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Lydon KA, Kinsey T, Le C, Gulig PA, Jones JL. Biochemical and Virulence Characterization of Vibrio vulnificus Isolates From Clinical and Environmental Sources. Front Cell Infect Microbiol 2021; 11:637019. [PMID: 33718284 PMCID: PMC7952748 DOI: 10.3389/fcimb.2021.637019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/19/2021] [Indexed: 11/25/2022] Open
Abstract
Vibrio vulnificus is a deadly human pathogen for which infections occur via seafood consumption (foodborne) or direct contact with wounds. Virulence is not fully characterized for this organism; however, there is evidence of biochemical and genotypic correlations with virulence potential. In this study, biochemical profiles and virulence genotype, based on 16S rRNA gene (rrn) and virulence correlated gene (vcg) types, were determined for 30 clinical and 39 oyster isolates. Oyster isolates were more biochemically diverse than the clinical isolates, with four of the 20 tests producing variable (defined as 20–80% of isolates) results. Whereas, for clinical isolates only mannitol fermentation, which has previously been associated with virulence potential, varied among the isolates. Nearly half (43%) of clinical isolates were the more virulent genotype (rrnB/vcgC); this trend was consistent when only looking at clinical isolates from blood. The majority (64%) of oyster isolates were the less virulent genotype (rrnA or AB/vcgE). These data were used to select a sub-set of 27 isolates for virulence testing with a subcutaneously inoculated, iron-dextran treated mouse model. Based on the mouse model data, 11 isolates were non-lethal, whereas 16 isolates were lethal, indicating a potential for human infection. Within the non-lethal group there were eight oyster and three clinical isolates. Six of the non-lethal isolates were the less virulent genotype (rrnA/vcgE or rrnAB/vcgE) and two were rrnB/vcgC with the remaining two of mixed genotype (rrnAB/vcgC and rrnB/vcgE). Of the lethal isolates, five were oysters and 11 were clinical. Eight of the lethal isolates were the less virulent genotype and seven the more virulent genotype, with the remaining isolate a mixed genotype (rrnA/vcgC). A discordance between virulence genotype and individual mouse virulence parameters (liver infection, skin infection, skin lesion score, and body temperature) was observed; the variable most strongly associated with mouse virulence parameters was season (warm or cold conditions at time of strain isolation), with more virulent strains isolated from cold conditions. These results indicate that biochemical profiles and genotype are not significantly associated with virulence potential, as determined by a mouse model. However, a relationship with virulence potential and seasonality was observed.
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Affiliation(s)
- Keri A Lydon
- Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, U.S. Food and Drug Administration, Dauphin Island, AL, United States
| | - Thomas Kinsey
- Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, U.S. Food and Drug Administration, Dauphin Island, AL, United States
| | - Chinh Le
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
| | - Paul A Gulig
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
| | - Jessica L Jones
- Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, U.S. Food and Drug Administration, Dauphin Island, AL, United States
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D’Souza C, Prithvisagar KS, Deekshit VK, Karunasagar I, Karunasagar I, Kumar BK. Exploring the Pathogenic Potential of Vibrio vulnificus Isolated from Seafood Harvested along the Mangaluru Coast, India. Microorganisms 2020; 8:microorganisms8070999. [PMID: 32635463 PMCID: PMC7409051 DOI: 10.3390/microorganisms8070999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/10/2020] [Accepted: 05/21/2020] [Indexed: 12/19/2022] Open
Abstract
It has been observed that not all strains of Vibrio vulnificus are virulent. Determining the virulence of strains that are frequently present in seafood is of significance for ensuring seafood safety. This study is an attempt to predict the virulence of seafood-borne V. vulnificus isolated along the Mangaluru Coast, India. The isolates tested possessed a vcgC gene sequence with high similarity to that in the clinical strain. Transcriptional analysis of core virulence genes in seafood isolate E4010 showed the phenomenon of contact-mediated expression of rtxA1 which correlated well with the actin disintegration and cytotoxicity. These results suggest that the seafood isolates tested in this study possess a functional RtxA1 which could help in initiating the infection. However, other putative virulence genes such as vvpE encoding an extracellular protease, vvhA encoding hemolysin, flp encoding tad pilin and ompU encoding fibronectin-binding protein were also constitutively expressed. Virulence-associated attributes such as cytotoxicity and adherence matched the response of the clinical strain (p > 0.05). On the other hand, the environmental strains showed higher serum sensitivity compared with the clinical strain. These findings show that the part of virulence attributes required for the disease process might be intact in these isolates.
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Affiliation(s)
- Caroline D’Souza
- Division of Infectious Diseases, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Deralakatte, Mangalore 575018, India; (C.D.); (K.S.P.); (V.K.D.); (I.K.)
| | - Kattapuni Suresh Prithvisagar
- Division of Infectious Diseases, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Deralakatte, Mangalore 575018, India; (C.D.); (K.S.P.); (V.K.D.); (I.K.)
| | - Vijay Kumar Deekshit
- Division of Infectious Diseases, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Deralakatte, Mangalore 575018, India; (C.D.); (K.S.P.); (V.K.D.); (I.K.)
| | - Indrani Karunasagar
- Division of Infectious Diseases, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Deralakatte, Mangalore 575018, India; (C.D.); (K.S.P.); (V.K.D.); (I.K.)
| | - Iddya Karunasagar
- Nitte (Deemed to be University), University Enclave, Medical Sciences Complex, Deralakatte, Mangaluru 575018, India;
| | - Ballamoole Krishna Kumar
- Division of Infectious Diseases, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Deralakatte, Mangalore 575018, India; (C.D.); (K.S.P.); (V.K.D.); (I.K.)
- Correspondence: ; Tel.: +91-824-220-4292 (ext. 201)
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3
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An improved plasmid size standard, 39R861+. Plasmid 2019; 102:6-9. [DOI: 10.1016/j.plasmid.2019.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 11/23/2022]
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4
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Elmahdi S, DaSilva LV, Parveen S. Antibiotic resistance of Vibrio parahaemolyticus and Vibrio vulnificus in various countries: A review. Food Microbiol 2016; 57:128-34. [DOI: 10.1016/j.fm.2016.02.008] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 02/15/2016] [Accepted: 02/19/2016] [Indexed: 02/06/2023]
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5
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Abstract
Vibrio vulnificus, carrying a 50% fatality rate, is the most deadly of the foodborne pathogens. It occurs in estuarine and coastal waters and it is found in especially high numbers in oysters and other molluscan shellfish. The biology of V. vulnificus, including its ecology, pathogenesis, and molecular genetics, has been described in numerous reviews. This article provides a brief summary of some of the key aspects of this important human pathogen, including information on biotypes and genotypes, virulence factors, risk factor requirements and the role of iron in disease, association with oysters, geographic distribution, importance of salinity and water temperature, increasing incidence associated with global warming. This article includes some of our findings as presented at the "Vibrios in the Environment 2010" conference held in Biloxi, MS.
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6
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Abstract
Background Vibrio parahaemolyticus is a common pathogen infecting humans and marine animals; this pathogen has become a major concern of marine food products and trade. In this study, V. parahaemolyticus isolated from sewage was exposed to different culture conditions and analyzed by isobaric tag for relative and absolute quantitation (iTRAQ) based reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique. Our goal is to gain further insights into the proteomics of V. parahaemolyticus, particularly differentially expressed proteins closely correlated with growth conditions and pathogenicity associated proteins. Results In this study, a total of 2,717 proteins including numerous membrane proteins were significantly identified, and 616 proteins displayed significant differential expression under different conditions. Of them, 12 proteins mainly participating in metabolism showed the most elastic expression differentiation between different culture conditions. Some membrane proteins such as type I secretion outer membrane protein, TolC, lipoprotein, efflux system proteins iron-regulated protein A and putaive Fe-regulated protein B, ferric siderophore receptor homolog and several V. parahaemolyticus virulence-associated proteins were differentially regulated under different conditions. Some differentially regulated proteins were analyzed and confirmed at gene expression level by quantitative real time polymerase chain reaction (qRT-PCR). Conclusions Proteomics analysis results revealed the characteristics of V. parahaemolyticus proteome expression, provided some promising biomarkers related with growth conditions, the results likely advance insights into the mechanism involved in the response of V. parahaemolyticus to different conditions. Some virulence-associated proteins were discovered to be differentially expressed under different conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12953-015-0075-4) contains supplementary material, which is available to authorized users.
