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

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

2003 ◽  
Vol 66 (12) ◽  
pp. 2276-2282 ◽  
Author(s):  
DAVID W. COOK

Multiple strains of Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio cholerae non-O1 were tested in phosphate-buffered saline for their sensitivity to high-pressure processing (HPP). Variability in sensitivity among strains was observed for all species; this variability decreased at higher pressures. V. vulnificus was the species that was most sensitive to treatment at 200 MPa (decimal reduction time [D] = 26 s), and V. cholerae was the species that was most resistant to treatment at 200 MPa (D = 149 s). The O3:K6 serotype of V. parahaemolyticus was more resistant to pressure than other serotypes of V. parahaemolyticus were. The results of studies involving V. vulnificus naturally occurring in oysters revealed that a pressure treatment of 250 MPa for 120 s achieved a >5-log reduction in the levels of this bacterium. V. parahaemolyticus serotype O3:K6 in oysters required a pressure of 300 MPa for 180 s for a comparable 5-log reduction. When properly applied, HPP can be effective in improving the safety of shellfish with respect to Vibrio spp.


2008 ◽  
Vol 71 (7) ◽  
pp. 1475-1480 ◽  
Author(s):  
KEVIN MELODY ◽  
RESHANI SENEVIRATHNE ◽  
MARLENE JANES ◽  
LEE ANN JAYKUS ◽  
JOHN SUPAN

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.


2005 ◽  
Vol 68 (7) ◽  
pp. 1454-1456 ◽  
Author(s):  
YI-CHENG SU ◽  
JINGYUN DUAN ◽  
WEN-HSIN WU

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.


2018 ◽  
Vol 81 (4) ◽  
pp. 593-597 ◽  
Author(s):  
THI THU TRA VU ◽  
THOMAS ALTER ◽  
STEPHAN HUEHN

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.


2016 ◽  
Vol 83 (2) ◽  
Author(s):  
B. A. Froelich ◽  
B. Phippen ◽  
P. Fowler ◽  
R. T. Noble ◽  
J. D. Oliver

ABSTRACT Filter feeding shellfish can concentrate pathogenic bacteria, including Vibrio vulnificus and Vibrio parahaemolyticus, as much as 100-fold from the overlying water. These shellfish, especially clams and oysters, are often consumed raw, providing a route of entry for concentrated doses of pathogenic bacteria into the human body. The numbers of foodborne infections with these microbes are increasing, and a better understanding of the conditions that might trigger elevated concentrations of these bacteria in seafood is needed. In addition, if bacterial concentrations in water are correlated with those in shellfish, then sampling regimens could be simplified, as water samples can be more rapidly and easily obtained. After sampling of oysters and clams, either simultaneously or separately, for over 2 years, it was concluded that while Vibrio concentrations in oysters and water were related, this was not the case for levels in clams and water. When clams and oysters were collected simultaneously from the same site, the clams were found to have lower Vibrio levels than the oysters. Furthermore, the environmental parameters that were correlated with levels of Vibrio spp. in oysters and water were found to be quite different from those that were correlated with levels of Vibrio spp. in clams. IMPORTANCE This study shows that clams are a potential source of infection in North Carolina, especially for V. parahaemolyticus. These findings also highlight the need for clam-specific environmental research to develop accurate Vibrio abundance models and to broaden the ecological understanding of clam-Vibrio interactions. This is especially relevant as foodborne Vibrio infections from clams are being reported.


