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Sample records for cholerae cytolysin promotes

  1. The Vibrio cholerae cytolysin (VCC) promotes activation of mast cell (T helper 2) cytokine production

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    Arcidiacono, Diletta; Odom, Sandra; Frossi, Barbara; Rivera, Juan; Paccani, Silvia Rossi; Baldari, Cosima T.; Pucillo, Carlo; Montecucco, Cesare; de Bernard, Marina

    2008-01-01

    Summary Many strains of Vibrio cholerae produce a cytolysin (VCC) that forms oligomeric transmembrane pores responsible for vacuolization of several cell types in culture. Here we report that VCC is a TLR2 agonist able to stimulate mast cells to produce several cytokines (IL-4 included) which could contribute to the Th2 response seen in the natural infection. Moreover, VCC-induced cytokine production was dependent on increased cytosolic Ca2+ and on the presence of the two Src family kinases Lyn and Fyn, known to be required for FcεRI-dependent activation of mast cells. These findings strongly suggest that VCC is endowed with pro-inflammatory activity that promotes a Th2-type immune profile. PMID:18005391

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

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    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.

  3. Outer membrane vesicles mediate transport of biologically active Vibrio cholerae cytolysin (VCC from V. cholerae strains.

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    Sridhar Elluri

    Full Text Available Outer membrane vesicles (OMVs released from Gram-negative bacteria can serve as vehicles for the translocation of virulence factors. Vibrio cholerae produce OMVs but their putative role in translocation of effectors involved in pathogenesis has not been well elucidated. The V. cholerae cytolysin (VCC, is a pore-forming toxin that lyses target eukaryotic cells by forming transmembrane oligomeric β-barrel channels. It is considered a potent toxin that contributes to V. cholerae pathogenesis. The mechanisms involved in the secretion and delivery of the VCC have not been extensively studied.OMVs from V. cholerae strains were isolated and purified using a differential centrifugation procedure and Optiprep centrifugation. The ultrastructure and the contents of OMVs were examined under the electron microscope and by immunoblot analyses respectively. We demonstrated that VCC from V. cholerae strain V:5/04 was secreted in association with OMVs and the release of VCC via OMVs is a common feature among V. cholerae strains. The biological activity of OMV-associated VCC was investigated using contact hemolytic assay and epithelial cell cytotoxicity test. It showed toxic activity on both red blood cells and epithelial cells. Our results indicate that the OMVs architecture might play a role in stability of VCC and thereby can enhance its biological activities in comparison with the free secreted VCC. Furthermore, we tested the role of OMV-associated VCC in host cell autophagy signalling using confocal microscopy and immunoblot analysis. We observed that OMV-associated VCC triggered an autophagy response in the target cell and our findings demonstrated for the first time that autophagy may operate as a cellular defence mechanism against an OMV-associated bacterial virulence factor.Biological assays of OMVs from the V. cholerae strain V:5/04 demonstrated that OMV-associated VCC is indeed biologically active and induces toxicity on mammalian cells and

  4. 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.

  5. Revisiting the oligomerization mechanism of Vibrio cholerae cytolysin, a beta-barrel pore-forming toxin.

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    Rai, Anand Kumar; Chattopadhyay, Kausik

    2016-06-03

    Vibrio cholerae cytolysin (VCC) is a membrane-damaging beta-barrel pore-forming toxin (beta-PFT). VCC causes permeabilization of the target membranes by forming transmembrane oligomeric beta-barrel pores. Oligomerization is a key step in the mode of action of any beta-PFT, including that of VCC. Earlier studies have identified some of the key residues in VCC that are directly involved in the generation of the inter-protomer contacts, thus playing critical roles in the oligomerization of the membrane-bound toxin. Analysis of the VCC oligomeric pore structure reveals a potential hydrogen-bond network that appears to connect the sidechain of an asparagine residue (Asn582; located within an inter-domain linker sequence) from one protomer to the backbone CO- and NH-groups of the neighbouring protomer, indirectly through water molecules at most of the inter-protomer interfaces. In the present study, we show that the mutation of Asn582Ala affects the oligomerization and the pore-forming activity of VCC in the membrane lipid bilayer of the synthetic lipid vesicles, while the replacement of Asn582Gln results into the restoration of the oligomeric pore-forming ability of the toxin. Using a number of truncated variants of VCC, having deletion in the C-terminal region of the toxin starting from the Asn582 residue or beyond, we also show that the presence of Asn582 is critically required for the oligomerization of the truncated form of the protein.

  6. Revisiting the membrane interaction mechanism of a membrane-damaging β-barrel pore-forming toxin Vibrio cholerae cytolysin.