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Deng K, Wu X, Fuentes C, Su YC, Welti-Chanes J, Paredes-Sabja D, Torres JA. Analysis of Vibrio vulnificus Infection Risk When Consuming Depurated Raw Oysters. J Food Prot 2015; 78:1113-8. [PMID: 26038900 DOI: 10.4315/0362-028x.jfp-14-421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A beta Poisson dose-response model for Vibrio vulnificus food poisoning cases leading to septicemia was used to evaluate the effect of depuration at 15 °C on the estimated health risk associated with raw oyster consumption. Statistical variability sources included V. vulnificus level at harvest, time and temperature during harvest and transportation to processing plants, decimal reductions (SV) observed during experimental circulation depuration treatments, refrigerated storage time before consumption, oyster size, and number of oysters per consumption event. Although reaching nondetectable V. vulnificus levels (<30 most probable number per gram) throughout the year and a 3.52 SV were estimated not possible at the 95% confidence level, depuration for 1, 2, 3, and 4 days would reduce the warm season (June through September) risk from 2,669 cases to 558, 93, 38, and 47 cases per 100 million consumption events, respectively. At the 95% confidence level, 47 and 16 h of depuration would reduce the warm and transition season (April through May and October through November) risk, respectively, to 100 cases per 100 million consumption events, which is assumed to be an acceptable risk; 1 case per 100 million events would be the risk when consuming untreated raw oysters in the cold season (December through March).
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Affiliation(s)
- Kai Deng
- Food Process Engineering Group, Department of Food Science and Technology, Oregon State University, Corvallis, Oregon 97331, USA; Laboratorio de Mecanismos de Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile
| | - Xulei Wu
- Seafood Research and Education Center, Oregon State University, Astoria, Oregon 97103, USA
| | - Claudio Fuentes
- Department of Statistics, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
| | - Yi-Cheng Su
- Seafood Research and Education Center, Oregon State University, Astoria, Oregon 97103, USA
| | - Jorge Welti-Chanes
- Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Av. Eugenio Garza Sada 2501 Sur, Colonia Tecnológico, 64849 Monterrey, Nuevo León, México
| | - Daniel Paredes-Sabja
- Laboratorio de Mecanismos de Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile; Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA.
| | - J Antonio Torres
- Food Process Engineering Group, Department of Food Science and Technology, Oregon State University, Corvallis, Oregon 97331, USA.
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Monte Carlo analysis of the product handling and high-pressure treatment effects on the Vibrio vulnificus risk to raw oysters consumers. J FOOD ENG 2015. [DOI: 10.1016/j.jfoodeng.2014.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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Baumeister L, Hochman ME, Schwarz JR, Brinkmeyer R. Occurrence of Vibrio vulnificus and toxigenic Vibrio parahaemolyticus on sea catfishes from Galveston Bay, Texas. J Food Prot 2014; 77:1784-6. [PMID: 25285498 DOI: 10.4315/0362-028x.jfp-14-175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dorsal and pectoral fin spines from two species of sea catfishes (Bagre marinus and Ariopsis felis) landed at 54 sites in Galveston Bay, Texas, and its sub-bays from June to October 2005 were screened with traditional cultivation-based assays and quantitative PCR assays for Vibrio vulnificus and Vibrio parahaemolyticus. V. vulnificus was present on 51.2% of fish (n = 247), with an average of 403 ± 337 SD cells g(-1). V. parahaemolyticus was present on 94.2% (n = 247); 12.8% tested positive for the virulence-conferring tdh gene, having an average 2,039 ± 2,171 SD cells g(-1). The increasing trend in seafood consumption of "trash fishes" from lower trophic levels, such as sea catfishes, warrants evaluation of their life histories for association with pathogens of concern for human consumption.
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Affiliation(s)
- Leslie Baumeister
- Department of Marine Sciences, Texas A&M University, Galveston Campus, 200 Seawolf Parkway, Galveston, Texas 77553, USA
| | - Mona E Hochman
- Department of Marine Biology, Texas A&M University, Galveston Campus, 200 Seawolf Parkway, Galveston, Texas 77553, USA
| | - John R Schwarz
- Department of Marine Biology, Texas A&M University, Galveston Campus, 200 Seawolf Parkway, Galveston, Texas 77553, USA
| | - Robin Brinkmeyer
- Department of Marine Sciences, Texas A&M University, Galveston Campus, 200 Seawolf Parkway, Galveston, Texas 77553, USA.
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SLAYTON RB, NEWTON AE, DEPAOLA A, JONES JL, MAHON BE. Clam-associated vibriosis, USA, 1988-2010. Epidemiol Infect 2014; 142:1083-8. [PMID: 23920418 PMCID: PMC4615999 DOI: 10.1017/s0950268813001830] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/19/2013] [Accepted: 07/09/2013] [Indexed: 11/06/2022] Open
Abstract
Infections with Vibrio spp. have frequently been associated with consumption of bivalve molluscs, especially oysters, but illness associated with clams has also been well documented. We describe the 2312 domestically acquired foodborne Vibrio infections reported to the Cholera and Other Vibrio Illness Surveillance system from 1988 to 2010. Clams were associated with at least 4% (93 persons, 'only clams') and possibly as many as 24% (556 persons, 'any clams') of foodborne cases. Of those who consumed 'only clams', 77% of infections were caused by V. parahaemolyticus. Clam-associated illnesses were generally similar to those associated with other seafood consumption. Clams associated with these illnesses were most frequently harvested from the Atlantic coastal states and eaten raw. Our study describes the contribution of clams to the overall burden of foodborne vibriosis and indicates that a comprehensive programme to prevent foodborne vibriosis need to address the risks associated with clams.
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Affiliation(s)
- R. B. SLAYTON
- Epidemic Intelligence Service Officer, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - A. E. NEWTON
- Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - A. DEPAOLA
- U.S. Food and Drug Administration, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, AL, USA
| | - J. L. JONES
- U.S. Food and Drug Administration, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, AL, USA
| | - B. E. MAHON
- Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Application of a novel pathogenicity marker in a multiplex real-time PCR method to assess total and pathogenic Vibrio vulnificus in food and environmental samples. Food Control 2014. [DOI: 10.1016/j.foodcont.2013.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Tiruvayipati S, Bhassu S, Kumar N, Baddam R, Shaik S, Gurindapalli AK, Thong KL, Ahmed N. Genome anatomy of the gastrointestinal pathogen, Vibrio parahaemolyticus of crustacean origin. Gut Pathog 2013; 5:37. [PMID: 24330647 PMCID: PMC4029742 DOI: 10.1186/1757-4749-5-37] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/29/2013] [Indexed: 11/24/2022] Open
Abstract
Vibrio parahaemolyticus, an important human pathogen, is associated with gastroenteritis and transmitted through partially cooked seafood. It has become a major concern in the production and trade of marine food products. The prevalence of potentially virulent and pathogenic V. parahaemolyticus in raw seafood is of public health significance. Here we describe the genome sequence of a V. parahaemolyticus isolate of crustacean origin which was cultured from prawns in 2008 in Selangor, Malaysia (isolate PCV08-7). The next generation sequencing and analysis revealed that the genome of isolate PCV08-7 has closest similarity to that of V. parahaemolyticus RIMD2210633. However, there are certain unique features of the PCV08-7 genome such as the absence of TDH-related hemolysin (TRH), and the presence of HU-alpha insertion. The genome of isolate PCV08-7 encodes a thermostable direct hemolysin (TDH), an important virulence factor that classifies PCV08-7 isolate to be a serovariant of O3:K6 strain. Apart from these, we observed that there is certain pattern of genetic rearrangements that makes V. parahaemolyticus PCV08-7 a non-pandemic clone. We present detailed genome statistics and important genetic features of this bacterium and discuss how its survival, adaptation and virulence in marine and terrestrial hosts can be understood through the genomic blueprint and that the availability of genome sequence entailing this important Malaysian isolate would likely enhance our understanding of the epidemiology, evolution and transmission of foodborne Vibrios in Malaysia and elsewhere.
