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Sample records for vibrio alginolyticus virulence

  1. Vibrio alginolyticus Associated Chronic Myringitis Acquired in Mediterranean Waters of Turkey

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    Burak Ekrem Citil

    2015-01-01

    Full Text Available Vibrio alginolyticus was originally classified as biotype 2 of Vibrio parahaemolyticus. Most clinical isolates are recovered from superficial wounds or the external ear infections. V. alginolyticus is acknowledged to be nearly nonpathogenic in humans. The reason for presence of V. alginolyticus’s virulence is uncertain. We describe a chronic myringitis case in a 47-year-old female due to V. alginolyticus. According to her anamnesis, it was detected that she had sea bathing history in Mugla Coast in Turkey. Pure isolation of V. alginolyticus was obtained from external auditory canal’s culture. Investigation and antimicrobial susceptibility of the isolate were performed by the automatized BD Phoenix system and Kirby-Bauer disk diffusion method, respectively. The bacteria were sensitive to all antibiotics. This case was presented to pay attention to Vibrio alginolyticus infections.

  2. AKTIVITAS ANTIBAKTERI EKSTRAK BUAH ADAS (Foeniculum vulgare, Mill PADA Vibrio harveyi DAN Vibrio alginolyticus Antibacterial Activity of Fennel (Foeniculum vulgare Mill Extract on Vibrio alginolyticus and Vibrio harveyi

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    Budianto Budianto

    2015-10-01

    Pada penelitian ini menggunakan ekstrak air dari buah adas untuk mengetahui aktivitas antibakteri terhadap Vibrio harveyi dan Vibrio alginolyticus dengan menggunakan metode uji Minimum Inhibitory Concentration (MIC dan difusi cakram kertas. Hasil yang diperoleh pada uji MIC, konsentrasi terkecil untuk menghambat pertumbuhan adalah 0,060 g/ml, untuk kedua spesies bakteri. Variasi perlakuan pada uji cakram kertas yaitu konsentrasi A (0,065 g/ml, B (0,070 g/ml, C (0,075 g/ml, D (0,080 g/ml, E (0,085 g/ml, F (0,090 g/ml dan kontrol (0,000 g/ml, hasil yang diperoleh adalah konsentrasi 0,090 g/ml memiliki diameter zona hambat tertinggi sebesar 11,17 ± 0,5 mm (V. harveyi dan 12,53 ± 1,14 mm (V. alginolyticus, sehingga dapat disimpulkan bahwa buah adas (F. vulgare Mill memiliki peranan ekologi yang sangat penting sebagai bahan pengobatan alternatif dalam pengendalian penyebaran penyakit Vibriosis yang disebabkan oleh V. harveyi dan V. alginolyticus. Kata kunci: Foeniculum vulgare Mill, Vibrio harveyi, Vibrio alginolyticus, uji MIC dan difusi cakram kertas

  3. Complete genome sequence of a giant Vibrio phage ValKK3 infecting Vibrio alginolyticus

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    Tamrin M. Lal

    2016-06-01

    Full Text Available This paper describes the complete sequence of a giant lytic marine myophage, Vibrio phage ValKK3 that is specific to Vibrio alginolyticus ATCC® 17749™. Vibrio phage ValKK3 was subjected to whole genome sequencing on MiSeq sequencing platform and annotated using Blast2Go. The complete sequence of ValKK3 genome was deposited in DBBJ/EMBL/GenBank under accession number KP671755.

  4. Complete genome sequence of a giant Vibrio phage ValKK3 infecting Vibrio alginolyticus.

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    Lal, Tamrin M; Sano, Motohiko; Hatai, Kishio; Ransangan, Julian

    2016-06-01

    This paper describes the complete sequence of a giant lytic marine myophage, Vibrio phage ValKK3 that is specific to Vibrio alginolyticus ATCC(®) 17749™. Vibrio phage ValKK3 was subjected to whole genome sequencing on MiSeq sequencing platform and annotated using Blast2Go. The complete sequence of ValKK3 genome was deposited in DBBJ/EMBL/GenBank under accession number KP671755.

  5. First characterization of bacterial pathogen, Vibrio alginolyticus, for Porites andrewsi White syndrome in the South China Sea.

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    Xie Zhenyu

    Full Text Available BACKGROUND: White syndrome, a term for scleractinian coral disease with progressive tissue loss, is known to cause depressed growth and increased morality of coral reefs in the major oceans around the world, and the occurrence of this disease has been frequently reported in the past few decades. Investigations during April to September in both 2010 and 2011 identified widespread Porites andrewsi White syndrome (PAWS in Xisha Archipelago, South China Sea. However, the causes and etiology of PAWS have been unknown. METHODOLOGY/PRINCIPAL FINDINGS: A transmission experiment was performed on P. andrewsi in the Qilianyu Subgroup (QLY. The results showed that there was a significant (P ≤ 0.05 difference between test and control groups after 28 days if the invalid replicates were excluded. Rates of tissue loss ranged from 0.90-10.76 cm(2 d(-1 with a mean of 5.40 ± 3.34 cm(2 d(-1 (mean ± SD. Bacterial strains were isolated from the PAWS corals at the disease outbreak sites in QLY of the Xisha Archipelago, South China Sea, and included in laboratory-based infection trials to satisfy Koch's postulates for establishing causality. Following exposure to bacterial concentrations of 10(5 cells mL(-1, the infected colonies exhibited similar signs to those observed in the field. Using phylogenetic 16S rRNA gene analysis, classical phenotypic trait comparison, Biolog automatic identification system, MALDI-TOF mass spectrometry and MALDI Biotyper method, two pathogenic strains were identified as Vibrio alginolyticus . CONCLUSION/SIGNIFICANCE: This is the first report of V. alginolyticus as a pathogenic agent of PAWS in the South China Sea. Our results point out an urgent need to develop sensitive detection methods for V. alginolyticus virulence strains and robust diagnostics for coral disease caused by this and Vibrio pathogenic bacterium in the South China Sea.

  6. First characterization of bacterial pathogen, Vibrio alginolyticus, for Porites andrewsi White syndrome in the South China Sea.

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    Zhenyu, Xie; Shaowen, Ke; Chaoqun, Hu; Zhixiong, Zhu; Shifeng, Wang; Yongcan, Zhou

    2013-01-01

    White syndrome, a term for scleractinian coral disease with progressive tissue loss, is known to cause depressed growth and increased morality of coral reefs in the major oceans around the world, and the occurrence of this disease has been frequently reported in the past few decades. Investigations during April to September in both 2010 and 2011 identified widespread Porites andrewsi White syndrome (PAWS) in Xisha Archipelago, South China Sea. However, the causes and etiology of PAWS have been unknown. A transmission experiment was performed on P. andrewsi in the Qilianyu Subgroup (QLY). The results showed that there was a significant (P ≤ 0.05) difference between test and control groups after 28 days if the invalid replicates were excluded. Rates of tissue loss ranged from 0.90-10.76 cm(2) d(-1) with a mean of 5.40 ± 3.34 cm(2) d(-1) (mean ± SD). Bacterial strains were isolated from the PAWS corals at the disease outbreak sites in QLY of the Xisha Archipelago, South China Sea, and included in laboratory-based infection trials to satisfy Koch's postulates for establishing causality. Following exposure to bacterial concentrations of 10(5) cells mL(-1), the infected colonies exhibited similar signs to those observed in the field. Using phylogenetic 16S rRNA gene analysis, classical phenotypic trait comparison, Biolog automatic identification system, MALDI-TOF mass spectrometry and MALDI Biotyper method, two pathogenic strains were identified as Vibrio alginolyticus . This is the first report of V. alginolyticus as a pathogenic agent of PAWS in the South China Sea. Our results point out an urgent need to develop sensitive detection methods for V. alginolyticus virulence strains and robust diagnostics for coral disease caused by this and Vibrio pathogenic bacterium in the South China Sea.

  7. MicroRNA-100 is involved in shrimp immune response to white spot syndrome virus (WSSV) and Vibrio alginolyticus infection.

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    Wang, Zhi; Zhu, Fei

    2017-02-09

    In this study, we discovered that shrimp miR-100 was up-regulated at 24 h after WSSV or Vibrio alginolyticus infection, confirming its participation in the innate immune system of shrimp. The anti-miRNA oligonucleotide (AMO-miR-100) was applied to inhibit the expression of miR-100. After AMO-miR-100 treatment, the shrimp was challenged with WSSV or V. alginolyticus. The knockdown of miR-100 expression decreased the mortality of WSSV-infected shrimp from 24 h to 72 h post-infection and enhanced the mortality of V. alginolyticus-infected shrimp significantly. The knockdown of miR-100 affected phenoloxidase (PO) activity, superoxide dismutase (SOD) activity and total hemocyte count (THC) after the infection with WSSV or V. alginolyticus, indicating a regulative role of miR-100 in the immune potential of shrimp in the response to WSSV or V. alginolyticus infection. The knockdown of miR-100 induced the apoptosis of shrimp hemocytes, and V. alginolyticus + AMO-miR-100 treatment caused more hemocyte apoptosis than V. alginolyticus treatment. The miR-100 influenced also the morphology of shrimp hemocytes and regulated the phagocytosis of WSSV or V. alginolyticus. Thus, we concluded that miR-100 may promote the anti-Vibrio immune response of shrimp through regulating apoptosis, phagocytosis and PO activity and affects the progression of WSSV infection at a certain level.

  8. Marine Lactobacillus pentosus H16 protects Artemia franciscana from Vibrio alginolyticus pathogenic effects.

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    Garcés, M E; Sequeiros, C; Olivera, N L

    2015-02-10

    Vibrio alginolyticus is an opportunistic pathogen which may affect different aquatic organisms. The aim of this study was to assess the probiotic properties and the protective mode of action of Lactobacillus pentosus H16 against V. alginolyticus 03/8525, through in vitro and in vivo studies using Artemia franciscana (hereafter Artemia). This strain showed antimicrobial activity against V. alginolyticus 03/8525 and Aeromonas salmonicida subsp. salmonicida ATCC33658 possibly related to lactobacilli organic acid production. It was able to survive at high rainbow trout bile concentrations and showed high selective adhesion to rainbow trout mucus (1.2×10(5)±8.0×10(3) cells cm(-2)). H16 outcompeted V. alginolyticus 03/8525 and A. salmonicida subsp. salmonicida ATCC33658, greatly reducing their adherence to rainbow trout mucus (64.8 and 74.1%, respectively). Moreover, H16 produced a cell-bound biosurfactant which caused an important decrease in the surface tension. H16 also protected Artemia nauplii against mortality when it was administered previous to V. alginolyticus 03/8525 inoculation. Furthermore, H16 bioencapsulated in Artemia, suggesting that it is possible to use live carriers in its administration. We conclude that the ability of L. pentosus H16 to selectively adhere to mucosal surfaces and produce cell-bound biosurfactants, displacing pathogenic strains, in addition to its antimicrobial activity, confer H16 competitive advantages against pathogens as demonstrated in in vivo challenge experiments. Thus, L. pentosus H16, a marine bacterium from the intestinal tract of hake, is an interesting probiotic for Artemia culture and also has the potential to prevent vibriosis in other aquaculture activities such as larvae culture and fish farming.

  9. Differential expression of microRNAs in shrimp Marsupenaeus japonicus in response to Vibrio alginolyticus infection.

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    Zhu, Fei; Wang, Zhi; Sun, Bao-Zhen

    2016-02-01

    Till date numerous microRNAs (miRNAs) have been discovered from various organisms, including mammals, plants, insects, nematodes and viruses. They are known to have antiviral functions in crustaceans such as shrimp Marsupenaeus japonicas. However, little is known about the role of miRNAs against bacterial infection in this shrimp caused by Vibrio alginolyticus. We performed small RNA sequencing to characterize the differentially expressed microRNAs in V. alginolyticus challenged shrimp, in comparison to that in control uninfected shrimp, at 24 h and 48 h. In total, 55 host miRNAs were differentially expressed in response to the infection and most of these were downregulated at both the time-points. TargetScan and miRanda algorithms showed that the target genes of these down-regulated miRNAs were related to innate immune functions such as production of phenoloxidase enzyme, apoptosis and phagocytosis. Further, gene ontology analysis revealed that many immune signaling pathways were mediated by these miRNAs. This study is one of the earliest attempts at characterizing shrimp miRNAs that respond to V. alginolyticus infection, and will help unravel the miRNA pathways involved in antibacterial action in shrimp. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The TCA Pathway is an Important Player in the Regulatory Network Governing Vibrio alginolyticus Adhesion Under Adversity.

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    Huang, Lixing; Huang, Li; Yan, Qingpi; Qin, Yingxue; Ma, Ying; Lin, Mao; Xu, Xiaojin; Zheng, Jiang

    2016-01-01

    Adhesion is a critical step in the initial stage of Vibrio alginolyticus infection; therefore, it is important to understand the underlying mechanisms governing the adhesion of V. alginolyticus and determine if environmental factors have any effect. A greater understanding of this process may assist in developing preventive measures for reducing infection. In our previous research, we presented the first RNA-seq data from V. alginolyticus cultured under stress conditions that resulted in reduced adhesion. Based on the RNA-seq data, we found that the Tricarboxylic acid cycle (TCA pathway) might be closely related to adhesion. Environmental interactions with the TCA pathway might alter adhesion. To validate this, bioinformatics analysis, quantitative Real-Time PCR (qPCR), RNAi, and in vitro adhesion assays were performed, while V. alginolyticus was treated with various stresses including temperature, pH, salinity, and starvation. The expression of genes involved in the TCA pathway was confirmed by qPCR, which reinforced the reliability of the sequencing data. Silencing of these genes was capable of reducing the adhesion ability of V. alginolyticus. Adhesion of V. alginolyticus is influenced substantially by environmental factors and the TCA pathway is sensitive to some environmental stresses, especially changes in pH and starvation. Our results indicated that (1) the TCA pathway plays a key role in V. alginolyticus adhesion: (2) the TCA pathway is sensitive to environmental stresses.

  11. The TCA pathway is an important player in the regulatory network governing Vibrio alginolyticus adhesion under adversity

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    Lixing eHuang

    2016-02-01

    Full Text Available Adhesion is a critical step in the initial stage of Vibrio alginolyticus infection; therefore, it is important to understand the underlying mechanisms governing the adhesion of V. alginolyticus and determine if environmental factors have any effect. A greater understanding of this process may assist in developing preventive measures for reducing infection. In our previous research, we presented the first RNA-seq data from V. alginolyticus cultured under stress conditions that resulted in reduced adhesion. Based on the RNA-seq data, we found that the Tricarboxylic acid cycle (TCA pathway might be closely related to adhesion. Environmental interactions with the TCA pathway might alter adhesion. To validate this, bioinformatics analysis, qPCR, RNAi and in vitro adhesion assays were performed, while V. alginolyticus was treated with various stresses including temperature, pH, salinity and starvation. The expression of genes involved in the TCA pathway was confirmed by qPCR, which reinforced the reliability of the sequencing data. Silencing of these genes was capable of reducing the adhesion ability of V. alginolyticus. Adhesion of V. alginolyticus is influenced substantially by environmental factors and the TCA pathway is sensitive to some environmental stresses, especially changes in pH and starvation. Our results indicated that 1 the TCA pathway plays a key role in V. alginolyticus adhesion: 2 the TCA pathway is sensitive to environmental stresses.

  12. Vaccination Enhances Early Immune Responses in White Shrimp Litopenaeus vannamei after Secondary Exposure to Vibrio alginolyticus

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    Lin, Yong-Chin; Chen, Jiann-Chu; Morni, Wan Zabidii W.; Putra, Dedi Fazriansyah; Huang, Chien-Lun; Li, Chang-Che; Hsieh, Jen-Fang

    2013-01-01

    Background Recent work suggested that the presence of specific memory or some form of adaptive immunity occurs in insects and shrimp. Hypervariable pattern recognition molecules, known as Down syndrome cell adhesion molecules, are able to mount specific recognition, and immune priming in invertebrates. In the present study, we attempted to understand the immune response pattern of white shrimp Litopenaeus vannamei which received primary (PE) and secondary exposure (SE) to Vibrio alginolyticus. Methodology Immune parameters and proliferation of haematopoietic tissues (HPTs) of shrimp which had received PE and SE to V. alginolyticus were measured. In the PE trial, the immune parameters and proliferation of HPTs of shrimp that received heat-killed V. alginolyticus (HVa) and formalin-inactivated V. alginolyticus (FVa) were measured. Mortality, immune parameters and proliferation of HPTs of 7-day-HVa-PE shrimp (shrimp that received primary exposure to HVa after 7 days) and 7-day-FVa-PE shrimp (shrimp that received primary exposure to FVa after 7 days) following SE to live V. alginolyticus (LVa) were measured. Phagocytic activity and clearance efficiency were examined for the 7∼35-day-HVa-PE and FVa-PE shrimp. Results HVa-receiving shrimp showed an earlier increase in the immune response on day 1, whereas FVa-receiving shrimp showed a late increase in the immune response on day 5. The 7-day-FVa-PE shrimp showed enhancement of immunity when encountering SE to LVa, whereas 7-day-HVa-PE shrimp showed a minor enhancement in immunity. 7-day-FVa-PE shrimp showed higher proliferation and an HPT mitotic index. Both phagocytic activity and clearance maintained higher for both HVa-PE and FVa-PE shrimp after 28 days. Conclusions HVa- and FVa-receiving shrimp showed the bacteria agglutinated prior to being phagocytised. FVa functions as a vaccine, whereas HVa functions as an inducer and can be used as an immune adjuvant. A combined mixture of FVa and HVa can serve as a

  13. LvDJ-1 plays an important role in resistance against Vibrio alginolyticus in Litopenaeus vannamei.

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    Huang, Mingzhu; Liu, Yuan; Xie, Chenying; Wang, Wei-Na

    2015-05-01

    DJ-1 was first identified as an oncogene that transformed mouse NIH3T3 cells in cooperation with activated Ras. It has since exhibited a variety of functions in a range of organisms. In this study, the DJ-1 gene in Litopenaeus vannamei (LvDJ-1) was identified and characterized. A recombinant protein LvDJ-1 was produced in Pichia pastoris. LvDJ-1 expression in vivo was knocked down by dsRNA-mediated RNA interference (RNAi), which led to significantly decreased levels of LvDJ-1 mRNA and protein. When the L. vannamei were challenged with RNAi and Vibrio alginolyticus, the transcription and expression of copper zinc superoxide dismutase (LvCZSOD) in the hepatopancreas were dramatically lower in shrimp with knocked down LvDJ-1 than in controls. Transcription and expression of P53 (LvP53) were significantly higher in shrimp lacking LvDJ-1 than in controls. Hepatopancreas samples were analyzed using real time polymerase chain reaction and Western blot. Moreover, blood samples from the shrimp, assessed with flow cytometry, showed significant increases in respiratory burst and apoptosis in those lacking LvDJ-1 compared to the controls. Cumulative mortality in the shrimp lacking LvDJ-1 was significantly different from that in the control group after challenge with V. alginolyticus. Altogether, the results prove that LvDJ-1 regulates apoptosis and antioxidant activity, and that these functions play an important role in L. vannamei resistance against V. alginolyticus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. MicroRNA-100 is involved in shrimp immune response to white spot syndrome virus (WSSV) and Vibrio alginolyticus infection

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    Zhi Wang; Fei Zhu

    2017-01-01

    In this study, we discovered that shrimp miR-100 was up-regulated at 24?h after WSSV or Vibrio alginolyticus infection, confirming its participation in the innate immune system of shrimp. The anti-miRNA oligonucleotide (AMO-miR-100) was applied to inhibit the expression of miR-100. After AMO-miR-100 treatment, the shrimp was challenged with WSSV or V. alginolyticus. The knockdown of miR-100 expression decreased the mortality of WSSV-infected shrimp from 24?h to 72?h post-infection and enhance...

  15. Isolation and characterization of specific bacteriophage Va1 to Vibrio alginolyticus

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    Carla Fernández Espinel

    2017-04-01

    Full Text Available Vibrio alginolyticus is associated with diseases in aquaculture. The misuse of antibiotics has led to the search for alternatives in the treatment of bacterial diseases, among them the application of bacteriophages that infect and destroy bacteria selectively. In this way, a highly lytic V. alginolyticus bacteriophage, termed Va1, was isolated, with the aim to evaluate its physical chemical parameters. For this purpose, different temperature, pH, chloroform exposure and host range conditions were evaluated. The temperature stability of phage Va1 showed higher titers at 20 and 30 °C decreasing from 40 °C. With respect to pH, the highest titers for the bacteriophage were between 5 and 8, and chloroform exposure reduced viability of the Va1 phage by 25%. The one-step curve determined that the latency period and the burst size were 20 minutes and 192 PFU / infective center respectively. Under the transmission electron microscope, the Va1 phage showed an icosahedral head and a non-contractile tail, belonging to the Podoviridae family. In conclusion, Va1 phage presents potential characteristics for use in phage therapy.

  16. Genetic heterogeneity among Vibrio alginolyticus strains, and design of a PCR-based identification method using gyrB gene sequence.

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    Bunpa, Supansa; Nishibuchi, Mitsuaki; Thawonsuwan, Jumroensri; Sermwittayawong, Natthawan

    2017-10-10

    Vibrio alginolyticus, a pathogen among humans and marine animals, is ubiquitous in marine environments. The aims of this study were to analyze the relationships between genetic diversity and origins, and to develop new primers based on the gyrB sequence to identify V. alginolyticus isolated from various sources. To determine the genetic diversity of this bacterium, an arbitrarily primed polymerase chain reaction (AP-PCR) technique was performed on 36 strains of V. alginolyticus isolated from diarrhea patients and from diseased marine animals and environments in southern Thailand. The results showed distinct DNA fingerprints of all strains, indicating that they are genetically heterogeneous. For species-specific identification of V. alginolyticus, primers targeting the gyrB gene of V. alginolyticus were developed. Thirty reference Vibrio spp., 13 non-Vibrio spp., and 160 strains of V. alginolyticus isolated from various sources in southern Thailand were used to evaluate the specificity of these primers. Our results showed that the gyrB primers could specifically identify V. alginolyticus from all sample types. In addition, the detection limit of the PCR was at least 95 pg of DNA template. Therefore, we concluded that the newly designed gyrB primers are rapid, highly sensitive, and specific to identify V. alginolyticus isolated from various sources.

  17. Spirulina elicits the activation of innate immunity and increases resistance against Vibrio alginolyticus in shrimp.

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    Chen, Yu-Yuan; Chen, Jiann-Chu; Tayag, Carina Miranda; Li, Hui-Fang; Putra, Dedi Fazriansyah; Kuo, Yi-Hsuan; Bai, Jia-Chin; Chang, Yu-Hsuan

    2016-08-01

    The effect of Spirulina dried powder (SDP) on the immune response of white shrimp Litopenaeus vannamei was studied in vitro and in vivo. Incubating shrimp haemocytes in 0.5 mg ml(-1) SDP caused the degranulation of haemocytes and a reduction in the percentage of large cells within 30 min. Shrimp haemocytes incubated in 1 mg ml(-1) SDP significantly increased their phenoloxidase (PO) activity, serine proteinase activity, and respiratory burst activity (RB, release of superoxide anion). A recombinant protein of lipopolysaccharide and β-1,3-glucan binding protein (LGBP) of the white shrimp was produced, named rLvLGBP, and examined for its binding with SDP. An ELISA binding assay showed that rLvLGBP binds to SDP with a dissociation constant of 0.0507 μM. In another experiment, shrimp fed diets containing SDP at 0 (control), 30, and 60 g kg(-1) after four weeks were examined for LGBP transcript level and lysozyme activity, as well as phagocytic activity, clearance efficiency, and resistance to Vibrio alginolyticus. These parameters were significantly higher in shrimp receiving diets containing SDP at 60 g kg(-1) or 30 g kg(-1) than in controls. In conclusion, shrimp haemocytes receiving SDP provoked the activation of innate immunity as evidenced by the recognition and binding of LGBP, degranulation of haemocytes, reduction in the percentage of large cells, increases in PO activity, serine proteinase activity, superoxide anion levels, and up-regulated LGBP transcript levels. Shrimp receiving diets containing SDP had increased lysozyme activity and resistance against V. alginolyticus infection. This study showed the mechanism underlying the immunostimulatory action of Spirulina and its immune response in shrimp. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Effect of dietary supplementation with butyrate and probiotic on the survival of Pacific white shrimp after challenge with Vibrio alginolyticus

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    Norha Constanza Bolívar Ramírez

    Full Text Available ABSTRACT This study evaluated the performance, immunology, and survival of the Pacific white shrimp Litopenaeus vannamei to experimental challenge to Vibrio alginolyticus based on the use of the probiotic Lactobacillus plantarum and the combined use of probiotic and butyrate. Four different diets resulted from the addition of additives: butyrate, probiotic, butyrate + probiotic, and control (no additives. The attractiveness of the diets was assessed by the percentage of positive choices and rejections, using a dual-choice Y-maze format aquarium. The shrimps were fed during four weeks and performance parameters, intestinal microbiota, and immunological parameters were all evaluated. Subsequently, the shrimps were challenged with V. alginolyticus and after 48 h, survival and immunological parameters were evaluated. The results showed increased attractiveness and intake, but only with diets supplemented with sodium butyrate. However, other diets were not rejected. No difference in performance or immunological parameters was observed among the different diets. Also, among the treatments, no difference in Vibrio spp., or total heterotrophic bacteria counts, was found in the intestinal tract. However, the lactic acid bacteria count was higher in the intestinal tract of shrimps fed diets supplemented with probiotic. After bacterial challenge, shrimp fed all diets had a greater survival when compared with the control group. Lactobacillus plantarum and sodium butyrate increase the resistance of shrimp to infection with V. alginolyticus, but do so without affecting performance, immunological parameters, or Vibrio spp., and total heterotrophic bacteria counts in the intestinal tract.

  19. Molecular characterization and function of the Prohibitin2 gene in Litopenaeus vannamei responses to Vibrio alginolyticus.

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    Gu, Mei-Mei; Kong, Jing-Rong; Di-Huang; Peng, Ting; Xie, Chen-Ying; Yang, Kai-Yuan; Liu, Yuan; Wang, Wei-Na

    2017-02-01

    Prohibitin2 (PHB2), a potential tumor suppressor protein, plays important roles in inhibition of cell cycle progression, transcriptional regulation, apoptosis and the mitochondrial respiratory chain. To explore its potential roles in crustaceans' immune responses we have identified and characterized LvPHB2, a 891 bp gene encoding a 297 amino acids protein in the shrimp Litopenaeus vannamei. Expression analyses showed that LvPHB2 is expressed in all examined tissues, and largely present in cytoplasm, correlating with its known anti-oxidation function in mitochondria. Luciferase reporter assays showed that over-expression of LvPHB2 could activate the p53 pathway, indicating that it might participate in apoptosis regulation. Quantitative real-time PCR revealed that infection with Vibrio alginolyticus induces its up-regulation in hepatopancreas. Moreover, RNAi knock-down of LvPHB2 in vivo raises mortality rates of L. vannamei infected by V. alginolyticus, and affects expression of STAT3, Caspase3 and p53 genes. We found significantly higher reactive oxygen species production, DNA damage and apoptosis rates in LvPHB2-silenced shrimp challenged with V. alginolyticus than in controls injected with a Green Fluorescent Protein-silencing construct. Our results suggest that LvPHB2 plays a vital role in shrimp responses to V. alginolyticus infection through its participation in regulation of oxidants and apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Enhancements of non-specific immune response in Mugil cephlus by seaweed extract against Vibrio alginolyticus (BRTR07)

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    Rajasekar Thirunavukkarasu; Priyadharshini Pandiyan; Deivasigamani Balaraman; Ilamathi Jayaraman; Kumaran Subaramaniyan; Edward Gnana Jothi George

    2015-01-01

    Objective: To focus on the growth rate and feed utilization of fish by using trash fish feeds supplement with marine seaweeds. Methods: Selected seaweed was extracted using hot-water and its extract was mixed with trash fish feed at different concentrations (0.5%, 1% and 2% for 1-30 days) and the nonspecific immune response in fish was studied and challenged with Vibrio alginolyticus at 1 × 106 CFU/fish. The hot-water extract of seaweeds was analysed by gas chromatography-mass ...

  1. Enhancements of non-specific immune response in Mugil cephlus by seaweed extract against Vibrio alginolyticus (BRTR07

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    Rajasekar Thirunavukkarasu

    2015-10-01

    Full Text Available Objective: To focus on the growth rate and feed utilization of fish by using trash fish feeds supplement with marine seaweeds. Methods: Selected seaweed was extracted using hot-water and its extract was mixed with trash fish feed at different concentrations (0.5%, 1% and 2% for 1-30 days and the nonspecific immune response in fish was studied and challenged with Vibrio alginolyticus at 1 × 106 CFU/fish. The hot-water extract of seaweeds was analysed by gas chromatography-mass spectrometry. Results: The average body weight (5.320 ± 0.018, percent weight gain (227.66 ± 0.28, specific growth rate (2.080 ± 0.015, hepatosomatic index (1.197 ± 0.00 and viscerosomatic index (4.421 ± 0.150 were significantly increased in the fish feed with seaweed containing 5% of Sargassum wightii (S. wightii when compared with other seaweeds and control diet. Hotwater extract of S. wightii (1% was significantly enhanced the immune response in fish when compared with other diets (0.5% and 2%. S. wightii showed good immunostimulation properties. Gas chromatography-mass spectrometry result showed that the hot-water extract of S. wightii seaweed contained fatty acids. Conclusions: Trash fish feed will reduce the production cost and also provide evidence that aqueous leaf extract of S. wightii (1% was added to a formulated fish diet which could activate the non-specific immune response and disease resistance against Vibrio alginolyticus in Mugil cephalus.

  2. Fucoidan effectively provokes the innate immunity of white shrimp Litopenaeus vannamei and its resistance against experimental Vibrio alginolyticus infection.

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    Kitikiew, Suwaree; Chen, Jiann-Chu; Putra, Dedi Fazriansyah; Lin, Yong-Chin; Yeh, Su-Tuen; Liou, Chyng-Hwa

    2013-01-01

    In this study, we examined the effect of fucoidan on the immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus infection. Fucoidan induced degranulation, caused changes in the cell morphology, and increased activation of prophenoloxidase (proPO) and the production of superoxide anions in vitro. Shrimp that received fucoidan via immersion at 100, 200, and 400 mg l(-1) after 3 h showed haemocyte proliferation and a higher mitotic index of haematopoietic tissue. In another experiment, the haemocyte count, phenoloxidase (PO) activity, and respiratory bursts (RBs) were examined after the shrimp had been fed diets containing fucoidan at 0 (control), 0.5, 1.0, and 2.0 g kg(-1) for 7-21 days. Results indicated that these parameters directly increased with time. The immune parameters of shrimp fed the 1.0 g kg(-1) diet were significantly higher than those of shrimp fed the 2.0 g kg(-1) diet after 14 and 21 days. Phagocytic activity and the clearance efficiency against V. alginolyticus were significantly higher in shrimp fed the 1.0 g kg(-1) diet compared to those of shrimp fed the 0, 0.5 and 2.0 g kg(-1) diets. In a separate experiment, shrimp that had been fed diets containing fucoidan for 21 days were challenged with V. alginolyticus at 10(6) colony-forming units shrimp(-1). Survival rates of shrimp fed the 1.0 and 2.0 g kg(-1) diets were significantly higher than those of shrimp fed the 0 and 0.5 g kg(-1) diets for 96-120 h. We concluded that fucoidan provokes innate immunity of shrimp as evidenced by haemocyte degranulation, proPO activation, and the mitotic index of haematopoietic tissue, and that dietary administration of fucoidan at 1.0 g kg(-1) enhanced the immune response of shrimp and their resistance against V. alginolyticus infection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Prevalence of mobile genetic elements and transposase genes in Vibrio alginolyticus from the southern coastal region of China and their role in horizontal gene transfer.

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    Luo, Peng; Jiang, Haiying; Wang, Yanhong; Su, Ting; Hu, Chaoqun; Ren, Chunhua; Jiang, Xiao

    2012-12-01

    Vibrio alginolyticus has high genetic diversity, but little is known about the means by which it has been acquired. In this study, the distributions of mobile genetic elements (MGEs), including integrating conjugative elements (ICEs), superintegron-like cassettes (SICs), insertion sequences (ISs), and two types of transposase genes (valT1 and valT2), in 192 strains of V. alginolyticus were investigated. ICE, SIC, and IS elements, valT1, and valT2 were detected in 8.9%, 13.0%, 4.7%, 9.4%, and 2.6% of the strains, respectively. Blast searches and phylogenetic analysis of the acquired sequences of the ICE, SIC, IS elements and transposase genes showed that the corresponding homologues were bacterial and derived from extensive sources. The high prevalences of these MGEs in V. alginolyticus implied the extensive and frequent exchange of genes with environmental bacteria and that these elements strongly contribute to the genetic and phenotypic diversity of the bacterium. To our knowledge, this is the first report of V. alginolyticus harboring ICE and SIC elements.

  4. Vibrio parahaemolyticus- and V. alginolyticus-associated meningo-encephalitis in a bottlenose dolphin (Tursiops truncatus) from the Adriatic coast of Italy.

    Science.gov (United States)

    Di Renzo, Ludovica; Di Francesco, Gabriella; Profico, Chiara; Di Francesco, Cristina E; Ferri, Nicola; Averaimo, Daniela; Di Guardo, Giovanni

    2017-12-01

    A case of Vibrio parahaemolyticus- and V. alginolyticus-associated meningo-encephalitis in a bottlenose dolphin (Tursiops truncatus) found stranded along the Adriatic coast of Italy in 2016 is herein reported, along with a minireview on V. parahaemolyticus and V. alginolyticus infections in aquatic mammals. Macroscopically, two abscesses were found in the dolphin's forebrain, along with an extensive, bilateral, parasitic broncho-pneumonia. Histologically, a suppurative-to-pyogranulomatous meningo-encephalitis involved the brain but not the cerebellum. Microbiological investigations yielded isolation of V. parahaemolyticus and V. alginolyticus from the aforementioned abscesses and from the brain parenchyma, respectively, with simultaneous recovery of Shewanella algae from the heart and of Photobacterium damselae from a blowhole swab. Although V. parahaemolyticus and V. alginolyticus, which are widely distributed across marine ecosystems worldwide, likely played a role in the development of the suppurative meningo-encephalitis in this dolphin, we are not aware of previous isolations of any of these two bacteria neither from cetacean brain lesions, nor from abscesses in aquatic mammals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Sigma E regulators control hemolytic activity and virulence in a shrimp pathogenic Vibrio harveyi.

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    Pimonsri Rattanama

    Full Text Available Members of the genus Vibrio are important marine and aquaculture pathogens. Hemolytic activity has been identified as a virulence factor in many pathogenic vibrios including V. cholerae, V. parahaemolyticus, V. alginolyticus, V. harveyi and V. vulnificus. We have used transposon mutagenesis to identify genes involved in the hemolytic activity of shrimp-pathogenic V. harveyi strain PSU3316. Out of 1,764 mutants screened, five mutants showed reduced hemolytic activity on sheep blood agar and exhibited virulence attenuation in shrimp (Litopenaeus vannamei. Mutants were identified by comparing transposon junction sequences to a draft of assembly of the PSU3316 genome. Surprisingly none of the disrupted open reading frames or gene neighborhoods contained genes annotated as hemolysins. The gene encoding RseB, a negative regulator of the sigma factor (σ(E, was interrupted in 2 out of 5 transposon mutants, in addition, the transcription factor CytR, a threonine synthetase, and an efflux-associated cytoplasmic protein were also identified. Knockout mutations introduced into the rpoE operon at the rseB gene exhibited low hemolytic activity in sheep blood agar, and were 3-to 7-fold attenuated for colonization in shrimp. Comparison of whole cell extracted proteins in the rseB mutant (PSU4030 to the wild-type by 2-D gel electrophoresis revealed 6 differentially expressed proteins, including two down-regulated porins (OmpC-like and OmpN and an upregulated protease (DegQ which have been associated with σ(E in other organisms. Our study is the first report linking hemolytic activity to the σ(E regulators in pathogenic Vibrio species and suggests expression of this virulence-linked phenotype is governed by multiple regulatory pathways within the V. harveyi.

  6. Isolation and Characterization of Bacteria Colonizing Acartia tonsa Copepod Eggs and Displaying Antagonist Effects against Vibrio anguillarum, Vibrio alginolyticus and Other Pathogenic Strains

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    Mahammed Zidour

    2017-10-01

    Full Text Available Copepods represent a major source of food for many aquatic species of commercial interest for aquaculture such as mysis shrimp and early stages of fishes. For the purpose of this study, the culturable mesophilic bacterial flora colonizing Acartia tonsa copepod eggs was isolated and identified. A total of 175 isolates were characterized based on their morphological and biochemical traits. The majority of these isolates (70% were Gram-negative bacteria. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS was used for rapid identification of bacterial isolates. Here, 58% of isolates were successfully identified at the genus level and among them, 54% were identified at the species level. These isolates belong to 12 different genera and 29 species. Five strains, identified as Bacillus pumilus, named 18 COPS, 35A COPS, 35R COPS, 38 COPS, and 40A COPS, showed strong antagonisms against several potential fish pathogens including Vibrio alginolyticus, V. anguillarum, Listeria monocytogenes, and Staphylococcus aureus. Furthermore, using a differential approach, we show that the antimicrobial activity of the 35R COPS strain is linked primarily to the production of antimicrobial compounds of the amicoumacin family, as demonstrated by the specific UV-absorbance and the MS/MS fragmentation patterns of these compounds.

  7. Polymorphisms of clip domain serine proteinase and serine proteinase homolog in the swimming crab Portunus trituberculatus and their association with Vibrio alginolyticus

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    Liu, Meng; Liu, Yuan; Hui, Min; Song, Chengwen; Cui, Zhaoxia

    2017-03-01

    Clip domain serine proteases (cSPs) and their homologs (SPHs) play an important role in various biological processes that are essential components of extracellular signaling cascades, especially in the innate immune responses of invertebrates. Here, polymorphisms of PtcSP and PtSPH from the swimming crab Portunus trituberculatus were investigated to explore their association with resistance/susceptibility to Vibrio alginolyticus. Polymorphic loci were identified using Clustal X, and characterized with SPSS 16.0 software, and then the significance of genotype and allele frequencies between resistant and susceptible stocks was determined by a χ 2 test. A total of 109 and 77 single nucleotide polymorphisms (SNPs) were identified in the genomic fragments of PtcSP and PtSPH, respectively. Notably, nearly half of PtSPH polymorphisms were found in the non-coding exon 1. Fourteen SNPs investigated were significantly associated with susceptibility/resistance to V. alginolyticus ( P <0.05). Among them, eight SNPs were observed in introns, and one synonymous, four non-synonymous SNPs and one ins-del were found in coding exons. In addition, five simple sequence repeats (SSRs) were detected in intron 3 of PtcSP. Although there was no statistically significant difference of allele frequencies, the SSRs showed different polymorphic alleles on the basis of the repeat number between resistant and susceptible stocks. After further validation, polymorphisms investigated here might be applied to select potential molecular markers of P. trituberculatus with resistance to V. alginolyticus.

  8. Investigation of the roles of T6SS genes in motility, biofilm formation, and extracellular protease Asp production in Vibrio alginolyticus with modified Gateway-compatible plasmids.

    Science.gov (United States)

    Liu, H; Gu, D; Sheng, L; Wang, Q; Zhang, Y

    2012-07-01

    The aims of this study were to create and evaluate the Gateway-compatible plasmids for investigating the function of genes in Vibrio alginolyticus and other Gram-negative bacteria. In this study, Gateway-compatible plasmids were successfully constructed for rapid and comprehensive function analysis of genes. Taking advantage of these plasmids, the in-frame deletion mutant strains and their complemented strains of five T6SS genes, including dotU1, VEPGS_0008, VEPGS_0011, hcp2 and ppkA2, were obtained. The results illustrated that all the mutant strains showed no significant effects on extracellular protease production, expression of Hcp1, and biofilm formation when compared to the wild-type strain, but in-frame deletion of VEPGS_0008 resulted in obvious biofilm reduction and the complemented strain restored to the level of the wild-type strain. Besides, in-frame deletion of dotU1, VEPGS_0008 and ppkA2 abolished the swarming ability. A set of Gateway-compatible vectors for internal insertion, in-frame deletion and complementation of the target genes is constructed to facilitate the general and rapid function analysis of genes involved in T6SS in Vibrio alginolyticus. The modified Gateway-compatible plasmids greatly facilitate the high-throughput and convenient function analysis of the unidentified genes. No claim to Chinese Government works. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  9. Isolation of bioactive compound from marine seaweeds against fish pathogenic bacteria Vibrio alginolyticus (VA09 and characterisation by FTIR

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    Rajasekar Thirunavukkarasu

    2013-08-01

    Full Text Available Objective: Fresh marine seaweeds Gracilaria edulis, Gracillaria verrcosa, Acanthospora spicifera, Ulva facita, Ulva lacta (U. lacta, Kappaphycus spicifera, Sargassum ilicifolium, Sargassum wightii (S. wightii, Padina tetramatica and Padina gymonospora were collected from Mandapam (Rameshwaram, Tamil Nadu of South East coast of India and were screened for antibacterial activity. Methods: All the collected seaweeds were extracted by using five different solvent (methanol, isopropanol, acetone, chloroform, diethyl ether to study their extracts against fish pathogenic bacteria V. alginolyticus (VA09 purchased from MTCC. And minimum inhibition carried out by using Resazurin micro-titre assay. Crude extract of S. wightii analysied by FTIR. Results: The methanolic extract of S. wightii produced a maximum zone of inhibition (1.95±0.11 cm, isopropanol extract maximum inhibition was produced by S. wightii (1.93±0.78 cm, Acetone extract of Gracilaria verrcosa showed maximum zone of inhibition (1.36±0.05 cm, chloroform extract of S. wightii produced a maximum zone (1.56±0.25 cm and diethyl ether extract of S. wightii produced maximum zone of inhibition(1.86±0.11 cm. Based on the antibacterial activity S. wightii, U. lacta and Padina tetramatica showed best antibacterial activity against Vibrio harveyi. In this three seaweeds were taken for MIC study. The S. wightii methanolic extract, U. lacta diethyl ether extract and Padina tetramatica methanolic extract showed a higher MIC values, and despectively were 25 mg/mL, 50 mg/mL and 50 mg/mL. FTIR result showed that mostly phenolic compounds were present in the S. wightii. Conclusions: Based on the FTIR result S. wightii have high amount of phenolic compound. Phenolic compound have the good antimicrobial activity. The results clearly show that seaweed S. wightii is an interesting source for biologically active compounds that may be applied for prophylaxis and therapy of bacterial fish diseases and it should

  10. A New Membrane Lipid Raft Gene SpFLT-1 Facilitating the Endocytosis of Vibrio alginolyticus in the Crab Scylla paramamosain.

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    Fangyi Chen

    Full Text Available Pathogens can enter their host cells by way of endocytosis in which the membrane lipid raft gene flotillins are probably involved in the invasion process and this is an important way to cause infection. In this study, a new gene SpFLT-1 was identified in Scylla paramamosain, which shared high identity with the flotillin-1 of other species. The SpFLT-1 gene was widely distributed in tissues and showed the highest level of mRNA transcripts in the hemocytes. This gene might be a maternal gene based on the evident results that it was highly expressed in maternal ovaries and in the early developmental stages of the zygote and early embryo stage whereas it gradually decreased in zoea 1. SpFLT-1 positively responded to the challenge of Vibrio alginolyticus with a significantly increased level of mRNA expression in the hemocytes and gills at 3 hours post infection (hpi. The SpFLT-1 protein was detected densely in the same fraction layer where the Vibrio protein was most present in the hemocytes and gills at 3 hpi. Furthermore, it was found that the expression of SpFLT-1 decreased to the base level following disappearance of the Vibrio protein at 6 hpi in the gills. Silencing SpFLT-1 inhibited the endocytosis rate of V. alginolyticus but overexpression of the gene could facilitate bacterial entry into the epithelioma papulosum cyprinid cells. Our study indicated that SpFLT-1 may act as a key protein involved in the process of bacterial infection and this sheds light on clarifying the pathogenesis of pathogens infecting S. paramamosain.

  11. The crustin-like peptide plays opposite role in shrimp immune response to Vibrio alginolyticus and white spot syndrome virus (WSSV) infection.

    Science.gov (United States)

    Sun, Baozhen; Wang, Zhi; Zhu, Fei

    2017-07-01

    Crustin is an antimicrobial peptide (AMP) that plays a key role in innate immunity of crustaceans. In this study, we cloned the entire 660 bp crustin-like sequence with a 507 bp open reading frame encoding a 168 amino acid from Marsupenaeus japonicus. The crustin-like gene was primarily expressed in gills and over-expressed in shrimp hemocytes after challenge with WSSV or Vibrio alginolyticus. After knockdown crustin-like gene using specific double-stranded RNA (CRU-dsRNA), IMD, Rab7, L-lectin, mitogen-activated protein kinase, p53, prophenoloxidase and Rho were down-regulated and nitric oxide synthase, myosin and tumor necrosis factor-α were up-regulated in hemocytes at 24 h post dsRNA treatment. After WSSV challenge, The mortality, WSSV copy number and expressions of WSSV immediate early genes (IE1, IE2, DNA polymerase, VP28) were both decreased but the apoptosis rate was increased in CRU-dsRNA-treated shrimps, indicating that WSSV may take advantage of crustin-like to benefit its replication. After silenced the crustin-like, the results of phagocytosis showed that the phagocytic rate of shrimp hemocytes on WSSV decreased significantly. In contrast, the absence of crustin-like in shrimps increased the mortality following V. alginolyticus challenge, indicating that crustin-like may play a positive role in the antibacterial process. The phagocytosis experiment showed there was a higher phagocytosis rate of hemocytes after CRU-dsRNA treatment. The result indicated that V. alginolyticus may be able to use crustin-like to avoid phagocytosis of shrimp hemocytes. These results further added to our understanding of the function of crustin-like peptide and also provided its potential role in innate immunity in shrimp. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Activation of immunity, immune response, antioxidant ability, and resistance against Vibrio alginolyticus in white shrimp Litopenaeus vannamei decrease under long-term culture at low pH.

    Science.gov (United States)

    Chen, Yu-Yuan; Chen, Jiann-Chu; Tseng, Kuei-Chi; Lin, Yong-Chin; Huang, Chien-Lun

    2015-10-01

    The growth, activation of immunity, immune parameters, and transcript levels of cytMnSOD, mtMnSOD, ecCuZnSOD, glutathione peroxidase (GPx), catalase, lysozyme, and penaeidin 3a were examined in white shrimp Litopenaeus vannamei reared at pH 6.8 and 8.1 after 24 weeks. No significant difference in growth was observed between the two groups. An in vitro study indicated that phenoloxidase activity and respiratory bursts (RB, release of the superoxide anion) were significantly higher in the haemocytes of pH 8.1 shrimp (shrimp reared at pH 8.1) than in pH 6.8 shrimp (shrimp reared at pH 6.8). An in vivo study indicated that the levels of immune parameters of pH 8.1 shrimp were significantly higher than in pH 6.8 shrimp, and the transcript levels of cytMnSOD, ecCuZnSOD, glutathione peroxidase, lysozyme, and penaeidin 3a were down-regulated in pH 6.8 shrimp. In another experiment, shrimp reared at pH 6.8 and 8.1 for 24 weeks were challenged with Vibrio alginolyticus. The mortality rate of pH 6.8 shrimp was significantly higher than in pH 8.1 shrimp over 12-168 h. Phagocytic activity, phagocytic index, and clearance efficiency to V. alginolyticus were significantly lower in pH 6.8 shrimp. We concluded that shrimp under long-term culture at pH 6.8 exhibited decreased resistance against V. alginolyticus as evidenced by reductions in the activation of immunity and immune parameters together with decreased transcript levels of cytMnSOD, ecCuZnSOD, GPx, lysozyme, and penaeidin 3a. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A Rac1 GTPase is a critical factor in the immune response of shrimp (Litopenaeus vannamei) to Vibrio alginolyticus infection.

    Science.gov (United States)

    Cha, Gui-Hong; Wang, Wei-Na; Peng, Ting; Huang, Ming-Zhu; Liu, Yuan

    2015-08-01

    The small GTPase Rac1 acts as a molecular switch for signal transduction that regulates various cellular functions. However, its functions in crustaceans remain unclear. In this study, a cDNA encoding a RAS GTPase (LvRac1) in the Pacific white shrimp (L. vannamei) was identified and characterized. A recombinant variant of this GTPase, rLvRac1, was expressed in the model organism P. pastoris and its expression was confirmed by mass spectrometry. Biochemical assays indicated that the recombinant protein retained GTPase activity and was expressed in all of the organism's tested tissues. Injection of the bacterium V. alginolyticus into L. vannamei induced hepatopancreatic upregulation of LvRac1 expression. Moreover, knocking down LvRac1 in vivo significantly reduced the expression of the L. vannamei p53 and Cu/Zn superoxide dismutase genes (Lvp53 and LvCu/Zn SOD, respectively) while increasing that of the galectin gene (Lvgal). Hemolymph samples from control and LvRac1-silenced L. vannamei individuals were analyzed by flow cytometry, revealing that the latter exhibited significantly reduced respiratory burst activity and total hemocyte counts. Cumulative mortality in shrimp lacking LvRac1 was significantly greater than in control groups following V. alginolyticus challenge. The silencing of LvRac1 by double-stranded RNA injection thus increased the V. alginolyticus challenge sensitivity of L. vannamei and weakened its bacterial clearance ability in vivo. Suppressing LvRac1 also promoted the upregulation of Lvp53, LvCu/ZnSOD, and Lvgal following V. alginolyticus injection. Taken together, these results suggest that LvRac1 is important in the innate immune response of shrimp to V. alginolyticus infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Comparative study on the antibiotic susceptibility and plasmid profiles of Vibrio alginolyticus strains isolated from four Tunisian marine biotopes.

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    Lajnef, Rim; Snoussi, Mejdi; Romalde, Jesús López; Nozha, Cohen; Hassen, Abdennaceur

    2012-12-01

    The antibiotic resistance patterns and the plasmids profiles of the predominant etiological agent responsible for vibriosis in Tunisia, V. alginolyticus were studied to contribute to control their spread in some Mediterranean aquaculture farms and seawater. The sixty-nine V. alginolyticus strains isolated from different marine Tunisian biotopes (bathing waters, aquaculture and conchylicole farms and a river connected to the seawater during the cold seasons) were multi-drug resistant with high resistance rate to ampicillin, kanamycin, doxycyclin, erythromycin, imipinem, and nalidixic acid. The multiple resistance index ranged from 0.3 to 0.7 for the isolates of Khenis, from 0.5 to 0.8 for those of Menzel Jmil, from 0.5 to 0.75 (Hergla) and from 0.3 to 0.7 for the isolates of Oued Soltane. The high value of antibiotic resistance index was recorded for the V. alginolyticus population isolated from the fish farm in Hergla (ARI = 0.672) followed by the population isolated from the conchylicole station of Menzel Jmil (ARI = 0.645). The results obtained by the MIC tests confirmed the resistance of the V. alginolyticus to ampicillin, erythromycin, kanamycin, cefotaxime, streptomycin and trimethoprim. Plasmids were found in 79.48 % of the strains analyzed and 30 different plasmid profiles were observed. The strains had a high difference in the size of plasmids varying between 0.5 and 45 kb. Our study reveals that the antibiotic-resistant bacteria are widespread in the aquaculture and conchylicole farm relatively to others strains isolated from seawater.

  15. Antifouling Activity towards Mussel by Small-Molecule Compounds from a Strain of Vibrio alginolyticus Bacterium Associated with Sea Anemone Haliplanella sp.

    Science.gov (United States)

    Wang, Xiang; Huang, Yanqiu; Sheng, Yanqing; Su, Pei; Qiu, Yan; Ke, Caihuan; Feng, Danqing

    2017-03-28

    Mussels are major fouling organisms causing serious technical and economic problems. In this study, antifouling activity towards mussel was found in three compounds isolated from a marine bacterium associated with the sea anemone Haliplanella sp. This bacterial strain, called PE2, was identified as Vibrio alginolyticus using morphology, biochemical tests, and phylogenetic analysis based on sequences of 16S rRNA and four housekeeping genes (rpoD, gyrB, rctB, and toxR). Three small-molecule compounds (indole, 3-formylindole, and cyclo (Pro-Leu)) were purified from the ethyl acetate extract of V. alginolyticus PE2 using column chromatography techniques. They all significantly inhibited byssal thread production of the green mussel Perna viridis, with EC50 values of 24.45 μg/ml for indole, 50.07 μg/ml for 3-formylindole, and 49.24 μg/ml for cyclo (Pro-Leu). Previous research on the antifouling activity of metabolites from marine bacteria towards mussels is scarce. Indole, 3-formylindole and cyclo (Pro-Leu) also exhibited antifouling activity against settlement of the barnacle Balanus albicostatus (EC50 values of 8.84, 0.43, and 11.35 μg/ml, respectively) and the marine bacterium Pseudomonas sp. (EC50 values of 42.68, 69.68, and 39.05 μg/ml, respectively). These results suggested that the three compounds are potentially useful for environmentally friendly mussel control and/or the development of new antifouling additives that are effective against several biofoulers.

  16. Comparative assessment of Vibrio virulence in marine fish larvae

    DEFF Research Database (Denmark)

    Rønneseth, A.; Castillo, D.; D'Alvise, Paul

    2017-01-01

    Vibrionaceae infections are a major obstacle for marine larviculture; however, little is known about virulence differences of Vibrio strains. The virulence of Vibrio strains, mostly isolated from vibriosis outbreaks in farmed fish, was tested in larval challenge trials with cod (Gadus morhua...... effects on survival. Some Vibrio strains were pathogenic in all of the larva species, while some caused disease only in one of the species. Twenty-nine of the Vibrio anguillarum strains increased the mortality of larvae from at least one fish species; however, pathogenicity of the strains differed...... markedly. Other Vibrio species had no or less pronounced effects on larval mortalities. Iron uptake has been related to V. anguillarum virulence; however, the presence or absence of the plasmid pJM1 encoding anguibactin did not correlate with virulence. The genomes of V. anguillarum were compared (D...

  17. Litopenaeus vannamei tumor necrosis factor receptor-associated factor 6 (TRAF6) responds to Vibrio alginolyticus and white spot syndrome virus (WSSV) infection and activates antimicrobial peptide genes.

    Science.gov (United States)

    Wang, Pei-Hui; Wan, Ding-Hui; Gu, Zhi-Hua; Deng, Xie-Xiong; Weng, Shao-Ping; Yu, Xiao-Qiang; He, Jian-Guo

    2011-01-01

    Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is a key signaling adaptor protein not only for the TNFR superfamily but also for the Interleukin-1 receptor/Toll-like receptor (IL-1/TLR) superfamily. To investigate TRAF6 function in invertebrate innate immune responses, Litopenaeus vannamei TRAF6 (LvTRAF6) was identified and characterized. The full-length cDNA of LvTRAF6 is 2823bp long, with an open reading frame (ORF) encoding a putative protein of 594 amino acids, including a RING-type Zinc finger, two TRAF-type Zinc fingers, a coiled-coil region, and a meprin and TRAF homology (MATH) domain. The overall amino acid sequence identity between LvTRAF6 and other known TRAF6s is 22.2-33.3%. Dual luciferase reporter assays in Drosophila S2 cells revealed that LvTRAF6 could activate the promoters of antimicrobial peptide genes (AMPs), including Drosophila Attacin A and Drosomycin, and shrimp Penaeidins. Real-time quantitative PCR (qPCR) indicated that LvTRAF6 was constitutively expressed in various tissues of L. vannamei. After Vibrio alginolyticus and white spot syndrome virus (WSSV) challenge, LvTRAF6 was down-regulated, though with different expression patterns in the intestine compared to other tissues. After WSSV challenge, LvTRAF6 was up-regulated 2.7- and 2.3-fold over the control at 3h in gills and hepatopancreas, respectively. These results indicated that LvTRAF6 may play a crucial role in antibacterial and antiviral responses via regulation of AMP gene expression. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Comparative genomic analysis of Vibrio parahaemolyticus: serotype conversion and virulence

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    Gil Ana I

    2011-06-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a common cause of foodborne disease. Beginning in 1996, a more virulent strain having serotype O3:K6 caused major outbreaks in India and other parts of the world, resulting in the emergence of a pandemic. Other serovariants of this strain emerged during its dissemination and together with the original O3:K6 were termed strains of the pandemic clone. Two genomes, one of this virulent strain and one pre-pandemic strain have been sequenced. We sequenced four additional genomes of V. parahaemolyticus in this study that were isolated from different geographical regions and time points. Comparative genomic analyses of six strains of V. parahaemolyticus isolated from Asia and Peru were performed in order to advance knowledge concerning the evolution of V. parahaemolyticus; specifically, the genetic changes contributing to serotype conversion and virulence. Two pre-pandemic strains and three pandemic strains, isolated from different geographical regions, were serotype O3:K6 and either toxin profiles (tdh+, trh- or (tdh-, trh+. The sixth pandemic strain sequenced in this study was serotype O4:K68. Results Genomic analyses revealed that the trh+ and tdh+ strains had different types of pathogenicity islands and mobile elements as well as major structural differences between the tdh pathogenicity islands of the pre-pandemic and pandemic strains. In addition, the results of single nucleotide polymorphism (SNP analysis showed that 94% of the SNPs between O3:K6 and O4:K68 pandemic isolates were within a 141 kb region surrounding the O- and K-antigen-encoding gene clusters. The "core" genes of V. parahaemolyticus were also compared to those of V. cholerae and V. vulnificus, in order to delineate differences between these three pathogenic species. Approximately one-half (49-59% of each species' core genes were conserved in all three species, and 14-24% of the core genes were species-specific and in different

  19. Prevalence study of Vibrio species and frequency of the virulence genes of Vibrio parahaemolyticus isolated from fresh and salted shrimps in Genaveh seaport

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    S Hosseini

    2014-08-01

    Full Text Available Vibrio species are important seafood-borne pathogens that are responsible for 50-70% of gasteroenteritis. The present study was carried out in order to determine the prevalence of Vibrio species and the distribution of tdh, tlh and trh virulence genes in Vibrio parahaemolyticus isolated from fresh and salted shrimp samples. Totally, 60 fresh and salted shrimp samples were collected from the Genaveh seaport. Microbial culture was used to isolate Vibrio species. In addition, the presences of Vibrio parahaemolyticus, Vibrio cholera, Vibrio vulnificus and Vibrio harveyi and the virulence genes of V. parahaemolyticus were studied using the PCR method. Results showed that 20% of fresh and 23.33% of salted shrimp samples were positive for Vibrio species. In studied samples, V. vulnificus had the highest prevalence rate (8.33%, while V. cholera had the lowest prevalence rate (1.66%. From a total of 4 detected V. parahaemolyticus, all of them had tlh gene (100%. The distribution of tdh and trh genes in isolated V. parahaemolyticus strains were 50% and 25%, respectively. High prevalence of Vibrio species and especially virulent V. parahaemolyticus in samples confirmed the lack of hygienic condition in the production and distribution centers of shrimp.

  20. Bacteriophage interactions with marine pathogenic Vibrios

    DEFF Research Database (Denmark)

    Kalatzis, Panagiotis

    Incidents of Vibrio-associated diseases in marine aquaculture are increasingly reported on a global scale, incited also by the world’s rising temperature. Administration of antibiotics has been the most commonly applied remedy used for facing vibriosis outbreaks, giving rise to concerns about...... pathogens. The combinatory administration of virulent bacteriophages φSt2 and φGrn1, isolated against Vibrio alginolyticus significantly reduced the Vibrio load in cultures of Artemia salina live prey, decreasing subsequently the risk of a vibriosis outbreak in the marine hatchery. During infection...... to studying the interactions between marine pathogenic Vibrio and their corresponding bacteriophages, while discussing the potential and limitations of phage therapy application in the biological control of vibriosis....

  1. DETECTION OF VIRULENCE GENES IN ENVIRONMENTAL STRAINS OF Vibrio cholerae FROM ESTUARIES IN NORTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    Francisca Gleire Rodrigues de Menezes

    2014-09-01

    Full Text Available The objectives of this study were to detect the presence of Vibrio cholerae in tropical estuaries (Northeastern Brazil and to search for virulence factors in the environmental isolates. Water and sediment samples were inoculated onto a vibrio-selective medium (TCBS, and colonies with morphological resemblance to V. cholerae were isolated. The cultures were identified phenotypically using a dichotomous key based on biochemical characteristics. The total DNA extracted was amplified by PCR to detect ompW and by multiplex PCR to detect the virulence genes ctx, tcp, zot and rfbO1. The results of the phenotypic and genotypic identification were compared. Nine strains of V. cholerae were identified phenotypically, five of which were confirmed by detection of the species-specific gene ompW. The dichotomous key was efficient at differentiating environmental strains of V. cholerae. Strains of V. cholerae were found in all four estuaries, but none possessed virulence genes.

  2. Detection of virulence genes in environmental strains of Vibrio cholerae from estuaries in northeastern Brazil.

    Science.gov (United States)

    Menezes, Francisca Gleire Rodrigues de; Neves, Soraya da Silva; Sousa, Oscarina Viana de; Vila-Nova, Candida Machado Vieira Maia; Maggioni, Rodrigo; Theophilo, Grace Nazareth Diogo; Hofer, Ernesto; Vieira, Regine Helena Silva dos Fernandes

    2014-01-01

    The objectives of this study were to detect the presence of Vibrio cholerae in tropical estuaries (Northeastern Brazil) and to search for virulence factors in the environmental isolates. Water and sediment samples were inoculated onto a vibrio-selective medium (TCBS), and colonies with morphological resemblance to V. cholerae were isolated. The cultures were identified phenotypically using a dichotomous key based on biochemical characteristics. The total DNA extracted was amplified by PCR to detect ompW and by multiplex PCR to detect the virulence genes ctx, tcp, zot and rfbO1. The results of the phenotypic and genotypic identification were compared. Nine strains of V. cholerae were identified phenotypically, five of which were confirmed by detection of the species-specific gene ompW. The dichotomous key was efficient at differentiating environmental strains of V. cholerae. Strains of V. cholerae were found in all four estuaries, but none possessed virulence genes.

  3. DETECTION OF VIRULENCE GENES IN ENVIRONMENTAL STRAINS OF Vibrio cholerae FROM ESTUARIES IN NORTHEASTERN BRAZIL

    Science.gov (United States)

    de Menezes, Francisca Gleire Rodrigues; Neves, Soraya da Silva; de Sousa, Oscarina Viana; Vila-Nova, Candida Machado Vieira Maia; Maggioni, Rodrigo; Theophilo, Grace Nazareth Diogo; Hofer, Ernesto; Vieira, Regine Helena Silva dos Fernandes

    2014-01-01

    The objectives of this study were to detect the presence of Vibrio cholerae in tropical estuaries (Northeastern Brazil) and to search for virulence factors in the environmental isolates. Water and sediment samples were inoculated onto a vibrio-selective medium (TCBS), and colonies with morphological resemblance to V. cholerae were isolated. The cultures were identified phenotypically using a dichotomous key based on biochemical characteristics. The total DNA extracted was amplified by PCR to detect ompW and by multiplex PCR to detect the virulence genes ctx, tcp, zot and rfbO1. The results of the phenotypic and genotypic identification were compared. Nine strains of V. cholerae were identified phenotypically, five of which were confirmed by detection of the species-specific gene ompW. The dichotomous key was efficient at differentiating environmental strains of V. cholerae. Strains of V. cholerae were found in all four estuaries, but none possessed virulence genes. PMID:25229224

  4. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for polymerase chain ...

  5. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    DRINIE

    2003-04-02

    Apr 2, 2003 ... A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for ...

  6. Tropical Atlantic marine macroalgae with bioactivity against virulent and antibiotic resistant Vibrio

    Directory of Open Access Journals (Sweden)

    Giselle Cristina Silva

    2013-03-01

    Full Text Available The antibacterial activity of ethanol, methanol, hexane and acetone-based extracts of the macroalgae Padina gymnospora (PG, Hypnea musciformes (HM, Ulva fasciata (UF and Caulerpa prolifera (CP was investigated. The disk diffusion method was used to evaluate the algae antimicrobial effect against standard strains of Vibrio parahaemolyticus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enterica and five virulent antibiotic-resistant strains of V. brasiliensis, V. xuii and V. navarrensis (isolated from the hemolymph of Litopenaeus vannamei. Ethanol extracts of PG and HM inhibited all Vibrio strains. E. coli and P. aeruginosa were only susceptible to ethanol extracts of PG. Among the methanol extracts, only UF was bioactive, inhibiting V. navarrensis. The observed inhibitory effect of ethanol extracts of PG, HM and UF against virulent antibiotic-resistant bacteria suggests these macroalgal species constitute a potential source of bioactive compounds.

  7. Nigribactin, a Novel Siderophore from Vibrio nigripulchritudo, Modulates Staphylococcus aureus Virulence Gene Expression

    Directory of Open Access Journals (Sweden)

    Lone Gram

    2012-11-01

    Full Text Available Staphylococcus aureus is a serious human pathogen that employs a number of virulence factors as part of its pathogenesis. The purpose of the present study was to explore marine bacteria as a source of compounds that modulate virulence gene expression in S. aureus. During the global marine Galathea 3 expedition, a strain collection was established comprising bacteria that express antimicrobial activity against Vibrio anguillarum and/or Staphylococcus aureus. Within this collection we searched colony material, culture supernatants, and cell extracts for virulence modulating activity showing that 68 out of 83 marine bacteria (affiliated with the Vibrionaceae and Pseudoalteromonas sp. influenced expression of S. aureus hla encoding α-hemolysin toxin and/or spa encoding Protein A. The isolate that upon initial screening showed the highest degree of interference (crude ethyl acetate extract was a Vibrio nigripulchritudo. Extraction, purification and structural elucidation revealed a novel siderophore, designated nigribactin, which induces spa transcription. The effect of nigribactin on spa expression is likely to be independent from its siderophore activity, as another potent siderophore, enterobactin, failed to influence S. aureus virulence gene expression. This study shows that marine microorganisms produce compounds with potential use in therapeutic strategies targeting virulence rather than viability of human pathogens.

  8. [Prophage CTXphi genome variability and its role in alteration of Vibrio cholerae El Tor virulence characteristics].

    Science.gov (United States)

    Smirnova, N I; Osin, A V; Nefedov, K S; Kul'shan', T A; Zadnova, S P; Livanova, L F; Toporkov, A V; Kutyrev, V V

    2007-01-01

    Comparative analysis of CTXphi prophage genome of 366 V. cholerae El Tor strains isolated from infected people and water was carried out using the polymerase chain reaction. Four groups of vibrios, which carry different combinations of ctxA, zot, and ace genes from core region of CTXphi prophage coding key (cholera enterotoxin) and accessory (Zot and Ace toxins) pathogenicity factors, were determined: ctxA(+) zot(-) ace(+), ctxA(-) zot(+) ace(+), ctxA(-) zot(+) ace(-), ctxA(-) zot(-) ace(+). Vibrios that had lost all tested genes were also revealed. Genomic rearrangements occurring in water environment in virulent V. cholerae strains, which acquired foreign pathogenicity genes necessary for their existence in human organism, were proposed as one of the mechanisms of formation of clones with an incomplete or no prophage. Infection process in model animals challenged with wild and isogenic strains of V. cholerae differing in the set of the phage genes (ctxA, zot, and ace) was comparatively analyzed. It was shown that variability of CTXphi prophage genome was an important factor of modification of cholera vibrios virulent characteristics. Obtained data point to usefulness of ctxA, zot, and ace phage genes detection in wild V. cholerae isolates as it could permit evaluation of their virulent potential determining the severity of the infection.

  9. Characterization of the BPI-like gene from a subtracted cDNA library of large yellow croaker (Pseudosciaena crocea) and induced expression by formalin-inactivated Vibrio alginolyticus and Nocardia seriolae vaccine challenges.

    Science.gov (United States)

    Huang, Yanqing; Lou, Huifang; Wu, Xinzhong; Chen, Yanxia

    2008-12-01

    One expressed sequence tag (EST 64LF004 clone), which is from the subtracted cDNA library of the head kidney of large yellow croaker (Pseudosciaena crocea) stimulated with peptidoglycan (PG) by suppression subtractive hybridization (SSH) method, was cloned using RACE-PCR. The full length cDNA, which possesses typical structural features of a signal peptide, a conserved LPS binding domain and two bactericidal permeability-increasing (BPI) motifs as in higher vertebrates, was identified as a novel homologue, namely of the large yellow croaker BPI-like molecule (Pc-BPI-L). Phylogenetic analysis showed this Pc-BPI-L of large yellow croaker as the most ancestral branch in bony fish clade. The recombinant Pc-BPI-L protein expressed in the Tn-5B1-4 insect cells was successfully produced and confirmed to have the predicted size of 52 kDa by Western blot analysis. At the message level, Pc-BPI-L mRNA was ubiquitously expressed in all tissues examined. Following formalin-inactivated Vibrio alginolyticus and Nocardia seriolae treatment, Pc-BPI-L message was differentially up-regulated in primary immune organs. These results indicate that Pc-BPI-L might be involved in the immune response to bacterial infection.