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    Rai, Anand Kumar; Chattopadhyay, Kausik

    2015-09-01

    Vibrio cholerae cytolysin (VCC) permeabilizes target cell membranes by forming transmembrane oligomeric β-barrel pores. VCC has been shown to associate with the target membranes via amphipathicity-driven spontaneous partitioning into the membrane environment. More specific interaction(s) of VCC with the membrane components have also been documented. In particular, specific binding of VCC with the membrane lipid components is believed to play a crucial role in determining the efficacy of the pore-formation process. However, the structural basis and the functional implications of the VCC interaction with the membrane lipids remain unclear. Here we show that the distinct loop sequences within the membrane-proximal region of VCC play critical roles to determine the functional interactions of the toxin with the membrane lipids. Alterations of the loop sequences via structure-guided mutagenesis allow amphipathicity-driven partitioning of VCC to the membrane lipid bilayer. Alterations of the loop sequences, however, block specific interactions of VCC with the membrane lipids and abort the oligomerization, membrane insertion, pore-formation and cytotoxic activity of the toxin. Present study identifies the structural signatures in VCC implicated for its functional interactions with the membrane lipid components, a process that presumably acts to drive the subsequent steps of the oligomeric β-barrel pore-formation and cytotoxic responses.

  7. Transmembrane oligomeric form of Vibrio cholerae cytolysin triggers TLR2/TLR6-dependent proinflammatory responses in monocytes and macrophages.

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    Khilwani, Barkha; Mukhopadhaya, Arunika; Chattopadhyay, Kausik

    2015-02-15

    Vibrio cholerae cytolysin (VCC) kills target eukaryotic cells by forming transmembrane oligomeric β-barrel pores. Once irreversibly converted into the transmembrane oligomeric form, VCC acquires an unusual structural stability and loses its cytotoxic property. It is therefore possible that, on exertion of its cytotoxic activity, the oligomeric form of VCC retained in the disintegrated membrane fractions of the lysed cells would survive within the host cellular milieu for a long period, without causing any further cytotoxicity. Under such circumstances, VCC oligomers may potentially be recognized by the host immune cells. Based on such a hypothesis, in the present study we explored the interaction of the transmembrane oligomeric form of VCC with the monocytes and macrophages of the innate immune system. Our study shows that the VCC oligomers assembled in the liposome membranes elicit potent proinflammatory responses in monocytes and macrophages, via stimulation of the toll-like receptor (TLR)2/TLR6-dependent signalling cascades that involve myeloid differentiation factor 88 (MyD88)/interleukin-1-receptor-associated kinase (IRAK)1/tumour-necrosis-factor-receptor-associated factor (TRAF)6. VCC oligomer-mediated proinflammatory responses critically depend on the activation of the transcription factor nuclear factor-κB. Proinflammatory responses induced by the VCC oligomers also require activation of the mitogen-activated protein kinase (MAPK) family member c-Jun N-terminal kinase, which presumably acts via stimulation of the transcription factor activator protein-1. Notably, the role of the MAPK p38 could not be documented in the process.

  8. Pre-pore oligomer formation by Vibrio cholerae cytolysin: insights from a truncated variant lacking the pore-forming pre-stem loop.

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    Paul, Karan; Chattopadhyay, Kausik

    2014-01-03

    Vibrio cholerae cytolysin (VCC), a β-barrel pore-forming toxin (β-PFT), induces killing of the target eukaryotic cells by forming heptameric transmembrane β-barrel pores. Consistent with the β-PFT mode of action, binding of the VCC toxin monomers with the target cell membrane triggers formation of pre-pore oligomeric intermediates, followed by membrane insertion of the β-strands contributed by the pre-stem motif within the central cytolysin domain of each protomer. It has been shown previously that blocking of membrane insertion of the VCC pre-stem motif arrests conversion of the pre-pore state to the functional transmembrane pore. Consistent with the generalized β-PFT mechanism, it therefore appears that the VCC pre-stem motif plays a critical role toward forming the structural scaffold of the transmembrane β-barrel pore. It is, however, still not known whether the pre-stem motif plays any role in the membrane interaction process, and subsequent pre-pore structure formation by VCC. In this direction, we have constructed a recombinant variant of VCC deleting the pre-stem region, and have characterized the effect(s) of physical absence of the pre-stem motif on the distinct steps of the membrane pore-formation process. Our results show that the deletion of the pre-stem segment does not affect membrane binding and pre-pore oligomer formation by the toxin, but it critically abrogates the functional pore-forming activity of VCC. Present study extends our insights regarding the structure-function mechanism associated with the membrane pore formation by VCC, in the context of the β-PFT mode of action.

  9. Trapping of Vibrio cholerae cytolysin in the membrane-bound monomeric state blocks membrane insertion and functional pore formation by the toxin.

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    Rai, Anand Kumar; Chattopadhyay, Kausik

    2014-06-13

    Vibrio cholerae cytolysin (VCC) is a potent membrane-damaging cytolytic toxin that belongs to the family of β barrel pore-forming protein toxins. VCC induces lysis of its target eukaryotic cells by forming transmembrane oligomeric β barrel pores. The mechanism of membrane pore formation by VCC follows the overall scheme of the archetypical β barrel pore-forming protein toxin mode of action, in which the water-soluble monomeric form of the toxin first binds to the target cell membrane, then assembles into a prepore oligomeric intermediate, and finally converts into the functional transmembrane oligomeric β barrel pore. However, there exists a vast knowledge gap in our understanding regarding the intricate details of the membrane pore formation process employed by VCC. In particular, the membrane oligomerization and membrane insertion steps of the process have only been described to a limited extent. In this study, we determined the key residues in VCC that are critical to trigger membrane oligomerization of the toxin. Alteration of such key residues traps the toxin in its membrane-bound monomeric state and abrogates subsequent oligomerization, membrane insertion, and functional transmembrane pore-formation events. The results obtained from our study also suggest that the membrane insertion of VCC depends critically on the oligomerization process and that it cannot be initiated in the membrane-bound monomeric form of the toxin. In sum, our study, for the first time, dissects membrane binding from the subsequent oligomerization and membrane insertion steps and, thus, defines the exact sequence of events in the membrane pore formation process by VCC.