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Affiliation(s)
- Suma Tiruvayipati
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Subha Bhassu
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- Center of Biotechnology for Agriculture (CEBAR), University of Malaya, Kuala Lumpur, Malaysia
| | - Narender Kumar
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Ramani Baddam
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Sabiha Shaik
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Anil Kumar Gurindapalli
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Kwai Lin Thong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- Laboratory of Biomedical Science and Molecular Microbiology, UMBIO Research Cluster, University of Malaya, Kuala Lumpur, Malaysia
| | - Niyaz Ahmed
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
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Wood RR, Arias CR. Dynamics of Bacterial Communities in Postharvested Eastern Oyster (Crassostrea virginica) Maintained Under Refrigeration. JOURNAL OF AQUATIC FOOD PRODUCT TECHNOLOGY 2013. [DOI: 10.1080/10498850.2013.772270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Genotypic diversity and virulence characteristics of clinical and environmental Vibrio vulnificus isolates from the Baltic Sea region. Appl Environ Microbiol 2013; 79:3570-81. [PMID: 23542621 DOI: 10.1128/aem.00477-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The genetic diversity of Vibrio vulnificus isolates from clinical and environmental sources originating from the Baltic Sea region was evaluated by multilocus sequence typing (MLST), and possible relationships between MLST clusters, potential genotypic and phenotypic traits associated with pathogenicity, and source of isolation were investigated. The studied traits included genotyping of polymorphic loci (16S rRNA, vcg, and pilF), presence/absence of potential virulence genes, including nanA, nab, and genes of pathogenicity regions, metabolic features, hemolytic activity, resistance to human serum, and cytotoxicity to human intestinal cells. MLST generated 35 (27 new) sequence types and divided the 53 isolates (including four reference strains) into two main clusters, with cluster I containing biotype 1 and 2 isolates of mainly environmental origin and cluster II containing biotype 1 isolates of mainly clinical origin. Cluster II isolates were further subdivided into two branches. Branch IIB included isolates from recent cases of wound infections that were acquired at the German Baltic Sea coastline between 2010 and 2011 and isolates from seawater samples of the same regions isolated between 1994 and 2010. Comparing the MLST data with the results of genotyping and phenotyping showed that strains of MLST cluster II possess a number of additional pathogenicity-associated traits compared to cluster I strains. Rapid microbiological methods such as matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry combined with typing of selected virulence-associated traits (e.g., serum resistance, mannitol fermentation, nanA, and pathogenicity region XII) could be used for risk assessment purposes regarding V. vulnificus strains isolated from the Baltic Sea region.
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15
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Yokochi N, Tanaka S, Matsumoto K, Oishi H, Tashiro Y, Yoshikane Y, Nakashima M, Kanda K, Kobayashi G. Distribution of virulence markers among Vibrio vulnificus isolates of clinical and environmental origin and regional characteristics in Japan. PLoS One 2013; 8:e55219. [PMID: 23383115 PMCID: PMC3559389 DOI: 10.1371/journal.pone.0055219] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 12/20/2012] [Indexed: 12/20/2022] Open
Abstract
Background Vibrio vulnificus is an opportunistic human pathogen that is widely distributed in estuarine environments and is capable of causing necrotizing fasciitis and sepsis. In Japan, based on epidemiological research, the incidences of V. vulnificus were concentrated in Kyusyu, mainly in coastal areas of the Ariake Sea. To examine the virulence potential, various genotyping methods have recently been developed. This study aimed to investigate the distribution of virulence markers among V. vulnificus isolates of clinical and environmental origin in three coastal areas with different infection incidences and to determine whether these isolates have the siderophore encoding gene viuB. Methodology/Principal Findings We examined the distribution of genotypes of the 16S ribosomal ribonucleic acid (rRNA) gene, vvhA, vcg, and capsular polysaccharide (CPS), and the presence of viuB in 156 isolates collected from patients and environmental samples in Japan. The environmental samples were collected from three coastal areas: the Ariake Sea, Ise & Mikawa Bay, and Karatsu Bay. The results showed disparity in the ratios of genotypes depending on the sample origins. V. vulnificus isolates obtained from patients were classified into the clinical type for all genotypes. In the environmental isolates, the ratios of the clinical type for genotypes of the 16S rRNA gene, vvhA, and vcg were in the order of the Ariake Sea>Ise & Mikawa Bay>Karatsu Bay. Meanwhile, CPS analysis showed no significant difference. Most isolates possessed viuB. Conclusions Many V. vulnificus belonging to the clinical type existed in the Ariake Sea. Three coastal areas with different infection incidences showed distinct ratios of genotypes. This may indicate that the distribution of clinical isolates correlates with the incidence of V. vulnificus infection.
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Affiliation(s)
- Nana Yokochi
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan
| | - Shigemitsu Tanaka
- Biomaterials and Commodity Chemicals Research Division, Osaka Municipal Technical Research Institute, Osaka, Japan
| | - Kouichi Matsumoto
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Saga University, Saga, Japan
| | - Hirotaka Oishi
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Saga University, Saga, Japan
| | - Yukihiro Tashiro
- Institute of Advanced Study, Kyusyu University, Higashi-ku, Fukuoka, Japan
| | - Yu Yoshikane
- Tosa Food Business Creator Project Team, Kochi University, Nankoku, Kochi, Japan
| | - Mikio Nakashima
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Saga University, Saga, Japan
| | - Kohzo Kanda
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan
| | - Genta Kobayashi
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan
- * E-mail:
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DaSilva L, Parveen S, DePaola A, Bowers J, Brohawn K, Tamplin ML. Development and validation of a predictive model for the growth of Vibrio vulnificus in postharvest shellstock oysters. Appl Environ Microbiol 2012; 78:1675-81. [PMID: 22247136 PMCID: PMC3298140 DOI: 10.1128/aem.07304-11] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/30/2011] [Indexed: 11/20/2022] Open
Abstract
Postharvest growth of Vibrio vulnificus in oysters can increase risk of human infection. Unfortunately, limited information is available regarding V. vulnificus growth and survival patterns over a wide range of storage temperatures in oysters harvested from different estuaries and in different oyster species. In this study, we developed a predictive model for V. vulnificus growth in Eastern oysters (Crassostrea virginica) harvested from Chesapeake Bay, MD, over a temperature range of 5 to 30°C and then validated the model against V. vulnificus growth rates (GRs) in Eastern and Asian oysters (Crassostrea ariakensis) harvested from Mobile Bay, AL, and Chesapeake Bay, VA, respectively. In the model development studies, V. vulnificus was slowly inactivated at 5 and 10°C with average GRs of -0.0045 and -0.0043 log most probable number (MPN)/h, respectively. Estimated average growth rates at 15, 20, 25, and 30°C were 0.022, 0.042, 0.087, and 0.093 log MPN/h, respectively. With respect to Eastern oysters, bias (B(f)) and accuracy (A(f)) factors for model-dependent and -independent data were 1.02 and 1.25 and 1.67 and 1.98, respectively. For Asian oysters, B(f) and A(f) were 0.29 and 3.40. Residual variations in growth rate about the fitted model were not explained by season, region, water temperature, or salinity at harvest. Growth rate estimates for Chesapeake Bay and Mobile Bay oysters stored at 25 and 30°C showed relatively high variability and were lower than Food and Agricultural Organization (FAO)/WHO V. vulnificus quantitative risk assessment model predictions. The model provides an improved tool for designing and implementing food safety plans that minimize the risk associated with V. vulnificus in oysters.