  10. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    . cholerae and the invasion plasmid antigen gene (ipaH) of virulent Shigella spp., was performed and the PCR products were visualised by agarose gel electrophoresis. The assay allowed the detection of as few as 1 cfu/100 ml of V. cholerae ...

  11. Nigribactin, a Novel Siderophore from Vibrio nigripulchritudo, Modulates Staphylococcus aureus Virulence Gene Expression

    DEFF Research Database (Denmark)

    Nielsen, Anita; Månsson, Maria; Wietz, Matthias

    2012-01-01

    Staphylococcus aureus is a serious human pathogen that employs a number of virulence factors as part of its pathogenesis. The purpose of the present study was to explore marine bacteria as a source of compounds that modulate virulence gene expression in S. aureus. During the global marine Galathea...... 3 expedition, a strain collection was established comprising bacteria that express antimicrobial activity against Vibrio anguillarum and/or Staphylococcus aureus. Within this collection we searched colony material, culture supernatants, and cell extracts for virulence modulating activity showing...... that 68 out of 83 marine bacteria (affiliated with the Vibrionaceae and Pseudoalteromonas sp.) influenced expression of S. aureus hla encoding α-hemolysin toxin and/or spa encoding Protein A. The isolate that upon initial screening showed the highest degree of interference (crude ethyl acetate extract...

  12. Bicarbonate Increases Binding Affinity of Vibrio cholerae ToxT to Virulence Gene Promoters

    Science.gov (United States)

    Thomson, Joshua J.

    2014-01-01

    The major Vibrio cholerae virulence gene transcription activator, ToxT, is responsible for the production of the diarrhea-inducing cholera toxin (CT) and the major colonization factor, toxin coregulated pilus (TCP). In addition to the two primary virulence factors mentioned, ToxT is responsible for the activation of accessory virulence genes, such as aldA, tagA, acfA, acfD, tcpI, and tarAB. ToxT activity is negatively modulated by bile and unsaturated fatty acids found in the upper small intestine. Conversely, previous work identified another intestinal signal, bicarbonate, which enhances the ability of ToxT to activate production of CT and TCP. The work presented here further elucidates the mechanism for the enhancement of ToxT activity by bicarbonate. Bicarbonate was found to increase the activation of ToxT-dependent accessory virulence promoters in addition to those that produce CT and TCP. Bicarbonate is taken up into the V. cholerae cell, where it positively affects ToxT activity by increasing DNA binding affinity for the virulence gene promoters that ToxT activates regardless of toxbox configuration. The increase in ToxT binding affinity in the presence of bicarbonate explains the elevated level of virulence gene transcription. PMID:25182489

  13. Genome sequencing and analysis of a highly virulent Vibrio parahaemolyticus strain isolated from the marine environment

    Science.gov (United States)

    Parks, M. C.; Moreno, E.

    2016-02-01

    Vibrio parahaemolyticus [Vp] is a Gram-negative bacterium and a natural inhabitant of coastal marine ecosystems worldwide. Vp is also a coincidental pathogen of humans. Virulent strains are commonly identified by the presence of the thermostable direct (tdh) or tdh-related (trh) hemolysin genes. However, virulence is multifaceted and many clinical Vp isolates do not carry tdh or trh. In this study, we sequenced and assembled the draft genome of a tdh- and trh-negative environmental isolate (805) shown previously to be highly virulent in zebrafish. To investigate potential mechanisms of virulence, we compared 805 to the clinical V. parahaemolyticus type strain (RIMD2210633). Pairwise comparison revealed the presence of multiple genomic regions including an IncF conjugative pilus (1.3 Kb) and a colicin V plasmid (1.49 Kb). These features are homologous to genomic regions present in clinical V. vulnificus and V. cholerae strains. Genome comparison also revealed the presence of five toxin-antitoxin systems. Isolate 805 likely attained these new features through the lateral acquisition of mobile genomic material - a hypothesis supported by the aberrant GC content of these regions. Colicin V plasmids are a diverse group of IncF plasmids found in invasive bacterial strains. Similarly, an abundance of toxin-antitoxin systems have been linked to virulence in Gram-negative bacteria. Current efforts are focused on characterizing 142 coding features present in 805 but absent from the type strain.

  14. Variable Virulence of Biotype 3 Vibrio vulnificus due to MARTX Toxin Effector Domain Composition.

    Science.gov (United States)

    Kim, Byoung Sik; Gavin, Hannah E; Satchell, Karla J F

    2017-01-01

    Vibrio vulnificus is an environmental organism that causes septic human infections characterized by high morbidity and mortality. The annual incidence and global distribution of this pathogen are increasing as ocean waters warm. Clinical strains exhibit variations in the primary virulence toxin, suggesting a potential for the emergence of new strains with altered virulence properties. A clonal outbreak of tilapia-associated wound infections in Israel serves as a natural experiment for the sudden emergence of a new V. vulnificus strain. The effector domain content of the multifunctional autoprocessing RTX (MARTX) toxin of the outbreak-associated biotype 3 (BT3) strains was previously shown to harbor a modification generated by recombination. The modification introduced an actin-induced adenylate cyclase effector domain (ExoY) and an effector domain that disrupts the Golgi organelle (DmX). Here, we report that the exchange of these effector domains for a putative progenitor biotype 1 toxin arrangement produces a toxin that slows the lysis kinetics of targeted epithelial cells but increases cellular rounding phenotypes in response to bacteria. In addition, replacing the biotype 3 toxin variant with the putative progenitor biotype 1 variant renders the resulting strain significantly more virulent in mice. This suggests that the exchange of MARTX effector domains during the emergence of BT3 generated a toxin with reduced toxin potency, resulting in decreased virulence of this outbreak-associated strain. We posit that selection for reduced virulence may serve as a route for this lethal infectious agent to enter the human food chain by allowing it to persist in natural hosts. IMPORTANCEVibrio vulnificus is a serious infection linked to climate change. The virulence capacity of these bacteria can vary by gene exchange, resulting in new variants of the primary virulence toxin. In this study, we tested whether the emergence of an epidemic strain of V. vulnificus with a

  15. Role of Indole Production on Virulence of Vibrio cholerae Using Galleria mellonella Larvae Model.

    Science.gov (United States)

    Nuidate, Taiyeebah; Tansila, Natta; Saengkerdsub, Suwat; Kongreung, Jetnaphang; Bakkiyaraj, Dhamodharan; Vuddhakul, Varaporn

    2016-09-01

    Cell to cell communication facilitated by chemical signals plays crucial roles in regulating various cellular functions in bacteria. Indole, one such signaling molecule has been demonstrated to control various bacterial phenotypes such as biofilm formation and virulence in diverse bacteria including Vibrio cholerae. The present study explores some key factors involved in indole production and the subsequent pathogenesis of V. cholerae. Indole production was higher at 37 °C than at 30 °C, although the growth at 37 °C was slightly higher. A positive correlation was observed between indole production and biofilm formation in V. cholerae. Maximum indole production was detected at pH 7. There was no significant difference in indole production between clinical and environmental V. cholerae isolates, although indole production in one environmental isolate was significantly different. Both growth and indole production showed relevant changes with differences in salinity. An indole negative mutant strain was constructed using transposon mutagenesis and the direct effect of indole on the virulence of V. cholerae was evaluated using Galleria mellonella larvae model. Comparison to the wild type strain, the mutant significantly reduced the mortality of G. mellonella larvae which regained its virulence after complementation with exogenous indole. A gene involved in indole production and the virulence of V. cholerae was identified.

  16. Virulence of an emerging pathogenic lineage of Vibrio nigripulchritudo is dependent on two plasmids.

    Science.gov (United States)

    Le Roux, Frédérique; Labreuche, Yannick; Davis, Brigid M; Iqbal, Naeem; Mangenot, Sophie; Goarant, Cyrille; Mazel, Didier; Waldor, Matthew K

    2011-02-01

    Vibrioses are the predominant bacterial infections in marine shrimp farms. Vibrio nigripulchritudo is an emerging pathogen of the cultured shrimp Litopenaeus stylirostris in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have revealed that recent pathogenic V. nigripulchritudo isolates from New Caledonia all cluster into a monophyletic clade and contain a small plasmid, pB1067. Here, we report that a large plasmid, pA1066 (247 kb), can also serve as a marker for virulent V. nigripulchritudo, and that an ancestral version of this plasmid was likely acquired prior to other virulence-linked markers. Additionally, we demonstrate that pA1066 is critical for the full virulence of V. nigripulchritudo in several newly developed experimental models of infection. Plasmid pB1067 also contributes to virulence; only strains containing both plasmids induced the highest level of shrimp mortality. Thus, it appears that these plasmids, which are absent from non-pathogenic isolates, may be driving forces, as well as markers, for the emergence of a pathogenic lineage of V. nigripulchritudo.

  17. Ecological fitness and virulence features of Vibrio parahaemolyticus in estuarine environments.

    Science.gov (United States)

    Lovell, Charles R

    2017-03-01

    Vibrio parahaemolyticus is a commonly encountered and highly successful organism in marine ecosystems. It is a fast-growing, extremely versatile copiotroph that is active over a very broad range of conditions. It frequently occurs suspended in the water column (often attached to particles or zooplankton), and is a proficient colonist of submerged surfaces. This organism is an important pathogen of animals ranging from microcrustaceans to humans and is a causative agent of seafood-associated food poisoning. This review examines specific ecological adaptations of V. parahaemolyticus, including its broad tolerances to temperature and salinity, its utilization of a wide variety of organic carbon and energy sources, and its pervasive colonization of suspended and stationary materials that contribute to its success and ubiquity in temperate and tropical estuarine ecosystems. Several virulence-related features are examined, in particular the thermostable direct hemolysin (TDH), the TDH-related hemolysin (TRH), and the type 3 secretion system, and the possible importance of these features in V. parahaemolyticus pathogenicity is explored. The impact of new and much more effective PCR primers on V. parahaemolyticus detection and our views of virulent strain abundance are also described. It is clear that strains carrying the canonical virulence genes are far more common than previously thought, which opens questions regarding the role of these genes in pathogenesis. It is also clear that virulence is an evolving feature of V. parahaemolyticus and that novel combinations of virulence factors can lead to emergent virulence in which a strain that is markedly more pathogenic evolves and propagates to produce an outbreak. The effects of global climate change on the frequency of epidemic disease, the geographic distribution of outbreaks, and the human impacts of V. parahaemolyticus are increasing and this review provides information on why this ubiquitous human pathogen has

  18. Detection of virulence associated genes, haemolysin and protease amongst Vibrio cholerae isolated in Malaysia.

    Science.gov (United States)

    Iyer, L; Vadivelu, J; Puthucheary, S D

    2000-08-01

    Eighty-four strains of Vibrio cholerae O1, O139 and non-O1/non-O139 from clinical and environmental sources were investigated for the presence of the toxin co-regulated pilus gene, tcpA, the virulence cassette genes ctxA, zot, ace and cep and also for their ability to elaborate haemolysin and protease. The ctxA and zot genes were detected using DNA-DNA hybridization while the ace, cep and tcpA genes were detected using PCR. Production of haemolysin and protease was detected using mammalian erythrocytes and an agar diffusion assay respectively. Analysis of their virulence profiles showed six different groups designated Type I to Type VI and the major distinguishing factor among these profiles was in the in vitro production of haemolysin and/or protease. Clinical O1, O139 and environmental O1 strains were similar with regard to presence of the virulence cassette genes. All environmental O1 strains with the exception of one were found to possess ctxA, zot and ace giving rise to the probability that these strains may actually be of clinical origin. One strain which had only cep but none of the toxin genes may be a true environmental isolate. The virulence cassette and colonization factor genes were absent in all non-O1/non-O139 environmental strains but production of both the haemolysin and protease was present, indicating that these may be putative virulence factors. These findings suggest that with regard to its pathogenic potential, only strains of the O1 and O139 serogroup that possess the tcpA gene which encodes the phage receptor, have the potential to acquire the CTX genetic element and become choleragenic.

  19. Broad spectrum pro-quorum-sensing molecules as inhibitors of virulence in vibrios.

    Directory of Open Access Journals (Sweden)

    Wai-Leung Ng

    Full Text Available Quorum sensing (QS is a bacterial cell-cell communication process that relies on the production and detection of extracellular signal molecules called autoinducers. QS allows bacteria to perform collective activities. Vibrio cholerae, a pathogen that causes an acute disease, uses QS to repress virulence factor production and biofilm formation. Thus, molecules that activate QS in V. cholerae have the potential to control pathogenicity in this globally important bacterium. Using a whole-cell high-throughput screen, we identified eleven molecules that activate V. cholerae QS: eight molecules are receptor agonists and three molecules are antagonists of LuxO, the central NtrC-type response regulator that controls the global V. cholerae QS cascade. The LuxO inhibitors act by an uncompetitive mechanism by binding to the pre-formed LuxO-ATP complex to inhibit ATP hydrolysis. Genetic analyses suggest that the inhibitors bind in close proximity to the Walker B motif. The inhibitors display broad-spectrum capability in activation of QS in Vibrio species that employ LuxO. To the best of our knowledge, these are the first molecules identified that inhibit the ATPase activity of a NtrC-type response regulator. Our discovery supports the idea that exploiting pro-QS molecules is a promising strategy for the development of novel anti-infectives.

  20. Broad spectrum pro-quorum-sensing molecules as inhibitors of virulence in vibrios.

    Science.gov (United States)

    Ng, Wai-Leung; Perez, Lark; Cong, Jianping; Semmelhack, Martin F; Bassler, Bonnie L

    2012-01-01

    Quorum sensing (QS) is a bacterial cell-cell communication process that relies on the production and detection of extracellular signal molecules called autoinducers. QS allows bacteria to perform collective activities. Vibrio cholerae, a pathogen that causes an acute disease, uses QS to repress virulence factor production and biofilm formation. Thus, molecules that activate QS in V. cholerae have the potential to control pathogenicity in this globally important bacterium. Using a whole-cell high-throughput screen, we identified eleven molecules that activate V. cholerae QS: eight molecules are receptor agonists and three molecules are antagonists of LuxO, the central NtrC-type response regulator that controls the global V. cholerae QS cascade. The LuxO inhibitors act by an uncompetitive mechanism by binding to the pre-formed LuxO-ATP complex to inhibit ATP hydrolysis. Genetic analyses suggest that the inhibitors bind in close proximity to the Walker B motif. The inhibitors display broad-spectrum capability in activation of QS in Vibrio species that employ LuxO. To the best of our knowledge, these are the first molecules identified that inhibit the ATPase activity of a NtrC-type response regulator. Our discovery supports the idea that exploiting pro-QS molecules is a promising strategy for the development of novel anti-infectives.

  1. The effect of γ radiation on the expression of the virulence genes of Salmonella typhimurium and Vibrio spp.

    Science.gov (United States)

    Lim, Sangyong; Jung, Jinwoo; Kim, Dongho

    2007-11-01

    The principle benefit of food irradiation is the reduction of food-borne bacteria in food products. However, the microbiological safety with respect to increased virulence of surviving pathogens after irradiation remains an important issue with regard to the effectiveness of food irradiation. In this study, the transcriptional changes of virulence genes of Salmonella and Vibrio spp. after γ radiation were investigated by real-time PCR (RT-PCR). Samonella typhimurium is dependent upon the products of a large number of genes located within Salmonella pathogenicity islands (SPI) on the chromosome. The expressions of seven genes including four SPI genes, hilD, ssrB, pipB, and sopD, were measured at 1 h after 1 kGy irradiation. Compared with non-irradiated controls, the expression of hilD encoded within SPI1 and sopD encoding SPI1-related effector proteins was reduced about 4- and 16-fold, respectively. The expressions of Vibrio toxin genes, vvhA, ctxA, and tdh, were also monitored during the course of a growth cycle after re-inoculation of irradiated Vibrio spp. (0.5 and 1.0 kGy). The expressions of Vibrio toxin genes tested did not increase compared with non-irradiated counterparts. Results from this study indicate that γ radiation is much more likely to reduce the virulence gene expression of surviving pathogens.

  2. Distribution and dynamics of epidemic and pandemic Vibrio parahaemolyticus virulence factors

    Directory of Open Access Journals (Sweden)

    Daniela eCeccarelli

    2013-12-01

    Full Text Available Vibrio parahaemolyticus, autochthonous to estuarine, marine, and coastal environments throughout the world, is the causative agent of food-borne gastroenteritis. More than 80 serotypes have been described worldwide, based on antigenic properties of the somatic (O and capsular (K antigens. Serovar O3:K6 emerged in India in 1996 and subsequently was isolated worldwide, leading to the conclusion that the first V. parahaemolyticus pandemic had taken place. Most strains of V. parahaemolyticus isolated from the environment or seafood, in contrast to clinical strains, do not produce a thermostable direct hemolysin (TDH and/or a TDH-related hemolysin (TRH. Type 3 secretion systems (T3SSs, needle-like apparatuses able to deliver bacterial effectors into host cytoplasm, were identified as triggering cytotoxicity and enterotoxicity. Type 6 secretion systems (T6SS predicted to be involved in intracellular trafficking and vesicular transport appear to play a role in V. parahaemolyticus virulence. Recent advances in V. parahaemolyticus genomics identified several pathogenicity islands (VpaIs located on either chromosome in both epidemic and pandemic strains and comprising additional colonization factors, such as restriction-modification complexes, chemotaxis proteins, classical bacterial surface virulence factors, and putative colicins. Furthermore, studies indicate strains lacking toxins and genomic regions associated with pathogenicity may also be pathogenic, suggesting other important virulence factors remain to be identified. The unique repertoire of virulence factors identified to date, their occurrence and distribution in both epidemic and pandemic strains worldwide are described, with the aim of highlighting the complexity of V. parahaemolyticus pathogenicity as well as its dynamic genome.

  3. A bistable switch and anatomical site control Vibrio cholerae virulence gene expression in the intestine.

    Directory of Open Access Journals (Sweden)

    Alex T Nielsen

    2010-09-01

    Full Text Available A fundamental, but unanswered question in host-pathogen interactions is the timing, localization and population distribution of virulence gene expression during infection. Here, microarray and in situ single cell expression methods were used to study Vibrio cholerae growth and virulence gene expression during infection of the rabbit ligated ileal loop model of cholera. Genes encoding the toxin-coregulated pilus (TCP and cholera toxin (CT were powerfully expressed early in the infectious process in bacteria adjacent to epithelial surfaces. Increased growth was found to co-localize with virulence gene expression. Significant heterogeneity in the expression of tcpA, the repeating subunit of TCP, was observed late in the infectious process. The expression of tcpA, studied in single cells in a homogeneous medium, demonstrated unimodal induction of tcpA after addition of bicarbonate, a chemical inducer of virulence gene expression. Striking bifurcation of the population occurred during entry into stationary phase: one subpopulation continued to express tcpA, whereas the expression declined in the other subpopulation. ctxA, encoding the A subunit of CT, and toxT, encoding the proximal master regulator of virulence gene expression also exhibited the bifurcation phenotype. The bifurcation phenotype was found to be reversible, epigenetic and to persist after removal of bicarbonate, features consistent with bistable switches. The bistable switch requires the positive-feedback circuit controlling ToxT expression and formation of the CRP-cAMP complex during entry into stationary phase. Key features of this bistable switch also were demonstrated in vivo, where striking heterogeneity in tcpA expression was observed in luminal fluid in later stages of the infection. When this fluid was diluted into artificial seawater, bacterial aggregates continued to express tcpA for prolonged periods of time. The bistable control of virulence gene expression points to a

  4. Comparison of classifications of aptamers against Vibrio ...

    African Journals Online (AJOL)

    As a novel method to detect the pathogen Vibrio alginolyticus, 45 aptamers were previously selected and tested. In order to better understand the properties of these aptamers, it was essential to classify these aptamers based on appropriate criteria. The primary structure of 45 aptamers against V. alginolyticus was analyzed ...

  5. Vibrio cholerae ensures function of host proteins required for virulence through consumption of luminal methionine sulfoxide.

    Science.gov (United States)

    Vanhove, Audrey S; Hang, Saiyu; Vijayakumar, Vidhya; Wong, Adam Cn; Asara, John M; Watnick, Paula I

    2017-06-01

    Vibrio cholerae is a diarrheal pathogen that induces accumulation of lipid droplets in enterocytes, leading to lethal infection of the model host Drosophila melanogaster. Through untargeted lipidomics, we provide evidence that this process is the product of a host phospholipid degradation cascade that induces lipid droplet coalescence in enterocytes. This infection-induced cascade is inhibited by mutation of the V. cholerae glycine cleavage system due to intestinal accumulation of methionine sulfoxide (MetO), and both dietary supplementation with MetO and enterocyte knock-down of host methionine sulfoxide reductase A (MsrA) yield increased resistance to infection. MsrA converts both free and protein-associated MetO to methionine. These findings support a model in which dietary MetO competitively inhibits repair of host proteins by MsrA. Bacterial virulence strategies depend on functional host proteins. We propose a novel virulence paradigm in which an intestinal pathogen ensures the repair of host proteins essential for pathogenesis through consumption of dietary MetO.

  6. Vibrio cholerae ensures function of host proteins required for virulence through consumption of luminal methionine sulfoxide.

    Directory of Open Access Journals (Sweden)

    Audrey S Vanhove

    2017-06-01

    Full Text Available Vibrio cholerae is a diarrheal pathogen that induces accumulation of lipid droplets in enterocytes, leading to lethal infection of the model host Drosophila melanogaster. Through untargeted lipidomics, we provide evidence that this process is the product of a host phospholipid degradation cascade that induces lipid droplet coalescence in enterocytes. This infection-induced cascade is inhibited by mutation of the V. cholerae glycine cleavage system due to intestinal accumulation of methionine sulfoxide (MetO, and both dietary supplementation with MetO and enterocyte knock-down of host methionine sulfoxide reductase A (MsrA yield increased resistance to infection. MsrA converts both free and protein-associated MetO to methionine. These findings support a model in which dietary MetO competitively inhibits repair of host proteins by MsrA. Bacterial virulence strategies depend on functional host proteins. We propose a novel virulence paradigm in which an intestinal pathogen ensures the repair of host proteins essential for pathogenesis through consumption of dietary MetO.

  7. [A comparative analysis of genomes of virulent and avirulent strains of Vibrio cholerae O139].

    Science.gov (United States)

    Eroshenko, G A; Osin, A V; Shchelkanova, E Iu; Smirnova, N I

    2004-01-01

    A comparative analysis of the genome of V. cholerae O139 strains isolated in Russia's territory from patients with cholera and from the environment showed essential differences in their structures. The genome of clinical strains possessed all tested genes associated with virulence (ctxAB, zot, ace, rstC, rtxA, hap, toxR and toxT) and the at-tRS site for the CTXp phage DNA integration. As for the O139 V. cholerae chromosome strains isolated from water, 70% of the studied genes (ctxAB, zot, ace, rstC, tcpA, and toxT) and the attRS sequence were not detected in them. A lack of the key virulence genes in O139-serogroup "water" vibrios, including genes of toxin-coregulated adhesion pili. (that are receptors for the CTXp phage), and of the attachment site of the above phage are indicative of that the O139 V. cholerae strains isolated from open water sources located in different Russia's regions are epidemically negligible.

  8. Norepinephrine and dopamine increase motility, biofilm formation and virulence of Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Qian eYang

    2014-11-01

    Full Text Available Vibrio harveyi is one of the major pathogens of aquatic organisms, affecting both vertebrates and invertebrates, and causes important losses in the aquaculture industry. In order to develop novel methods to control disease caused by this pathogen, we need to obtain a better understanding of pathogenicity mechanisms. Sensing of catecholamines increases both growth and production of virulence-related factors in pathogens of terrestrial animals and humans. However, at this moment, knowledge on the impact of catecholamines on the virulence of pathogens of aquatic organisms is lacking. In the present study, we report that in V. harveyi, norepinephrine and dopamine increased growth in serum-supplemented medium, siderophore production, swimming motility and expression of genes involved in flagellar motility, biofilm formation, and exopolysaccharide production. Consistent with this, pretreatment of V. harveyi with catecholamines prior to inoculation into the rearing water resulted in significantly decreased survival of gnotobiotic brine shrimp larvae, when compared to larvae challenged with untreated V. harveyi. Further, norepinephrine-induced effects could be neutralized by α-adrenergic antagonists or by the bacterial catecholamine receptor antagonist LED209, but not by β-adrenergic or dopaminergic antagonists. Dopamine-induced effects could be neutralized by dopaminergic antagonists or LED209, but not by adrenergic antagonists. Together, our results indicate that catecholamine sensing increases the success of transmission of V. harveyi and that interfering with catecholamine sensing might be an interesting strategy to control vibriosis in aquaculture. We hypothesise that upon tissue and/or hemocyte damage during infection, pathogens come into contact with elevated catecholamine levels, and that this stimulates the expression of virulence factors that are required to colonize a new host.

  9. Continuous Exposure Of Vibrio Anguillarum To Tropodithietic Acid: Genetic Changes And Influence On Virulence

    DEFF Research Database (Denmark)

    Rasmussen, Bastian Barker; D'Alvise, Paul; Grotkjær, Torben

    2015-01-01

    be promising as probiotics in fish rearing. Production of the antibacterial compound tropodithietic acid (TDA) by roseobacters is key in the antagonism of vibrios. However, the effects of continuous exposure to TDA on V. anguillarum remain unknown. The purpose of this study was to investigate how prolonged TDA...... exposure affects V. anguillarum focusing on the development of resistance towards TDA and changes in virulence.Methods: Seven lineages of V. anguillarum were exposed to increasing TDA concentrations over 300-400 generations and were subsequently genome sequenced. Virulence of the lineages is currently...... motor switch protein. However, mutations in this gene were observed in non-exposed controls as well.Conclusions: In conclusion, TDA resistance does not appear to develop, and the virulence genes of V. anguillarum are unaffected by TDA exposure, supporting the application of TDA-producing roseobacters...

  10. Prevalence and Antimicrobial Resistance of Vibrio spp. in Retail and Farm Shrimps in Ecuador.

    Science.gov (United States)

    Sperling, L; Alter, T; Huehn, S

    2015-11-01

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

  11. Antimicrobial Effects of Blueberry, Raspberry, and Strawberry Aqueous Extracts and their Effects on Virulence Gene Expression in Vibrio cholerae.

    Science.gov (United States)

    Khalifa, Hazim O; Kamimoto, Maki; Shimamoto, Toshi; Shimamoto, Tadashi

    2015-11-01

    The antimicrobial effects of aqueous extracts of blueberry, raspberry, and strawberry on 13 pathogenic bacteria were evaluated. The minimum inhibitory concentrations and minimum bactericidal concentrations of the extracts were determined before and after neutralization to pH 7.03 ± 0.15. Both Gram-positive and Gram-negative pathogenic bacteria were selectively inhibited by the non-neutralized berries. Blueberry was the best inhibitor, and Vibrio and Listeria were the most sensitive bacteria. After neutralization, blueberry affected only Vibrio and Listeria, whereas the antimicrobial activities of raspberry and strawberry were abolished. The total contents of phenolics, flavonoids, and proanthocyanidins in the extracts were measured with colorimetric methods and were highest in strawberry, followed by raspberry, and then blueberry. We also studied the effects of sub-bactericidal concentrations of the three berry extracts on virulence gene expression in Vibrio cholerae. Real-time quantitative reverse transcription-polymerase chain reaction revealed that the three berry extracts effectively repressed the transcription of the tcpA gene. Raspberry also repressed the transcription of the ctxA gene, whereas blueberry and strawberry did not. However, the three berry extracts did not affect the transcription of toxT. These results suggest that the three berry extracts exert potent antimicrobial effects and inhibit the expression of the virulence factors of V. cholerae. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Comparative Genomic Analysis of Two Vibrio toranzoniae Strains with Different Virulence Capacity Reveals Clues on Its Pathogenicity for Fish.

    Science.gov (United States)

    Lasa, Aide; Gibas, Cynthia J; Romalde, Jesús L

    2017-01-01

    Vibrio toranzoniae is a Gram-negative bacterium of the Splendidus clade within the Vibrio genus. V. toranzoniae was first isolated from healthy clams in Galicia (Spain) but recently was also identified associated to disease outbreaks of red conger eel in Chile. Experimental challenges showed that the Chilean isolates were able to produce fish mortalities but not the strains isolated from clams. The aim of the present study was to determine the differences at the genomic level between the type strain of the species (CECT 7225(T)) and the strain R17, isolated from red conger eel in Chile, which could explain their different virulent capacity. The genome-based comparison showed high homology between both strains but differences were observed in certain gene clusters that include some virulence factors. Among these, we found that iron acquisition systems and capsule synthesis genes were the main differential features between both genomes that could explain the differences in the pathogenicity of the strains. Besides, the studied genomes presented genomic islands and toxins, and the R17 strain presented CRISPR sequences that are absent on the type strain. Taken together, this analysis provided important insights into virulence factors of V. toranzoniae that will lead to a better understanding of the pathogenic process.

  13. The Vibrio cholerae RND efflux systems impact virulence factor production and adaptive responses via periplasmic sensor proteins.

    Science.gov (United States)

    Bina, X Renee; Howard, Mondraya F; Taylor-Mulneix, Dawn L; Ante, Vanessa M; Kunkle, Dillon E; Bina, James E

    2018-01-01

    Resistance-nodulation-division (RND) efflux systems are ubiquitous transporters in Gram-negative bacteria that are essential for antibiotic resistance. The RND efflux systems also contribute to diverse phenotypes independent of antimicrobial resistance, but the mechanism by which they affect most of these phenotypes is unclear. This is the case in Vibrio cholerae where the RND systems function in antimicrobial resistance and virulence factor production. Herein, we investigated the linkage between RND efflux and V. cholerae virulence. RNA sequencing revealed that the loss of RND efflux affected the activation state of periplasmic sensing systems including the virulence regulator ToxR. Activation of ToxR in an RND null mutant resulted in ToxR-dependent transcription of the LysR-family regulator leuO. Increased leuO transcription resulted in the repression of the ToxR virulence regulon and attenuated virulence factor production. Consistent with this, leuO deletion restored virulence factor production in an RND-null mutant, but not its ability to colonize infant mice; suggesting that RND efflux was epistatic to virulence factor production for colonization. The periplasmic sensing domain of ToxR was required for the induction of leuO transcription in the RND null mutant, suggesting that ToxR responded to metabolites that accumulated in the periplasm. Our results suggest that ToxR represses virulence factor production in response to metabolites that are normally effluxed from the cell by the RND transporters. We propose that impaired RND efflux results in periplasmic metabolite accumulation, which then activates periplasmic sensors including ToxR and two-component regulatory systems to initiate the expression of adaptive responses.

  14. Structure of Vibrio cholerae ToxT reveals a mechanism for fatty acid regulation of virulence genes

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Michael J.; Skorupski, Karen; Pellegrini, Maria; Chiorazzo, Michael G.; Taylor, Ronald K.; Kull, F. Jon (Dartmouth)

    2010-03-04

    Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 {angstrom} resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that cis-palmitoleic acid reduces TCP and CT expression in V. cholerae and prevents ToxT from binding to DNA in vitro provides a direct link between the host environment of V. cholerae and regulation of virulence gene expression.

  15. Proteolysis of virulence regulator ToxR is associated with entry of Vibrio cholerae into a dormant state.

    Directory of Open Access Journals (Sweden)

    Salvador Almagro-Moreno

    2015-04-01

    Full Text Available Vibrio cholerae O1 is a natural inhabitant of aquatic environments and causes the diarrheal disease, cholera. Two of its primary virulence regulators, TcpP and ToxR, are localized in the inner membrane. TcpP is encoded on the Vibrio Pathogenicity Island (VPI, a horizontally acquired mobile genetic element, and functions primarily in virulence gene regulation. TcpP has been shown to undergo regulated intramembrane proteolysis (RIP in response to environmental conditions that are unfavorable for virulence gene expression. ToxR is encoded in the ancestral genome and is present in non-pathogenic strains of V. cholerae, indicating it has roles outside of the human host. In this study, we show that ToxR undergoes RIP in V. cholerae in response to nutrient limitation at alkaline pH, a condition that occurs during the stationary phase of growth. This process involves the site-2 protease RseP (YaeL, and is dependent upon the RpoE-mediated periplasmic stress response, as deletion mutants for the genes encoding these two proteins cannot proteolyze ToxR under nutrient limitation at alkaline pH. We determined that the loss of ToxR, genetically or by proteolysis, is associated with entry of V. cholerae into a dormant state in which the bacterium is normally found in the aquatic environment called viable but nonculturable (VBNC. Strains that can proteolyze ToxR, or do not encode it, lose culturability, experience a change in morphology associated with cells in VBNC, yet remain viable under nutrient limitation at alkaline pH. On the other hand, mutant strains that cannot proteolyze ToxR remain culturable and maintain the morphology of cells in an active state of growth. Overall, our findings provide a link between the proteolysis of a virulence regulator and the entry of a pathogen into an environmentally persistent state.

  16. Genomic Features of Environmental and Clinical Vibrio parahaemolyticus Isolates Lacking Recognized Virulence Factors Are Dissimilar

    Science.gov (United States)

    Petronella, N.; Chew Leung, C.; Pightling, A. W.; Banerjee, S. K.

    2015-01-01

    Vibrio parahaemolyticus is a bacterial pathogen that can cause illness after the consumption or handling of contaminated seafood. The primary virulence factors associated with V. parahaemolyticus illness are thermostable direct hemolysin (TDH) and Tdh-related hemolysin (TRH). However, clinical strains lacking tdh and trh have recently been isolated, and these clinical isolates are poorly understood. To help understand the emergence of clinical tdh- and trh-negative isolates, a genomic approach was used to comprehensively compare 4 clinical tdh- and trh-negative isolates with 16 environmental tdh- and trh-negative isolates and 34 clinical isolates positive for tdh or trh, or both, with the objective of identifying genomic features that are unique to clinical tdh- and trh-negative isolates. The prevalence of pathogenicity islands (PAIs) common to clinical isolates was thoroughly examined in each of the clinical tdh- and trh-negative isolates. The tdh PAI was not present in any clinical or environmental tdh- and trh-negative isolates. The trh PAI was not present in any environmental isolates; however, in clinical tdh- and trh-negative isolate 10-4238, the majority of the trh PAI including a partial trh1 gene was present, which resulted in reclassification of this isolate as a tdh-negative and trh-positive isolate. In the other clinical tdh- and trh-negative isolates, neither the trh gene nor the trh PAI was present. We identified 862 genes in clinical tdh- and trh-negative isolates but not in environmental tdh- and trh-negative isolates. Many of these genes are highly homologous to genes found in common enteric bacteria and included genes encoding a number of chemotaxis proteins and a novel putative type VI secretion system (T6SS) effector and immunity protein (T6SS1). The availability of genome sequences from clinical V. parahaemolyticus tdh- and trh-negative isolates and the comparative analysis may help provide an understanding of how this pathotype is able to

  17. Vibrio vulnificus biotype 3 multifunctional autoprocessing RTX toxin is an adenylate cyclase toxin essential for virulence in mice.

    Science.gov (United States)

    Ziolo, Kevin J; Jeong, Hee-Gon; Kwak, Jayme S; Yang, Shuangni; Lavker, Robert M; Satchell, Karla J F

    2014-05-01

    Vibrio vulnificus is an environmental organism that causes both food-borne and wound infections with high morbidity and mortality in humans. The annual incidence and global distribution of infections associated with this pathogen are increasing with climate change. In the late 1990s, an outbreak of tilapia-associated wound infections in Israel was linked to a previously unrecognized variant of V. vulnificus designated biotype 3. The sudden emergence and clonality of the outbreak suggest that this strain may be a true newly emergent pathogen with novel virulence properties compared to those of other V. vulnificus strains. In a subcutaneous infection model to mimic wound infection, the multifunctional autoprocessing RTX (MARTX) toxin of biotype 3 strains was shown to be an essential virulence factor contributing to highly inflammatory skin wounds with severe damage affecting every tissue layer. We conducted a sequencing-based analysis of the MARTX toxin and found that biotype 3 MARTX toxin has an effector domain structure distinct from that of either biotype 1 or biotype 2. Of the two new domains identified, a domain similar to Pseudomonas aeruginosa ExoY was shown to confer adenylate cyclase activity on the MARTX toxin. This is the first demonstration that the biotype 3 MARTX toxin is essential for virulence and that the ExoY-like MARTX effector domain is a catalytically active adenylate cyclase.

  18. The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis.

    Science.gov (United States)

    Amaro, Carmen; Sanjuán, Eva; Fouz, Belén; Pajuelo, David; Lee, Chung-Te; Hor, Lien-I; Barrera, Rodolfo

    2015-06-01

    Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA13, a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically identical copies of rtxA13 are present in all biotype 2 strains regardless of the serovar, one in the virulence plasmid and the other in chromosome II. The plasmid also contains other genes involved in survival and growth in eel blood: vep07, a gene for an outer membrane (OM) lipoprotein involved in resistance to eel serum and vep20, a gene for an OM receptor specific for eel-transferrin and, probably, other related fish transferrins. All the three genes are highly conserved within biotype 2, which suggests that they are under a strong selective pressure. Interestingly, the three genes are related with transferable plasmids, which emphasizes the role of horizontal gene transfer in the evolution of V. vulnificus in nutrient-enriched aquatic environments, such as fish farms.

  19. Expression of Vibrio salmonicida virulence genes and immune response parameters in experimentally challenged Atlantic salmon (Salmo salar L.

    Directory of Open Access Journals (Sweden)

    Ane Mohn Bjelland

    2013-12-01

    Full Text Available The Gram-negative bacterium Vibrio salmonicida is the causative agent of cold-water vibriosis (CV, a hemorrhagic septicemia that primarily affects farmed Atlantic salmon (Salmo salar L.. The mechanisms of disease development, host specificity and adaptation, as well as the immunogenic properties of V. salmonicida are largely unknown. Therefore, to gain more knowledge on the pathogenesis of CV, 90 Atlantic salmon parr were injected intraperitonellay with 6 x 106 CFU of V. salmonicida LFI1238. Samples from blood and spleen tissue were taken at different time points throughout the challenge for gene expression analysis by two-step reverse transcription quantitative real-time polymerase chain reaction. Out of a panel of six housekeeping genes, accD, gapA and 16S rDNA were found to be the most suitable references for expression analysis in Vibrio salmonicida. The bacterial proliferation during challenge was monitored based on the expression of the 16S rRNA encoding gene. Before day 4, the concentrations of V. salmonicida in blood and spleen tissue demonstrated a lag phase. From day 4, the bacterial proliferation was exponential. The expression profiles of eight genes encoding potential virulence factors of V. salmonicida were studied. Surprisingly, all tested virulence genes were generally highest expressed in broth cultures compared to the in vivo samples. We hypothesize that this general muting of gene expression in vivo may be a strategy for V. salmonicida to hide from the host immune system. To further investigate this hypothesis, the expression profiles of eight genes encoding innate immune factors were analyzed. The results demonstrated a strong and rapid, but short-lasting innate immune response against V. salmonicida. These results suggest that the bacterium possesses mechanisms that inhibit and/or resist the salmon innate immune system until the host becomes exhausted of fighting the on-going and eventually overwhelming infection.

  20. Differences in the stress tolerances of Vibrio parahaemolyticus strains due to their source and harboring of virulence genes.

    Science.gov (United States)

    Hasegawa, Akio; Hara-Kudo, Yukiko; Ogata, Kikuyo; Saito, Shioko; Sugita-Konishi, Yoshiko; Kumagai, Susumu

    2013-08-01

    To investigate the diversity of stress tolerance levels in Vibrio parahaemolyticus, 200 V. parahaemolyticus strains isolated from various coastal environments, seafood, and human clinical cases were exposed to acid, low-osmolality, freezing-thawing, and heat stresses. Tolerance against acid stress was higher in the virulent (tdh- and/or trh-positive) strains than in the avirulent (tdh- and trh-negative) strains. Tolerance against low-osmolality, freezing-thawing, and heat stresses was higher in the clinical strains of tdh- and/or trh-positive V. parahaemolyticus than in the coastal environment- and seafood-originated strains of tdh and/or trh-positive V. parahaemolyticus. Tolerance against acid stress was higher in the strains isolated from coastal seawater at ≤15°C than in the strains isolated at ≥20°C. Tolerance against heat stress was higher in the avirulent strains than the virulent strains, and in the strains isolated from coastal seawater at ≥20°C than the strains isolated from coastal seawater at ≤15°C. Therefore, this study demonstrated that the diversity of stress tolerance levels in V. parahaemolyticus strains depended on their source and whether they harbored virulence genes. In particular, there was significantly greater tolerance against acid in the virulence gene-harboring strains and strains isolated from low-temperature seawater. Because the stress tolerances of V. parahaemolyticus have direct influences for the survival in environment and food, it is important for the prevention of foodborne infection to control the stress-tolerant strains.

  1. Vibrios associated with red tides caused by Mesodinium rubrum.

    OpenAIRE

    Romalde, J L; Barja, J L; Toranzo, A E

    1990-01-01

    Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxic...

  2. Accessory cholera enterotoxin (Ace), the third toxin of a Vibrio cholerae virulence cassette.

    OpenAIRE

    Trucksis, M; Galen, J E; Michalski, J; Fasano, A; Kaper, J B

    1993-01-01

    Vibrio cholerae causes the potentially lethal disease cholera through the elaboration of the intestinal secretogen cholera toxin. A second toxin of V. cholerae, Zot, decreases intestinal tissue resistance by modifying intercellular tight junctions. In this report, a third toxin of V. cholerae, Ace (accessory cholera enterotoxin), is described. Ace increases short-circuit current in Ussing chambers and causes fluid secretion in ligated rabbit ileal loops. The predicted protein sequence of Ace ...

  3. AI-2 quorum-sensing inhibitors affect the starvation response and reduce virulence in several Vibrio species, most likely by interfering with LuxPQ.

    Science.gov (United States)

    Brackman, Gilles; Celen, Shari; Baruah, Kartik; Bossier, Peter; Van Calenbergh, Serge; Nelis, Hans J; Coenye, Tom

    2009-12-01

    The increase of disease outbreaks caused by Vibrio species in aquatic organisms as well as in humans, together with the emergence of antibiotic resistance in Vibrio species, has led to a growing interest in alternative disease control measures. Quorum sensing (QS) is a mechanism for regulating microbial gene expression in a cell density-dependent way. While there is good evidence for the involvement of auto-inducer 2 (AI-2)-based interspecies QS in the control of virulence in multiple Vibrio species, only few inhibitors of this system are known. From the screening of a small panel of nucleoside analogues for their ability to disturb AI-2-based QS, an adenosine derivative with a p-methoxyphenylpropionamide moiety at C-3' emerged as a promising hit. Its mechanism of inhibition was elucidated by measuring the effect on bioluminescence in a series of Vibrio harveyi AI-2 QS mutants. Our results indicate that this compound, as well as a truncated analogue lacking the adenine base, block AI-2-based QS without interfering with bacterial growth. The active compounds affected neither the bioluminescence system as such nor the production of AI-2, but most likely interfered with the signal transduction pathway at the level of LuxPQ in V. harveyi. The most active nucleoside analogue (designated LMC-21) was found to reduce the Vibrio species starvation response, to affect biofilm formation in Vibrio anguillarum, Vibrio vulnificus and Vibrio cholerae, to reduce pigment and protease production in V. anguillarum, and to protect gnotobiotic Artemia from V. harveyi-induced mortality.

  4. Feeding truncated heat shock protein 70s protect Artemia franciscana against virulent Vibrio campbellii challenge.

    Science.gov (United States)

    Baruah, Kartik; Norouzitallab, Parisa; Shihao, Li; Sorgeloos, Patrick; Bossier, Peter

    2013-01-01

    The 70 kDa heat shock proteins (Hsp70s) are highly conserved in evolution, leading to striking similarities in structure and composition between eukaryotic Hsp70s and their homologs in prokaryotes. The eukaryotic Hsp70 like the DnaK (Escherichia coli equivalent Hsp70) protein, consist of three functionally distinct domains: an N-terminal 44-kDa ATPase portion, an 18-kDa peptide-binding domain and a C-terminal 10-kDa fragment. Previously, the amino acid sequence of eukaryotic (the brine shrimp Artemia franciscana) Hsp70 and DnaK proteins were shown to share a high degree of homology, particularly in the peptide-binding domain (59.6%, the putative innate immunity-activating portion) compared to the N-terminal ATPase (48.8%) and the C-terminal lid domains (19.4%). Next to this remarkable conservation, these proteins have been shown to generate protective immunity in Artemia against pathogenic Vibrio campbellii. This study, aimed to unravel the Vibrio-protective domain of Hsp70s in vivo, demonstrated that gnotobiotically cultured Artemia fed with recombinant C-terminal fragment (containing the conserved peptide binding domain) of Artemia Hsp70 or DnaK protein were well protected against subsequent Vibrio challenge. In addition, the prophenoloxidase (proPO) system, at both mRNA and protein activity levels, was also markedly induced by these truncated proteins, suggesting epitope(s) responsible for priming the proPO system and presumably other immune-related genes, consequently boosting Artemia survival upon challenge with V. campbellii, might be located within this conserved region of the peptide binding domain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Taxonomie et virulence de Vibrio pathogènes de Crassostrea gigas

    OpenAIRE

    Lazaille, Eric

    2003-01-01

    Le principal objectif de ce travail est l'étude d'un autre groupe de bactéries, le groupe J ; comportant les bactéries Mel 38, Mel 39 et Mel 40 . Dans un premier temps nous avons caractérisé les bactéries du groupe J au niveau taxonomique par des méthodes moléculaires. En effet, les outils biochimiques à notre disposition ne sont plus adaptés pour identifier les espèces de Vibrio marins. Les clés d'identification biochimiques d'Alsina et Blanch [ 9 1 sont dépassées car elles n'incluent pas la...

  6. Thiocarbamates from Moringa oleifera Seeds Bioactive against Virulent and Multidrug-Resistant Vibrio Species

    Science.gov (United States)

    de Sousa, Oscarina Viana; Hofer, Ernesto; Mafezoli, Jair; Barbosa, Francisco Geraldo

    2017-01-01

    Prospect of antibacterial agents may provide an alternative therapy for diseases caused by multidrug-resistant bacteria. This study aimed to evaluate the in vitro bioactivity of Moringa oleifera seed extracts against 100 vibrios isolated from the marine shrimp Litopenaeus vannamei. Ethanol extracts at low (MOS-E) and hot (MOS-ES) temperature are shown to be bioactive against 92% and 90% of the strains, respectively. The most efficient Minimum Inhibitory Concentration (MIC) levels of MOS-E and MOS-ES against a high percentage of strains were 32 µg mL−1. Bioguided screening of bioactive compounds showed that the ethyl acetate fraction from both extracts was the only one that showed antibacterial activity. Vibriocidal substances, niazirine and niazimicine, were isolated from the aforementioned fraction through chromatographic fractionation. PMID:28770224

  7. Complete Sequence of Virulence Plasmid pJM1 from the Marine Fish Pathogen Vibrio anguillarum Strain 775

    Science.gov (United States)

    Di Lorenzo, Manuela; Stork, Michiel; Tolmasky, Marcelo E.; Actis, Luis A.; Farrell, David; Welch, Timothy J.; Crosa, Lidia M.; Wertheimer, Anne M.; Chen, Qian; Salinas, Patricia; Waldbeser, Lillian; Crosa, Jorge H.

    2003-01-01

    The virulence plasmid pJM1 enables the fish pathogen Vibrio anguillarum, a gram-negative polarly flagellated comma-shaped rod bacterium, to cause a highly fatal hemorrhagic septicemic disease in salmonids and other fishes, leading to epizootics throughout the world. The pJM1 plasmid 65,009-nucleotide sequence, with an overall G+C content of 42.6%, revealed genes and open reading frames (ORFs) encoding iron transporters, nonribosomal peptide enzymes, and other proteins essential for the biosynthesis of the siderophore anguibactin. Of the 59 ORFs, approximately 32% were related to iron metabolic functions. The plasmid pJM1 confers on V. anguillarum the ability to take up ferric iron as a complex with anguibactin from a medium in which iron is chelated by transferrin, ethylenediamine-di(o-hydroxyphenyl-acetic acid), or other iron-chelating compounds. The fatDCBA-angRT operon as well as other downstream biosynthetic genes is bracketed by the homologous ISV-A1 and ISV-A2 insertion sequences. Other clusters on the plasmid also show an insertion element-flanked organization, including ORFs homologous to genes involved in the biosynthesis of 2,3-dihydroxybenzoic acid. Homologues of replication and partition genes are also identified on pJM1 adjacent to this region. ORFs with no known function represent approximately 30% of the pJM1 sequence. The insertion sequence elements in the composite transposon-like structures, corroborated by the G+C content of the pJM1 sequence, suggest a modular composition of plasmid pJM1, biased towards acquisition of modules containing genes related to iron metabolic functions. We also show that there is considerable microheterogeneity in pJM1-like plasmids from virulent strains of V. anguillarum isolated from different geographical sources. PMID:13129954

  8. Galleria mellonella as an infection model to investigate virulence of Vibrio parahaemolyticus.

    Science.gov (United States)

    Wagley, Sariqa; Borne, Richard; Harrison, Jamie; Baker-Austin, Craig; Ottaviani, Donatella; Leoni, Francesca; Vuddhakul, Varaporn; Titball, Richard W

    2017-09-29

    Non-toxigenic V. parahaemolyticus isolates (tdh-/trh-/T3SS2-) have recently been isolated from patients with gastroenteritis. In this study we report that the larvae of the wax moth (Galleria mellonella) are susceptible to infection by toxigenic or non-toxigenic clinical isolates of V. parahaemolyticus. In comparison larvae inoculated with environmental isolates of V. parahaemolyticus did not succumb to disease. Whole genome sequencing of clinical non-toxigenic isolates revealed the presence of a gene encoding a nudix hydrolase, identified as mutT. A V. parahaemolyticus mutT mutant was unable to kill G. mellonella at 24 h post inoculation, indicating a role of this gene in virulence. Our findings show that G. mellonella is a valuable model for investigating screening of possible virulence genes of V. parahaemolyticus and can provide new insights into mechanisms of virulence of atypical non-toxigenic V. parahaemolyticus. These findings will allow improved genetic tests for the identification of pathogenic V. parahaemolyticus to be developed and will have a significant impact for the scientific community.

  9. Galleria mellonella is low cost and suitable surrogate host for studying virulence of human pathogenic Vibrio cholerae.

    Science.gov (United States)

    Bokhari, Habib; Ali, Amjad; Noreen, Zobia; Thomson, Nicholas; Wren, Brendan W

    2017-09-10

    Vibrio cholerae causes a severe diarrheal disease affecting millions of people worldwide, particularly in low income countries. V. cholerae successfully persist in aquatic environment and its pathogenic strains results in sever enteric disease in humans. This dual life style contributes towards its better survival and persistence inside host gut and in the environment. Alternative animal replacement models are of great value in studying host-pathogen interaction and for quick screening of various pathogenic strains. One such model is Galleria mellonella, a wax moth which has a complex innate immune system and here we investigate its suitability as a model for clinical human isolates of O1 El TOR, Ogawa serotype belonging to two genetically distinct subclades found in Pakistan (PSC-1 and PSC-2). We demonstrate that the PSC-2 strain D59 frequently isolated from inland areas, was more virulent than PSC-1 strain K7 mainly isolated from coastal areas (p=0.0001). In addition, we compared the relative biofilm capability of the representative strains as indicators of their survival and persistence in the environment and K7 showed enhanced biofilm forming capabilities (p=0.004). Finally we present the annotated genomes of the strains D59 and K7, and compared them with the reference strain N16961. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Virulence Profiles of Vibrio vulnificus in German Coastal Waters, a Comparison of North Sea and Baltic Sea Isolates

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    Nadja Bier

    2015-12-01

    Full Text Available Vibrio vulnificus is a halophilic bacterium of coastal environments known for sporadically causing severe foodborne or wound infections. Global warming is expected to lead to a rising occurrence of V. vulnificus and an increasing incidence of human infections in Northern Europe. So far, infections in Germany were exclusively documented for the Baltic Sea coast, while no cases from the North Sea region have been reported. Regional variations in the prevalence of infections may be influenced by differences in the pathogenicity of V. vulnificus populations in both areas. This study aimed to compare the distribution of virulence-associated traits and genotypes among 101 V. vulnificus isolates from the Baltic Sea and North Sea in order to assess their pathogenicity potential. Furthermore, genetic relationships were examined by multilocus sequence typing (MLST. A high diversity of MLST sequences (74 sequence types and differences regarding the presence of six potential pathogenicity markers were observed in the V. vulnificus populations of both areas. Strains with genotypes and markers associated with pathogenicity are not restricted to a particular geographic region. This indicates that lack of reported cases in the North Sea region is not caused by the absence of potentially pathogenic strains.

  11. A Bistable Switch and Anatomical Site Control Vibrio cholerae Virulence Gene Expression in the Intestine

    DEFF Research Database (Denmark)

    Nielsen, Alex Toftgaard; Dolganov, N. A.; Rasmussen, Thomas

    2010-01-01

    master regulator of virulence gene expression also exhibited the bifurcation phenotype. The bifurcation phenotype was found to be reversible, epigenetic and to persist after removal of bicarbonate, features consistent with bistable switches. The bistable switch requires the positive-feedback circuit...... controlling ToxT expression and formation of the CRP-cAMP complex during entry into stationary phase. Key features of this bistable switch also were demonstrated in vivo, where striking heterogeneity in tcpA expression was observed in luminal fluid in later stages of the infection. When this fluid was diluted...

  12. Virulence factors in environmental and clinical Vibrio cholerae from endemic areas in Kenya

    Directory of Open Access Journals (Sweden)

    Racheal W. Kimani

    2014-04-01

    Full Text Available Background: Since 1971, Kenya has had repeated cholera outbreaks. However, the cause of seasonal epidemics of cholera is not fully understood and neither are the factors that drive epidemics, both in Kenya and globally.Objectives: The objectives of the study were to determine the environmental reservoirs of V. cholerae during an interepidemic period in Kenya and to characterise their virulence factors.Methods: One hundred (50 clinical, 50 environmental samples were tested for V. cholerae isolates using both simplex and multiplex polymerase chain reaction.Results: Both sediments and algae from fishing and landing bays yielded isolates of V. cholerae. Clinical strains were characterised along with the environmental strains for comparison. All clinical strains harboured ctxA, tcpA (El Tor, ompU, zot, ace, toxR, hylA (El Tor and tcpI genes. Prevalence for virulence genes in environmental strains was hylA (El Tor (10%, toxR (24%, zot (22%, ctxA (12%,tcpI (8%, hylA (26% and tcpA (12%.Conclusion: The study sites, including landing bays and beaches, contained environmental V. cholerae, suggesting that these may be reservoirs for frequent epidemics. Improved hygiene and fish-handling techniques will be important in reducing the persistence of reservoirs.

  13. Comparative genomics of pathogenic lineages of Vibrio nigripulchritudo identifies virulence-associated traits.

    Science.gov (United States)

    Goudenège, David; Labreuche, Yannick; Krin, Evelyne; Ansquer, Dominique; Mangenot, Sophie; Calteau, Alexandra; Médigue, Claudine; Mazel, Didier; Polz, Martin F; Le Roux, Frédérique

    2013-10-01

    Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively pathogenic isolates from septicemic shrimp in Madagascar. The similar genetic distance between the three clades indicates that they have diverged from an ancestral population roughly at the same time and recombination analysis indicates that these genomes have, in the past, shared a common gene pool and exchanged genes. As each contemporary lineage is comprised of nearly identical strains, comparative genomics allowed differentiation of genetic elements specific to shrimp pathogenesis of varying severity. Notably, only a large plasmid present in all highly pathogenic (HP) strains encodes a toxin. Although less/non-pathogenic strains contain related plasmids, these are differentiated by a putative toxin locus. Expression of this gene by a non-pathogenic V. nigripulchritudo strain resulted in production of toxic culture supernatant, normally an exclusive feature of HP strains. Thus, this protein, here termed 'nigritoxin', is implicated to an extent that remains to be precisely determined in the toxicity of V. nigripulchritudo.

  14. Glucose- but not rice-based oral rehydration therapy enhances the production of virulence determinants in the human pathogen Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Juliane Kühn

    2014-12-01

    Full Text Available Despite major attempts to prevent cholera transmission, millions of people worldwide still must address this devastating disease. Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT, whereby water and electrolytes are replenished. Commonly distributed oral rehydration salts also contain glucose. Here, we analyzed the effects of glucose and alternative carbon sources on the production of virulence determinants in the causative agent of cholera, the bacterium Vibrio cholerae during in vitro experimentation. We demonstrate that virulence gene expression and the production of cholera toxin are enhanced in the presence of glucose or similarly transported sugars in a ToxR-, TcpP- and ToxT-dependent manner. The virulence genes were significantly less expressed if alternative non-PTS carbon sources, including rice-based starch, were utilized. Notably, even though glucose-based ORT is commonly used, field studies indicated that rice-based ORT performs better. We therefore used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORT could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti. Our results strongly support a change of carbon source for the treatment of cholera, especially in epidemic settings.

  15. Glucose- but not rice-based oral rehydration therapy enhances the production of virulence determinants in the human pathogen Vibrio cholerae.

    Science.gov (United States)

    Kühn, Juliane; Finger, Flavio; Bertuzzo, Enrico; Borgeaud, Sandrine; Gatto, Marino; Rinaldo, Andrea; Blokesch, Melanie

    2014-12-01

    Despite major attempts to prevent cholera transmission, millions of people worldwide still must address this devastating disease. Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT), whereby water and electrolytes are replenished. Commonly distributed oral rehydration salts also contain glucose. Here, we analyzed the effects of glucose and alternative carbon sources on the production of virulence determinants in the causative agent of cholera, the bacterium Vibrio cholerae during in vitro experimentation. We demonstrate that virulence gene expression and the production of cholera toxin are enhanced in the presence of glucose or similarly transported sugars in a ToxR-, TcpP- and ToxT-dependent manner. The virulence genes were significantly less expressed if alternative non-PTS carbon sources, including rice-based starch, were utilized. Notably, even though glucose-based ORT is commonly used, field studies indicated that rice-based ORT performs better. We therefore used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORT could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti. Our results strongly support a change of carbon source for the treatment of cholera, especially in epidemic settings.

  16. Molecular, serological, and virulence characteristics of Vibrio parahaemolyticus isolated from environmental, food, and clinical sources in North America and Asia.

    Science.gov (United States)

    DePaola, Angelo; Ulaszek, Jodie; Kaysner, Charles A; Tenge, Bradley J; Nordstrom, Jessica L; Wells, Joy; Puhr, Nancy; Gendel, Steven M

    2003-07-01

    Potential virulence attributes, serotypes, and ribotypes were determined for 178 pathogenic Vibrio parahaemolyticus isolates from clinical, environmental, and food sources on the Pacific, Atlantic, and Gulf Coasts of the United States and from clinical sources in Asia. The food and environmental isolates were generally from oysters, and they were defined as being pathogenic by using DNA probes to detect the presence of the thermostable direct hemolysin (tdh) gene. The clinical isolates from the United States were generally associated with oyster consumption, and most were obtained from outbreaks in Washington, Texas, and New York. Multiplex PCR was used to confirm the species identification and the presence of tdh and to test for the tdh-related hemolysin trh. Most of the environmental, food, and clinical isolates from the United States were positive for tdh, trh, and urease production. Outbreak-associated isolates from Texas, New York, and Asia were predominantly serotype O3:K6 and possessed only tdh. A total of 27 serotypes and 28 ribogroups were identified among the isolates, but the patterns of strain distribution differed between the serotypes and ribogroups. All but one of the O3:K6 isolates from Texas were in a different ribogroup from the O3:K6 isolates from New York or Asia. The O3:K6 serotype was not detected in any of the environmental and food isolates from the United States, and none of the food or environmental isolates belonged to any of the three ribogroups that contained all of the O3:K6 and related clinical isolates. The combination of serotyping and ribotyping showed that the Pacific Coast V. parahaemolyticus population appeared to be distinct from that of either the Atlantic Coast or Gulf Coast. The fact that certain serotypes and ribotypes contained both clinical and environmental isolates while many others contained only environmental isolates implies that certain serotypes or ribotypes are more relevant for human disease.

  17. Efek Antibakteri Ekstrak Daun Mimba (Azadirachta indica A. Juss terhadap Bakteri Vibrio algynoliticus Secara In Vitro

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    Uli Ayini

    2014-03-01

    Full Text Available Budidaya udang windu di Indonesia telah berkembang pesat. Salah satu kendala budidaya udang adalah penyakit Vibriosis yang disebabkan oleh bakteri Vibrio algynoliticus. Tujuan penelitian ini adalah untuk mengetahui efek antibakeri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus. Penelitian ini menggunakan metode dilusi untuk mengetahui efek antibakteri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus secara in vitro. Konsentrasi ekstrak yang digunakan (% yaitu: 0; 2,5; 5; 7,5; 10; 12,5 dan sebagai kontrol terdiri dari kontrol positif, dan kontrol negatif. Pengumpulan data untuk menentukan MIC (Minimum Inhibitory Concentration dilakukan dengan membandingkan kejernihan kultur di medium TSB 2% pada berbagai konsentrasi yang berbeda, dengan kontrol positif dan kontrol negatif. Penentuan MBC (Minimum Bacterisidal Concentration dilakukan dengan melihat ada tidaknya dan jumlah koloni bakteri Vibrio alginolyticus yang muncul pada medium subkultur TSA 2% setelah inkubasi 24 jam. Hasil penelitian menunjukkan nilai MIC yaitu konsentrasi 5%, hal ini ditunjukkan dengan tabung yang mulai jernih. Nilai MBC ekstrak daun mimba terhadap bakteri Vibrio alginolyticus adalah konsentrasi 12,5% ditandai dengan sudah tidak munculnya  koloni bakteri Vibrio alginolyticus. Berdasarkan penelitian ini dapat disimpulkan bahwa ekstrak daun mimba dapat memberikan efek antibakteri terhadap bakteri Vibrio alginolyticus secara in vitro.Tiger shrimp cultivation in Indonesia has been growing rapidly. The main obstacle is the shrimp farming vibriosis disease caused by the bacterium Vibrio algynoliticus. The aim of this research was to determine the effects of neem leaf extract antibakeri against Vibrio algynoliticus. This study used a dilution method to determine the antibacterial effect of neem leaf extract against Vibrio algynoliticus bacteria in vitro. The concentration of the extract used (%: 0; 2.5; 5; 7.5; 10; 12.5 and as a control consisting of a positive

  18. Virulence-associated factors in Vibrio cholerae non-O1/non-O139 and V. mimicus strains isolated in ornamental fish species.

    Science.gov (United States)

    Zago, V; Zambon, M; Civettini, M; Zaltum, O; Manfrin, A

    2017-12-01

    During recent decades, ornamental fish have proven to be one of the fastest growing categories of pets in Europe. In this framework, we evaluated both the potential pathogenic and zoonotic risks caused by 53 Vibrio cholerae non-O1/non-O139 and a Vibrio mimicus strain isolated from ornamental fish species mostly originating from South-East Asia countries between 2000 and 2015 in Italy. All the strains were firstly identified at species level by biochemical, phylogenetic and mass spectrometry (matrix-assisted laser desorption ionization time of flight) methods, and then studied to reveal the presence of the main virulence and colonization-associated factors, as ctxA, ace, zot, stn/sto, toxR, rtxA, hlyA and tcpA by multiplex and single endpoint PCR assays. Findings showed that 21 of 54 strains harboured at least one virulence factor with a predominance for the toxR+ , rtxA+ and hlyAET+ genotype. Interestingly, the V. mimicus strain harboured the colonization factor and the CTX prophage receptor, tcpA, indicating the ability to capture and integrate it in its genome increasing its pathogenicity. Although these enterotoxins can sporadically cause gastroenteritis, the results highlight their probable involvement in causing severe implications for public health, suggesting the need for an European microbiological monitoring. © 2017 John Wiley & Sons Ltd.

  19. Factors associated with virulence and survival in environmental and clinical isolates of Vibrio cholerae O1 and non O1 in Romania.

    Science.gov (United States)

    Israil, Anca; Balotescu, Carmen; Bucurenci, Nadia; Năcescu, Nadia; Cedru, Claudia; Popa, Cornelia; Ciufecu, C

    2003-01-01

    Four hundred ninety seven strains of Vibrio cholerae selected from isolates in Romania in the last decade 1990-1999 were investigated for antibiotic resistance and for classical and putative virulence factors. V. cholerae O1 strains predominated in clinical cases and non O1 strains in the environment, excepting in 1992 when non O1 strains were frequent in clinical and environmental sources. V. cholerae O1 strains previously susceptible to tetracycline acquired clinically significant resistance to this drug during 1993-1994, but this trend was reversed in 1995, following the introduction of nalidixic acid in cholera treatment in 1994. V. cholerae O1 and non O1 clinical isolates acquired simultaneous resistance to the vibriostatic agent O/129 and cotrimoxazole during 1994-1995. High levels of intrinsic resistance to multiple antibiotics were exhibited by all strains examined. The presence of cholera toxin (CT) was concentrated in clinical V. cholerae O1 strains and was substituted in clinical non O1 strains by four putative virulence markers (Kanagawa haemolysin, slime, lipase, and colonial opacity). Colonial opacity (30%) was present only in clinical isolates of V. cholerae non O1. Pigmentogenesis (11.7%) has present only in environmental sources. Antibioresistance profiles differ for V. cholerae O1 and non O1 strains with respect to their source of isolation. This aspect may imply a role in virulence and survival of V. cholerae in the natural environment where they may serve as a reservoir of virulence and multiple drug resistance genes.

  20. Effects of Pollution on Vibrios in Woji River OJESANMI, A S; IBE, S N ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: The effect of pollution on Vibrio spp. in five sampling stations along Woji River in Port. Harcourt was studied in the months of April and November 2010. Vibrio vulnificus, V. parahaemolyticus and V. alginolyticus were isolated. The Plate count technique on Thiosulphate Citrate Bile Salt agar revealed a high.

  1. Effects of Pollution on Vibrios in Woji River | Ojesanmi | Journal of ...

    African Journals Online (AJOL)

    The effect of pollution on Vibrio spp. in five sampling stations along Woji River in Port Harcourt was studied in the months of April and November 2010. Vibrio vulnificus, V. parahaemolyticus and V. alginolyticus were isolated. The Plate count technique on Thiosulphate Citrate Bile Salt agar revealed a high population density ...

  2. Vibrios associated with red tides caused by Mesodinium rubrum.

    Science.gov (United States)

    Romalde, J L; Barja, J L; Toranzo, A E

    1990-11-01

    Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxicity assays conducted in different poikilothermic and homoiothermic cell lines showed that cytotoxin production was not necessarily associated with the species selected during the red tides.

  3. Does Virulence Assessment of Vibrio anguillarum Using Sea Bass (Dicentrarchus labrax) Larvae Correspond with Genotypic and Phenotypic Characterization?

    DEFF Research Database (Denmark)

    Frans, Ingeborg; Dierckens, Kristof; Crauwels, Sam

    2013-01-01

    or phenotypic characteristics, illustrating the complexity of V. anguillarum virulence. Moreover, the standardized gnotobiotic system used in this study has proven its strength as a model to assess and compare the virulence of different V. anguillarum strains in vivo. In this way, the bioassay contributes...

  4. Neutralization of radical toxicity by temperature-dependent modulation of extracellular SOD activity in coral bleaching pathogen Vibrio shiloi and its role as a virulence factor.

    Science.gov (United States)

    Murali, Malliga Raman; Raja, Subramaniya Bharathi; Devaraj, Sivasitambaram Niranjali

    2010-08-01

    Vibrio shiloi is the first and well-documented bacterium which causes coral bleaching, particularly, during summer, when seawater temperature is between 26 and 31 degrees C. Coral bleaching is the disruption of the symbiotic association between coral hosts and their photosynthetic microalgae zooxanthellae. This is either due to lowered resistance in corals to infection or increased virulence of the bacterium at the higher sea surface temperature. The concentration of the oxygen and resulting oxygen radicals produced by the zooxanthellae during photosynthesis are highly toxic to bacteria, which also assist corals in resisting the infection. Hence, in this study we examined the effect of different temperatures on the activity of a novel extracellular SOD in V. shiloi. We also partially characterized the SOD and clearly confirmed that the extracellular SOD produced by V. shiloi is Mn-SOD type, as it was not inhibited by H2O2 or KCN. Performing chemical susceptibility killing assay, we confirmed that extracellular SOD may act as first line of defense for the bacteria against the reactive oxygen species. Since, increased activity of novel Mn-SOD at higher temperature, leads to the neutralization of radical toxicity and facilitates the survival of V. shiloi. Hence, the extracellular Mn-SOD may be considered as a virulence factor.