  10. Physicochemical constraints of elevated pH affect efficient membrane interaction and arrest an abortive membrane-bound oligomeric intermediate of the beta-barrel pore-forming toxin Vibrio cholerae cytolysin.

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    Rai, Anand Kumar; Kundu, Nidhi; Chattopadhyay, Kausik

    2015-10-01

    Vibrio cholerae cytolysin (VCC) is a potent membrane-damaging cytotoxic protein. VCC causes permeabilization of the target cell membranes by forming transmembrane oligomeric beta-barrel pores. Membrane pore formation by VCC involves following key steps: (i) membrane binding, (ii) formation of a pre-pore oligomeric intermediate, (iii) membrane insertion of the pore-forming motifs, and (iv) formation of the functional transmembrane pore. Membrane binding, oligomerization, and subsequent pore-formation process of VCC appear to be facilitated by multiple regulatory mechanisms that are only partly understood. Here, we have explored the role(s) of the physicochemical constraints, specifically imposed by the elevated pH conditions, on the membrane pore-formation mechanism of VCC. Elevated pH abrogates efficient interaction of VCC with the target membranes, and blocks its pore-forming activity. Under the elevated pH conditions, membrane-bound fractions of VCC remain trapped in the form of abortive oligomeric species that fail to generate the functional transmembrane pores. Such an abortive oligomeric assembly appears to represent a distinct, more advanced intermediate state than the pre-pore state. The present study offers critical insights regarding the implications of the physicochemical constraints for regulating the efficient membrane interaction and pore formation by VCC.

  11. Promoter activities in Vibrio cholerae ctx phi prophage.

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    Fando, R; Pérez, J L; Rodriguez, B L; Campos, J; Robert, A; García, L; Silva, A; Benitez, J A

    1997-04-01

    Comparison of cholera toxin (CT) production directed by different gene constructs and S1 nuclease mapping revealed the presence of a ctxB-specific promoter within the ctxA coding sequence. Initiation of transcription in this region occurred in wild-type El Tor and classical biotype choleragenic vibrios. We propose that transcription from the ctxB-specific promoter and a stronger ribosomal binding site on the ctxB mRNA synergistically contribute to achieve the correct (5B:1A) subunit stoichiometry. Plasmid pB, a CT promoterless vector expressing only CTB, was used to detect promoter activity by restoration of A-subunit synthesis. Promoter activity expressed in vitro and in vivo was detected upstream of the zonula occludens toxin gene, suggesting that this factor could be produced in vivo to contribute to fluid accumulation. No promoter activity was detected in vitro and in vivo upstream from the accessory cholera enterotoxin gene.

  12. Cholera

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    Harris, Jason B.; LaRocque, Regina C; Qadri, Firdausi; Edward T. Ryan; Calderwood, Stephen B.

    2012-01-01

    Cholera is an acute, secretory diarrhea caused by infection with Vibrio cholerae of the O1 and O139 serogroups. Cholera is endemic in over 50 countries and also causes large epidemics. Since 1817, seven cholera pandemics have spread from Asia to much of the world. The 7th pandemic began in 1961 and affects 3–5 million people each year, killing 120,000. Although mild cholera may be indistinguishable from other diarrheal illnesses, the presentation of severe cholera is distinct, with dramatic d...

  13. Cholera.

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    Lippi, Donatella; Gotuzzo, Eduardo; Caini, Saverio

    2016-08-01

    Cholera is an acute disease of the gastrointestinal tract caused by Vibrio cholerae. Cholera was localized in Asia until 1817, when a first pandemic spread from India to several other regions of the world. After this appearance, six additional major pandemics occurred during the 19th and 20th centuries, the latest of which originated in Indonesia in the 1960s and is still ongoing. In 1854, a cholera outbreak in Soho, London, was investigated by the English physician John Snow (1813 to 1858). He described the time course of the outbreak, managed to understand its routes of transmission, and suggested effective measures to stop its spread, giving rise to modern infectious disease epidemiology. The germ responsible for cholera was discovered twice: first by the Italian physician Filippo Pacini during an outbreak in Florence, Italy, in 1854, and then independently by Robert Koch in India in 1883, thus favoring the germ theory over the miasma theory of disease. Unlike many other infectious diseases, such as plague, smallpox, and poliomyelitis, cholera persists as a huge public health problem worldwide, even though there are effective methods for its prevention and treatment. The main reasons for its persistence are socioeconomic rather than purely biological; cholera flourishes where there are unsatisfactory hygienic conditions and where a breakdown of already fragile sanitation and health infrastructure occurs because of natural disasters or humanitarian crises.

  14. The β-prism lectin domain of Vibrio cholerae hemolysin promotes self-assembly of the β-pore-forming toxin by a carbohydrate-independent mechanism.