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Affiliation(s)
- Ligia DaSilva
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland, USA
| | - Salina Parveen
- Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland, USA
| | - Angelo DePaola
- FDA, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, Alabama, USA
| | - John Bowers
- FDA, Division of Public Health and Biostatistics, College Park, Maryland, USA
| | - Kathy Brohawn
- Maryland Department of the Environment, Baltimore, Maryland, USA
| | - Mark L. Tamplin
- Food Safety Centre, Tasmanian Institute of Agricultural Research, University of Tasmania, Hobart, Tasmania, Australia
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Sialic acid catabolism and transport gene clusters are lineage specific in Vibrio vulnificus. Appl Environ Microbiol 2012; 78:3407-15. [PMID: 22344665 DOI: 10.1128/aem.07395-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sialic or nonulosonic acids are nine-carbon alpha ketosugars that are present in all vertebrate mucous membranes. Among bacteria, the ability to catabolize sialic acid as a carbon source is present mainly in pathogenic and commensal species of animals. Previously, it was shown that several Vibrio species carry homologues of the genes required for sialic acid transport and catabolism, which are genetically linked. In Vibrio cholerae on chromosome I, these genes are carried on the Vibrio pathogenicity island-2 region, which is confined to pathogenic isolates. We found that among the three sequenced Vibrio vulnificus clinical strains, these genes are present on chromosome II and are not associated with a pathogenicity island. To determine whether the sialic acid transport (SAT) and catabolism (SAC) region is universally present within V. vulnificus, we examined 67 natural isolates whose phylogenetic relationships are known. We found that the region was present predominantly among lineage I of V. vulnificus, which is comprised mainly of clinical isolates. We demonstrate that the isolates that contain this region can catabolize sialic acid as a sole carbon source. Two putative transporters are genetically linked to the region in V. vulnificus, the tripartite ATP-independent periplasmic (TRAP) transporter SiaPQM and a component of an ATP-binding cassette (ABC) transporter. We constructed an in-frame deletion mutation in siaM, a component of the TRAP transporter, and demonstrate that this transporter is essential for sialic acid uptake in this species. Expression analysis of the SAT and SAC genes indicates that sialic acid is an inducer of expression. Overall, our study demonstrates that the ability to catabolize and transport sialic acid is predominately lineage specific in V. vulnificus and that the TRAP transporter is essential for sialic acid uptake.
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Ji H, Chen Y, Guo Y, Liu X, Wen J, Liu H. Occurrence and characteristics of Vibrio vulnificus in retail marine shrimp in China. Food Control 2011. [DOI: 10.1016/j.foodcont.2011.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Staley C, Jones MK, Wright AC, Harwood VJ. Genetic and quantitative assessment of Vibrio vulnificus populations in oyster (Crassostrea virginica) tissues. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:543-549. [PMID: 23761333 DOI: 10.1111/j.1758-2229.2011.00256.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Vibrio vulnificus is a leading cause of shellfish-associated food-borne illness. US regulations stipulate shellfish processing procedures to limit V. vulnificus densities; however, the effect of these procedures on V. vulnificus strain distribution and/or genetic diversity is unknown. Vibrio vulnificus concentrations and strain diversity were analysed in various oyster tissues stored overnight at 26°C that were subsequently divided into two treatment groups: one received post-harvest processing (PHP) via individual quick freeze and one was stored on ice. Vibrio vulnificus densities were 10-fold lower in all PHP-treated tissues compared with untreated tissues. Genetic diversity of V. vulnificus was assessed by BOX-PCR genotyping and was high in all oyster tissues, but was significantly lower in untreated compared with PHP-treated oysters. BOX-PCR discriminated strains into BOX-C (clinical-associated) and BOX-E (environmental-associated) types based on a 1.1 kb DNA band, which correlated well (83% agreement) with 16S rRNA (A/B) typing. A significantly higher proportion of BOX-C isolates were recovered from PHP oysters compared with untreated oysters (24% of all isolates versus 12%) suggesting that BOX-C strains may be more resistant to treatment. These results reveal highly diverse populations of V. vulnificus in oysters with different responses to PHP, emphasizing the need to better understand the organism's ecology and population genetics to optimize food safety practices.
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Affiliation(s)
- Christopher Staley
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA Food Science & Human Nutrition Department, University of Florida, Gainesville, FL 32611, USA
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Vibrio vulnificus rtxA1 gene recombination generates toxin variants with altered potency during intestinal infection. Proc Natl Acad Sci U S A 2011; 108:1645-50. [PMID: 21220343 DOI: 10.1073/pnas.1014339108] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vibrio vulnificus is a food-borne bacterial pathogen associated with 1% of all food-related deaths, predominantly because of consumption of contaminated seafood. The ability of V. vulnificus to cause disease is linked to the production of a large cytotoxin called the "multifunctional-autoprocessing RTX" (MARTX(Vv)) toxin, a factor shown here to be an important virulence factor by the intragastric route of infection in mice. In this study, we examined genetic variation of the rtxA1 gene that encodes MARTX(Vv) in 40 V. vulnificus Biotype 1 strains and found four distinct variants of rtxA1 that encode toxins with different arrangements of effector domains. We provide evidence that these variants arose by recombination either with rtxA genes carried on plasmids or with the rtxA gene of Vibrio anguillarum. Contrary to expected results, the most common rtxA1 gene variant in clinical-type V. vulnificus encodes a toxin with reduced potency and is distinct from the toxin produced by strains isolated from market oysters. These results indicate that an important virulence factor of V. vulnificus is undergoing significant genetic rearrangement and may be subject to selection for reduced virulence in the environment. This finding would imply further that in the future on-going genetic variation of the MARTX(Vv) toxins could result in the emergence of novel strains with altered virulence in humans.
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21
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Genotype is correlated with but does not predict virulence of Vibrio vulnificus biotype 1 in subcutaneously inoculated, iron dextran-treated mice. Infect Immun 2011; 79:1194-207. [PMID: 21199909 DOI: 10.1128/iai.01031-10] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Vibrio vulnificus is the leading cause of reported deaths from infections related to consumption of seafood in the United States. Affected predisposed individuals frequently die rapidly from sepsis. Otherwise healthy people can experience severe wound infection, which can lead to sepsis and death. A question is why, with so many people consuming contaminated raw oysters, the incidence of severe V. vulnificus disease is low. Molecular typing systems have shown associations of V. vulnificus genotypes and the environmental or clinical source of the strains, suggesting that different genotypes possess different virulence potentials. We examined 69 V. vulnificus biotype 1 strains that were genotyped by several methods and evaluated them for virulence in a subcutaneously inoculated iron dextran-treated mouse model. By examining the relationships between skin infection, systemic liver infection, and presumptive death (a decrease in body temperature), we determined that liver infection is predicated on severe skin infection and that death requires significant liver infection. Although most strains caused severe skin infection, not every strain caused systemic infection and death. Strains with polymorphisms at multiple loci (rrn, vcg, housekeeping genes, and repetitive DNA) designated profile 2 were more likely to cause lethal systemic infection with more severe indicators of virulence than were profile 1 strains with different polymorphisms at these loci. However, some profile 1 strains were lethal and some profile 2 strains did not cause systemic infection. Therefore, current genotyping schemes cannot strictly predict the virulence of V. vulnificus strains and further investigation is needed to identify virulence genes as markers of virulence.
