EFFECT OF STORAGE AT 5 C ON SURVIVAL OF VIBRIO PARAHAEMOLYTICUS IN PROCESSED MARYLAND OYSTERS (CRASSOSTREA VIRGINICA)1

1974 ◽  
Vol 37 (2) ◽  
pp. 74-77 ◽  
Author(s):  
Lydia J. Goatcher ◽  
Sharon E. Engler ◽  
David C. Wagner ◽  
Dennis C. Westhoff
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Parahaemolyticus Strain ◽  
Ph Change ◽  
Inoculum Level ◽  
Probable Number ◽  
Direct Plating ◽  
Viable Cells ◽  
Plating Method

Freshly processed Maryland oysters (Crassostrea virginica) were inoculated with various levels of Vibrio parahaemolyticus Strain 3525 (03:K30), Kanagawa negative, and Strain 8700 (04:K11), Kanagawa positive. Inoculated oysters were stored at 5 C for up to 13 days and numbers of viable cells determined at regular intervals by both a direct plating, method and a most probable number (MPN) method. The number of cells detected was dependent on strain, inoculum level, and method of enumeration. In general, the direct plating method was unreliable and results varied according to plating medium used. At an inoculum level of 106 cells/g, viable cells of Strain 3525 and Strain 8700 were not detected by the direct plating method after 3 and 5 days of storage, respectively, while by the MPN method low numbers of Strain 3525 and Strain 8700 were still detected after 7 and 13 days of storage, respectively. At inoculum levels of 104 and 102 cells/g, the direct plating method did not accurately enumerate viable cells. Neither strain was detected by the MPN method following 5 days of storage at these inoculum levels. Loss of viability of both strains occurred most rapidly within the first 24 h and in some instances was as great as 3 log cycles. In general, higher levels of survivors of Strain 8700 than Strain 3525 were noted throughout the study. The pH change of oysters during storage was slight and could not account for the loss of viability of either strain.

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.

The Anderson–Baird-Parker direct plating method versus the most probable number procedure for enumerating Escherichia coli in meats

1981 ◽  
Vol 27 (1) ◽  
pp. 147-149 ◽  
Author(s):  
M. K. Rayman ◽  
B. Aris
Keyword(s):  
Escherichia Coli ◽  
North American ◽  
Most Probable Number ◽  
Probable Number ◽  
Direct Plating ◽  
E Coli ◽  
Membrane Filters ◽  
The North ◽  
Plating Method

Comparison of the Anderson–Baird-Parker direct plating method (DP) and the North American most probable number procedure (MPN) for enumerating Escherichia coli in frozen meats revealed that the DP method is more precise and yields higher counts of E. coli than the MPN procedure. Any of three brands of membrane filters tested was suitable for use in the DP method.

ICMSF methods studies. XIII. An international comparative study of the MPN procedure and the Anderson–Baird–Parker direct plating method for the enumeration of Escherichia coli biotype I in raw meats

1979 ◽  
Vol 25 (11) ◽  
pp. 1321-1327 ◽  
Author(s):  
M. K. Rayman ◽  
G. A. Jarvis ◽  
C. M. Davidson ◽  
S. Long ◽  
J. M. Allen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Most Probable Number ◽  
Probable Number ◽  
Direct Plating ◽  
E Coli ◽  
Plating Method ◽  
International Comparative ◽  
Lower Variability ◽  
Raw Meats

The most probable number (MPN) and a direct membrane-plating (DP) method were compared for enumeration of Escherichia coli biotype I in raw meats by 11 laboratories. The DP method yielded higher counts of E. coli than the MPN method for frozen samples but neither method consistently gave higher counts for non-frozen samples. The DP method was less variable and gave a higher rate of detection of low numbers of E. coli in frozen samples. Despite the inability of the DP method to enumerate E. coli biotype II and intermediate types, which comprise only 3–5% of the Escherichia strains (Ewing 1972), the method is preferable to the MPN method for enumerating E. coli in raw meats because of its lower variability, better recovery from frozen samples, rapidity, decreased requirement for media, and decreased costs for analysts' time.

