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Journal of Microbiology (Seoul, Korea) Feb 2005Vibrio vulnificus is an opportunistic pathogen of humans that has the capability of causing rare, yet devastating disease. The bacteria are naturally present in... (Review)
Review
Vibrio vulnificus is an opportunistic pathogen of humans that has the capability of causing rare, yet devastating disease. The bacteria are naturally present in estuarine environments and frequently contaminate seafoods. Within days of consuming uncooked, contaminated seafood, predisposed individuals can succumb to sepsis. Additionally, in otherwise healthy people, V. vulnificus causes wound infection that can require amputation or lead to sepsis. These diseases share the characteristics that the bacteria multiply extremely rapidly in host tissues and cause extensive damage. Despite the analysis of virulence for over 20 years using a combination of animal and cell culture models, surprisingly little is known about the mechanisms by which V. vulnificus causes disease. This is in part because of differences observed using animal models that involve infection with bacteria versus injection of toxins. However, the increasing use of genetic analysis coupled with detailed animal models is revealing new insight into the pathogenesis of V. vulnificus disease.
Topics: Animals; Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Mice; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 15765065
DOI: No ID Found -
Communications Biology Jun 2022Stressosomes are stress-sensing protein complexes widely conserved among bacteria. Although a role in the regulation of the general stress response is well documented in...
Stressosomes are stress-sensing protein complexes widely conserved among bacteria. Although a role in the regulation of the general stress response is well documented in Gram-positive bacteria, the activating signals are still unclear, and little is known about the physiological function of stressosomes in the Gram-negative bacteria. Here we investigated the stressosome of the Gram-negative marine pathogen Vibrio vulnificus. We demonstrate that it senses oxygen and identified its role in modulating iron-metabolism. We determined a cryo-electron microscopy structure of the VvRsbR:VvRsbS stressosome complex, the first solved from a Gram-negative bacterium. The structure points to a variation in the VvRsbR and VvRsbS stoichiometry and a symmetry breach in the oxygen sensing domain of VvRsbR, suggesting how signal-sensing elicits a stress response. The findings provide a link between ligand-dependent signaling and an output - regulation of iron metabolism - for a stressosome complex.
Topics: Bacterial Proteins; Cryoelectron Microscopy; Gene Expression Regulation, Bacterial; Iron; Oxygen; Vibrio vulnificus
PubMed: 35761021
DOI: 10.1038/s42003-022-03548-w -
Vibrio vulnificus PlpA facilitates necrotic host cell death induced by the pore forming MARTX toxin.Journal of Microbiology (Seoul, Korea) Feb 2022Opportunistic pathogen Vibrio vulnificus causes severe systemic infection in humans with high mortality. Although multiple exotoxins have been characterized in V....
Opportunistic pathogen Vibrio vulnificus causes severe systemic infection in humans with high mortality. Although multiple exotoxins have been characterized in V. vulnificus, their interactions and potential synergistic roles in pathogen-induced host cell death have not been investigated previously. By employing a series of multiple exotoxin deletion mutants, we investigated whether specific exotoxins of the pathogen functioned together to achieve severe and rapid necrotic cell death. Human epithelial cells treated with V. vulnificus with a plpA deletion background exhibited an unusually prolonged cell blebbing, suggesting the importance of PlpA, a phospholipase A, in rapid necrotic cell death by this pathogen. Additional deletion of the rtxA gene encoding the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin did not result in necrotic cell blebs. However, if the rtxA gene was engineered to produce an effector-free MARTX toxin, the cell blebbing was observed, indicating that the pore forming activity of the MARTX toxin is sufficient, but the MARTX toxin effector domains are not necessary, for the blebbing. When a recombinant PlpA was treated on the blebbed cells, the blebs were completely disrupted. Consistent with this, MARTX toxin-pendent rapid release of cytosolic lactate dehydrogenase was significantly delayed in the plpA deletion background. Mutations in other exotoxins such as elastase, cytolysin/hemolysin, and/or extracellular metalloprotease did not affect the bleb formation or disruption. Together, these findings indicate that the pore forming MARTX toxin and the phospholipase A, PlpA, cooperate sequentially to achieve rapid necrotic cell death by inducing cell blebbing and disrupting the blebs, respectively.