1970 ◽  
Vol 5 (2) ◽  
pp. 16-17
Author(s):  
Mickey Vincent ◽  
Lawrance Tuah ◽  
Christy Chan Sien Wei ◽  
Lesley Maurice Bilung ◽  
Kasing Apun

The present study was conducted to investigate the occurrence of Vibrio spp. from selected rivers in Kuching,Sarawak (Malaysia) using Multiplex Polymerase Chain Reaction (m-PCR). During the 6-month study period,19 samples were collected monthly from 7 rivers, followed by simultaneous detection of three Vibrio spp.,Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, in a single tube PCR reaction. Three sets ofprimers targeting the thermolabile (tl), outer membrane protein (ompW) and hemolysin/cytolysin genes(vulCulsl) of V. parahaemolyticus, V. cholerae and V. vulnificus, respectively, were used. The results indicatedthat V. parahaemolyticus was the predominant species, occurring approximately 60.9% throughout thesampling period, followed by V. cholerae (23.1%) and V. vulnificus (16.0%). The months of July andDecember were found to be the months where all three Vibrio spp. were found to be at higher frequencies inthe river samples. Results analyzed also indicated that the rivers with the highest prevalence of the three Vibriospp. were Tambak Sejingkat, followed by Sungai Jernang and Sungai Tabuan. We conclude that m-PCR is apowerful and useful tool for the rapid and simultaneous detection of V. parahaemolyticus, V. cholerae and V.vulnificus from the riverine environments without the need for isolation and culturing. Furthermore, thismethod is highly specific, and could be applied in diagnostic laboratories for larger scale epidemiologicalinvestigations of Vibrio spp.


Author(s):  
I. M. Nityaga ◽  
◽  
B. V. Usha ◽  
O. V. Prostova ◽  
◽  
...  

Analysis of microbiological safety of fish and fish products involves the assessment of the presence of a number of pathogenic bacteria in these products. One of these important bacteria is Vibrio parahaemolyticus – a gram-negative halophilic bacilus found in warm sea waters. The aim of this work was to verify the method of isolation of Vibrio parahaemolyticus from marine fish and fish products, as well as to study the presence of Vibrio samples of fish products from large retail chains. Verification of the method of detection of parahemolytic Vibrio from fish and fish products was carried out in accordance with GOST ISO/TS 21872-2-2013 "Microbiology of food and animal feed. Horizontal method for detection of potentially enteropathogenic Vibrio spp. Part 2. "Detection of bacteria species differs from Vibrio parahaemolyticus and Vibrio cholerae". As a result of the performed studies, the reliability of this method of detection of Vibrio parahaemolyticus on artificially contaminated samples was established. During monitoring fish products, parahemolytic vibrio was not detected.


2015 ◽  
Vol 78 (11) ◽  
pp. 2089-2092 ◽  
Author(s):  
L. SPERLING ◽  
T. ALTER ◽  
S. HUEHN

The aim of this study was to investigate the prevalence of Vibrio spp. in shrimp at retail and in shrimp farms in Ecuador and to determine the antimicrobial agent resistance patterns of farm isolates. The presence of genes linked to early mortality syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) also was evaluated. Vibrio spp. were isolated from retail shrimps in Cuenca, Ecuador, and farm shrimps originating from provinces El Oro and Guayas, Ecuador. A total of 229 shrimp samples were collected, of which 71 originated from retail markets in Cuenca and 158 came from shrimp farms. Overall, 219 (95.6%) samples tested positive for Vibrio spp. Vibrio parahaemolyticus (80.8%) was the most common species detected, followed by Vibrio alginolyticus (50.2%), Vibrio cholerae (11.3%), and Vibrio vulnificus (3.5%). None of the V. parahaemolyticus isolates carried the virulence-associated tdh and trh genes. In V. parahaemolyticus shrimp farm isolates, high resistance was found to ampicillin (92.2%), and intermediate resistance was found to tetracycline (51.3%) and amikacin (22.1%). Of the V. parahaemolyticus strains, 68 were resistant to at least three antimicrobial agents, and 2 were resistant to seven antimicrobial agents simultaneously. Up to 18 resistant isolates were found for V. alginolyticus, whereas V. vulnificus and V. cholerae isolates were more susceptible. None of the V. parahaemolyticus isolates carried the EMS-AHPND plasmid. The results of this study revealed the ubiquitous occurrence of Vibrio spp. in shrimps at retail and on shrimp farms in Ecuador.


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