  5. Bile acid-induced virulence gene expression of Vibrio parahaemolyticus reveals a novel therapeutic potential for bile acid sequestrants.

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Gotoh

    Full Text Available Vibrio parahaemolyticus, a bacterial pathogen, causes human gastroenteritis. A type III secretion system (T3SS2 encoded in pathogenicity island (Vp-PAI is the main contributor to enterotoxicity and expression of Vp-PAI encoded genes is regulated by two transcriptional regulators, VtrA and VtrB. However, a host-derived inducer for the Vp-PAI genes has not been identified. Here, we demonstrate that bile induces production of T3SS2-related proteins under osmotic conditions equivalent to those in the intestinal lumen. We also show that bile induces vtrA-mediated vtrB transcription. Transcriptome analysis of bile-responsive genes revealed that bile strongly induces expression of Vp-PAI genes in a vtrA-dependent manner. The inducing activity of bile was diminished by treatment with bile acid sequestrant cholestyramine. Finally, we demonstrate an in vivo protective effect of cholestyramine on enterotoxicity and show that similar protection is observed in infection with a different type of V. parahaemolyticus or with non-O1/non-O139 V. cholerae strains of vibrios carrying the same kind of T3SS. In summary, these results provide an insight into how bacteria, through the ingenious action of Vp-PAI genes, can take advantage of an otherwise hostile host environment. The results also reveal a new therapeutic potential for widely used bile acid sequestrants in enteric bacterial infections.

  6. Genomic taxonomy of vibrios

    Directory of Open Access Journals (Sweden)

    Iida Tetsuya

    2009-10-01

    Full Text Available Abstract Background Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera from 32 genome sequences of different vibrio species. We use a variety of tools to explore the taxonomic relationship between the sequenced genomes, including Multilocus Sequence Analysis (MLSA, supertrees, Average Amino Acid Identity (AAI, genomic signatures, and Genome BLAST atlases. Our aim is to analyse the usefulness of these tools for species identification in vibrios. Results We have generated four new genome sequences of three Vibrio species, i.e., V. alginolyticus 40B, V. harveyi-like 1DA3, and V. mimicus strains VM573 and VM603, and present a broad analyses of these genomes along with other sequenced Vibrio species. The genome atlas and pangenome plots provide a tantalizing image of the genomic differences that occur between closely related sister species, e.g. V. cholerae and V. mimicus. The vibrio pangenome contains around 26504 genes. The V. cholerae core genome and pangenome consist of 1520 and 6923 genes, respectively. Pangenomes might allow different strains of V. cholerae to occupy different niches. MLSA and supertree analyses resulted in a similar phylogenetic picture, with a clear distinction of four groups (Vibrio core group, V. cholerae-V. mimicus, Aliivibrio spp., and Photobacterium spp.. A Vibrio species is defined as a group of strains that share > 95% DNA identity in MLSA and supertree analysis, > 96% AAI, ≤ 10 genome signature dissimilarity, and > 61% proteome identity. Strains of the same species and species of the same genus will form monophyletic groups on the basis of MLSA and supertree. Conclusion The combination of different analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in

  7. Food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of Vibrio parahaemolyticus in Korea from 2003 to 2016: a review

    Directory of Open Access Journals (Sweden)

    Kunbawui Park

    2018-02-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003–2016. Main body V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003–2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin or trh (tdh-related hemolysin genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

  8. Characterization of Vibrio cholerae O1 El Tor biotype variant clinical isolates from Bangladesh and Haiti, including a molecular genetic analysis of virulence genes.

    Science.gov (United States)

    Son, Mike S; Megli, Christina J; Kovacikova, Gabriela; Qadri, Firdausi; Taylor, Ronald K

    2011-11-01

    Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains.

  9. Characterization of Vibrio cholerae O1 El Tor Biotype Variant Clinical Isolates from Bangladesh and Haiti, Including a Molecular Genetic Analysis of Virulence Genes ▿

    Science.gov (United States)

    Son, Mike S.; Megli, Christina J.; Kovacikova, Gabriela; Qadri, Firdausi; Taylor, Ronald K.

    2011-01-01

    Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains. PMID:21880975

  10. The Fatty Acid Regulator FadR Influences the Expression of the Virulence Cascade in the El Tor Biotype of Vibrio cholerae by Modulating the Levels of ToxT via Two Different Mechanisms.

    Science.gov (United States)

    Kovacikova, Gabriela; Lin, Wei; Taylor, Ronald K; Skorupski, Karen

    2017-04-01

    FadR is a master regulator of fatty acid (FA) metabolism that coordinates the pathways of FA degradation and biosynthesis in enteric bacteria. We show here that a ΔfadR mutation in the El Tor biotype of Vibrio cholerae prevents the expression of the virulence cascade by influencing both the transcription and the posttranslational regulation of the master virulence regulator ToxT. FadR is a transcriptional regulator that represses the expression of genes involved in FA degradation, activates the expression of genes involved in unsaturated FA (UFA) biosynthesis, and also activates the expression of two operons involved in saturated FA (SFA) biosynthesis. Since FadR does not bind directly to the toxT promoter, we determined whether the regulation of any of its target genes indirectly influenced ToxT. This was accomplished by individually inserting a double point mutation into the FadR-binding site in the promoter of each target gene, thereby preventing their activation or repression. Although preventing FadR-mediated activation of fabA, which encodes the enzyme that carries out the first step in UFA biosynthesis, did not significantly influence either the transcription or the translation of ToxT, it reduced its levels and prevented virulence gene expression. In the mutant strain unable to carry out FadR-mediated activation of fabA, expressing fabA ectopically restored the levels of ToxT and virulence gene expression. Taken together, the results presented here indicate that V. cholerae FadR influences the virulence cascade in the El Tor biotype by modulating the levels of ToxT via two different mechanisms.IMPORTANCE Fatty acids (FAs) play important roles in membrane lipid homeostasis and energy metabolism in all organisms. In Vibrio cholerae, the causative agent of the acute intestinal disease cholera, they also influence virulence by binding into an N-terminal pocket of the master virulence regulator, ToxT, and modulating its activity. FadR is a transcription factor

  11. Prevalence and diversity of Aeromonas and Vibrio spp. in coastal waters of Southern Italy

    DEFF Research Database (Denmark)

    Dumontet, S.; Krovacek, K.; Svenson, S.B.

    2000-01-01

    % of samples were positive for Vibrio spp. It was interesting to note that 38% of the positive stations for both Aeromonas and Vibrio spp. showed a fecal coliform contamination of water at ... coliforms) do not always satisfactorily reflect the hygienic quality of water. The presence of Vibrionaceae on copepods was also investigated. Copepods were sampled at a station located inside the harbour of the city of Naples and were found contaminated by V. cholerae non-Ol, V. alginolyticus, V. fluvialis...

  12. Exploring insights for virulent gene inhibition of multidrug resistant Salmonella typhi, Vibrio cholerae, and Staphylococcus areus by potential phytoligands via in silico screening.

    Science.gov (United States)

    Skariyachan, Sinosh; Jayaprakash, Nisha; Bharadwaj, Navya; Narayanappa, Rajeswari

    2014-01-01

    In our recent studies on prevalence of multidrug resistant pathogens in Byramangala reservoir, Karnataka, India, we identified Salmonella typhi, Staphylococcus aureus, and Vibrio cholerae which had acquired multiple drug resistance (MDR) and emerged as superbugs. Hence, there is a pressing demand to identify alternative therapeutic remedies. Our study focused on the screening of herbal leads by structure-based virtual screening. The virulent gene products of these pathogens towards Kanamycin(aph), Trimethoprim(dfrA1), Methicillin (mecI), and Vancomycin (vanH) were identified as the probable drug targets and their 3D structures were predicted by homology modeling. The predicted models showed good stereochemical validity. By extensive literature survey, we selected 58 phytoligands and their drug likeliness and pharmacokinetic properties were computationally predicted. The inhibitory properties of these ligands against drug targets were studied by molecular docking. Our studies revealed that Baicalein from S. baicalensis (baikal skullcap) and Luteolin from Taraxacum officinale (dandelion) were identified as potential inhibitors against aph of S. typhi. Resveratrol from Vitis vinifera (grape vine) and Wogonin from S. baicalensis were identified as potential inhibitors against dfrA1 of S. typhi. Herniarin from Herniaria glabra (rupture worts) and Pyrocide from Daucus carota (Carrot) were identified as the best leads against dfrA1 of V. cholerae. Taraxacin of T. officinale (weber) and Luteolin were identified as potential inhibitors against Mec1. Apigenin from Coffee arabica (coffee) and Luteolin were identified as the best leads against vanH of S. aureus. Our findings pave crucial insights for exploring alternative therapeutics against MDR pathogens.

  13. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River Estuary, China.

    Science.gov (United States)

    Song, Yuze; Yu, Pan; Li, Bailin; Pan, Yingjie; Zhang, Xiaojun; Cong, Jian; Zhao, Yinying; Wang, Hua; Chen, Lanming

    2013-09-30

    The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. This study constitutes the first investigation of ICEs-positive Vibrio spp. in the Yangze River Estuary, China

  14. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River estuary, China

    Science.gov (United States)

    2013-01-01

    Background The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. Results The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. Conclusions This study constitutes the first investigation of ICEs-positive Vibrio spp. in the

  15. Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico

    Science.gov (United States)

    Zavala-Norzagaray, Alan A.; Aguirre, A. Alonso; Velazquez-Roman, Jorge; Flores-Villaseñor, Héctor; León-Sicairos, Nidia; Ley-Quiñonez, C. P.; Hernández-Díaz, Lucio De Jesús; Canizalez-Roman, Adrian

    2015-01-01

    The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh+ gene) and 2/17 (11.7%) had the pandemic clone (tdh+ and toxRS/new+). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico. PMID:26161078

  16. Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico.

    Science.gov (United States)

    Zavala-Norzagaray, Alan A; Aguirre, A Alonso; Velazquez-Roman, Jorge; Flores-Villaseñor, Héctor; León-Sicairos, Nidia; Ley-Quiñonez, C P; Hernández-Díaz, Lucio De Jesús; Canizalez-Roman, Adrian

    2015-01-01

    The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh (+) gene) and 2/17 (11.7%) had the pandemic clone (tdh (+) and toxRS/new (+)). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.

  17. Isolation, Characterization, and Antibiotic Resistance of Vibrio spp. in Sea Turtles from Northwestern Mexico

    Directory of Open Access Journals (Sweden)

    Alan A. eZavala-Norzagaray

    2015-06-01

    Full Text Available The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL, Baja California Sur, Mexico (Pacific Ocean and the lagoon system of Navachiste (LSN and Marine Area of Influence (MAI, Guasave, Sinaloa (Gulf of California. A total of 34 black turtles (Chelonia mydas agassizii were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%, V. parahaemolyticus in 17/64 (26% and V. cholerae in 6/64 (9%,. However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI. Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4% belonged to the pathogenic strains (tdh+ gene and 2/17 (11.7% had the pandemic clone (tdh+ and toxRS/new+. Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66% the accessory cholera enterotoxin gene (ace was identified but without virulence gene zot, ctxA and ctxB. Of the isolated V. parahaemolyticus, V. cholerae and V. alginolyticus strains, 94.1%, 33.4% and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin, respectively. In conclusion, the presence of several potential (toxigenic human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.

  18. Vibrio and Pregnancy

    Science.gov (United States)

    ... 2013. Vibrio Infection. [Accessed January 2015]. Available at URL: http: / / www. cdc. gov/ vibrio/ index. html Centers for ... 2013. Vibrio parahaemolyticus. [Accessed January 2015]. Available at URL: http: / / www. cdc. gov/ vibrio/ vibriop. html Centers for ...

  19. Application of Reverse Transcriptase-PCR-DGGE as a rapid method for routine determination of Vibrio spp. in foods.

    Science.gov (United States)

    Chahorm, Kanchana; Prakitchaiwattana, Cheunjit

    2018-01-02

    The aim of this research was to evaluate the feasibility of PCR-DGGE and Reverse Transcriptase-PCR-DGGE techniques for rapid detection of Vibrio species in foods. Primers GC567F and 680R were initially evaluated for amplifying DNA and cDNA of ten references Vibrio species by PCR method. The GC-clamp PCR amplicons were separated according to their sequences by the DGGE using 10% (w/v) polyacrylamide gel containing 45-70% urea and formamide denaturants. Two pair of Vibrio species, which could not be differentiated on the gel, was Vibrio fluvialis - Vibrio furnissii and Vibrio parahaemolyticus - Vibrio harveyi. To determine the detection limit, in the community of 10 reference strains containing the same viable population, distinct DNA bands of 3 species; Vibrio cholerae, Vibrio mimicus and Vibrio alginolyticus were consistently observed by PCR-DGGE technique. In fact, 5 species; Vibrio cholerae, Vibrio mimicus, Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio fluvialis consistently observed by Reverse Transcriptase-PCR-DGGE. In the community containing different viable population increasing from 10 2 to 10 5 CFU/mL, PCR-DGGE analysis only detected the two most prevalent species, while RT-PCR-DGGE detected the five most prevalent species. Therefore, Reverse Transcriptase-PCR-DGGE was also selected for detection of various Vibrio cell conditions, including viable cell (VC), injured cells from frozen cultures (IVC) and injured cells from frozen cultures with pre-enrichment (PIVC). It was found that cDNA band of all cell conditions gave the same migratory patterns, except that multiple cDNA bands of Plesiomonas shigelloides under IVC and PIVC conditions were found. When Reverse Transcriptase-PCR-DGGE was used for detecting Vibrio parahaemolyticus in the pathogen-spiked food samples, Vibrio parahaemolyticus could be detected in the spiked samples containing at least 10 2 CFU/g of this pathogen. The results obtained also corresponded to standard method (USFDA, 2004

  20. Vibrio diseases of marine fish populations

    Science.gov (United States)

    Colwell, R. R.; Grimes, D. J.

    1984-03-01

    Several Vibrio spp. cause disease in marine fish populations, both wild and cultured. The most common disease, vibriosis, is caused by V. anguillarum. However, increase in the intensity of mariculture, combined with continuing improvements in bacterial systematics, expands the list of Vibrio spp. that cause fish disease. The bacterial pathogens, species of fish affected, virulence mechanisms, and disease treatment and prevention are included as topics of emphasis in this review.

  1. Virulence factors of non-O1 non-O139 Vibrio cholerae isolated in Córdoba, Argentina Factores de virulencia de Vibrio cholerae no-O1 no-O139 aislados en Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    C. Bidinost

    2004-12-01

    Full Text Available V. cholerae non-O1 non-O139 serogroups isolated from clinical and environmental sources in Córdoba, Argentina, were analyzed for the presence and expression of virulence genes. Most of the strains studied contained the genes toxR and hlyA, but lacked ctxA, zot, ace, tcpA and stn. The culture supernatants were tested for hemolytic and cytotoxic activity. The enterotoxic potential of the strains was studied in a rabbit ileal loop assay and their genetic profiles were compared by PFGE. The environmental strains varied in their virulence phenotype and showed no-clonal relationships. The clinical strains were highly enterotoxic, hemolytic, proteolytic and showed indistinguishable PFGE profiles, although they differed in their cytotoxic activity. This is the first description, using cell culture and “in vivo” studies, of the virulence properties of non-O1 non-O139 V. cholerae from Argentina.En este trabajo se analizó la presencia y expresión de genes de virulencia en V. cholerae no-O1 no-O139 de origen clínico y ambiental, aislados en Córdoba, Argentina. La mayoría de las cepas estudiadas contiene los genes toxR y hlyA, pero no ctxA, zot, ace, tcpA y stn. Se analizó la actividad hemolítica y citotóxica de estas cepas en los sobrenadantes de cultivo, así como su potencial enterotóxico en ensayos de asa ileal ligada de conejo. Además, los aislamientos fueron comparados por sus perfiles genéticos en PFGE. Las cepas del medio ambiente mostraron variación en su fenotipo de virulencia y no mostraron relación clonal. Las cepas clínicas fueron muy enterotóxicas, hemolíticas, proteolíticas y mostraron perfiles indistinguibles de PFGE, aunque mostraron diferencias en su actividad citotóxica. En este trabajo se describen por primera vez, utilizando ensayos de cultivo celular e “in vivo”, propiedades de virulencia de V. cholerae no-O1 no-O139 aislados en Argentina.

  2. Determination of several potential virulence factors in non-o1 Vibrio cholerae, Pseudomonas aeruginosa, faecal coliforms and streptococci isolated from Marrakesh groundwater.

    Science.gov (United States)

    Lamrani Alaoui, Hafsa; Oufdou, Khalid; Mezrioui, Nour-Eddine

    2010-01-01

    The dynamic, hemolytic and hemagglutination activities and the antibiotic resistance of non-O1 Vibrio cholerae, Pseudomonas aeruginosa, faecal coliforms (FC) and faecal streptococci (FS), isolated by standard membrane filtration methods from suburban and rural groundwater supplies, were carried out. Detectable non-O1 V. cholerae and P. aeruginosa was present in 81% and 88% of samples. The total occurrence of FC and FS during the period of study was 94%. The annual average densities of non-O1 V. cholerae were 4,903 MPN/100 mL. While, they were 206, 1,891 and 1,246 cfu/100 mL for P. aeruginosa, FC and FS respectively. Non-O1 V. cholerae strains had the highest percentage of hemolytic activities (alpha + beta) (71.29%), whereas 20.71% of FS, 16.88% of FC and 9.13% of P. aeruginosa strains produced hemolysin. Bacterial strains isolated were found to be adhesive, with percentages of 63.09%, 65.09%, 84.06% and 87.98% respectively for non-O1 V. cholerae, FS, FC and P. aeruginosa. As for antibiotic resistance, the overall resistance of non-O1 V. cholerae strains was 79%, whereas it was 100% for the other bacteria. Non-O1 V. cholerae resistance was expressed towards sulfamethoxazole (75%), streptomycin (62%) and cephalothin (60%). Obtained results indicated correlation between bacteriological pollution and their public health implications.

  3. Biological deinking of inkjet-printed paper using Vibrio alginolyticus and its enzymes

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; Raghukumar, C.

    broth was not effective in deinking. However, when the culture was grown in nutrient broth supplemented with starch or Tween 80, the cell-free culture supernatant could effectively deink and decolorize inkjetprinted paper pulp within 72 h at 30o...

  4. Engineering microbial physiology with synthetic polymers: cationic polymers induce biofilm formation in Vibrio cholerae and downregulate the expression of virulence genes.

    Science.gov (United States)

    Perez-Soto, Nicolas; Moule, Lauren; Crisan, Daniel N; Insua, Ignacio; Taylor-Smith, Leanne M; Voelz, Kerstin; Fernandez-Trillo, Francisco; Krachler, Anne Marie

    2017-08-01

    Here we report the first application of non-bactericidal synthetic polymers to modulate the physiology of a bacterial pathogen. Poly(N-[3-(dimethylamino)propyl] methacrylamide) (P1) and poly(N-(3-aminopropyl)methacrylamide) (P2), cationic polymers that bind to the surface of V. cholerae, the infectious agent causing cholera disease, can sequester the pathogen into clusters. Upon clustering, V. cholerae transitions to a sessile lifestyle, characterised by increased biofilm production and the repression of key virulence factors such as the cholera toxin (CTX). Moreover, clustering the pathogen results in the minimisation of adherence and toxicity to intestinal epithelial cells. Our results suggest that the reduction in toxicity is associated with the reduction to the number of free bacteria, but also the downregulation of toxin production. Finally we demonstrate that these polymers can reduce colonisation of zebrafish larvae upon ingestion of water contaminated with V. cholerae. Overall, our results suggest that the physiology of this pathogen can be modulated without the need to genetically manipulate the microorganism and that this modulation is an off-target effect that results from the intrinsic ability of the pathogen to sense and adapt to its environment. We believe these findings pave the way towards a better understanding of the interactions between pathogenic bacteria and polymeric materials and will underpin the development of novel antimicrobial polymers.

  5. Power plays: iron transport and energy transduction in pathogenic vibrios.

    Science.gov (United States)

    Kustusch, Ryan J; Kuehl, Carole J; Crosa, Jorge H

    2011-06-01

    The Vibrios are a unique group of bacteria inhabiting a vast array of aquatic environments. Many Vibrio species are capable of infecting a wide assortment of hosts. Some of these species include V. parahaemolyticus, V. alginolyticus, V. vulnificus, V. anguillarum, and V. cholerae. The ability of these organisms to utilize iron is essential in establishing both an infection in their hosts as well as surviving in the environment. Bacteria are able to sequester iron through the secretion of low molecular weight iron chelators termed siderophores. The iron-siderophore complexes are bound by specific outer membrane receptors and are brought through both the outer and inner membranes of the cell. The energy needed to drive this active transport is achieved through the TonB energy transduction system. When first elucidated in E. coli, the TonB system was shown to be a three protein complex consisting of TonB, ExbB and ExbD. Most Vibrio species carry two TonB systems. The second TonB system includes a fourth protein; TtpC, which is essential for TonB2 mediated iron transport. Some Vibrio species have been shown to carry a third TonB system that also includes a TtpC protein.

  6. Occurrence and Diversity of Clinically Important Vibrio Species in the Aquatic Environment of Georgia.

    Science.gov (United States)

    Kokashvili, Tamar; Whitehouse, Chris A; Tskhvediani, Ana; Grim, Christopher J; Elbakidze, Tinatin; Mitaishvili, Nino; Janelidze, Nino; Jaiani, Ekaterine; Haley, Bradd J; Lashkhi, Nino; Huq, Anwar; Colwell, Rita R; Tediashvili, Marina

    2015-01-01

    Among the more than 70 different Vibrio species inhabiting marine, estuarine, and freshwater ecosystems, 12 are recognized as human pathogens. The warm subtropical climate of the Black Sea coastal area and inland regions of Georgia likely provides a favorable environment for various Vibrio species. From 2006 to 2009, the abundance, ecology, and diversity of clinically important Vibrio species were studied in different locations in Georgia and across seasons. Over a 33-month period, 1,595 presumptive Vibrio isolates were collected from the Black Sea (n = 657) and freshwater lakes around Tbilisi (n = 938). Screening of a subset of 440 concentrated and enriched water samples by PCR-electrospray ionization/mass spectrometry (PCR-ESI/MS) detected the presence of DNA from eight clinically important Vibrio species: V. cholerae, V. parahaemolyticus, V. vulnificus, V. mimicus, V. alginolyticus, V. harveyi, V. metschnikovii, and V. cincinnatiensis. Almost 90% of PCR/ESI-MS samples positive for Vibrio species were collected from June through November. Three important human-pathogenic Vibrio species (V. cholerae, V. parahaemolyticus, and V. vulnificus) were detected in 62.8, 37.8, and 21.4% of samples testing positive for Vibrios, respectively. The results of these activities suggest that natural reservoirs for human-pathogenic Vibrios exist in Georgian aquatic environments. Water temperature at all sampling sites was positively correlated with the abundance of clinically important Vibrio spp. (except V. metschnikovii), and salinity was correlated with species composition at particular Black Sea sites as well as inland reservoirs.

  7. Saharan dust nutrients promote Vibrio bloom formation in marine surface waters

    Science.gov (United States)

    Westrich, Jason R.; Ebling, Alina M.; Landing, William M.; Joyner, Jessica L.; Kemp, Keri M.; Griffin, Dale W.; Lipp, Erin K.

    2016-01-01

    Vibrio is a ubiquitous genus of marine bacteria, typically comprising a small fraction of the total microbial community in surface waters, but capable of becoming a dominant taxon in response to poorly characterized factors. Iron (Fe), often restricted by limited bioavailability and low external supply, is an essential micronutrient that can limit Vibrio growth. Vibrio species have robust metabolic capabilities and an array of Fe-acquisition mechanisms, and are able to respond rapidly to nutrient influx, yet Vibrio response to environmental pulses of Fe remains uncharacterized. Here we examined the population growth of Vibrioafter natural and simulated pulses of atmospherically transported Saharan dust, an important and episodic source of Fe to tropical marine waters. As a model for opportunistic bacterial heterotrophs, we demonstrated that Vibrio proliferate in response to a broad range of dust-Fe additions at rapid timescales. Within 24 h of exposure, strains of Vibrio cholerae and Vibrio alginolyticus were able to directly use Saharan dust–Fe to support rapid growth. These findings were also confirmed with in situ field studies; arrival of Saharan dust in the Caribbean and subtropical Atlantic coincided with high levels of dissolved Fe, followed by up to a 30-fold increase of culturable Vibrio over background levels within 24 h. The relative abundance of Vibrio increased from ∼1 to ∼20% of the total microbial community. This study, to our knowledge, is the first to describe Vibrio response to Saharan dust nutrients, having implications at the intersection of marine ecology, Fe biogeochemistry, and both human and environmental health.

  8. [Genomic variability of vibrio cholerae El Tor biovariant strains].

    Science.gov (United States)

    Smirnova, N I; Kostromitina, E A; Osin, A V; Kutyrev, V V

    2005-01-01

    The authors performed comparative analysis of the genomes of 145 clinical and environmental isolates of Vibrio cholerae El Tor biovariants using single locus and multiplex PCR. The study found that clinical strains isolated from patients with cholera formed a genetically homogenous group, where bacterial chromosome contained all the tested virulence genes, situated on mobile genetic elements that had been acquired by the pathogen at various stages of its evolution. Strains isolated from water ecosystems during interepidemic period were heterogeneous and formed three groups: a small number of virulent strains; non-toxigenic vibrio strains that, in the process of reductional variation in their new econiche, had only managed to maintain individual virulence genes; non-pathogenic "water" vibrios, whose chromosome contained only the genes from its core part, mobile genetic elements being optionally represented only by the persistence island. Molecular typing established genetic relations among V. cholerae strains under study.

  9. Detection of Vibrio splendidus and related species in Chamelea gallina sampled in the Adriatic along the Abruzzi coastline

    Directory of Open Access Journals (Sweden)

    Marina Torresi

    2011-09-01

    Full Text Available Vibrio species are an important and widespread component of marine microbial communities. Some Vibrio strains are potentially pathogenic to marine vertebrates and invertebrates. The aim of this study was to identify vibrios, in particular Vibrio splendidus and related species, isolated from clams (Chamelea gallina collected along the coasts of the Abruzzi region from May to October 2007. The isolates obtained were phenotyped and classified as belonging to the genus Vibrio. The strains underwent biochemical testing in accordance with Alsina’s scheme for V. splendidus identification. Molecular analysis of the 16S-23S intergenic space region and recA gene was used to identify V. splendidus and related species. All the samples examined were found to contain halophylic Vibrio species, with V. alginolyticus, V. splendidus-related species and V. mediterranei most commonly found. A polymerase chain reaction of the 16S-23S intergenic space region and sequencing of the recA gene from isolates confirmed that phenotyping of Vibrio species is not sufficient to distinguish between different species. Differentiation of the highly related species among V. splendidus-related clusters remains an important issue. In this regard, our data suggests sequencing the recA genes was far more discriminatory than sequencing 16S rDNA for this purpose.

  10. Monitoring of different vibrio species affecting marine fishes in Lake Qarun and Gulf of Suez: Phenotypic and molecular characterization

    Directory of Open Access Journals (Sweden)

    Mohamed Abdelaziz

    2017-06-01

    Full Text Available Vibriosis is a globally threatening bacterial disease affecting mariculture with high mortalities and severe economic losses. Isolation and Identification of different vibrio species were performed to a total number of one hundred moribund and freshly dead Solea aegyptiaca, Epinephelus marginatus and Mugil cephalus collected from Lake Qarun and Gulf of Suez. Phenotypic picture and molecular identification based on use of 16SrRNA gene sequence confirmed 44 strains as vibrio species. Further molecular identification of retrieved vibrio spp. using species specific primers for collagenase, ToxR and Vvh genes categorized 10 isolates belong to V. alginolyticus, 8 isolates belong to V. parahaemolyticus and 6 isolates belong to V. vulnificus. The total prevalence of vibriosis was 44% where the highest prevalence was recorded in Lake Qarun examined fishes.

  11. Occurrence of Vibrio species, beta-lactam resistant Vibrio species, and indicator bacteria in ballast and port waters of a tropical harbor.

    Science.gov (United States)

    Ng, Charmaine; Goh, Shin Giek; Saeidi, Nazanin; Gerhard, William A; Gunsch, Claudia K; Gin, Karina Yew Hoong

    2018-01-01

    Ballast water discharges are potential sources for the spread of invasive and pathogenic aquatic organisms. Ballast waters from six ships docked in the Port of Singapore were tested to determine if indictor organisms fell within proposed standards for ballast water discharge according to regulation D-2 of the Ballast Water Management Convention (BWMC) guidelines. Vibrio species were cultured on media supplemented with beta-lactam antibiotics to determine the presence of antibiotic resistant Vibrio species in the ballast waters of these vessels. Indicator organisms were quantified using culture media Colilert-18 and Enterolert in ballast waters of six ships docked in a tropical harbor, with uptake from different geographical locations. Of the six ships, one had ballast water originating from the Persian Gulf, another from the East China Sea, and four from the South China Sea. Two of the six ships which carried ballast waters from the East China Sea and the South China Sea did not meet the D-2 stipulated requirements of the Ballast Water Management Convention for indicator organisms with Enterococci values more than three times higher than the acceptable limit of 110 MPN/100mL), and Vibrio parahaemolyticus (2 to >110 MPN/100mL) were detected in at least one of six ballast water samples. Using thiosulfate-citrate-bile salts-sucrose agar (TCBS) supplemented with beta-lactam antibiotics (meropenem, ceftazidime), 11 different Vibrio species, exhibiting resistance to beta-lactam antibiotics were isolated; with Vibrio campbellii (44%) and Vibrio alginolyticus (15%) the most detected antibiotic resistant Vibrio species. A practical approach of prioritized screening of high-risk vessels should be conducted to ensure that the water quality meets D-2 standards prior to discharge. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The Role of Vibrios in Diseases of Corals.

    Science.gov (United States)

    Munn, Colin B

    2015-08-01

    The tissue, skeleton, and secreted mucus of corals supports a highly dynamic and diverse community of microbes, which play a major role in the health status of corals such as the provision of essential nutrients or the metabolism of waste products. However, members of the Vibrio genus are prominent as causative agents of disease in corals. The aim of this chapter is to review our understanding of the spectrum of disease effects displayed by coral-associated vibrios, with a particular emphasis on the few species where detailed studies of pathogenicity have been conducted. The role of Vibrio shilonii in seasonal bleaching of Oculina patagonica and the development of the coral probiotic hypothesis is reviewed, pointing to unanswered questions about this phenomenon. Detailed consideration is given to studies of V. coralliilyticus and related pathogens and changes in the dominance of vibrios associated with coral bleaching. Other Vibrio-associated disease syndromes discussed include yellow band/blotch disease and tissue necrosis in temperate gorgonian corals. The review includes analysis of the role of enzymes, resistance to oxidative stress, and quorum sensing in virulence of coral-associated vibrios. The review concludes that we should probably regard most-possibly all-vibrios as "opportunistic" pathogens which, under certain environmental conditions, are capable of overwhelming the defense mechanisms of appropriate hosts, leading to rapid growth and tissue destruction.

  13. Vibrio cholerae O1 from superficial water of the Tucunduba Stream, Brazilian Amazon

    Science.gov (United States)

    Sá, L.L.C.; Vale, E.R.V.; Garza, D.R.; Vicente, A.C.P.

    2012-01-01

    Isolation and genetic characterization of an environmental Vibrio cholerae O1 from the Amazon is reported. This strain lacks two major virulence factors - CTX and TCP - but carries other genes related to virulence. Genetic similarity with epidemic strains is evaluated and the importance of V. cholerae surveillance in the Amazon is emphasized. PMID:24031874

  14. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons

    Science.gov (United States)

    Esteves, Kévin; Mosser, Thomas; Aujoulat, Fabien; Hervio-Heath, Dominique; Monfort, Patrick; Jumas-Bilak, Estelle

    2015-01-01

    Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species found in Mediterranean coastal systems can induce infections in humans. Environmental isolates of V. cholerae (n = 109) and V. parahaemolyticus (n = 89) sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA). V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST) corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus, and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity condition for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity condition. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk. PMID:26236294

  15. Amplification of tlh gene in other Vibrionaceae specie by specie-specific multiplex PCR of Vibrio parahaemolyticus

    National Research Council Canada - National Science Library

    Romina Yáñez; Roberto Bastías; Gastón Higuera; Oscar Salgado; Pantelis Katharios; Jaime Romero; Romilio Espejo; Katherine García

    2015-01-01

    Background: The surveillance of Vibrio parahaemolyticus in the Chilean coast has been mainly performed by multiplex PCR amplification of three different hemolysin genes, which are specie-specific virulence factors...

  16. Molecular Detection of the Three Major Pathogenic Vibrio Species from Seafood Products and Sediments in Tunisia Using Real-Time PCR.

    Science.gov (United States)

    Gdoura, Morsi; Sellami, Hanen; Nasfi, Hanen; Trabelsi, Rahma; Mansour, Sabeur; Attia, Touraya; Nsaibia, Siwar; Vallaeys, Tatiana; Gdoura, Radhouane; Siala, Mariam

    2016-12-01

    Vibrio spp. have emerged as a serious threat to human health worldwide. V. parahaemolyticus , V. cholerae , and V. vulnificus pose a considerable public health risk in Tunisia because they cause sporadic and epidemic foodborne infections associated with the consumption of raw or undercooked contaminated seafood. More recently, toxR-positive V. alginolyticus was also reported to be a potential source of contaminated seafood. A total of 247 samples, including 113 fishes ( Labrus viridis , Penaeus kerathurus , Diplodus annularis , Diplodus sparaillon , Scorparna porcus , Sarpa salpa , Dentex dentex , Scorparna scrofa , Sardinella aurita , Trachurus trachurus , Synodus saurus , Pagellus erythrinus , and Metapenaeus monoceros ), 83 clams ( Ruditapes decussatus species), 30 seawater samples, and 21 sediment samples were analyzed using traditional culture methods (ISO/TS 21872-1; International Organization for Standardization 2007) and a conventional PCR method for Vibrio spp. A rapid, sensitive, and highly reproducible real-time PCR assay was developed to detect the three major Vibrio spp. pathogenic for humans in Tunisian seafood products and sediments. A conventional culture method found 102 (41.3%) of 247 analyzed samples positive for Vibrio spp.; a conventional PCR method found 126 (51%) of the 247 samples positive. Real-time PCR assay found 126 (51.1%) samples positive; V. alginolyticus toxR was the most common, found in 99 (78.57%) of samples, followed by V. parahaemolyticus in 26 (20.63%) and V. cholerae in 1 (0.7%). All culture-positive samples were PCR positive. However, 24 samples that were positive by conventional PCR and real-time PCR were culture negative. Our findings indicate that retail seafood is commonly contaminated with Vibrio spp. and presents a potential risk to human health in Tunisia. These data also indicate that real-time PCR can provide sensitive species-specific detection of Vibrio spp. in seafood without prior isolation and characterization

  17. Ricerca di Vibrio splendidus e delle specie correlate in esemplari di Chamelea gallina prelevati nel tratto di mare Adriatico antistante la regione Abruzzo

    Directory of Open Access Journals (Sweden)

    Marina Torresi

    2011-09-01

    Full Text Available Le specie del genere Vibrio, ampiamente diffuse nell’ambiente marino, sono potenzialmente patogene per vertebrati e invertebrati marini. Il presente studio ha avuto l’obiettivo di identificare le specie di Vibrio, in particolare Vibrio splendidus e specie ad esso correlate, in campioni di Chamelea gallina (vongola prelevate nel tratto di mare Adriatico antistante la regione Abruzzo nel periodo Maggio-Ottobre 2007. I microrganismi isolati dai 37 campioni sono stati caratterizzati fenotipicamente e classificati come specie appartenenti al genere Vibrio. In particolare, per l’identificazione di V. splendidus sono state effettuate analisi biochimiche secondo lo schema di Alsina. Per confermare gli isolati caratterizzati biochimicamente e per identificare V. splendidus e le specie ad esso correlate sono stati utilizzati rispettivamente analisi molecolari della regione intergenica 16S-23S e sequenziamento del gene recA. Tutti i campioni sono risultati contaminati da specie di Vibrio alofile; è stata riscontrata una maggior frequenza di isolamento per V. alginolyticus, V. splendidus e specie ad esso correlate e V. mediterranei. Le analisi molecolari effettuate hanno confermato l’impossibilità di identificare tutte le specie del genere Vibrio con la caratterizzazione fenotipica. I risultati ottenuti hanno dimostrato come il sequenziamento del gene recA consenta una discriminazione maggiore rispetto a quello del 16S rDNA. L’attribuzione delle specie nel gruppo V. splendidus-related risulta tuttavia ancora controversa.

  18. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Anisia J Silva

    2016-02-01

    Full Text Available Vibrio cholerae can switch between motile and biofilm lifestyles. The last decades have been marked by a remarkable increase in our knowledge of the structure, regulation, and function of biofilms formed under laboratory conditions. Evidence has grown suggesting that V. cholerae can form biofilm-like aggregates during infection that could play a critical role in pathogenesis and disease transmission. However, the structure and regulation of biofilms formed during infection, as well as their role in intestinal colonization and virulence, remains poorly understood. Here, we review (i the evidence for biofilm formation during infection, (ii the coordinate regulation of biofilm and virulence gene expression, and (iii the host signals that favor V. cholerae transitions between alternative lifestyles during intestinal colonization, and (iv we discuss a model for the role of V. cholerae biofilms in pathogenicity.

  19. Vibrio parahaemolyticus: A Review on the Pathogenesis, Prevalence and Advance Molecular Identification Techniques

    Directory of Open Access Journals (Sweden)

    Vengadesh eLetchumanan

    2014-12-01

    Full Text Available Vibrio parahaemolyticus is a Gram-negative halophilic bacterium that is found in estuarine, marine and coastal environments. Vibrio parahaemolyticus is the leading causal agent of human acute gastroenteritis following the consumption of raw, undercooked or mishandled marine products. In rare cases, Vibrio parahaemolyticus causes wound infection, ear infection or septicaemia in individuals with pre-existing medical conditions. Vibrio parahaemolyticus has two hemolysins virulence factors that are thermostable direct hemolysin (tdh-a pore-forming protein that contributes to the invasiveness of the bacterium in humans, and TDH-related hemolysin (trh, which plays a similar role as thermostable direct hemolysin (tdh in the disease pathogenesis. In addition, the bacterium is also encodes for adhesions and type III secretion systems (T3SS1 and T3SS2 to ensure its survival in the environment. This review aims at discussing the Vibrio parahemolyticus growth and characteristics, pathogenesis, prevalence and advances in molecular identification techniques.

  20. Antiadhesive activity of poly-hydroxy butyrate biopolymer from a marine Brevibacterium casei MSI04 against shrimp pathogenic vibrios.

    Science.gov (United States)

    Kiran, George Seghal; Lipton, Anuj Nishanth; Priyadharshini, Sethu; Anitha, Kumar; Suárez, Lucia Elizabeth Cruz; Arasu, Mariadhas Valan; Choi, Ki Choon; Selvin, Joseph; Al-Dhabi, Naif Abdullah

    2014-08-13

    Vibrio pathogens are causative agents of mid-culture outbreaks, and early mortality syndrome and secondary aetiology of most dreadful viral outbreaks in shrimp aquaculture. Among the pathogenic vibrios group, Vibrio alginolyticus and V. harveyi are considered as the most significant ones in the grow-out ponds of giant black tiger shrimp Penaeus monodon in India. Use of antibiotics was banned in many countries due to the emergence of antibiotic-resistant strains and accumulation of residual antibiotics in harvested shrimp. There is an urgent need to consider the use of alternative antibiotics for the control of vibriosis in shrimp aquaculture. Biofilm formation is a pathogenic and/or establishment mechanism of Vibrio spp. This study aims to develop novel safe antibiofilm and/or antiadhesive process using PHB to contain vibrios outbreaks in shrimp aquaculture. In this study a poly-hydroxy butyrate (PHB) polymer producing bacterium Brevibacterium casei MSI04 was isolated from a marine sponge Dendrilla nigra and production of PHB was optimized under submerged-fermentation (SmF) conditions. The effect of carbon, nitrogen and mineral sources on PHB production and enhanced production of PHB by response surface methods were demonstrated. The maximum PHB accumulation obtained was 6.74 g/L in the optimized media containing 25 g/L starch as carbon source, 96 h of incubation, 35°C and 3% NaCl. The highest antiadhesive activity upto 96% was recorded against V. vulnificus, and V. fischeri, followed by 92% against V. parahaemolyticus and V. alginolyticus and 88% inhibition was recorded against V. harveyi. In this study, a thermostable biopolymer was chemically characterized as PHB based on 1HNMR spectra, FT-IR and GC-MS spectra. The NMR spectra revealed that the polymer was an isocratic homopolymer and it also confirmed that the compound was PHB. The antiadhesive activity of PHB was determined in microtitre plate assay and an effective concentration (EC) of PHB (200

  1. Comparative Genome Analyses of Vibrio anguillarum Strains Reveal a Link with Pathogenicity Traits

    DEFF Research Database (Denmark)

    Castillo, Daniel; D'Alvise, Paul; Xu, Ruiqi

    2017-01-01

    Vibrio anguillarum is a marine bacterium that can cause vibriosis in many fish and shellfish species, leading to high mortalities and economic losses in aquaculture. Although putative virulence factors have been identified, the mechanism of pathogenesis of V. anguillarum is not fully understood...... a link between genotype and virulence characteristics of Vibrio anguillarum, which can be used to unravel the molecular evolution of V. anguillarum and can also be important from survey and diagnostic perspectives. Importance : Comparative genome analysis of strains of a pathogenic bacterial species can...

  2. Efficacy of chitosan oligosaccharide as aquatic adjuvant administrated with a formalin-inactivated Vibrio anguillarum vaccine.

    Science.gov (United States)

    Liu, Xiaohong; Zhang, Hua; Gao, Yuan; Zhang, Yang; Wu, Haizhen; Zhang, Yuanxing

    2015-12-01

    Vaccine is one of the efficient candidates to prevent fish disease through activating host immune response in aquaculture. Actually, several vaccines are often administered with adjuvants to increase immunostimulation, especially for some water-based formalin-killed vaccines. However, side effects are inevitable after vaccination of some adjuvants. Therefore, exploration for effective and harmless aquatic adjuvants is urgently needed. In this study, immunoprotection of a formalin-inactivated Vibrio anguillarum vaccine applied with chitosan oligosaccharide (COS) was analyzed. High levels of protection were achieved in zebrafish and turbot vaccinated with inactivated vaccine and COS (RPS of 89.0 ± 4.5% and 80.0 ± 6.9%) compared with fish vaccinated with inactivated vaccine alone (RPS of 47.8 ± 6.6% and 64.7 ± 5.8%) at 4 week post vaccination. Moreover, high antibody reaction and cross-protection against Vibrio alginolyticus and Vibrio harveyi were observed of turbot vaccinated with inactivated vaccine and COS. In conclusion, COS can enhance immunoprotection of a formalin-inactivated V. anguillarum vaccine, significantly activate humoral immune response of host, and be benefit for inhibition against pathogens. Therefore, COS would be a potential adjuvant for aquatic vaccine design in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Impact of milk fish farming in the tropics on potentially pathogenic vibrios.

    Science.gov (United States)

    Reichardt, W T; Reyes, J M; Pueblos, M J; Lluisma, A O

    2013-12-15

    Ratios of sucrose-negative to sucrose-positive vibrios on TCBS agar (suc-/suc+) indicate the abundance of potential human pathogenic non-cholera vibrios in coastal mariculture environments of the Lingayen Gulf (Philippines. In guts of adult maricultured milkfish (Chanos chanos) of suc- vibrios reached extreme peak values ranging between 2 and 545 million per g wet weight. Suc- vibrios outnumbered suc+ vibrios in anoxic sediments, too, and were rarely predominant in coastal waters or in oxidized sediments. Suc-/suc+ ratios in sediments increased toward the mariculture areas with distance from the open sea at decreasing redox potentials. There is circumstantial evidence that suc- vibrios can be dispersed from mariculture areas to adjacent environments including coral reefs. An immediate human health risk by pathogenic Vibrio species is discounted, since milkfish guts contained mainly members of the Enterovibrio group. A representative isolate of these contained proteolytic and other virulence factors, but no genes encoding toxins characteristic of clinical Vibrio species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Genomic taxonomy of vibrios

    DEFF Research Database (Denmark)

    Thompson, Cristiane C.; Vicente, Ana Carolina P.; Souza, Rangel C.

    2009-01-01

    BACKGROUND: Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera) from 32 genome sequences of different vibrio species. We use a variety...... analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in the birth of the online genomic taxonomy whereby researchers and end-users of taxonomy will be able to identify their isolates through a web...

  5. Vibrio vulnificus infection in Southern Brazil - Case report Infecção por Vibrio vulnificus no sul do Brasil - Relato de caso

    Directory of Open Access Journals (Sweden)

    João César Beenke França

    2013-06-01

    Full Text Available The genus Vibrio is a member of the family Vibrionaceae, and among their disease-causing species, Vibrio vulnificus, a lactose-positive gram-negative bacillus, is one of the most virulent pathogen of the noncholerae vibrios. We describe the case of a 39-year-old male patient, who was using immunosuppressive therapy, admitted to the hospital for liver transplantation. Twelve hours later, the patient presented high fever, myalgia, anuria and erythematous plaques on lower limbs, of rapid growth and proximal progression. The patient was treated with ceftriaxone, meropenem and oxacillin, however he expired within 30 hours. Blood cultures showed growth of a gram-negative bacillus, which was later identified as Vibrio vulnificus.O gênero Vibrio é membro da família Vibrionaceae, e entre as espécies patogênicas, Vibrio vulnificus, bacilo gram negativo lactose positivo, tem sido frequentemente citado. Descrevemos o caso de um paciente masculino de 39 anos, em uso de medicação imunossupressora, admitido no hospital para transplante hepático. Doze horas após a internação, o paciente evoluiu com febre, mialgias, anúria e placas eritematosas em membros inferiores, com rápido crescimento e evolução proximal. O paciente foi tratado com ceftriaxona, meropenem e oxacilina sem melhora, evoluindo para óbito em 30 horas. Hemocultura mostrou crescimento de bacilo gram negativo posteriormente identificado como Vibrio vulnificus.

  6. [Detection of Salmonella, Listeria spp., Vibrio spp., and Yersinia enterocolitica in frozen seafood and comparison with enumeration for faecal indicators: implication for public health].

    Science.gov (United States)

    Ripabelli, G; Sammarco, M L; Fanelli, I; Grasso, G M

    2004-01-01

    Infections transmitted through consumption of contaminated seafood is a significant source of human morbidity. The aim of this study was to compare the detection of Salmonella, Listeria, Vibrio, and Yersinia enterocolitica in frozen seafood with results from enumeration of conventional faecal indicators. A total of 213 crustaceans or molluscs were purchased from local vendors in Italy: 74% were harvested in Italy, 25% from other European countries and 1% from outside Europe. Listeria spp. was isolated from 20% of samples, Vibrio spp. from 11%, Salmonella from 3% and Y. enterocolitica from 1%. Listeria species isolated were L. monocytogenes, L. innocua, L. welshimeri, L. ivanovii and L. seeligeri. Vibrio species isolated were V. alginolyticus and V. fluvialis. The most contaminated shellfish for both faecal indicator microrganism and pathogens were hen clams (6% contained Salmonella, 27% Listeria spp. and 3% Y. enterocolitica), while from 27% of shrimps Vibrio spp. was recovered. Higher levels of faecal indicators were recovered from samples harvested outside Europe, and 66% of samples harvested in Thailand were contaminated from Salmonella. Significant differences were found in the levels of contamination of seafoods depending upon the freezing regime, but there was a limited association between presence of potential pathogens (particularly Vibrio spp.) and conventional faecal indicators. Hence, we suggest reconsideration of current legal parameters to evaluate microbiological quality of seafood.

  7. Characterization of a new beta-lactamase gene from isolates of Vibrio spp. in Korea.

    Science.gov (United States)

    Jun, Lyu Jin; Kim, Jae Hoon; Jin, Ji Woong; Jeong, Hyun Do

    2012-04-01

    PCR was performed to analyze the beta-lactamase genes carried by ampicillin-resistant Vibrio spp. strains isolated from marine environments in Korea between 2006 and 2009. All 36 strains tested showed negative results in PCR with the primers designed from the nucleotide sequences of various known beta-lactamase genes. This prompted us to screen new beta-lactamase genes. A novel beta-lactamase gene was cloned from Vibrio alginolyticus KV3 isolated from the aquaculture water of Geoje Island of Korea. The determined nucleotide sequence (VAK-3 beta-lactamase) revealed an open reading frame (ORF) of 852 bp, encoding a protein of 283 amino acids (aa), which displayed low homology to any other beta-lactamase genes reported in public databases. The deduced 283 aa sequence of VAK-3, consisting of a 19 aa signal peptide and a 264 aa mature protein, contained highly conserved peptide segments specific to class A beta-lactamases including the specific amino acid residues STFK (62-65), SDN (122-124), E (158), and RTG (226-228). Results from PCR performed with primers specific to the VAK-3 beta-lactamase gene identified 3 of the 36 isolated strains as V. alginolyticus, Vibrio cholerae, and Photobacterium damselae subsp. damselae, indicating the utilization of various beta-lactamase genes including unidentified ones in ampicillin-resistant Vibrio spp. strains from the marine environment. In a mating experiment, none of the isolates transfered the VAK-3 beta-lactamase gene to the Escherichia coli recipient. This lack of mobility, and the presence of a chromosomal acyl-CoA flanking sequence upstream of the VAK-3 beta- lactamase gene, led to the assumption that the location of this new beta-lactamase gene was in the chromosome, rather than the mobile plasmid. Antibiotic susceptibility of VAK-3 beta-lactamase was indicated by elevated levels of resistance to penicillins, but not to cephalosporins in the wild type and E. coli harboring recombinant plasmid pKV-3, compared with those of

  8. Role of iron, capsule, and toxins in the pathogenicity of Vibrio vulnificus biotype 2 for mice.

    OpenAIRE

    Amaro, C; Biosca, E G; Fouz, B; Toranzo, A E; Garay, E

    1994-01-01

    The virulence mechanisms of Vibrio vulnificus biotype 2 have been studied and compared with those of biotype 1 in mice as the experimental animals. Biotype 2 isolates from European eels were as virulent for mice as biotype 1 strains (50% lethal dose, about 10(5) CFU per mouse); a septicemic infection developed in less than 24 h. These strains had several properties in common with biotype 1 organisms including capsule expression, uptake of various iron sources, and production of exoproteins, w...

  9. Characterization of the secretomes of two vibrios pathogenic to mollusks.

    Science.gov (United States)

    Madec, Stéphanie; Pichereau, Vianney; Jacq, Annick; Paillard, Mathieu; Boisset, Claire; Guérard, Fabienne; Paillard, Christine; Nicolas, Jean-Louis

    2014-01-01

    Vibrio tapetis causes the brown ring disease in the Japanese clam Ruditapes philippinarum while Vibrio aestuarianus is associated with massive oyster mortalities. As extracellular proteins are often associated with the virulence of pathogenic bacteria, we undertook a proteomic approach to characterize the secretomes of both vibrios. The extracellular proteins (ECPs) of both species were fractionated by SEC-FPLC and in vitro assays were performed to measure the effects of each fraction on hemocyte cellular parameters (phagocytosis and adhesion). Fractions showing a significant effect were subjected to SDS-PAGE, and proteins were identified by nano LC-MS/MS. 45 proteins were identified for V. aestuarianus and 87 for V. tapetis. Most of them belonged to outer membrane or were periplasmic, including porins or adhesins that were already described as virulence factors in other bacterial species. Others were transporter components, flagella proteins, or proteins of unknown function (14 and 15 respectively). Interestingly, for V. aestuarianus, we noted the secretion of 3 extracellular enzymes including the Vam metalloprotease and two other enzymes (one putative lipase and one protease). For V. tapetis, we identified five extracellular enymes, i.e. two different endochitinases, one protease, one lipase and an adhesin. A comparison of both secretomes also showed that only the putative extracellular lipase was common to both secretomes, underscoring the difference in pathogenicity mechanisms between these two species. Overall, these results characterize for the first time the secretomes of these two marine pathogenic vibrios and constitute a useful working basis to further analyze the contribution of specific proteins in the virulence mechanisms of these species.

  10. Vibrio Parahaemolyticus: The Threat of Another Vibrio Acquiring Pandemic Potential

    Digital Repository Service at National Institute of Oceanography (India)

    Ramamurthy, T.; Nair, G.B.

    or indirectly via contaminated food and water. Food-borne Vibrio infections tend to occur more frequently in developed countries while transmission of Vibrio infections in developing countries is, by and large, water-borne. Further, the magnitude of food... and pandemics mainly due to poor water supply and personal hygiene. The other important and most common seafood-borne halophilic Vibrio is V. parahaemolyticus. Since its discovery in 1953 (Fujino et al., 1953), many aspects on this pathogen were explored...

  11. Molecular Analysis and Toxigenic Potential of Vibrio cholerae Isolated from Hilsha fish (Tenualosa ilisha), Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Farhana, Israt; Tulsiani, Suhella

    Exposure to contaminated fish may upsurge the virulent strains of Vibrio cholerae, the deadly human pathogen in the households of rural and urban Bangladesh. Since V. cholerae spreading was reported from the Bay of Bengal, this study hypothesized that Hilsha (Tenualosa ilisha), a marine and fresh...

  12. An acute gastroenteritis outbreak of Vibrio parahaemolyticus O4:K55 in Nursing College, Thailand.

    Science.gov (United States)

    Jatapai, A; Moungthong, B; Thunyaharn, S; Huttayananont, S; Rangsin, R

    2010-08-01

    A cluster of acute gastroenteritis among nursing students was noticed on 13th September 2005. Between 13th and 17th September 2005, a retrospective cohort study was then conducted to identify the most likely cause of gastroenteritis at a nursing college in Bangkok, Thailand. Self-administered questionnaires, interviews, environmental investigations, and rectal swabs from all participants were carried out. In the investigation, 98.9% female nursing students were investigated and had completed the questionnaire, 49.4% of the participants were diagnosed to have acute gastroenteritis. The predominant symptoms were watery diarrhoea (90.8%) and abdominal cramps (71.3%). Of 28.9% of rectal swab isolates were identified as Vibrio parahaemolyticus O4:K55 (40.4%), Salmonella spp. (19.2%), Vibrio cholerae non O1/non O139/non O141 (11.5%), Aeromonas trota (3.9%), Vibrio alginolyticus (1.9%) and other co-infections (23.1%). The tdh gene was identified from all V. parahaemolyticus using multiplex PCR. The implicated food risk factor for gastroenteritis was boiled egg (adjusted prevalence rate ratio; PR=1.9, 95% CI, 1.04-3.79). However the bitter melon soup was not significantly associated for gastroenteritis (adjusted PR=1.3, 95% CI, 0.98-1.82). The population attributable fraction analysis indicated that boiled eggs item was an implicated food risk for this outbreak (PAF=45.8%). Vibrio parahaemolyticus O4:K55 was identified as a major causative agent for gastroenteritis in which the contaminated boiled eggs was a vehicle in this outbreak. Cross-contamination control should be emphasized in food operation plans among institutes.

  13. Persistence, seasonal dynamics and pathogenic potential of Vibrio communities from Pacific oyster hemolymph.

    Science.gov (United States)

    Wendling, Carolin C; Batista, Frederico M; Wegner, K Mathias

    2014-01-01

    Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods.

  14. Isolation and characterization of agar-digesting Vibrio species from the rotten thallus of Gracilariopsis heteroclada Zhang et Xia.

    Science.gov (United States)

    Martinez, Joval N; Padilla, Philip Ian P

    2016-08-01

    Gracilariopsis heteroclada Zhang et Xia (Gracilariaceae, Rhodophyta) is one of the most studied marine seaweeds due to its economic importance. This has been cultivated extensively on commercial scale in the Philippines and other Asian countries. However, sustainable production of G. heteroclada in the Philippines could not be maximized due to the occurrence of rotten thallus disease. Thus, isolation and characterization of agar-digesting bacteria from the rotten thalli of G. heteroclada was conducted. A total of seven representative bacterial isolates were randomly selected based on their ability to digest agar as evidenced by the formation of depressions around the bacterial colonies on nutrient agar plates supplemented with 1.5% NaCl and liquefaction of agar. Gram-staining and biochemical characterization revealed that isolates tested were gram-negative rods and taxonomically identified as Vibrio parahaemolyticus (86-99.5%) and Vibrio alginolyticus (94.2-97.7%), respectively. It is yet to be confirmed whether these agar-digesting vibrios are involved in the induction and development of rotten thallus disease in G. heteroclada in concomitance with other opportunistic bacterial pathogens coupled with adverse environmental conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A single regulatory gene is sufficient to alter Vibrio aestuarianus pathogenicity in oysters.

    Science.gov (United States)

    Goudenège, David; Travers, Marie Agnès; Lemire, Astrid; Petton, Bruno; Haffner, Philippe; Labreuche, Yannick; Tourbiez, Delphine; Mangenot, Sophie; Calteau, Alexandra; Mazel, Didier; Nicolas, Jean Louis; Jacq, Annick; Le roux, Frédérique

    2015-11-01

    Oyster diseases caused by pathogenic vibrios pose a major challenge to the sustainability of oyster farming. In France, since 2012 a disease affecting specifically adult oysters has been associated with the presence of Vibrio aestuarianus. Here, by combining genome comparison, phylogenetic analyses and high-throughput infections of strains isolated before or during the recent outbreaks, we show that virulent strains cluster into two V. aestuarianus lineages independently of the sampling dates. The bacterial lethal dose was not different between strains isolated before or after 2012. Hence, the emergence of a new highly virulent clonal strain is unlikely. Each lineage comprises nearly identical strains, the majority of them being virulent, suggesting that within these phylogenetically coherent virulent lineages a few strains have lost their pathogenicity. Comparative genomics allowed the identification of a single frameshift in a non-virulent strain. This mutation affects the varS gene that codes for a signal transduction histidine-protein kinase. Genetic analyses confirmed that varS is necessary for infection of oysters and for a secreted metalloprotease expression. For the first time in a Vibrio species, we show here that VarS is a key factor of pathogenicity. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Determinación de la frecuencia de Vibrio parahaemolyticus y otros vibriones halofilicos en alimentos preparados con productos marinos frescos y procesados

    Directory of Open Access Journals (Sweden)

    Amabilia Vilcapoma

    2014-06-01

    Full Text Available El trabajo se realizó durante las estaciones de verano a otoño de 1988, sobre un total de 122 muestras, correspondiendo 82 a pescado congelado y 40 a cebiches, en su mayoría de tipo "mixto"; todos procedentes de la ciudad de Lima. El procesamiento de las muestras y el aislamiento de los vibrio se efectuaron siguiendo la metodología recomendada por la FDA (1985, con algunas modificaciones. La identificación de las cepas se realizó en base a caracteristicas de colonia, morfología celular y pruebas bioquímicas diferenciales. Se obtuvieron 57 cepas presuntivas de vibriones halofílicos, de las cuales 42 procedieron de pescado congelado y 15 de "cebiches"; se identificaron 5 cepas de Vibrio parahaemoIyticus (8.8% y 14 cepas de Vibrio alginolyticus (24.6% 38 cepas de Vibrio no fueron especificados, catalogándose como Vlbrio sp. (66.6%.

  17. Vibrio spp. isolados a partir de mexilhões (Perna perna in natura e pré-cozidos de Estação Experimental de Cultivo, Rio de Janeiro, RJ, Brasil Vibrio spp. isolated from in natura and precooked mussels (Perna perna of an Experimental Station Culture, Rio de Janeiro, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Christiane Soares Pereira

    2007-06-01

    Full Text Available A análise microbiológica dos mexilhões reflete a qualidade do habitat aquático, pois estes animais podem reter em seus organismos diversos patógenos, dentre os quais aqueles pertencentes à família Vibrionaceae. No presente estudo foi avaliada a presença de Vibrio spp. em mexilhões (in natura e pré-cozidos, comercializados na Estação Experimental de Cultivo de Mexilhões, situada em Jurujuba, Niterói, Rio de Janeiro. Foram avaliadas 86 amostras, tomando como procedimento, o enriquecimento em Água Peptonada Alcalina (APA adicionada de 1 e 3% de NaCl, isolamento em Agar Tiossulfato Citrato Bile Sacarose (TCBS e confirmação das colônias típicas por análise bioquímica. Dentre as 12 espécies de Vibrio identificadas destacaram-se como de maior prevalência as espécies Vibrio alginolyticus, V. cholerae não-O1, V. parahaemolyticus, V. carchariae e Vibrio vulnificus. A relevância epidemiológica destes patógenos associada a casos de gastrenterite humana após consumo de mexilhões crus ou parcialmente cozidos, reforça a importância de alertar as autoridades de Vigilância Sanitária sobre sua presença na cadeia alimentar e seus riscos para a Saúde Pública.The microbiology analysis of mussels reflects the aquatic environment quality because these animals retain various pathogens such as Vibrionaceae family microorganisms in their organism. In the present investigation, we evaluated the presence of Vibrio spp. in mussels (in natura and precooked commercialized at an Experimental Station Mussel Culture in Jurujuba, Niterói, Rio de Janeiro. A total of 86 samples were analyzed using the enrichment in Alkaline Peptone Water (APW added to 1 and 3% of NaCl, isolated in Thiossulfate Citrate Bile Sucrose Agar (TCBS and confirmed that there were suspect colonies by biochemical tests. The results showed the identification of 12 different Vibrio species whereby Vibrio alginolyticus, V. cholerae non-O1, V. parahaemolyticus, V. carchariae

  18. Impact of Hurricane Irene on Vibrio vulnificus and Vibrio parahaemolyticus concentrations in surface water, sediment, and cultured oysters in the Chesapeake Bay, MD, USA.

    Science.gov (United States)

    Shaw, Kristi S; Jacobs, John M; Crump, Byron C

    2014-01-01

    To determine if a storm event (i.e., high winds, large volumes of precipitation) could alter concentrations of Vibrio vulnificus and V. parahaemolyticus in aquacultured oysters (Crassostrea virginica) and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface (0.3 m) and near-bottom (just above the sediment). Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number (MPN) enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration for either Vibrio species by location (surface or near bottom oysters) or date sampled (oyster tissue, surface water, and sediment concentrations). V. vulnificus in oyster tissue was correlated with total suspended solids (r = 0.41, P = 0.04), and V. vulnificus in sediment was correlated with secchi depth (r = -0.93, P depth [r = -0.48, P = 0.02 (sediment); r = -0.97, P <0.01 (surface water)] and tidal height [r = -0.96, P <0.01 (sediment), r = -0.59, P <0.01 (surface water)]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4 × 10(5) MPN g(-1), V. parahaemolyticus 1 × 10(5) MPN g(-1)), and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment, and surface water at an aquaculture facility in the Chesapeake Bay.

  19. Role of Vibrio polysaccharide (vps) genes in VPS production, biofilm formation and Vibrio cholerae pathogenesis.

    Science.gov (United States)

    Fong, Jiunn C N; Syed, Khalid A; Klose, Karl E; Yildiz, Fitnat H

    2010-09-01

    Biofilm formation enhances the survival and persistence of the facultative human pathogen Vibrio cholerae in natural ecosystems and its transmission during seasonal cholera outbreaks. A major component of the V. cholerae biofilm matrix is the Vibrio polysaccharide (VPS), which is essential for development of three-dimensional biofilm structures. The vps genes are clustered in two regions, the vps-I cluster (vpsU, vpsA-K, VC0916-27) and the vps-II cluster (vpsL-Q, VC0934-39), separated by an intergenic region containing the rbm gene cluster that encodes biofilm matrix proteins. In-frame deletions of the vps clusters and genes encoding matrix proteins drastically altered biofilm formation phenotypes. To determine which genes within the vps gene clusters are required for biofilm formation and VPS synthesis, we generated in-frame deletion mutants for all the vps genes. Many of these mutants exhibited reduced capacity to produce VPS and biofilms. Infant mouse colonization assays revealed that mutants lacking either vps clusters or rbmA (encoding secreted matrix protein RbmA) exhibited a defect in intestinal colonization compared to the wild-type. Understanding the roles of the various vps gene products will aid in the biochemical characterization of the VPS biosynthetic pathway and elucidate how vps gene products contribute to VPS biosynthesis, biofilm formation and virulence in V. cholerae.

  20. Autecology of Vibrio vulnificus and Vibrio parahaemolyticus in tropical waters

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, S.; Lugo, T.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

    1988-12-31

    Water and shellfish samples collected from estuaries, mangroves, and beaches along the coast of Puerto Rico were examined for Vibrio vulnificus and Vibrio parahaemolyticus. An array of water quality parameters were also measured simultaneous with bacteria sampling. Both species of vibrio were associated with estuary and mangrove locations, and neither was isolated from sandy beaches. Densities of V. vulnificus were negatively correlated with salinity, 10--15 ppt being optimal. V. parahaemolyticus was isolated from sites with salinities between 20 and 35 ppt, the highest densities occurring at 20 ppt. Densities of Vibrio spp. and V. parahaemolyticus for a tropical estuary surpassed those reported for temperate estuaries by several orders of magnitude. Both densities of total Vibrio spp. and V. parahaemolyticus in the water were directly related to densities of fecal coliforms, unlike V. vulnificus. The incidence of ONPG(+) strains among sucrose({minus}) Vibrio spp. served as an indicator of the frequency of V. vulnificus in this group. More than 63% of the V. vulnificus isolated were pathogenic. V. vulnificus and V. parahaemolyticus occupy clearly separate niches within the tropical estuarine-marine ecosystem.

  1. Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae

    Science.gov (United States)

    Defoirdt, Tom; Sorgeloos, Patrick

    2012-01-01

    Quorum sensing, bacterial cell-to-cell communication, has been linked to the virulence of pathogenic bacteria. Indeed, in vitro experiments have shown that many bacterial pathogens regulate the expression of virulence genes by this cell-to-cell communication process. Moreover, signal molecules have been detected in samples retrieved from infected hosts and quorum sensing disruption has been reported to result in reduced virulence in different host–pathogen systems. However, data on in vivo quorum sensing activity of pathogens during infection of a host are currently lacking. We previously reported that quorum sensing regulates the virulence of Vibrio harveyi in a standardised model system with gnotobiotic brine shrimp (Artemia franciscana) larvae. Here, we monitored quorum sensing activity in Vibrio harveyi during infection of the shrimp, using bioluminescence as a read-out. We found that wild-type Vibrio harveyi shows a strong increase in quorum sensing activity early during infection. In this respect, the bacteria behave remarkably similar in different larvae, despite the fact that only half of them survive the infection. Interestingly, when expressed per bacterial cell, Vibrio harveyi showed around 200-fold higher maximal quorum sensing-regulated bioluminescence when associated with larvae than in the culture water. Finally, the in vivo quorum sensing activity of mutants defective in the production of one of the three signal molecules is consistent with their virulence, with no detectable in vivo quorum sensing activity in AI-2- and CAI-1-deficient mutants. These results indicate that AI-2 and CAI-1 are the dominant signals during infection of brine shrimp. PMID:22673627

  2. Production of acylated homoserine lactones by different serotypes of Vibrio anguillarum both in culture and during infection of rainbow trout

    DEFF Research Database (Denmark)

    Buch, Christiane; Sigh, Jens; Nielsen, John

    2003-01-01

    Onehundred and forty-eight out of onehundred and fifty strains of Vibrio anguillarum isolated from vibriosis in Danish marine aquaculture produced bacterial communication signals, acylated homoserine lactones, eliciting a response in the Agrobacterium tumefaciens (pZLR4) monitoring system. One....... anguillarum strains and that no clear pattern relating AHL production to disease or virulence appear....

  3. Genome analysis of the coral bleaching pathogen Vibrio shiloi.

    Science.gov (United States)

    Reshef, Leah; Ron, Eliora; Rosenberg, Eugene

    2008-08-01

    The past few decades have seen a world-wide increase in coral diseases, yet little is known about coral pathogens. In this study, techniques commonly used in pathogenomic research were applied to the coral pathogen Vibrio shiloi in order to identify genetic elements involved in its virulence. Suppressive subtractive hybridization was used to compare the gene content of V. shiloi to that of a closely related but non-pathogenic bacterium, Vibrio mediterranei, resulting in identification of several putative virulence factors and of three novel genomic islands. The entire genome of V. shiloi was further screened for genes related to previously characterized steps in infection: adhesion, superoxide dismutase production and toxin production. Exposure of pure cultures of V. shiloi to crushed coral tissues strongly affected the expression of seven genes encoding pili, zona occludins toxin (Zot) and a superoxide dismutase. Analysis of eight V. shiloi strains isolated in the last decade shows a shift of the natural population from strains carrying all three genomic islands to strains carrying none of them. This shift occurred following appearance of resistance in the coral Oculina patagonica to infection by V. shiloi. The relevance of these findings to the bleaching disease caused by V. shiloi is discussed.