Topics: 3T3-L1 Cells; Animals; Bacterial Proteins; Bacterial Toxins; Cell Death; Exotoxins; HeLa Cells; Host-Pathogen Interactions; Humans; Mice; Phospholipases A2; Sequence Deletion; Vibrio Infections; Vibrio vulnificus; Virulence Factors
PubMed: 35102528
DOI: 10.1007/s12275-022-1448-x -
Molecular and Cellular Probes Apr 2021Researchers have developed multiple methods to characterize clinical and environmental strains of Vibrio vulnificus. The aim of our study was to use four assays to...
Researchers have developed multiple methods to characterize clinical and environmental strains of Vibrio vulnificus. The aim of our study was to use four assays to detect virulence factors in strains from infected patients and those from surface waters/sediments/oysters of South Carolina and the Gulf of Mexico. Vibrio vulnificus strains from clinical (n = 81) and environmental (n = 171) sources were tested using three real-time PCR methods designed to detect polymorphisms in the 16S rRNA, vcg and pilF genes and a phenotypic method, the ability to ferment D-mannitol. Although none of the tests correctly categorized all isolates, the differentiation between clinical and environmental isolates was similar for the pilF, vcgC/E and 16S rRNA assays, with sensitivities of 74.1-79.2% and specificities of 77.4-82.7%. The pilF and vcgC/E assays are comparable in efficacy to the widely used 16S rRNA method, while the D-mannitol fermentation test is less discriminatory (sensitivity = 77.8%, specificity = 61.4%). Overall percent agreement for the D-mannitol fermentation method was also lower (66.7%) than overall percent agreement for the 3 molecular assays (78.0%-80.2%). This study demonstrated, using a large, diverse group of Vibrio vulnificus isolates, that three assays could be used to distinguish most clinical vs environmental isolates; however, additional assays are needed to increase accuracy.
Topics: Animals; Bacterial Proteins; Bacterial Typing Techniques; Fermentation; Gene Expression; Humans; Mannitol; RNA, Ribosomal, 16S; Seafood; Shellfish; United States; Vibrio Infections; Vibrio vulnificus; Virulence; Water Microbiology
PubMed: 33453365
DOI: 10.1016/j.mcp.2021.101695 -
International Journal of Molecular... May 2020populates coastal waters around the world, where it exists freely or becomes concentrated in filter feeding mollusks. It also causes rapid and life-threatening sepsis... (Review)
Review
populates coastal waters around the world, where it exists freely or becomes concentrated in filter feeding mollusks. It also causes rapid and life-threatening sepsis and wound infections in humans. Of its many virulence factors, it is the capsule, composed of capsular polysaccharide (CPS), that plays a critical role in evasion of the host innate immune system by conferring antiphagocytic ability and resistance to complement-mediated killing. CPS may also provoke a portion of the host inflammatory cytokine response to this bacterium. CPS production is biochemically and genetically diverse among strains of , and the carbohydrate diversity of CPS is likely affected by horizontal gene transfer events that result in new combinations of biosynthetic genes. Phase variation between virulent encapsulated opaque colonial variants and attenuated translucent colonial variants, which have little or no CPS, is a common phenotype among strains of this species. One mechanism for generating acapsular variants likely involves homologous recombination between repeat sequences flanking the phosphatase gene within the Group 1 CPS biosynthetic and transport operon. A considerable number of environmental, genetic, and regulatory factors have now been identified that affect CPS gene expression and CPS production in this pathogen.
Topics: Antigens, Bacterial; Bacterial Capsules; Gene Expression; Gene Expression Regulation, Bacterial; Humans; Operon; Phenotype; Polysaccharides, Bacterial; Structure-Activity Relationship; Vibrio Infections; Vibrio vulnificus; Virulence; Virulence Factors
PubMed: 32380667
DOI: 10.3390/ijms21093259 -
Current Protocols in Microbiology Sep 2020Vibrio vulnificus, an emergent human pathogen, causes fulminant septicemia with a mortality rate of over 50%. Unlike for other pathogenic Vibrio species, the factors to...
