. Shellfish from the Gulf Coast typically had higher densities of V. parahaemolyticus than did shellfish harvested from the North Atlantic or mid-Atlantic coast. Vibrio parahaemolyticus counts exceeded 1,000 CFU/g for only 5% of all samples. Pathogenic (tdh+) V. parahaemolyticus was detected in approximately 6% of all samples by both procedures, and 61.5% of populations in the positive samples from the direct plating procedure were at the lower limit of detection (10 CFU/g). The frequency of detection of pathogenic V. parahaemolyticus was significantly related to water temperature and to the density of total V. parahaemolyticus. The failure to detect pathogenic V. parahaemolyticus in shellfish more frequently was attributed to the low numbers and uneven distribution of the organism.

scholarly journals Assessment of Vibrio parahaemolyticus levels in oysters (Crassostrea virginica) and seawater in Delaware Bay in relation to environmental conditions and the prevalence of molecular markers to identify pathogenic Vibrio parahaemolyticus strains

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242229
Author(s):  
Esam Almuhaideb ◽  
Lathadevi K. Chintapenta ◽  
Amanda Abbott ◽  
Salina Parveen ◽  
Gulnihal Ozbay
Keyword(s):  
Water Temperature ◽  
Vibrio Parahaemolyticus ◽  
Environmental Parameters ◽  
Delaware Bay ◽  
Gene Markers ◽  
Toxic Activity ◽  
Pathogenic Vibrio ◽  
Thermostable Direct Hemolysin ◽  
Seawater Samples ◽  
Species Specific

This study identified Vibrio parahaemolyticus in oyster and seawater samples collected from Delaware Bay from June through October of 2016. Environmental parameters including water temperature, salinity, dissolved oxygen, pH, and chlorophyll a were measured per sampling event. Oysters homogenate and seawater samples were 10-fold serially diluted and directly plated on CHROMagarᵀᴹ Vibrio medium. Presumptive V. parahaemolyticus colonies were counted and at least 20% of these colonies were selected for molecular chracterization. V. parahaemolyticus isolates (n = 165) were screened for the presence of the species-specific thermolabile hemolysin (tlh) gene, the pathogenic thermostable direct hemolysin (tdh)/ thermostable related hemolysin (trh) genes, the regulatory transmembrane DNA-binding gene (toxR), and V. parahaemolyticus metalloprotease (vpm) gene using a conventional PCR. The highest mean levels of the presumptive V. parahaemolyticus were 9.63×103 CFU/g and 1.85×103 CFU/mL in the oyster and seawater samples, respectively, during the month of July. V. parahaemolyticus levels in oyster and seawater samples were significantly positively correlated with water temperature. Of the 165 isolates, 137 (83%), 110 (66.7%), and 108 (65%) were tlh+, vpm+, and toxR+, respectively. Among the V. parahaemolyticus (tlh+) isolates, 7 (5.1%) and 15 (10.9%) were tdh+ and trh+, respectively, and 24 (17.5%), only oyster isolates, were positive for both genes. Potential pathogenic strains that possessed tdh and/or trh were notably higher in oyster (39%) than seawater (15.6%) isolates. The occurrence of total V. parahaemolyticus (tlh+) was not necessarily proportional to the potential pathogenic V. parahaemolyticus. Co-occurrence of the five genetic markers were observed only among oyster isolates. The co-occurrence of the gene markers showed a relatedness potential of tdh occurrence with vpm. We believe exploring the role of V. parahaemolyticus metalloprotease and whether it is involved in the toxic activity of the thermostable direct hemolysin (TDH) protein can be of significance. The outcomes of this study will provide some foundation for future studies regarding pathogenic Vibrio dynamics in relation to environmental quality.

scholarly journals Longitudinal Study of Total and Pathogenic Vibrio parahaemolyticus (tdh+ and/or trh+) in Two Natural Extraction Areas of Mytilus chilensis in Southern Chile

2021 ◽  
Vol 12 ◽  
Author(s):  
Cristina Bacian ◽  
Cristobal Verdugo ◽  
Katherine García ◽  
Josu Perez-Larruscain ◽  
Ignacio de Blas ◽  
...  
Keyword(s):  
Water Temperature ◽  
Vibrio Parahaemolyticus ◽  
River Estuary ◽  
Environmental Parameters ◽  
Economic Losses ◽  
Pcr Analysis ◽  
Potential Hazard ◽  
Detection Rates ◽  
Pathogenic Vibrio ◽  
Interaction Factor

Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh+ was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems.