  4. Characterization of clinical Vibrio parahaemolyticus strains in Zhoushan, China, from 2013 to 2014.

    Directory of Open Access Journals (Sweden)

    Hongling Wang

    Full Text Available Vibrio parahaemolyticus is recognized as major cause of foodborne illness of global public health concern. This study collected 107 strains of V. parahaemolyticus during active surveillance of diarrheal diseases in hospitals in Zhoushan during 2013 to 2014 and investigated their serotypes, virulence genes (tdh, trh, and orf8, antimicrobial resistance, and genotypes. The dominant serotypes of the 107 clinical strains were O3:K6, O4:K8, and O4:KUT with 87.9% and 3.7% of the strains carrying the virulence genes tdh and trh, respectively. Molecular typing by pulsed-field gel electrophoresis indicated divergence among the clinical strains. Most isolates were sensitive to the common antimicrobial agents used against the Vibrio species except ampicillin. We conclude that continuous surveillance of V. parahaemolyticus in diarrhea patients is a public health priority and is useful for conducting risk assessment of foodborne illnesses caused by V. parahaemolyticus.

  5. The pathogenesis, detection and prevention of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Rongzhi eWang

    2015-03-01

    Full Text Available Vibrio parahaemolyticus, a Gram-negative motile bacterium that inhabits marine and estuarine environments throughout the world, is a major food-borne pathogen that causes life-threatening diseases in humans after the consumption of raw or undercooked seafood. The global occurrence of V. parahaemaolyticus accentuates the importance of investigating its virulence factors and their effects on the human host. This review describes the virulence factors of V. parahaemolyticus reported to date, including hemolysin, urease, two type III secretion systems (T3SS and two type VI secretion systems (T6SS, which both cause both cytotoxicity in cultured cells and enterotoxicity in animal models. We describe various types of detection methods, based on virulence factors, that are used for quantitative detection of V. parahaemolyticus in seafood. We also discuss some useful preventive measures and therapeutic strategies for the diseases mediated by V. parahaemolyticus, which can reduce, to some extent, the damage to humans and aquatic animals attributable to V. parahaemolyticus. This review extends our understanding of the pathogenic mechanisms of V. parahaemolyticus mediated by virulence factors and the diseases it causes in its human host. It should provide new insights for the diagnosis, treatment, and prevention of V. parahaemolyticus infection.

  6. Identification of DNA Sequences Specific for Vibrio vulnificus Biotype 2 Strains by Suppression Subtractive Hybridization

    OpenAIRE

    Lee, Chung-Te; Amaro, Carmen; Sanjuán, Eva; Hor, Lien-I

    2005-01-01

    Vibrio vulnificus can be divided into three biotypes, and only biotype 2, which is further divided into serovars, contains eel-virulent strains. We compared the genomic DNA of a biotype 2 serovar E isolate (tester) with the genomic DNAs of three biotype 1 strains by suppression subtractive hybridization and then tested the distribution of the tester-specific DNA sequences in a wide collection of bacterial strains. In this way we identified three plasmid-borne DNA sequences that were specific ...

  7. Characterization of the Hemorrhagic Reaction Caused by Vibrio vulnificus Metalloprotease, a Member of the Thermolysin Family

    OpenAIRE

    Miyoshi, Shin-ichi; Nakazawa, Hiromi; Kawata, Koji; Tomochika, Ken-ichi; Tobe, Kazuo; Shinoda, Sumio

    1998-01-01

    Vibrio vulnificus is an opportunistic human pathogen causing wound infections and septicemia, characterized by hemorrhagic and edematous damage to the skin. This human pathogen secretes a metalloprotease (V. vulnificus protease [VVP]) as an important virulence determinant. When several bacterial metalloproteases including VVP were injected intradermally into dorsal skin, VVP showed the greatest hemorrhagic activity. The level of the in vivo hemorrhagic activity of the bacterial metalloproteas...

  8. Genome-wide characterization of vibrio phage ϕpp2 with unique arrangements of the mob-like genes

    Directory of Open Access Journals (Sweden)

    Lin Ying-Rong

    2012-06-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is associated with gastroenteritis, wound infections, and septicemia in human and animals. Phages can control the population of the pathogen. So far, the only one reported genome among giant vibriophages is KVP40: 244,835 bp with 26% coding regions that have T4 homologs. Putative homing endonucleases (HE were found in Vibrio phage KVP40 bearing one segD and Vibrio cholerae phage ICP1 carrying one mobC/E and one segG. Results A newly isolated Vibrio phage ϕpp2, which was specific to the hosts of V. parahaemolyticus and V. alginolyticus, featured a long nonenveloped head of ~90 × 150 nm and tail of ~110 nm. The phage can survive at 50°C for more than one hour. The genome of the phage ϕpp2 was sequenced to be 246,421 bp, which is 1587 bp larger than KVP40. 383 protein-encoding genes (PEGs and 30 tRNAs were found in the phage ϕpp2. Between the genomes of ϕpp2 and KVP40, 254 genes including 29 PEGs for viral structure were of high similarity, whereas 17 PEGs of KVP40 and 21 PEGs of ϕpp2 were unmatched. In both genomes, the capsid and tail genes have been identified, as well as the extensive representation of the DNA replication, recombination, and repair enzymes. In addition to the three giant indels of 1098, 1143 and 3330 nt, ϕpp2 possessed unique proteins involved in potassium channel, gp2 (DNA end protector, tRNA nucleotidyltransferase, and mob-type HEs, which were not reported in KVP40. The ϕpp2 PEG274, with strong promoters and translational initiation, was identified to be a mobE type, flanked by NrdA and NrdB/C homologs. Coincidently, several pairs of HE-flanking homologs with empty center were found in the phages of Vibrio phages ϕpp2 and KVP40, as well as in Aeromonas phages (Aeh1 and Ae65, and cyanophage P-SSM2. Conclusions Vibrio phage ϕpp2 was characterized by morphology, growth, and genomics with three giant indels and different types of HEs. The gene analysis on the required

  9. Vibrio parahaemolyticus- An emerging foodborne pathogen

    Directory of Open Access Journals (Sweden)

    S Nelapati

    2012-02-01

    Full Text Available Vibrio parahaemolyticus is a halophilic gram negative, motile, oxidase positive, straight or curved rod-shaped, facultative anaerobic bacteria that occur naturally in the marine environment. They form part of the indigenous microflora of aquatic habitats of various salinity and are the major causative agents for some of the most serious diseases in fish, shellfish and penacid shrimp. This human pathogen causes acute gastroenteritis characterized by diarrhea, vomiting and abdominal cramps through consumption of contaminated raw fish or shellfish. V. parahaemolyticus is the leading cause of gastroenteritis due to the consumption of seafood worldwide. The incidence of V. parahaemolyticus infection has been increasing in many parts of the world, due to the emergence of O3:K6 serotype carrying the tdh gene which is responsible for most outbreaks worldwide. The pathogenicity of this organism is closely correlated with the Kanagawa phenomenon (KP + due to production of Kanagawa hemolysin or the thermostable direct hemolysin (TDH. The TDH and TRH (TDH-related hemolysin encoded by tdh and trh genes are considered to be important virulence factors. [Vet. World 2012; 5(1.000: 48-63

  10. Impact of Hurricane Irene on Vibrio vulnificus and Vibrio parahaemolyticus concentrations in surface water, sediment and cultured oysters in the Chesapeake Bay, Maryland, USA

    Directory of Open Access Journals (Sweden)

    Kristi S Shaw

    2014-05-01

    Full Text Available To determine if a storm event (i.e., high winds, large volumes of precipitation could alter concentrations of Vibrio vulnificus and Vibrio parahaemolyticus in aquacultured oysters (Crassostrea virginica and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface 0.3 m and near-bottom just above the sediment. Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration change for either Vibrio species by location (surface or near bottom oysters or date sampled (oyster tissue, surface water and sediment concentrations. V. vulnificus in oyster tissue was correlated with total suspended solids (r=0.41, p=0.04, and V. vulnificus in sediment was correlated with secchi depth (r=-0.93, p< 0.01, salinity (r=-0.46, p=0.02, tidal height (r=-0.45, p=0.03, and surface water V. vulnificus (r=0.98, p< 0.01. V. parahaemolyticus in oyster tissue did not correlate with environmental measurements, but V. parahaemolyticus in sediment and surface water correlated with several measurements including secchi depth (r=-0.48, p=0.02[sediment]; r=-0.97 p< 0.01[surface water] and tidal height (r=-0.96. p< 0.01[sediment], r=-0.59,p< 0.01 [surface water]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4x105 MPN g-1, V. parahaemolyticus 1x105 MPN g-1, and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment and

  11. Zoonose Vibrio vulnificus: meldingsplicht raadzaam

    NARCIS (Netherlands)

    Dijkstra, A.; Haenen, O.L.M.; Moller, L.

    2010-01-01

    Op de lijst van meldingsplichtige infectieziekten komen een aantal zoönosen voor, zoals pest, rabiës en leptospirose. De relatief onbekende zoönotische Vibrio vulnificus valt opmerkelijk genoeg niet onder de meldingsplichtige infectieziekten. Juist vanwege het zeer agressieve beloop van een

  12. Prevalence of Vibrio vulnificus and Vibrio parahaemolyticus in the Maryland Coastal Bays

    Science.gov (United States)

    De Pascuale, V. O.

    2016-02-01

    The bacterial family of Vibrionaceae is indigenous in the marine estuarine environments such as the Maryland Coastal Bays. Vibrio vulnificus and Vibrio parahaemolyticus are both pathogenic bacteria. Understanding the distribution of Vibrio species is crucial because of the health concerns associated with the bacteria. The aim of this study was to evaluate the overall abundance of bacteria with a focus on Vibrio species in the Maryland Coastal Bays. Seawater samples were collected from 10 different sites that differ with regard to water quality. The total bacteria count (TBC) was determined by two methods: Total plate count and Epifluorescence microscopy. The most-probable-number (MPN) methodology was used to estimate the population of Vibrio parahaemolyticus and Vibrio vulnificus. In addition to the bacteriological analysis, the environmental parameters of temperature and salinity were measured using YSI 6600 multiparameter meter. The average total bacteria count was 2.21 log CFU ml-1. Vibrio vulnificus comprised 5% of the total bacteria count while Vibrio parahaemolyticus comprised only 2% of the total bacteria count. Vibrio vulnificus ranged from 0.30 to 2.48 log MPN ml-1 at the sites tested. Lower Vibrio parahaemolyticus count was observed at the sites with a range of 0.30 to 1.97 log MPN ml-1. There was no significant correlation between the environmental parameters and the Vibrio spp. Since both Vibrio vulnificus and Vibrio parahaemolyticus peak in the summer, there is a potential for a risk of wound infections and gastrointestinal illness based on this data.

  13. Virulence Attributes of Low-Virulence Organisms

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    Bryan Larsen

    1994-01-01

    virulence organisms present in the female lower genital tract, we are beginning to identify some of their virulence attributes. Examples from the work of our laboratory include the hemolysin of Gardnerella vaginalis and an immunosuppressive mycotoxin produced by Candida albicans. Demonstrating the coordinate expression (or other control mechanisms of virulence factors in these sometimes innocuous and sometimes inimical organisms represents the next frontier in the study of normal vaginal microbiology.

  14. FURTHER STUDIES ON THE ETIOLOGICAL ROLE OF VIBRIO FETUS.

    Science.gov (United States)

    Smith, T; Little, R B; Taylor, M S

    1920-11-30

    subject to modification with increasing knowledge of this type of infectious abortion. The infectious agent was probably introduced by purchased cows in 1917 or earlier. It gained a certain headway up to 1919, then the number of cases declined so that between May, 1919, and May, 1920, only the above three cases in heifers, and one case of mixed infection with Bacillus abortus in an older cow, were detected. During the same period cases due to Bacillus abortus continued undiminished. The greater resistance of Bacillus abortus manifested in cultures as compared with Vibrio fetus is thus reflected in its behavior in nature. The temporary dying out of the infection indicates that natural immunization of a herd to Vibrio fetus proceeds quite rapidly. Another outbreak may be expected when the immunity of the herd has declined in the absence of the infecting agent and the latter is reintroduced from without, or it may reappear at any time when a vibrio of higher virulence is brought in.

  15. The Vibrio cholerae cytolysin promotes chloride secretion from intact human intestinal mucosa.

    Directory of Open Access Journals (Sweden)

    Lucantonio Debellis

    Full Text Available BACKGROUND: The pathogenicity of the Vibrio cholerae strains belonging to serogroup O1 and O139 is due to the production of virulence factors such as cholera toxin (CT and the toxin-coregulated pilus (TCP. The remaining serogroups, which mostly lack CT and TCP, are more frequently isolated from aquatic environmental sources than from clinical samples; nevertheless, these strains have been reported to cause human disease, such as sporadic outbreaks of watery diarrhoea and inflammatory enterocolitis. This evidence suggested the possibility that other virulence factor(s than cholera toxin might be crucial in the pathogenesis of Vibrio cholerae-induced diarrhoea, but their nature remains unknown. VCC, the hemolysin produced by virtually all Vibrio cholerae strains, has been proposed as a possible candidate, though a clear-cut demonstration attesting VCC as crucial in the pathogenesis of Vibrio cholerae-induced diarrhoea is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: Electrophysiological parameters and paracellular permeability of stripped human healthy colon tissues, obtained at subtotal colectomy, mounted in Ussing chamber were studied in the presence or absence of VCC purified from culture supernatants of V. cholerae O1 El Tor strain. Short circuit current (I(SC and transepithelial resistance (R(T were measured by a computerized voltage clamp system. The exposure of sigmoid colon specimens to 1 nM VCC resulted in an increase of I(SC by 20.7%, with respect to the basal values, while R(T was reduced by 12.3%. Moreover, increase in I(SC was abolished by bilateral Cl(- reduction. CONCLUSION/SIGNIFICANCE: Our results demonstrate that VCC, by forming anion channels on the apical membrane of enterocytes, triggers an outward transcellular flux of chloride. Such an ion movement, associated with the outward movement of Na(+ and water, might be responsible for the diarrhoea caused by the non-toxigenic strains of Vibrio cholerae.

  16. From cholera to corals: Viruses as drivers of virulence in a major coral bacterial pathogen

    KAUST Repository

    Weynberg, Karen D.

    2015-12-08

    Disease is an increasing threat to reef-building corals. One of the few identified pathogens of coral disease is the bacterium Vibrio coralliilyticus. In Vibrio cholerae, infection by a bacterial virus (bacteriophage) results in the conversion of non-pathogenic strains to pathogenic strains and this can lead to cholera pandemics. Pathogenicity islands encoded in the V. cholerae genome play an important role in pathogenesis. Here we analyse five whole genome sequences of V. coralliilyticus to examine whether virulence is similarly driven by horizontally acquired elements. We demonstrate that bacteriophage genomes encoding toxin genes with homology to those found in pathogenic V. cholerae are integrated in V. coralliilyticus genomes. Virulence factors located on chromosomal pathogenicity islands also exist in some strains of V. coralliilyticus. The presence of these genetic signatures indicates virulence in V. coralliilyticus is driven by prophages and other horizontally acquired elements. Screening for pathogens of coral disease should target conserved regions in these elements.

  17. Vibrio vulnificus Type 6 Secretion System 1 Contains Anti-Bacterial Properties.

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    Selina R Church

    Full Text Available Vibrio vulnificus is a bacterium responsible for severe gastroenteritis, sepsis and wound infections. Gastroenteritis and sepsis are commonly associated with the consumption of raw oysters, whereas wound infection is often associated with the handling of contaminated fish. Although classical virulence factors of this emerging pathogen are well characterised, there remains a paucity of knowledge regarding the general biology of this species. To investigate the presence of previously unreported virulence factors, we applied whole genome sequencing to a panel of ten V. vulnificus strains with varying virulence potentials. This identified two novel type 6 secretion systems (T6SSs, systems that are known to have a role in bacterial virulence and population dynamics. By utilising a range of molecular techniques and assays we have demonstrated the functionality of one of these T6SSs. Furthermore, we have shown that this system is subject to thermoregulation and is negatively regulated by increasing salinity concentrations. This secretion system was also shown to be involved in the killing of V. vulnificus strains that did not possess this system and a model is proposed as to how this interaction may contribute to population dynamics within V. vulnificus strains. In addition to this intra-species killing, this system also contributes to the killing of inter bacterial species and may have a role in the general composition of Vibrio species in the environment.

  18. Vibrio na água e sedimento de viveiros de quatro fazendas de carcinicultura no estado do Ceará, Brasil

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    Regine Helena Silva dos Fernandes Vieira

    2010-12-01

    Full Text Available Foram realizadas 16 coletas, oito no período chuvoso e oito no período de estio, em quatro fazendas de carcinicultura do Estado do Ceará, nos estuários dos rios Jaguaribe (fazendas A e B e Acaraú (fazendas C e D, totalizando 32 amostras. O objetivo da pesquisa foi quantificar e identificar Vibrio spp. nas amostras de água e sedimento. Os valores máximos da Contagem Padrão em Placas (CPP de Vibrio spp. encontrados para as amostras de água, no período chuvoso, foram de 5.10³ UFC/mL est. e, para o sedimento, de 7,5.10³ UFC/g est. No período de estio, a CPP máxima para água foi de 4,35.10² UFC/mL est. e de 3,55.10³ UFC/g est. para as amostras de sedimento. Foram obtidos 36 isolados de Vibrio: Vibrio spp. (17, V. vulnificus B1(3; V. calviensis (2, V. cholerae (2, V. litoralis (2, V. metschnikovii (2, V. agarivorans (1, V. alginolyticus (1, V. campbellii (1, V. coralliilyticus (1, V. diazotrophicus (1, V. logei (1, V. mediterranei (1, V. vulnificus B2 (1. O conhecimento da presença de espécies, nunca anteriormente isoladas em viveiros de fazendas de carcinicultura, tais como o V. coralliilyticus, V. agarivorans, V. litoralis e V. calviensis são importantes para o monitoramento microbiológico contínuo desses ambientes.

  19. Construction of a Vibrio splendidus Mutant Lacking the Metalloprotease Gene vsm by Use of a Novel Counterselectable Suicide Vector▿ †

    Science.gov (United States)

    Le Roux, Frédérique; Binesse, Johan; Saulnier, Denis; Mazel, Didier

    2007-01-01

    Vibrio splendidus is a dominant culturable Vibrio in seawater, and strains related to this species are also associated with mortality in a variety of marine animals. The determinants encoding the pathogenic properties of these strains are still poorly understood; however, the recent sequencing of the genome of V. splendidus LGP32, an oyster pathogen, provides an opportunity to decipher the basis of the virulence properties by disruption of candidate genes. We developed a novel suicide vector based on the pir-dependent R6K replicative origin, which potentially can be transferred by RP4-based conjugation to any Vibrio strain and which also carries the plasmid F toxin ccdB gene under control of the PBAD promoter. We demonstrated that this genetic system allows efficient counterselection of integrated plasmids in the presence of arabinose in both V. splendidus and Vibrio cholerae and thus permits efficient markerless allelic replacement in these species. We used this technique to construct several mutants of V. splendidus LGP32, including a derivative with a secreted metalloprotease gene, vsm, deleted. We found that this gene is essential for LGP32 extracellular product toxicity when the extracellular products are injected into oysters but is not necessary for virulence of bacteria in the oyster infection model when bacteria are injected. PMID:17122399

  20. Construction of a Vibrio splendidus mutant lacking the metalloprotease gene vsm by use of a novel counterselectable suicide vector.

    Science.gov (United States)

    Le Roux, Frédérique; Binesse, Johan; Saulnier, Denis; Mazel, Didier

    2007-02-01

    Vibrio splendidus is a dominant culturable Vibrio in seawater, and strains related to this species are also associated with mortality in a variety of marine animals. The determinants encoding the pathogenic properties of these strains are still poorly understood; however, the recent sequencing of the genome of V. splendidus LGP32, an oyster pathogen, provides an opportunity to decipher the basis of the virulence properties by disruption of candidate genes. We developed a novel suicide vector based on the pir-dependent R6K replicative origin, which potentially can be transferred by RP4-based conjugation to any Vibrio strain and which also carries the plasmid F toxin ccdB gene under control of the PBAD promoter. We demonstrated that this genetic system allows efficient counterselection of integrated plasmids in the presence of arabinose in both V. splendidus and Vibrio cholerae and thus permits efficient markerless allelic replacement in these species. We used this technique to construct several mutants of V. splendidus LGP32, including a derivative with a secreted metalloprotease gene, vsm, deleted. We found that this gene is essential for LGP32 extracellular product toxicity when the extracellular products are injected into oysters but is not necessary for virulence of bacteria in the oyster infection model when bacteria are injected.

  1. Genome Sequence of Vibrio campbellii Strain UMTGB204, a Marine Bacterium Isolated from a Green Barrel Tunicate

    Science.gov (United States)

    Gan, Huan You; Noor, Mohd Ezhar Mohd; Saari, Nur Azna; Musa, Najiah; Mustapha, Baharim; Usup, Gires

    2015-01-01

    Vibrio campbellii strain UMTGB204 was isolated from a green barrel tunicate. The genome of this strain comprises 5,652,224 bp with 5,014 open reading frames, 9 rRNAs, and 116 tRNAs. It contains genes related to virulence and environmental tolerance. Gene clusters for the biosynthesis of nonribosomal peptides and bacteriocin were also identified. PMID:25814609

  2. New Sequence Types of Vibrio parahaemolyticus Isolated from a Malaysian Aquaculture Pond, as Revealed by Whole-Genome Sequencing.

    Science.gov (United States)

    Foo, Soon Man; Eng, Wilhelm Wei Han; Lee, Yin Peng; Gui, Kimberly; Gan, Han Ming

    2017-05-11

    The acquisition of Photorhabdus insect-related (Pir) toxin-like genes in Vibrio parahaemolyticus has been linked to hepatopancreatic necrosis disease in shrimp. We report the whole-genome sequences of genetically virulent and avirulent V. parahaemolyticus isolated from a Malaysian aquaculture pond and show that they represent previously unreported sequence types of V. parahaemolyticus. Copyright © 2017 Foo et al.

  3. Occurrences of pathogenic Vibrio parahaemolyticus from Vellar ...

    African Journals Online (AJOL)

    Vibrio parahaemolyticus is the predominant seafood pathogen associated with human gastroenteritis. Samples were collected from Vellar estuary, shrimp ponds and shrimp for characterization of V. parahaemolyticus. A total of 26 blue green centre (BG) Vibrio strains were isolated and characterized through biochemical ...

  4. New Insights into Pathogenic Vibrios Affecting Bivalves in Hatcheries: Present and Future Prospects

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    Javier Dubert

    2017-05-01

    Full Text Available Hatcheries constitute nowadays the only viable solution to support the husbandry of bivalve molluscs due to the depletion and/or overexploitation of their natural beds. Hatchery activities include the broodstock conditioning and spawning, rearing larvae and spat, and the production of microalgae to feed all stages of the production cycle. However, outbreaks of disease continue to be the main bottleneck for successful larval and spat production, most of them caused by different representatives of the genus Vibrio. Therefore, attention must be paid on preventive and management measures that allow the control of such undesirable bacterial populations. The present review provides an updated picture of the recently characterized Vibrio species associated with disease of bivalve molluscs during early stages of development, including the controversial taxonomic affiliation of some of them and relevant advances in the knowledge of their virulence determinants. The problematic use of antibiotics, as well as its eco-friendly alternatives are also critically discussed.

  5. Comparative genome analysis of non-toxigenic non-O1 versus toxigenic O1 Vibrio cholerae.

    Science.gov (United States)

    Mukherjee, Munmun; Kakarla, Prathusha; Kumar, Sanath; Gonzalez, Esmeralda; Floyd, Jared T; Inupakutika, Madhuri; Devireddy, Amith Reddy; Tirrell, Selena R; Bruns, Merissa; He, Guixin; Lindquist, Ingrid E; Sundararajan, Anitha; Schilkey, Faye D; Mudge, Joann; Varela, Manuel F

    Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain, in order to identify novel genes potentially responsible for virulence. In this study, we compared the whole genome of the non-O1 PS15 strain to the whole genomes of toxigenic serotypes at the phylogenetic level, and found that the PS15 genome was distantly related to those of toxigenic V. cholerae. Thus we focused on a detailed gene comparison between PS15 and the distantly related O1 V. cholerae N16961. Based on sequence alignment we tentatively assigned chromosome numbers 1 and 2 to elements within the genome of non-O1 V. cholerae PS15. Further, we found that PS15 and O1 V. cholerae N16961 shared 98% identity and 766 genes, but of the genes present in N16961 that were missing in the non-O1 V. cholerae PS15 genome, 56 were predicted to encode not only for virulence-related genes (colonization, antimicrobial resistance, and regulation of persister cells) but also genes involved in the metabolic biosynthesis of lipids, nucleosides and sulfur compounds. Additionally, we found 113 genes unique to PS15 that were predicted to encode other properties related to virulence, disease, defense, membrane transport, and DNA metabolism. Here, we identified distinctive and novel genomic elements between O1 and non-O1 V. cholerae genomes as potential virulence factors and, thus, targets for future therapeutics. Modulation of such novel targets may eventually enhance eradication efforts of endemic and pandemic disease cholera in afflicted nations.

  6. The emergence of Vibrio pathogens in Europe: ecology, evolution, and pathogenesis (Paris, 11-12th March 2015).

    Science.gov (United States)

    Le Roux, Frédérique; Wegner, K Mathias; Baker-Austin, Craig; Vezzulli, Luigi; Osorio, Carlos R; Amaro, Carmen; Ritchie, Jennifer M; Defoirdt, Tom; Destoumieux-Garzón, Delphine; Blokesch, Melanie; Mazel, Didier; Jacq, Annick; Cava, Felipe; Gram, Lone; Wendling, Carolin C; Strauch, Eckhard; Kirschner, Alexander; Huehn, Stephan

    2015-01-01

    Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between fundamental and applied research in order to investigate the consequences of pathogen emergence in natural Vibrio populations and answer federative questions that meet societal needs. Here we report the proceedings of the first European workshop dedicated to these specific goals of the Vibrio research community by connecting current knowledge to societal issues related to ocean health and food security.

  7. The Emergence of Vibrio pathogens in Europe: Ecology, Evolution and Pathogenesis (Paris, 11-12 March 2015

    Directory of Open Access Journals (Sweden)

    Frederique eLe Roux

    2015-08-01

    Full Text Available Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between fundamental and applied research in order to investigate the consequences of pathogen emergence in natural Vibrio populations and answer federative questions that meet societal needs. Here we report the proceedings of the first European workshop dedicated to these specific goals of the Vibrio research community by connecting current knowledge to societal issues related to ocean health and food security.

  8. The emergence of Vibrio pathogens in Europe: ecology, evolution, and pathogenesis (Paris, 11–12th March 2015)

    Science.gov (United States)

    Roux, Frédérique Le; Wegner, K. Mathias; Baker-Austin, Craig; Vezzulli, Luigi; Osorio, Carlos R.; Amaro, Carmen; Ritchie, Jennifer M.; Defoirdt, Tom; Destoumieux-Garzón, Delphine; Blokesch, Melanie; Mazel, Didier; Jacq, Annick; Cava, Felipe; Gram, Lone; Wendling, Carolin C.; Strauch, Eckhard; Kirschner, Alexander; Huehn, Stephan

    2015-01-01

    Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between fundamental and applied research in order to investigate the consequences of pathogen emergence in natural Vibrio populations and answer federative questions that meet societal needs. Here we report the proceedings of the first European workshop dedicated to these specific goals of the Vibrio research community by connecting current knowledge to societal issues related to ocean health and food security. PMID:26322036

  9. Metalloprotease vsm is the major determinant of toxicity for extracellular products of Vibrio splendidus.

    Science.gov (United States)

    Binesse, Johan; Delsert, Claude; Saulnier, Denis; Champomier-Vergès, Marie-Christine; Zagorec, Monique; Munier-Lehmann, Hélène; Mazel, Didier; Le Roux, Frédérique

    2008-12-01

    Genomic data combined with reverse genetic approaches have contributed to the characterization of major virulence factors of Vibrio species; however, these studies have targeted primarily human pathogens. Here, we investigate virulence factors in the oyster pathogen Vibrio splendidus LGP32 and show that toxicity is correlated to the presence of a metalloprotease and its corresponding vsm gene. Comparative genomics showed that an avirulent strain closely related to LGP32 lacked the metalloprotease. The toxicity of LGP32 metalloprotease was confirmed by exposing mollusk and mouse fibroblastic cell lines to extracellular products (ECPs) of the wild type (wt) and a vsm deletion mutant (Deltavsm mutant). The ECPs of the wt induced a strong cytopathic effect whose severity was cell type dependent, while those of the Deltavsm mutant were much less toxic, and exposure to purified protein demonstrated the direct toxicity of the Vsm metalloprotease. Finally, to investigate Vsm molecular targets, a proteomic analysis of the ECPs of both LGP32 and the Deltavsm mutant was performed, revealing a number of differentially expressed and/or processed proteins. One of these, the VSA1062 metalloprotease, was found to have significant identity to the immune inhibitor A precursor, a virulence factor of Bacillus thuringiensis. Deletion mutants corresponding to several of the major proteins were constructed by allelic exchange, and the ECPs of these mutants proved to be toxic to both cell cultures and animals. Taken together, these data demonstrate that Vsm is the major toxicity factor in the ECPs of V. splendidus.

  10. Modeling and forecasting the distribution of Vibrio vulnificus in Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, John M.; Rhodes, M.; Brown, C. W.; Hood, Raleigh R.; Leight, A.; Long, Wen; Wood, R.

    2014-11-01

    The aim is to construct statistical models to predict the presence, abundance and potential virulence of Vibrio vulnificus in surface waters. A variety of statistical techniques were used in concert to identify water quality parameters associated with V. vulnificus presence, abundance and virulence markers in the interest of developing strong predictive models for use in regional oceanographic modeling systems. A suite of models are provided to represent the best model fit and alternatives using environmental variables that allow them to be put to immediate use in current ecological forecasting efforts. Conclusions: Environmental parameters such as temperature, salinity and turbidity are capable of accurately predicting abundance and distribution of V. vulnificus in Chesapeake Bay. Forcing these empirical models with output from ocean modeling systems allows for spatially explicit forecasts for up to 48 h in the future. This study uses one of the largest data sets compiled to model Vibrio in an estuary, enhances our understanding of environmental correlates with abundance, distribution and presence of potentially virulent strains and offers a method to forecast these pathogens that may be replicated in other regions.

  11. Modeling and forecasting the distribution of Vibrio vulnificus in Chesapeake Bay.

    Science.gov (United States)

    Jacobs, J M; Rhodes, M; Brown, C W; Hood, R R; Leight, A; Long, W; Wood, R

    2014-11-01

    To construct statistical models to predict the presence, abundance and potential virulence of Vibrio vulnificus in surface waters of Chesapeake Bay for implementation in ecological forecasting systems. We evaluated and applied previously published qPCR assays to water samples (n = 1636) collected from Chesapeake Bay from 2007-2010 in conjunction with State water quality monitoring programmes. A variety of statistical techniques were used in concert to identify water quality parameters associated with V. vulnificus presence, abundance and virulence markers in the interest of developing strong predictive models for use in regional oceanographic modeling systems. A suite of models are provided to represent the best model fit and alternatives using environmental variables that allow them to be put to immediate use in current ecological forecasting efforts. Environmental parameters such as temperature, salinity and turbidity are capable of accurately predicting abundance and distribution of V. vulnificus in Chesapeake Bay. Forcing these empirical models with output from ocean modeling systems allows for spatially explicit forecasts for up to 48 h in the future. This study uses one of the largest data sets compiled to model Vibrio in an estuary, enhances our understanding of environmental correlates with abundance, distribution and presence of potentially virulent strains and offers a method to forecast these pathogens that may be replicated in other regions. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  12. Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas harvested in the south bay of Santa Catarina island, Brazil Ocorrência de Vibrio spp., estafilococos coagulase positivo e bactérias entéricas em ostras (Crassostrea gigas cultivadas na baía sul da ilha de Santa Catarina, Brasil

    Directory of Open Access Journals (Sweden)

    Roberta Juliano Ramos

    2012-09-01

    Full Text Available The aim of this study was to assess the contamination of oysters (Crassostrea gigas, harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10% samples showed presence of Escherichia coli, 15 (8.3% samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%. The counts of positive-coagulase staphylococci varied from O objetivo deste estudo foi avaliar a contaminação de ostras (Crassostrea gigas cultivadas em diferentes regiões da Baía Sul da Ilha de Santa Catarina, por coliformes a 45 ºC, Escherichia coli, Vibrio spp. Estafilococos coagulase positiva e Salmonella sp., durante o período de um ano. Foram analisadas 180 amostras, coletadas diretamente no local de cultivo. Todas as amostras analisadas apresentaram ausência de Salmonella, 18 (10% amostras apresentaram presença de Escherichia coli, 15 (8,3% amostras positivas para Vibrio alginolyticus e V. cholerae foi detectado em 4 amostras (2,2%. As contagens de Estafilococos coagulase positiva variaram de <10 a 1,9 x 102 UFC.g-1, enquanto que as contagens de coliformes a 45 ºC e E. coli variaram de <3 a 1,5 x 102 NMP.g-1 e <3 e 4,3 x 10 NMP.g-1, respectivamente. As contagens de V. parahaemolyticus e V. vulnificus variaram de <3 a 7 NMP.g-1, para ambos os microrganismos, sugerindo um monitoramento tanto destas espécies quanto da temperatura das águas marinhas nas regiões de cultivo. Com base nos resultados das análises microbiológicas, as amostras analisadas mostraram qualidade bacteriológica aceitável, ou seja, dentro dos parâmetros estabelecidos na legislação brasileira.

  13. Experimental infection with different bacterial strains in larvae and juvenile Litopenaeus vannamei reared in Santa Catarina State, Brazil - doi: 10.4025/actascibiolsci.v32i3.5471 Experimental infection with different bacterial strains in larvae and juvenile Litopenaeus vannamei reared in Santa Catarina State, Brazil - doi: 10.4025/actascibiolsci.v32i3.5471

    Directory of Open Access Journals (Sweden)

    Adolfo Jatoba

    2010-09-01

    Full Text Available This study evaluated the pathogenic characteristics of bacteria isolated from Litopenaeus vannamei during an outbreak at the Laboratory of Marine Shrimp, UFSC, Santa Catarina State, Brazil. Their virulence potential in larvae and juvenile shrimp and the effects on the total haemocyte count, phenoloxidase activity and serum agglutinate titre were examined after experimental infection. Bacterial strains were isolated from larvae and adult shrimps, identified by the AP120E biochemical system as: two strains of Vibrio alginolyticus, three of Aeromonas salmonicida and one of Pasteurella multocida sp. and Pasteurella sp. All the bacterial strains isolated in this study caused mortality in shrimp. One strain of V. alginolyticus was responsible for 97.3 and 88.7% mortality in larvae and juvenil shrimps, respectively. The shrimp immunological system was influenced by experimental infection with V. alginolyticus. Decrease in the total haemocyte count and increase in the phenoloxidase activity and the serum agglutinate titre (p V. alginolyticus isolated from larvae and juvenile reared marine shrimp.This study evaluated the pathogenic characteristics of bacteria isolated from Litopenaeus vannamei during an outbreak at the Laboratory of Marine Shrimp, UFSC, Santa Catarina State, Brazil. Their virulence potential in larvae and juvenile shrimp and the effects on the total haemocyte count, phenoloxidase activity and serum agglutinate titre were examined after experimental infection. Bacterial strains were isolated from larvae and adult shrimps, identified by the AP120E biochemical system as: two strains of Vibrio alginolyticus, three of Aeromonas salmonicida and one of Pasteurella multocida sp. and Pasteurella sp. All the bacterial strains isolated in this study caused mortality in shrimp. One strain of V. alginolyticus was responsible for 97.3 and 88.7% mortality in larvae and juvenil shrimps, respectively. The shrimp immunological system was influenced by

  14. A Comprehensive Epidemiological Research for Clinical Vibrio parahaemolyticus in Shanghai

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    Huan Li

    2017-06-01

    Full Text Available Vibrio parahaemolyticus is one of the most important pathogen for seafood-borne gastroenteritis in Shanghai and the rest of the world. A total of 42 V. parahaemolyticus strains were isolated from 1900 fecal specimens collected from patients in Shanghai hospital presenting from January 2014 to December 2015. All isolates were evaluated for potential virulence factors [tdh, trh, and type three secretion system (T3SS genes], typed using multilocus sequence typing (MLST and screened for antimicrobial resistance phenotype and genotype. And for the first time, the relationship between virulence, genetic diversity and antimicrobial resistance of these isolates were identified. The results showed that 37 isolates carried the tdh gene (88.1% and only seven isolates were positive for the trh gene. The T3SS1 and T3SS2 genes were detected in all strains and only trh-positive isolates are also containing the T3SS2β genes. MLST analysis of the 42 Shanghai isolates identified 20 sequence types (STs with 16 novel STs and that these clinical V. parahaemolyticus strains showed high degrees of genetic diversity. All isolates expressed high levels of resistance against Ampicillin (100.0%, Streptomycin (100.0%, Cephazolin (92.9%, Kanamycin (92.8% and Amikacin (90.5%, and eight out of 38 resistance genes (SHV, tet(B, strA, qnrA, gryA, qnrB, sulI, sulII were detected in at least two isolates. This study confirms that antimicrobial resistance of clinical V. parahaemolyticus isolates is greater than those of environmental isolates. Furthermore, no clear correlation between antimicrobial resistance and virulence or genetic diversity was found in this study. These results add to epidemiological data of clinical V. parahaemolyticus isolates in Shanghai and highlight the need for additional mechanistic studies, especially antimicrobial resistance, to reduce the burden of disease caused by this pathogen in China.

  15. Occurrences of pathogenic Vibrio parahaemolyticus from Vellar ...

    African Journals Online (AJOL)

    user

    2013-04-03

    2001). Vibrio vulnificus as a health hazard for shrimp consumers. Revista do Instituto de Medicina Tropical de Sao Paulo. 43: 263- 266. Sambrook J, Fritsch EF, Maniatis T (1989). Molecular Cloning: A. Laboratory Manual, 2nd ed.

  16. Roles of thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH in Vibrio parahaemolyticus

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    Pendru eRaghunath

    2015-01-01

    Full Text Available Vibrio parahaemolyticus is the leading cause of seafood borne bacterial gastroenteritis in the world, often associated with the consumption of raw or undercooked seafood. However, not all strains of V. parahaemolyticus are pathogenic. The thermostable direct haemolysin (TDH or TDH-related haemolysin (TRH encoded by tdh and trh genes, respectively are considered major virulence factors in V. parahaemolyticus. However, about 10% of clinical strains do not contain tdh and/or trh. Environmental isolates of V. parahaemolyticus lacking tdh and/or trh are also highly cytotoxic to human gastrointestinal cells. Even in the absence of these hemolysins, V. parahaemolyticus remains pathogenic indicating other virulence factors exist. This mini review aims at discussing the possible roles of tdh and trh genes in clinical and environmental isolates of V. parahaemolyticus.

  17. Roles of thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) in Vibrio parahaemolyticus.

    Science.gov (United States)

    Raghunath, Pendru

    2014-01-01

    Vibrio parahaemolyticus is the leading cause of seafood borne bacterial gastroenteritis in the world, often associated with the consumption of raw or undercooked seafood. However, not all strains of V. parahaemolyticus are pathogenic. The thermostable direct hemolysin (TDH) or TDH-related hemolysin (TRH) encoded by tdh and trh genes, respectively, are considered major virulence factors in V. parahaemolyticus. However, about 10% of clinical strains do not contain tdh and/or trh. Environmental isolates of V. parahaemolyticus lacking tdh and/or trh are also highly cytotoxic to human gastrointestinal cells. Even in the absence of these hemolysins, V. parahaemolyticus remains pathogenic indicating other virulence factors exist. This mini review aims at discussing the possible roles of tdh and trh genes in clinical and environmental isolates of V. parahaemolyticus.

  18. Vibrio chromosomes share common history

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    Gevers Dirk

    2010-05-01

    Full Text Available Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II were identified from 19 sequenced Vibrionales genomes and their phylogenetic comparison suggests consistent phylogenies for each chromosome. Additionally, study of the gene organization and phylogeny of the respective origins of replication confirmed the shared history. Conclusions Thus, while elements within the chromosomes may have experienced significant genetic mobility, the backbones share a common history. This allows conclusions based on multilocus sequence analysis (MLSA for one chromosome to be applied equally to both chromosomes.

  19. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Skovgaard, Ole; Ducos-Galand, Magaly

    2012-01-01

    importance in public health, Vibrio cholerae, the causative agent of cholera, has become a preferred model to study bacteria with multipartite genomes. However, most in vivo studies in V. cholerae have been hampered by its genome architecture, as it is difficult to give phenotypes to a specific chromosome....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...... in V. cholerae and the general question concerning bacteria carrying circular chromosomes--by looking at the effect of chromosome size on topological issues. In this article, we show that Dam, RctB, and ParA2/ParB2 are strictly essential for chrII origin maintenance, and we formally demonstrate...

  20. Antibiotic Susceptibility Patterns of Vibrio cholerae isolates

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    S D Shrestha

    2010-09-01

    Full Text Available INTRODUCTION: Cholera is one of the most common diarrhoeal diseases in Nepal. Etiological agent of cholera is Vibrio cholerae which removes essential body fluids, salts and vital nutrients, which are necessary for life causing dehydration and malnutrition. Emerging antimicrobial resistant is common. The aim of the present study was to determine the antibiotic susceptibility pattern of cholera patients in Nepal. METHODS: All the laboratory works were conducted in the bacteriology section of National Public Health Laboratory, Teku from March to September 2005. During this period a total of 340 stool samples from diarrhoeal patients were collected and processed according to the standard laboratory methods. Each patient suffering from diarrhoea was directly interviewed for his or her clinical history during sample collection. RESULTS: A total of 340 stool samples were processed and studied from both sex including all ages of patients. Among the processed sample 53 Vibrio cholerae cases were found. All isolated Vibrio cholerae O1 were El Tor, Inaba. All isolated (100% Vibrio cholerae O1 were sensitive to Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline whereas all were resistant to Nalidixic acid and Cotrimoxazole. Only 15.1% cases were sensitive to Furazolidone whereas 84.9% were resistant. CONCLUSION: All V. cholerae strains isolated in this study were found resistant to Multi Drug Resistant (resistant to at least two antibiotics of different group. Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline were found still more potent antibiotics against Vibrio cholerae isolated during the study. Keywords: antibiotics, susceptibility, Vibrio cholera.

  1. Hatchery mortalities of larval oysters caused by Vibrio tubiashii and Vibrio coralliilyticus

    Science.gov (United States)

    Hatchery production of bivalve shellfish has been hampered by the occasional presence of opportunistic pathogens, particularly Vibrio coralliilyticus and Vibrio tubiashii. The present study reports the results of several avenues of research to better define these pathogens and the roles they play i...

  2. Vibrio vulnificus infection in São Paulo, Brazil: case report and literature review

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    Maria Rita Elmor de Araujo

    Full Text Available Non cholera Vibrio may cause conjunctivitis, wound infection, gastroenteritis and serious sepsis. Transmission to men is through contact with skin, mucosa or wounds exposed to marine water, and consumption of certain barely cooked or raw seafood, more frequently in the summer. This is one of the first cases of severe infection related to Vibrio vulnificus described in Brazil. The patient was an old man, who ingested seafood in Guarujá, a seashore city near São Paulo, 3 days before hospitalization. He was admitted to the emergency room in an ill state with septic shock. On 2 sets of blood culture a highly virulent microorganism was isolated, Vibrio vulnificus, which leads to sepsis and frequently to death in susceptible patients. The objective of this report was to use this case to discuss clinical aspects, microbiological diagnosis and treatment of the infection caused by this agent, besides the review of epidemiology, associated risk factors and prevention before consuming or getting in contact with seafood, especially in patients with greater susceptibility to this kind of infection.

  3. [Pathogenicity island region of clinical and environmental strains of Vibrio parahaemolyticus, isolated in Chile].

    Science.gov (United States)

    Núñez, Harold; Ulloa, María Teresa; Guerra, Fabiola; Osorio, Carlos G

    2009-02-01

    Most clinical isolates of Vibrio parahaemolyticus produce a major virulence factor known as the thermostable direct hemolysin (TDH). TDH is encoded by the tdh gene which is located in a genomic pathogenicity island (PAI). Most environmental isolates are described as tdh negative. To assess if environmental strains lack the full pathogenicity island or if only the tdh gene is deleted. Thirty eight clinical and 66 environmental strains of Vibrio parahaemolyticus were studied. PAI was characterized by polymerase chain reaction (PCR). The presence of tdhA and tdhS genes, was determined by Southern blot. Fifty three environmental strains (80%) lacked a full PAI when compared with clinical strains. In environmental strains, Southern blot and sequence analysis showed that a genetic region of 80 kilobase pairs including genes from VPA1310 to VPA1396 was missing. These results highlight the genetic dynamism of Vibrio parahaemolyticus pathogenecity island region and suggest that new pathogenic strains could appear by horizontal transfer of the island between toxigenic and non-toxigenic strains.

  4. Rapid proliferation of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae during freshwater flash floods in French Mediterranean coastal lagoons.

    Science.gov (United States)

    Esteves, Kevin; Hervio-Heath, Dominique; Mosser, Thomas; Rodier, Claire; Tournoud, Marie-George; Jumas-Bilak, Estelle; Colwell, Rita R; Monfort, Patrick

    2015-11-01

    Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae of the non-O1/non-O139 serotype are present in coastal lagoons of southern France. In these Mediterranean regions, the rivers have long low-flow periods followed by short-duration or flash floods during and after heavy intense rainstorms, particularly at the end of the summer and in autumn. These floods bring large volumes of freshwater into the lagoons, reducing their salinity. Water temperatures recorded during sampling (15 to 24°C) were favorable for the presence and multiplication of vibrios. In autumn 2011, before heavy rainfalls and flash floods, salinities ranged from 31.4 to 36.1‰ and concentrations of V. parahaemolyticus, V. vulnificus, and V. cholerae varied from 0 to 1.5 × 10(3) most probable number (MPN)/liter, 0.7 to 2.1 × 10(3) MPN/liter, and 0 to 93 MPN/liter, respectively. Following heavy rainstorms that generated severe flash flooding and heavy discharge of freshwater, salinity decreased, reaching 2.2 to 16.4‰ within 15 days, depending on the site, with a concomitant increase in Vibrio concentration to ca. 10(4) MPN/liter. The highest concentrations were reached with salinities between 10 and 20‰ for V. parahaemolyticus, 10 and 15‰ for V. vulnificus, and 5 and 12‰ for V. cholerae. Thus, an abrupt decrease in salinity caused by heavy rainfall and major flooding favored growth of human-pathogenic Vibrio spp. and their proliferation in the Languedocian lagoons. Based on these results, it is recommended that temperature and salinity monitoring be done to predict the presence of these Vibrio spp. in shellfish-harvesting areas of the lagoons. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. [Comparative genomic analysis of vibrio cholerae El Tor preseventh and seventh pandemic strains isolated in various periods].

    Science.gov (United States)

    Osin, A V; Nefedov, K S; Eroshenko, G A; Smirnova, N I

    2005-01-01

    Genetic organization of 52 Vibrio cholerae El Tor biotype preseventh and seventh pandemic strains isolated in various periods was studied by PCR assay and DNA-DNA hybridization. It was established that the genome of most ancient of analyzed strains isolated from a diarrhea patient in 1910 was devoid of CTX and RS1 prophages, vibrio pathogenicity islands (VPI and VPI-2), and pandemic islands (VSP-1 and VSP-2) that contain key virulence genes. The appearance of pathogenic properties in cholera vibrios for the first time causing a local outbreak of cholera in 1937 is connected with the acquisition of VPI and CTX that carried genes tcpA and ctx-AB, respectively, which are responsible for the colonization of small intestine and encode the production of cholera toxin. The appearance of seventh pandemic agent for cholera was shown to correlate with the acquisition by its precursor of two additional blocks of genes VSP-1 and VSP-2. This finding strongly supports the involvement of these genes in formation of the pandemic potential in strains. Molecular typing methods allowed elucidation of differences in the genetic organization between prepandemic and pandemic strains. The detected variability of the genome of contemporary virulent strains may be a reason for the occurrence of etiological agent for cholera with new properties.

  6. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  7. Galleria mellonella: A model of infection to discern novel mechanisms of pathogenesis of non-toxigenic Vibrio parahaemolyticus strains.

    Science.gov (United States)

    Pérez-Reytor, Diliana; García, Katherine

    2017-10-05

    Vibrio parahaemolyticus is a leading cause of raw seafood-associated bacterial gastroenteritis in the world. Its pathogenesis is likely to be multifactorial, although the most characteristic virulence-associated factors are the toxins TDH and TRH, in addition to the Type-III Secretion System-2, which codes for diverse effectors involved in cytotoxicity and enterotoxicity. However, diarrhea cases produced by clinical strains lacking all of these main virulence factors (non-toxigenic strains) have been reported in many countries and they can represent up to 9-10% of the clinical isolations. So far, although there have been significant advances in the description of the virulence factors of V. parahaemolyticus, the ability of non-toxigenic strains to cause illness is still not completely understood. To elucidate this question it is necessary to have adequate infection models. The susceptibility of G. mellonella to the infection with non-toxigenic strains seems to be the response to identifying new virulence factors and consequently providing new insights into mechanisms of the virulence of non-toxigenic strains. This new model means an invaluable contribution to public health, since the understanding of virulence in strains lacking the traditional major toxins is essential to detect these strains present in waters and marine products and avoid possible food-borne infection.

  8. A comparative epizootiologic study of the two fish-pathogenic serovars of Vibrio vulnificus biotype 2.

    Science.gov (United States)

    Fouz, B; Llorens, A; Valiente, E; Amaro, C

    2010-05-01

    Vibrio vulnificus biotype 2 is subdivided into two main serovars, serovar E, able to infect fish and humans, and serovar A, only virulent for fish. Serovar E emerged in 1976 as the causative agent of a haemorrhagic septicaemia (warm-water vibriosis) affecting eels cultured in brackish water. Serovar A emerged in 2000 in freshwater-cultured eels vaccinated against serovar E, causing warm-water vibriosis with fish showing a haemorrhagic intestine as the main differential sign. The aim of the present work was to compare the disease caused by both serovars in terms of transmission routes, portals of entry and host range. Results of bath, patch-contact and oral-anal challenges demonstrated that both serovars spread through water and infect healthy eels, serovar A entering mainly by the anus and serovar E by the gills. The course of the disease under laboratory conditions was similar for both serovars in terms of transmission and dependence of degree of virulence on water parameters (temperature and salinity). However, the decrease in degree of virulence in fresh water was significantly greater in serovar E than in serovar A. Finally, both serovars proved pathogenic for tilapia, sea bass and rainbow trout, but not for sea bream, with significant differences in degree of virulence only in rainbow trout. In conclusion, serovar A seems to represent a new antigenic form of V. vulnificus biotype 2 with an unusual portal of entry and is better adapted to fresh water than serovar E.

  9. Hfq regulates the expression of the thermostable direct hemolysin gene in Vibrio parahaemolyticus.

    Science.gov (United States)

    Nakano, Masayuki; Takahashi, Akira; Su, Zehong; Harada, Nagakatsu; Mawatari, Kazuaki; Nakaya, Yutaka

    2008-09-21

    The hfq gene is conserved in a wide variety of bacteria and Hfq is involved in many cellular functions such as stress responses and the regulation of gene expression. It has also been reported that Hfq is involved in bacterial pathogenicity. However, it is not clear whether Hfq regulates virulence in Vibrio parahaemolyticus. To evaluate this, we investigated the effect of Hfq on the expression of virulence-associated genes including thermostable direct hemolysin (TDH), which is considered to be an important virulence factor in V. parahaemolyticus, using an hfq deletion mutant. The production of TDH in the hfq deletion mutant was much higher than in the parental strain. Quantification of tdh promoter activity and mRNA demonstrated that transcription of the tdh gene was up-regulated in the mutant strain. The hfq-complemented strain had a normal (parental) amount of tdh expression. The transcriptional activity of tdhA was particularly increased in the mutant strain. These results indicate that Hfq is closely associated with the expression level of the tdh gene. Interestingly, other genes involved in the pathogenicity of V. parahaemolyticus, such as VP1680, vopC, and vopT, were also up-regulated in the mutant strain. Hfq regulates the expression of virulence-associated factors such as TDH and may be involved in the pathogenicity of V. parahaemolyticus.

  10. Hfq regulates the expression of the thermostable direct hemolysin gene in Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Mawatari Kazuaki

    2008-09-01

    Full Text Available Abstract Background The hfq gene is conserved in a wide variety of bacteria and Hfq is involved in many cellular functions such as stress responses and the regulation of gene expression. It has also been reported that Hfq is involved in bacterial pathogenicity. However, it is not clear whether Hfq regulates virulence in Vibrio parahaemolyticus. To evaluate this, we investigated the effect of Hfq on the expression of virulence-associated genes including thermostable direct hemolysin (TDH, which is considered to be an important virulence factor in V. parahaemolyticus, using an hfq deletion mutant. Results The production of TDH in the hfq deletion mutant was much higher than in the parental strain. Quantification of tdh promoter activity and mRNA demonstrated that transcription of the tdh gene was up-regulated in the mutant strain. The hfq-complemented strain had a normal (parental amount of tdh expression. The transcriptional activity of tdhA was particularly increased in the mutant strain. These results indicate that Hfq is closely associated with the expression level of the tdh gene. Interestingly, other genes involved in the pathogenicity of V. parahaemolyticus, such as VP1680, vopC, and vopT, were also up-regulated in the mutant strain. Conclusion Hfq regulates the expression of virulence-associated factors such as TDH and may be involved in the pathogenicity of V. parahaemolyticus.

  11. Complete Genome Sequence of Vibrio campbellii LMB 29 Isolated from Red Drum with Four Native Megaplasmids

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    Jinxin Liu

    2017-10-01

    Full Text Available Vibrio spp. are the most common pathogens for animals reared in aquaculture. Vibrio campbellii, which is often involved in shrimp, fish and mollusks diseases, is widely distributed in the marine environment worldwide, but our knowledge about its pathogenesis and antimicrobial resistance is very limited. The existence of this knowledge gap is at least partially because that V. campbellii was originally classified as Vibrio harveyi, and the detailed information of its comparative genome analysis to other Vibrio spp. is currently lacking. In this study, the complete genome of a V. campbellii predominant strain, LMB29, was determined by MiSeq in conjunction with PacBio SMRT sequencing. This genome consists of two circular DNA chromosomes and four megaplasmids. Comparative genome analysis indicates that LMB29 shares a 96.66% similarity (average nucleotide identity with the V. campbellii ATCC strain BAA-1116 based on a 75% AF (average fraction calculations, and its functional profile is very similar to V. campbellii E1 and V. campbellii CAIM115. Both type III secretion system (T3SS and type VI secretion system (T6SS, along with the tlh gene which encodes a thermolabile hemolysin, are present in LMB29 which may contribute to the bacterial pathogenesis. The virulence of this strain was experimental confirmed by performing a LDH assay on a fish cell infection model, and cell death was observed as early as within 3 h post infection. Thirty-seven antimicrobial resistance genes (>45% identity were predicted in LMB29 which includes a novel rifampicin ADP ribosyltransferase, arr-9, in plasmid pLMB157. The gene arr-9 was predicted on a genomic island with horizontal transferable potentials which may facilitate the rifampicin resistance dissemination. Future researches are needed to explore the pathogenesis of V. campbellii LMB29, but the availability of this genome sequence will certainly aid as a basis for further analysis.

  12. Interaction of Vibrio spp. with the Inner Surface of the Digestive Tract of Penaeus monodon.

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    Wipasiri Soonthornchai

    Full Text Available Several species of Vibrio are the causative agent of gastroenteritis in humans. In aquaculture, Vibrio harveyi (Vh and V. parahaemolyticus (Vp have long been considered as shrimp pathogens in freshwater, brackish and marine environments. Here we show by using scanning electron microscopy (SEM that Penaeus monodon orally inoculated with each of these two pathogens via an Artemia diet had numerous bacteria attached randomly across the stomach surface, in single and in large biofilm-like clusters 6 h post-infection. A subsequent marked proliferation in the number of V. harveyi within the biofilm-like formations resulted in the development of infections in the stomach, the upper and middle midgut, but neither in the posterior midgut nor the hindgut. SEM also revealed the induced production of peritrichous pili-like structures by the Vp attaching to the stomach lining, whilst only a single polar fibre was seen forming an apparent physical bridge between Vh and the host's epithelium. In contrast to these observations, no such adherences or linkages were seen when trials were conducted with non-pathogenic Vibrio spp. or with Micrococcus luteus, with no obvious resultant changes to the host's gut surface. In naive shrimp, the hindgut was found to be a favorable site for bacteria notably curved, short-rod shaped bacteria which probably belong to Vibrio spp. Data from the current study suggests that pathogens of P. monodon must be able to colonize the digestive tract, particularly the stomach, where chitin is present, and then they use an array of virulent factors and enzymes to infect their host resulting in disease. Oral infection is a better way of mimicking natural routes of infection; investigating the host-bacteria interactions occurring in the digestive tract may lead to new strategies for the prevention or control of bacterial infections in penaeids.

  13. Interaction of Vibrio spp. with the Inner Surface of the Digestive Tract of Penaeus monodon

    Science.gov (United States)

    Soonthornchai, Wipasiri; Chaiyapechara, Sage; Jarayabhand, Padermsak; Söderhäll, Kenneth; Jiravanichpaisal, Pikul

    2015-01-01

    Several species of Vibrio are the causative agent of gastroenteritis in humans. In aquaculture, Vibrio harveyi (Vh) and V. parahaemolyticus (Vp) have long been considered as shrimp pathogens in freshwater, brackish and marine environments. Here we show by using scanning electron microscopy (SEM) that Penaeus monodon orally inoculated with each of these two pathogens via an Artemia diet had numerous bacteria attached randomly across the stomach surface, in single and in large biofilm-like clusters 6 h post-infection. A subsequent marked proliferation in the number of V. harveyi within the biofilm-like formations resulted in the development of infections in the stomach, the upper and middle midgut, but neither in the posterior midgut nor the hindgut. SEM also revealed the induced production of peritrichous pili-like structures by the Vp attaching to the stomach lining, whilst only a single polar fibre was seen forming an apparent physical bridge between Vh and the host’s epithelium. In contrast to these observations, no such adherences or linkages were seen when trials were conducted with non-pathogenic Vibrio spp. or with Micrococcus luteus, with no obvious resultant changes to the host’s gut surface. In naive shrimp, the hindgut was found to be a favorable site for bacteria notably curved, short-rod shaped bacteria which probably belong to Vibrio spp. Data from the current study suggests that pathogens of P. monodon must be able to colonize the digestive tract, particularly the stomach, where chitin is present, and then they use an array of virulent factors and enzymes to infect their host resulting in disease. Oral infection is a better way of mimicking natural routes of infection; investigating the host-bacteria interactions occurring in the digestive tract may lead to new strategies for the prevention or control of bacterial infections in penaeids. PMID:26285030

  14. Effects of Global Warming on Vibrio Ecology.

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Brettar, Ingrid; Höfle, Manfred; Pruzzo, Carla

    2015-06-01

    Vibrio-related infections are increasing worldwide both in humans and aquatic animals. Rise in global sea surface temperature (SST), which is approximately 1 °C higher now than 140 years ago and is one of the primary physical impacts of global warming, has been linked to such increases. In this chapter, major known effects of increasing SST on the biology and ecology of vibrios are described. They include the effects on bacterial growth rate, both in the field and in laboratory, culturability, expression of pathogenicity traits, and interactions with aquatic organisms and abiotic surfaces. Special emphasis is given to the effect of ocean warming on Vibrio interactions with zooplankters, which represent one of the most important aquatic reservoirs for these bacteria. The reported findings highlight the biocomplexity of the interactions between vibrios and their natural environment in a climate change scenario, posing the need for interdisciplinary studies to properly understand the connection between ocean warming and persistence and spread of vibrios in sea waters and the epidemiology of the diseases they cause.

  15. Suspension of oysters reduces the populations of Vibrio parahaemolyticus and Vibrio vulnificus.

    Science.gov (United States)

    Cole, K M; Supan, J; Ramirez, A; Johnson, C N

    2015-09-01

    Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) are associated with the consumption of raw oysters and cause illnesses ranging from simple gastroenteritis to life-threatening septicaemia. These halophilic bacteria are frequently found in marine and estuarine systems, accumulating within the tissues of a number of aquatic organisms and passing on to humans after consumption, through contaminated water, or via open wounds. As benthic organisms capable of filtering 40 gallons of water per hour, sediment is an important source of potentially pathogenic vibrios in oysters destined for raw consumption. This research used off-bottom oyster culture to reduce vibrio concentrations in oysters. Colony hybridization was used to enumerate Vp and Vv in bottom and suspended oysters. Vv and Vp concentrations were generally lower in oysters suspended off-bottom, and suspension decreased vibrio loads in oysters by an average of 13%. Suspension of oysters reduced vibrio concentrations. This study found that oyster suspension significantly reduced some populations of potentially pathogenic vibrios. These results indicate that oyster suspension could be a viable approach for preharvest treatment to reduce illness in consumers of raw oysters. © 2015 The Society for Applied Microbiology.

  16. RpoS controls the Vibrio cholerae mucosal escape response.

    Directory of Open Access Journals (Sweden)

    Alex Toftgaard Nielsen

    2006-10-01

    Full Text Available Vibrio cholerae causes a severe diarrhoeal disease by secreting a toxin during colonization of the epithelium in the small intestine. Whereas the initial steps of the infectious process have been intensively studied, the last phases have received little attention. Confocal microscopy of V. cholerae O1-infected rabbit ileal loops captured a distinctive stage in the infectious process: 12 h post-inoculation, bacteria detach from the epithelial surface and move into the fluid-filled lumen. Designated the "mucosal escape response," this phenomenon requires RpoS, the stationary phase alternative sigma factor. Quantitative in vivo localization assays corroborated the rpoS phenotype and showed that it also requires HapR. Expression profiling of bacteria isolated from ileal loop fluid and mucus demonstrated a significant RpoS-dependent upregulation of many chemotaxis and motility genes coincident with the emigration of bacteria from the epithelial surface. In stationary phase cultures, RpoS was also required for upregulation of chemotaxis and motility genes, for production of flagella, and for movement of bacteria across low nutrient swarm plates. The hapR mutant produced near-normal numbers of flagellated cells, but was significantly less motile than the wild-type parent. During in vitro growth under virulence-inducing conditions, the rpoS mutant produced 10- to 100-fold more cholera toxin than the wild-type parent. Although the rpoS mutant caused only a small over-expression of the genes encoding cholera toxin in the ileal loop, it resulted in a 30% increase in fluid accumulation compared to the wild-type. Together, these results show that the mucosal escape response is orchestrated by an RpoS-dependent genetic program that activates chemotaxis and motility functions. This may furthermore coincide with reduced virulence gene expression, thus preparing the organism for the next stage in its life cycle.

  17. Temporal and spatial variability in culturable pathogenic Vibrio spp. in Lake Pontchartrain, Louisiana, following hurricanes Katrina and Rita.

    Science.gov (United States)

    Nigro, Olivia D; Hou, Aixin; Vithanage, Gayatri; Fujioka, Roger S; Steward, Grieg F

    2011-08-01

    We investigated the abundance, distribution, and virulence gene content of Vibrio cholerae, V. parahaemolyticus, and V. vulnificus in the waters of southern Lake Pontchartrain in Louisiana on four occasions from October 2005 to September 2006, using selective cultivation and molecular assays. The three targeted pathogenic vibrios were generally below the detection level in January 2006, when the water was cold (13°C), and most abundant in September 2006, when the lake water was warmest (30°C). The maximum values for these species were higher than reported previously for the lake by severalfold to orders of magnitude. The only variable consistently correlated with total vibrio abundance within a single sampling was distance from shore (P = 0.000). Multiple linear regression of the entire data set revealed that distance from shore, temperature, and turbidity together explained 82.1% of the variability in total vibrio CFU. The log-transformed mean abundance of V. vulnificus CFU in the lake was significantly correlated with temperature (P = 0.014), but not salinity (P = 0.625). Virulence-associated genes of V. cholerae (ctx) and V. parahaemolyticus (trh and tdh) were not detected in any isolates of these species (n = 128 and n = 20, respectively). In contrast, 16S rRNA typing of V. vulnificus (n = 298) revealed the presence of both environmental (type A) and clinical (type B) strains. The percentage of the B-type V. vulnificus was significantly higher in the lake in October 2005 (35.8% of the total) than at other sampling times (P ≤ 0.004), consistent with the view that these strains represent distinct ecotypes.

  18. Genetic characterization of trh positive Vibrio spp. isolated from Norway

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    Anette eBauer Ellingsen

    2013-12-01

    Full Text Available The thermostable direct hemolysin (TDH and/or TDH-related hemolysin (TRH genes are carried by most virulent Vibrio parahaemolyticus serovars. In Norway, trh+ V. parahaemolyticus constitute 4.4% and 4.5 % of the total number of V. parahaemolyticus isolated from blue mussel (Mytilus edulis and water, respectively. The trh gene is located in a region close to the gene cluster for urease production (ure. This region was characterized in V. parahaemolyticus strain TH3996 and it was found that a nickel transport operon (nik was located between the first gene (ureR and the rest of the ure cluster genes. The organization of the trh-ureR-nik-ure gene cluster in the Norwegian trh+ isolates was unknown. In this study, we explore the gene organization within the trh-ureR-nik-ure cluster for these isolates. PCR analyses revealed that the genes within the trh-ureR-nik-ure gene cluster of Norwegian trh+ isolates were organized in a similar fashion as reported previously for TH33996. Additionally, the phylogenetic relationship among these trh+ isolates was investigated using Multilocus Sequence Typing (MLST. Analysis by MLST or ureR-trh sequences generated two different phylogenetic trees for the same strains analyzed, suggesting that ureR-trh genes have been acquired at different times in Norwegian V. parahaemolyticus isolates. MLST results revealed that some pathogenic and non-pathogenic V. parahaemolyticus isolates in Norway appear to be highly genetically related.

  19. Quorum Sensing in the Squid-Vibrio Symbiosis

    Directory of Open Access Journals (Sweden)

    Tim Miyashiro

    2013-08-01

    Full Text Available Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.

  20. Quorum Sensing in the Squid-Vibrio Symbiosis

    Science.gov (United States)

    Verma, Subhash C.; Miyashiro, Tim

    2013-01-01

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

  1. Genetic characterization of trh positive Vibrio spp. isolated from Norway.

    Science.gov (United States)

    Ellingsen, Anette B; Olsen, Jaran S; Granum, Per E; Rørvik, Liv M; González-Escalona, Narjol

    2013-01-01

    The thermostable direct hemolysin (TDH) and/or TDH-related hemolysin (TRH) genes are carried by most virulent Vibrio parahaemolyticus serovars. In Norway, trh+ V. parahaemolyticus constitute 4.4 and 4.5% of the total number of V. parahaemolyticus isolated from blue mussel (Mytilus edulis) and water, respectively. The trh gene is located in a region close to the gene cluster for urease production (ure). This region was characterized in V. parahaemolyticus strain TH3996 and it was found that a nickel transport operon (nik) was located between the first gene (ureR) and the rest of the ure cluster genes. The organization of the trh-ureR-nik-ure gene cluster in the Norwegian trh+ isolates was unknown. In this study, we explore the gene organization within the trh-ureR-nik-ure cluster for these isolates. PCR analyses revealed that the genes within the trh-ureR-nik-ure gene cluster of Norwegian trh+ isolates were organized in a similar fashion as reported previously for TH33996. Additionally, the phylogenetic relationship among these trh+ isolates was investigated using Multilocus Sequence Typing (MLST). Analysis by MLST or ureR-trh sequences generated two different phylogenetic trees for the same strains analyzed, suggesting that ureR-trh genes have been acquired at different times in Norwegian V. parahaemolyticus isolates. MLST results revealed that some pathogenic and non-pathogenic V. parahaemolyticus isolates in Norway appear to be highly genetically related.

  2. Quorum sensing in the squid-Vibrio symbiosis.

    Science.gov (United States)

    Verma, Subhash C; Miyashiro, Tim

    2013-08-07

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.