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    Ganguly, Sreerupa; Mukherjee, Amarshi; Mazumdar, Budhaditya; Ghosh, Amar N; Banerjee, Kalyan K

    2014-02-14

    Vibrio cholerae cytolysin/hemolysin (VCC) is an amphipathic 65-kDa β-pore-forming toxin with a C-terminal β-prism lectin domain. Because deletion or point mutation of the lectin domain seriously compromises hemolytic activity, it is thought that carbohydrate-dependent interactions play a critical role in membrane targeting of VCC. To delineate the contributions of the cytolysin and lectin domains in pore formation, we used wild-type VCC, 50-kDa VCC (VCC(50)) without the lectin domain, and mutant VCC(D617A) with no carbohydrate-binding activity. VCC and its two variants with no carbohydrate-binding activity moved to the erythrocyte stroma with apparent association constants on the order of 10(7) M(-1). However, loss of the lectin domain severely reduced the efficiency of self-association of the VCC monomer with the β-barrel heptamer in the synthetic lipid bilayer from ∼83 to 27%. Notably, inactivation of the carbohydrate-binding activity by the D617A mutation marginally reduced oligomerization to ∼77%. Oligomerization of VCC(50) was temperature-insensitive; by contrast, VCC self-assembly increased with increasing temperature, suggesting that the process is driven by entropy and opposed by enthalpy. Asialofetuin, the β1-galactosyl-terminated glycoprotein inhibitor of VCC-induced hemolysis, promoted oligomerization of 65-kDa VCC to a species that resembled the membrane-inserted heptamer in stoichiometry and morphology but had reduced global amphipathicity. In conclusion, we propose (i) that the β-prism lectin domain facilitated toxin assembly by producing entropy during relocation in the heptamer and (ii) that glycoconjugates inhibited VCC by promoting its assembly to a water-soluble, less amphipathic oligomer variant with reduced ability to penetrate the bilayer.

  15. Prevention and promotion is the cornerstone in the effort to erradicate cholera in primary care

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    Yurieth Gallardo

    2013-10-01

    Full Text Available Introduction. Cholera has accompanied mankind since time immemorial with historical records from China, India and ancient Greece. However, registers are available only since 1817, when the first documented pandemic emerged in Asia and spread to Turkey and Arab countries. Since then, eight episodes of cholera pandemic have occurred in the world. Objective. To inform the scientific community about the epidemiological situation in the province of Granma, Cuba, at the cross-sectional period of July 2012 and the prevention and health promotion measures that were introduced in the first level of care for cases of diarrhea caused by Vibrio cholerae. These measures were implemented in the territory with an intersectoral approach, resulting in the adoption of healthy lifestyles by the general population. Conclusion. Basic sanitation activities were undertaken to slow the spread of the disease, complemented by suggestions to the medical community about the importance of epidemiological surveillance to detect reemergence.

  16. Promotion of Cholera Awareness Among Households of Cholera Patients: A Randomized Controlled Trial of the Cholera-Hospital-Based-Intervention-for-7 Days (CHoBI7) Intervention.

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    Saif-Ur-Rahman, K M; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Rashid, Mahamud-Ur; Biswas, Shwapon Kumar; Sack, David; Sack, R Bradley; Monira, Shirajum; Alam, Munirul; Shaly, Nusrat Jahan; George, Christine Marie

    2016-12-07

    Previous studies have demonstrated that household contacts of cholera patients are highly susceptible to cholera infections for a 7-day period after the presentation of the index patient in the hospital. However, there is no standard of care to prevent cholera transmission in this high-risk population. Furthermore, there is limited information available on awareness of cholera transmission and prevention among cholera patients and their household contacts. To initiate a standard of care for this high-risk population, we developed the Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which delivers a handwashing with soap and water treatment intervention to household contacts during the time they spend with the admitted cholera patient in the hospital and reinforces these messages through home visits. To test CHoBI7, we conducted a randomized controlled trial among 302 intervention cholera patient household members and 302 control cholera patient household members in Dhaka, Bangladesh. In this study, we evaluated the effectiveness of the CHoBI7 intervention in increasing awareness of cholera transmission and prevention, and the key times for handwashing with soap. We observed a significant increase in cholera knowledge score in the intervention arm compared with the control arm at both the 1-week follow-up {score coefficient = 2.34 (95% confidence interval [CI] = 1.96, 2.71)} and 6 to 12-month follow-up period (score coefficient = 1.59 [95% CI = 1.05, 2.13]). This 1-week hospital- and home-based intervention led to a significant increase in knowledge of cholera transmission and prevention which was sustained 6 to 12 months post-intervention. These findings suggest that the CHoBI7 intervention presents a promising approach to increase cholera awareness among this high-risk population.