Comparative evaluation of a chromogenic agar medium – PCR protocol with a conventional method for isolation of Vibrio parahaemolyticus strains from environmental and clinical samples

2011 ◽  
Vol 57 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Adrian Canizalez-Roman ◽  
Héctor Flores-Villaseñor ◽  
Jorge Zazueta-Beltran ◽  
Secundino Muro-Amador ◽  
Nidia León-Sicairos
Keyword(s):  
Conventional Method ◽  
Vibrio Parahaemolyticus ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Pathogenic Vibrio ◽  
Food Borne ◽  
Thermostable Direct Hemolysin ◽  
Chromogenic Agar ◽  
Northwestern Mexico ◽  
Low Sensitivity

Screening for pathogenic Vibrio parahaemolyticus has become routine in certain areas associated with food-borne outbreaks. This study is an evaluation of the CHROMagar Vibrio (CV) medium – PCR protocol and the conventional method (TCBS (thiosulfate – citrate – bile salts – sucrose) agar plus biochemical and Wagatsuma agar tests) for detection of V. parahaemolyticus in shrimp, water, sediment, and stool samples collected for biosurveillance in an endemic area of northwestern Mexico. A total of 131 environmental and clinical samples were evaluated. The CV medium – PCR protocol showed a significantly improved ability (P < 0.05) to isolate and detect V. parahaemolyticus, identifying isolates of this bacteria missed by the conventional method. Although some other bacteria, distinct from pathogenic V. parahaemolyticus, produced violet colonies similar to that of V. parahaemolyticus on CV medium, we were able to detect a superior number of samples of V. parahaemolyticus with the CV medium – PCR protocol than with the conventional method. The Kanagawa phenomenon is routinely determined on Wagatsuma agar for the diagnosis of V. parahaemolyticus (pathogenic) positive for thermostable direct hemolysin (TDH) in developing countries. In our results, Wagatsuma agar showed low sensitivity (65.4% at 24 h and 75.6% at 48 h) and specificity (52.4% at 48 h) for identifying V. parahaemolyticus positive for TDH. Overall, our data support the use of the CV medium – PCR protocol in place of the conventional method (TCBS – biochemical tests – Wagatsuma agar) for detection of pathogenic V. parahaemolyticus, both in terms of effectiveness and cost efficiency.

scholarly journals Seasonal Abundance of Total and Pathogenic Vibrio parahaemolyticus in Alabama Oysters

2003 ◽  
Vol 69 (3) ◽  
pp. 1521-1526 ◽  
Author(s):  
Angelo DePaola ◽  
Jessica L. Nordstrom ◽  
John C. Bowers ◽  
Joy G. Wells ◽  
David W. Cook
Keyword(s):  
United States ◽  
Vibrio Parahaemolyticus ◽  
Inverse Relationship ◽  
The United States ◽  
Seasonal Abundance ◽  
Focused Attention ◽  
Mobile Bay ◽  
Pathogenic Vibrio ◽  
Thermostable Direct Hemolysin ◽  
Efficient Screening

ABSTRACT Recent Vibrio parahaemolyticus outbreaks associated with consumption of raw shellfish in the United States focused attention on the occurrence of this organism in shellfish. From March 1999 through September 2000, paired oyster samples were collected biweekly from two shellfish-growing areas in Mobile Bay, Ala. The presence and densities of V. parahaemolyticus were determined by using DNA probes targeting the thermolabile hemolysin (tlh) and thermostable direct hemolysin (tdh) genes for confirmation of total and pathogenic V. parahaemolyticus, respectively. V. parahaemolyticus was detected in all samples with densities ranging from <10 to 12,000 g−1. Higher V. parahaemolyticus densities were associated with higher water temperatures. Pathogenic strains were detected in 34 (21.8%) of 156 samples by direct plating or enrichment. Forty-six of 6,018 and 31 of 6,992 V. parahaemolyticus isolates from enrichments and direct plates, respectively, hybridized with the tdh probe. There was an apparent inverse relationship between water temperature and the prevalence of pathogenic strains. Pathogenic strains were of diverse serotypes, and 97% produced urease and possessed a tdh-related hemolysin (trh) gene. The O3:K6 serotype associated with pandemic spread and recent outbreaks in the United States was not detected. The efficient screening of numerous isolates by colony lift and DNA probe procedures may account for the higher prevalence of samples with tdh + V. parahaemolyticus than previously reported.