Vibrio vulnificus, an emergent human pathogen, causes fulminant septicemia with a mortality rate of over 50%. Unlike for other pathogenic Vibrio species, the factors to conclusively indicate the virulence potential of V. vulnificus strains remain largely unknown. Understanding the pathogenesis of this bacterium at a molecular level is severely hindered by inefficiencies in transformation, for instance, due to the presence of a periplasmic nuclease, Vvn. Currently, successful transformation of V. vulnificus is nearly impossible due to lack of mobilizable plasmids for the bacterium, requiring (i) very high DNA concentrations, (ii) plasmid linearization, (iii) development of novel V. vulnificus-derived plasmids, or (iv) time-consuming conjugation-based methods. To overcome these limitations, we describe a rapid, efficient, and reproducible electroporation protocol to effectively transform widely available plasmids, with different copy numbers and antibiotic resistances, into phylogenetically distant strains of V. vulnificus. Cells are made competent in high concentrations of sucrose devoid of cations and recovered from electroporation using a high-salinity recovery medium. Compared to existing methods for transformation of V. vulnificus, significantly higher efficiencies are obtained using this improved protocol. Rapid and effective transformations can markedly improve molecular analyses of V. vulnificus leading to a greater understanding of its virulence potential. This is crucial to develop rapid detection methods which have the potential to prevent future outbreaks. The electroporation protocol described here may be particularly useful for optimizing transformation of other nuclease-producing bacteria. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Preparation of competent cells Basic Protocol 2: Transformation of cells by electroporation.
Topics: DNA Transformation Competence; Electroporation; Plasmids; Transformation, Bacterial; Vibrio vulnificus
PubMed: 32614522
DOI: 10.1002/cpmc.106 -
Journal of Neurovirology Feb 2019Vibrio vulnificus usually causes wound infection, gastroenteritis, and septicemia. However, it is a rare conditional pathogen causing meningoencephalitis. We report a...
Vibrio vulnificus usually causes wound infection, gastroenteritis, and septicemia. However, it is a rare conditional pathogen causing meningoencephalitis. We report a case of a young, immunocompromised man presenting with severe sepsis after exposure to sea water and consumption of seafood. The patient subsequently developed meningoencephalitis, and Vibrio vulnificus was isolated from his blood culture. The sequence was confirmed by Next-generation sequencing of a sample of cerebrospinal fluid, as well as from a bacteria culture. After the pathogen was detected, the patient was treated with ceftriaxone, doxycycline, and moxifloxacin for 6 weeks, which controlled his infection. In this case, we acquired his clinical and dynamic MRI presentations, which were never reported. Physicians should consider Vibrio vulnificus infections when they see a similar clinical course, brain CT and MRI findings, susceptibility factors and recent seafood ingestion or exposure to seawater. Due to high mortality, the early diagnosis and treatment of Vibrio vulnificus infections are crucial. Next-generation sequencing was found to be useful for diagnosis.
Topics: Adult; Anti-Bacterial Agents; Ceftriaxone; Doxycycline; Humans; Immunocompromised Host; Magnetic Resonance Imaging; Male; Meningoencephalitis; Moxifloxacin; Seafood; Seawater; Sepsis; Splenectomy; Thalassemia; Treatment Outcome; Vibrio vulnificus
PubMed: 30397825
DOI: 10.1007/s13365-018-0675-8 -
Microbiology Spectrum Feb 2022Vibrio vulnificus is a naturally occurring, potentially lethal pathogen found in coastal waters, fish, and shellfish. Sewage spills in coastal waters occur when...
Vibrio vulnificus is a naturally occurring, potentially lethal pathogen found in coastal waters, fish, and shellfish. Sewage spills in coastal waters occur when infrastructure fails due to severe storms or age, and may affect bacterial populations by altering nutrient levels. This study investigated effects of sewage on clonal and natural V. vulnificus populations in microcosms. Addition of 1% sewage to estuarine water caused the density of a pure culture of V. vulnificus CMCP6 and a natural V. vulnificus population to increase significantly, by two to three orders of magnitude, whether measured by quantitative PCR (qPCR) or culture and in batch and continuous cultures. Changes in the transcription of six virulence- and survival-associated genes in response to sewage were assessed using continuous culture. Exposure to sewage affected transcription of genes that may be associated with virulence, i.e., it modulated the oxidative stress response by altering superoxide dismutase transcription, significantly increasing transcription while repressing Sewage also repressed transcription of which encodes a sodium-phosphate cotransporter. Sewage had no effect on transcription or the putative virulence-associated genes or The effects of environmentally relevant levels of sewage on V. vulnificus populations and gene transcription suggest that sewage spills that impact warm coastal waters could lead to an increased risk of V. vulnificus infections. Vibrio vulnificus infections have profound impacts such as limb amputation and death for individuals with predisposing conditions. The warming climate is contributing to rising V. vulnificus prevalence in waters that were previously too cold to support high levels of the pathogen. Climate change is also expected to increase precipitation in many regions, which puts more pressure on wastewater infrastructure and will result in more frequent sewage spills. The finding that 1% wastewater in estuarine water leads to 100 to over 1,000-fold greater V. vulnificus concentrations suggests that human exposure to oysters and estuarine water could have greater health impacts in the future. Further, wastewater had a significant effect on gene transcription and has the potential to affect virulence during the initial environment-to-host transition.