  17. Dual Zinc Transporter Systems in Vibrio cholerae Promote Competitive Advantages over Gut Microbiome.

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    Sheng, Ying; Fan, Fenxia; Jensen, Owen; Zhong, Zengtao; Kan, Biao; Wang, Hui; Zhu, Jun

    2015-10-01

    Zinc is an essential trace metal required for numerous cellular processes in all forms of life. In order to maintain zinc homeostasis, bacteria have developed several transport systems to regulate its uptake. In this study, we investigated zinc transport systems in the enteric pathogen Vibrio cholerae, the causative agent of cholera. Bioinformatic analysis predicts that two gene clusters, VC2081 to VC2083 (annotated as zinc utilization genes znuABC) and VC2551 to VC2555 (annotated as zinc-regulated genes zrgABCDE), are regulated by the putative zinc uptake regulator Zur. Using promoter reporter and biochemical assays, we confirmed that Zur represses znuABC and zrgABCDE promoters in a Zn(2+)-dependent manner. Under Zn(2+)-limiting conditions, we found that mutations in either the znuABC or zrgABCDE gene cluster affect bacterial growth, with znuABC mutants displaying a more severe growth defect, suggesting that both ZnuABC and ZrgABCDE are involved in Zn(2+) uptake and that ZnuABC plays the predominant role. Furthermore, we reveal that ZnuABC and ZrgABCDE are important for V. cholerae colonization in both infant and adult mouse models, particularly in the presence of other intestinal microbiota. Collectively, our studies indicate that these two zinc transporter systems play vital roles in maintaining zinc homeostasis during V. cholerae growth and pathogenesis.

  18. Bicarbonate increases binding affinity of Vibrio cholerae ToxT to virulence gene promoters.

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    Thomson, Joshua J; Withey, Jeffrey H

    2014-11-01

    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.

  19. The superintegron integrase and the cassette promoters are co-regulated in Vibrio cholerae.

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    Evelyne Krin

    Full Text Available Chromosome 2 of Vibrio cholerae carries a chromosomal superintegron, composed of an integrase, a cassette integration site (attI and an array of mostly promoterless gene cassettes. We determined the precise location of the promoter, Pc, which drives the transcription of the first cassettes of the V. cholerae superintegron. We found that cassette mRNA starts 65 bp upstream of the attI site, so that the inversely oriented promoters Pc and Pint (integrase promoter partly overlap, allowing for their potential co-regulation. Pint was previously shown to be induced during the SOS response and is further controlled by the catabolite repression cAMP-CRP complex. We found that cassette expression from Pc was also controlled by the cAMP-CRP complex, but is not part of the SOS regulon. Pint and Pc promoters were both found to be induced in rich medium, at high temperature, high salinity and at the end of exponential growth phase, although at very different levels and independently of sigma factor RpoS. All these results show that expression from the integrase and cassette promoters can take place at the same time, thus leading to coordinated excisions and integrations within the superintegron and potentially coupling cassette shuffling to immediate selective advantage.

  20. Host intestinal signal-promoted biofilm dispersal induces Vibrio cholerae colonization.

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    Hay, Amanda J; Zhu, Jun

    2015-01-01

    Vibrio cholerae causes human infection through ingestion of contaminated food and water, leading to the devastating diarrheal disease cholera. V. cholerae forms matrix-encased aggregates, known as biofilms, in the native aquatic environment. While the formation of V. cholerae biofilms has been well studied, little is known about the dispersal from biofilms, particularly upon entry into the host. In this study, we found that the exposure of mature biofilms to physiologic levels of the bile salt taurocholate, a host signal for the virulence gene induction of V. cholerae, induces an increase in the number of detached cells with a concomitant decrease in biofilm mass. Scanning electron microscopy micrographs of biofilms exposed to taurocholate revealed an altered, perhaps degraded, appearance of the biofilm matrix. The inhibition of protein synthesis did not alter rates of detachment, suggesting that V. cholerae undergoes a passive dispersal. Cell-free media from taurocholate-exposed biofilms contains a larger amount of free polysaccharide, suggesting an abiotic degradation of biofilm matrix by taurocholate. Furthermore, we found that V. cholerae is only able to induce virulence in response to taurocholate after exit from the biofilm. Thus, we propose a model in which V. cholerae ingested as a biofilm has coopted the host-derived bile salt signal to detach from the biofilm and go on to activate virulence.

  1. Promotion of colonization and virulence by cholera toxin is dependent on neutrophils.

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    Queen, Jessica; Satchell, Karla J F

    2013-09-01

    The innate immune response to Vibrio cholerae infection is poorly understood, but this knowledge is critical for the design of safe, effective vaccines. Using an adult mouse intestinal infection model, this study examines the contribution of neutrophils to host immunity, as well as the effect of cholera toxin and other secreted factors on this response. Depletion of neutrophils from mice with anti-Ly6G IA8 monoclonal antibody led to similar survival rates of mice infected with low or moderate doses of toxigenic V. cholerae El Tor O1. At a high dose, neutropenic mice showed increased rates of survival compared to neutrophil-replete animals. Expression of cholera toxin was found to be protective to the neutropenic host, and this phenotype can be replicated by the administration of purified toxin. Neutrophils do not effectively clear colonizing bacteria from the small intestine, nor do they alter induction of early immune-modulating signals. In both neutropenic and neutrophil-replete animals, the local response to infection is characterized by expression of interleukin 6 (IL-6), IL-10, and macrophage inflammatory protein 2 alpha (MIP-2). Overall, these data indicate that the innate immune response to toxigenic V. cholerae infection differs dramatically from the host response to nontoxigenic infection or vaccination, where neutrophils are protective to the host. In the absence of neutrophils, cholera toxin induces immunomodulatory effects that increase host survival. In cholera toxin-producing strains, similar to nontoxigenic infection, accessory toxins are critical to virulence, indicating that cholera toxin and the other secreted toxins modulate the host response by different mechanisms, with both contributing to bacterial persistence and virulence.