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.

scholarly journals Tropical Cyclones and Drought Amelioration in the Gulf and Southeastern Coastal United States

2013 ◽  
Vol 26 (21) ◽  
pp. 8440-8452 ◽  
Author(s):  
Justin T. Maxwell ◽  
Jason T. Ortegren ◽  
Paul A. Knapp ◽  
Peter T. Soulé
Keyword(s):  
United States ◽  
Tropical Cyclones ◽  
North Atlantic ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
Southeastern United States ◽  
Atlantic Multidecadal Oscillation ◽  
The North ◽  
Ocean Atmosphere ◽  
Drought Conditions

Abstract Precipitation from land-falling tropical cyclones (TCs) has a significant hydroclimatic influence in the southeastern United States, particularly during drought years. The frequency with which TCs ended drought conditions was examined for southeastern coastal states from Texas to North Carolina during 1895–2011. The region was divided into the Gulf Coast states (GCS) and the southeastern Atlantic coast states (ACS). The spatiotemporal patterns of tropical cyclone drought busters (TCDBs) were analyzed. Larger-scale ocean–atmosphere influences on TCDBs were examined using chi-squared analysis. The ACS experienced TCDBs more frequently and farther inland compared to the GCS. The number of TCDBs has significantly increased with time in the ACS. TCDBs numbers in the GCS did not exhibit significant increases, but the area alleviated of drought conditions increased significantly in the last 117 years. The dominant larger-scale ocean–atmosphere forcing of TCDBs was a combination of a warm Atlantic Ocean [positive Atlantic multidecadal oscillation index (AMO+)] and weak westerlies [negative North Atlantic Oscillation index (NAO−)]. AMO+ leads to an increase in the number of TCs throughout the North Atlantic basin, and NAO− increases the likelihood of TC landfall by controlling the steering of TCs toward the southeastern United States.

Occurrence of Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus in the Aquacultural Environments of Taiwan

2015 ◽  
Vol 78 (5) ◽  
pp. 969-976 ◽  
Author(s):  
YAO HSIEN TEY ◽  
KOA-JEN JONG ◽  
SHIN-YUAN FEN ◽  
HIN-CHUNG WONG
Keyword(s):  
Water Temperature ◽  
Vibrio Cholerae ◽  
Vibrio Parahaemolyticus ◽  
Membrane Filtration ◽  
Vibrio Vulnificus ◽  
Pearson Correlation ◽  
Isolation Frequency ◽  
Freshwater Ponds ◽  
Pathogenic Vibrio ◽  
Southern Taiwan

The occurrence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern Taiwan was examined by the membrane filtration and colony hybridization method. The halophilic V. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log CFU/g. V. cholerae was found in both the seawater and freshwater ponds but preferentially in freshwater ponds, with a frequency of 72.2% and a mean density of 1.65 log CFU/g. V. vulnificus was identified mainly in seawater ponds, with an isolation frequency of 27.8%. The density of V. parahaemolyticus in seawater ponds was positively related to water temperature (Pearson correlation coefficient, r = 0.555) and negatively related to salinity (r = −0.333). The density of V. cholerae in all six ponds was positively related to water temperature (r = 0.342) and negatively related to salinity (r = −0.432). Two putatively pathogenic tdh+ V. parahaemolyticus isolates (1.4% of the samples) and no ctx+ V. cholerae isolates were identified. The experimental results may facilitate assessments of the risk posed by these pathogenic Vibrio species in Taiwan, where aquaculture provides a large part of the seafood supply.

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 &lt; 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.

Environmental parameters influence on the dynamics of total and pathogenic Vibrio parahaemolyticus densities in Crassostrea virginica harvested from Mexico’s Gulf coast

2015 ◽  
Vol 91 (1) ◽  
pp. 317-329 ◽  
Author(s):  
Karla M. López-Hernández ◽  
Violeta T. Pardío-Sedas ◽  
Leonardo Lizárraga-Partida ◽  
José de J. Williams ◽  
David Martínez-Herrera ◽  
...  
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Parahaemolyticus ◽  
Gulf Coast ◽  
Environmental Parameters ◽  
Pathogenic Vibrio
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