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Gauthier JD, Jones MK, Thiaville P, Joseph JL, Swain RA, Krediet CJ, Gulig PA, Teplitski M, Wright AC. Role of GacA in virulence of Vibrio vulnificus. Microbiology (Reading) 2010; 156:3722-3733. [PMID: 20817642 DOI: 10.1099/mic.0.043422-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The GacS/GacA two-component signal transduction system regulates virulence, biofilm formation and symbiosis in Vibrio species. The present study investigated this regulatory pathway in Vibrio vulnificus, a human pathogen that causes life-threatening disease associated with the consumption of raw oysters and wound infections. Small non-coding RNAs (csrB1, csrB2, csrB3 and csrC) commonly regulated by the GacS/GacA pathway were decreased (P<0.0003) in a V. vulnificus CMCP6 ΔgacA : : aph mutant compared with the wild-type parent, and expression was restored by complementation of the gacA deletion mutation in trans. Of the 20 genes examined by RT-PCR, significant reductions in the transcript levels of the mutant in comparison with the wild-type strain were observed only for genes related to motility (flaA), stationary phase (rpoS) and protease (vvpE) (P=0.04, 0.01 and 0.002, respectively). Swimming motility, flagellation and opaque colony morphology indicative of capsular polysaccharide (CPS) were unchanged in the mutant, while cytotoxicity, protease activity, CPS phase variation and the ability to acquire iron were decreased compared with the wild-type (P<0.01). The role of gacA in virulence of V. vulnificus was also demonstrated by significant impairment in the ability of the mutant strain to cause either skin (P<0.0005) or systemic infections (P<0.02) in subcutaneously inoculated, non-iron-treated mice. However, the virulence of the mutant was equivalent to that of the wild-type in iron-treated mice, demonstrating that the GacA pathway in V. vulnificus regulates the virulence of this organism in an iron-dependent manner.
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Affiliation(s)
- Julie D. Gauthier
- Department of Biological Sciences, Loyola University, New Orleans, LA 70118, USA
- Food Science and Human Nutrition Department, 212 Aquatic Food Products Laboratory, University of Florida, Gainesville, FL 32611, USA
| | - Melissa K. Jones
- Food Science and Human Nutrition Department, 212 Aquatic Food Products Laboratory, University of Florida, Gainesville, FL 32611, USA
| | - Patrick Thiaville
- Molecular Genetics and Microbiology Department, R1-144 Academic Research Building, University of Florida, Gainesville, FL 32611, USA
| | - Jennifer L. Joseph
- Molecular Genetics and Microbiology Department, R1-144 Academic Research Building, University of Florida, Gainesville, FL 32611, USA
| | - Rick A. Swain
- Food Science and Human Nutrition Department, 212 Aquatic Food Products Laboratory, University of Florida, Gainesville, FL 32611, USA
| | - Cory J. Krediet
- Soil and Water Science Department, 330E Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Paul A. Gulig
- Molecular Genetics and Microbiology Department, R1-144 Academic Research Building, University of Florida, Gainesville, FL 32611, USA
| | - Max Teplitski
- Soil and Water Science Department, 330E Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Anita C. Wright
- Food Science and Human Nutrition Department, 212 Aquatic Food Products Laboratory, University of Florida, Gainesville, FL 32611, USA
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Gulig PA, Crécy-Lagard VD, Wright AC, Walts B, Telonis-Scott M, McIntyre LM. SOLiD sequencing of four Vibrio vulnificus genomes enables comparative genomic analysis and identification of candidate clade-specific virulence genes. BMC Genomics 2010; 11:512. [PMID: 20863407 PMCID: PMC3091676 DOI: 10.1186/1471-2164-11-512] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 09/24/2010] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Vibrio vulnificus is the leading cause of reported death from consumption of seafood in the United States. Despite several decades of research on molecular pathogenesis, much remains to be learned about the mechanisms of virulence of this opportunistic bacterial pathogen. The two complete and annotated genomic DNA sequences of V. vulnificus belong to strains of clade 2, which is the predominant clade among clinical strains. Clade 2 strains generally possess higher virulence potential in animal models of disease compared with clade 1, which predominates among environmental strains. SOLiD sequencing of four V. vulnificus strains representing different clades (1 and 2) and biotypes (1 and 2) was used for comparative genomic analysis. RESULTS Greater than 4,100,000 bases were sequenced of each strain, yielding approximately 100-fold coverage for each of the four genomes. Although the read lengths of SOLiD genomic sequencing were only 35 nt, we were able to make significant conclusions about the unique and shared sequences among the genomes, including identification of single nucleotide polymorphisms. Comparative analysis of the newly sequenced genomes to the existing reference genomes enabled the identification of 3,459 core V. vulnificus genes shared among all six strains and 80 clade 2-specific genes. We identified 523,161 SNPs among the six genomes. CONCLUSIONS We were able to glean much information about the genomic content of each strain using next generation sequencing. Flp pili, GGDEF proteins, and genomic island XII were identified as possible virulence factors because of their presence in virulent sequenced strains. Genomic comparisons also point toward the involvement of sialic acid catabolism in pathogenesis.
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Affiliation(s)
- Paul A Gulig
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Anita C Wright
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida, USA
| | - Brandon Walts
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
| | - Marina Telonis-Scott
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
- Department of Genetics, University of Melbourne, 3010 Australia
| | - Lauren M McIntyre
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
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Genetic characterization of Vibrio vulnificus strains from tilapia aquaculture in Bangladesh. Appl Environ Microbiol 2010; 76:4890-5. [PMID: 20495047 DOI: 10.1128/aem.00636-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Outbreaks of Vibrio vulnificus wound infections in Israel were previously attributed to tilapia aquaculture. In this study, V. vulnificus was frequently isolated from coastal but not freshwater aquaculture in Bangladesh. Phylogenetic analyses showed that strains from Bangladesh differed remarkably from isolates commonly recovered elsewhere from fish or oysters and were more closely related to strains of clinical origin.
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25
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Han F, Pu S, Hou A, Ge B. Characterization of Clinical and Environmental Types ofVibrio vulnificusIsolates from Louisiana Oysters. Foodborne Pathog Dis 2009; 6:1251-8. [DOI: 10.1089/fpd.2009.0343] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Feifei Han
- Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana
| | - Shuaihua Pu
- Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana
| | - Aixin Hou
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana
| | - Beilei Ge
- Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana
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26
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Dechet AM, Yu PA, Koram N, Painter J. Nonfoodborne Vibrio infections: an important cause of morbidity and mortality in the United States, 1997-2006. Clin Infect Dis 2008; 46:970-6. [PMID: 18444811 DOI: 10.1086/529148] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Infections due to Vibrio species cause an estimated 8000 illnesses annually, often through consumption of undercooked seafood. Like foodborne Vibrio infections, nonfoodborne Vibrio infections (NFVI) also result in serious illness, but awareness of these infections is limited. METHODS We analyzed illnesses occuring during the period 1997-2006 that were reported to the Centers for Disease Control and Prevention's Cholera and Other Vibrio Illness Surveillance system. The diagnosis of NFVI required isolation of Vibrio species from a patient with contact with seawater. RESULTS Of 4754 Vibrio infections reported, 1210 (25%) were NFVIs. Vibrio vulnificus infections were the most common (accounting for 35% of NFVIs), with 72% of V. vulnificus infections reported from residents of Gulf Coast states. Infections due to V. vulnificus resulted in fever (72% of cases), cellulitis (85%), amputation (10%), and death (17%). V. vulnificus caused 62 NFVI-associated deaths (78%). Recreational activities accounted for 70% of exposures for patients with NFVIs associated with all species. Patients with liver disease were significantly more likely to die as a result of infection (odds ratio, 7.8; 95% confidence interval, 2.8-21.9). Regardless of pre-existing conditions, patients were more likely to die when hospitalization occurred >2 days after symptom onset (odds ratio, 2.9; 95% confidence interval, 1.8-4.8). CONCLUSION NFVIs, especially those due to V. vulnificus, demonstrate high morbidity and mortality. Persons with liver disease should be advised of the risks associated with seawater exposure if a wound is already present or is likely to occur. Clinicians should consider Vibrio species as an etiologic agent in infections occurring in persons with recent seawater exposure, even if the individual was only exposed during recreational marine activities. Immediate antibiotic treatment with aggressive monitoring is advised in suspected cases.