A Direct Plating Method for Estimating Populations of Escherichia coli O157 in Bovine Manure and Manure-Based Materials†

2008 ◽  
Vol 71 (11) ◽  
pp. 2233-2238 ◽  
Author(s):  
ELAINE D. BERRY ◽  
JAMES E. WELLS
Keyword(s):  
Escherichia Coli ◽  
Soil Amendments ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Surface Material ◽  
Potassium Tellurite ◽  
Probable Number ◽  
Direct Plating ◽  
E Coli ◽  
Plating Method

Escherichia coli O157:H7 outbreaks associated with produce consumption have brought attention to livestock manures and manure-based soil amendments as potential sources of pathogens for the contamination of these crops. Procedures for enumeration of E. coli O157:H7 are needed to assess the risks of transmission from these manures and their by-products. A direct plating method employing spiral plating onto CHROMagar O157 was investigated for enumeration of E. coli O157:H7 in feedlot surface material, aged bovine manure, bovine manure compost, and manure-amended soil. In studies utilizing samples spiked with a five-strain cocktail of E. coli O157:H7 at levels ranging from 102 to 105 CFU/g of sample, there were strong correlations between the observed and predicted levels of this pathogen. Although the addition of 2.5 mg/liter potassium tellurite and 5 mg/liter novobiocin made the medium more restrictive, these amendments enhanced the ability to identify and enumerate E. coli O157:H7 in feedlot surface material, which contained a higher proportion of fresh feces than did the other three sample types and therefore higher levels of interfering bacterial microflora. The spiral plating method was further assessed to determine its ability to enumerate E. coli O157:H7 in naturally contaminated feedlot surface material. Comparison of E. coli O157:H7 counts in feedlot surface material obtained by the spiral plating method and a most probable number technique were well correlated. We conclude that direct spiral plating onto CHROMagar O157 is effective for estimating E. coli O157: H7 levels in a variety of manures and manure-containing sample types to a lower detection limit of 200 CFU/g. The method has application for determining E. coli O157:H7 concentrations in manures and composts before their sale and use as soil amendments and for measuring the effectiveness of manure treatment processes to reduce or inactivate this pathogen.

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.

Comparative Validity of Members of the Total Coliform and Fecal Coliform Groups for Indicating the Presence of Salmonella in the Eastern Oyster, Crassostrea virginica

1975 ◽  
Vol 38 (8) ◽  
pp. 453-456 ◽  
Author(s):  
W. B. ANDREWS ◽  
C. D. DIGGS ◽  
M. W. PRESNELL ◽  
J. J. MIESCIER ◽  
C. R. WILSON ◽  
...  
Keyword(s):  
Crassostrea Virginica ◽  
Fecal Coliform ◽  
Eastern Oyster ◽  
Progressive Increase ◽  
Total Coliform ◽  
Most Probable Number ◽  
Overlying Water ◽  
Probable Number ◽  
Salmonella Serotypes ◽  
Area Standard

During a 24-month survey, 539 samples each of the Eastern oyster, Crassostrea virginica, and the overlying water were collected to determine the relation of most probable number (MPN) of the total and fecal coliform groups in shellfish and water to the presence of Salmonella in the shellfish themselves. Occurrence of Salmonella in the shellfish more closely paralleled a progressive increase in the fecal coliform MPN as compared to the total coliform MPN in the water and shellfish meat. The percentage of Salmonella-positive shellfish samples was somewhat higher in oysters harvested from waters conforming to the present bacteriological approved growing area standard of ≤70 total coliforms per 100 ml water as compared to these same waters meeting a recently proposed fecal coliform standard of ≤14 organisms per 100 ml. In no instance was Salmonella detected in oysters from growing areas officially approved for harvesting on the basis of both a bacteriological and sanitary survey. Of a variety of enrichment broths and plating media used for recovery of Salmonella from oysters, direct enrichment in tetrathionate broth with added brilliant green followed by streaking on bismuth sulfite agar was the most productive combination of media for recovering a large variety of Salmonella serotypes.

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.

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