  3. Metalloprotease Vsm Is the Major Determinant of Toxicity for Extracellular Products of Vibrio splendidus▿ †

    Science.gov (United States)

    Binesse, Johan; Delsert, Claude; Saulnier, Denis; Champomier-Vergès, Marie-Christine; Zagorec, Monique; Munier-Lehmann, Hélène; Mazel, Didier; Le Roux, Frédérique

    2008-01-01

    Genomic data combined with reverse genetic approaches have contributed to the characterization of major virulence factors of Vibrio species; however, these studies have targeted primarily human pathogens. Here, we investigate virulence factors in the oyster pathogen Vibrio splendidus LGP32 and show that toxicity is correlated to the presence of a metalloprotease and its corresponding vsm gene. Comparative genomics showed that an avirulent strain closely related to LGP32 lacked the metalloprotease. The toxicity of LGP32 metalloprotease was confirmed by exposing mollusk and mouse fibroblastic cell lines to extracellular products (ECPs) of the wild type (wt) and a vsm deletion mutant (Δvsm mutant). The ECPs of the wt induced a strong cytopathic effect whose severity was cell type dependent, while those of the Δvsm mutant were much less toxic, and exposure to purified protein demonstrated the direct toxicity of the Vsm metalloprotease. Finally, to investigate Vsm molecular targets, a proteomic analysis of the ECPs of both LGP32 and the Δvsm mutant was performed, revealing a number of differentially expressed and/or processed proteins. One of these, the VSA1062 metalloprotease, was found to have significant identity to the immune inhibitor A precursor, a virulence factor of Bacillus thuringiensis. Deletion mutants corresponding to several of the major proteins were constructed by allelic exchange, and the ECPs of these mutants proved to be toxic to both cell cultures and animals. Taken together, these data demonstrate that Vsm is the major toxicity factor in the ECPs of V. splendidus. PMID:18836018

  4. Prevalence of Vibrio parahaemolyticus, and Vibrio vulnificus in blue crabs (Callinectes sapidus), seawater and sediments of the Maryland Coastal Bays.

    Science.gov (United States)

    Rodgers, C; Parveen, S; Chigbu, P; Jacobs, J; Rhodes, M; Harter-Dennis, J

    2014-10-01

    To determine the prevalence of total and pathogenic Vibrio parahaemolyticus (Vp) and V. vulnificus (Vv) in blue crabs, water and sediment from the Maryland Coastal Bays (MCBs), USA. Crab, haemolymph, sediment and seawater samples were collected monthly from four sites in MCBs from February 2012 through October 2012 with environmental parameters recorded. The most-probable-number (MPN) methodology was used to enumerate Vp and Vv with presumptive colonies and the presence of virulence markers confirmed using polymerase chain reaction (PCR). Results indicate that blue crabs contained both Vp and Vv at densities (7·28 and 5·43 log MPN g(-1) , respectively) higher than those reported for bivalves. In addition, markers for clinically relevant strains of both species were detected in over 30% of samples. Haemolymph, sediment and seawater samples were also routinely positive for both species and clinically relevant strains, but generally at lower densities than found in crabs (4·27, 3·28, and 2·39 log MPN g(-1) per ml(-1) Vp, and 4·28, 2·49 and 2·38 log MPN g(-1) per ml(-1) Vv). Blue crabs concentrate Vp and Vv at levels greater than found in water or sediment. While changes in abundance associated with temperature are apparent, there is little evidence to support differences among sampling locations. These results highlight the potential for blue crab related vibriosis and the importance of proper handling, cooking and care of this popular seafood before consumption. © 2014 The Society for Applied Microbiology.

  5. Vibrio population structure - Genetic and population structure analysis of clinical and environmental Vibrio parahaemolyticus strains

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vibrio parahaemolyticus (Vp) is a marine bacterium capable of causing severe gastroenteritis in humans, usually through the consumption of raw shellfish. Before...

  6. Vibrio ecology - Identifying Environmental Determinants Favorable for the Presence and Transmission of Pathogenic Vibrios

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In a tri-coastal collaborative study, the population densities of vibrios are being determined in the Mississippi Sound, Puget Sound, Chesapeake Bay, and Timbalier...

  7. Entry of Vibrio harveyi and Vibrio fischeri into the viable but nonculturable state

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah; Ravel, J.; Straube, W.L.; Hill, R.T.; Colwell, R.R.

    Physical responses of marine luminous bacteria, Vibrio harveyi (ATCC 14216) and V. fischeri (UM1373) to nutrient-limited normal strength (35 ppt iso-osmolarity) and low (10 ppt hypo-osmolarity) salinity conditions were determined. Plate counts...

  8. Characterization of htrB and msbB mutants of the light organ symbiont Vibrio fischeri.

    Science.gov (United States)

    Adin, Dawn M; Phillips, Nancy J; Gibson, Bradford W; Apicella, Michael A; Ruby, Edward G; McFall-Ngai, Margaret J; Hall, Daniel B; Stabb, Eric V

    2008-02-01

    Bacterial lipid A is an important mediator of bacterium-host interactions, and secondary acylations added by HtrB and MsbB can be critical for colonization and virulence in pathogenic infections. In contrast, Vibrio fischeri lipid A stimulates normal developmental processes in this bacterium's mutualistic host, Euprymna scolopes, although the importance of lipid A structure in this symbiosis is unknown. To further examine V. fischeri lipid A and its symbiotic function, we identified two paralogs of htrB (designated htrB1 and htrB2) and an msbB gene in V. fischeri ES114 and demonstrated that these genes encode lipid A secondary acyltransferases. htrB2 and msbB are found on the Vibrio "housekeeping" chromosome 1 and are conserved in other Vibrio species. Mutations in htrB2 and msbB did not impair symbiotic colonization but resulted in phenotypic alterations in culture, including reduced motility and increased luminescence. These mutations also affected sensitivity to sodium dodecyl sulfate, kanamycin, and polymyxin, consistent with changes in membrane permeability. Conversely, htrB1 is located on the smaller, more variable vibrio chromosome 2, and an htrB1 mutant was wild-type-like in culture but appeared attenuated in initiating the symbiosis and was outcompeted 2.7-fold during colonization when mixed with the parent. These data suggest that htrB2 and msbB play conserved general roles in vibrio biology, whereas htrB1 plays a more symbiosis-specific role in V. fischeri.

  9. Isolation and characterization of antimicrobial peptides derived from Bacillus subtilis E20-fermented soybean meal and its use for preventing Vibrio infection in shrimp aquaculture.

    Science.gov (United States)

    Cheng, Ann-Chang; Lin, Hsueh-Li; Shiu, Ya-Li; Tyan, Yu-Chang; Liu, Chun-Hung

    2017-08-01

    Bacillus subtilis E20-fermented soybean meal (FSBM) was found to produce antimicrobial peptides (AMPs) with great antimicrobial activity against Vibrio alginolyticus (VA) and V. parahaemolyticus (VP). Three AMPs were purified with a 5 kDa ultrafiltration, Sephadex G-15 column and reverse-phase high-performance liquid chromatography (RP-HPLC). The FSB-AMP, HTSKALLDMLKRLGK, identified by an RP-nano-ultrapure liquid chromatography (UPLC) electrospray ionization (ESI)-tandem mass spectroscopic (MS/MS) analysis exhibited the highest bactericidal activity against VA and VP compared to the others. The antimicrobial activity assessment indicated that FSB-AMP inhibited the growth of VA and VP with minimal inhibitory concentrations of 72.5 and 72.5 μM. Alterations in the morphology of VA were observed by scanning electronic microscopy, and membrane disruption of VA and VP was confirmed by fluorescent microscopy with propidium iodide staining. The FSB-AMP was then incorporated into the diet of white shrimp, Litopenaeus vannamei, and a protective effect in shrimp against VP infection was recorded as well as for shrimp fed a diet containing 15% fish meal replaced by B. subtilis E20-FSBM. Results demonstrated that B. subtilis E20-FSBM could be a biofunctional ingredient to prevent vibriosis in shrimp aquaculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Benthic ecology of Vibrio spp. and pathogenic Vibrio species in a coastal Mediterranean environment (La Spezia Gulf, Italy).

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Moreno, Mariapaola; Fabiano, Mauro; Pane, Luigi; Pruzzo, Carla

    2009-11-01

    We carried out a 16-month in situ study to investigate the ecology of Vibrio spp. and pathogenic Vibrio species in coastal sediments of the Mediterranean Sea, employing multiple-regression analysis to reveal the major environmental factors controlling their occurrence in the benthic environment. In addition, association between vibrios and sediment-inhabiting meiofauna, which is a major component of benthic ecosystems, was investigated. Culturable and total Vibrio spp. estimates by most-probable-number technique coupled with standard polymerase chain reaction (PCR) and real-time PCR methods, respectively, were at least one order of magnitude higher in sediment than in seawater. In addition, potential human pathogenic species Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus occurred in the sediment with V. parahaemolyticus being the most frequently found. In the pelagic environment, 60% of total variance in culturable Vibrio data was explained by sea surface temperature (40%), salinity (13%) and organic matter concentration (7%). In the benthic environment, sea surface temperature was the only factor that significantly affected culturable Vibrio occurrence although it explained only 25% of total variance, suggesting that additional unexplored factors may play a role as well. No correlation was found between culturable Vibrio spp. concentrations and the abundance of harpacticoid copepods in the sediment whilst a negative correlation was found between Vibrio spp. and nematode abundance which accounted for almost 90% of the total meiofaunal density. Taxonomic analysis revealed that selective bacterial feeders accounted for nearly 50% of the total nematode community and included genera such as Terschellingia, Molgolaimus and Halalaimus, suggesting that top-down control by nematode grazing may be an important factor affecting Vibrio occurrence in these sediments. It is concluded that the benthic marine environment may function as a reservoir of Vibrio spp

  11. Antimicrobial susceptibilty of potentially pathogenic halophilic Vibrio ...

    African Journals Online (AJOL)

    Surveillance of antimicrobial resistance is indispensable for empirical treatment of infections and in preventing the spread of antimicrobial resistant microorganisms. This study is aimed at determining the antibiotic susceptibility of potentially pathogenic halophylic Vibrio species isolated in Lagos, Nigeria. Susceptibility ...

  12. Organic metabolites produced by Vibrio parahaemolyticus strain ...

    African Journals Online (AJOL)

    Identification and action of several antibacterial metabolites produced by a fish pathogen Vibrio parahaemolyticus strain An3 from marine ecosystem of Goa has been demonstrated. Antibacterial activity of the crude cell extract of the test bacterium has been evaluated against indicator pathogenic bacterial strains such as ...

  13. Avaliação de bacterina e Lactobacillus plantarum frente à infecção experimental por Vibrio harveyi em pós-larvas de Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Celso Carlos Buglione

    2008-12-01

    Full Text Available This study aimed to verify the effect of probiotics and inactivated cells of bacterias such as Vibrio alginolyticus, Aeromonas salmonicida and Pasteurella multocida in larvae survival of Litopenaeus vannamei, in stress test and experimental infection with Vibrio harveyi. Conic tanks of 30 L, were stocked with 400 post-larvae stage five. Four experimental treatments with triplicates consisted of: 1: commercial feed (control, 2: commercial feed plus bacterin by oral administration in artemia, 3: commercial feed plus bacterin by immersion administration, 4: commercial feed with Lactobacillus plantarum inoculation. Bacterin application was conducted 6h before the infection and stress test, while probiotic administration was for 15 days before challenges. In stress test, post-larvae of treatment 4 (commercial feed supplemented with Lactobacillus plantarum with reached the highest survival rate (87,86 ± 2,35% followed by the ones of treatment 3 and 2 (bacterim by immersion and bacterim by oral administration in artemia with 81,54±1,50% and 80,16 ± 2,15%, respectively, which were superior to the control treatment (72,63 ± 3,34%. Next to V. harveyi challenge, animals from treatment 3 presented the highest survival rate (79,60 ± 7,12% followed by treatments 4 (69,60 ± 10,43%, 2 (65,60 ± 5,18% and control (56,4 ± 5,58%. All treatments were different from control. The present results demonstrate the possible use of L. plantarum and bacterin as promoters in survival rates of L. vannamei post-larvae in the stress tests and challenges with Vibrio harveyi.

  14. Plankton composition and environmental factors contribute to Vibrio seasonality.

    Science.gov (United States)

    Turner, Jeffrey W; Good, Brooks; Cole, Dana; Lipp, Erin K

    2009-09-01

    Plankton represent a nutrient-rich reservoir capable of enriching Vibrio species, which can include human pathogens, at higher densities than the surrounding water column. To better understand the relationship between vibrios and plankton, the partitioning of culturable vibrios, on TCBS, between free living and plankton associated (63-200- and >200-microm-size fractions) was monitored over a 1-year period in coastal waters of Georgia, USA. Seasonal changes in the total Vibrio concentration were then compared with changes in environmental parameters as well as changes in the relative composition of the plankton community. Using univariate analyses, Vibrio concentrations were strongly associated with temperature, especially when those vibrios were plankton associated (R(2)=0.69 and 0.88 for the water and both plankton fractions; respectively) (Pplankton fractions were also correlated to shifts in the relative abundance of specific plankton taxa. In the 63-200-micro fraction, Vibrio concentrations were inversely associated with copepods, cyanobacteria and diatoms. In the >200-micro fraction, Vibrio concentrations were positively associated with copepods and negatively associated with decapod larvae. Our results confirm the role of temperature in Vibrio seasonality and highlight an important and independent role for plankton composition in explaining seasonal changes in Vibrio concentration.

  15. Pathogenetic characterization of Vibrio parahaemolyticus isolates from clinical and seafood sources.

    Science.gov (United States)

    Vongxay, Khamphouth; Wang, Shuna; Zhang, Xiaofeng; Wu, Beibei; Hu, Hongxia; Pan, Zijiang; Chen, Suyun; Fang, Weihuan

    2008-08-15

    A total of 216 Vibrio parahaemolyticus isolates from seafood and clinical samples in eastern China were investigated for their hemolytic and urea-producing phenotypes, presence of putative virulence genes tdh and trh. Twenty-one clinical isolates (84%, 21/25) and 3 seafood isolates (1.57%, 3/191) were tdh-positive while only 3 clinical isolates (12%) and 7 seafood isolates (3.66%) were positive for trh gene. We further examined the pathogenicity of selected V. parahaemolyticus isolates in in vitro and in vivo systems. The clinical isolates were apparently more enteropathogenic (74.26 per thousand vs 62.07 per thousand expressed as intestine/body weight ratio, Pcytotoxicity as measured by LDH release of the HeLa cells although there were no statistical differences. The tdh-positive V. parahaemolyticus isolates were of higher enteropathogenicity (Pcytotoxic and adhesive to the cultured cell lines as well. From the in vitro and in vivo pathogenicity profiles, trh-positive isolates seemed to line between tdh-positive isolates and those without tdh and trh. There were two isolates H8 and H10 from clinical cases having moderate enteropathogenicity and virulence to mice, but were tdh-negative yet trh-positive. These results seem to suggest that hemolysins TDH and/or TRH may not be necessarily the only virulence factors of pathogenic V. parahaemolyticus isolates.

  16. Vibrio cholerae hemolysin is required for lethality, developmental delay, and intestinal vacuolation in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Hediye Nese Cinar

    Full Text Available BACKGROUND: Cholera toxin (CT and toxin-co-regulated pili (TCP are the major virulence factors of Vibrio cholerae O1 and O139 strains that contribute to the pathogenesis of disease during devastating cholera pandemics. However, CT and TCP negative V. cholerae strains are still able to cause severe diarrheal disease in humans through mechanisms that are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: To determine the role of other virulence factors in V. cholerae pathogenesis, we used a CT and TCP independent infection model in the nematode Caenorhabditis elegans and identified the hemolysin A (hlyA gene as a factor responsible for animal death and developmental delay. We demonstrated a correlation between the severity of infection in the nematode and the level of hemolytic activity in the V. cholerae biotypes. At the cellular level, V. cholerae infection induces formation of vacuoles in the intestinal cells in a hlyA dependent manner, consistent with the previous in vitro observations. CONCLUSIONS/SIGNIFICANCE: Our data strongly suggest that HlyA is a virulence factor in C. elegans infection leading to lethality and developmental delay presumably through intestinal cytopathic changes.

  17. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  18. Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from retail shrimps in Malaysia

    Directory of Open Access Journals (Sweden)

    Vengadesh eLetchumanan

    2015-01-01

    Full Text Available Vibrio parahaemolyticus is a marine and estuarine bacterium that has been the leading cause of foodborne outbreaks which leads to a significant threat to human health worldwide. Consumption of seafood contaminated with Vibrio parahaemolyticus causes acute gastroenteritis in individuals. The bacterium poses two main virulence factor including the thermostable direct hemolysin (tdh which is a pore-forming protein that contributes to the invasiveness of the bacterium in humans and TDH-related hemolysin (trh, which plays a similar role as thermostable direct hemolysin (tdh in the disease pathogenesis. This study aimed to investigate the antimicrobial resistance Vibrio parahaemolyticus strains in shrimps purchased from wetmarkets and supermarkets. The toxR-based PCR assay indicated that a total of 57.8% (185/320 isolates were positive for V. parahaemolyticus. Only 10% (19/185 toxR-positive isolate exhibit the TDH-related hemolysin (trh gene and none of the isolates were tested positive for thermostable direct hemolysin (tdh. The MAR index was measured for 14 common antimicrobial agents. The results indicated 98% of the isolates were highly susceptible to imipenem, ampicillin sulbactam (96%, chloramphenicol (95%, trimethoprim-sulfamet (93%, gentamicin (85%, levofloxacin (83% and tetracycline (82%. The chloramphenicol (catA2 and kanamycin (aphA-3 resistance genes were detected in the resistant V. parahaemolyticus isolates. Our results demonstrate that shrimps are contaminated with V. parahaemolyticus, some of which carry the trh-gene thus being potential to cause food borne illness. The occurrence of multidrug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields.

  19. Transformation Experiment Using Bioluminescence Genes of "Vibrio fischeri."

    Science.gov (United States)

    Slock, James

    1995-01-01

    Bioluminescence transformation experiments show students the excitement and power of recombinant DNA technology. This laboratory experiment utilizes two plasmids of "Vibrio fischeri" in a transformation experiment. (LZ)

  20. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Science.gov (United States)

    2010-04-01

    ... cholera caused by the bacterium Vibrio cholerae and provides epidemiological information on cholera. Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and electrolyte...

  1. Vaccination in three different ways against vibriosis of Seriola dumerili caused by Vibrio hollisae

    Science.gov (United States)

    Ji, Rongxing; Zou, Wenzheng; Hu, Shiliu; Yan, Qingpi

    2008-08-01

    Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili (amberjack) suffering from vibriosis. Healthy S. dumerili were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1:40 at 7 d, and reached its peak of 1:320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of vaccinated fish exhibited significantly higher lysozyme activities ( Pvaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.

  2. Vibrio vulnificus produces quorum sensing signals of the AHL-class

    DEFF Research Database (Denmark)

    Valiente, E.; Bruhn, Jesper Bartholin; Nielsen, Kristian Fog

    2009-01-01

    Vibrio vulnificus is an aquatic pathogenic bacterium that can cause vibriosis in humans and fish. The species is subdivided into three biotypes with the fish-virulent strains belonging to biotype 2. The quorum sensing (QS) phenomenon mediated by furanosyl borate diester or autoinducer 2 (AI-2) ha...... biotype 2 strains. No known AHL-related gene was detected by PCR or Southern blot suggesting that AHL-related genes in V. vulnificus are different from those found in other Gram-negative bacteria....... was detected when AHL-positive strains were grown in low-nutrient medium [modified sea water yeast extract (MSWYE)] but not in rich media (tryptic soy broth or brain–heart infusion) and its production was enhanced when blood factors were added to MSWYE. C4-HL was detected in vivo, in eels infected with AHL-positive...

  3. Strategies of Vibrio parahaemolyticus to acquire nutritional iron during host colonization

    Science.gov (United States)

    León-Sicairos, Nidia; Angulo-Zamudio, Uriel A.; de la Garza, Mireya; Velázquez-Román, Jorge; Flores-Villaseñor, Héctor M.; Canizalez-Román, Adrian

    2015-01-01

    Iron is an essential element for the growth and development of virtually all living organisms. As iron acquisition is critical for the pathogenesis, a host defense strategy during infection is to sequester iron to restrict the growth of invading pathogens. To counteract this strategy, bacteria such as Vibrio parahaemolyticus have adapted to such an environment by developing mechanisms to obtain iron from human hosts. This review focuses on the multiple strategies employed by V. parahaemolyticus to obtain nutritional iron from host sources. In these strategies are included the use of siderophores and xenosiderophores, proteases and iron-protein receptor. The host sources used by V. parahaemolyticus are the iron-containing proteins transferrin, hemoglobin, and hemin. The implications of iron acquisition systems in the virulence of V. parahaemolyticus are also discussed. PMID:26217331

  4. Comparative Genomics of Vibrio cholerae O1 Isolated from Cholera Patients in Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Leekitcharoenphon, Pimlapas; Dalsgaard, Anders

    AIM: Cholera remains an endemic disease in Bangladesh and recently, the severity of the disease has significantly increased in urban area since the emergence of the new variant of Vibrio cholerae O1 El Tor. In this study, Whole Genome Sequencing (WGS) was utilized to investigate the current genomic...... profile of V. cholerae O1 strains, isolated from symptomatic patients in the low-income urban area of Arichpur, Dhaka, Bangladesh. METHODS: During October 2015, three V. cholerae O1 strains (VC-1, 2 and 3) were isolated from rectal swabs of two patients living in households 588 m apart. One of the two...... patients was co-infected with two V. cholerae strains (VC-1 and VC-3). Major virulence factors, biotype and antimicrobial resistance genes were identified by WGS. A global phylogenetic tree was inferred using genome wide SNPs (Single Nucleotide Polymorphism) analysis. RESULTS: All the V. cholerae strains...

  5. Cholix Toxin, a Novel ADP-ribosylating Factor from Vibrio cholerae

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, Rene; Purdy, Alexandra E.; Fieldhouse, Robert J.; Kimber, Matthew S.; Bartlett, Douglas H.; Merrill, A. Rod (Guelph); (NIH); (UCSD)

    2008-07-15

    The ADP-ribosyltransferases are a class of enzymes that display activity in a variety of bacterial pathogens responsible for causing diseases in plants and animals, including those affecting mankind, such as diphtheria, cholera, and whooping cough. We report the characterization of a novel toxin from Vibrio cholerae, which we call cholix toxin. The toxin is active against mammalian cells (IC50 = 4.6 {+-} 0.4 ng/ml) and crustaceans (Artemia nauplii LD50 = 10 {+-} 2 {mu}g/ml). Here we show that this toxin is the third member of the diphthamide-specific class of ADP-ribose transferases and that it possesses specific ADP-ribose transferase activity against ribosomal eukaryotic elongation factor 2. We also describe the high resolution crystal structures of the multidomain toxin and its catalytic domain at 2.1- and 1.25-{angstrom} resolution, respectively. The new structural data show that cholix toxin possesses the necessary molecular features required for infection of eukaryotes by receptor-mediated endocytosis, translocation to the host cytoplasm, and inhibition of protein synthesis by specific modification of elongation factor 2. The crystal structures also provide important insight into the structural basis for activation of toxin ADP-ribosyltransferase activity. These results indicate that cholix toxin may be an important virulence factor of Vibrio cholerae that likely plays a significant role in the survival of the organism in an aquatic environment.

  6. Cloning, expressing, and hemolysis of tdh, trh and tlh genes of Vibrio parahaemolyticus

    Science.gov (United States)

    Zhao, Yonggang; Tang, Xiaoqian; Zhan, Wenbin

    2011-09-01

    Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea, Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors. They are thermostable direct hemolysin (TDH), TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR). We ligated the three genes into prokaryotic expression vector pET-28a (+), and transformed the recombinant plasmids into Escherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins, TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis. The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes' functions under a single factor level, but also provide evidence for VP vaccine engineering.

  7. Laboratory simulation reveals significant impacts of ocean acidification on microbial community composition and host-pathogen interactions between the blood clam and Vibrio harveyi.

    Science.gov (United States)

    Zha, Shanjie; Liu, Saixi; Su, Wenhao; Shi, Wei; Xiao, Guoqiang; Yan, Maocang; Liu, Guangxu

    2017-12-01

    It has been suggested that climate change may promote the outbreaks of diseases in the sea through altering the host susceptibility, the pathogen virulence, and the host-pathogen interaction. However, the impacts of ocean acidification (OA) on the pathogen components of bacterial community and the host-pathogen interaction of marine bivalves are still poorly understood. Therefore, 16S rRNA high-throughput sequencing and host-pathogen interaction analysis between blood clam (Tegillarca granosa) and Vibrio harveyi were conducted in the present study to gain a better understanding of the ecological impacts of ocean acidification. The results obtained revealed a significant impact of ocean acidification on the composition of microbial community at laboratory scale. Notably, the abundance of Vibrio, a major group of pathogens to many marine organisms, was significantly increased under ocean acidification condition. In addition, the survival rate and haemolytic activity of V. harveyi were significantly higher in the presence of haemolymph of OA treated T. granosa, indicating a compromised immunity of the clam and enhanced virulence of V. harveyi under future ocean acidification scenarios. Conclusively, the results obtained in this study suggest that future ocean acidification may increase the risk of Vibrio pathogen infection for marine bivalve species, such as blood clams. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Vibrio cholerae Infection of Drosophilamelanogaster Mimics the Human Disease Cholera.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Cholera, the pandemic diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, continues to be a major public health challenge in the developing world. Cholera toxin, which is responsible for the voluminous stools of cholera, causes constitutive activation of adenylyl cyclase, resulting in the export of ions into the intestinal lumen. Environmental studies have demonstrated a close association between V. cholerae and many species of arthropods including insects. Here we report the susceptibility of the fruit fly, Drosophila melanogaster, to oral V. cholerae infection through a process that exhibits many of the hallmarks of human disease: (i death of the fly is dependent on the presence of cholera toxin and is preceded by rapid weight loss; (ii flies harboring mutant alleles of either adenylyl cyclase, Gsalpha, or the Gardos K channel homolog SK are resistant to V. cholerae infection; and (iii ingestion of a K channel blocker along with V. cholerae protects wild-type flies against death. In mammals, ingestion of as little as 25 mug of cholera toxin results in massive diarrhea. In contrast, we found that ingestion of cholera toxin was not lethal to the fly. However, when cholera toxin was co-administered with a pathogenic strain of V. cholerae carrying a chromosomal deletion of the genes encoding cholera toxin, death of the fly ensued. These findings suggest that additional virulence factors are required for intoxication of the fly that may not be essential for intoxication of mammals. Furthermore, we demonstrate for the first time the mechanism of action of cholera toxin in a whole organism and the utility of D. melanogaster as an accurate, inexpensive model for elucidation of host susceptibility to cholera.

  9. Assay development and high-throughput screening for small molecule inhibitors of a Vibrio cholerae stress response pathway

    Directory of Open Access Journals (Sweden)

    Stanbery L

    2017-09-01

    Full Text Available Laura Stanbery, Jyl S Matson Department of Medical Microbiology and Immunology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, USA Abstract: Antibiotics are important adjuncts to oral rehydration therapy in cholera disease management. However, due to the rapid emergence of resistance to the antibiotics used to treat cholera, therapeutic options are becoming limited. Therefore, there is a critical need to develop additional therapeutics to aid in the treatment of cholera. Previous studies showed that the extracytoplasmic stress response (σE pathway of Vibrio cholerae is required for full virulence of the organism. The pathway is also required for bacterial growth in the presence of ethanol. Therefore, we exploited this ethanol sensitivity phenotype in order to develop a screen for inhibitors of the pathway, with the aim of also inhibiting virulence of the pathogen. Here we describe the optimization and implementation of our high-throughput screening strategy. From a primary screen of over 100,000 compounds, we have identified seven compounds that validated the growth phenotypes from the primary and counterscreens. These compounds have the potential to be developed into therapeutic agents for cholera and will also be valuable probes for uncovering basic molecular mechanisms of an important cause of diarrheal disease. Keywords: Vibrio cholerae, stress response, σE, high-throughput screening

  10. Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico.

    Directory of Open Access Journals (Sweden)

    Iliana Guardiola-Avila

    Full Text Available Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883 were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix. Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins. According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution.

  11. Development of a loop-mediated Isothermal amplification assay for sensitive and rapid detection of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Kawahara Ryuji

    2008-09-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a marine seafood-borne pathogen causing gastrointestinal disorders in humans. Thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH are known as major virulence determinants of V. parahaemolyticus. Most V. parahaemolyticus isolates from the environment do not produce TDH or TRH. Total V. parahaemolyticus has been used as an indicator for control of seafood contamination toward prevention of infection. Detection of total V. parahaemolyticus using conventional culture- and biochemical-based assays is time-consuming and laborious, requiring more than three days. Thus, we developed a novel and highly specific loop-mediated isothermal amplification (LAMP assay for the sensitive and rapid detection of Vibrio parahaemolyticus. Results The assay provided markedly more sensitive and rapid detection of V. parahaemolyticus strains than conventional biochemical and PCR assays. The assay correctly identified 143 V. parahaemolyticus strains, but did not detect 33 non-parahaemolyticus Vibrio and 56 non-Vibrio strains. Sensitivity of the LAMP assay for direct detection of V. parahaemolyticus in pure cultures and in spiked shrimp samples was 5.3 × 102 CFU per ml/g (2.0 CFU per reaction. The sensitivity of the LAMP assay was 10-fold more sensitive than that of the conventional PCR assay. The LAMP assay was markedly faster, requiring for amplification 13–22 min in a single colony on TCBS agar from each of 143 V. parahaemolyticus strains and less than 35 min in spiked shrimp samples. The LAMP assay for detection of V. parahaemolyticus required less than 40 min in a single colony on thiosulfate citrate bile salt sucrose (TCBS agar and 60 min in spiked shrimp samples from the beginning of DNA extraction to final determination. Conclusion The LAMP assay is a sensitive, rapid and simple tool for the detection of V. parahaemolyticus and will facilitate the surveillance for control of contamination of V

  12. Carriage of vibrio species by shrimps harvested from the coastal ...

    African Journals Online (AJOL)

    Objectives: To determine the prevalence of Vibrio spp in unprocessed shrimps and their susceptibility to antibiotics. Design: A prospective study of Vibrio spp associated with shrimps harvested from the coastal waters of South West Cameroon. Setting: A laboratory based study at the Department of Life Sciences, University ...

  13. Brucella, nitrogen and virulence.

    Science.gov (United States)

    Ronneau, Severin; Moussa, Simon; Barbier, Thibault; Conde-Álvarez, Raquel; Zuniga-Ripa, Amaia; Moriyon, Ignacio; Letesson, Jean-Jacques

    2016-08-01

    The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.

  14. Environmental occurrence and clinical impact of Vibrio vulnificus and Vibrio parahaemolyticus: a European perspective.

    Science.gov (United States)

    Baker-Austin, Craig; Stockley, Louise; Rangdale, Rachel; Martinez-Urtaza, Jaime

    2010-02-01

    Vibrio vulnificus and Vibrio parahaemolyticus are ubiquitous Gram-negative bacterial pathogens found naturally in marine and estuarine waters, and are a leading cause of seafood-associated bacterial illness. These pathogens are commonly reported in the USA and in many Asian countries, including China, Japan and Taiwan; however, there is growing concern that V. vulnificus and V. parahaemolyticus may represent an important and increasing clinical problem in Europe. Several factors underlie the need for a greater understanding of these non-cholera vibrios within a European context. First, there is a growing body of evidence to suggest that V. vulnificus and V. parahaemolyticus infections are increasing, and tend to follow regional climatic trends, with outbreaks typically following episodes of unusually warm weather. Such findings are especially alarming given current predictions regarding warming of marine waters as a result of global climatic change. Second, a myriad of epidemiological factors may greatly increase the incidence as well as clinical burden of these pathogens - including increasing global consumption and trade of seafood produce coupled to an increase in the number of susceptible individuals consuming seafood produce. Finally, there is currently a lack of detailed surveillance information regarding non-cholerae Vibrio infections in Europe, as these pathogens are not notifiable in many countries, which probably masks the true clinical burden of many human infections. This review will present a pertinent overview of both the environmental occurrence and clinical impact of V. vulnificus and V. parahaemolyticus in Europe. © 2010 Crown copyright.

  15. Effects of ambient exposure, refrigeration, and icing on Vibrio vulnificus and Vibrio parahaemolyticus abundances in oysters.

    Science.gov (United States)

    Jones, J L; Lydon, K A; Kinsey, T P; Friedman, B; Curtis, M; Schuster, R; Bowers, J C

    2017-07-17

    Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp) illnesses are typically acquired through the consumption of raw molluscan shellfish, particularly oysters. As Vibrio spp. are naturally-occurring bacteria, one means of mitigation of illness is achieved by limiting post-harvest growth. In this study, effects of ambient air storage, refrigeration, and icing of oysters on Vibrio spp. abundances were examined at two sites in Alabama (AL) [Dog River (DR) and Cedar Point (CP)] and one site in Delaware Bay, New Jersey (NJ). As the United States shellfish program recommendations include testing for total these organisms and gene targets, Vv and total (tlh) and pathogenic (tdh+ and trh+) Vp were enumerated from samples using MPN-real-time-PCR approaches. Mean Vv and Vp abundances in oysters from AL-DR were lowest in immediately iced samples (2.3 and -0.1 log MPN/g, respectively) and highest in the 5h ambient then refrigerated samples (3.4 and 0.5 log MPN/g, respectively). Similarly, in AL-CP Vv and Vp mean levels in oysters were lowest in immediately iced samples (3.6 and 1.2 log MPN/g, respectively) and highest in 5h ambient then refrigerated samples (5.1 and 3.2 log MPN/g, respectively). Mean levels of pathogenic Vp from AL sites were frequently below the limit of detection (ice resulted in lower Vibrio spp. levels in oysters, compared to those that were refrigerated post-harvest. These results suggest vibriosis risk can be mitigated by shorter storage times and more rapid cooling of oysters, providing data regulatory authorities can use to evaluate Vibrio spp. control plans. Published by Elsevier B.V.

  16. Distribution of putative virulence genes and antimicrobial drug resistance in Vibrio harveyi

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A.; Mendez, D.; Anto, C.

    -turn) and topologies and should be grouped into a common family, the 'metzincins'. FEBS Lett 331:134-140 16. Higgins CF (1992) ABC transporters: from microorganisms to man. Ann Rev Cell Biol 8:67- 113 17. Williams SG, Varcoe LT, Attridge SR, and Manning PA...) Lysogenic conversion by a filamentous phage encoding cholera toxin. Science 272:1910-1914 20. Fasano A, Fiorentini C, Donelli G, Uzzau S, Kaper JB, Margaretten K, Ding X, Guandalini S, Comstock L, and Goldblum SE (1995) Zonula occludens toxin...

  17. Vibrio fischeri metabolism: symbiosis and beyond.

    Science.gov (United States)

    Dunn, Anne K

    2012-01-01

    Vibrio fischeri is a bioluminescent, Gram-negative marine bacterium that can be found free living and in a mutualistic association with certain squids and fishes. Over the past decades, the study of V. fischeri has led to important discoveries about bioluminescence, quorum sensing, and the mechanisms that underlie beneficial host-microbe interactions. This chapter highlights what has been learned about metabolic pathways in V. fischeri, and how this information contributes to a broader understanding of the role of bacterial metabolism in host colonization by both beneficial and pathogenic bacteria, as well as in the growth and survival of free-living bacteria. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Genomic analysis of immune response against Vibrio cholerae hemolysin in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Surasri N Sahu

    Full Text Available Vibrio cholerae cytolysin (VCC is among the accessory V. cholerae virulence factors that may contribute to disease pathogenesis in humans. VCC, encoded by hlyA gene, belongs to the most common class of bacterial toxins, known as pore-forming toxins (PFTs. V. cholerae infects and kills Caenorhabditis elegans via cholerae toxin independent manner. VCC is required for the lethality, growth retardation and intestinal cell vacuolation during the infection. However, little is known about the host gene expression responses against VCC. To address this question we performed a microarray study in C. elegans exposed to V. cholerae strains with intact and deleted hlyA genes.Many of the VCC regulated genes identified, including C-type lectins, Prion-like (glutamine [Q]/asparagine [N]-rich-domain containing genes, genes regulated by insulin/IGF-1-mediated signaling (IIS pathway, were previously reported as mediators of innate immune response against other bacteria in C. elegans. Protective function of the subset of the genes up-regulated by VCC was confirmed using RNAi. By means of a machine learning algorithm called FastMEDUSA, we identified several putative VCC induced immune regulatory transcriptional factors and transcription factor binding motifs. Our results suggest that VCC is a major virulence factor, which induces a wide variety of immune response- related genes during V. cholerae infection in C. elegans.

  19. Cholera Toxin Production Induced upon Anaerobic Respiration is Suppressed by Glucose Fermentation in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Lee, Kang-Mu; Bari, Wasimul; Kim, Hwa Young; Kim, Hye Jin; Yoon, Sang Sun

    2016-03-01

    The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

  20. Disulfide bond formation and ToxR activity in Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Vera H I Fengler

    Full Text Available Virulence factor production in Vibrio cholerae is complex, with ToxRS being an important part of the regulatory cascade. Additionally, ToxR is the transcriptional regulator for the genes encoding the major outer membrane porins OmpU and OmpT. ToxR is a transmembrane protein and contains two cysteine residues in the periplasmic domain. This study addresses the influence of the thiol-disulfide oxidoreductase system DsbAB, ToxR cysteine residues and ToxR/ToxS interaction on ToxR activity. The results show that porin production correlates with ToxR intrachain disulfide bond formation, which depends on DsbAB. In contrast, formation of ToxR intrachain or interchain disulfide bonds is dispensable for virulence factor production and in vivo colonization. This study further reveals that in the absence of ToxS, ToxR interchain disulfide bond formation is facilitated, whereat cysteinyl dependent homo- and oligomerization of ToxR is suppressed if ToxS is coexpressed. In summary, new insights into gene regulation by ToxR are presented, demonstrating a mechanism by which ToxR activity is linked to a DsbAB dependent intrachain disulfide bond formation.

  1. Isolation and characterization of a N4-like lytic bacteriophage infecting Vibrio splendidus, a pathogen of fish and bivalves

    DEFF Research Database (Denmark)

    Katharios, Pantelis; Kalatzis, Panagiotis; Kokkari, Constantina

    2017-01-01

    A novel virulent bacteriophage, vB_VspP_pVa5, infecting a strain of Vibrio splendidus was isolated from a sea-cage aquaculture farm in Greece, and characterized using microbiological methods and genomic analysis. Bacteriophage vB_VspP_pVa5 is a N4-like podovirus with an icosahedral head measuring...... open reading frame–containing area was also identified. The absence of genes related to lysogeny along with the high efficacy observed during in vitro cell lysis trials, indicate that the vB_VspP_pVa5 is a potential candidate component in a bacteriophage cocktail suitable for the biological control...

  2. Exploring the Genomic Traits of Non-toxigenic Vibrio parahaemolyticus Strains Isolated in Southern Chile

    Directory of Open Access Journals (Sweden)

    Daniel Castillo

    2018-02-01

    Full Text Available Vibrio parahaemolyticus is the leading cause of seafood-borne gastroenteritis worldwide. As reported in other countries, after the rise and fall of the pandemic strain in Chile, other post-pandemic strains have been associated with clinical cases, including strains lacking the major toxins TDH and TRH. Since the presence or absence of tdh and trh genes has been used for diagnostic purposes and as a proxy of the virulence of V. parahaemolyticus isolates, the understanding of virulence in V. parahaemolyticus strains lacking toxins is essential to detect these strains present in water and marine products to avoid possible food-borne infection. In this study, we characterized the genome of four environmental and two clinical non-toxigenic strains (tdh-, trh-, and T3SS2-. Using whole-genome sequencing, phylogenetic, and comparative genome analysis, we identified the core and pan-genome of V. parahaemolyticus of strains of southern Chile. The phylogenetic tree based on the core genome showed low genetic diversity but the analysis of the pan-genome revealed that all strains harbored genomic islands carrying diverse virulence and fitness factors or prophage-like elements that encode toxins like Zot and RTX. Interestingly, the three strains carrying Zot-like toxin have a different sequence, although the alignment showed some conserved areas with the zot sequence found in V. cholerae. In addition, we identified an unexpected diversity in the genetic architecture of the T3SS1 gene cluster and the presence of the T3SS2 gene cluster in a non-pandemic environmental strain. Our study sheds light on the diversity of V. parahaemolyticus strains from the southern Pacific which increases our current knowledge regarding the global diversity of this organism.

  3. Complete genome sequence and comparative genomics of the golden pompano (Trachinotus ovatus pathogen, Vibrio harveyi strain QT520

    Directory of Open Access Journals (Sweden)

    Zhigang Tu

    2017-12-01

    Full Text Available Vibrio harveyi is a Gram-negative, halophilic bacterium that is an opportunistic pathogen of commercially farmed marine vertebrate species. To understand the pathogenicity of this species, the genome of V. harveyi QT520 was analyzed and compared to that of other strains. The results showed the genome of QT520 has two unique circular chromosomes and three endogenous plasmids, totaling 6,070,846 bp with a 45% GC content, 5,701 predicted ORFs, 134 tRNAs and 37 rRNAs. Common virulence factors, including ACF, IlpA, OmpU, Flagellin, Cya, Hemolysin and MARTX, were detected in the genome, which are likely responsible for the virulence of QT520. The results of genomes comparisons with strains ATCC 33843 (392 (MAV and ATCC 43516 showed that greater numbers genes associated with types I, II, III, IV and VI secretion systems were detected in QT520 than in other strains, suggesting that QT520 is a highly virulent strain. In addition, three plasmids were only observed in the complete genome sequence of strain QT520. In plasmid p1 of QT520, specific virulence factors (cyaB, hlyB and rtxA were identified, suggesting that the pathogenicity of this strain is plasmid-associated. Phylogenetic analysis of 12 complete Vibrio sp. genomes using ANI values, core genes and MLST revealed that QT520 was most closely related to ATCC 33843 (392 (MAV and ATCC 43516, suggesting that QT520 belongs to the species V. harveyi. This report is the first to describe the complete genome sequence of a V. harveyi strain isolated from an outbreak in a fish species in China. In addition, to the best of our knowledge, this report is the first to compare the V. harveyi genomes of several strains. The results of this study will expand our understanding of the genome, genetic characteristics, and virulence factors of V. harveyi, setting the stage for studies of pathogenesis, diagnostics, and disease prevention.

  4. Presence of CTX gene cluster in environmental non-O1/O139 Vibrio cholerae and its potential clinical significance

    Directory of Open Access Journals (Sweden)

    B Bakhshi

    2012-01-01

    Full Text Available Purpose: The aim of this study was to understand the epidemiological linkage of clinical and environmental isolates of Vibrio cholerae and to determine their genotypes and virulence genes content. Materials and Methods: A total of 60 V. cholerae strains obtained from clinical specimens (n = 40 and surface waters (n = 20 were subjected to genotyping using PFGE and determination of their virulence-associated gene clusters. Result: PCR analysis showed the presence of chromosomally located hly and RTX genetic elements in 100% and 90% of the environmental isolates, respectively. The phage-mediated genetic elements such as CTX, TLC and VPI were detected in 5% of the environmental isolates suggesting that the environmental isolates cannot acquire certain mobile gene clusters. A total of 4 and 18 pulsotypes were obtained among the clinical and environmental V. cholerae isolates, respectively. Non-pathogenic environmentally isolated V. cholerae constituted a distinct cluster with one single non-O1, non-O139 strain (EP6 carrying the virulence genes similar to the epidemic strains. This may suggest the possible potential of conversion of non-pathogenic to a pathogenic environmental strain. Conclusions: The emergence of a single environmental isolate in our study containing the pathogenicity genes amongst the diverse non-pathogenic environmental isolates needs to be further studied in the context of V. cholerae pathogenicity sero-coversion.

  5. Multiplex PCR for the detection and differentiation of Vibrio parahaemolyticus strains using the groEL, tdh and trh genes.

    Science.gov (United States)

    Hossain, Muhammad Tofazzal; Kim, Young-Ok; Kong, In-Soo

    2013-01-01

    Vibrio parahaemolyticus is a significant cause of human gastrointestinal disorders worldwide, transmitted primarily by ingestion of raw or undercooked contaminated seafood. In this study, a multiplex PCR assay for the detection and differentiation of V. parahaemolyticus strains was developed using primer sets for a species-specific marker, groEL, and two virulence markers, tdh and trh. Multiplex PCR conditions were standardised, and extracted genomic DNA of 70 V. parahaemolyticus strains was used for identification. The sensitivity and efficacy of this method were validated using artificially inoculated shellfish and seawater. The expected sizes of amplicons were 510 bp, 382 bp, and 171 bp for groEL, tdh and trh, respectively. PCR products were sufficiently different in size, and the detection limits of the multiplex PCR for groEL, tdh and trh were each 200 pg DNA. Specific detection and differentiation of virulent from non-virulent strains in shellfish homogenates and seawater was also possible after artificial inoculation with various V. parahaemolyticus strains. This newly developed multiplex PCR is a rapid assay for detection and differentiation of pathogenic V. parahaemolyticus strains, and could be used to prevent disease outbreaks and protect public health by helping the seafood industry maintain a safe shellfish supply. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Catechol Siderophore Transport by Vibrio cholerae.

    Science.gov (United States)

    Wyckoff, Elizabeth E; Allred, Benjamin E; Raymond, Kenneth N; Payne, Shelley M

    2015-09-01

    Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses the catechol siderophore vibriobactin and also uses siderophores secreted by other species, including enterobactin produced by Escherichia coli. E. coli secretes both canonical cyclic enterobactin and linear enterobactin derivatives likely derived from its cleavage by the enterobactin esterase Fes. We show here that V. cholerae does not use cyclic enterobactin but instead uses its linear derivatives. V. cholerae lacked both a receptor for efficient transport of cyclic enterobactin and enterobactin esterase to promote removal of iron from the ferrisiderophore complex. To further characterize the transport of catechol siderophores, we show that the linear enterobactin derivatives were transported into V. cholerae by either of the catechol siderophore receptors IrgA and VctA, which also transported the synthetic siderophore MECAM [1,3,5-N,N',N″-tris-(2,3-dihydroxybenzoyl)-triaminomethylbenzene]. Vibriobactin is transported via the additional catechol siderophore receptor ViuA, while the Vibrio fluvialis siderophore fluvibactin was transported by all three catechol receptors. ViuB, a putative V. cholerae siderophore-interacting protein (SIP), functionally substituted for the E. coli ferric reductase YqjH, which promotes the release of iron from the siderophore in the bacterial cytoplasm. In V. cholerae, ViuB was required for the use of vibriobactin but was not required for the use of MECAM, fluvibactin, ferrichrome, or the linear derivatives of enterobactin. This suggests the presence of another protein in V. cholerae capable of promoting the release of iron from these siderophores. Vibrio cholerae is a major human pathogen and also serves as a model for the Vibrionaceae, which include other serious human and fish pathogens. The ability of these species to persist and acquire essential

  7. Survival of Vibrio parahaemolyticus in cooked seafood at refrigeration temperatures.

    Science.gov (United States)

    Bradshaw, J G; Francis, D W; Twedt, R M

    1974-04-01

    The growth and survival of two strains of Vibrio parahaemolyticus isolated during food-borne gastroenteritis outbreaks in Japan and surface inoculated on cooked shrimp, shrimp with sauce, or cooked crab were tested at various refrigeration temperatures during a 48-h holding period. On cooked shrimp and crab, the vibrios grew well at 18.3 C, but their numbers declined gradually at 10 C and below. At 12.8 C, vibrios remained static for the most part. Thus, it appeared that 12.8 C was the borderline temperature for growth of the organism on cooked seafood. When cocktail sauce was added to surface-inoculated shrimp at a ratio of 2:1, the vibrio die-off rate was accelerated. In the shrimp and sauce few cells remained after 48 h, but in the sauce alone die-off was complete at 6 h.

  8. Opkomst van Vibrio infecties in brakwaterkweekvis : uit de ziekenboeg

    NARCIS (Netherlands)

    Haenen, O.L.M.; Engelsma, M.Y.

    2010-01-01

    De laatste paar jaar zijn er diverse Vibrio-soorten als ziekteverwekkende bacterie aangetoond in brak- en zoutwaterkweekvis. We gaan in dit artikel in op vibriose bij tong, tarbot, barramundi een zeebaars.

  9. Antibiotic Susceptibility Patterns and Plasmid Profile of Vibrio ...

    African Journals Online (AJOL)

    32.14%) samples of Vibrio cholerae isolates recovered from water samples from Elele Community. All isolates showed a multiple resistance patterns to 7 antibiotics namely amoxicillin, cotrimoxazole, nitrofurantoin, gentamicin, tetracycline, ...

  10. Isolation and molecular identification of Vibrio spp. by sequencing of ...

    African Journals Online (AJOL)

    Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 х104 CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 х104 CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9%) were Vibrio spp. Vibrio ...

  11. Inactivation of Vibrio anguillarum by attached and planktonic Roseobacter cells

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Melchiorsen, Jette; Porsby, Cisse Hedegaard

    2010-01-01

    The purpose of the present study was to investigate inhibition of Vibrio by Roseobacter in a combined liquid-surface system. Exposure of Vibrio anguillarum to surface-attached roseobacters (10e7 cfu/cm2) resulted in significant reduction or complete killing of the pathogen inoculated at 10e2 – 10...... cfu/ml. The effect was likely associated with production of tropodithietic acid (TDA), as a TDA-negative mutant did not affect survival or growth of V. anguillarum....

  12. Engineering Vibrio fischeri for Inducible Gene Expression.

    Science.gov (United States)

    Ondrey, Jakob M; Visick, Karen L

    2014-01-01

    The marine bacterium Vibrio fischeri serves as a model organism for a variety of natural phenomena, including symbiotic host colonization. The ease with which the V. fischeri genome can be manipulated contributes greatly to our ability to identify the factors involved in these phenomena. Here, we have adapted genetic tools for use in V. fischeri to promote our ability to conditionally control the expression of genes of interest. Specifically, we modified the commonly used mini-Tn5 transposon to contain an outward-facing, LacI-repressible/IPTG-inducible promoter, and inserted the lacI gene into the V. fischeri chromosome. Used together, these tools permit the identification and induction of genes that control specific phenotypes. To validate this approach, we identified IPTG-controllable motility mutants. We anticipate that the ability to randomly insert an inducible promoter into the genome of V. fischeri will advance our understanding of various aspects of the physiology of this microbe.

  13. Viscosity dictates metabolic activity of Vibrio ruber

    Science.gov (United States)

    Borić, Maja; Danevčič, Tjaša; Stopar, David

    2012-01-01

    Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase (GPD) increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment. PMID:22826705

  14. Morphological characterization and biocontrol effects of Vibrio vulnificus phages against Vibriosis in the shrimp aquaculture environment.

    Science.gov (United States)

    Srinivasan, Pappu; Ramasamy, Palaniappan

    2017-10-01

    The re-emerging field of phage therapy is the potential biocontrol agents for the transfer of virulence factor and to kill their bacterial hosts. In this study, the lytic Vibrio vulnificus phages were studied to provide a better understanding of phage-host interactions and development of phage therapy. Four new V. vulnificus phages were detected from shrimp aquaculture system, named VV1, VV2, VV3 and VV4. All lytic V. vulnificus phages are the Tectiviruses of the family Tectiviridae with typical double layered elongated icosahedral head and tailless morphology. Lytic V. vulnificus phages which infect other Vibrio isolates were further characterized by long term storage, enzymes treatment, organic solvents treatment, detergents treatment, pH stability, temperature stability, agar bioassay method and one-step growth experiment. The effects of chloroform, acetone, ethyl alcohol, methyl alcohol, ribonuclease (RNase), trypsin, protease, Triton-X100 treatments were not affected the growth of VV1, VV2, VV3 and VV4 phages. These phages (VV1-VV4) were inactivated completely with temperature (over 60 °C), pH (12), lysozyme and sodium dodecyl sulfate (SDS) treatment. One-step growth experiments indicated that the latent period was at 3 h and burst size was at 37 °C. Agar bioassay method indicated that the percentage of inhibition was 75% (VV1) and 70% (VV2, VV3 & VV4), respectively. SDS-PAGE analysis of all V. vulnificus phages had similar protein patterns with molecular weight masses of 260, 249, 204, 148, 63, 59, 22 and 15 kDa. Hence, it could be concluded that V. vulnificus phage had a broad lytic spectrum and potential biocontrol of luminous Vibriosis in the shrimp aquaculture system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Abundance and antibiotic susceptibility of Vibrio spp. isolated from microplastics

    Science.gov (United States)

    Laverty, A. L.; Darr, K.; Dobbs, F. C.

    2016-02-01

    In recent years, there has been a growing concern for `microplastics' (particles resistance profiles of Vibrio spp. found on them. We collected 22 microplastic pieces, paired seawater samples, and from them cultured 44 putative Vibrio spp. isolates, 18 of which were PCR-confirmed as V. parahaemolyticus and 3 as V. vulnificus. There were no PCR-confirmed V. cholerae isolates. We used the Kirby-Bauer disk diffusion susceptibility test to examine the isolates' response to six antibiotics: chloramphenicol (30μg), gentamicin (10μg), ampicillin (10μg), streptomycin (10μg), tetracycline (30μg), and rifampin (5μg). Vibrio isolates were susceptible to three or more of the six antibiotics tested and all were susceptible to tetracycline and chloramphenicol. There were no apparent differences between the antibiotic susceptibilities of vibrios isolated from microplastics compared to those from the water column. In every instance tested, vibrios on microplastics were enriched by at least two orders of magnitude compared to those from paired seawater samples. This study demonstrates that microplastic particles serve as a habitat for Vibrio species, in particular V. vulnificus and V. parahaemolyticus, confirming the conjecture of Zettler et al. (2013) that plastics may serve as a vector for these and other potentially pathogenic bacteria.

  16. Transcriptional regulation of opaR, qrr2-4 and aphA by the master quorum-sensing regulator OpaR in Vibrio parahaemolyticus.

    Directory of Open Access Journals (Sweden)

    Yiquan Zhang

    Full Text Available BACKGROUND: Vibrio parahaemolyticus is a leading cause of infectious diarrhea and enterogastritis via the fecal-oral route. V. harveyi is a pathogen of fishes and invertebrates, and has been used as a model for quorum sensing (QS studies. LuxR is the master QS regulator (MQSR of V. harveyi, and LuxR-dependent expression of its own gene, qrr2-4 and aphA have been established in V. harveyi. Molecular regulation of target genes by the V. parahaemolyticus MQSR OpaR is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: The bioinformatics analysis indicated that V. parahaemolyticus OpaR, V. harveyi LuxR, V. vulnificu SmcR, and V. alginolyticus ValR were extremely conserved, and that these four MQSRs appeared to recognize the same conserved cis-acting signals, which was represented by the consensus constructs manifesting as a position frequency matrix and as a 20 bp box, within their target promoters. The MQSR box-like sequences were found within the upstream DNA regions of opaR, qrr2-4 and aphA in V. parahaemolyticus, and the direct transcriptional regulation of these target genes by OpaR were further confirmed by multiple biochemical experiments including primer extension assay, gel mobility shift assay, and DNase I footprinting analysis. Translation and transcription starts, core promoter elements for sigma factor recognition, Shine-Dalgarno sequences for ribosome recognition, and OpaR-binding sites were determined for the five target genes of OpaR, which gave a structural map of the OpaR-dependent promoters. Further computational promoter analysis indicated the above regulatory circuits were shared by several other closely related Vibrios but with slight exceptions. CONCLUSIONS/SIGNIFICANCE: This study gave a comprehensive computational and characterization of the direct transcriptional regulation of five target genes, opaR, qrr2-4 and ahpA, by OpaR in V. parahaemolyticus. These characterized regulatory circuits were conserved in V. harveyi

  17. Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system.

    Science.gov (United States)

    Septer, Alecia N; Bose, Jeffrey L; Lipzen, Anna; Martin, Joel; Whistler, Cheryl; Stabb, Eric V

    2015-01-01

    The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence. © 2014 John Wiley & Sons Ltd.

  18. Competitive growth advantage of nontoxigenic mutants in the stationary phase in archival cultures of pathogenic Vibrio cholerae strains.

    Science.gov (United States)

    Paul, Kalidas; Ghosh, Amalendu; Sengupta, Nilanjan; Chowdhury, Rukhsana

    2004-09-01

    Spontaneous nontoxigenic mutants of highly pathogenic Vibrio cholerae O1 strains accumulate in large numbers during long-term storage of the cultures in agar stabs. In these mutants, production of the transcriptional regulator ToxR was reduced due to the presence of a mutation in the ribosome-binding site immediately upstream of the toxR open reading frame. Consequently, the ToxR-dependent virulence regulon was turned off, with concomitant reduction in the expression of cholera toxin and toxin-coregulated pilus. An intriguing feature of these mutants is that they have a competitive fitness advantage when grown in competition with the parent strains in stationary-phase cocultures which is independent of RpoS, the only locus known to be primarily associated with acquisition of a growth advantage phenotype in bacteria.

  19. Vibrio cholerae pathogen from the freshwater-cultured whiteleg shrimp Penaeus vannamei and control with Bdellovibrio bacteriovorus.

    Science.gov (United States)

    Cao, Haipeng; An, Jian; Zheng, Weidong; He, Shan

    2015-09-01

    Vibriosis has become a major global economic problem in freshwater-farmed whiteleg shrimp (Penaeus vannamei). The prevention and control of vibriosis are now priority research topics. In this study, a pathogenic strain (QH) was isolated from vibriosis-infected freshwater-farmed P. vannamei that resulted in leg yellowing and was identified as a Vibrio cholerae isolate through phylogenetic analysis and the API 32GN system. A phylogenetic tree that was constructed using the neighbor-joining method further confirmed the QH isolate as a V. cholerae strain. A virulent outer membrane protein (ompU) gene was found to be present in the QH isolate, which further confirmed its pathogenicity. In addition, Bdellovibrio bacteriovorus conferred significant protection against V. cholerae: B. bacteriovorus exhibited significant bacteriolytic effects on the V. cholerae pathogen, possessed a wide prey range that included Vibrio pathogens, and displayed a positive protective efficacy against experimental V. cholerae infection in P. vannamei. To the best of our knowledge, this is the first report of the control of shrimp pathogen V. cholerae with B. bacteriovorus. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Exception to the Rule: Genomic Characterization of Naturally Occurring Unusual Vibrio cholerae Strains with a Single Chromosome

    Directory of Open Access Journals (Sweden)

    Gary Xie

    2017-01-01

    Full Text Available The genetic make-up of most bacteria is encoded in a single chromosome while about 10% have more than one chromosome. Among these, Vibrio cholerae, with two chromosomes, has served as a model system to study various aspects of chromosome maintenance, mainly replication, and faithful partitioning of multipartite genomes. Here, we describe the genomic characterization of strains that are an exception to the two chromosome rules: naturally occurring single-chromosome V. cholerae. Whole genome sequence analyses of NSCV1 and NSCV2 (natural single-chromosome vibrio revealed that the Chr1 and Chr2 fusion junctions contain prophages, IS elements, and direct repeats, in addition to large-scale chromosomal rearrangements such as inversions, insertions, and long tandem repeats elsewhere in the chromosome compared to prototypical two chromosome V. cholerae genomes. Many of the known cholera virulence factors are absent. The two origins of replication and associated genes are generally intact with synonymous mutations in some genes, as are recA and mismatch repair (MMR genes dam, mutH, and mutL; MutS function is probably impaired in NSCV2. These strains are ideal tools for studying mechanistic aspects of maintenance of chromosomes with multiple origins and other rearrangements and the biological, functional, and evolutionary significance of multipartite genome architecture in general.

  1. Stumbling across the Same Phage: Comparative Genomics of Widespread Temperate Phages Infecting the Fish Pathogen Vibrio anguillarum

    Directory of Open Access Journals (Sweden)

    Panos G. Kalatzis

    2017-05-01

    Full Text Available Nineteen Vibrio anguillarum-specific temperate bacteriophages isolated across Europe and Chile from aquaculture and environmental sites were genome sequenced and analyzed for host range, morphology and life cycle characteristics. The phages were classified as Siphoviridae with genome sizes between 46,006 and 54,201 bp. All 19 phages showed high genetic similarity, and 13 phages were genetically identical. Apart from sporadically distributed single nucleotide polymorphisms (SNPs, genetic diversifications were located in three variable regions (VR1, VR2 and VR3 in six of the phage genomes. Identification of specific genes, such as N6-adenine methyltransferase and lambda like repressor, as well as the presence of a tRNAArg, suggested a both mutualistic and parasitic interaction between phages and hosts. During short term phage exposure experiments, 28% of a V. anguillarum host population was lysogenized by the temperate phages and a genomic analysis of a collection of 31 virulent V. anguillarum showed that the isolated phages were present as prophages in >50% of the strains covering large geographical distances. Further, phage sequences were widely distributed among CRISPR-Cas arrays of publicly available sequenced Vibrios. The observed distribution of these specific temperate Vibriophages across large geographical scales may be explained by efficient dispersal of phages and bacteria in the marine environment combined with a mutualistic interaction between temperate phages and their hosts which selects for co-existence rather than arms race dynamics.

  2. Vibrios associated with mortality in cultured plaice Pleuronectes platessa fry

    DEFF Research Database (Denmark)

    Pedersen, Karl; Austin, B.; Austin, D.A.

    1999-01-01

    is as yet uncertain. Selected isolates were tested for Virulence to salmon and turbot. When injected into juvenile salmonid fish, the recorded LD50 values were higher than 10(6), indicating that their virulence was relatively low. However, virulence seemed to deteriorate upon subculturing, and therefore...

  3. Differences in virulence of Naegleria fowleri.

    Science.gov (United States)

    De Jonckheere, J

    1979-10-01

    All pathogenic Naegleria fowleri isolated from the environment were highly virulent to mice when instilled intranasally. Axenic cultivation gradually decreased virulence of highly virulent strains. This decrease was most pronounced in environmental isolates and of minor importance in N. fowleri isolated from human cerebrospinal fluid. The low virulent strains obtained by continuous axenic cultivation appeared after clonation to consist of individuals with different virulence. Virulence could be enhanced in low virulent strains by brain passage and passages in Vero cell cultures, but could not be induced by these methods in nonvirulent strains isolated from the environment. Different mice strains showed different sensitivities to infection with pathogenic Naegleria. In addition, older mice were less sensitive than younger animals to low virulent strains.

  4. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Science.gov (United States)

    Acosta-Smith, Erika; Viveros-Jiménez, Karina; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Bolscher, Jan G. M.; Nazmi, Kamran; Flores-Villaseñor, Hector; Alapizco-Castro, Gerardo; de la Garza, Mireya; Martínez-Garcia, Jesús J.; Velazquez-Roman, Jorge; Leon-Sicairos, Nidia

    2018-01-01

    Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species. PMID:29375503

  5. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species.

    Science.gov (United States)

    Acosta-Smith, Erika; Viveros-Jiménez, Karina; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Bolscher, Jan G M; Nazmi, Kamran; Flores-Villaseñor, Hector; Alapizco-Castro, Gerardo; de la Garza, Mireya; Martínez-Garcia, Jesús J; Velazquez-Roman, Jorge; Leon-Sicairos, Nidia

    2017-01-01

    Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

  6. Anti-vibrio potentials of acetone and aqueous leaf extracts of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-vibrio potentials of acetone and aqueous leaf extracts of Ocimum gratissimum and determine its relevance in the treatment of vibrios infection. Methods: The agar-well diffusion method was used for screening the extracts for their anti-vibrio activity. Broth micro-dilution assay was used to ...

  7. Bacteriemia por Vibrio cholerae no-O1, no-O139 en un paciente en hemodiálisis crónica Non-O1, non-O139 Vibrio cholerae bacteremia in a chronic hemodialysis patient

    Directory of Open Access Journals (Sweden)

    Mariela S. Zárate

    2011-06-01

    Full Text Available Vibrio cholerae no-O1, no-O139 es un agente poco frecuente como causal de bacteriemias y no hay informes que documenten su presencia en pacientes en hemodiálisis crónica. Se describe el caso de una paciente en hemodiálisis crónica que presentó un cuadro de sepsis, por lo cual inició un tratamiento con vancomicina y ceftacidima. Al cabo de seis horas y media de incubación en el sistema BACT/ALERT de hemocultivo, se evidenció la presencia de bacilos curvos gram negativos, posteriormente identificados como Vibrio cholerae mediante pruebas bioquímicas convencionales y el uso de los kits API 20 NE y VITEK 2. La evaluación del serogrupo y de la presencia de factores de patogenicidad, realizada en el laboratorio de referencia, determinó que el microorganismo hallado pertenecía al serogrupo no-O1, no-O139. No se detectó la toxina de cólera, tampoco el factor de colonización ni la toxina termoestable. El aislamiento presentó sensibilidad frente a ampicilina, trimetoprima-sulfametoxazol, ciprofloxacina, tetraciclina, ceftacidima y cefotaxima por el método de difusión con discos y por VITEK 2. La paciente cumplió 14 días de tratamiento con ceftacidima endovenosa, con evolución favorable.Non-O1, and non-O139 Vibrio cholerae is an infrequent cause of bacteremia. There are no reports of such bacteremia in chronic hemodialysis patients. This work describes the case of a chronic hemodialysis patient that had an episode of septicemia associated with dialysis. Blood cultures were obtained and treatment was begun with vancomycin and ceftazidime. After 6.5 hours of incubation in the Bact/Alert system there is evidence of gram-negative curved bacilli that were identified as Vibrio cholerae by conventional biochemical tests, API 20 NE and the VITEK 2 system. This microorganism was sent to the reference laboratory for evaluation of serogroup and virulence factors and was identified as belonging to the non-O1 and non-O139 serogroup. The cholera

  8. Non-Cholera Vibrios: The Microbial Barometer of Climate Change.

    Science.gov (United States)

    Baker-Austin, Craig; Trinanes, Joaquin; Gonzalez-Escalona, Narjol; Martinez-Urtaza, Jaime

    2017-01-01

    There is a growing interest in the role of climate change in driving the spread of waterborne infectious diseases, such as those caused by bacterial pathogens. One particular group of pathogenic bacteria - vibrios - are a globally important cause of diseases in humans and aquatic animals. These Gram-negative bacteria, including the species Vibrio vulnificus, Vibrio parahaemolyticus and Vibrio cholerae, grow in warm, low-salinity waters, and their abundance in the natural environment mirrors ambient environmental temperatures. In a rapidly warming marine environment, there are greater numbers of human infections, and most notably outbreaks linked to extreme weather events such as heatwaves in temperate regions such as Northern Europe. Because the growth of pathogenic vibrios in the natural environment is largely dictated by temperature, we argue that this group of pathogens represents an important and tangible barometer of climate change in marine systems. We provide a number of specific examples of the impacts of climate change on this group of bacteria and their associated diseases, and discuss advanced strategies to improve our understanding of these emerging waterborne diseases through the integration of microbiological, genomic, epidemiological, climatic, and ocean sciences. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  9. Activation of Cholera Toxin Production by Anaerobic Respiration of Trimethylamine N-oxide in Vibrio cholerae*

    Science.gov (United States)

    Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-il; Yoon, Sang Sun

    2012-01-01

    Vibrio cholerae is a Gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2′,7′-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor. PMID:23019319

  10. Activation of cholera toxin production by anaerobic respiration of trimethylamine N-oxide in Vibrio cholerae.

    Science.gov (United States)

    Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-Il; Yoon, Sang Sun

    2012-11-16

    Vibrio cholerae is a gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2',7'-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor.

  11. Molecular Typing of Vibrio parahaemolyticus Strains Isolated from Mollusks in the North Adriatic Sea.

    Science.gov (United States)

    Rahman, Mohammad Shamsur; Carraro, Roberta; Cardazzo, Barbara; Carraro, Lisa; Meneguolo, Davide Boscolo; Martino, Maria Elena; Andreani, Nadia Andrea; Bordin, Paola; Mioni, Renzo; Barco, Lisa; Novelli, Enrico; Balzan, Stefania; Fasolato, Luca

    2017-08-01

    Vibrio parahaemolyticus is an emerging foodborne pathogen in the Mediterranean, usually associated with shellfish consumption. The increase in the number of outbreaks in Europe is primarily associated with the global warming of the ocean that has a great impact on the spread and genetic selection of waterborne pathogens. The primary role of Italy in Europe's mollusk production, together with the fact that cases of infections with V. parahaemolyticus are not always notified to the European community, highlighted the necessity of acquiring new information about the epidemiological involvement of shellfish products. The aim of the study was to provide useful insights into the first steps of the Risk Assessment associated with V. parahaemolyticus through the molecular characterization of isolates from commercialized mollusks. A total of 102 strains identified as V. parahaemolyticus were investigated as part of a larger sampling (1-year survey) from several shellfish species collected from the Venice lagoon and the North Adriatic sea. All strains were characterized by multilocus sequence typing and tested for the presence of virulence genes (trh and tdh). The study of sampling/environmental factors and epidemiological analyses was performed to describe the behaviors of the different genetic populations. The population structure analysis highlighted three genetic clusters that could be subject to temperature selection during cold (≤15°C) and warm (>16°C) seasons. Moreover, other factors, such as molluscan species (clams/mussels), probably played a role in the distribution of genetic clusters. Although few strains carried the virulence factors (n = 6 trh+), epidemiological links with clinical isolates and a local dissemination of some sequence types were underlined. This work provides a useful background on the genotype spread as a first step in the Hazard Identification in light of future climate changes.