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Affiliation(s)
- Amy M Dechet
- AIDS Education and Training Center, San Francisco General Hospital, San Francisco, California, USA
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Lee JL, Levin R. Discrimination of γ-irradiated and nonirradiated Vibrio vulnificus by using real-time polymerase chain reaction. J Appl Microbiol 2008; 104:728-34. [DOI: 10.1111/j.1365-2672.2007.03589.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Shekar M, Acharya S, Karunasagar I, Karunasagar I. Variable repeat regions in the genome of Vibrio vulnificus and polymorphism in one of the loci in strains isolated from oysters. Int J Food Microbiol 2008; 123:240-5. [PMID: 18374439 DOI: 10.1016/j.ijfoodmicro.2008.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Revised: 02/12/2008] [Accepted: 02/12/2008] [Indexed: 10/22/2022]
Abstract
Vibrio vulnificus an estuarine bacterium is associated with severe wound infections and fatal septicemia related to consumption of raw shellfish. In this study we screened the two whole genome sequences available for V. vulnificus in GenBank for the presence of variable number of tandem repeat (VNTR) regions. Five potential VNTR loci with unit repeat size ranging from 6-7 nucleotides were identified for V. vulnificus genome. One of the loci designated Vv1 was selected to detect the repeat number present in V. vulnificus strains isolated from oyster samples in India. Twenty six of the thirty samples tested were found to be highly polymorphic for the Vv1 locus. Copy numbers for the hexanucleotide motif ranged from 4-55, giving rise to a total of 17 polymorphic groups. Our analysis, shows that different genotypic variants exist in the environment and the VNTR loci studied can be used as a marker for strain discrimination and in epidemiological study of this organism.
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Affiliation(s)
- Malathi Shekar
- Department of Fishery Microbiology, Karnataka Veterinary, Animal and Fisheries Sciences University, College of Fisheries , Mangalore 575 002, India
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Bisharat N, Cohen DI, Maiden MC, Crook DW, Peto T, Harding RM. The evolution of genetic structure in the marine pathogen, Vibrio vulnificus. INFECTION GENETICS AND EVOLUTION 2007; 7:685-93. [PMID: 17716955 DOI: 10.1016/j.meegid.2007.07.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 05/22/2007] [Accepted: 07/13/2007] [Indexed: 11/22/2022]
Abstract
Multi-locus sequence types (MLST) from a global collection of Vibrio vulnificus isolates were analysed for the contribution of recombination to the evolution of two divergent clusters of strains and a human-pathogenic hybrid genotype, which caused a disease outbreak in Israel. Recombination contributes more substantially than mutation to generating strain diversity. For allelic diversity within loci, the ratio of recombination to mutation events is approximately 2:1. The role of recombination relative to mutation in the generation of new MLST variants of V. vulnificus within the clusters is comparable to that of other highly recombining bacteria such as Neisseria meningitidis. However, across the divide between the two major clusters of V. vulnificus strains, there is substantial linkage disequilibrium, lower estimates for recombination rates and shorter estimates of recombination tract length. We account for these differences between V. vulnificus and N. meningitidis by attributing them to the presence of the unusual genetic structure within V. vulnificus. The reason for the presence of distinct and divergent genomes remains unresolved. Two possible explanations put forward for future study are first, ecologically based population structure within V. vulnificus and second, a recombination donor from a phenotypically differentiated species.
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Affiliation(s)
- Naiel Bisharat
- Department of Epidemiology and Preventive Medicine, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
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Sequence characterization and comparative analysis of three plasmids isolated from environmental Vibrio spp. Appl Environ Microbiol 2007; 73:7703-10. [PMID: 17921277 DOI: 10.1128/aem.01577-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The horizontal transfer of genes by mobile genetic elements such as plasmids and phages can accelerate genome diversification of Vibrio spp., affecting their physiology, pathogenicity, and ecological character. In this study, sequence analysis of three plasmids from Vibrio spp. previously isolated from salt marsh sediment revealed the remarkable diversity of these elements. Plasmids p0908 (81.4 kb), p23023 (52.5 kb), and p09022 (31.0 kb) had a predicted 99, 64, and 32 protein-coding sequences and G+C contents of 49.2%, 44.7%, and 42.4%, respectively. A phylogenetic tree based on concatenation of the host 16S rRNA and rpoA nucleotide sequences indicated p23023 and p09022 were isolated from strains most closely related to V. mediterranei and V. campbellii, respectively, while the host of p0908 forms a clade with V. fluvialis and V. furnissii. Many predicted proteins had amino acid identities to proteins of previously characterized phages and plasmids (24 to 94%). Predicted proteins with similarity to chromosomally encoded proteins included RecA, a nucleoid-associated protein (NdpA), a type IV helicase (UvrD), and multiple hypothetical proteins. Plasmid p0908 had striking similarity to enterobacteria phage P1, sharing genetic organization and amino acid identity for 23 predicted proteins. This study provides evidence of genetic exchange between Vibrio plasmids, phages, and chromosomes among diverse Vibrio spp.
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Drake SL, DePaola A, Jaykus LA. An Overview of Vibrio vulnificus and Vibrio parahaemolyticus. Compr Rev Food Sci Food Saf 2007. [DOI: 10.1111/j.1541-4337.2007.00022.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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32
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González-Escalona N, Whitney B, Jaykus LA, DePaola A. Comparison of direct genome restriction enzyme analysis and pulsed-field gel electrophoresis for typing of Vibrio vulnificus and their correspondence with multilocus sequence typing data. Appl Environ Microbiol 2007; 73:7494-500. [PMID: 17720834 PMCID: PMC2168220 DOI: 10.1128/aem.00738-07] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We compared the potential of direct genome restriction enzyme analysis (DGREA) and pulsed-field gel electrophoresis (PFGE) for discriminating Vibrio vulnificus isolates from clinical (23) and environmental (17) sources. The genotypes generated by both methodologies were compared to previous multilocus sequence typing (MLST) data. DGREA established clearer relationships among V. vulnificus strains and was more consistent with MLST than with PFGE. DGREA is a very promising tool for epidemiological and ecological studies of V. vulnificus.
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Plotkin BJ, Konaklieva MI. Surface properties of Vibrio vulnificus. Lett Appl Microbiol 2007; 44:426-30. [PMID: 17397482 DOI: 10.1111/j.1472-765x.2006.02083.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Vibrio vulnificus adheres to a diverse range of surfaces, ranging from the chitinous exoskeleton of mollusks to human tissue. To determine whether environmental and human clinical isolates exhibit different adhesion traits, we studied the ability of 10 environmental isolates and 10 clinical isolates to adhere to human epithelial cells and hydrocarbons with log P values ranging from 3.1 to 8.2. METHODS AND RESULTS All isolates adhered to varying levels to epithelial cells, and were inhibited to various extents from adherence by mannose and fructose. There was a lack of correlation between adherence to either hydrocarbons or cells and colony opacity. Adherence to hydrocarbons was optimal for solvents with a log P < 8.2. CONCLUSIONS Vibrio vulnificus clinical and environmental isolates exhibit differential adherence to epithelial cells and hydrocarbons. SIGNIFICANCE AND IMPACT OF THE STUDY The differential adherence of organisms to hydrocarbons based on log P may have utility in drug design and enhancement of food safety.
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Affiliation(s)
- B J Plotkin
- Department of Microbiology and Immunology, Midwestern University, Downers Grove, IL 60515, USA.