  2. Oral administration of a recombinant cholera toxin B subunit promotes mucosal healing in the colon.

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    Baldauf, K J; Royal, J M; Kouokam, J C; Haribabu, B; Jala, V R; Yaddanapudi, K; Hamorsky, K T; Dryden, G W; Matoba, N

    2016-11-02

    Cholera toxin B subunit (CTB) is a component of a licensed oral cholera vaccine. However, CTB has pleiotropic immunomodulatory effects whose impacts on the gut are not fully understood. Here, we found that oral administration in mice of a plant-made recombinant CTB (CTBp) significantly increased several immune cell populations in the colon lamina propria. Global gene expression analysis revealed that CTBp had more pronounced impacts on the colon than the small intestine, with significant activation of TGFβ-mediated pathways in the colon epithelium. The clinical relevance of CTBp-induced impacts on colonic mucosa was examined. In a human colon epithelial model using Caco2 cells, CTBp, but not the non-GM1-binding mutant G33D-CTBp, induced TGFβ-mediated wound healing. In a dextran sodium sulfate (DSS) acute colitis mouse model, oral administration of CTBp protected against colon mucosal damage as manifested by mitigated body weight loss, decreased histopathological scores, and blunted escalation of inflammatory cytokine levels while inducing wound healing-related genes. Furthermore, biweekly oral administration of CTBp significantly reduced disease severity and tumorigenesis in the azoxymethane/DSS model of ulcerative colitis and colon cancer. Altogether, these results demonstrate CTBp's ability to enhance mucosal healing in the colon, highlighting its potential application in ulcerative colitis therapy besides cholera vaccination.Mucosal Immunology advance online publication 2 November 2016. doi:10.1038/mi.2016.95.

  3. Structure, Function, and Biology of the Enterococcus faecalis Cytolysin

    Directory of Open Access Journals (Sweden)

    Daria Van Tyne

    2013-04-01

    Full Text Available Enterococcus faecalis is a Gram-positive commensal member of the gut microbiota of a wide range of organisms. With the advent of antibiotic therapy, it has emerged as a multidrug resistant, hospital-acquired pathogen. Highly virulent strains of E. faecalis express a pore-forming exotoxin, called cytolysin, which lyses both bacterial and eukaryotic cells in response to quorum signals. Originally described in the 1930s, the cytolysin is a member of a large class of lanthionine-containing bacteriocins produced by Gram-positive bacteria. While the cytolysin shares some core features with other lantibiotics, it possesses unique characteristics as well. The current understanding of cytolysin biosynthesis, structure/function relationships, and contribution to the biology of E. faecalis are reviewed, and opportunities for using emerging technologies to advance this understanding are discussed.

  4. Partial characterization of a Moraxella bovis cytolysin.

    Science.gov (United States)

    Gray, J T; Fedorka-Cray, P J; Rogers, D G

    1995-02-01

    Moraxella bovis (M. bovis) is the etiologic agent of infectious bovine keratoconjunctivitis and M. bovis hemolysin is believed to be an important virulence factor. Two strains of M. bovis were compared, Epp 63(300) (Epp), a known virulent and hemolytic strain, and IBH 63 (IBH), a known avirulent and nonhemolytic strain. Sterile 10-fold (10x) supernatant concentrates were obtained from cultures grown in TSB broth with 10 mM CaCl2. Supernatant hemolysin titers for Epp, were 1:1024 and 1:8192 for unconcentrated (1x) and 10x, respectively. Supernatant cytotoxin titers to bovine mononuclear cells were 1:32 and 1:128 for 1x and 10x, respectively, for Epp. Cytolytic (hemolytic and cytotoxic) activities declined 10-fold but were still measurable for > 1 wk at 4 degrees C. Both activities were inactivated by trypsin and by heating at 56 degrees C for 20 min. A cytotoxic effect was observed on cultured bovine and ovine corneal epithelial cells with Epp. All cytolytic effects were neutralized with antiserum to 10x Epp. No cytolytic activities were detected for 10x IBH. SDS-PAGE electrophoresis and related immunoblots indicate a high molecular weight protein at 110 kDa for the 10x Epp preparation when stained with silver or probed with monoclonal antibodies to the E. coli alpha hemolysin. No 110 kDa band is observed for 10x IBH. These data suggest that hemolytic and cytotoxic activities are important in the pathogenesis of infectious bovine keratoconjunctivitis and identify the protein as a possible RTX related toxin of 110 kDa. Stability of the M. bovis cytolysin for > 1 week should allow further characterization and purification of the protein.