  12. OpaR controls a network of downstream transcription factors in Vibrio parahaemolyticus BB22OP.

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    Alison Kernell Burke

    Full Text Available Vibrio parahaemolyticus is an emerging world-wide human pathogen that is associated with food-borne gastroenteritis when raw or undercooked seafood is consumed. Expression of virulence factors in this organism is modulated by the phenomenon known as quorum sensing, which permits differential gene regulation at low versus high cell density. The master regulator of quorum sensing in V. parahaemolyticus is OpaR. OpaR not only controls virulence factor gene expression, but also the colony and cellular morphology associated with growth on a surface and biofilm formation. Whole transcriptome Next Generation sequencing (RNA-Seq was utilized to determine the OpaR regulon by comparing strains BB22OP (opaR+, LM5312 and BB22TR (∆opaR1, LM5674. This work, using the published V. parahaemolyticus BB22OP genome sequence, confirms and expands upon a previous microarray analysis for these two strains that used an Affymetrix GeneChip designed from the closely related V. parahaemolyticus RIMD2210633 genome sequence. Overall there was excellent correlation between the microarray and RNA-Seq data. Eleven transcription factors under OpaR control were identified by both methods and further confirmed by quantitative reverse transcription PCR (qRT-PCR analysis. Nine of these transcription factors were demonstrated to be direct OpaR targets via in vitro electrophoretic mobility shift assays with purified hexahistidine-tagged OpaR. Identification of the direct and indirect targets of OpaR, including small RNAs, will enable the construction of a network map of regulatory interactions important for the switch between the nonpathogenic and pathogenic states.

  13. Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

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    Daniel Unterweger

    Full Text Available The type VI secretion system (T6SS mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria and a eukaryote (the social amoeba Dictyostelium discoideum. Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

  14. Prevalence and population structure of Vibrio vulnificus on fishes from the northern Gulf of Mexico.

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    Tao, Zhen; Larsen, Andrea M; Bullard, Stephen A; Wright, Anita C; Arias, Covadonga R

    2012-11-01

    The prevalence of Vibrio vulnificus on the external surfaces of fish from the northern Gulf of Mexico was determined in this study. A collection of 242 fish comprising 28 species was analyzed during the course of 12 sampling trips over a 16-month period. The prevalence of V. vulnificus was 37% but increased up to 69% in summer. A positive correlation was found between the percentages of V. vulnificus-positive fish and water temperatures, while salinity and V. vulnificus-positive fish prevalence were inversely correlated. A general lineal model (percent V. vulnificus-positive fish = 0.5930 - 0.02818 × salinity + 0.01406 × water temperature) was applied to best fit the data. Analysis of the population structure was carried out using 244 isolates recovered from fish. Ascription to 16S rRNA gene types indicated that 157 isolates were type A (62%), 72 (29%) were type B, and 22 (9%) were type AB. The percentage of type B isolates, considered to have greater virulence potential, was higher than that previously reported in oyster samples from the northern Gulf of Mexico. Amplified fragment length polymorphism (AFLP) was used to resolve the genetic diversity within the species. One hundred twenty-one unique AFLP profiles were found among all analyzed isolates, resulting in a calculated Simpson's index of diversity of 0.991. AFLP profiles were not grouped on the basis of collection date, fish species, temperature, or salinity, but isolates were clustered into two main groups that correlated precisely with 16S rRNA gene type. The population of V. vulnificus associated with fishes from the northern Gulf of Mexico is heterogeneous and includes strains of great virulence potential.

  15. Surface-attachment sequence in Vibrio Cholerae

    Science.gov (United States)

    Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard

    2013-03-01

    Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

  16. [Influence of aflatoxin on Vibrio fischeri luminescence].

    Science.gov (United States)

    Li, Xiang; Pan, Li; Wang, Bin

    2011-12-01

    In the present study, we aim to evaluate the inhibitory effect of aflatoxin on Vibrio fischeri luminescence. V. fischeri culture is treated with aflatoxin or the culture broth of aflatoxin-producing strains, and the luminescence intensity of V. fischeri is detected to analyze the influence of aflatoxin on V. fischeri. The logarithmic value of aflatoxin concentration and the decrease ratio of V. fischeri luminescence is in a linear relationship. Based on the regression equation between aflatoxin concentration and luminescence decrease of V. fischeri, the toxin-producing status of different microbes can be detected quickly and exactly: all of six tested Aspergillus flavus strains show toxigenicity to V. fischeri, and their toxin yield reached 14.94 mg/L - 46.45 mg/L (represented by aflatoxin concentration), while the tested Aspergillus oryzae shows no toxigenicity. The above data showed that the luminescence change of V. fischeri could exactly reflect the capability of various microbes to produce toxin (especially aflatoxin), which provided a new clue for rapid detection of aflatoxin in industrial and agricultural production and could be developed as a potential method for aflatoxin assay.

  17. Household Transmission of Vibrio cholerae in Bangladesh.

    Science.gov (United States)

    Sugimoto, Jonathan D; Koepke, Amanda A; Kenah, Eben E; Halloran, M Elizabeth; Chowdhury, Fahima; Khan, Ashraful I; LaRocque, Regina C; Yang, Yang; Ryan, Edward T; Qadri, Firdausi; Calderwood, Stephen B; Harris, Jason B; Longini, Ira M

    2014-11-01

    Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces) to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures. Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1) direct exposure within the household and 2) contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-valuelevels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered. Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of the transmissibility of endemic cholera within prospectively-followed members of households. The role of direct transmission must be considered when planning cholera control activities.

  18. Differential metabolic responses of clam Ruditapes philippinarum to Vibrio anguillarum and Vibrio splendidus challenges.

    Science.gov (United States)

    Liu, Xiaoli; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2013-12-01

    Clam Ruditapes philippinarum is one of the important marine aquaculture species in North China. However, pathogens can often cause diseases and lead to massive mortalities and economic losses of clam. In this work, we compared the metabolic responses induced by Vibrio anguillarum and Vibrio splendidus challenges towards hepatopancreas of clam using NMR-based metabolomics. Metabolic responses suggested that both V. anguillarum and V. splendidus induced disturbances in energy metabolism and osmotic regulation, oxidative and immune stresses with different mechanisms, as indicated by correspondingly differential metabolic biomarkers (e.g., amino acids, ATP, glucose, glycogen, taurine, betaine, choline and hypotaurine) and altered mRNA expression levels of related genes including ATP synthase, ATPase, glutathione peroxidase, heat shock protein 90, defensin and lysozyme. However, V. anguillarum caused more severe oxidative and immune stresses in clam hepatopancreas than V. splendidus. Our results indicated that metabolomics could be used to elucidate the biological effects of pathogens to the marine clam R. philippinarum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Vibrio fischeri flavohaemoglobin protects against nitric oxide during initiation of the squid-Vibrio symbiosis.

    Science.gov (United States)

    Wang, Yanling; Dunn, Anne K; Wilneff, Jacqueline; McFall-Ngai, Margaret J; Spiro, Stephen; Ruby, Edward G

    2010-11-01

    Nitric oxide (NO) is implicated in a wide range of biological processes, including innate immunity against pathogens, signal transduction and protection against oxidative stress. However, its possible roles in beneficial host-microbe associations are less well recognized. During the early stages of the squid-vibrio symbiosis, the bacterial symbiont Vibrio fischeri encounters host-derived NO, which has been hypothesized to serve as a specificity determinant. We demonstrate here that the flavohaemoglobin, Hmp, of V. fischeri protects against NO, both in culture and during colonization of the squid host. Transcriptional analyses indicate that hmp expression is highly responsive to NO, principally through the repressor, NsrR. Hmp protects V. fischeri from NO inhibition of aerobic respiration, and removes NO under both oxic and anoxic conditions. A Δhmp mutant of V. fischeri initiates squid colonization less effectively than wild type, but is rescued by the presence of an NO synthase inhibitor. The hmp promoter is activated during the initial stage of colonization, during which the Δhmp strain fails to form normal-sized aggregates of colonizing cells. Taken together, these results suggest that the sensing of host-derived NO by NsrR, and the subsequent removal of NO by Hmp, influence aggregate size and, thereby, V. fischeri colonization efficiency. © 2010 Blackwell Publishing Ltd.

  20. Role for cheR of Vibrio fischeri in the Vibrio-squid symbiosis.

    Science.gov (United States)

    Deloney-Marino, Cindy R; Visick, Karen L

    2012-01-01

    Upon hatching, the Hawaiian squid Euprymna scolopes is rapidly colonized by its symbiotic partner, the bioluminescent marine bacterium Vibrio fischeri . Vibrio fischeri cells present in the seawater enter the light organ of juvenile squid in a process that requires bacterial motility. In this study, we investigated the role chemotaxis may play in establishing this symbiotic colonization. Previously, we reported that V. fischeri migrates toward numerous attractants, including N-acetylneuraminic acid (NANA), a component of squid mucus. However, whether or not migration toward an attractant such as squid-derived NANA helps the bacterium to localize toward the light organ is unknown. When tested for the ability to colonize juvenile squid, a V. fischeri chemotaxis mutant defective for the methyltransferase CheR was outcompeted by the wild-type strain in co-inoculation experiments, even when the mutant was present in fourfold excess. Our results suggest that the ability to perform chemotaxis is an advantage during colonization, but not essential.

  1. Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

    Science.gov (United States)

    Dengo-Baloi, Liliana Candida; Semá-Baltazar, Cynthia Amino; Manhique, Lena Vania; Chitio, Jucunu Elias; Inguane, Dorteia Luísa; Langa, José Paulo

    2017-01-01

    Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin and (19/20) Cotrimoxazole, 83% (80

  2. Reclassification of the larval pathogen for marine bivalves Vibrio tubiashii subsp. europaeus as Vibrio europaeus sp. nov.

    Science.gov (United States)

    Dubert, Javier; Romalde, Jesús L; Spinard, Edward J; Nelson, David R; Gomez-Chiarri, Marta; Barja, Juan L

    2016-11-01

    The Orientalis clade has a relevant significance for bivalve aquaculture since it includes the pathogens Vibrio bivalvicida, Vibrio tubiashii subsp. tubiashii and Vibrio tubiashii subsp. europaeus. However, the previous taxonomic description of the subspecies of V. tubiashii shows some incongruities that should be emended. In the genomic age, the comparison between genome assemblies is the key to clarify the taxonomic position of both subspecies. With this purpose, we have tested the ability of multilocus sequence analysis based on eight housekeeping gene sequences (gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA and topA), different in silico genome-to-genome comparisons, chemotaxonomic features and phenotypic traits to reclassify the subspecies V. tubiashii subsp. europaeus within the Orientalis clade. This polyphasic approach clearly demonstrated that this subspecies is phylogenetically and phenotypically distinct from V. tubiashii and should be elevated to the rank of species as Vibrio europaeus sp. nov. This reclassification allows us to update the Orientalis clade (V. bivalvicida,V. brasiliensis, V. crosai, V. hepatarius, V. orientalis, V. sinaloensis, V. tubiashii and V. europaeus sp. nov.) and reconstruct a better phylogeny of the genus Vibrio. An emended description of V. tubiashii is provided. Finally, the proposed novel species is represented by emergent bivalve pathogens [type strain PP-638T (=CECT 8136T=DSM 27349T), PP2-843 and 07/118 T2] responsible for high mortalities in Spanish and French hatcheries.

  3. Insights into bacteriophage application in controlling Vibrio species

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    Vengadesh Letchumanan

    2016-07-01

    Full Text Available Bacterial infections from various organisms including Vibrio sp. pose a serious hazard to humans in many forms from clinical infection to affecting the yield of agriculture and aquaculture via infection of livestock. Vibrio sp. is one of the main foodborne pathogens causing human infection and is also a common cause of losses in the aquaculture industry. Prophylactic and therapeutic usage of antibiotics has become the mainstay of managing this problem, however this in turn led to the emergence of multidrug resistant strains of bacteria in the environment; which has raised awareness of the critical need for alternative non antibiotic based methods of preventing and treating bacterial infections. Bacteriophages - viruses that infect and result in the death of bacteria – are currently of great interest as a highly viable alternative to antibiotics. This article provides an insight into bacteriophage application in controlling Vibrio species as well underlining the advantages and drawbacks of phage therapy.

  4. Role of Shrimp Chitin in the Ecology of Toxigenic Vibrio cholerae and Cholera Transmission

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    Marzia eSultana

    2012-01-01

    Full Text Available Seasonal plankton blooms correlate with occurrence of cholera in Bangladesh, although the mechanism of how dormant Vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. In this study, laboratory microcosms prepared with estuarine Mathbaria water (MW samples supported active growth of toxigenic V. cholerae O1 up to seven weeks as opposed to six months when microcosms were supplemented with dehydrated shrimp chitin chips (CC as the single source of nutrient. Bacterial counting and detection of wbe and ctxA genes were done employing culture, Direct Fluorescent Antibody (DFA assay, and multiplex PCR (M-PCR methods. In MW microcosm, the aqueous phase became clear as the non-culturable cells settled, whereas the aqueous phase of the MW-CC microcosm became turbid from bacterial growth stimulated by chitin. Bacterial chitin degradation and biofilm formation proceeded from an initial steady state to a gradually declining bacterial culturable count. V. cholerae within the microenvironments of chitin and chitin-associated biofilms remained metabolically active even in a high acidic environment without losing either viability or virulence. It is concluded that the abundance of chitin that occurs during blooms plays an important role in the aquatic life cycle of V. cholerae and, ultimately, in the seasonal transmission of cholera.

  5. Role of Shrimp Chitin in the Ecology of Toxigenic Vibrio cholerae and Cholera Transmission.

    Science.gov (United States)

    Nahar, Shamsun; Sultana, Marzia; Naser, M Niamul; Nair, Gopinath B; Watanabe, Haruo; Ohnishi, Makoto; Yamamoto, Shouji; Endtz, Hubert; Cravioto, Alejandro; Sack, R Bradley; Hasan, Nur A; Sadique, Abdus; Huq, Anwar; Colwell, Rita R; Alam, Munirul

    2011-01-01

    Seasonal plankton blooms correlate with occurrence of cholera in Bangladesh, although the mechanism of how dormant Vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. In this study, laboratory microcosms prepared with estuarine Mathbaria water (MW) samples supported active growth of toxigenic V. cholerae O1 up to 7 weeks as opposed to 6 months when microcosms were supplemented with dehydrated shrimp chitin chips (CC) as the single source of nutrient. Bacterial counting and detection of wbe and ctxA genes were done employing culture, direct fluorescent antibody (DFA) assay, and multiplex-polymerase chain reaction methods. In MW microcosm, the aqueous phase became clear as the non-culturable cells settled, whereas the aqueous phase of the MW-CC microcosm became turbid from bacterial growth stimulated by chitin. Bacterial chitin degradation and biofilm formation proceeded from an initial steady state to a gradually declining bacterial culturable count. V. cholerae within the microenvironments of chitin and chitin-associated biofilms remained metabolically active even in a high acidic environment without losing either viability or virulence. It is concluded that the abundance of chitin that occurs during blooms plays an important role in the aquatic life cycle of V. cholerae and, ultimately, in the seasonal transmission of cholera.

  6. Characterization of Vibrio Parahaemolyticus isolated from oysters and mussels in São Paulo, Brazil

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    Martha Virginia Ribeiro Rojas

    2011-08-01

    Full Text Available Vibrio parahaemolyticus is a marine bacterium, responsible for gastroenteritis in humans. Most of the clinical isolates produce thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH encoded by tdh and trh genes respectively. In this study, twenty-three V. parahaemolyticus, previously isolated from oysters and mussels were analyzed by PCR using specific primers for the 16S rRNA and virulence genes (tdh, trh and tlh and for resistance to different classes of antibiotics and PFGE. Nineteen isolates were confirmed by PCR as V. parahaemolyticus. The tlh gene was present in 100% of isolates, the tdh gene was identified in two (10.5% isolates, whereas the gene trh was not detected. Each isolate was resistant to at least one of the nine antimicrobials tested. Additionally, all isolates possessed the blaTEM-116 gene. The presence of this gene in V. parahaemolyticus indicates the possibility of spreading this gene in the environment. Atypical strains of V. parahaemolyticus were also detected in this study.

  7. Visualization of coral host-pathogen interactions using a stable GFP-labeled Vibrio coralliilyticus strain

    Science.gov (United States)

    Pollock, F. Joseph; Krediet, Cory J.; Garren, Melissa; Stocker, Roman; Winn, Karina; Wilson, Bryan; Huete-Stauffer, Carla; Willis, Bette L.; Bourne, David G.

    2015-06-01

    The bacterium Vibrio coralliilyticus has been implicated as the causative agent of coral tissue loss diseases (collectively known as white syndromes) at sites across the Indo-Pacific and represents an emerging model pathogen for understanding the mechanisms linking bacterial infection and coral disease. In this study, we used a mini-Tn7 transposon delivery system to chromosomally label a strain of V. coralliilyticus isolated from a white syndrome disease lesion with a green fluorescent protein gene (GFP). We then tested the utility of this modified strain as a research tool for studies of coral host-pathogen interactions. A suite of biochemical assays and experimental infection trials in a range of model organisms confirmed that insertion of the GFP gene did not interfere with the labeled strain's virulence. Using epifluorescence video microscopy, the GFP-labeled strain could be reliably distinguished from non-labeled bacteria present in the coral holobiont, and the pathogen's interactions with the coral host could be visualized in real time. This study demonstrates that chromosomal GFP labeling is a useful technique for visualization and tracking of coral pathogens and provides a novel tool to investigate the role of V. coralliilyticus in coral disease pathogenesis.

  8. Successful small intestine colonization of adult mice by Vibrio cholerae requires ketamine anesthesia and accessory toxins.

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    Verena Olivier

    Full Text Available Vibrio cholerae colonizes the small intestine of adult C57BL/6 mice. In this study, the physical and genetic parameters that facilitate this colonization were investigated. Successful colonization was found to depend upon anesthesia with ketamine-xylazine and neutralization of stomach acid with sodium bicarbonate, but not streptomycin treatment. A variety of common mouse strains were colonized by O1, O139, and non-O1/non-O139 strains. All combinations of mutants in the genes for hemolysin, the multifunctional, autoprocessing RTX toxin (MARTX, and hemagglutinin/protease were assessed, and it was found that hemolysin and MARTX are each sufficient for colonization after a low dose infection. Overall, this study suggests that, after intragastric inoculation, V. cholerae encounters barriers to infection including an acidic environment and an immediate immune response that is circumvented by sodium bicarbonate and the anti-inflammatory effects of ketamine-xylazine. After initial adherence in the small intestine, the bacteria are subjected to additional clearance mechanisms that are evaded by the independent toxic action of hemolysin or MARTX. Once colonization is established, it is suggested that, in humans, these now persisting bacteria initiate synthesis of the major virulence factors to cause cholera disease. This adult mouse model of intestinal V. cholerae infection, now well-characterized and fully optimized, should serve as a valuable tool for studies of pathogenesis and testing vaccine efficacy.

  9. Signaling beyond Punching Holes: Modulation of Cellular Responses by Vibrio cholerae Cytolysin

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    Barkha Khilwani

    2015-08-01

    Full Text Available Pore-forming toxins (PFTs are a distinct class of membrane-damaging cytolytic proteins that contribute significantly towards the virulence processes employed by various pathogenic bacteria. Vibrio cholerae cytolysin (VCC is a prominent member of the beta-barrel PFT (beta-PFT family. It is secreted by most of the pathogenic strains of the intestinal pathogen V. cholerae. Owing to its potent membrane-damaging cell-killing activity, VCC is believed to play critical roles in V. cholerae pathogenesis, particularly in those strains that lack the cholera toxin. Large numbers of studies have explored the mechanistic basis of the cell-killing activity of VCC. Consistent with the beta-PFT mode of action, VCC has been shown to act on the target cells by forming transmembrane oligomeric beta-barrel pores, thereby leading to permeabilization of the target cell membranes. Apart from the pore-formation-induced direct cell-killing action, VCC exhibits the potential to initiate a plethora of signal transduction pathways that may lead to apoptosis, or may act to enhance the cell survival/activation responses, depending on the type of target cells. In this review, we will present a concise view of our current understanding regarding the multiple aspects of these cellular responses, and their underlying signaling mechanisms, evoked by VCC.

  10. Ocean acidification and host-pathogen interactions: blue mussels, Mytilus edulis, encountering Vibrio tubiashii.

    Science.gov (United States)

    Asplund, Maria E; Baden, Susanne P; Russ, Sarah; Ellis, Robert P; Gong, Ningping; Hernroth, Bodil E

    2014-04-01

    Ocean acidification (OA) can shift the ecological balance between interacting organisms. In this study, we have used a model system to illustrate the interaction between a calcifying host organism, the blue mussel Mytilus edulis and a common bivalve bacterial pathogen, Vibrio tubiashii, with organisms being exposed to a level of acidification projected to occur by the end of the 21st century. OA exposures of the mussels were carried out in relative long-term (4 months) and short-term (4 days) experiments. We found no effect of OA on the culturability of V. tubiashii, in broth or in seawater. OA inhibited mussel shell growth and impaired crystalline shell structures but did not appear to affect mussel immune parameters (i.e haemocyte counts and phagocytotic capacity). Despite no evident impact on host immunity or growth and virulence of the pathogen, V. tubiashii was clearly more successful in infecting mussels exposed to long-term OA compared to those maintained under ambient conditions. Moreover, OA exposed V. tubiashii increased their viability when exposed to haemocytes of OA-treated mussel. Our findings suggest that even though host organisms may have the capacity to cope with periods of OA, these conditions may alter the outcome of host-pathogen interactions, favouring the success of the latter. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome.

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    Brendan J O'Hara

    2017-06-01

    Full Text Available Vibrio cholerae-specific bacteriophages are common features of the microbial community during cholera infection in humans. Phages impose strong selective pressure that favors the expansion of phage-resistant strains over their vulnerable counterparts. The mechanisms allowing virulent V. cholerae strains to defend against the ubiquitous threat of predatory phages have not been established. Here, we show that V. cholerae PLEs (phage-inducible chromosomal island-like elements are widespread genomic islands dedicated to phage defense. Analysis of V. cholerae isolates spanning a 60-year collection period identified five unique PLEs. Remarkably, we found that all PLEs (regardless of geographic or temporal origin respond to infection by a myovirus called ICP1, the most prominent V. cholerae phage found in cholera patient stool samples from Bangladesh. We found that PLE activity reduces phage genome replication and accelerates cell lysis following ICP1 infection, killing infected host cells and preventing the production of progeny phage. PLEs are mobilized by ICP1 infection and can spread to neighboring cells such that protection from phage predation can be horizontally acquired. Our results reveal that PLEs are a persistent feature of the V. cholerae mobilome that are adapted to providing protection from a single predatory phage and advance our understanding of how phages influence pathogen evolution.

  12. A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome

    Science.gov (United States)

    O’Hara, Brendan J.

    2017-01-01

    Vibrio cholerae-specific bacteriophages are common features of the microbial community during cholera infection in humans. Phages impose strong selective pressure that favors the expansion of phage-resistant strains over their vulnerable counterparts. The mechanisms allowing virulent V. cholerae strains to defend against the ubiquitous threat of predatory phages have not been established. Here, we show that V. cholerae PLEs (phage-inducible chromosomal island-like elements) are widespread genomic islands dedicated to phage defense. Analysis of V. cholerae isolates spanning a 60-year collection period identified five unique PLEs. Remarkably, we found that all PLEs (regardless of geographic or temporal origin) respond to infection by a myovirus called ICP1, the most prominent V. cholerae phage found in cholera patient stool samples from Bangladesh. We found that PLE activity reduces phage genome replication and accelerates cell lysis following ICP1 infection, killing infected host cells and preventing the production of progeny phage. PLEs are mobilized by ICP1 infection and can spread to neighboring cells such that protection from phage predation can be horizontally acquired. Our results reveal that PLEs are a persistent feature of the V. cholerae mobilome that are adapted to providing protection from a single predatory phage and advance our understanding of how phages influence pathogen evolution. PMID:28594826

  13. Flavonoids from Piper delineatum modulate quorum-sensing-regulated phenotypes in Vibrio harveyi.

    Science.gov (United States)

    Martín-Rodríguez, Alberto J; Ticona, Juan C; Jiménez, Ignacio A; Flores, Ninoska; Fernández, José J; Bazzocchi, Isabel L

    2015-09-01

    Quorum sensing (QS), or bacterial cell-to-cell communication, is a key process for bacterial colonization of substrata through biofilm formation, infections, and production of virulence factors. In an ongoing investigation of bioactive secondary metabolites from Piper species, four new flavonoids (1-4), along with five known ones (5-9) were isolated from the leaves of Piper delineatum. Their stereostructures were established by spectroscopic and spectrometric methods, including 1D and 2D NMR experiments, and comparison with data reported in the literature. The compounds were screened for their ability to interfere with QS signaling in the bacterial model Vibrio harveyi. Four compounds from this series (2, 3, 6, and 7) exhibited remarkable activity in the micromolar range, being compounds 3 and 7 particularly attractive since they did not affect bacterial growth. The results suggest that these flavonoids disrupt QS-mediated bioluminescence by interaction with elements downstream LuxO in the QS circuit of V. harveyi, and also, they exhibited a strong dose-dependent inhibition of biofilm formation. The present findings shed light on the QS inhibition mechanisms of flavonoids, underlining their potential applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from seafoods in Lagos Lagoon Nigeria

    Directory of Open Access Journals (Sweden)

    Chigozie Oramadike

    2015-12-01

    Full Text Available In this study, a total of 90 seafood samples; croaker fish (Pseudotolithus senegalensis, shrimps (Penaeus notialis and blue crab (Callinectes sapidus collected from landing sites along the Lagos Lagoon in Nigeria were examined for the prevalence of Vibrio parahaemolyticus using both biochemical and molecular methods. Biochemical identification of the isolates was confirmed by Polymerase Chain Reaction (PCR. The presence of the virulence-associated tdh (thermostable direct haemolysin, trh1 (thermostable-related haemolysin and trh2 genes in the V. parahaemolyticus isolates was also detected by the PCR method. PCR products from the V.16S primers were sequenced. Antibiotics susceptibility of the isolates was also determined. About, eight isolates were presumptively identified as V. parahaemolyticus, PCR identified five and none of the isolates were positive for the genes tdh or trh. The five isolates sequenced were identified as different strains of V. parahaemolyticus. V. parahaemolyticus_RIMD_2210633 = 2MKSHa remained resistant to all antimicrobials tested. However, only V. parahaemolyticus_MP-2_AY911391 = TBSHy showed strong sensitivity to all the antimicrobials with ampicillin (minimum inhibitory concentration-4 μg/ml. In addition, the other three isolates showed sensitivity for Tetracycline, Ciprofloxacin, Gentamicin and Ceftazidime. Ampicillin resistance in most of the isolates suggests low efficiency of ampicillin in management of V. parahaemolyticus infection.

  15. Characterization of Aeromonas trota strains that cross-react with Vibrio cholerae O139 Bengal.

    Science.gov (United States)

    Albert, M J; Ansaruzzaman, M; Shimada, T; Rahman, A; Bhuiyan, N A; Nahar, S; Qadri, F; Islam, M S

    1995-12-01

    It has previously been shown that Vibrio cholerae O139 Bengal shares antigens with V. cholerae serogroups O22 and O155. We detected six surface water isolates of Aeromonas trota that agglutinated in polyclonal antisera to V. cholerae O139 and V. cholerae O22 but not in antiserum to V. cholerae O155. On the basis of agglutinin-absorption studies, the antigenic relationship between the cross-reacting bacteria were found to be in an a,b-a,c fashion, where a is the common antigenic epitope and b and c are unique epitopes. The antigen sharing between A. trota strains and V. cholerae O139 was confirmed in immunoblot studies. However, A. trota strains did not react with two monoclonal antibodies specific for V. cholerae O139 and, consequently, tested negative in the Bengal SMART rapid diagnostic test for V. cholerae O139 which uses one of the monoclonal antibodies. A polyclonal antiserum to a cross-reacting A. trota strain cross-protected infant mice against cholera on challenge with virulent V. cholerae O139. All A. trota strains were cytotoxic for HeLa cells, positive for adherence to HEp-2 cells, and weakly invasive for HEp-2 cells; one strain was heat-stable toxin positive in the suckling mouse assay; however, all strains were negative for cholera toxin-like enterotoxin. Studies on bacteria that share somatic antigen with V. cholerae O139 may shed further light on the genesis of V. cholerae O139.

  16. Vibrio parahaemolyticus a causative bacterium for tail rot disease in ornamental fish, Amphiprion sebae

    Directory of Open Access Journals (Sweden)

    Thangapandi Marudhupandi

    2017-11-01

    Full Text Available The present study was performed to identify the tail rot disease causing bacterium in marine ornamental fish, Amphiprion sebae. Bacteria were isolated from the infected immune organs and tail region of A. sebae. Five different bacterial isolates (S1-S5 with different shape, size and colour were chosen for the infection study. The isolated strains were individually challenged with A. sebae at a constant dose of 1 × 107 CFU/fish. The virulent strain was found to be S-3, which showed maximum reproducing ability in A. sebae by causing typical tail rot disease and mortality. Furthermore, S-3 strain was identified as Vibrio parahaemolyticus by 16S rRNA gene sequencing (KF738005, biochemical analysis and amplification of tox R gene. Subsequently, extracellular products (ECPs of V. parahaemolyticus were prepared by cellophane overlay method. The LD50 value of V. parahaemolyticus and its ECPS were found to be 1 × 105 CFU and 5 μg/fish. The histology results revealed that V. parahaemolyticus and its ECPS are the major cause of tail rot disease in A. sebae.

  17. Expression and processing of Vibrio anguillarum zinc-metalloprotease in Escherichia coli.

    Science.gov (United States)

    Zhang, Fengli; Chen, Jixiang; Chi, Zhenming; Wu, Long-Fei

    2006-07-01

    The extracellular zinc-metalloprotease of Vibrio anguillarum is a secreted virulence factor. It is synthesized from the empA gene as a 611-residue preproprotease and processed to the active mature protease (EmpA) with concomitant secretion via the type II secretion pathway. Active EmpA has been found only in the V. anguillarum culture supernatant and the process of the activation seems to vary depending on strains analyzed. To better understand the mechanism of EmpA export and processing, the empA gene was cloned and expressed in Escherichia coli strains. Expression of empA did not have toxic effect on bacterial growth. Rupturing E. coli TOP10 cells by heating in gel-loading buffer resulted in activation of EmpA and severe proteolysis of the samples. In contrast, the same treatment of the E. coli MC4100A strain did not lead to the general proteolysis. In this strain, EmpA was exported into the periplasm via the Sec pathway. The periplasmic EmpA was detected in two active conformations. Therefore, in E. coli processing of EmpA precursor to an active enzyme did not require secretion to the media and the help of other V. anguillarum protein. Like in V. anguillarum, heterologous expression of empA in E. coli showed strain-specific activation process.

  18. Reclassification of Vibrio fischeri, Vibrio logei, Vibrio salmonicida and Vibrio wodanis as Aliivibrio fischeri gen. nov., comb. nov., Aliivibrio logei comb. nov., Aliivibrio salmonicida comb. nov. and Aliivibrio wodanis comb. nov.

    Science.gov (United States)

    Urbanczyk, Henryk; Ast, Jennifer C; Higgins, Melissa J; Carson, Jeremy; Dunlap, Paul V

    2007-12-01

    Four closely related species, Vibrio fischeri, Vibrio logei, Vibrio salmonicida and Vibrio wodanis, form a clade within the family Vibrionaceae; the taxonomic status and phylogenetic position of this clade have remained ambiguous for many years. To resolve this ambiguity, we tested these species against other species of the Vibrionaceae for phylogenetic and phenotypic differences. Sequence identities for the 16S rRNA gene were > or =97.4 % among members of the V. fischeri group, but were Vibrio, with which they overlap in G+C content, and Enterovibrio, Grimontia and Salinivibrio, with which they do not overlap in G+C content). Combined analysis of the recA, rpoA, pyrH, gyrB and 16S rRNA gene sequences revealed that the species of the V. fischeri group form a tightly clustered clade, distinct from these other genera. Furthermore, phenotypic traits differentiated the V. fischeri group from other genera of the Vibrionaceae, and a panel of 13 biochemical tests discriminated members of the V. fischeri group from type strains of Photobacterium and Vibrio. These results indicate that the four species of the V. fischeri group represent a lineage within the Vibrionaceae that is distinct from other genera. We therefore propose their reclassification in a new genus, Aliivibrio gen. nov. Aliivibrio is composed of four species: Aliivibrio fischeri comb. nov. (the type species) (type strain ATCC 7744(T) =CAIM 329(T) =CCUG 13450(T) =CIP 103206(T) =DSM 507(T) =LMG 4414(T) =NCIMB 1281(T)), Aliivibrio logei comb. nov. (type strain ATCC 29985(T) =CCUG 20283(T) =CIP 104991(T) =NCIMB 2252(T)), Aliivibrio salmonicida comb. nov. (type strain ATCC 43839(T) =CIP 103166(T) =LMG 14010(T) =NCIMB 2262(T)) and Aliivibrio wodanis comb. nov. (type strain ATCC BAA-104(T) =NCIMB 13582(T) =LMG 24053(T)).

  19. Long-term effects of ocean warming on vibrios

    Science.gov (United States)

    Pruzzo, C.; Pezzati, E.; Brettar, I.; Reid, P. C.; Colwell, R.; Höfle, M. G.; vezzulli, L.

    2012-12-01

    Vibrios are a major source of human disease, play an important role in the ecology and health of marine animals and are regarded as an abundant fraction of culturable bacteria of the ocean. There has been a considerable global effort to reduce the risk of Vibrio infections and yet in most countries both human and non-human illnesses associated with these bacteria are increasing. The cause of this increase is not known, but since vibrios are strongly thermodependant there is good reason to believe that global warming may have contributed. To investigate this possibility we examined historical samples from the Continuous Plankton Recorder (CPR) archive using advanced molecular analysis and pyrosequencing. For the first time we were able to recover environmental DNA from CPR samples that had been stored for up to ~50 years in a formalin-fixed format, which is suitable for molecular analyses of the associated prokaryotic community. To overcome the problem of DNA degradation due to the sample age and storage in formalin we develop an unbiased index of abundance for Vibrio quantification in CPR samples termed a 'relative Vibrio Abundance Index' (VAI). VAI is defined as the ratio of Vibrio spp. cells to total bacterial cells assessed by Real-Time PCR using genus-specific and universal primers, respectively, producing small amplicons of similar size (~100bp). We assessed VAI index on 55 samples (each representing 10 nautical miles tow equal to 3 m3 of filtered sewater) collected in August by the CPR survey in the North Sea from off the Rhine and Humber estuaries between 1961 to 2005 showing that the genus Vibrio has increased in prevalence in the last 44 years and that this increase is correlated significantly, during the same period, with warming sea surface temperature. In addition, by applying deep sequencing analysis of a subset of these samples we provide evidence that bacteria belonging to the genus Vibrio, including the human pathogen V. cholerae, not only increased

  20. Development and Validation of a Novel Real-time Assay for the Detection and Quantification of Vibrio cholerae

    DEFF Research Database (Denmark)

    Rashid, Ridwan Bin; Ferdous, Jannataul; Tulsiani, Suhella

    2017-01-01

    Vibrio cholerae O1 and O139 has been known for its ability to cause epidemics. These strains produce cholera toxin which is the main cause of secretory diarrhea. V. cholerae non-O1 and non-O139 strains are also capable of causing gastroenteritis as well as septicemia and peritonitis. It has been...... proven that virulence factors such as T6SS, hapA, rtxA, and hlyA are present in almost all V. cholerae strains. It is imperative that viable but non-culturable cells of V. cholerae are also detected since they are also known to cause diarrhea. Thus, the aim of this study was to develop an assay...... that detects all V. cholerae regardless of their serotype, culturable state, and virulence genes present, by targeting the species specific conserved ompW sequence. The developed assay meets these goals with 100% specificity and is capable of detecting as low as 5.46 copy number of V. cholerae. Detection...

  1. Arabinose induces pellicle formation by Vibrio fischeri.

    Science.gov (United States)

    Visick, Karen L; Quirke, Kevin P; McEwen, Sheila M

    2013-03-01

    Biofilms are multicellular communities of bacteria attached to a surface and embedded in a protective matrix. In many cases, the signals that induce biofilm formation are unknown. Here, we report that biofilm formation by the marine bacterium Vibrio fischeri can be induced by the addition of arabinose to LBS (Luria-Bertani-salt), a tryptone-based medium. Growth of cells in the presence of 0.2% arabinose, but not other sugars, induced the production of a pellicle at the air/liquid interfaces of static cultures. V. fischeri failed to grow on arabinose as the sole carbon source, suggesting that pellicle production did not occur as a result of increased growth, but experiments using the acid/base indicator phenol red suggested that V. fischeri may partially metabolize arabinose. Pellicle production was independent of the syp polysaccharide locus but was altered upon disruption of the bcs cellulose locus. Through a screen for mutants defective for pellicle production, we found that loss of motility disrupted the formation of the arabinose-induced pellicle. Among the ∼20 mutants that retained motility were strains with insertions in a putative msh pilus locus and a strain with a defect in yidK, which is involved in galactose catabolism. Mutants with the msh gene disrupted grew poorly in the presence of arabinose, while the yidK mutant appeared to be "blind" to the presence of arabinose. Finally, arabinose impaired symbiotic colonization by V. fischeri. This work thus identifies a novel signal and new pathways involved in control of biofilm formation by V. fischeri.

  2. Development of a More Sensitive and Specific Chromogenic Agar Medium for the Detection of Vibrio parahaemolyticus and Other Vibrio Species.

    Science.gov (United States)

    Yeung, Marie; Thorsen, Trevor

    2016-11-08

    Foodborne infections in the US caused by Vibrio species have shown an upward trend. In the genus Vibrio, V. parahaemolyticus is responsible for the majority of Vibrio-associated infections. Thus, accurate differentiation among Vibrio spp. and detection of V. parahaemolyticus is critically important to ensure the safety of our food supply. Although molecular techniques are increasingly common, culture-depending methods are still routinely done and they are considered standard methods in certain circumstances. Hence, a novel chromogenic agar medium was tested with the goal of providing a better method for isolation and differentiation of clinically relevant Vibrio spp. The protocol compared the sensitivity, specificity and detection limit for the detection of V. parahaemolyticus between the new chromogenic medium and a conventional medium. Various V. parahaemolyticus strains (n=22) representing diverse serotypes and source of origins were used. They were previously identified by Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), and further verified in our laboratory by tlh-PCR. In at least four separate trials, these strains were inoculated on the chromogenic agar and thiosulfate-citrate-bile salts-sucrose (TCBS) agar, which is the recommended medium for culturing this species, followed by incubation at 35-37 °C for 24-96 hr. Three V. parahaemolyticus strains (13.6%) did not grow optimally on TCBS, nonetheless exhibited green colonies if there was growth. Two strains (9.1%) did not yield the expected cyan colonies on the chromogenic agar. Non-V. parahaemolyticus strains (n=32) were also tested to determine the specificity of the chromogenic agar. Among these strains, 31 did not grow or exhibited other colony morphologies. The mean recovery of V. parahaemolyticus on the chromogenic agar was ~96.4% relative to tryptic soy agar supplemented with 2% NaCl. In conclusion, the new chromogenic agar is an effective medium to detect V

  3. Campylobacter virulence and survival factors.

    Science.gov (United States)

    Bolton, Declan J

    2015-06-01

    Despite over 30 years of research, campylobacteriosis is the most prevalent foodborne bacterial infection in many countries including in the European Union and the United States of America. However, relatively little is known about the virulence factors in Campylobacter or how an apparently fragile organism can survive in the food chain, often with enhanced pathogenicity. This review collates information on the virulence and survival determinants including motility, chemotaxis, adhesion, invasion, multidrug resistance, bile resistance and stress response factors. It discusses their function in transition through the food processing environment and human infection. In doing so it provides a fundamental understanding of Campylobacter, critical for improved diagnosis, surveillance and control. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The light organ symbiont Vibrio fischeri possesses a homolog of the Vibrio cholerae transmembrane transcriptional activator ToxR.

    OpenAIRE

    Reich, K A; Schoolnik, G K

    1994-01-01

    A cross-hybridizing DNA fragment to Vibrio cholerae toxR was cloned from the nonpathogenic light organ symbiont Vibrio fischeri, and three proteins homologous to V. cholerae ToxR, ToxS, and HtpG were deduced from its DNA sequence. V. fischeri ToxR was found to activate a V. cholerae ToxR-regulated promoter, and an antiserum raised against the amino-terminal domain of V. cholerae ToxR cross-reacts V. fischeri ToxR.

  5. Comparative evaluation of the antimicrobial activity of Citrullus ...

    African Journals Online (AJOL)

    ... Salmonella typhimurium, Vibrio parahaemolyticus and Vibrio alginolyticus) and gram-positive (Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes and Micrococcus luteus) bacteria and various Candida spp. (Candida glabrata, Candida albicans, Candida parapsilosis and ...

  6. Localization of immunodominant linear B-cell epitopes of Vibrio ...

    African Journals Online (AJOL)

    Outer membrane protein U (OmpU), an adhesion protein of Vibrio mimicus, is a good antigen, but its epitopes are still unclear. In order to locate the epitopes of OmpU protein, epitope prediction was performed using the amino acid sequence of OmpU protein of V. mimicus HX4 strain that was isolated from the diseased ...

  7. Vibrio vulnificus-infektioner i Danmark sommeren 1994

    DEFF Research Database (Denmark)

    Bruun, Brita Grønbech; Frimodt-Møller, N; Dalsgaard, A.

    1996-01-01

    The clinical manifestations and epidemiological data of 11 patients infected with Vibrio vulnificus found in Denmark during the unusually warm summer of 1994 are reported. All patients had been exposed to seawater prior to illness, but none had consumed seafood. Nine patients, including four...

  8. Genome sequence of the human pathogen Vibrio cholerae Amazonia.

    NARCIS (Netherlands)

    Thompson, C.C.; Marin, M.A.; Dias, G.M.; Dutilh, B.E.; Edwards, R.A.; Iida, T.; Thompson, F.L.; Vicente, A.C.

    2011-01-01

    Vibrio cholerae O1 Amazonia is a pathogen that was isolated from cholera-like diarrhea cases in at least two countries, Brazil and Ghana. Based on multilocus sequence analysis, this lineage belongs to a distinct profile compared to strains from El Tor and classical biotypes. The genomic analysis

  9. Molecular analysis of the emergence of pandemic Vibrio parahaemolyticus

    DEFF Research Database (Denmark)

    Boyd, EF; Cohen, AL; Naughton, LM

    2008-01-01

    Background Vibrio parahaemolyticus is abundant in the aquatic environment particularly in warmer waters and is the leading cause of seafood borne gastroenteritis worldwide. Prior to 1995, numerous V. parahaemolyticus serogroups were associated with disease, however, in that year an O3:K6 serogroup...

  10. Detection of quorum sensing molecules from Vibrio harveyi and use ...

    African Journals Online (AJOL)

    This paper explores the extraction and detection processes of quorum sensing molecules such as N-aceyl homoserine lactone compounds (AHL) from marine Vibrio harveyi. The spent culture of V. harveyi was solvent partitioned for AHL, rotary evaporated and re-suspended in 50% acetonitrile then detected with reporter ...

  11. Survival of Vibrio cholerae in industrially polluted water, with ...

    African Journals Online (AJOL)

    containing industrial effluents. The effect of iron as well as pH on the survival of Vibrio cholerae (non-O1, El Tor and classical strains) in water samples from 12 points, where selected industrial effluents were discharged into rivers, was studied.

  12. Detection and confirmation of toxigenic Vibrio cholerae O1 in ...

    African Journals Online (AJOL)

    Epidemic cholera caused by toxigenic Vibrio cholerae O1 is a major health problem in several developing countries. Traditional methods for identifying V. cholerae involve cultural, biochemical and immunological assays which are cumbersome and often take several days to complete. In the present study, a direct cell ...

  13. Vibrio Cholerae 01 Infections In Jos, Nigeria | Opajobi | African ...

    African Journals Online (AJOL)

    A study to determine the prevalence of Vibrio cholerae 01 in stool sample submitted for routine examination of enteric pathogens, as well as identify the serotypes and antibiogram of the isolates to commonly used antibiotics was undertaken. The survey involved the examination of 774 (763 stool and 11 rectal swabs) ...

  14. Ion-swimming speed variation of Vibrio cholerae cells

    Indian Academy of Sciences (India)

    In the present work we report the variation in swimming speed of Vibrio cholerae with respect to the change in concentration of sodium ions in the medium. We have also studied the variation in swimming speed with respect to temperature. We find that the swimming speed initially shows a linear increase with the increase of ...

  15. Salmonella and Vibrio cholerae in Nile perch ( Lates niloticus ...

    African Journals Online (AJOL)

    The Nile perch (Lates niloticus) industry in East Africa has suffered severe economic losses in the last few years due to failure to comply with the microbiological standards of European Union (E.U). Fresh and frozen products have been suspected to be contaminated with Salmonella and Vibrio cholerae. This has led to a ...

  16. Detection and confirmation of toxigenic Vibrio cholerae O1 in ...

    African Journals Online (AJOL)

    2013-08-20

    Aug 20, 2013 ... Epidemic cholera caused by toxigenic Vibrio cholerae O1 is a major health problem in several developing countries. Traditional methods for identifying V. cholerae involve cultural, biochemical and immunological assays which are cumber- some and often take several days to complete. In the present study, ...

  17. antimicrobial susceptibility pattern of vibrio cholerae 01 strains

    African Journals Online (AJOL)

    hi-tech

    East African Medical Journal Vol. 77 No. 7 July 2000. ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF VIBRIO CHOLERAE 01 STRAINS DURING TWO CHOLERA OUTBREAKS IN DAR ES SALAAM,. TANZANIA. W.K. Urassa, MD, MSc, MMed, Lecturer, Department of Microbiology and Immunology, Muhimbili University ...

  18. Prevalence of Vibrio cholerae in rivers of Mpumalanga province ...

    African Journals Online (AJOL)

    Cholera is a life-threatening diarrhoeal disease, which mainly affects inhabitants of developing countries due to poor socio-economic conditions and lack of access to potable water and sanitation. Toxigenic Vibrio cholerae are the aetiological agents of cholera. These bacteria are autochthonous to aquatic environments, ...

  19. Vibriophages and Their Interactions with the Fish Pathogen Vibrio anguillarum

    DEFF Research Database (Denmark)

    Tan, Demeng; Gram, Lone; Middelboe, Mathias

    2014-01-01

    Vibrio anguillarum is an important pathogen in aquaculture, responsible for the disease vibriosis in many fish and invertebrate species. Disease control by antibiotics is a concern due to potential development and spread of antibiotic resistance. The use of bacteriophages to control the pathogen...

  20. Evaluation of in vitro Vibrio static activity of Shewanella algae ...

    African Journals Online (AJOL)

    conventional methods followed by Biolog microlog software. Since production of antagonistic agents rely on cultural conditions, antagonistic ability of candidate probioic against the mentioned Vibrios was assessed using Response Surface Methodology, with central composite design in which four independents variables ...

  1. Pseudomonas piscicida kills vibrios by two distinct mechanisms

    Science.gov (United States)

    Pseudoalteromonas piscicida is a naturally-occurring marine bacterium which kills competing bacteria, including vibrios. In studies by Richards et al. (AEM00175-17), three strains of P. piscicida were isolated and characterized. Strains secreted proteolytic enzymes which likely killed competing or...

  2. Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

    Science.gov (United States)

    Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

    2014-01-01

    As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

  3. Cholera toxin production during anaerobic trimethylamine N-oxide respiration is mediated by stringent response in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M; Lee, Kang-Mu; Yoon, Sang Sun

    2014-05-09

    As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae.

  4. Household Transmission of Vibrio cholerae in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jonathan D Sugimoto

    2014-11-01

    Full Text Available Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures.Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1 direct exposure within the household and 2 contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001 occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%-22.8% risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length. The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%-8.0%. The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%-16.6% and 8.2% (2.1%-27.1% through direct exposure, and 3.4% (1.7%-6.7% and 2.0% (0.5%-7.3% through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered.Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of

  5. Presence of T3SS2β genes in trh⁺ Vibrio parahaemolyticus isolated from seafood harvested along Mangalore coast, India.

    Science.gov (United States)

    Kumar, B K; Deekshit, V K; Rai, P; Shekar, M; Karunasagar, I; Karunasagar, I

    2014-05-01

    Vibrio parahaemolyticus is a seafood-borne pathogen autochthonous to the marine and estuarine ecosystem, responsible for gastroenteritis when contaminated raw seafood is consumed. The pathogenicity has been associated with thermostable direct haemolysin (TDH) and TDH-related haemolysin (TRH). Of late, the presence of T3SS2α and T3SS2β gene clusters has been well documented in clinical isolates of Vibrio parahaemolyticus and known to play an essential role in pathogenesis. However, reports on the presence of T3SSβ genes in V. parahaemolyticus isolated from the seafood and/or environmental samples are scanty. In this study, we have identified and analysed the distribution of the T3SS2β genes in V. parahaemolyticus isolated from seafood harvested along southwest coast of India. Results showed that T3SS2β genes are solely associated with trh⁺ and tdh⁺ /trh⁺ strains of V. parahaemolyticus. Reverse transcriptase PCR (RT-PCR) showed that the T3SS2β genes identified in trh⁺ V. parahaemolyticus were transcriptionally active. To our knowledge, this study appears to be the first description on the presence of T3SS2β-positive V. parahaemolyticus isolated from seafood in India. The study of T3SS2 along with other virulence factors will help in better understanding of the risk of seafood-borne illness due to V. parahaemolyticus. T3SSs (α or β) are the important virulence factors of Vibrio parahaemolyticus that contribute to their pathogenicity in humans. This study demonstrated the presence of T3SS2β genes in V. parahaemolyticus isolated from the seafood harvested along Mangalore coast. RT-PCR showed that the T3SS2β genes identified in seafood isolates of V. parahaemolyticus were found to be functional. To the best of our knowledge, this is the first description of T3SS2β genes in trh⁺ V. parahaemolyticus isolated from seafood in India. The presence of T3SS2 along with other virulence factors such as TDH and/or TRH highlights a potential health risk for

  6. Vibrio fischeri Outer Membrane Protein OmpU Plays a Role in Normal Symbiotic Colonization

    Science.gov (United States)

    Aeckersberg, F.; Lupp, C.; Feliciano, B.; Ruby, E. G.

    2001-01-01

    The nascent light-emitting organ of newly hatched juveniles of the Hawaiian sepiolid squid Euprymna scolopes is specifically colonized by cells of Vibrio fischeri that are obtained from the ambient seawater. The mechanisms that promote this specific, cooperative colonization are likely to require a number of bacterial and host-derived factors and activities, only some of which have been described to date. A characteristic of many host-pathogen associations is the presence of bacterial mechanisms that allow attachment to specific tissues. These mechanisms have been well characterized and often involve bacterial fimbriae or outer membrane proteins (OMPs) that act as adhesins, the expression of which has been linked to virulence regulators such as ToxR in Vibrio cholerae. Analogous or even homologous mechanisms are probably operative in the initiation and persistence of cooperative bacterial associations, although considerably less is known about them. We report the presence in V. fischeri of ompU, a gene encoding a 32.5-kDa protein homolog of two other OMPs, OmpU of V. cholerae (50.8% amino acid sequence identity) and OmpL of Photobacterium profundum (45.5% identity). A null mutation introduced into the V. fischeri ompU resulted in the loss of an OMP with an estimated molecular mass of about 34 kDa; genetic complementation of the mutant strain with a DNA fragment containing only the ompU gene restored the production of this protein. The expression of the V. fischeri OmpU was not significantly affected by either (i) iron or phosphate limitation or (ii) a mutation that renders V. fischeri defective in the synthesis of a homolog of the OMP-regulatory protein ToxR. The ompU mutant grew normally in complex nutrient media but was more susceptible to growth inhibition in the presence of either anionic detergents or the antimicrobial peptide protamine sulfate. Interestingly, colonization experiments showed that the ompU null mutant initiated a symbiotic association with

  7. AP4 method for two-tube nested PCR detection of AHPND isolates of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Sirintip Dangtip

    2015-11-01

    Full Text Available Our previous work on the mechanism of virulence for the unique isolates of Vibrio parahaemolyticus that cause acute hepatopancreatic necrosis disease (VPAHPND revealed that it was mediated by a binary Pir-like toxin pair ToxA and ToxB. These toxins are located on the pVA plasmid, a plasmid carried by AHPND-causing strain of V. parahaemolyticus with a size of approximately 69 kbp. Using the coding sequences of ToxA, a one-step PCR detection method for VPAHPND was introduced in June 2014 but had the limitation that attempts to adapt it into a nested PCR protocol were unsuccessful. As a result, low levels of VPAHPND in shrimp or other samples could not be detected without first preparing an enrichment broth culture to allow bacterial growth before extraction of template DNA. Here, we describe the AP4 (abbreviation of AHPND detection version 4 method, a two-tube nested PCR method that targets the tandem genes ToxA and ToxB, including the 12 bp spacer that separates them on pVA plasmid. Testing of the method revealed that it gave 100% positive and negative predictive values for VPAHPND using a panel of 104 bacterial isolates including 51 VPAHPND isolates and 53 non-AHPND isolates, the latter including 34 isolates of V. parahaemolyticus and 19 isolates of other bacteria found in shrimp ponds, including other Vibrio species. The AP4 nested PCR method was 100 times more sensitive (100 fg total DNA template than the one-step AP3 (10 pg total DNA template method, and it could detect VPAHPND in experimentally challenged shrimp by 6 h post immersion (n = 2/3, while AP3 could not detect is until 12 h post immersion (n = 1/3. Thus, the AP4 method may be useful in detecting VPAHPND isolates in samples where target material is limited (e.g., small tissue quantity or archived DNA and enrichment cannot be employed (i.e., frozen samples or samples preserved in alcohol.

  8. Lichtheimia species exhibit differences in virulence potential.

    Directory of Open Access Journals (Sweden)

    Volker U Schwartze

    Full Text Available Although the number of mucormycosis cases has increased during the last decades, little is known about the pathogenic potential of most mucoralean fungi. Lichtheimia species represent the second and third most common cause of mucormycosis in Europe and worldwide, respectively. To date only three of the five species of the genus have been found to be involved in mucormycosis, namely L. corymbifera, L. ramosa and L. ornata. However, it is not clear whether the clinical situation reflects differences in virulence between the species of Lichtheimia or whether other factors are responsible. In this study the virulence of 46 strains of all five species of Lichtheimia was investigated in chicken embryos. Additionally, strains of the closest-related genus Dichotomocladium were tested. Full virulence was restricted to the clinically relevant species while all strains of L. hyalospora, L. sphaerocystis and Dichotomocladium species were attenuated. Although virulence differences were present in the clinically relevant species, no connection between origin (environmental vs clinical or phylogenetic position within the species was observed. Physiological studies revealed no clear connection of stress resistance and carbon source utilization with the virulence of the strains. Slower growth at 37°C might explain low virulence of L. hyalospora, L. spaherocystis and Dichotomocladium; however, similarly slow growing strains of L. ornata were fully virulent. Thus, additional factors or a complex interplay of factors determines the virulence of strains. Our data suggest that the clinical situation in fact reflects different virulence potentials in the Lichtheimiaceae.

  9. Structural Genomics of Bacterial Virulence Factors

    National Research Council Canada - National Science Library

    Liddington, Robert

    2004-01-01

    We are applying a comprehensive yet focused structural genomics approach to determine the atomic resolution crystal structures of key bacterial virulence factors from high priority bacterial pathogens...

  10. Detection of viable and viable nonculturable Vibrio cholerae O1 through cultures and immunofluorescence in the Tucumán rivers, Argentina Detecção de Vibrio cholerae O1 viável e viável não cultivável, através de técnicas de cultivo e imunofluorescência nos rios de Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Olga Aulet

    2007-08-01

    Full Text Available Vibrio cholerae has been sporadically isolated from rivers in Tucumán, Argentina, since the outbreak in 1991. The aim of this study was to determine the environmental reservoir of the bacterium in these rivers, assessing the presence of Vibrio cholerae non-O1 and O1 (the latter both in its viable culturable and non culturable state and its relationship to environmental physicochemical variables. 18 water samplings were collected in the Salí River (in Canal Norte and Banda and the Lules River between 2003 and 2005. Physical-chemical measurements (pH, water temperature, electrical conductivity and dissolved oxygen were examined. Vibrio cholerae was investigated with conventional culture methods and with Direct Immunofluorescence (DFA-VNC in order to detect viable non culturable organisms. All isolated microorganisms corresponded to Vibrio cholerae non-O1 and non-O139 (Lules 26%, Canal Norte 33% and Banda 41%. The majority was found during spring and summer and correlated with temperature and pH. Non culturable Vibrio cholerae O1 was detected year round in 38 of the 54 water samples analyzed. Application of the Pearson correlation coefficient revealed that there was no relationship between positive immunofluorescence results and environmental physicochemical parameters. Genes coding for somatic antigen O1 were confirmed in all DFA-VNC-positive samples, whereas the virulence-associated ctxA and tcpA genes were confirmed in 24 samples.Vibrio cholerae tem sido isolado esporadicamente nos rios da Província de Tucumán, Argentina, desde outubro de 1991. O objetivo deste estudo foi localizar os reservatórios nestes rios, identificar a presença de Vibrio cholerae O1 (em estado cultivável e não cultivável e relacionar a presença desta bactéria com as variações físico-químicos da água. Foram coletadas dezoito amostras de água do rio Salí (nas localidades de Canal Norte e Banda e do rio Lules, entre 2003 e 2005. Estas foram submetidas a an

  11. Peruvian Vibrio cholerae O1 El Tor strains possess a distinct region in the Vibrio seventh pandemic island-II that differentiates them from the prototype seventh pandemic El Tor strains.

    Science.gov (United States)

    Nusrin, Suraia; Gil, Ana I; Bhuiyan, N A; Safa, Ashrafus; Asakura, Masahiro; Lanata, Claudio F; Hall, E; Miranda, H; Huapaya, B; Vargas G, Carmen; Luna, M A; Sack, D A; Yamasaki, Shinji; Nair, G Balakrish

    2009-03-01

    A collection of environmental and clinical strains of Vibrio cholerae O1 isolated from the beginning of the Latin American epidemic of cholera in 1991 to 2003 from multiple locations in Peru were characterized and compared with V. cholerae O1 El Tor strains of the seventh pandemic from the rest of the world (Asia, Africa, Australia and Europe) using a multilocus virulence gene profiling strategy and DNA sequencing. Peruvian strains differed from El Tor strains from the rest of the world by the failure of PCR to amplify genes VC0512, VC0513, VC0514 and VC0515 in the Vibrio seventh pandemic island-II (VSP-II) gene cluster. Sequencing of the VSP-II gene cluster and its flanking regions in one Peruvian strain (PERU-130) confirmed the PCR results, indicating that the Peruvian strain had low DNA homology (46.6 %) compared to the reference strain N16961 within the VSP-II region encompassing genes VC0511 to VC0515. Based on these differences in VSP-II, and based on the overall similarity between the pulsotypes of the Peruvian strains and the El Tor reference strain N16961, we concluded that the Peruvian, Eurasian and African strains belonged to the same clonal complex, and that the Peruvian strains represented variants that had independently evolved for a relatively short time. Since these ORFs in VSP-II of Peruvian strains are unique and conserved, they could form the basis for tracking the origin of the Peruvian strains and therefore of the Latin American pandemic.

  12. Structure of the Minor Pseudopilin EpsH From the Type 2 Secretion System of Vibrio Cholerae

    Energy Technology Data Exchange (ETDEWEB)

    Yanez, M.E.; Korotkov, K.V.; Abendroth, J.; Hol, W.G.J.

    2009-05-28

    Many Gram-negative bacteria use the multi-protein type II secretion system (T2SS) to selectively translocate virulence factors from the periplasmic space into the extracellular environment. In Vibrio cholerae the T2SS is called the extracellular protein secretion (Eps) system, which translocates cholera toxin and several enzymes in their folded state across the outer membrane. Five proteins of the T2SS, the pseudopilins, are thought to assemble into a pseudopilus, which may control the outer membrane pore EpsD, and participate in the active export of proteins in a 'piston-like' manner. We report here the 2.0 {angstrom} resolution crystal structure of an N-terminally truncated variant of EpsH, a minor pseudopilin from Vibrio cholerae. While EpsH maintains an N-terminal {alpha}-helix and C-terminal {beta}-sheet consistent with the type 4a pilin fold, structural comparisons reveal major differences between the minor pseudopilin EpsH and the major pseudopilin GspG from Klebsiella oxytoca: EpsH contains a large {beta}-sheet in the variable domain, where GspG contains an {alpha}-helix. Most importantly, EpsH contains at its surface a hydrophobic crevice between its variable and conserved {beta}-sheets, wherein a majority of the conserved residues within the EpsH family are clustered. In a tentative model of a T2SS pseudopilus with EpsH at its tip, the conserved crevice faces away from the helix axis. This conserved surface region may be critical for interacting with other proteins from the T2SS machinery.

  13. Evaluation of Cholera Toxin Expression in Different Populations of Vibrio cholera

    OpenAIRE

    Sedigheh Ebrahimi Kasgari; Mahnaz Nourani; Yousef Yahyapour; Seyed Ehsanollah Mousavi; Enayatollah Kalantar; Hami Kaboosi; Seyed Mahmoud Amin Marashi

    2015-01-01

    Background: Cholera is one of the most diseases of human. Cholera toxin is the most important pathogenic factor in humans that causes diarrhea. The cholera toxin is produced by V. cholerae and CTXфPhage. Objectives: In this study, we have investigated the production cholera toxin with different density of Vibrio cholerae. Materials and Methods: With this propose we inoculated classical strain O1 of Vibrio cholerae ATCC 14035 and Vibrio cholerae O1biovar El Tor N16961 into th...

  14. Antimicrobial effect of dietary oregano essential oil against Vibrio bacteria in shrimps

    OpenAIRE

    Gracia-Valenzuela M.H.; Vergara-Jiménez M.J.; Baez-Flores M.E.; Cabrera-Chavez F.

    2014-01-01

    The effect of dietary oregano essential oils on the growth of Vibrio bacteria in shrimps was evaluated. Shrimps were fed: (i) food with oregano oil with a high level of thymol; (ii) food with oregano oil with a high level of carvacrol, and (iii) food without oregano oil (the control). The animals were infected by three species of Vibrio (vulnificus, parahaemolyticus and cholerae). The microbial counts of Vibrio species were significantly lower (p

  15. Evolution of viral virulence: empirical studies

    Science.gov (United States)

    Kurath, Gael; Wargo, Andrew R.

    2016-01-01

    The concept of virulence as a pathogen trait that can evolve in response to selection has led to a large body of virulence evolution theory developed in the 1980-1990s. Various aspects of this theory predict increased or decreased virulence in response to a complex array of selection pressures including mode of transmission, changes in host, mixed infection, vector-borne transmission, environmental changes, host vaccination, host resistance, and co-evolution of virus and host. A fundamental concept is prediction of trade-offs between the costs and benefits associated with higher virulence, leading to selection of optimal virulence levels. Through a combination of observational and experimental studies, including experimental evolution of viruses during serial passage, many of these predictions have now been explored in systems ranging from bacteriophage to viruses of plants, invertebrates, and vertebrate hosts. This chapter summarizes empirical studies of viral virulence evolution in numerous diverse systems, including the classic models myxomavirus in rabbits, Marek's disease virus in chickens, and HIV in humans. Collectively these studies support some aspects of virulence evolution theory, suggest modifications for other aspects, and show that predictions may apply in some virus:host interactions but not in others. Finally, we consider how virulence evolution theory applies to disease management in the field.

  16. Anaerobiosis induced virulence of Salmonella typhi

    DEFF Research Database (Denmark)

    Kapoor, Sarika; Singh, R D; Sharma, P C

    2002-01-01

    BACKGROUND & OBJECTIVES: Anaerobic conditions are frequently encountered by pathogens invading the gastrointestinal tract due to low/limiting oxygen conditions prevalent in the small intestine. This anaerobic stress has been suggested to enhance the virulence of gut pathogens. In the present stud...... dismutase (SOD) and catalase. INTERPRETATION & CONCLUSION: Our results suggest that exposure of S. Typhi to anaerobic conditions enhances its virulence....

  17. VibrioBase: A Model for Next-Generation Genome and Annotation Database Development

    Directory of Open Access Journals (Sweden)

    Siew Woh Choo

    2014-01-01

    Full Text Available To facilitate the ongoing research of Vibrio spp., a dedicated platform for the Vibrio research community is needed to host the fast-growing amount of genomic data and facilitate the analysis of these data. We present VibrioBase, a useful resource platform, providing all basic features of a sequence database with the addition of unique analysis tools which could be valuable for the Vibrio research community. VibrioBase currently houses a total of 252 Vibrio genomes developed in a user-friendly manner and useful to enable the analysis of these genomic data, particularly in the field of comparative genomics. Besides general data browsing features, VibrioBase offers analysis tools such as BLAST interfaces and JBrowse genome browser. Other important features of this platform include our newly developed in-house tools, the pairwise genome comparison (PGC tool, and pathogenomics profiling tool (PathoProT. The PGC tool is useful in the identification and comparative analysis of two genomes, whereas PathoProT is designed for comparative pathogenomics analysis of Vibrio strains. Both of these tools will enable researchers with little experience in bioinformatics to get meaningful information from Vibrio genomes with ease. We have tested the validity and suitability of these tools and features for use in the next-generation database development.

  18. Virulence of Fusarium species to alfalfa seedlings

    Directory of Open Access Journals (Sweden)

    Krnjaja Vesna

    2005-01-01

    Full Text Available In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. prolifera- tum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected at four locations in Serbia based on symptoms of wilting caused by Fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivar K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.

  19. Virulence of Fusarium species to alfalfa seedlings

    Directory of Open Access Journals (Sweden)

    Krnjaja Vesna

    2005-01-01

    Full Text Available In in vitro conditions, virulence of 91 isolates of species Fusarium genus (F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. arthrosporioides, F. proliferatum, F. avenaceum, F. semitectum, F. tricinctum, F. sporotrichioides and F. graminearum towards alfalfa seedlings was investigated. Isolates of investigated species originated from diseased alfalfa plants collected on four locations in Serbia based on symptoms of wilting caused by fusarium and root rotting. Pathogenicity and virulence of investigated isolates of Fusarium spp. were determined by visual evaluation of inoculated seedlings of cultivars K28 in laboratory conditions. All isolated of investigated species had pathogenic effect on alfalfa seedlings, which expressed symptoms such as necrosis of root, moist rotting and "melting of seedlings". Colour of necrotic root tissue varied from light brown, brown, lipstick red to explicit black, depending on the Fusarium species. Strong virulence was established in 48 isolates, medium virulence in 31 and weak virulence in 12 isolates.

  20. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010.

    Directory of Open Access Journals (Sweden)

    Rolf S Kaas

    Full Text Available The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE elements were identified and annotated. A global phylogeny (378 genomes was inferred using a single nucleotide polymorphism (SNP analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

  1. Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

    2016-01-01

    BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...... methods. Isolates were confirmed as V. cholerae by detection of the outer membrane protein gene (ompW) using polymerase chain reaction (PCR). Isolates were further tested for antibiotic susceptibility and presence of virulence genes including, cholera enterotoxin gene (ctx), the toxin co-regulated pilus...

  2. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer; Ngandjio, Antoinette; Nzouankeu, Ariane

    2016-01-01

    a single nucleotide polymorphism (SNP) analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae......The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic...... make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE) elements were identified and annotated. A global phylogeny (378 genomes) was inferred using...