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Vickery MCL, Nilsson WB, Strom MS, Nordstrom JL, DePaola A. A real-time PCR assay for the rapid determination of 16S rRNA genotype in Vibrio vulnificus. J Microbiol Methods 2007; 68:376-84. [PMID: 17070612 DOI: 10.1016/j.mimet.2006.02.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 02/09/2006] [Indexed: 10/24/2022]
Abstract
In a terminal restriction fragment polymorphism (T-RFLP) study, we recently reported a significant association between the type B 16S rRNA gene and clinical strains of Vibrio vulnificus associated with the consumption of raw oysters. In the present study we describe a real-time PCR assay for the rapid determination of the 16S rRNA type of V. vulnificus isolates. This assay was used to reexamine the 16S rRNA gene type in the strains studied previously by T-RFLP and additional isolates from selected sources. Analyses revealed that 15 of the strains (10 environmental and 5 clinical) previously found to be 16S rRNA type A actually appear to possess both the type A and B genes. The presence of both alleles was confirmed by cloning and sequencing both gene types from one strain. To our knowledge, this is the first report of 16S rRNA sequence heterogeneity within individual strains of V. vulnificus. The findings confirm the T-RFLP data that 16S rRNA type may be a useful marker for determining the clinical significance of V. vulnificus in disease in humans and cultured eels. The real-time PCR assay is much more rapid and less resource-intensive than T-RFLP, and should facilitate further study of the occurrence and distribution of the 16S rRNA genotypes of V. vulnificus. These studies should provide more definitive estimates of the risks associated with this organism and may lead to a better understanding of its virulence mechanism(s).
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Affiliation(s)
- Michael C L Vickery
- Gulf Coast Seafood Laboratory, U. S. Food and Drug Administration, Dauphin Island, Alabama 36528, United States.
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Chatzidaki-Livanis M, Hubbard MA, Gordon K, Harwood VJ, Wright AC. Genetic distinctions among clinical and environmental strains of Vibrio vulnificus. Appl Environ Microbiol 2006; 72:6136-41. [PMID: 16957239 PMCID: PMC1563656 DOI: 10.1128/aem.00341-06] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio vulnificus causes rare but frequently fatal septicemia associated with raw oyster consumption by persons with underlying hepatic or immune system dysfunction. The virulence potential of environmental reservoirs appears widely distributed, because most strains are virulent in animal models; however, several investigations recently demonstrated genetic divergence among strains from clinical versus environmental origin at independent genetic loci. The present study used PCR to screen DNA polymorphisms in strains from environmental (n = 35) or clinical (n = 33) sources, and genomic relationships were determined by repetitive extragenic palindromic DNA PCR (rep-PCR) typing. Significant (P < 0.01) association was observed for typical "clinical" or "environmental" polymorphism profiles based on strain origin. Most oyster isolates (88%), including all of those with the "environmental" profile, also formed a single rep-PCR genogroup. Clinical isolates within this group did not have the typical "clinical" profile. On the other hand, clinical isolates with the typical polymorphism profile were distributed among multiple rep-PCR genogroups, demonstrating greater genetic diversity than was evident by profiling genetic polymorphisms. Wound isolates were genetically distinct from typical blood isolates by all assays. Strains from an outbreak of wound infections in Israel (biotype 3) were closely related to several U.S. strains by rep-PCR, indicating potential reservoirs of emerging disease. Strains genetically related to blood isolates appeared to be relatively rare in oysters, as only one had the "clinical" polymorphism profile or clustered by rep-PCR. However, this study was not an extensive survey, and more sampling using rep-PCR for sensitive genetic discrimination is needed to determine the virulence potential of environmental reservoirs.
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Affiliation(s)
- Maria Chatzidaki-Livanis
- University of Florida, Department of Food Science and Human Nutrition, P.O. Box 110370, Gainesville, FL 32611, USA
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Starks AM, Bourdage KL, Thiaville PC, Gulig PA. Use of a marker plasmid to examine differential rates of growth and death between clinical and environmental strains of Vibrio vulnificus in experimentally infected mice. Mol Microbiol 2006; 61:310-23. [PMID: 16856938 DOI: 10.1111/j.1365-2958.2006.05227.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Vibrio vulnificus is Gram-negative bacterium that contaminates oysters, causing highly lethal sepsis after consumption of raw oysters and wound infection. We previously described two sets of V. vulnificus strains with different levels of virulence in subcutaneously inoculated iron dextran-treated mice. Both virulent, clinical strains and attenuated, environmental strains could be recovered in high numbers from skin lesions and livers; however, the attenuated environmental strains required significantly higher numbers of colony-forming units (cfu) in the inoculum to produce lethal infection. Using some of these strains and an additional clinical strain, we presently asked if the different abilities to cause infection between the clinical and environmental strains were due to differences in rates of growth or death of the bacteria in the mouse host. We therefore constructed a marker plasmid, pGTR902, that functions as a replicon only in the presence of arabinose, which is not present in significant levels in animal tissues. V. vulnificus strains containing pGTR902 were inoculated into iron dextran-treated and untreated mice. Measuring the proportion of bacteria that had maintained the marker plasmid recovered from mice enabled us to monitor the number of in vivo divisions, hence growth rate; whereas measuring the number of marker plasmid-containing bacteria recovered enabled the measurement of death of the vibrios in the mice. The numbers of bacterial divisions in vivo for all of the strains over a 12-15 h infection period were not significantly different in iron dextran-treated mice; however, the rate of death of one environmental strain was significantly higher compared with the clinical strains. Infection of non-iron dextran-treated mice with clinical strains demonstrated that the greatest effect of iron dextran-treatment was increased growth rate, while one clinical strain also experienced increased death in untreated mice. V. vulnificus inoculated into iron dextran-treated mice replicated extremely rapidly over the first 4 h of infection with doubling times of approximately 15-28 min. In contrast, one of the environmental strains exhibited a reduced early growth rate. These results demonstrate that differences in virulence among naturally occurring V. vulnificus can be explained by diverse abilities to replicate rapidly in or resist defences of the host. The marker plasmid pGTR902 should be useful for examining virulence of bacteria in terms of differentiating growth verses death in animal hosts for most Gram-negative bacteria.
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Affiliation(s)
- Angela M Starks
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
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Chatzidaki-Livanis M, Jones MK, Wright AC. Genetic variation in the Vibrio vulnificus group 1 capsular polysaccharide operon. J Bacteriol 2006; 188:1987-98. [PMID: 16484211 PMCID: PMC1426558 DOI: 10.1128/jb.188.5.1987-1998.2006] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio vulnificus produces human disease associated with raw-oyster consumption or wound infections, but fatalities are limited to persons with chronic underlying illness. Capsular polysaccharide (CPS) is required for virulence, and CPS expression correlates with opaque (Op) colonies that show "phase variation" to avirulent translucent (Tr) phenotypes with reduced CPS. The results discussed here confirmed homology of a V. vulnificus CPS locus to the group 1 CPS operon in Escherichia coli. However, two distinct V. vulnificus genotypes or alleles were associated with the operon, and they diverged at sequences encoding hypothetical proteins and also at unique, intergenic repetitive DNA elements. Phase variation was examined under conditions that promoted high-frequency transition of Op to Tr forms. Recovery of Tr isolates in these experiments showed multiple genotypes, which were designated TR1, TR2, and TR3: CPS operons of TR1 isolates were identical to the Op parent, and cells remained phase variable but expressed reduced CPS. TR2 and TR3 showed deletion mutations in one (wzb) or multiple genes, respectively, and deletion mutants were acapsular and locked in the Tr phase. Complementation in trans restored the Op phenotype in strains with the wzb deletion mutation. Allelic variation in repetitive elements determined the locations, rates, and extents of deletion mutations. Thus, different mechanisms are responsible for reversible phase variation in CPS expression versus genetic deletions in the CPS operon of V. vulnificus. Repetitive-element-mediated deletion mutations were highly conserved within the species and are likely to promote survival in estuarine environments.