  5. Widespread epidemic cholera caused by a restricted subset of Vibrio cholerae clones.

    Science.gov (United States)

    Moore, S; Thomson, N; Mutreja, A; Piarroux, R

    2014-05-01

    Since 1817, seven cholera pandemics have plagued humankind. As the causative agent, Vibrio cholerae, is autochthonous in the aquatic ecosystem and some studies have revealed links between outbreaks and fluctuations in climatic and aquatic conditions, it has been widely assumed that cholera epidemics are triggered by environmental factors that promote the growth of local bacterial reservoirs. However, mounting epidemiological findings and genome sequence analysis of clinical isolates have indicated that epidemics are largely unassociated with most of the V. cholerae strains in aquatic ecosystems. Instead, only a specific subset of V. cholerae El Tor 'types' appears to be responsible for current epidemics. A recent report examining the evolution of a variety of V. cholerae strains indicates that the current pandemic is monophyletic and originated from a single ancestral clone that has spread globally in successive waves. In this review, we examine the clonal nature of the disease, with the example of the recent history of cholera in the Americas. Epidemiological data and genome sequence-based analysis of V. cholerae isolates demonstrate that the cholera epidemics of the 1990s in South America were triggered by the importation of a pathogenic V. cholerae strain that gradually spread throughout the region until local outbreaks ceased in 2001. Latin America remained almost unaffected by the disease until a new toxigenic V. cholerae clone was imported into Haiti in 2010. Overall, cholera appears to be largely caused by a subset of specific V. cholerae clones rather than by the vast diversity of V. cholerae strains in the environment.

  6. Drinking cholera

    DEFF Research Database (Denmark)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin

    2015-01-01

    beconducive to V. cholerae survival. Furthermore, salinity levels of participant’s drinking water sourceswere all well below the levels required for optimal survival of V. cholerae. Respondents explainedthat they preferred less salty and more aesthetically pleasing drinking water. Conclusion: Theoretically, V...

  7. Single-molecule tracking in live Vibrio cholerae reveals that ToxR recruits the membrane-bound virulence regulator TcpP to the toxT promoter.

    Science.gov (United States)

    Haas, Beth L; Matson, Jyl S; DiRita, Victor J; Biteen, Julie S

    2015-04-01

    Vibrio cholerae causes the human disease cholera by producing a potent toxin. The V. cholerae virulence pathway involves an unusual transcription step: the bitopic inner-membrane proteins TcpP and ToxR activate toxT transcription. As ToxT is the primary direct transcription activator in V. cholerae pathogenicity, its regulation by membrane-localized activators is key in the disease process. However, the molecular mechanisms by which membrane-localized activators engage the transcription process have yet to be uncovered in live cells. Here we report the use of super-resolution microscopy, single-molecule tracking, and gene knockouts to examine the dynamics of individual TcpP proteins in live V. cholerae cells with cholerae to that in mutant strains lacking either toxR or the toxT promoter, we determine that TcpP mobility is greater in the presence of its interaction partners than in their absence. Our findings support a mechanism in which ToxR recruits TcpP to the toxT promoter for transcription activation.

  8. Cholera Toxin Promotes Th17 Cell Differentiation by Modulating Expression of Polarizing Cytokines and the Antigen-Presenting Potential of Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Jung-Ok Kang

    Full Text Available Cholera toxin (CT, an exotoxin produced by Vibrio cholera, acts as a mucosal adjuvant. In a previous study, we showed that CT skews differentiation of CD4 T cells to IL-17-producing Th17 cells. Here, we found that intranasal administration of CT induced migration of migratory dendritic cell (DC populations, CD103+ DCs and CD11bhi DCs, to the lung draining mediastinal lymph nodes (medLN. Among those DC subsets, CD11bhi DCs that were relatively immature had a major role in Th17 cell differentiation after administration of CT. CT-treated BMDCs showed reduced expression of MHC class II and CD86, similar to CD11bhi DCs in medLN, and these BMDCs promoted Th17 cell differentiation more potently than other BMDCs expressing higher levels of MHC class II and CD86. By analyzing the expression of activation markers such as CD25 and CD69, proliferation and IL-2 production, we determined that CT-treated BMDCs showed diminished antigen-presenting potential to CD4+ T cells compared with normal BMDCs. We also found that CT-stimulated BMDCs promote activin A expression as well as IL-6 and IL-1β, and activin A had a synergic role with TGF-β1 in CT-mediated Th17 cell differentiation. Taken together, our results suggest that CT-stimulated DCs promote Th17 cell differentiation by not only modulating antigen-presenting potential but also inducing Th polarizing cytokines.

  9. Cholera Toxin Promotes Th17 Cell Differentiation by Modulating Expression of Polarizing Cytokines and the Antigen-Presenting Potential of Dendritic Cells

    Science.gov (United States)