Topics: Animals; Fishes; Gene Expression Regulation, Bacterial; Humans; Ostreidae; Seafood; Sewage; Transcription, Genetic; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 35171011
DOI: 10.1128/spectrum.01913-21 -
Biological & Pharmaceutical Bulletin 2022Vibrio vulnificus is a Gram-negative estuarine bacterium that causes infection in immuno-compromised patients, eels, and shrimp. V. vulnificus NCIMB2137, a...
Vibrio vulnificus is a Gram-negative estuarine bacterium that causes infection in immuno-compromised patients, eels, and shrimp. V. vulnificus NCIMB2137, a metalloprotease-negative strain isolated from a diseased eel, produces a 45-kDa chymotrypsin-like alkaline serine protease known as VvsA. The gene encoding vvsA also includes another gene, vvsB with an unknown function; however, it is assumed to be an essential molecular chaperone for the maturation of VvsA. In the present study, we used an in vitro cell-free translation system to examine the maturation pathway of VvsA. We individually expressed the vvsA and vvsB genes and detected their mRNAs. However, the sample produced from vvsA did not exhibit protease activity. A sodium dodecyl sulfate (SDS) analysis detected the VvsB protein, but not the VvsA protein. A Western blotting analysis using a histidine (His)-tag at the amino terminus of proteins also showed no protein production by vvsA. These results suggested the translation, but not the transcription of vvsA. Factors derived from Escherichia coli were used in the in vitro cell-free translation system employed in the present study. The operon of the serine protease gene containing vvsA and vvsB was expressed in E. coli. Although serine proteases were produced, they were cleaved at different sites and no active mature forms were detected. These results indicate that the operon encoding vvsA and vvsB is a gene constructed to be specifically expressed in V. vulnificus.
Topics: Humans; Vibrio vulnificus; Serine Proteases; Escherichia coli; Serine Endopeptidases
PubMed: 36328494
DOI: 10.1248/bpb.b22-00106 -
Transboundary and Emerging Diseases Dec 2018Vibrio vulnificus is a Gram-negative, curved, obligate halophilic marine bacterium that exclusively exists in coastal seawaters. Previous studies revealed that...
Vibrio vulnificus is a Gram-negative, curved, obligate halophilic marine bacterium that exclusively exists in coastal seawaters. Previous studies revealed that V. vulnificus is one of the most dangerous foodborne zoonotic pathogens for human beings. However, it remains unknown whether marine mammals can be infected by V. vulnificus. In May 2016, a captive spotted seal (Phoca largha) died due to septicemia induced by V. vulnificus. Upon post-mortem examination, V. vulnificus was isolated, identified, and named as BJ-PH01. Further analysis showed that BJ-PH01 belongs to biotype 1 and the Clinical genotype. Furthermore, we performed an epidemiological investigation of V. vulnificus in six aquariums in northern China. As a result, V. vulnificus was successfully isolated from all investigated aquariums. The positive rates ranged from 20% to 100% in each investigated aquarium. During the investigation, 12 strains of V. vulnificus were isolated, and all 12 isolates were classified into biotype 1. Eleven of the 12 isolates belonged to the Clinical genotype, and one isolate belonged to the Environmental genotype. All 12 isolated V. vulnificus strains showed limited antibiotic resistance. Overall, our work demonstrated that V. vulnificus is frequently distributed in aquariums, thus constituting a threat to captive marine mammals and to public health.
Topics: Animal Diseases; Animals; Animals, Zoo; China; Fishes; Genotype; Mammals; Public Health; Seals, Earless; Vibrio Infections; Vibrio vulnificus; Water Microbiology; Waterborne Diseases
PubMed: 30047566
DOI: 10.1111/tbed.12967