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Affiliation(s)
- Maria Chatzidaki-Livanis
- University of Florida, Department of Food Science and Human Nutrition, P.O. Box 110370, Gainesville, FL 32611, USA
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Wong HC, Liu SH, Chen MY. Virulence and stress susceptibility of clinical and environmental strains of Vibrio vulnificus isolated from samples from Taiwan and the United States. J Food Prot 2005; 68:2533-40. [PMID: 16355823 DOI: 10.4315/0362-028x-68.12.2533] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Vibrio vulnificus is an estuarine bacterium that causes severe wound infection and septicemia with high mortality. It also can be transmitted through the consumption of raw contaminated seafood and is an important foodborne pathogen. A total of 40 environmental and clinical V. vulnificus strains isolated from the United States and Taiwan were analyzed for virulence in animals, the presence of virulence-associated factors, and susceptibility to environmental stresses. Virulence in mice was exhibited by 85% of the environmental strains and 95% of the clinical strains. Strains from environmental or clinical sources were similar in virulence-associated phenotypes (protease activity, utilization of transferrin-bound iron, hemolysis, and inactivation in serum) and susceptibility to various stresses (4 and 52 degrees C, 0.1 and 10% NaCl, and pH 3.2), except freeze-thaw treatment. The clinical strains killed experimental animals after a shorter incubation time than did the environmental strains. Most of the 15 virulence-associated genes examined were present in most of the strains, regardless of their sources or virulence, with the exception of vvh, flgF, and purH. vvh was significantly more common in clinical strains than in environmental strains, and vvh, flgF, and purH were more common in virulent strains than in nonvirulent strains. These data may be helpful in devising strategies to manage or reduce the presence of V. vulnificus in foods.
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Affiliation(s)
- Hin-Chung Wong
- Department of Microbiology, Soochow University, Taipei, Taiwan 111, Republic of China.
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Rosche TM, Yano Y, Oliver JD. A rapid and simple PCR analysis indicates there are two subgroups of Vibrio vulnificus which correlate with clinical or environmental isolation. Microbiol Immunol 2005; 49:381-9. [PMID: 15840964 DOI: 10.1111/j.1348-0421.2005.tb03731.x] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vibrio vulnificus is an estuarine bacterium which is the causative agent of both food-borne disease and wound infection. Although V. vulnificus is commonly found in molluscan shellfish at high numbers, the incidence of disease is relatively low, leading to the hypothesis that not all strains of V. vulnificus are equally virulent. Unfortunately, there is currently no easy test to identify virulent strains of this species. We have previously identified a 200 bp randomly amplified polymorphic DNA (RAPD) PCR amplicon associated with clinical isolates. DNA sequence data from this locus in six clinical and four environmental isolates showed that the strains could be divided into two groups, which we termed C-type (correlates with clinical origin) and E-type (correlates with environmental origin). We designed PCR primers that could distinguish between the two groups, and typed 55 randomly selected strains. We found that 90% of the C-type strains were clinical isolates, while 93% of environmental isolates were classified as E-type. The region directly downstream of this locus contained a heptanucleotide sequence repeated various times depending on the strain. Using a PCR-based assay to detect the repeat number present in a given strain, we found a statistically significant correlation with the C/E type classification and the number of repeats. The data reported here are consistent with the existence of two genotypes of V. vulnificus, with the C-type being a strong indicator of potential virulence.
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Affiliation(s)
- Thomas M Rosche
- Department of Biology, University of North Carolina at Charlotte, NC 28223, USA
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Parvathi A, Kumar HS, Karunasagar I, Karunasagar I. Study of the occurrence of Vibrio vulnificus in oysters in India by polymerase chain reaction (PCR) and heterogeneity among V. vulnificus by randomly amplified polymorphic DNA PCR and gyrB sequence analysis. Environ Microbiol 2005; 7:995-1002. [PMID: 15946295 DOI: 10.1111/j.1462-2920.2005.00770.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The pathogenic bacterium Vibrio vulnificus is widely distributed in estuarine waters throughout the world. In this study, the presence of V. vulnificus in oysters was studied both by conventional culture and DNA-based molecular technique. Following enrichment in alkaline peptone water (APW), the bacteria were lysed and a nested polymerase chain reaction (PCR) for vvhA gene was performed. The effect of duration of enrichment on the sensitivity of detection by PCR was evaluated. The organism was isolated from 43% of samples after 18 h enrichment in APW by conventional culture method. Nested PCR amplifying a fragment of vvhA gene detected the organism in 11%, 60% and 81% of samples following 0, 6 and 18 h of enrichment. All the biochemically identified V. vulnificus strains possessed vvhA gene and belonged to biotype 1. The genetic relatedness among the strains was studied by randomly amplified polymorphic DNA (RAPD) PCR and gyrB sequence analysis. The results suggest the presence of two distinct clonal groups of V. vulnificus in oysters in India. The study demonstrates, for the first time that gyrB sequence analysis could be used to study the genetic diversity of V. vulnificus.
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Affiliation(s)
- Ammini Parvathi
- Department of Fishery Microbiology, University of Agricultural Sciences, College of Fisheries, Kankanady, Mangalore, India
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Levin RE. Vibrio vulnificus, a Notably Lethal Human Pathogen Derived from Seafood: A Review of Its Pathogenicity, Subspecies Characterization, and Molecular Methods of Detection. FOOD BIOTECHNOL 2005. [DOI: 10.1081/fbt-200049071] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Harwood VJ, Gandhi JP, Wright AC. Methods for isolation and confirmation of Vibrio vulnificus from oysters and environmental sources: a review. J Microbiol Methods 2004; 59:301-16. [PMID: 15488274 DOI: 10.1016/j.mimet.2004.08.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 06/29/2004] [Accepted: 08/06/2004] [Indexed: 12/17/2022]
Abstract
The gram-negative bacterium Vibrio vulnificus is a natural inhabitant of estuarine waters and poses a significant health threat to humans who suffer from immune disorders, liver disease, or hemochromatosis (iron overload). V. vulnificus enters human hosts via wound infections or consumption of raw shellfish (primarily oysters), and infections frequently progress to septicemia and death in susceptible individuals. Prevalence in waters and shellfish is not correlated with fecal indicator organisms; therefore, species-specific detection and enumeration of V. vulnificus in the environment has become a priority for agencies that are responsible for shellfish safety. The many selective-differential media developed for isolation of Vibrio spp., and specifically for V. vulnificus detection, are reviewed here; however, none of the media developed to date combines the sensitivity to low numbers with the specificity necessary to inhibit growth of other organisms. Therefore, immunological and molecular protocols are needed for confirmation of the identity of the organism and are discussed in detail. Methods under development that hold promise for rapid, accurate, and sensitive detection and enumeration of the organism include multiplex and real-time PCR. Developing technologies that have proven useful for detection and investigation of other pathogens such as biosensors, spectroscopy and microarrays may provide the next generation of tools for investigation of the prevalence and ecology of V. vulnificus.
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Affiliation(s)
- Valerie J Harwood
- Department of Biology, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA.
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Panicker G, Vickery MCL, Bej AK. Multiplex PCR detection of clinical and environmental strains ofVibrio vulnificusin shellfish. Can J Microbiol 2004; 50:911-22. [PMID: 15644908 DOI: 10.1139/w04-085] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, we developed a PCR-based rapid detection method for clinically important pathogenic strains of Vibrio vulnificus. Positive amplification of the 504-bp viuB fragment was seen in all 22 clinical isolates tested but only in 8 out of 33 environmental isolates. The combination of the species-specific 205-bp vvh fragment along with viuB in a multiplexed PCR enabled us to confirm the presence of potentially pathogenic strains of V. vulnificus. No amplification of other Vibrio spp. or non-Vibrio bacteria was evidenced, suggesting a high specificity of detection by this method. The sensitivity of detection for both targeted genes was 10 pg of purified DNA, which correlated with 103V. vulnificus CFU in 1 mL of pure culture or 1 g un-enriched seeded oyster tissue homogenate. This sensitivity was improved to 1 CFU per gram of oyster tissue homogenate in overnight-enriched samples. A SYBR Green I based real-time PCR method was also developed that was shown to produce results consistent with the conventional PCR method. Application of the multiplexed real-time PCR to natural oyster tissue homogenates exhibited positive detection of vvh in 51% of the samples collected primarily during the summer months; however, only 15% of vvh positive samples exhibited viuB amplicons. The rapid, sensitive, and specific detection of clinically important pathogenic V. vulnificus in shellfish would be beneficial in reducing illnesses and deaths caused by this pathogen.Key words: Vibrio, multiplex PCR, shellfish, SYBR Green I, real-time PCR.
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Affiliation(s)
- Gitika Panicker
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294-1170, USA
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