  3. Proteomic Characterization of Yersinia pestis Virulence

    Energy Technology Data Exchange (ETDEWEB)

    Chromy, B; Murphy, G; Gonzales, A; Fitch, J P; McCutchen-Maloney, S L

    2005-01-05

    Yersinia pestis, the etiological agent of plague, functions via the Type III secretion mechanism whereby virulence factors are induced upon interactions with a mammalian host. Here, the Y. pestis proteome was studied by two-dimensional differential gel electrophoresis (2-D DIGE) under physiologically relevant growth conditions mimicking the calcium concentrations and temperatures that the pathogen would encounter in the flea vector and upon interaction with the mammalian host. Over 4100 individual protein spots were detected of which hundreds were differentially expressed in the entire comparative experiment. A total of 43 proteins that were differentially expressed between the vector and host growth conditions were identified by mass spectrometry. Expected differences in expression were observed for several known virulence factors including catalase-peroxidase (KatY), murine toxin (Ymt), plasminogen activator (Pla), and F1 capsule antigen (Caf1), as well as putative virulence factors. Chaperone proteins and signaling molecules hypothesized to be involved in virulence due to their role in Type III secretion were also identified. Other differentially expressed proteins not previously reported to contribute to virulence are candidates for more detailed mechanistic studies, representing potential new virulence determinants. For example, several sugar metabolism proteins were differentially regulated in response to lower calcium and higher temperature, suggesting these proteins, while not directly connected to virulence, either represent a metabolic switch for survival in the host environment or may facilitate production of virulence factors. Results presented here contribute to a more thorough understanding of the virulence mechanism of Y. pestis through proteomic characterization of the pathogen under induced virulence.

  4. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

    Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  5. Mutation of Bacterium Vibrio gazogenes for Selective Preparation of Colorants

    OpenAIRE

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D.; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples show...

  6. Wind direction and its linkage with Vibrio cholerae dissemination.

    Science.gov (United States)

    Paz, Shlomit; Broza, Meir

    2007-02-01

    The relevance of climatic events as causative factors for cholera epidemics is well known. However, examinations of the involvement of climatic factors in intracontinental disease distribution are still absent. The spreading of cholera epidemics may be related to the dominant wind direction over land. We examined the geographic diffusion of three cholera outbreaks through their linkage with the wind direction: a) the progress of Vibrio cholerae O1 biotype El Tor in Africa during 1970-1971 and b) again in 2005-2006; and c) the rapid spread of Vibrio cholerae O139 over India during 1992-1993. We also discuss the possible influence of the wind direction on windborn dissemination by flying insects, which may serve as vectors. Analysis of air pressure data at sea level and at several altitudes over Africa, India, and Bangladesh show a correspondence between the dominant wind direction and the intracontinental spread of cholera. We explored the hypothesis that winds have assisted the progress of cholera Vibrios throughout continents. The current analysis supports the hypothesis that aeroplankton (the tiny life forms that float in the air and that may be caught and carried upward by the wind, landing far from their origin) carry the cholera bacteria from one body of water to an adjacent one. This finding may improve our understanding of how climatic factors are involved in the rapid distribution of new strains throughout a vast continental area. Awareness of the aerial transfer of Vibrio cholerae may assist health authorities by improving the prediction of the disease's geographic dissemination.

  7. Adsorption kinetics of laterally and polarly flagellated Vibrio.

    OpenAIRE

    Belas, M R; Colwell, R R

    1982-01-01

    The adsorption of laterally and polarly flagellated bacteria to chitin was measured, and from the data obtained, a modified Langmuir adsorption isotherm was derived. Results indicated that the adsorption of laterally flagellated Vibrio parahaemolyticus follows the Langmuir adsorption isotherm, a type of adsorption referred to as surface saturation kinetics, when conditions are favorable for the production of lateral flagella. When conditions were not favorable for the production of lateral fl...

  8. 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.

    Science.gov (United States)

    Starks, Angela M; Bourdage, Keri L; Thiaville, Patrick C; Gulig, Paul A

    2006-07-01

    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

  9. Identification of Vibrio spp. with a set of dichotomous keys.

    Science.gov (United States)

    Noguerola, I; Blanch, A R

    2008-07-01

    To define a binary biochemical key for the identification of all recognized Vibrio spp. A matrix of phenotypical results was developed based on the previous taxonomical studies and the first description manuscripts. A unification of results from various sources was also performed to integrate different taxonomical studies within the same data matrix. Established criteria for selecting the optimal set of tests yielded the highest discrimination, as well as the lowest number of tests. An initial identification key was defined using arginine dihydrolase, lysine decarboxylase and ornithine decarboxylase tests, as well as defining eight different clusters. This key leads each cluster to a secondary key for species identification. Most of Vibrio spp. presented an identification threshold of 100%. A new set of biochemical keys has been determined provides a scheme for the rapid identification of clinical and environmental species of Vibrio. No more than 14 are needed for even the most complicated identifications. This newly defined set of keys updates and improves similar findings published in previous studies. These biochemical keys are designed for use in routine applications, particularly in environmental and clinical studies involving a high number of isolates.

  10. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    Science.gov (United States)

    Sharma, Anshu; Baral, Dinesh; Rawat, Kamla; Solanki, Pratima R.; Bohidar, H. B.

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3O4)) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe3O4 and CA-Fe3O4/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, CA-Fe3O4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe3O4) and 189.51 nm (CA-Fe3O4) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2O3/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL-1 with a low detection limit of 0.32 ng mL-1, sensitivity 0.03 Ω/ng ml-1 cm-2, and reproducibility more than 11 times.

  11. Insight into the evolution of Vibrio vulnificus biotype 3's genome.

    Science.gov (United States)

    Efimov, Vera; Danin-Poleg, Yael; Raz, Nili; Elgavish, Sharona; Linetsky, Alex; Kashi, Yechezkel

    2013-01-01

    Vibrio vulnificus is an aquatic bacterium and an important human pathogen. Strains of V. vulnificus are biochemically classified into three biotypes. The newly emerged biotype 3 appears to be rather clonal and geographically restricted to Israel, where it caused an outbreak of wound infections and bacteremia. To understand the evolution of the bacterium's genome, we sequenced and analyzed the genome of biotype 3 strain VVyb1(BT3), and then conducted a microbial environmental survey of the hypothesized niche from which it probably evolved. The genome of this environmental isolate revealed higher similarity to the published biotype 1 genomes of clinical strains (90%) than to the environmental strains (87%), supporting the virulence of the biotype 3 group. Moreover, 214 of the total 5361 genes were found to be unique to strain VVyb1(BT3), having no sequence similarity to any of the known genomes of V. vulnificus; 35 of them function in DNA mobility and rearrangement, supporting the role of horizontal gene transfer in genome evolution. Interestingly, 29 of the "unique" genes had homologies among Shewanella species. In a survey conducted in aquaculture ponds in Israel, we successfully co-isolated Shewanella and V. vulnificus from the same niche, further supporting the probable contribution of Shewanella to the genome evolution of biotype 3. Indeed, one gene was found in a S. algae isolate. Surprisingly, molecular analysis revealed that some of the considered unique genes are harbored by non-sequenced biotype 1 strains isolated from the same environment. Finally, analyses of the biotype 3 genome together with the environmental survey suggested that its genome originated from a biotype 1 Israeli strain that acquired a rather small number of genes from other bacterial species in the niche, such as Shewanella. Therefore, aquaculture is likely to play a major role as a man-made ecological niche in bacterial evolution, leading the emergence of new pathogenic groups in V

  12. MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice

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    Celia Murciano

    2017-07-01

    Full Text Available Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13, which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apoptosis, respectively. Finally, we tested the hypothesis that RtxA13 contributes to human death caused by this zoonotic serovar by triggering an early cytokine storm in blood. To this end, we used a Bt2-SerE strain (R99 together with its rtxA13 deficient mutant, and a Bt1 strain (YJ016 producing RtxA11 (the most studied MARTXVv together with its rtxA11 deficient mutant, as controls. Our results showed that RtxA13 was essential for virulence, as R99ΔΔrtxA13 was completely avirulent in our murine model of infection, and that R99, but not strain YJ016, induced an early, strong and dysregulated immune response involving the up-regulation of a high number of genes. This dysregulated immune response was directly linked to RtxA13. Based on these results and those obtained ex vivo (human blood, we propose a model of infection for the zoonotic serovar of V. vulnificus, in which RtxA13 would act as a sepsis-inducing toxin.

  13. Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam.

    Science.gov (United States)

    Takemura, Taichiro; Murase, Kazunori; Maruyama, Fumito; Tran, Thi Luong; Ota, Atsushi; Nakagawa, Ichiro; Nguyen, Dong Tu; Ngo, Tu Cuong; Nguyen, Thi Hang; Tokizawa, Asako; Morita, Masatomo; Ohnishi, Makoto; Nguyen, Binh Minh; Yamashiro, Tetsu

    2017-10-01

    Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters for Vibrio cholerae presence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization of V. cholerae strains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, four V. cholerae O1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene, ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carried tcpA gene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergent V. cholera strains and serve as a reservoir for multiple V. cholerae virulence-associated genes which may be exchanged via mobile genetic elements. Therefore, continuous monitoring and genetic characterization of V. cholerae strains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution of V. cholerae. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Vibrio cholerae infection of Drosophila melanogaster mimics the human disease cholera.

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    Nathan S Blow

    2005-09-01

    Full Text Available Cholera, the pandemic diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, continues to be a major public health challenge in the developing world. Cholera toxin, which is responsible for the voluminous stools of cholera, causes constitutive activation of adenylyl cyclase, resulting in the export of ions into the intestinal lumen. Environmental studies have demonstrated a close association between V. cholerae and many species of arthropods including insects. Here we report the susceptibility of the fruit fly, Drosophila melanogaster, to oral V. cholerae infection through a process that exhibits many of the hallmarks of human disease: (i death of the fly is dependent on the presence of cholera toxin and is preceded by rapid weight loss; (ii flies harboring mutant alleles of either adenylyl cyclase, Gsalpha, or the Gardos K channel homolog SK are resistant to V. cholerae infection; and (iii ingestion of a K channel blocker along with V. cholerae protects wild-type flies against death. In mammals, ingestion of as little as 25 mug of cholera toxin results in massive diarrhea. In contrast, we found that ingestion of cholera toxin was not lethal to the fly. However, when cholera toxin was co-administered with a pathogenic strain of V. cholerae carrying a chromosomal deletion of the genes encoding cholera toxin, death of the fly ensued. These findings suggest that additional virulence factors are required for intoxication of the fly that may not be essential for intoxication of mammals. Furthermore, we demonstrate for the first time the mechanism of action of cholera toxin in a whole organism and the utility of D. melanogaster as an accurate, inexpensive model for elucidation of host susceptibility to cholera.

  15. ToxR of Vibrio cholerae affects biofilm, rugosity and survival with Acanthamoeba castellanii

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    Valeru Soni P

    2012-01-01

    Full Text Available Abstract Background Vibrio cholerae causes the diarrheal disease cholera and utilizes different survival strategies in aquatic environments. V. cholerae can survive as free-living or in association with zooplankton and can build biofilm and rugose colonies. The bacterium expresses cholera toxin (CT and toxin-coregulated pilus (TCP as the main virulence factors. These factors are co-regulated by a transcriptional regulator ToxR, which modulates expression of outer membrane proteins (OmpU and (OmpT. The aims of this study were to disclose the role of ToxR in expression of OmpU and OmpT, biofilm and rugose colony formation as well as in association with the free-living amoeba Acanthamoeba castellanii at different temperatures. Results The toxR mutant V. cholerae produced OmpT, significant biofilm and rugose colonies compared to the wild type that produced OmpU, decreased biofilm and did not form rugoes colonies at 30°C. Interestingly, neither the wild type nor toxR mutant strain could form rugose colonies in association with the amoebae. However, during the association with the amoebae it was observed that A. castellanii enhanced survival of V. cholerae wild type compared to toxR mutant strain at 37°C. Conclusions ToxR does seem to play some regulatory role in the OmpT/OmpU expression shift, the changes in biofilm, rugosity and survival with A. castellanii, suggesting a new role for this regulatory protein in the environments.

  16. Virulence Factors of A Review

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    Bruna M. Roesler

    2014-07-01

    Full Text Available Helicobacter pylori is a spiral-shaped Gram-negative bacterium that colonizes the human stomach and can establish a long-term infection of the gastric mucosa, a condition that affects the relative risk of developing various clinical disorders of the upper gastrointestinal tract, such as chronic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT lymphoma, and gastric adenocarcinoma. H. pylori presents a high-level of genetic diversity, which can be an important factor in its adaptation to the host stomach and also for the clinical outcome of infection. There are important H. pylori virulence factors that, along with host characteristics and the external environment, have been associated with the different occurrences of diseases. This review is aimed to analyzing and summarizing the main of them and possible associations with the clinical outcome.

  17. Genome-Wide Biases in the Rate and Molecular Spectrum of Spontaneous Mutations in Vibrio cholerae and Vibrio fischeri.

    Science.gov (United States)

    Dillon, Marcus M; Sung, Way; Sebra, Robert; Lynch, Michael; Cooper, Vaughn S

    2017-01-01

    The vast diversity in nucleotide composition and architecture among bacterial genomes may be partly explained by inherent biases in the rates and spectra of spontaneous mutations. Bacterial genomes with multiple chromosomes are relatively unusual but some are relevant to human health, none more so than the causative agent of cholera, Vibrio cholerae Here, we present the genome-wide mutation spectra in wild-type and mismatch repair (MMR) defective backgrounds of two Vibrio species, the low-%GC squid symbiont V. fischeri and the pathogen V. cholerae, collected under conditions that greatly minimize the efficiency of natural selection. In apparent contrast to their high diversity in nature, both wild-type V. fischeri and V. cholerae have among the lowest rates for base-substitution mutations (bpsms) and insertion-deletion mutations (indels) that have been measured, below 10(-)(3)/genome/generation. Vibrio fischeri and V. cholerae have distinct mutation spectra, but both are AT-biased and produce a surprising number of multi-nucleotide indels. Furthermore, the loss of a functional MMR system caused the mutation spectra of these species to converge, implying that the MMR system itself contributes to species-specific mutation patterns. Bpsm and indel rates varied among genome regions, but do not explain the more rapid evolutionary rates of genes on chromosome 2, which likely result from weaker purifying selection. More generally, the very low mutation rates of Vibrio species correlate inversely with their immense population sizes and suggest that selection may not only have maximized replication fidelity but also optimized other polygenic traits relative to the constraints of genetic drift. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Distribution of virulence plasmids within Salmonellae.

    Science.gov (United States)

    Woodward, M J; McLaren, I; Wray, C

    1989-03-01

    The virulence region of the Salmonella dublin 50 MDa plasmid shared homology with 678 of 1021 salmonellae tested in colony hybridization experiments. The majority of S. dublin, S. typhimurium and S. enteritidis isolates tested hybridized with the region whereas, with the exception of S. hessarek, S. pullorum and S. gallinarum, other serotypes did not. Homologous virulence regions were plasmid encoded. In S. typhimurium a common 60 MDa plasmid was present in all phage types tested but not in DT4, DT37 and DT170. Smaller plasmids showing partial homology were found in DT12, DT18, DT193 and DT204C. In S. enteritidis a distinct plasmid profile for each of eight phage types was observed. Hybridizing plasmids were found in DT3, DT4, DT8, DT9 and DT11 whereas DT7, which was plasmid free, and DT10 and DT14, which harboured plasmids, did not hybridize. The extent of homology shared between S. dublin, S. typhimurium and S. enteritidis virulence plasmids was about 10 MDa and appeared conserved. Virulence plasmids from S. typhimurium and S. enteritidis did not show homology with a region of the S. dublin 50 MDa plasmid which was not associated with virulence functions whereas plasmids of about 24 MDa and 38 MDa in some S. typhimurium phage types did. The association of conserved virulence regions upon differing plasmids within salmonellae is discussed with reference to possible mechanisms of distribution and evolution of virulence genes.

  19. The Vibrio cholerae VprA-VprB Two-Component System Controls Virulence Through Endotoxin Modification

    Science.gov (United States)

    2014-12-23

    Aldrich. Restriction endonucleases and T4 DNA ligase were obtained from New England Biolabs Inc. (NEB). The QuikChange site-directed mutagenesis system...NdeI and HindIII restriction endonucleases and cloned into the expression plasmid pET21a (see Table S3). The generated plasmid pET-1320 results in...the PalmE region, restricting the radial complex dispersion of the 32P-labeled promoter region of almE (32P-PalmE). Total mobility of the double

  20. The extinction differential induced virulence macroevolution

    Science.gov (United States)

    Zhang, Feng; Xu, Liufang; Wang, Jin

    2014-04-01

    We apply the potential-flux landscape theory to deal with the large fluctuation induced extinction phenomena. We quantify the most probable extinction pathway on the landscape and measure the extinction risk by the landscape topography. In this Letter, we investigate the disease extinction through an epidemic model described by a set of chemical reaction. We found the virulence-differential-dependent symbioses between mother and daughter pathogen species: mutualism and parasitism. The symbioses, whether mutualism or parasitism, benefit the higher virulence species. This implies that speciation towards lower virulence is an effective strategy for a pathogen species to reduce its extinction risk.

  1. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa.

    Science.gov (United States)

    Osunla, Charles A; Okoh, Anthony I

    2017-10-07

    Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens.

  2. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Charles A. Osunla

    2017-10-01

    Full Text Available Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens.

  3. The Occurrence of Vibrio species in the Gut of Sardinella madrensis ...

    African Journals Online (AJOL)

    The occurrence of vibrio bacteria in the gut of “Songu”: Sardinella madrensis was investigated using enrichment procedures. Seventy percent (70%) of the total fish samples examined were positive for vibrios. The mean bacterial counts ranged between 2.68 x 102 to 1.30 x 104 cfu/g in all the fish samples. The weight of fish ...

  4. Onderzoek pathogene vibrio soorten in Nederlandse mosselen en oesters in augustus en september 2003

    NARCIS (Netherlands)

    Aalberts, C.H.J.

    2003-01-01

    Naar aanleiding van de hoge weerstemperatuur in augustus 2003 zijn in de kweek- en verwatergebieden van mosselen en oesters in Nederland enkele monsters onderzocht op de aanwezigheid van voor de mens pathogene vibrio soorten. In geen van de 18 monsters is Vibrio parahaemolyticus, vulnificus of

  5. Complete genome sequence for the shellfish pathogen Vibrio coralliilyticus RE98 isolated from a shellfish hatchery

    Science.gov (United States)

    Vibrio coralliilyticus is a pathogen of corals and larval shellfish. Publications on strain RE98 list it as a Vibrio tubiashii; however, whole genome sequencing confirms RE98 as V. coralliilyticus containing a total of 6,037,824 bp consisting of two chromosomes (3,420,228 and 1,917,482 bp), and two...

  6. Bactericidal effect of lactoferrin and lactoferrin chimera against halophilic Vibrio parahaemolyticus

    NARCIS (Netherlands)

    Leon-Sicairos, N.; Canizalez-Roman, A.; de la Garza, M.; Reyes-Lopez, M.; Zazueta-Beltran, J.; Nazmi, K.; Gomez-Gil, B.; Bolscher, J.G.

    2009-01-01

    Infections caused by Vibrio parahaemolyticus, an halophilic member of the genus Vibrio, have increased globally in the last 5 years. Diarrhea caused by V. parahaemolyticus results from eating raw or undercooked seafood. The aim of this work was to investigate whether lactoferrin and some

  7. Vibrio ecology in PNW - The Ecology of Vibrio parahaemolyticus in the Pacific Northwest: Implications for risk assessment and early warning systems

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the past decade, there has been a significant increase in Vibrio parahaemolyticus-related gastroenteritis from the consumption of raw oysters harvested in...

  8. Biochemical Basis of Virulence in Epidemic Typhus.

    Science.gov (United States)

    1983-01-01

    properties include antibiotic resistance, toxin production , fertility, bacteriocin production , and production of virulence factors. (4). Numerous...sample. The rickettsial leukotoxin was probably not a soluble product , was active in the absence of phagocytosis, and was inhibited by inactivation of

  9. Virulence Factors IN Fungi OF Systemic Mycoses

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    KUROKAWA Cilmery Suemi

    1998-01-01

    Full Text Available Pathogenic fungi that cause systemic mycoses retain several factors which allow their growth in adverse conditions provided by the host, leading to the establishment of the parasitic relationship and contributing to disease development. These factors are known as virulence factors which favor the infection process and the pathogenesis of the mycoses. The present study evaluates the virulence factors of pathogenic fungi such as Blastomyces dermatitidis, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum and Paracoccidioides brasiliensis in terms of thermotolerance, dimorphism, capsule or cell wall components as well as enzyme production. Virulence factors favor fungal adhesion, colonization, dissemination and the ability to survive in hostile environments and elude the immune response mechanisms of the host. Both the virulence factors presented by different fungi and the defense mechanisms provided by the host require action and interaction of complex processes whose knowledge allows a better understanding of the pathogenesis of systemic mycoses.

  10. Application of a paper based device containing a new culture medium to detect Vibrio cholerae in water samples collected in Haiti.

    Science.gov (United States)

    Briquaire, Romain; Colwell, Rita R; Boncy, Jacques; Rossignol, Emmanuel; Dardy, Aline; Pandini, Isabelle; Villeval, François; Machuron, Jean-Louis; Huq, Anwar; Rashed, Shah; Vandevelde, Thierry; Rozand, Christine

    2017-02-01

    Cholera is now considered to be endemic in Haiti, often with increased incidence during rainy seasons. The challenge of cholera surveillance is exacerbated by the cost of sample collection and laboratory analysis. A diagnostic tool is needed that is low cost, easy-to-use, and able to detect and quantify Vibrio cholerae accurately in water samples within 18-24h, and perform reliably in remote settings lacking laboratory infrastructure and skilled staff. The two main objectives of this study were to develop and evaluate a new culture medium embedded in a new diagnostic tool (PAD for paper based analytical device) for detecting Vibrio cholerae from water samples collected in Haiti. The intent is to provide guidance for corrective action, such as chlorination, for water positive for V. cholerae epidemic strains. For detecting Vibrio cholerae, a new chromogenic medium was designed and evaluated as an alternative to thiosulfate citrate bile salts sucrose (TCBS) agar for testing raw water samples. Sensitivity and specificity of the medium were assessed using both raw and spiked water samples. The Vibrio cholerae chromogenic medium was proved to be highly selective against most of the cultivable bacteria in the water samples, without loss of sensitivity in detection of V. cholerae. Thus, reliability of this new culture medium for detection of V. cholerae in the presence of other Vibrio species in water samples offers a significant advantage. A new paper based device containing the new chromogenic medium previously evaluated was compared with reference methods for detecting V. cholerae from spiked water sample. The microbiological PAD specifications were evaluated in Haiti. More precisely, a total of 185 water samples were collected at five sites in Haiti, June 2014 and again in June 2015. With this new tool, three V. cholerae O1 and 17 V. cholerae non-O1/O139 strains were isolated. The presence of virulence-associated and regulatory genes, including ctxA, zot, ace, and tox

  11. Structural Genomics of Bacterial Virulence Factors

    Science.gov (United States)

    2006-05-01

    plant proteins. Its presence in the virulence-related pXO1 plasmid of Bacillus anthracis (pX01-01) as well as in several other pathogens makes it a...from several other bacilli; Enterococcus, Listeria , Lactococcus, Lactobacillus, or other Bacillus species. Function of proteins from this family is...virulence plasmids. Infect Immun 71: 2736-2743. Braun, L. and P. Cossart. 2000. Interactions between Listeria monocytogenes and host mammalian cells

  12. A Vibrio parahaemolyticus T3SS Effector Mediates Pathogenesis by Independently Enabling Intestinal Colonization and Inhibiting TAK1 Activation

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    Xiaohui Zhou

    2013-05-01

    Full Text Available Vibrio parahaemolyticus type III secretion system 2 (T3SS2 is essential for the organism’s virulence, but the effectors required for intestinal colonization and induction of diarrhea by this pathogen have not been identified. Here, we identify a type III secretion system (T3SS2-secreted effector, VopZ, that is essential for V. parahaemolyticus pathogenicity. VopZ plays distinct, genetically separable roles in enabling intestinal colonization and diarrheagenesis. Truncation of VopZ prevents V. parahaemolyticus colonization, whereas deletion of VopZ amino acids 38–62 abrogates V. parahaemolyticus-induced diarrhea and intestinal pathology but does not impair colonization. VopZ inhibits activation of the kinase TAK1 and thereby prevents the activation of MAPK and NF-κB signaling pathways, which lie downstream. In contrast, the VopZ internal deletion mutant cannot counter the activation of pathways regulated by TAK1. Collectively, our findings suggest that VopZ’s inhibition of TAK1 is critical for V. parahaemolyticus to induce diarrhea and intestinal pathology.

  13. Isolation and characterization of a N4-like lytic bacteriophage infecting Vibrio splendidus, a pathogen of fish and bivalves.

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    Pantelis Katharios

    Full Text Available A novel virulent bacteriophage, vB_VspP_pVa5, infecting a strain of Vibrio splendidus was isolated from a sea-cage aquaculture farm in Greece, and characterized using microbiological methods and genomic analysis. Bacteriophage vB_VspP_pVa5 is a N4-like podovirus with an icosahedral head measuring 85 nm in length and a short non-contractile tail. The phage had a narrow host range infecting only the bacterial host, a latent period of 30 min and a burst size of 24 virions per infected bacterium. Its genome size was 78,145 bp and genomic analysis identified 107 densely-packed genes, 40 of which could be annotated. In addition to the very large virion encapsulated DNA-dependent RNA polymerase which is the signature of the N4-like genus, an interesting feature of the novel phage is the presence of a self-splicing group I intron in the thymidylate synthase gene. A tRNAStop interrupted by a ~2.5kb open reading frame-containing area was also identified. The absence of genes related to lysogeny along with the high efficacy observed during in vitro cell lysis trials, indicate that the vB_VspP_pVa5 is a potential candidate component in a bacteriophage cocktail suitable for the biological control of V. splendidus in aquaculture.

  14. Expression and Quorum Sensing Regulation of Type III Secretion System Genes of Vibrio harveyi during Infection of Gnotobiotic Brine Shrimp

    Science.gov (United States)

    Ruwandeepika, H. A. Darshanee; Karunasagar, Indrani; Bossier, Peter; Defoirdt, Tom

    2015-01-01

    Type III secretion systems enable pathogens to inject their virulence factors directly into the cytoplasm of the host cells. The type III secretion system of Vibrio harveyi, a major pathogen of aquatic organisms and a model species in quorum sensing studies, is repressed by the quorum sensing master regulator LuxR. In this study, we found that during infection of gnotobiotic brine shrimp larvae, the expression levels of three type III secretion operons in V. harveyi increased within the first 12h after challenge and decreased again thereafter. The in vivo expression levels were highest in a mutant with a quorum sensing system that is locked in low cell density configuration (minimal LuxR levels) and lowest in a mutant with a quorum sensing system that is locked in the high cell density configuration (maximal LuxR levels), which is consistent with repression of type III secretion by LuxR. Remarkably, in vivo expression levels of the type III secretion system genes were much (> 1000 fold) higher than the in vitro expression levels, indicating that (currently unknown) host factors significantly induce the type III secretion system. Given the fact that type III secretion is energy-consuming, repression by the quorum sensing master regulators might be a mechanism to save energy under conditions where it does not provide an advantage to the cells. PMID:26636765

  15. In Vitro Inhibition of Cholera Toxin Production in Vibrio cholerae by Methanol Extract of Sweet Fennel Seeds and Its Components.

    Science.gov (United States)

    Chatterjee, Shruti; Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Chowdhury, Nityananda; Asakura, Masahiro; Hinenoya, Atsushi; Ramamurthy, T; Iwaoka, Emiko; Aoki, Shunji; Yamasaki, Shinji

    2016-09-21

    A newly emerged Vibrio cholerae O1 El Tor variant strain with multidrug resistance is considered a threat to public health. Recent strategies to suppress virulence factors production instead of bacterial growth may lead to less selective pressure for the emergence of resistant strains. The use of spices and their active constituents as the inhibitory agents against cholera toxin (CT) production in V. cholerae may be an alternative approach to treat cholera. In this study, we examined the potential of sweet fennel seed (Foeniculum vulgare Miller var. dulce) methanol extract to inhibit CT production in V. cholerae without affecting viability. The methanol extract of sweet fennel seeds significantly inhibited CT production in various V. cholerae strains, regardless of serogroup or biotype. Interestingly, trans-anethole and 4-allylanisole, essential oil components of sweet fennel seeds, also demonstrated similar effects. Here, we report that sub-bactericidal concentrations of sweet fennel seed methanol extract and its major components can drastically inhibit CT production in various V. cholerae strains.

  16. The Vibrio cholerae quorum-sensing autoinducer CAI-1: analysis of the biosynthetic enzyme CqsA

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, R.; Bolitho, M; Higgins, D; Lu, W; Ng, W; Jeffrey, P; Rabinowitz, J; Semmelhack, M; Hughson, F; Bassler, B

    2009-01-01

    Vibrio cholerae, the bacterium that causes the disease cholera, controls virulence factor production and biofilm development in response to two extracellular quorum-sensing molecules, called autoinducers. The strongest autoinducer, called CAI-1 (for cholera autoinducer-1), was previously identified as (S)-3-hydroxytridecan-4-one. Biosynthesis of CAI-1 requires the enzyme CqsA. Here, we determine the CqsA reaction mechanism, identify the CqsA substrates as (S)-2-aminobutyrate and decanoyl coenzyme A, and demonstrate that the product of the reaction is 3-aminotridecan-4-one, dubbed amino-CAI-1. CqsA produces amino-CAI-1 by a pyridoxal phosphate-dependent acyl-CoA transferase reaction. Amino-CAI-1 is converted to CAI-1 in a subsequent step via a CqsA-independent mechanism. Consistent with this, we find cells release {ge}100 times more CAI-1 than amino-CAI-1. Nonetheless, V. cholerae responds to amino-CAI-1 as well as CAI-1, whereas other CAI-1 variants do not elicit a quorum-sensing response. Thus, both CAI-1 and amino-CAI-1 have potential as lead molecules in the development of an anticholera treatment.

  17. Isolation and characterization of a N4-like lytic bacteriophage infecting Vibrio splendidus, a pathogen of fish and bivalves.

    Science.gov (United States)

    Katharios, Pantelis; Kalatzis, Panos G; Kokkari, Constantina; Sarropoulou, Elena; Middelboe, Mathias

    2017-01-01

    A novel virulent bacteriophage, vB_VspP_pVa5, infecting a strain of Vibrio splendidus was isolated from a sea-cage aquaculture farm in Greece, and characterized using microbiological methods and genomic analysis. Bacteriophage vB_VspP_pVa5 is a N4-like podovirus with an icosahedral head measuring 85 nm in length and a short non-contractile tail. The phage had a narrow host range infecting only the bacterial host, a latent period of 30 min and a burst size of 24 virions per infected bacterium. Its genome size was 78,145 bp and genomic analysis identified 107 densely-packed genes, 40 of which could be annotated. In addition to the very large virion encapsulated DNA-dependent RNA polymerase which is the signature of the N4-like genus, an interesting feature of the novel phage is the presence of a self-splicing group I intron in the thymidylate synthase gene. A tRNAStop interrupted by a ~2.5kb open reading frame-containing area was also identified. The absence of genes related to lysogeny along with the high efficacy observed during in vitro cell lysis trials, indicate that the vB_VspP_pVa5 is a potential candidate component in a bacteriophage cocktail suitable for the biological control of V. splendidus in aquaculture.

  18. Vibrio fujianensis sp. nov., isolated from aquaculture water.

    Science.gov (United States)

    Fang, Yujie; Chen, Aiping; Dai, Hang; Huang, Ying; Kan, Biao; Wang, Duochun

    2018-02-13

    A Gram-stain-negative, facultatively anaerobic strain, designated FJ201301 T , was isolated from aquaculture water collected from Fujian province, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain FJ201301 T belonged to the genus Vibrio, formed a distinct cluster with Vibriocincinnatiensis ATCC 35912 T and shared the highest similarity with Vibriosalilacus CGMCC 1.12427 T . A 15 bp insertion found in the 16S rRNA gene was a significant marker that distinguished strain FJ201301 T from several phylogenetic neighbours (e.g. V. cincinnatiensis). Multilocus sequence analysis of eight genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; concatenated 4135 bp sequence) showed that, forming a long and independent phylogenetic branch, strain FJ201301 T clustered with V. cincinnatiensis ATCC 35912 T , Vibrioinjenensis KCTC 32233 T and Vibriometschnikovii CIP 69.14 T clearly separated from V. salilacus CGMCC 1.12427 T . Furthermore, the highest in silico DNA-DNA hybridization and average nucleotide identity values between strain FJ201301 T and the closest related species were 26.3 and 83.1 % with V. cincinnatiensis ATCC 35912 T , less than the proposed cutoff levels for species delineation, i.e. 70 and 95 %, respectively. Biochemical, sequence and genomic analysis suggested the designation of strain FJ201301 T representing a novel species of the genus Vibrio, for which the name Vibrio fujianensis sp. nov. is proposed. The type strain is FJ201301 T (=DSM 104687 T =CGMCC 1.16099 T ).

  19. Quorum Sensing Disruption in Vibrio harveyi Bacteria by Clay Materials.

    Science.gov (United States)

    Naik, Sajo P; Scholin, Jonathon; Ching, San; Chi, Fang; Herpfer, Marc

    2018-01-10

    This work describes the use of clay minerals as catalysts for the degradation of quorum sensing molecule N-(3-oxooctanoyl)-dl-homoserine lactone. Certain clay minerals as a result of their surface properties and porosity can catalytically degrade the quorum sensing molecule into smaller fragments. The disruption of quorum sensing by clay in a growing Gram-negative Vibrio harveyi bacteria culture was also studied by monitoring luminescence and population density of the bacteria, wherein quenching of bacterial quorum sensing activity was observed by means of luminescence reduction. The results of this study show that food-grade clays can be used as biocatalysts in disrupting bacterial activity in various media.

  20. Inhibitory Effect of Glycerin on Vibrio parahaemolyticus and Salmonella

    Science.gov (United States)

    Chun, Doki; Seol, Sung Yong; Tak, Ryunbin; Park, Cheong Kyu

    1972-01-01

    In a study of the effect of glycerin in transport media on Vibrio parahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of peptone or human feces in media did not reduce the inhibitory effect of glycerin. In media with 15% glycerin, viable counts of V. parahaemolyticus and Salmonella increased after 24 hr of incubation both in the presence and absence of feces. Due to the concurrent increase in the total bacterial count in the media containing feces, no enrichment effect was noted. PMID:4565633

  1. Lack of Outer Membrane Protein A Enhances the Release of Outer Membrane Vesicles and Survival of Vibrio cholerae and Suppresses Viability of Acanthamoeba castellanii

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    Soni Priya Valeru

    2014-01-01

    Full Text Available Vibrio cholerae, the causative agent of the diarrhoeal disease cholera, survives in aquatic environments. The bacterium has developed a survival strategy to grow and survive inside Acanthamoeba castellanii. It has been shown that V. cholerae expresses outer membrane proteins as virulence factors playing a role in the adherence to interacted host cells. This study examined the role of outer membrane protein A (OmpA and outer membrane vesicles (OMVs in survival of V. cholerae alone and during its interaction with A. castellanii. The results showed that an OmpA mutant of V. cholerae survived longer than wild-type V. cholerae when cultivated alone. Cocultivation with A. castellanii enhanced the survival of both bacterial strains and OmpA protein exhibited no effect on attachment, engulfment, and survival inside the amoebae. However, cocultivation of the OmpA mutant of V. cholerae decreased the viability of A. castellanii and this bacterial strain released more OMVs than wild-type V. cholerae. Surprisingly, treatment of amoeba cells with OMVs isolated from the OmpA mutant significantly decreased viable counts of the amoeba cells. In conclusion, the results might highlight a regulating rule for OmpA in survival of V. cholerae and OMVs as a potent virulence factor for this bacterium towards eukaryotes in the environment.

  2. Clinical isolates of Aeromonas veronii biovar veronii harbor a nonfunctional gene similar to the thermostable direct hemolysin-related hemolysin (trh) gene of Vibrio parahaemolyticus.

    Science.gov (United States)

    Raghunath, Pendru; Maiti, Biswajit; Shekar, Malathi; Karunasagar, Iddya; Karunasagar, Indrani

    2010-06-01

    Thermostable direct hemolysin-related hemolysin encoded by the trh gene is considered a major virulence factor in the pathogenesis of Vibrio parahaemolyticus infections. In this study, we report the presence of a trh homolog in three clinical isolates of Aeromonas veronii biovar veronii. The presence of a trh homolog in these strains of A. veronii was confirmed by PCR, followed by cloning, sequencing and colony hybridization using a digoxigenin-labelled probe. DNA sequence analysis revealed that the A. veronii trh gene had an identity of 99% and 84% to the trh1 and trh2 genes of V. parahaemolyticus, respectively. However, the expression of a trh-like gene in A. veronii could not be detected by reverse transcription PCR. Hence, the role of the gene product in the virulence of A. veronii strains is not clear. Further, these A. veronii isolates were negative for the ure gene encoding urease and the transposase gene by PCR. These genes are part of the trh gene cluster in V. parahaemolyticus. However, the presence of a trh homolog in a pathogen other than V. parahaemolyticus points to the fact that detection of the trh gene in stool samples, seafood enrichments or environmental samples does not always imply that trh-carrying V. parahaemolyticus are present.

  3. Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains.

    Science.gov (United States)

    Bonar, Emilia; Wojcik, Iwona; Jankowska, Urszula; Kedracka-Krok, Sylwia; Bukowski, Michal; Polakowska, Klaudia; Lis, Marcin W; Kosecka-Strojek, Maja; Sabat, Artur J; Dubin, Grzegorz; Friedrich, Alexander W; Miedzobrodzki, Jacek; Dubin, Adam; Wladyka, Benedykt

    2016-01-01

    Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR) and non-virulent (NVIR) phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains. Staphopain C (StpC) was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC, and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model.

  4. The Na+-Translocating NADH:Quinone Oxidoreductase Enhances Oxidative Stress in the Cytoplasm of Vibrio cholerae.

    Science.gov (United States)

    Muras, Valentin; Dogaru-Kinn, Paul; Minato, Yusuke; Häse, Claudia C; Steuber, Julia

    2016-09-01

    We searched for a source of reactive oxygen species (ROS) in the cytoplasm of the human pathogen Vibrio cholerae and addressed the mechanism of ROS formation using the dye 2',7'-dichlorofluorescein diacetate (DCFH-DA) in respiring cells. By comparing V. cholerae strains with or without active Na(+)-translocating NADH:quinone oxidoreductase (Na(+)-NQR), this respiratory sodium ion redox pump was identified as a producer of ROS in vivo The amount of cytoplasmic ROS detected in V. cholerae cells producing variants of Na(+)-NQR correlated well with rates of superoxide formation by the corresponding membrane fractions. Membranes from wild-type V. cholerae showed increased superoxide production activity (9.8 ± 0.6 μmol superoxide min(-1) mg(-1) membrane protein) compared to membranes from the mutant lacking Na(+)-NQR (0.18 ± 0.01 μmol min(-1) mg(-1)). Overexpression of plasmid-encoded Na(+)-NQR in the nqr deletion strain resulted in a drastic increase in the formation of superoxide (42.6 ± 2.8 μmol min(-1) mg(-1)). By analyzing a variant of Na(+)-NQR devoid of quinone reduction activity, we identified the reduced flavin adenine dinucleotide (FAD) cofactor of cytoplasmic NqrF subunit as the site for intracellular superoxide formation in V. cholerae The impact of superoxide formation by the Na(+)-NQR on the virulence of V. cholerae is discussed. In several studies, it was demonstrated that the Na(+)-NQR in V. cholerae affects virulence in a yet unknown manner. We identified the reduced FAD cofactor in the NADH-oxidizing NqrF subunit of the Na(+)-NQR as the site of superoxide formation in the cytoplasm of V. cholerae Our study provides the framework to understand how reactive oxygen species formed during respiration could participate in the regulated expression of virulence factors during the transition from aerobic to microaerophilic (intestinal) habitats. This hypothesis may turn out to be right for many other pathogens which, like V. cholerae, depend on the Na

  5. Characters of homogentisate oxygenase gene mutation and high clonality of the natural pigment-producing Vibrio cholerae strains

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    Diao Baowei

    2011-05-01

    Full Text Available Abstract Background Some microorganisms can produce pigments such as melanin, which has been associated with virulence in the host and with a survival advantage in the environment. In Vibrio cholerae, studies have shown that pigment-producing mutants are more virulent than the parental strain in terms of increased UV resistance, production of major virulence factors, and colonization. To date, almost all of the pigmented V. cholerae strains investigated have been induced by chemicals, culture stress, or transposon mutagenesis. However, during our cholera surveillance, some nontoxigenic serogroup O139 strains and one toxigenic O1 strain, which can produce pigment steadily under the commonly used experimental growth conditions, were obtained in different years and from different areas. The genes VC1344 to VC1347, which correspond to the El Tor strain N16961 genome and which comprise an operon in the tyrosine catabolic pathway, have been confirmed to be associated with a pigmented phenotype. In the present study, we investigated the mechanism of pigment production in these strains. Results Sequencing of the VC1344, VC1345, VC1346, and VC1347 genes in these pigmented strains suggested that a deletion mutation in the homogentisate oxygenase gene (VC1345 may be associated with the pigmented phenotype, and gene complementation confirmed the role of this gene in pigment production. An identical 15-bp deletion was found in the VC1345 gene of all six O139 pigment-producing strains examined, and a 10-bp deletion was found in the VC1345 gene of the O1 strain. Strict sequence conservation in the VC1344 gene but higher variance in the other three genes of this operon were observed, indicating the different stress response functions of these genes in environmental adaption and selection. On the basis of pulsed-field gel electrophoresis typing, the pigment-producing O139 strains showed high clonality, even though they were isolated in different years and from

  6. New insights into Oculina patagonica coral diseases and their associated Vibrio spp. communities.

    Science.gov (United States)

    Rubio-Portillo, Esther; Yarza, Pablo; Peñalver, Cindy; Ramos-Esplá, Alfonso A; Antón, Josefa

    2014-09-01

    Bleaching of Oculina patagonica has been extensively studied in the Eastern Mediterranean Sea, although no studies have been carried out in the Western basin. In 1996 Vibrio mediterranei was reported as the causative agent of bleaching in O. patagonica but it has not been related to bleached or healthy corals since 2003, suggesting that it was no longer involved in bleaching of O. patagonica. In an attempt to clarify the relationship between Vibrio spp., seawater temperature and coral diseases, as well as to investigate the putative differences between Eastern and Western Mediterranean basins, we have analysed the seasonal patterns of the culturable Vibrio spp. assemblages associated with healthy and diseased O. patagonica colonies. Two sampling points located in the Spanish Mediterranean coast were chosen for this study: Alicante Harbour and the Marine Reserve of Tabarca. A complex and dynamic assemblage of Vibrio spp. was present in O. patagonica along the whole year and under different environmental conditions and coral health status. While some Vibrio spp. were detected all year around in corals, the known pathogens V. mediteranei and V. coralliilyticus were only present in diseased specimens. The pathogenic potential of these bacteria was studied by experimental infection under laboratory conditions. Both vibrios caused diseased signs from 24 °C, being higher and faster at 28 °C. Unexpectedly, the co-inoculation of these two Vibrio species seemed to have a synergistic pathogenic effect over O. patagonica, as disease signs were readily observed at temperatures at which bleaching is not normally observed.

  7. Identification and Initial Characterization of Prophages in Vibrio campbellii.

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    Nicola Lorenz

    Full Text Available Phages are bacteria targeting viruses and represent the most abundant biological entities on earth. Marine environments are exceptionally rich in bacteriophages, harboring a total of 4x1030 viruses. Nevertheless, marine phages remain poorly characterized. Here we describe the identification of intact prophage sequences in the genome of the marine γ-proteobacterium Vibrio campbellii ATCC BAA-1116 (formerly known as V. harveyi ATCC BAA-1116, which presumably belong to the family of Myoviridae. One prophage was found on chromosome I and shows significant similarities to the previously identified phage ΦHAP-1. The second prophage region is located on chromosome II and is related to Vibrio phage kappa. Exposure of V. campbellii to mitomycin C induced the lytic cycle of two morphologically distinct phages and, as expected, extracellular DNA from induced cultures was found to be specifically enriched for the sequences previously identified as prophage regions. Heat stress (50°C, 30 min was also found to induce phage release in V. campbellii. Notably, promoter activity of two representative phage genes indicated heterogeneous phage induction within the population.

  8. Vibrio cholerae Represses Polysaccharide Synthesis To Promote Motility in Mucosa

    Science.gov (United States)

    Liu, Zhenyu; Wang, Yuning; Liu, Shengyan; Sheng, Ying; Rueggeberg, Karl-Gustav; Wang, Hui; Li, Jie; Gu, Frank X.; Zhong, Zengtao; Kan, Biao

    2015-01-01

    The viscoelastic mucus layer of gastrointestinal tracts is a host defense barrier that a successful enteric pathogen, such as Vibrio cholerae, must circumvent. V. cholerae, the causative agent of cholera, is able to penetrate the mucosa and colonize the epithelial surface of the small intestine. In this study, we found that mucin, the major component of mucus, promoted V. cholerae movement on semisolid medium and in liquid medium. A genome-wide screen revealed that Vibrio polysaccharide (VPS) production was inversely correlated with mucin-enhanced motility. Mucin adhesion assays indicated that VPS bound to mucin. Moreover, we found that vps expression was reduced upon exposure to mucin. In an infant mouse colonization model, mutants that overexpressed VPS colonized less effectively than wild-type strains in more distal intestinal regions. These results suggest that V. cholerae is able to sense mucosal signals and modulate vps expression accordingly so as to promote fast motion in mucus, thus allowing for rapid spread throughout the intestines. PMID:25561707

  9. Invariant recognition of polychromatic images of Vibrio cholerae 01

    Science.gov (United States)

    Alvarez-Borrego, Josue; Mourino-Perez, Rosa R.; Cristobal, Gabriel; Pech-Pacheco, Jose L.

    2002-04-01

    Cholera is an acute intestinal infectious disease. It has claimed many lives throughout history, and it continues to be a global health threat. Cholera is considered one of the most important emergence diseases due its relation with global climate changes. Automated methods such as optical systems represent a new trend to make more accurate measurements of the presence and quantity of this microorganism in its natural environment. Automatic systems eliminate observer bias and reduce the analysis time. We evaluate the utility of coherent optical systems with invariant correlation for the recognition of Vibrio cholerae O1. Images of scenes are recorded with a CCD camera and decomposed in three RGB channels. A numeric simulation is developed to identify the bacteria in the different samples through an invariant correlation technique. There is no variation when we repeat the correlation and the variation between images correlation is minimum. The position-, scale-, and rotation-invariant recognition is made with a scale transform through the Mellin transform. The algorithm to recognize Vibrio cholerae O1 is the presence of correlation peaks in the green channel output and their absence in red and blue channels. The discrimination criterion is the presence of correlation peaks in red, green, and blue channels.

  10. Vibrio fischeri-derived outer membrane vesicles trigger host development.

    Science.gov (United States)

    Aschtgen, Marie-Stephanie; Wetzel, Keith; Goldman, William; McFall-Ngai, Margaret; Ruby, Edward

    2016-04-01

    Outer membrane vesicles (OMV) are critical elements in many host-cell/microbe interactions. Previous studies of the symbiotic association between Euprymna scolopes and Vibrio fischeri had shown that within 12 h of colonizing crypts deep within the squid's light organ, the symbionts trigger an irreversible programme of tissue development in the host. Here, we report that OMV produced by V. fischeri are powerful contributors to this process. The first detectable host response to the OMV is an increased trafficking of macrophage-like cells called haemocytes into surface epithelial tissues. We showed that exposing the squid to other Vibrio species fails to induce this trafficking; however, addition of a high concentration of their OMV, which can diffuse into the crypts, does. We also provide evidence that tracheal cytotoxin released by the symbionts, which can induce haemocyte trafficking, is not part of the OMV cargo, suggesting two distinct mechanisms to induce the same morphogenesis event. By manipulating the timing and localization of OMV signal delivery, we showed that haemocyte trafficking is fully induced only when V. fischeri, the sole species able to reach and grow in the crypts, succeeds in establishing a sustained colonization. Further, our data suggest that the host's detection of OMV serves as a symbiotic checkpoint prior to inducing irreversible morphogenesis. © 2015 John Wiley & Sons Ltd.

  11. Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

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    Afzali H.MD,

    2016-03-01

    Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

  12. Experimental infection with different bacterial strains in larvae and juvenile Litopenaeus vannamei reared in Santa Catarina State, Brazil = Infecção experimental em larvas e juvenis de Litopaenaeus vannamei cultivados no Estado de Santa Catarina, Brasil

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    Celso Carlos Buglione

    2010-07-01

    Full Text Available This study evaluated the pathogenic characteristics of bacteria isolated from Litopenaeus vannamei during an outbreak at the Laboratory of Marine Shrimp, UFSC, Santa Catarina State, Brazil. Their virulence potential in larvae and juvenile shrimp and theeffects on the total haemocyte count, phenoloxidase activity and serum agglutinate titre were examined after experimental infection. Bacterial strains were isolated from larvae and adult shrimps, identified by the AP120E biochemical system as: two strains of Vibrioalginolyticus, three of Aeromonas salmonicida and one of Pasteurella multocida sp. and Pasteurella sp. All the bacterial strains isolated in this study caused mortality in shrimp. One strain of V. alginolyticus was responsible for 97.3 and 88.7% mortality in larvae and juvenil shrimps, respectively. The shrimp immunological system was influenced by experimental infection with V. alginolyticus. Decrease in the total haemocyte count and increase in the phenoloxidase activity and the serum agglutinate titre (p Este estudo avaliou as características patogênicas de cepas de bactérias isoladas de Litopenaeus vannamei durante surto de mortalidade no Laboratório de Camarões Marinhos, UFSC, Estado de Santa Catarina, Brasil. Seu potencial de virulência em larvas e juvenis de camarão marinho e os efeitos sobre a contagem total de hemócito, atividade de fenoloxidase e título aglutinante do soro foramavaliados após infecção experimental. As cepas bacterianas foram isoladas de larvas e de camarões adultos e identificadas bioquimicamente pelo sistema API20E como: duas cepas de Vibrio alginolyticus, três de Aeromonas salmonicida e uma de Pasteurella sp. e P. multocida. Todas as cepas isoladas provocaram mortalidade em L. vannamei, e uma de V. alginolyticus resultou em mortalidade de 97,3 e 88,7% para larvas e juvenis de camarões, respectivamente. O sistema imunológico dos camarões juvenis sofreu influência da infecção experimental

  13. Vibrio japonicus sp. nov., a novel member of the Nereis clade in the genus Vibrio isolated from the coast of Japan.

    Science.gov (United States)

    Doi, Hiroyasu; Osawa, Ikuko; Adachi, Hayamitsu; Kawada, Manabu

    2017-01-01

    A novel Vibrio strain, JCM 31412T, was isolated from seawater collected from the Inland Sea (Setonaikai), Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412T showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546T, 98.2% identity), V. harveyi (NBRC 15634T, 98.2%), V. caribbeanicus (ATCC BAA-2122T, 97.8%) and V. proteolyticus (NBRC 13287T, 97.8%). The G+C content of strain JCM 31412T DNA was 46.8%. Multi-locus sequence analysis (MLSA) of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp) further clustered strain JCM 31412T in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412T differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C12:03OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412T from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412T was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412T (= LMG 29636T = ATCC TSD-62T) as the type strain.

  14. Vibrio japonicus sp. nov., a novel member of the Nereis clade in the genus Vibrio isolated from the coast of Japan.

    Directory of Open Access Journals (Sweden)

    Hiroyasu Doi

    Full Text Available A novel Vibrio strain, JCM 31412T, was isolated from seawater collected from the Inland Sea (Setonaikai, Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412T showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546T, 98.2% identity, V. harveyi (NBRC 15634T, 98.2%, V. caribbeanicus (ATCC BAA-2122T, 97.8% and V. proteolyticus (NBRC 13287T, 97.8%. The G+C content of strain JCM 31412T DNA was 46.8%. Multi-locus sequence analysis (MLSA of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp further clustered strain JCM 31412T in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412T differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C12:03OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412T from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412T was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412T (= LMG 29636T = ATCC TSD-62T as the type strain.

  15. Salmonella promotes virulence by repressing cellulose production.

    Science.gov (United States)

    Pontes, Mauricio H; Lee, Eun-Jin; Choi, Jeongjoon; Groisman, Eduardo A

    2015-04-21

    Cellulose is the most abundant organic polymer on Earth. In bacteria, cellulose confers protection against environmental insults and is a constituent of biofilms typically formed on abiotic surfaces. We report that, surprisingly, Salmonella enterica serovar Typhimurium makes cellulose when inside macrophages. We determine that preventing cellulose synthesis increases virulence, whereas stimulation of cellulose synthesis inside macrophages decreases virulence. An attenuated mutant lacking the mgtC gene exhibited increased cellulose levels due to increased expression of the cellulose synthase gene bcsA and of cyclic diguanylate, the allosteric activator of the BcsA protein. Inactivation of bcsA restored wild-type virulence to the Salmonella mgtC mutant, but not to other attenuated mutants displaying a wild-type phenotype regarding cellulose. Our findings indicate that a virulence determinant can promote pathogenicity by repressing a pathogen's antivirulence trait. Moreover, they suggest that controlling antivirulence traits increases long-term pathogen fitness by mediating a trade-off between acute virulence and transmission.

  16. Salmonella promotes virulence by repressing cellulose production

    Science.gov (United States)

    Pontes, Mauricio H.; Lee, Eun-Jin; Choi, Jeongjoon; Groisman, Eduardo A.

    2015-01-01

    Cellulose is the most abundant organic polymer on Earth. In bacteria, cellulose confers protection against environmental insults and is a constituent of biofilms typically formed on abiotic surfaces. We report that, surprisingly, Salmonella enterica serovar Typhimurium makes cellulose when inside macrophages. We determine that preventing cellulose synthesis increases virulence, whereas stimulation of cellulose synthesis inside macrophages decreases virulence. An attenuated mutant lacking the mgtC gene exhibited increased cellulose levels due to increased expression of the cellulose synthase gene bcsA and of cyclic diguanylate, the allosteric activator of the BcsA protein. Inactivation of bcsA restored wild-type virulence to the Salmonella mgtC mutant, but not to other attenuated mutants displaying a wild-type phenotype regarding cellulose. Our findings indicate that a virulence determinant can promote pathogenicity by repressing a pathogen's antivirulence trait. Moreover, they suggest that controlling antivirulence traits increases long-term pathogen fitness by mediating a trade-off between acute virulence and transmission. PMID:25848006

  17. Antimicrobial effect of dietary oregano essential oil against Vibrio bacteria in shrimps

    Directory of Open Access Journals (Sweden)

    Gracia-Valenzuela M.H.

    2014-01-01

    Full Text Available The effect of dietary oregano essential oils on the growth of Vibrio bacteria in shrimps was evaluated. Shrimps were fed: (i food with oregano oil with a high level of thymol; (ii food with oregano oil with a high level of carvacrol, and (iii food without oregano oil (the control. The animals were infected by three species of Vibrio (vulnificus, parahaemolyticus and cholerae. The microbial counts of Vibrio species were significantly lower (p <0.05 in tissues from animals whose food was supplemented with oregano oil. We concluded that dietary supplementation of shrimps with oregano oil provides antimicrobial activity into the body of the penaeids.

  18. Amplification of tlh gene in other Vibrionaceae specie by specie-specific multiplex PCR of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Romina Yáñez

    2015-11-01

    Conclusions: Surveillance of V. parahaemolyticus using tlh primers can be imprecise because amplification of a V. parahaemolyticus specific marker in V. alginolyticus and other related strains occurs. This situation complicates potentially the estimation of bacterial load in seafood, because do not ensure the correct identification of V. parahaemolyticus when his load is low. Additionally, it could complicate the tracking of outbreaks of V. parahaemolyticus infections, considering the genetic markers used would not be specie-specific.

  19. Virulence factors of the Mycobacterium tuberculosis complex

    Science.gov (United States)

    Forrellad, Marina A.; Klepp, Laura I.; Gioffré, Andrea; Sabio y García, Julia; Morbidoni, Hector R.; Santangelo, María de la Paz; Cataldi, Angel A.; Bigi, Fabiana

    2013-01-01

    The Mycobacterium tuberculosis complex (MTBC) consists of closely related species that cause tuberculosis in both humans and animals. This illness, still today, remains to be one of the leading causes of morbidity and mortality throughout the world. The mycobacteria enter the host by air, and, once in the lungs, are phagocytated by macrophages. This may lead to the rapid elimination of the bacillus or to the triggering of an active tuberculosis infection. A large number of different virulence factors have evolved in MTBC members as a response to the host immune reaction. The aim of this review is to describe the bacterial genes/proteins that are essential for the virulence of MTBC species, and that have been demonstrated in an in vivo model of infection. Knowledge of MTBC virulence factors is essential for the development of new vaccines and drugs to help manage the disease toward an increasingly more tuberculosis-free world. PMID:23076359

  20. Glucose starvation boosts Entamoeba histolytica virulence.

    Directory of Open Access Journals (Sweden)

    Ayala Tovy

    2011-08-01

    Full Text Available The unicellular parasite, Entamoeba histolytica, is exposed to numerous adverse conditions, such as nutrient deprivation, during its life cycle stages in the human host. In the present study, we examined whether the parasite virulence could be influenced by glucose starvation (GS. The migratory behaviour of the parasite and its capability to kill mammalian cells and to lyse erythrocytes is strongly enhanced following GS. In order to gain insights into the mechanism underlying the GS boosting effects on virulence, we analyzed differences in protein expression levels in control and glucose-starved trophozoites, by quantitative proteomic analysis. We observed that upstream regulatory element 3-binding protein (URE3-BP, a transcription factor that modulates E.histolytica virulence, and the lysine-rich protein 1 (KRiP1 which is induced during liver abscess development, are upregulated by GS. We also analyzed E. histolytica membrane fractions and noticed that the Gal/GalNAc lectin light subunit LgL1 is up-regulated by GS. Surprisingly, amoebapore A (Ap-A and cysteine proteinase A5 (CP-A5, two important E. histolytica virulence factors, were strongly down-regulated by GS. While the boosting effect of GS on E. histolytica virulence was conserved in strains silenced for Ap-A and CP-A5, it was lost in LgL1 and in KRiP1 down-regulated strains. These data emphasize the unexpected role of GS in the modulation of E.histolytica virulence and the involvement of KRiP1 and Lgl1 in this phenomenon.

  1. The high prevalence of pathogenic Vibrio harveyi with multiple antibiotic resistance in scale drop and muscle necrosis disease of the hybrid grouper, Epinephelus fuscoguttatus (♀) × E. lanceolatus (♂), in China.

    Science.gov (United States)

    Zhu, Z M; Dong, C F; Weng, S P; He, J G

    2017-11-28

    Scale drop and muscle necrosis disease with high mortality widely occurred recently in the hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂), a crucial cultured marine fish species in China. In this study, 30 Harveyi clade isolates of 27 Vibrio harveyi strains were isolated from diseased hybrid groupers in the south-east and north-east coastal areas of China. A total of 22 V. harveyi strains were determined to be pathogenic, and most challenged fish died within 2 days of infection; surviving individuals exhibited scale drop and deep dermal lesions as naturally diseased fish. Although five typical virulence genes, including luxR, toxRVh , chiA, serine protease and vhh widely existed in V. harveyi, no obvious correlation was established between virulent strains and virulence genes harboured in them. Furthermore, multiple antibiotic resistance was widely exhibited in Harveyi clade strains, particularly for penicillins, polypeptides, lincomycins, acetylspiramycin, streptomycin, metronidazole and bacitracin. And the multiple antibiotic resistance indices were gradually decreased from southern to northern areas of China. This study demonstrated that the pathogenic V. harveyi with multiple antibiotic resistance is highly prevalent in hybrid grouper in China, which requires particular attention. © 2017 John Wiley & Sons Ltd.

  2. Phylodynamic analysis of clinical and environmental Vibrio cholerae isolates from Haiti reveals diversification driven by positive selection.

    Science.gov (United States)

    Azarian, Taj; Ali, Afsar; Johnson, Judith A; Mohr, David; Prosperi, Mattia; Veras, Nazle M; Jubair, Mohammed; Strickland, Samantha L; Rashid, Mohammad H; Alam, Meer T; Weppelmann, Thomas A; Katz, Lee S; Tarr, Cheryl L; Colwell, Rita R; Morris, J Glenn; Salemi, Marco

    2014-12-23

    Phylodynamic analysis of genome-wide single-nucleotide polymorphism (SNP) data is a powerful tool to investigate underlying evolutionary processes of bacterial epidemics. The method was applied to investigate a collection of 65 clinical and environmental isolates of Vibrio cholerae from Haiti collected between 2010 and 2012. Characterization of isolates recovered from environmental samples identified a total of four toxigenic V. cholerae O1 isolates, four non-O1/O139 isolates, and a novel nontoxigenic V. cholerae O1 isolate with the classical tcpA gene. Phylogenies of strains were inferred from genome-wide SNPs using coalescent-based demographic models within a Bayesian framework. A close phylogenetic relationship between clinical and environmental toxigenic V. cholerae O1 strains was observed. As cholera spread throughout Haiti between October 2010 and August 2012, the population size initially increased and then fluctuated over time. Selection analysis along internal branches of the phylogeny showed a steady accumulation of synonymous substitutions and a progressive increase of nonsynonymous substitutions over time, suggesting diversification likely was driven by positive selection. Short-term accumulation of nonsynonymous substitutions driven by selection may have significant implications for virulence, transmission dynamics, and even vaccine efficacy. Cholera, a dehydrating diarrheal disease caused by toxigenic strains of the bacterium Vibrio cholerae, emerged in 2010 in Haiti, a country where there were no available records on cholera over the past 100 years. While devastating in terms of morbidity and mortality, the outbreak provided a unique opportunity to study the evolutionary dynamics of V. cholerae and its environmental presence. The present study expands on previous work and provides an in-depth phylodynamic analysis inferred from genome-wide single nucleotide polymorphisms of clinical and environmental strains from dispersed geographic settings in

  3. Cholera outbreaks (2012) in three districts of Nepal reveal clonal transmission of multi-drug resistant Vibrio cholerae O1.

    Science.gov (United States)

    Dixit, Sameer M; Johura, Fatema-Tuz; Manandhar, Sulochana; Sadique, Abdus; Rajbhandari, Rajesh M; Mannan, Shahnewaj B; Rashid, Mahamud-Ur; Islam, Saiful; Karmacharya, Dibesh; Watanabe, Haruo; Sack, R Bradley; Cravioto, Alejandro; Alam, Munirul

    2014-07-15

    Although endemic cholera causes significant morbidity and mortality each year in Nepal, lack of information about the causal bacterium often hinders cholera intervention and prevention. In 2012, diarrheal outbreaks affected three districts of Nepal with confirmed cases of mortality. This study was designed to understand the drug response patterns, source, and transmission of Vibrio cholerae associated with 2012 cholera outbreaks in Nepal. V. cholerae (n = 28) isolated from 2012 diarrhea outbreaks {n = 22; Kathmandu (n = 12), Doti (n = 9), Bajhang (n = 1)}, and surface water (n = 6; Kathmandu) were tested for antimicrobial response. Virulence properties and DNA fingerprinting of the strains were determined by multi-locus genetic screening employing polymerase chain reaction, DNA sequencing, and pulsed-field gel electrophoresis (PFGE). All V. cholerae strains isolated from patients and surface water were confirmed to be toxigenic, belonging to serogroup O1, Ogawa serotype, biotype El Tor, and possessed classical biotype cholera toxin (CTX). Double-mismatch amplification mutation assay (DMAMA)-PCR revealed the V. cholerae strains to possess the B-7 allele of ctx subunit B. DNA sequencing of tcpA revealed a point mutation at amino acid position 64 (N → S) while the ctxAB promoter revealed four copies of the tandem heptamer repeat sequence 5'-TTTTGAT-3'. V. cholerae possessed all the ORFs of the Vibrio seventh pandemic island (VSP)-I but lacked the ORFs 498-511 of VSP-II. All strains were multidrug resistant with resistance to trimethoprim-sulfamethoxazole (SXT), nalidixic acid (NA), and streptomycin (S); all carried the SXT genetic element. DNA sequencing and deduced amino acid sequence of gyrA and parC of the NAR strains (n = 4) revealed point mutations at amino acid positions 83 (S → I), and 85 (S → L), respectively. Similar PFGE (NotI) pattern revealed the Nepalese V. cholerae to be clonal, and related closely with V. cholerae associated with cholera in

  4. Analysis of the SOS response of Vibrio and other bacteria with multiple chromosomes

    Directory of Open Access Journals (Sweden)

    Sanchez-Alberola Neus

    2012-02-01

    Full Text Available Abstract Background The SOS response is a well-known regulatory network present in most bacteria and aimed at addressing DNA damage. It has also been linked extensively to stress-induced mutagenesis, virulence and the emergence and dissemination of antibiotic resistance determinants. Recently, the SOS response has been shown to regulate the activity of integrases in the chromosomal superintegrons of the Vibrionaceae, which encompasses a wide range of pathogenic species harboring multiple chromosomes. Here we combine in silico and in vitro techniques to perform a comparative genomics analysis of the SOS regulon in the Vibrionaceae, and we extend the methodology to map this transcriptional network in other bacterial species harboring multiple chromosomes. Results Our analysis provides the first comprehensive description of the SOS response in a family (Vibrionaceae that includes major human pathogens. It also identifies several previously unreported members of the SOS transcriptional network, including two proteins of unknown function. The analysis of the SOS response in other bacterial species with multiple chromosomes uncovers additional regulon members and reveals that there is a conserved core of SOS genes, and that specialized additions to this basic network take place in different phylogenetic groups. Our results also indicate that across all groups the main elements of the SOS response are always found in the large chromosome, whereas specialized additions are found in the smaller chromosomes and plasmids. Conclusions Our findings confirm that the SOS response of the Vibrionaceae is strongly linked with pathogenicity and dissemination of antibiotic resistance, and suggest that the characterization of the newly identified members of this regulon could provide key insights into the pathogenesis of Vibrio. The persistent location of key SOS genes in the large chromosome across several bacterial groups confirms that the SOS response plays an

  5. The Vaccine Candidate Vibrio cholerae 638 Is Protective against Cholera in Healthy Volunteers

    Science.gov (United States)

    García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L.; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

    2005-01-01

    Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXΦ prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 109 CFU of freshly harvested 638 buffered with 1.3% NaHCO3, while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 109 CFU of ΔCTXΦ attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 × 105 CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO3. Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (109 CFU) of strain

  6. Characterization of trh2 Harbouring Vibrio parahaemolyticus Strains Isolated in Germany

    Science.gov (United States)

    Bechlars, Silke; Jäckel, Claudia; Diescher, Susanne; Wüstenhagen, Doreen A.; Kubick, Stefan; Dieckmann, Ralf; Strauch, Eckhard

    2015-01-01

    Background Vibrio parahaemolyticus is a recognized human enteropathogen. Thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) as well as the type III secretion system 2 (T3SS2) are considered as major virulence factors. As tdh positive strains are not detected in coastal waters of Germany, we focused on the characterization of trh positive strains, which were isolated from mussels, seawater and patients in Germany. Results Ten trh harbouring V. parahaemolyticus strains from Germany were compared to twenty-one trh positive strains from other countries. The complete trh sequences revealed clustering into three different types: trh1 and trh2 genes and a pseudogene Ψtrh. All German isolates possessed alleles of the trh2 gene. MLST analysis indicated a close relationship to Norwegian isolates suggesting that these strains belong to the autochthonous microflora of Northern Europe seawaters. Strains carrying the pseudogene Ψtrh were negative for T3SS2β effector vopC. Transcription of trh and vopC genes was analyzed under different growth conditions. Trh2 gene expression was not altered by bile while trh1 genes were inducible. VopC could be induced by urea in trh2 bearing strains. Most trh1 carrying strains were hemolytic against sheep erythrocytes while all trh2 positive strains did not show any hemolytic activity. TRH variants were synthesized in a prokaryotic cell-free system and their hemolytic activity was analyzed. TRH1 was active against sheep erythrocytes while TRH2 variants were not active at all. Conclusion Our study reveals a high diversity among trh positive V. parahaemolyticus strains. The function of TRH2 hemolysins and the role of the pseudogene Ψtrh as pathogenicity factors are questionable. To assess the pathogenic potential of V. parahaemolyticus strains a differentiation of trh variants and the detection of T3SS2β components like vopC would improve the V. parahaemolyticus diagnostics and could lead to a refinement of the risk

  7. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    The occurrence of Vibrio cholerae in water, sediment and copepods was studied over a wide range of salinity using conventional and polymerase chain reaction (PCR) techniques in the Cochin backwaters. V. cholerae occurred either as culturable or non-culturable...

  8. Competitive Survival of Escherichia coli, Vibrio cholerae, Salmonella typhimurium and Shigella dysenteriae in Riverbed Sediments

    CSIR Research Space (South Africa)

    Abia, AL

    2016-11-01

    Full Text Available investigated the survival of Escherichia coli, Salmonella enterica ser. Typhimurium, Vibrio cholerae and Shigella dysenteriae in riverbed sediments of the Apies River. Experiments were performed in flow chambers containing three sediment types and connected...

  9. Corrosion of mild steel and stainless steel by marine Vibrio sp.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wagh, A.B.

    Microbially induced corrosion (MIC) of stainless steel and mild steel coupons exposed to media with and without a bacterial culture Vibrio sp. was studied using Scanning Electron Microscope (SEM). Pitting type of corrosion was noticed which was more...

  10. Vibrio cholerae Detection in Water and Wastewater by Polymerase Chain Reaction Assay

    Directory of Open Access Journals (Sweden)

    Behnaz Barzamini

    2014-11-01

    Full Text Available Background: Vibrio cholerae is a significant human pathogen worldwide and annually causes some cases of deaths. Contaminated water plays an important role in transmission of this pathogen, which indicates the importance of early diagnosis. Objectives: The current study aimed to perform Polymerase Chain Reaction (PCR on water and wastewater samples to determine the detection limit for Vibrio cholerae. Materials and Methods: PCR was performed on the DNA extracted from Vibrio cholerae of the contaminated water and wastewater using ctxA gene specific primers. The accuracy of PCR method to detect these bacteria was also assessed. Results: The result of PCR performed on the extracted DNA showed a specific 241 base pair band. The limit of bacterial detection for water and wastewater were 40 cfu/mL and 81 cfu/mL, respectively. Conclusions: In the current study, PCR performance using the ctxA gene specific primers to detect Vibrio cholerae was found highly accurate and specific.

  11. Complete Genome Sequence of Vibrio fischeri: A Symbiotic Bacterium with Pathogenic Congeners

    National Research Council Canada - National Science Library

    E. G. Ruby; M. Urbanowski; J. Campbell; A. Dunn; M. Faini; R. Gunsalus; P. Lostroh; C. Lupp; J. McCann; D. Millikan; A. Schaefer; E. Stabb; A. Stevens; K. Visick; C. Whistler; E. P. Greenberg

    2005-01-01

    Vibrio fischeri belongs to the Vibrionaceae, a large family of marine γ-proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue...

  12. Global discovery of colonization determinants in the squid symbiont Vibrio fischeri

    National Research Council Canada - National Science Library

    John F. Brooks; Mattias C. Gyllborg; David C. Cronin; Sarah J. Quillin; Celeste A. Mallama; Randi Foxall; Cheryl Whistler; Andrew L. Goodman; Mark J. Mandel

    2014-01-01

    .... To understand the molecular determinants of microbiota selection, we examined colonization of a simplified model in which the light organ of Euprymna scolopes squid is colonized exclusively by Vibrio fischeri bacteria...

  13. Genome sequence of vibrio cholerae G4222, a South African clinical isolate

    CSIR Research Space (South Africa)

    Le Rouw, Wouter J

    2013-03-01

    Full Text Available Vibrio cholerae, a Gram-negative pathogen autochthonous to the aquatic environment, is the causative agent of cholera. Here, we report the complete genome sequence of V. cholerae G4222, a clinical isolate from South Africa....

  14. Multiple Antibiotic Resistances of Vibrio Isolates from Coastal and Brackish Water Areas

    OpenAIRE

    S. Manjusha; G. B. Sarita; K. K. Elyas; Chandrasekaran, M.

    2005-01-01

    An experiment was designed to assess the occurrence of multiple antibiotic resistances in Vibrio spp. from different (brackish and marine) environments. Water samples from nine marine landing sites and two coastal inland aquaculture farms were screened for the Vibrio spp. and assessed their resistance to twenty-two different antibiotics, which are commonly encountered in the aquatic ecosystem. Tissue samples (shrimp, mussel and sepia) were tested from the sampling site wit...

  15. Identification and Characterization of a Putative Manganese Export Protein in Vibrio cholerae

    OpenAIRE

    Fisher, Carolyn R.; Wyckoff, Elizabeth E.; Peng, Eric D.; Payne, Shelley M.

    2016-01-01

    Manganese plays an important role in the cellular physiology and metabolism of bacterial species, including the human pathogen Vibrio cholerae. The intracellular level of manganese ions is controlled through coordinated regulation of the import and export of this element. We have identified a putative manganese exporter (VC0022), named mneA (manganese exporter A), which is highly conserved among Vibrio spp. An mneA mutant exhibited sensitivity to manganese but not to other cations. Under high...

  16. Oligotyping reveals community level habitat selection within the genus Vibrio

    Directory of Open Access Journals (Sweden)

    Victor Thomas Schmidt

    2014-11-01

    Full Text Available The genus Vibrio is a metabolically and genetically diverse group of facultative anaerobic Bacteria, common in aquatic environments and marine hosts. The genus contains several species of importance to human health and aquaculture, including the causative agents of human cholera and fish vibriosis. Vibrios display a wide variety of known life histories, from opportunistic pathogens to long-standing symbioses with individual host species. Studying Vibrio ecology has been challenging as individual species often display a wide range of habitat preferences, and groups of vibrios can act as socially cohesive groups. Although strong associations with salinity, temperature and other environmental variables have been established, the degree of habitat or host specificity at both the individual and community levels is unknown. Here we use oligotyping analyses in combination with a large collection of existing Vibrio 16S ribosomal RNA (rRNA gene sequence data to reveal patterns of Vibrio ecology across a wide range of environmental, host, and abiotic substrate associated habitats. Our data show that individual taxa often display a wide range of habitat preferences yet tend to be highly abundant in either substrate-associated or free-living environments. Our analyses show that Vibrio communities share considerable overlap between two distinct hosts (i.e., sponge and fish yet are distinct from the abiotic plastic substrates. Lastly, evidence for habitat specificity at the community level exists in some habitats, despite considerable stochasticity in others. In addition to providing insights into Vibrio ecology across a broad range of habitats, our study shows the utility of oligotyping as a facile, high-throughput and unbiased method for large scale analyses of publicly available sequence data repositories and suggests its wide application could greatly extend the range of possibilities to explore microbial ecology.

  17. Ocean warming and spread of pathogenic vibrios in the aquatic environment.

    Science.gov (United States)

    Vezzulli, Luigi; Colwell, Rita R; Pruzzo, Carla

    2013-05-01

    Vibrios are among the most common bacteria that inhabit surface waters throughout the world and are responsible for a number of severe infections both in humans and animals. Several reports recently showed that human Vibrio illnesses are increasing worldwide including fatal acute diarrheal diseases, such as cholera, gastroenteritis, wound infections, and septicemia. Many scientists believe this increase may be associated with global warming and rise in sea surface temperature (SST), although not enough evidence is available to support a causal link between emergence of Vibrio infections and climate warming. The effect of increased SST in promoting spread of vibrios in coastal and brackish waters is considered a causal factor explaining this trend. Field and laboratory studies carried out over the past 40 years supported this hypothesis, clearly showing temperature promotes Vibrio growth and persistence in the aquatic environment. Most recently, a long-term retrospective microbiological study carried out in the coastal waters of the southern North Sea provided the first experimental evidence for a positive and significant relationship between SST and Vibrio occurrence over a multidecadal time scale. As a future challenge, macroecological studies of the effects of ocean warming on Vibrio persistence and spread in the aquatic environment over large spatial and temporal scales would conclusively support evidence acquired to date combined with studies of the impact of global warming on epidemiologically relevant variables, such as host susceptibility and exposure. Assessing a causal link between ongoing climate change and enhanced growth and spread of vibrios and related illness is expected to improve forecast and mitigate future outbreaks associated with these pathogens.

  18. Acute Otitis due to Vibrio fluvialis after Swimming

    Directory of Open Access Journals (Sweden)

    Ping-Jen Chen

    2012-01-01

    Full Text Available A 40-year-old female presented with purulent exudate through the left auditive duct and pain in the left ear region, which intensified during mastication. After collection of the pus from the left ear lesion, amoxicillin-clavulanic acid for seven days was prescribed for a presumed diagnosis of acute otitis. Four days later, the pus culture grew V. fluvialis which is further identified by API 20E identification system (bioMérieux. Following the successful completion of a course of antibiotics, the patient recovered completely and without complication. To the best of our knowledge, this is the first case of Vibrio fluvialis otitis after swimming in an immunocompetent patient.

  19. Shedding light on bioluminescence regulation in Vibrio fischeri.

    Science.gov (United States)

    Miyashiro, Tim; Ruby, Edward G

    2012-06-01

    The bioluminescence emitted by the marine bacterium Vibrio fischeri is a particularly striking result of individual microbial cells co-ordinating a group behaviour. The genes responsible for light production are principally regulated by the LuxR-LuxI quorum-sensing system. In addition to LuxR-LuxI, numerous other genetic elements and environmental conditions control bioluminescence production. Efforts to mathematically model the LuxR-LuxI system are providing insight into the dynamics of this autoinduction behaviour. The Hawaiian squid Euprymna scolopes forms a natural symbiosis with V. fischeri, and utilizes the symbiont-derived bioluminescence for certain nocturnal behaviours, such as counterillumination. Recent work suggests that the tissue with which V. fischeri associates not only can detect bioluminescence but may also use this light to monitor the V. fischeri population. © 2012 Blackwell Publishing Ltd.

  20. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

    Science.gov (United States)

    Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

    2013-01-01

    It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

  1. Comparative Genomics of Vibrio cholerae from Haiti, Asia, and Africa

    Science.gov (United States)

    Reimer, Aleisha R.; Van Domselaar, Gary; Stroika, Steven; Walker, Matthew; Kent, Heather; Tarr, Cheryl; Talkington, Deborah; Rowe, Lori; Olsen-Rasmussen, Melissa; Frace, Michael; Sammons, Scott; Dahourou, Georges Anicet; Boncy, Jacques; Smith, Anthony M.; Mabon, Philip; Petkau, Aaron; Graham, Morag; Gilmour, Matthew W.

    2011-01-01

    Cholera was absent from the island of Hispaniola at least a century before an outbreak that began in Haiti in the fall of 2010. Pulsed-field gel electrophoresis (PFGE) analysis of clinical isolates from the Haiti outbreak and recent global travelers returning to the United States showed indistinguishable PFGE fingerprints. To better explore the genetic ancestry of the Haiti outbreak strain, we acquired 23 whole-genome Vibrio cholerae sequences: 9 isolates obtained in Haiti or the Dominican Republic, 12 PFGE pattern-matched isolates linked to Asia or Africa, and 2 nonmatched outliers from the Western Hemisphere. Phylogenies for whole-genome sequences and core genome single-nucleotide polymorphisms showed that the Haiti outbreak strain is genetically related to strains originating in India and Cameroon. However, because no identical genetic match was found among sequenced contemporary isolates, a definitive genetic origin for the outbreak in Haiti remains speculative. PMID:22099115

  2. Pre-earthquake non-epidemic Vibrio cholerae in Haiti.

    Science.gov (United States)

    Liu, Jie; Winstead-Derlega, Christopher; Houpt, Eric; Heidkamp, Rebecca; Pape, Jean; Dillingham, Rebecca

    2014-01-15

    To our knowledge, there was no record of Vibrio cholerae in Haiti until the 2010 post earthquake outbreak. This study describes the analysis of 301 stool samples from 117 infants in Port-au-Prince, Haiti, who participated in a pediatric nutrition study between July 2008 and October 2009. Nine samples were identified positive with both SYBR Green and Taqman-MGB probe based molecular assays targeting V. cholerae hlyA and toxR, respectively (Ct = 33-40), but none were O1 or O139. Our results from multiple molecular assays demonstrate the presence of non-O1/O139 V. cholerae DNA in stools collected from nine asymptomatic Haitian infants two years prior to the 2010 earthquake.

  3. Peptide nucleic acid fluorescence in-situ hybridization for identification of Vibrio spp. in aquatic products and environments.

    Science.gov (United States)

    Zhang, Xiaofeng; Li, Ke; Wu, Shan; Shuai, Jiangbing; Fang, Weihuan

    2015-08-03

    A peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) method was developed for specific detection of the Vibrio genus. In silico analysis by BLAST and ProbeCheck showed that the designed PNA probe targeting the 16S rRNAs was suitable for specific identification of Vibrio. Specificity and sensitivity of the probe Vib-16S-1 were experimentally verified by its reactivity against 18 strains of 9 Vibrio species and 14 non-Vibrio strains of 14 representative species. The PNA-FISH assay was able to identify 47 Vibrio positive samples from selectively enriched cultures of 510 samples of aquatic products and environments, comparable with the results obtained by biochemical identification and real-time PCR. We conclude that PNA-FISH can be an alternative method for rapid identification of Vibrio species in a broad spectrum of seafood or related samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Genetic diversity of culturable Vibrio in an Australian blue mussel Mytilus galloprovincialis hatchery.

    Science.gov (United States)

    Kwan, Tzu Nin; Bolch, Christopher J S

    2015-09-17

    Bacillary necrosis associated with Vibrio species is the common cause of larval and spat mortality during commercial production of Australian blue mussel Mytilus galloprovincialis. A total of 87 randomly selected Vibrio isolates from various stages of rearing in a commercial mussel hatchery were characterised using partial sequences of the ATP synthase alpha subunit gene (atpA). The sequenced isolates represented 40 unique atpA genotypes, overwhelmingly dominated (98%) by V. splendidus group genotypes, with 1 V. harveyi group genotype also detected. The V. splendidus group sequences formed 5 moderately supported clusters allied with V. splendidus/V. lentus, V. atlanticus, V. tasmaniensis, V. cyclitrophicus and V. toranzoniae. All water sources showed considerable atpA gene diversity among Vibrio isolates, with 30 to 60% of unique isolates recovered from each source. Over half (53%) of Vibrio atpA genotypes were detected only once, and only 7 genotypes were recovered from multiple sources. Comparisons of phylogenetic diversity using UniFrac analysis showed that the culturable Vibrio community from intake, header, broodstock and larval tanks were phylogenetically similar, while spat tank communities were different. Culturable Vibrio associated with spat tank seawater differed in being dominated by V. toranzoniae-affiliated genotypes. The high diversity of V. splendidus group genotypes detected in this study reinforces the dynamic nature of microbial communities associated with hatchery culture and complicates our efforts to elucidate the role of V. splendidus group bacteria in vibriosis.

  5. Vibrio bivalvicida sp. nov., a novel larval pathogen for bivalve molluscs reared in a hatchery.

    Science.gov (United States)

    Dubert, Javier; Romalde, Jesús L; Prado, Susana; Barja, Juan L

    2016-02-01

    Three isolates were obtained from cultures of carpet shell clam (Ruditapes decussatus) reared in a bivalve hatchery (Galicia, NW Spain) from different sources: healthy broodstock, moribund larvae and the seawater corresponding to the larval tank. All isolates were studied by a polyphasic approach, including a phylogenetic analysis based on concatenated sequences of the five housekeeping genes ftsZ, gyrB, pyrH, recA and rpoA. The analysis supported their inclusion in the Orientalis clade of the genus Vibrio, and they formed a tight group separated from the closest relatives: Vibrio tubiashii subsp. europaensis, Vibrio tubiashii subsp. tubiashii and Vibrio orientalis. The percentages of genomic resemblance, including average nucleotide identity, DNA-DNA hybridization and in silico genome-to-genome comparison, between the type strain and the closest relatives were below values for species delineation and confirmed the taxonomic position of the new species, which could be differentiated from the related taxa on the basis of several phenotypic and chemotaxonomic features, including FAME and MALDI-TOF-MS. The pathogenicity of the new species was demonstrated in larvae of R. decussatus, Ruditapes philippinarum, Ostrea edulis and Donax trunculus. The results demonstrated that the strains analyzed represented a novel species in the Orientalis clade of the genus Vibrio, for which the name Vibrio bivalvicida sp. nov. is proposed, with 605(T) (= CECT 8855(T)=CAIM 1904(T)) designated as the type strain. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Prevalensi Gen tdh dan trh Vibrio parahaemolyticus pada Udang Vaname Di Wilayah Indramayu, Jawa Barat

    Directory of Open Access Journals (Sweden)

    Yusma Yennie

    2015-06-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui prevalensi Vibrio parahaemolyticus patogenik pada udang vaname yang berasal dari tambak tradisional dan intensif berdasarkan keberadaan gen tdh dan trh. Isolasi dan konfirmasi Vibrio parahaemolyticus mengacu pada BAM (2004, yang dilanjutkan dengan konfirmasi gen tdh dan trh Vibrio parahaemolyticus  menggunakan metode PCR.  Hasil identifikasi menunjukkan bahwa  sebanyak 16/32(50% dan 6/32 (18,8% udang dari tambak tradisional dan intensif positif Vibrio parahaemolyticus. Berdasarkan gen tdh, ditemukan Vibrio parahaemolyticus patogenik pada udang tambak tradisional dan intensif berturut-turut adalah 81% (13/16 dan 50% (3/6. Sementara itu, jika didasarkan pada gen trh, Vibrio parahaemolyticus patogenik pada udang tambak tradisional dan intensif berturut-turut adalah 15/16 (93,8% dan 4/6 (66,7%. Secara keseluruhan prevalensi udang vaname yang positif gen tdh adalah sebesar 72,2% (16/22 gen trh sebesar 86,4% (19/22 dan yang memiliki kedua gen adalah sebanyak 63,6% (14/22.

  7. Rare Helicobacter pylori Virulence Genotypes in Bhutan.

    Science.gov (United States)

    Matsunari, Osamu; Miftahussurur, Muhammad; Shiota, Seiji; Suzuki, Rumiko; Vilaichone, Ratha-Korn; Uchida, Tomohisa; Ratanachu-ek, Thawee; Tshering, Lotay; Mahachai, Varocha; Yamaoka, Yoshio

    2016-03-02

    Both the prevalence of Helicobacter pylori infection and the incidence of gastric cancer are high in Bhutan. The high incidence of atrophic gastritis and gastric cancer suggest the phylogeographic origin of an infection with a more virulent strain of H. pylori. More than 90% of Bhutanese strains possessed the highly virulent East Asian-type CagA and all strains had the most virulent type of vacA (s1 type). More than half also had multiple repeats in East Asian-type CagA, which are rare in other countries and are reported characteristictly found in assciation with atrophic gastritis and gastric cancer consistent with Bhutanese strains having multiple H. pylori virulence factors associated with an increase in gastric cancer risk. Phylogeographic analyses showed that most Bhutanese strains belonged to the East Asian population type with some strains (17.5%) sharing East Asian and Amerindian components. Only 9.5% belonged to the European type consistant with H. pylori in Bhutan representing an intermediate evolutionary stage between H. pylori from European and East Asian countries.

  8. NEW VIRULENCE FACTORS OF STREPTOCOCCUS PNEUMONIAE

    NARCIS (Netherlands)

    Hermans, Peter Wilhelmus Maria; Bootsma, Jeanette Hester; Burghout, Pieter Jan; Kuipers, Oscar; Bijlsma, Johanna Jacoba Elisabeth; Kloosterman, Tomas Gerrit; Andersen, Christian O.

    2011-01-01

    The present invention provides proteins/genes, which are essential for survival, and consequently, for virulence of Streptococcus pneumoniae in vivo, and thus are ideal vaccine candidates for a vaccine preparation against pneumococcal infection. Further, also antibodies against said protein(s) are

  9. Salmonella virulence plasmid: pathogenesis and ecology.

    Science.gov (United States)

    Silva, Claudia; Puente, José Luis; Calva, Edmundo

    2017-06-22

    A current view on the role of the Salmonella virulence plasmid in the pathogenesis of animal and human hosts is discussed; including the possible relevance in secondary ecological niches. Various strategies towards further studies in this respect are proposed within the One Health Concept. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Efflux inhibitor suppresses Streptococcus mutans virulence properties.

    Science.gov (United States)

    Zeng, Huihui; Liu, Jia; Ling, Junqi

    2017-04-01

    It is well established that efflux pumps play important roles in bacterial pathogenicity and efflux inhibitors (EIs) have been proved to be effective in suppressing bacterial virulence properties. However, little is known regarding the EI of Streptococcus mutans, a well-known caries-inducing bacterium. In this study, we identified the EI of S. mutans through ethidium bromide efflux assay and investigated how EI affected S. mutans virulence regarding the cariogenicity and stress response. Results indicated that reserpine, the identified EI, suppressed acid tolerance, mutacin production and transformation efficiency of S. mutans, and modified biofilm architecture and extracellular polysaccharide distribution. Suppressed glycosyltransferase activity was also noted after reserpine exposure. The data from quantitative real-time-PCR demonstrated that reserpine significantly altered the expression profile of quorum-sensing and virulence-associated genes. These findings suggest that reserpine represents a promising adjunct anticariogenic agent in that it suppresses virulence properties of S. mutans. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Regulation of lux Genes in Vibrio fischeri: Control of Symbiosis-Related Gene Expression System in a Marine Bacterium

    Science.gov (United States)

    1989-11-04

    RR04106 411d019 11 TITLE (Include Security Classification) U. Regulation of lux Genes in Vibrio fischeri : Control of a Symbiosis-Related Gene Expression...communication - - 19 ABSTRACT (Continue on reverse if necessary and identify by block number) The lux genes of Vibrio fischeri encode the ability of this...Regulation of lux Genes in Vibrio fischeri : Control of a Symbiosis-related Gene Expression System in a Marine Bacterium START DATE: 15 August 1988

  12. Systemic Approach to Virulence Gene Network Analysis for Gaining New Insight into Cryptococcal Virulence

    Directory of Open Access Journals (Sweden)

    Antoni N Malachowski

    2016-10-01

    Full Text Available Cryptococcus neoformans is pathogenic yeast, responsible for highly lethal infections in compromised patients around the globe. C. neoformans typically initiates infections in mammalian lung tissue and subsequently disseminates to the central nervous system where it causes significant pathologies. Virulence genes of C. neoformans are being characterized at an increasing rate, however, we are far from a comprehensive understanding of their roles and genetic interactions. Some of these reported virulence genes are scattered throughout different databases, while others are not yet included. This study gathered and analyzed 150 reported virulence associated factors (VAFs of C. neoformans. Using the web resource STRING database, our study identified different interactions between the total VAFs and those involved specifically in lung and brain infections and identified a new strain specific virulence gene, sho1, involved in the mitogen-activated protein kinase signaling pathway. As predicted by our analysis, sho1 expression enhanced C. neoformans virulence in a mouse model of pulmonary infection, contributing to enhanced non-protective immune Th2 bias and progressively enhancing fungal growth in the infected lungs. Sequence analysis indicated 77.4% (116 of total studied VAFs are soluble proteins, and 22.7% (34 are transmembrane proteins. Motifs involved in regulation and signaling such as protein kinases and transcription factors are highly enriched in Cryptococcus VAFs. Altogether, this study represents a pioneering effort in analysis of the virulence composite network of C. neoformans using a systems biology approach.

  13. Sample collection of virulent and non-virulent B. anthracis and Y. pestis for bioforensics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong-geller, Elizabeth [Los Alamos National Laboratory; Valdez, Yolanda E [Los Alamos National Laboratory; Shou, Yulin [Los Alamos National Laboratory; Yoshida, Thomas M [Los Alamos National Laboratory; Marrone, Babetta L [Los Alamos National Laboratory; Dunbar, John [Los Alamos National Laboratory

    2009-01-01

    Validated sample collection methods are needed for recovery of microbial evidence in the event of accidental or intentional release of biological agents into the environment. To address this need, we evaluated the sample recovery efficiencies of two collection methods -- swabs and wipes -- for both non-virulent and virulent strains of B. anthracis and Y. pestis from four types of non-porous surfaces: two hydrophilic surfaces, stainless steel and glass, and two hydrophobic surfaces, vinyl and plastic. Sample recovery was quantified using Real-time qPCR to assay for intact DNA signatures. We found no consistent difference in collection efficiency between swabs or wipes. Furthermore, collection efficiency was more surface-dependent for virulent strains than non-virulent strains. For the two non-virulent strains, B. anthracis Sterne and Y. pestis A1122, collection efficiency was approximately 100% and 1 %, respectively, from all four surfaces. In contrast, recovery of B. anthracis Ames spores and Y. pestis C092 from vinyl and plastic was generally lower compared to collection from glass or stainless steel, suggesting that surface hydrophobicity may playa role in the strength of pathogen adhesion. The surface-dependent collection efficiencies observed with the virulent strains may arise from strain-specific expression of capsular material or other cell surface receptors that alter cell adhesion to specific surfaces. These findings contribute to validation of standard bioforensics procedures and emphasize the importance of specific strain and surface interactions in pathogen detection.

  14. Systemic Approach to Virulence Gene Network Analysis for Gaining New Insight into Cryptococcal Virulence.

    Science.gov (United States)

    Malachowski, Antoni N; Yosri, Mohamed; Park, Goun; Bahn, Yong-Sun; He, Yongqun; Olszewski, Michal A

    2016-01-01

    Cryptococcus neoformans is pathogenic yeast, responsible for highly lethal infections in compromised patients around the globe. C. neoformans typically initiates infections in mammalian lung tissue and subsequently disseminates to the central nervous system where it causes significant pathologies. Virulence genes of C. neoformans are being characterized at an increasing rate, however, we are far from a comprehensive understanding of their roles and genetic interactions. Some of these reported virulence genes are scattered throughout different databases, while others are not yet included. This study gathered and analyzed 150 reported virulence associated factors (VAFs) of C. neoformans. Using the web resource STRING database, our study identified different interactions between the total VAFs and those involved specifically in lung and brain infections and identified a new strain specific virulence gene, SHO1, involved in the mitogen-activated protein kinase signaling pathway. As predicted by our analysis, SHO1 expression enhanced C. neoformans virulence in a mouse model of pulmonary infection, contributing to enhanced non-protective immune Th2 bias and progressively enhancing fungal growth in the infected lungs. Sequence analysis indicated 77.4% (116) of total studied VAFs are soluble proteins, and 22.7% (34) are transmembrane proteins. Motifs involved in regulation and signaling such as protein kinases and transcription factors are highly enriched in Cryptococcus VAFs. Altogether, this study represents a pioneering effort in analysis of the virulence composite network of C. neoformans using a systems biology approach.

  15. Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

    Directory of Open Access Journals (Sweden)

    S. González Fraga

    2009-03-01

    Full Text Available La infección por Vibrio cholerae, el agente causal del cólera, se trasmite al hombre por ingestión de agua y alimentos contaminados. Aunque son los serogrupos O1 y O139 los que habitualmente se asocian al cólera epidémico, los aislamientos de otros serogrupos también son causales de gastroenteritis e infecciones extra-intestinales. Durante el período 2003-2005, se investigó la presencia de V. cholerae en la materia fecal de niños con diarrea atendidos en el Hospital del Niño Jesús, Tucumán. Se recuperaron 34 aislamientos de V. cholerae no-O1, no-O139. Se determinaron sus perfiles de virulencia por PCR, la sensibilidad a los antimicrobianos y la diversidad genética por electroforesis en campo pulsado. Se obtuvieron ocho perfiles de virulencia, aunque ningún aislamiento fue positivo para la toxina colérica ni para la toxina termoestable. Cuatro aislamientos fueron positivos para el sistema de secreción de tipo tres. El 17,6% de los aislamientos fueron resistentes o de sensibilidad intermedia a ampicilina y el 5,9% fueron resistentes a trimetoprima-sulfametoxazol. Los aislamientos resultaron muy diversos: se hallaron 27 patrones distintos en 29 aislamientos tipificables por electroforesis en campo pulsado. A pesar de su baja incidencia, V. cholerae continúa siendo un agente causal de diarrea en niños, los que se ven afectados por una amplia variedad de cepas circulantes.Vibrio cholerae, etiologic agent of cholera, is transmitted to humans by ingestion of contaminated food or water. Even though serogroups O1 and O139 are the ones usually associated to epidemic cholera, isolates from other serogroups also cause gastroenteritis and extraintestinal infections. During the period 2003-2005, presence of V. cholerae in stools was investigated in children with diarrhea that seaked assistance at the Niño Jesús Hospital in Tucumán. Thirty four isolates of V. cholerae non-O1, non-O139 were recovered. We characterized the isolates studying

  16. Molecular characterisation of Vibrio cholerae O1 strains carrying an SXT/R391-like element from cholera outbreaks in Kenya: 1994-2007

    Directory of Open Access Journals (Sweden)

    Goddeeris Bruno M

    2009-12-01

    Full Text Available Abstract Background Over the last decade, cholera outbreaks in parts of Kenya have become common. Although a number of recent studies describe the epidemiology of cholera in Kenya, there is paucity of information concerning the diversity and occurrence of mobile genetic elements in Vibrio cholerae strains implicated in these outbreaks. A total of 65 Vibrio cholerae O1 El Tor serotype Inaba isolated between 1994 and 2007 from various outbreaks in Kenya were investigated for mobile genetic elements including integrons, transposons, the integrating conjugative elements (ICEs, conjugative plasmids and for their genotypic relatedness. Results All the strains were haemolytic on 5% sheep blood and positive for the Vibrio cholerae El Tor-specific haemolysin toxin gene (hylA by PCR. They all contained strB, sulII, floR and the dfrA1 genes encoding resistance to streptomycin, sulfamethoxazole, chloramphenicol and trimethoprim respectively. These genes, together with an ICE belonging to the SXT/R391 family were transferable to the rifampicin-resistant E. coli C600 en bloc. All the strains were negative for integron class 1, 2 and 3 and for transposase gene of transposon Tn7 but were positive for integron class 4 and the trpM gene of transposon Tn21. No plasmids were isolated from any of the 65 strains. All the strains were also positive for all V. cholera El Tor pathogenic genes except the NAG- specific heat-stable toxin (st gene. None of the strains were positive for virulence genes associated with the V. cholerae classical biotype. All the strains were positive for El Tor-specific CTXphi bacteriophage rstrR repressor gene (CTXETΦ but negative for the Classical, Calcutta, and the Environmental repressor types. Pulse Field Gel Electrophoresis (PFGE showed that regardless of the year of isolation, all the strains bearing the SXT element were clonally related. Conclusions This study demonstrates that the V. cholerae O1 strains carrying an SXT/R391-like

  17. Coordination of the arc regulatory system and pheromone-mediated positive feedback in controlling the Vibrio fischeri lux operon

    National Research Council Canada - National Science Library

    Septer, Alecia N; Stabb, Eric V

    2012-01-01

    .... We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium...

  18. Relative contributions of Vibrio polysaccharide and quorum sensing to the resistance of Vibrio cholerae to predation by heterotrophic protists.

    Directory of Open Access Journals (Sweden)

    Shuyang Sun

    Full Text Available Protozoan grazing is a major mortality factor faced by bacteria in the environment. Vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. Previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of Vibrio polysaccharide (VPS. In addition to negatively controlling vps genes, the global quorum sensing (QS regulator, HapR, plays a role in grazing resistance as the ΔhapR strain is efficiently consumed while the wild type (WT is not. Here, the relative and combined contributions of VPS and QS to grazing resistance were investigated by exposing VPS and HapR mutants and double mutants in VPS and HapR encoding genes at different phases of biofilm development to amoeboid and flagellate grazers. Data show that the WT biofilms were grazing resistant, the VPS mutants were less resistant than the WT strain, but more resistant than the QS mutant strain, and that QS contributes to grazing resistance mainly in mature biofilms. In addition, grazing effects on biofilms of mixed WT and QS mutant strains were investigated. The competitive fitness of each strain in mixed biofilms was determined by CFU and microscopy. Data show that protozoa selectively grazed the QS mutant in mixed biofilms, resulting in changes in the composition of the mixed community. A small proportion of QS mutant cells which comprised 4% of the mixed biofilm biovolume were embedded in grazing resistant WT microcolonies and shielded from predation, indicating the existence of associational protection in mixed biofilms.

  19. Survey on antimicrobial resistance patterns in Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 in Germany reveals carbapenemase-producing Vibrio cholerae in coastal waters

    Directory of Open Access Journals (Sweden)

    Nadja eBier

    2015-10-01

    Full Text Available An increase in the occurrence of potentially pathogenic Vibrio species is expected for waters in Northern Europe as a consequence of global warming. In this context, a higher incidence of Vibrio infections is predicted for the future and forecasts suggest that people visiting and living at the Baltic Sea are at particular risk.This study aimed to investigate antimicrobial resistance patterns among Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 isolates that could pose a public health risk. Antimicrobial susceptibility of 141 V. vulnificus and 184 V. cholerae non-O1/non-O139 strains isolated from German coastal waters (Baltic Sea and North Sea as well as from patients and retail seafood was assessed by broth microdilution and disk diffusion. Both species were susceptible to most of the agents tested (12 subclasses and no multidrug-resistance was observed. Among V. vulnificus isolates, non-susceptibility was exclusively found towards aminoglycosides. In case of V. cholerae, a noticeable proportion of strains was non-susceptible to aminopenicillins and aminoglycosides. In addition, resistance towards carbapenems, quinolones, and folate pathway inhibitors was sporadically observed. Biochemical testing indicated the production of carbapenemases with unusual substrate specificity in four environmental V. cholerae strains. Most antimicrobial agents recommended for treatment of V. vulnificus and V. cholerae non-O1/non-O139 infections were found to be effective in vitro. However, the occurrence of putative carbapenemase producing V. cholerae in German coastal waters is of concern and highlights the need for systematic monitoring of antimicrobial susceptibility in potentially pathogenic Vibrio spp. in Europe.

  20. Genome sequencing reveals unique mutations in characteristic metabolic pathways and the transfer of virulence genes between V. mimicus and V. cholerae.

    Directory of Open Access Journals (Sweden)

    Duochun Wang

    Full Text Available Vibrio mimicus, the species most similar to V. cholerae, is a microbe present in the natural environmental and sometimes causes diarrhea and internal infections in humans. It shows similar phenotypes to V. cholerae but differs in some biochemical characteristics. The molecular mechanisms underlying the differences in biochemical metabolism between V. mimicus and V. cholerae are currently unclear. Several V. mimicus isolates have been found that carry cholera toxin genes (ctxAB and cause cholera-like diarrhea in humans. Here, the genome of the V. mimicus isolate SX-4, which carries an intact CTX element, was sequenced and annotated. Analysis of its genome, together with those of other Vibrio species, revealed extensive differences within the Vibrionaceae. Common mutations in gene clusters involved in three biochemical metabolism pathways that are used for discrimination between V. mimicus and V. cholerae were found in V. mimicus strains. We also constructed detailed genomic structures and evolution maps for the general types of genomic drift associated with pathogenic characters in polysaccharides, CTX elements and toxin co-regulated pilus (TCP gene clusters. Overall, the whole-genome sequencing of the V. mimicus strain carrying the cholera toxin gene provides detailed information for understanding genomic differences among Vibrio spp. V. mimicus has a large number of diverse gene and nucleotide differences from its nearest neighbor, V. cholerae. The observed mutations in the characteristic metabolism pathways may indicate different adaptations to different niches for these species and may be caused by ancient events in evolution before the divergence of V. cholerae and V. mimicus. Horizontal transfers of virulence-related genes from an uncommon clone of V. cholerae, rather than the seventh pandemic strains, have generated the pathogenic V. mimicus strain carrying cholera toxin genes.

  1. Epidemiological evidence of lesser role of thermostable direct hemolysin (TDH)-related hemolysin (TRH) than TDH on Vibrio parahaemolyticus pathogenicity.

    Science.gov (United States)

    Saito, Shioko; Iwade, Yoshito; Tokuoka, Eisuke; Nishio, Tomohiro; Otomo, Yoshimitsu; Araki, Emiko; Konuma, Hirotaka; Nakagawa, Hiroshi; Tanaka, Hiroyuki; Sugiyama, Kanji; Hasegawa, Akio; Sugita-Konishi, Yoshiko; Hara-Kudo, Yukiko

    2015-02-01

    Vibrio parahaemolyticus carrying the tdh gene, encoding the thermostable direct hemolysin (TDH), or the trh gene, encoding the TDH-related hemolysin (TRH), are both considered virulent strains. There are, however, disproportionally fewer reports of infections caused by seafood contaminated with trh-positive strains than by seafood contaminated with tdh-positive strains. Bivalves such as clams and oysters are the major seafood varieties associated with the infections. In this study, the prevalence of strains possessing the tdh and trh genes was investigated in Japan in 74 samples collected in 2007-2008 and in 177 samples collected in 2010 of domestic bivalves, bloody clams, hen clams, short-neck clams, and rock oysters. The tdh-positive and trh-negative, tdh-negative and trh-positive, and tdh-positive and trh-positive samples represented 5.4%, 12.2%, and 4.1% of all samples collected in 2007-2008, and 5.1%, 18.6%, and 5.6% of all samples collected in 2010, respectively. As determined by polymerase chain reaction, the prevalence of tdh negative and trh positive in all samples was two to four times higher than that of tdh positive and trh negative. In the samples collected in 2010, the tdh-negative and trh-positive V. parahaemolyticus (20 samples) was more often isolated than tdh-positive and trh-negative V. parahaemolyticus (7 samples). The most common serotype of tdh-positive isolates (22 of 24 strains) was pandemic O3:K6. The trh-positive isolates (61 strains) were various serotypes including OUT:KUT. In 330 V. parahaemolyticus outbreaks and sporadic infections in Japan, most outbreaks and sporadic infections were caused by tdh-positive and trh-negative strains (89.4%). The frequencies of infections caused by tdh-negative and trh-positive, and both tdh- and trh-positive strains were 1.2% and 3.0%, respectively. This finding suggests that the virulence of trh might be less than that of tdh, although trh-positive V. parahaemolyticus frequently contaminated bivalves.

  2. Crystal structure of an integron gene cassette-associated protein from Vibrio cholerae identifies a cationic drug-binding module.

    Directory of Open Access Journals (Sweden)

    Chandrika N Deshpande

    2011-03-01

    Full Text Available The direct isolation of integron gene cassettes from cultivated and environmental microbial sources allows an assessment of the impact of the integron/gene cassette system on the emergence of new phenotypes, such as drug resistance or virulence. A structural approach is being exploited to investigate the modularity and function of novel integron gene cassettes.We report the 1.8 Å crystal structure of Cass2, an integron-associated protein derived from an environmental V. cholerae. The structure defines a monomeric beta-barrel protein with a fold related to the effector-binding portion of AraC/XylS transcription activators. The closest homologs of Cass2 are multi-drug binding proteins, such as BmrR. Consistent with this, a binding pocket made up of hydrophobic residues and a single glutamate side chain is evident in Cass2, occupied in the crystal form by polyethylene glycol. Fluorescence assays demonstrate that Cass2 is capable of binding cationic drug compounds with submicromolar affinity. The Cass2 module possesses a protein interaction surface proximal to its drug-binding cavity with features homologous to those seen in multi-domain transcriptional regulators.Genetic analysis identifies Cass2 to be representative of a larger family of independent effector-binding proteins associated with lateral gene transfer within Vibrio and closely-related species. We propose that the Cass2 family not only has capacity to form functional transcription regulator complexes, but represents possible evolutionary precursors to multi-domain regulators associated with cationic drug compounds.

  3. Nitric oxide as an antimicrobial molecule against Vibrio harveyi infection in the hepatopancreas of Pacific white shrimp, Litopenaeus vannamei.

    Science.gov (United States)

    Chen, Ting; Wong, Nai-Kei; Jiang, Xiao; Luo, Xing; Zhang, Lvping; Yang, Dan; Ren, Chunhua; Hu, Chaoqun

    2015-01-01

    Nitric oxide (NO) is a key effector molecule produced in the innate immune systems of many species for antimicrobial defense. However, how NO production is regulated during bacterial infection in invertebrates, especially crustaceans, remains poorly understood. Vibrio harveyi, a Gram-negative marine pathogen, is among the most prevalent and serious threats to the world's shrimp culture industry. Its virulence typically manifests itself through shrimp hepatopancreas destruction. In the current study, we found that NO generated by an in vitro donor system (NOC-18) could rapidly and effectively kill V. harveyi. In addition, injection of heat-killed V. harveyi increased the concentration of NO/nitrite and the mRNA expression of nitric oxide synthase (NOS) in the hepatopancreas of Pacific white shrimp (Litopenaeus vannamei), the commercially most significant shrimp species. Live V. harveyi challenge also induced NO/nitrite production and NOS gene expression in primary L. vannamei hepatopancreatic cells in a time- and dose-dependent manner. Co-incubation of l-NAME, an inhibitor selective for mammalian constitutive NOSs, dose-dependently blocked V. harveyi-induced NO/nitrite production, without affecting V. harveyi-induced NOS mRNA expression. Furthermore, l-NAME treatment significantly increased the survival rate of infecting V. harveyi in cultured primary hepatopancreatic cells of L. vannamei. As a whole, we have demonstrated that endogenous NO produced by L. vannamei hepatopancreatic cells occurs in enzymatically regulated manners and is sufficient to act as a bactericidal molecule for V. harveyi clearance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Multidrug-Resistant Vibrio cholerae O1 was Responsible for a Cholera Outbreak in 2013 in Bagalkot, North Karnataka.

    Science.gov (United States)

    Bhattacharya, Debdutta; Dey, Shuchismita; Roy, Subarna; Parande, Mahantesh V; Telsang, M; Seema, M H; Parande, Aisha V; Mantur, Basappa G

    2015-01-01

    Cholera is a major cause of illness in the developing world. During the monsoon season, small sporadic clusters of cholera cases are reported on an annual basis in Karnataka, India. During the monsoons of 2013, there was a cholera outbreak in Badami, a remote area of Bagalkot district in Karnataka. The multi-drug-resistant Vibrio cholerae O1 serotype Ogawa was found to be responsible for this outbreak. On 5 August 2013, a 30-year-old woman presented with severe dehydration and watery diarrhea at the Aganwadi Health Centre in Badami. A total of 49 suspected cholera cases were reported, with an attack rate of 3.5%. The V. cholerae isolates exhibited resistance to a wide range of drugs, including ampicillin, co-trimoxazole, nitrofurantoin, carbenicillin, and third generation cephalosporins, and showed reduced susceptibility to third generation fluoroquinolones. All of the cephalosporin-resistant V. cholerae strains produced extended-spectrum beta-lactamase. All V. cholerae O1 isolates harbored virulent genes (ctxA, ctxB, tcpA El Tor, Tox S, VPI, ToxT, ToxR, ToxRS, ace, zot, and tcpP) and were found to be genetically similar as determined by randomly amplified polymorphic DNA fingerprinting assay. To the best of our knowledge, this is the first report of a cholera outbreak in the district of Bagalkot. The resistance of V. cholerae to commonly used antimicrobial drugs is becoming a major public health concern in the region as clinicians are left with a limited choice of antibiotics for the treatment of cholera.

  5. Detection of Total and Pathogenic Vibrio parahaemolyticus in Shellfish Growing along the South Yellow Sea and the East China Sea.

    Science.gov (United States)

    Han, Feng; Gu, Run-Run; Shen, Xiao-Sheng; Chen, Yuan-Ge; Tian, Liang-Liang; Zhou, Wei-Feng; Cai, You-Qiong

    2017-10-17

    This study was conducted to monitor the densities of total and pathogenic Vibrio parahaemolyticus in 300 samples of nine shellfish species harvested from the coasts of the South Yellow Sea and the East China Sea (N 23° to 34°, E 116° to 124°), People's Republic of China, between May and October 2015. Total V. parahaemolyticus densities were measured, and V. parahaemolyticus isolates were biochemically identified with probes for the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh). We found that 202 of the 300 samples were positive for V. parahaemolyticus from all the sites: 58 of the 100 samples from the Fujian province, 71 of the 100 samples from the Zhejiang province, and 73 of the 100 samples from the Jiangsu province. In most (170) of the 300 samples, V. parahaemolyticus densities were 0.3 to 10 most probable number (MPN)/g; five lots exceeded 110 MPN/g, and two lots were estimated at 110 MPN/g. Among the 202 V. parahaemolyticus strains, only one was trh positive. Densities of V. parahaemolyticus in these shellfish were temperature dependent, with highest densities in June and July. Among the nine mollusk species, V. parahaemolyticus was most abundant in the agemaki clam (Sinonovacula constricta). The highest and lowest V. parahaemolyticus prevalences were found in oriental cyclina (Cyclina sinensis, 93.8%) and mussels (Mytilus edulis, 28.1%), respectively. Overall, although V. parahaemolyticus is widely distributed in marine environments, the density of V. parahaemolyticus was low and the prevalence of the main virulence factor was very low in shellfish along the coasts of the South Yellow Sea and East China Sea, which is important from a public health perspective. Data presented here will be useful for correlational research and can be utilized for developing risk management plans that establish food safety guidelines for V. parahaemolyticus in Chinese shellfish.

  6. Molecular and Conventional Analysis of Acute Diarrheal Isolates Identifies Epidemiological Trends, Antibiotic Resistance and Virulence Profiles of Common Enteropathogens in Shanghai

    Directory of Open Access Journals (Sweden)

    Feng Yang

    2018-02-01

    Full Text Available Objective: To investigate prevalence of acute diarrhea in Shanghai and analyze virulence associated-genes and antibiotic resistance of major enteropathogens using combination of conventional and molecular epidemiology methods.Method: The 412 stool specimens were obtained by systematic sampling from diarrhea patients throughout entire year 2016. Bacterial and viral pathogens were identified and bacterial isolates were cultured and screened for antibiotic resistance profiles. Two most prevalent bacteria, Vibrio parahaemolyticus and Salmonella were further typed by multi-locus sequence typing (MLST and analyzed for presence of virulence-associated genes. The association between virulence genes, resistance phenotypes and genetic diversities was analyzed.Results: Among stool specimens testing positive for pathogens (23.1%, 59 bacterial and 36 viral pathogens were identified. V. parahaemolyticus (27/412, 6.6%, Salmonella (23/412, 5.6% and norovirus GII (21/412, 5.1% were three most-commonly found. Most bacterial isolates exhibited high levels of antibiotic resistance with high percentage of MDR. The drug resistance rates of V. parahaemolyticus and Salmonella isolates to cephalosporins were high, such as 100.0 and 34.8% to CFX, 55.6 and 43.4% to CTX, 92.6 and 95.7% to CXM, respectively. The most common resistance combination of V. parahaemolyticus and Salmonella was cephalosporins and quinolone. The dominant sequence types (STs of V. parahaemolyticus and Salmonella were ST3 (70.4% and ST11 (43.5%, respectively. The detection rates of virulence genes in V. parahaemolyticus were tlh (100% and tdh (92.6%, without trh and ureR. Most of the Salmonella isolates were positive for the Salmonella pathogenicity islands (SPIs genes (87–100%, and some for Salmonella plasmid virulence (SPV genes (34.8% for spvA and spvB, 43.5% for spvC. In addition, just like the drug resistance, virulence genes exhibited wide-spread distribution among the different STs albeit

  7. Relationships between environmental factors and pathogenic Vibrios in the Northern Gulf of Mexico.

    Science.gov (United States)

    Johnson, C N; Flowers, A R; Noriea, N F; Zimmerman, A M; Bowers, J C; DePaola, A; Grimes, D J

    2010-11-01

    Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

  8. Vibrio sp. DSM 14379 pigment production--a competitive advantage in the environment?

    Science.gov (United States)

    Starič, Nejc; Danevčič, Tjaša; Stopar, David

    2010-10-01

    The ability to produce several antibacterial agents greatly increases the chance of producer's survival. In this study, red-pigmented Vibrio sp. DSM 14379 and Bacillus sp., both isolated from the same sampling volume from estuarine waters of the Northern Adriatic Sea, were grown in a co-culture. The antibacterial activity of the red pigment extract was tested on Bacillus sp. in microtiter plates. The MIC(50) for Bacillus sp. was estimated to be around 10⁻⁵ mg/L. The extract prepared form the nonpigmented mutant of Vibrio sp. had no antibacterial effect. The pigment production of Vibrio sp. was studied under different physicochemical conditions. There was no pigment production at high or low temperatures, high or low salt concentrations in peptone yeast extract (PYE) medium, low glucose concentration in mineral growth medium or high glucose concentration in PYE medium. This indicates that the red pigment production is a luxurious good that Vibrio sp. makes only under favorable conditions. The Malthusian fitness of Bacillus sp. in a co-culture with Vibrio sp. under optimal environmental conditions dropped from 4.0 to -7.6, which corresponds to three orders of magnitude decrease in the number of CFU relative to the monoculture. The nonpigmented mutant of Vibrio sp. in a co-culture with Bacillus sp. had a significant antibacterial activity. This result shows that studying antibacterial properties in isolation (i.e. pigment extract only) may not reveal full antibacterial potential of the bacterial strain. The red pigment is a redundant antibacterial agent of Vibrio sp.

  9. Immune responses of phenoloxidase and superoxide dismutase in the manila clam Venerupis philippinarum challenged with Vibrio tapetis--part II: combined effect of temperature and two V. tapetis strains.

    Science.gov (United States)

    Richard, Gaëlle; Le Bris, Cédric; Guérard, Fabienne; Lambert, Christophe; Paillard, Christine

    2015-05-01

    Manila clams, Venerupis philippinarum (Adams and Reeve, 1850), were experimentally infected with two different bacterial strains and challenged with two different temperatures. Bacterial strains used in this study were Vibrio tapetis strain CECT4600(T), the causative agent of Brown Ring Disease (BRD) and V. tapetis strain LP2, supposed less virulent to V. philippinarum. V. tapetis is considered to proliferate at low temperatures, i.e. under 21 °C. In a global warming context we could hypothesize a decrease of mass mortalities caused by V. tapetis but these thermal changes could also directly impact the immune system of the host V. philippinarum. Thus, the aim of this study was to investigate the effects of the extrapallial injection with V. tapetis combined with temperature challenge on two enzymes activities in V. philippinarum. More precisely, after infection, phenoloxidase (PO) and superoxide dismutase (SOD), two major enzymes involved in immune response, were studied for 30 days in two compartments: the mantle and the hemolymph. Conchyolin Deposit Stages (CDS) and Shell Repair Stages (SRS) were also determined 30 days post-injection as a proxy of the virulence of the tested strains. In this study, we highlighted that host-pathogen interaction in a varying environment affects the enzymatic response of the host. The coupled effect of V. tapetis injection and temperature challenge was detected 30 days post injection and resulted in virulence differences. These findings were supported by CDS and SRS determination in clams and lead to the conclusion that clam's immunity could be enhanced at 22 °C while V. tapetis virulence is lowered at this temperature. Another result of our study was the increase of PO and SOD basal activities as clams are exposed to warmer temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effectiveness of icing as a postharvest treatment for control of Vibrio vulnificus and Vibrio parahaemolyticus in the eastern oyster (Crassostrea virginica).

    Science.gov (United States)

    Melody, Kevin; Senevirathne, Reshani; Janes, Marlene; Jaykus, Lee Ann; Supan, John

    2008-07-01

    The focus of this research was to investigate the efficacy of icing as a postharvest treatment for reduction of the levels of Vibrio vulnificus and Vibrio parahaemolyticus in commercial quantities of shellstock oysters. The experiments were conducted in June and August of 2006 and consisted of the following treatments: (i) on-board icing immediately after harvest; (ii) dockside icing approximately 1 to 2 h prior to shipment; and (iii) no icing (control). Changes in the levels of pathogenic Vibrio spp. during wholesale and retail handling for 2 weeks postharvest were also monitored. On-board icing achieved temperature reductions in all sacks in accordance with the National Shellfish Sanitation Program standard, but dockside icing did not meet this standard. Based on one-way analysis of variance, the only statistically significant relationship between Vibrio levels and treatment occurred for samples harvested in August; in this case, the levels of V. vulnificus in the noniced oysters were significantly higher (P iced on-board. When analyzing counts over the 14-day storage period, using factorial analysis, there were statistically significant differences in V. vulnificus and V. parahaemolyticus levels by sample date and/or treatment (P iced) oysters had significantly higher gaping (approximately 20%) after 1 week in cold storage than did noniced oysters (approximately 10%) and gaping increased significantly by day 14 of commercial storage. On-board and dockside icing did not predictably reduce the levels of V. vulnificus or V. parahaemolyticus in oysters, and icing negatively impacted oyster survival during subsequent cold storage.

  11. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  12. Riboregulators: Fine-Tuning Virulence in Shigella.

    Science.gov (United States)

    Fris, Megan E; Murphy, Erin R

    2016-01-01

    Within the past several years, RNA-mediated regulation (ribo-regulation) has become increasingly recognized for its importance in controlling critical bacterial processes. Regulatory RNA molecules, or riboregulators, are perpetually responsive to changes within the micro-environment of a bacterium. Notably, several characterized riboregulators control virulence in pathogenic bacteria, as is the case for each riboregulator characterized to date in Shigella. The timing of virulence gene expression and the ability of the pathogen to adapt to rapidly changing environmental conditions is critical to the establishment and progression of infection by Shigella species; ribo-regulators mediate each of these important processes. This mini review will present the current state of knowledge regarding RNA-mediated regulation in Shigella by detailing the characterization and function of each identified riboregulator in these pathogens.

  13. Helicobacter pylori virulence factors in gastric carcinogenesis

    OpenAIRE

    Wen, Sicheng; Moss, Steven F.

    2008-01-01

    Helicobacter pylori infection is the most important risk factor in the development of non-cardia gastric adenocarcinoma; host genetic variability and dietary co-factors also modulate risk. Because most H. pylori infections do not cause cancer, H. pylori heterogeneity has been investigated to identify possible virulence factors. The strongest candidates are genes within the cag (cytotoxin associated antigen) pathogenicity island, including the gene encoding the CagA protein, as well as polymor...

  14. Vibrio cholerae Colonization of Soft-Shelled Turtles.

    Science.gov (United States)

    Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

    2017-07-15

    Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae-contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N-acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms.IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

  15. An outbreak of Vibrio cholerae in Vikas Nagar, Chandigarh, India

    Directory of Open Access Journals (Sweden)

    Sonia Puri

    2014-01-01

    Full Text Available Background : On 1 July 2012, a large number of cases of acute diarrheal episodes were reported in Vikas Nagar, Chandigarh. A rapid response team was sent to investigate this outbreak on 3 July 2012. Aim : To determine the reasons for the outbreak and to focus on the identification of a gap in the management of the epidemic by applying remedial measures in the Vibrio cholera outbreak in the Vikas Nagar area of Chandigarh district. Materials and Methods : A house-to-house survey of 2765 houses was performed with 20 teams of Auxillary Nurse Midwife ANM/Anganwadi workers. Information regarding age, sex, place of residence, occupation, date of onset and treatment history and laboratory finding were collected. Environmental investigation and laboratory investigation of the stool samples were also performed. As the study was conducted during an emergency response to the outbreak, and was designed to provide information to orient the public health response, ethical approval was not required. Remedial measures were implemented. Results : A total of 1875 patients reported to the various health facilities of the Vikas Nagar area with complaints of increased frequency of loose watery diarrhea and a few had vomiting episodes during the time period of 1 - 14 July 2012. Four deaths were reported. Three hundred eighteen (318 cases were found in the house-to-house survey of 2765 houses of the area. Twenty-six percent of the cases were in the age group of 1800 MPN/100 mL was reported from 10 water samples. Investigations revealed that the epidemic was waterborne. Leakages in the pipes were found at many places leading to mixing of water with drainage, and water samples collected from the houses of the cases were found to be positive for Vibrio cholerae. Conclusion : Among the identified gaps, delays in the initiation of the investigation of the epidemic and pipe leakages were the most important. In India, waterborne epidemics are usual occurrences during the year

  16. Infection Vibrio sp. Bacteria on Kappaphycus Seaweed Varieties Brown and Green

    Science.gov (United States)

    Irmawati, Yuni; Sudirjo, Fien

    2017-10-01

    Disease in seaweed or ice-ice, until today is still a major problem in the cultivation of seaweed. Changes in extreme environmental conditions is a trigger factor of ice-ice, which can result in seaweed susceptible to infection with pathogenic microorganisms, such as bacteria Vibrio sp. This research aims to determine the bacteria Vibrio sp. infection in seaweed Kappaphycus varieties of brown and green. Vibrio sp. bacteria isolated in the infected seaweed thallus ice-ice, grown on TCBS media, purification, gram staining and biochemical tests. Vibrio sp. infected to seaweed Kappaphycus brown and green varieties in containers controlled by different density, 105 CFU/ml, 106 CFU/ml and 107CFU/ml. Observations were made to change clinical effect in thallus seaweed for 14 days of observation. The results obtained show that the levels of infection bacteria Vibrio sp. higher in seaweed Kappaphycus green varieties both in density 105 CFU/ml, 106 CFU/ml and 107CFU/ml, when compared with varieties brown.

  17. Isolation of Vibrio parahaemolyticus from fecal specimens on mannitol salt agar.

    Science.gov (United States)

    Carruthers, M M; Kabat, W J

    1976-08-01

    Unless laboratories use an inhibitory medium, Vibrio parahaemolyticus will be unrecognizable in fecal specimens. The use of a medium exclusively for vibrio isolation, such as thiosulfate-citrate-bile salts-sucrose agar (TCBS), however, may not be considered economically justified in the United States. The isolation and recognition of V. parahaemolyticus is reported on mannitol salt agar (MS), a medium which is used for fecal specimens here. Eight Kanagawa-positive and two of three Kanagawa-negative strains of V. parahaemolyticus grew as well on MS as on TCBS and better than on a representative enteric medium, Hektoen enteric agar (HE). Twenty-two fecal specimens from 16 noninfected individuals were inoculated with known quantities of V. parahaemolyticus, and recovery of these vibrios was assessed on TCBS, MS, and HE. Recovery of vibrios from MS and TCBS was similar when inoculum size was 10(3) colony-forming units/ml or greater. Recovery of vibrios from mixed culture was distinctly lower on HE. The colonial morphology of V. parahaemolyticus and several other bacteria on MS is illustrated.

  18. Essential oils of Nigella sativa protects Artemia from the pathogenic effect of Vibrio parahaemolyticus Dahv2.

    Science.gov (United States)

    Manju, Sivalingam; Malaikozhundan, Balasubramanian; Withyachumnarnkul, Boonsirm; Vaseeharan, Baskaralingam

    2016-05-01

    The anti-Vibrio activity of essential oils (EOs) of nine medicinal plants was tested against 28 Vibrio spp. isolated from diseased Fenneropenaeus indicus. EO of Nigella sativa exhibited anti-Vibrio activity against all Vibrio spp. and greater inhibition was noted for the isolate V2 which was identified as Vibrio parahaemolyticus Dahv2. Further, EO of N. sativa effectively inhibited V. parahaemolyticus Dahv2 with an inhibition zone of 23.9mm at 101.2μgml(-1). Moreover, EO of N. sativa revealed anti-biofilm activity at 101.2μgml(-1) against V. parahaemolyticus Dahv2 and inhibited the growth of V. parahaemolyticus Dahv2 at 100μgml(-1).In vivo experimental infection studies showed that the survival of Artemia spp. infected with V. parahaemolyticus Dahv2 at 1×10(3)cfuml(-1) was only 40%. However, the survival of Artemia spp. was significantly increased after challenge with 100μgml(-1) of EO of N. sativa. EO of N. sativa showed higher anti-oxidant potential and total phenol content than other EOs tested. The anti-oxidant activity of EO of N. sativa was highly correlated to their total phenolic contents (r=0.836, PArtemia spp. after experimental infection of V. parahaemolyticus Dahv2. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios.

    Science.gov (United States)

    Dubert, J; Fernández-Pardo, A; Nóvoa, S; Barja, J L; Prado, S

    2015-06-01

    Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. Two phytoplankton production systems were sampled weekly throughout 1-year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock. © 2015 The Society for Applied Microbiology.

  20. Effect of Climate Change on the Concentration and Associated Risks of Vibrio Spp. in Dutch Recreational Waters

    NARCIS (Netherlands)

    Sterk, Ankie; Schets, Franciska M; de Roda Husman, Ana Maria; de Nijs, Ton; Schijven, Jack F; de Roda Husman, Ana Maria

    2015-01-01

    Currently, the number of reported cases of recreational- water-related Vibrio illness in the Netherlands is low. However, a notable higher incidence of Vibrio infections has been observed in warm summers. In the future, such warm summers are expected to occur more often, resulting in enhanced water

  1. Effect of Climate Change on the Concentration and Associated Risks of Vibrio Spp. in Dutch Recreational Waters.

    Science.gov (United States)

    Sterk, Ankie; Schets, Franciska M; de Roda Husman, Ana Maria; de Nijs, Ton; Schijven, Jack F

    2015-09-01

    Currently, the number of reported cases of recreational- water-related Vibrio illness in the Netherlands is low. However, a notable higher incidence of Vibrio infections has been observed in warm summers. In the future, such warm summers are expected to occur more often, resulting in enhanced water temperatures favoring Vibrio growth. Quantitative information on the increase in concentration of Vibrio spp. in recreational water under climate change scenarios is lacking. In this study, data on occurrence of Vibrio spp. at six different bathing sites in the Netherlands (2009-2012) were used to derive an empirical formula to predict the Vibrio concentration as a function of temperature, salinity, and pH. This formula was used to predict the effects of increased temperatures in climate change scenarios on Vibrio concentrations. For Vibrio parahaemolyticus, changes in illness risks associated with the changed concentrations were calculated as well. For an average temperature increase of 3.7 °C, these illness risks were calculated to be two to three times higher than in the current situation. Current illness risks were, varying per location, on average between 10(-4) and 10(-2) per person for an entire summer. In situations where water temperatures reached maximum values, illness risks are estimated to be up to 10(-2) and 10(-1) . If such extreme situations occur more often during future summers, increased numbers of ill bathers or bathing-water-related illness outbreaks may be expected. © 2015 Society for Risk Analysis.

  2. Evidence for Cleavage of the Metalloprotease Vsm from Vibrio splendidus Strain JZ6 by an M20 Peptidase (PepT-like Protein) at Low Temperature.

    Science.gov (United States)

    Liu, Rui; Qiu, Limei; Cheng, Qi; Zhang, Huan; Wang, Lingling; Song, Linsheng

    2016-01-01

    Metalloprotease Vsm is a major extracellular virulence factor of Vibrio splendidus. The toxicity of Vsm from V. splendidus strain JZ6 has been characterized, and production of this virulence factor proved to be temperature-regulated. The present study provides evidence that two forms (JZE1 and JZE2) of Vsm protein exist in extracellular products (ECPs) of strain JZ6, and a significant conversion of these two forms was detected by SDS-PAGE and immunoblotting analyses of samples obtained from cells grown at 4, 10, 16, 20, 24, and 28°C. Mass spectroscopy confirmed that JZE1 was composed only of the peptidase_M4 domain of Vsm, and JZE2 contained both the PepSY domain and the peptidase_M4 domain. An M20 peptidase T-like protein (PepTL) was screened from the transcriptome data of strain JZ6, which was considered as a crucial molecule to produce the active Vsm (JZE1) by cleavage of the propeptide. Similar to that of Vsm, PepTL mRNA accumulation was highest at 4°C (836.82-fold of that at 28°C), decreased with increasing of temperature and reached its lowest level at 28°C. Deletion of the gene encoding the PepTL resulted in a mutant strain that did not produce the JZE1 cleavage product. The peptidase activity of PepTL recombinant protein (rPepTL) was confirmed by cleaving the Vsm in ECPs with an in vitro degradation reaction. These results demonstrate that PepTL participates in activating Vsm in strain JZ6 by proteolytic cleavage at low temperature.

  3. Cellulose effects on morphology and elasticity of Vibrio fischeri biofilms.

    Science.gov (United States)

    Ziemba, Christopher; Shabtai, Yael; Piatkovsky, Maria; Herzberg, Moshe

    2016-01-01

    Cellulose effects on Vibrio fischeri biofilm morphology were tested for the wild-type and two of its isogenic mutants that either exhibit increased cellulose production or do not produce cellulose at all. Confocal laser scanning microscopy imaging of each biofilm revealed that total sessile volume increases with cellulose expression, but the size of colonies formed with cellulose was smaller, creating a more diffuse biofilm. These morphological differences were not attributed to variations in bacterial deposition, extracellular polymeric substances affinity to the surface or bacterial growth. A positive correlation was found between cellulose expression, Young's (elastic) modulus of the biofilm analyzed with atomic force microscope and shear modulus of the related extracellular polymeric substances layers analyzed with quartz crystal microbalance with dissipation monitoring. Cellulose production also correlated positively with concentrations of extracellular DNA. A significant negative correlation was observed between cellulose expression and rates of diffusion through the extracellular polymeric substances. The difference observed in biofilm morphology is suggested as a combined result of cellulose and likely extracellular DNA (i) increasing biofilm Young's modulus, making shear removal more difficult, and (ii) decreased diffusion rate of nutrients and wastes into and out of the biofilm, which effectively limits colony size.

  4. Genetic components of stringent response in Vibrio cholerae

    Science.gov (United States)

    Pal, Ritesh Ranjan; Das, Bhabatosh; Dasgupta, Shreya; Bhadra, Rupak K.

    2011-01-01

    Nutritional stress elicits stringent response in bacteria involving modulation of expression of several genes. This is mainly triggered by the intracellular accumulation of two small molecules, namely, guanosine 3’-diphosphate 5’-triphosphate and guanosine 3’,5’-bis(diphosphate), collectively called (p)ppGpp. Like in other Gram-negative bacteria, the cellular level of (p)ppGpp is maintained in Vibrio cholerae, the causative bacterial pathogen of the disease cholera, by the products of two genes relA and spoT. However, apart from relA and spoT, a novel gene relV has recently been identified in V. cholerae, the product of which has been shown to be involved in (p)ppGpp synthesis under glucose or fatty acid starvation in a ΔrelA ΔspoT mutant background. Furthermore, the GTP binding essential protein CgtA and a non-DNA binding transcription factor DksA also seem to play several important roles in modulating stringent response and regulation of other genes in this pathogen. The present review briefly discusses about the role of all these genes mainly in the management of stringent response in V. cholerae. PMID:21415497

  5. Mutation of Bacterium Vibrio gazogenes for Selective Preparation of Colorants

    Science.gov (United States)

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D.; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples showed that two new main colorants as well as three previously found ones were produced. Liquid chromatography electro spray ionization mass spectrometry (LC-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic techniques were used to elucidate the structures of the newly produced colorants. Mass measurements revealed that the colorants C1, C2, C3, C4 have molecular masses of 321, 323, 351, and 295 Da. One unstable colorant C5 with molecular mass of 309 Da was detected as well. The mutated bacteria strains increased the yield of pigment production by about 81% and produced prodigiosin in 97% purity. The antibiotic activities of pure colorants are discussed as well. Based on their bio-activity and excellent dyeing capabilities, these colorants could be employed in cosmetic and textile industries. PMID:19902486

  6. Mutation of bacterium Vibrio gazogenes for selective preparation of colorants.

    Science.gov (United States)

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples showed that two new main colorants as well as three previously found ones were produced. Liquid chromatography electro spray ionization mass spectrometry (LC-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic techniques were used to elucidate the structures of the newly produced colorants. Mass measurements revealed that the colorants C1, C2, C3, C4 have molecular masses of 321, 323, 351, and 295 Da. One unstable colorant C5 with molecular mass of 309 Da was detected as well. The mutated bacteria strains increased the yield of pigment production by about 81% and produced prodigiosin in 97% purity. The antibiotic activities of pure colorants are discussed as well. Based on their bio-activity and excellent dyeing capabilities, these colorants could be employed in cosmetic and textile industries.

  7. The association between non-biting midges and Vibrio cholerae.

    Science.gov (United States)

    Broza, Meir; Gancz, Hanan; Kashi, Yechezkel

    2008-12-01

    Vibrio cholerae is a natural inhabitant of aquatic ecosystems, yet its interactions within this habitat are poorly understood. Here we describe the current knowledge on the interaction of V. cholerae with one group of co-inhabitants, the chironomids. Chironomids, non-biting midges (Chironomidae, Diptera), are an abundant macroinvertebrate group encountered in freshwater aquatic habitats. As holometabolous insects, chironomids start life when their larvae hatch from eggs laid at the water/air interface; through various feeding strategies, the larvae grow and pupate to become short-lived, non-feeding, adult flying insects. The discovery of the connection between V. cholerae and chironomids was accidental. While working with Chironomus transavaalensis, we observed the disintegration of its egg masses and searched for a possible microbial agent. We identified V. cholerae as the primary cause of this phenomenon. Haemagglutinin/protease, a secreted extracellular enzyme, degraded the gelatinous matrix surrounding the eggs, enabling bacterial growth. Observation of chironomids in relation to V. cholerae continuously for 7 years in various types of water bodies in Israel, India, and Africa revealed that environmental V. cholerae adhere to egg-mass surfaces of various Chironomini ('bloodworms'). The flying adults' potential to serve as mechanical vectors of V. cholerae from one water body to another was established. This, in turn, suggested that these insects play a role in the ecology of V. cholerae and possibly take part in the dissemination of the pathogenic serogroups during, and especially between, epidemics.

  8. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Carla eLutz

    2013-12-01

    Full Text Available It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium could be detected in areas where it had not been isolated from before, indicating a much broader, global distribution of this bacterium rather than specifically within regions where cholera is endemic. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of the bacterium in the sometimes hostile environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists.

  9. Vibrio cholerae: A historical perspective and current trend

    Directory of Open Access Journals (Sweden)

    Mary Oyenike Oladokun