    Kang, Jung-Ok; Lee, Jee-Boong

    2016-01-01

    Cholera toxin (CT), an exotoxin produced by Vibrio cholera, acts as a mucosal adjuvant. In a previous study, we showed that CT skews differentiation of CD4 T cells to IL-17-producing Th17 cells. Here, we found that intranasal administration of CT induced migration of migratory dendritic cell (DC) populations, CD103+ DCs and CD11bhi DCs, to the lung draining mediastinal lymph nodes (medLN). Among those DC subsets, CD11bhi DCs that were relatively immature had a major role in Th17 cell differentiation after administration of CT. CT-treated BMDCs showed reduced expression of MHC class II and CD86, similar to CD11bhi DCs in medLN, and these BMDCs promoted Th17 cell differentiation more potently than other BMDCs expressing higher levels of MHC class II and CD86. By analyzing the expression of activation markers such as CD25 and CD69, proliferation and IL-2 production, we determined that CT-treated BMDCs showed diminished antigen-presenting potential to CD4+ T cells compared with normal BMDCs. We also found that CT-stimulated BMDCs promote activin A expression as well as IL-6 and IL-1β, and activin A had a synergic role with TGF-β1 in CT-mediated Th17 cell differentiation. Taken together, our results suggest that CT-stimulated DCs promote Th17 cell differentiation by not only modulating antigen-presenting potential but also inducing Th polarizing cytokines. PMID:27271559

  10. Cholera Treatment

    Science.gov (United States)

    ... Public Health in Haiti Haiti Pre-decision Brief Cholera in Haiti: One Year Later Related Links Healthy Water Global Water, Sanitation, & Hygiene (WASH) The Safe Water System Division of Foodborne, Waterborne, and Environmental Diseases Get Email Updates To receive email updates about ...

  11. What is cholera?

    DEFF Research Database (Denmark)

    Tamason, Charlotte Crim; Tulsiani, Suhella; Siddique, A.;

    2016-01-01

    a third ofthe respondents did not associate diarrhea with cholera or mentioned symptoms that could not be caused by cholera (29%). Approximately half of the respondents associated water with the cause of cholera (56%) and only 8% associated cholera with sanitation or hygiene. Shame and stigma (54%) were...

  12. 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.

  13. More Than a Pore: The Cellular Response to Cholesterol-Dependent Cytolysins

    Directory of Open Access Journals (Sweden)

    Sara K. B. Cassidy

    2013-04-01

    Full Text Available Targeted disruption of the plasma membrane is a ubiquitous form of attack used in all three domains of life. Many bacteria secrete pore-forming proteins during infection with broad implications for pathogenesis. The cholesterol-dependent cytolysins (CDC are a family of pore-forming toxins expressed predominately by Gram-positive bacterial pathogens. The structure and assembly of some of these oligomeric toxins on the host membrane have been described, but how the targeted cell responds to intoxication by the CDCs is not as clearly understood. Many CDCs induce lysis of their target cell and can activate apoptotic cascades to promote cell death. However, the extent to which intoxication causes cell death is both CDC- and host cell-dependent, and at lower concentrations of toxin, survival of intoxicated host cells is well documented. Additionally, the effect of CDCs can be seen beyond the plasma membrane, and it is becoming increasingly clear that these toxins are potent regulators of signaling and immunity, beyond their role in intoxication. In this review, we discuss the cellular response to CDC intoxication with emphasis on the effects of pore formation on the host cell plasma membrane and subcellular organelles and whether subsequent cellular responses contribute to the survival of the affected cell.

  14. Cholera Prevention and Control

    Science.gov (United States)

    ... name="commit" type="submit" value="Submit" /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention Control Topics Six Basic Cholera Prevention Messages I nfection ...

  15. What is cholera?

    DEFF Research Database (Denmark)

    Tamason, Charlotte Crim; Tulsiani, Suhella; Siddique, A.;

    2016-01-01

    Background: Cholera has afflicted the Indian sub-continent for centuries, predominantly in West Bengal and modern-day Bangladesh. This preliminary study aims to understand the current level of knowledge of cholera in female Bangladeshi caretakers, which is important in the outcome of the disease...... and its spread. A pilot study was conducted among 85 women in Bangladesh using qualitative questionnaires to explore the ability of female caretakers in identifying cholera and its transmission. Findings: The survey revealed that though all the female caretakers were aware of the term “cholera,” nearly...... a third ofthe respondents did not associate diarrhea with cholera or mentioned symptoms that could not be caused by cholera (29%). Approximately half of the respondents associated water with the cause of cholera (56%) and only 8% associated cholera with sanitation or hygiene. Shame and stigma (54%) were...

  16. The Enterococcus faecalis cytolysin: a novel toxin active against eukaryotic and prokaryotic cells.

    Science.gov (United States)

    Coburn, Phillip S; Gilmore, Michael S

    2003-10-01

    The enterococcal cytolysin, a two-peptide lytic system, is a divergent relative of a large family of toxins and bacteriocins secreted by pathogenic and non-pathogenic Gram-positive bacteria. This family includes the lantibiotics and streptolysin S. The enterococcal cytolysin is of interest because its activities enhance enterococcal virulence in infection models and, in epidemiological studies, it has been associated with patient mortality. The cytolysin is lethal for a broad range of prokaryotic and eukaryotic cells, and this activity requires two non-identical, post-translationally modified peptides. The smaller of the two peptides also plays a role in a quorum-sensing autoinduction of the cytolysin operon. As a trait that is present in particularly virulent strains of Enterococcus faecalis, including strains that are resistant to multiple antibiotics, it serves as a model for testing the value of developing new virulence-targeting therapeutics. Further, because of the interest in small membrane active peptides as therapeutics themselves, studies of the molecular structure/activity relationships for the cytolysin peptides are providing insights into the physical basis for prokaryotic versus eukaryotic cell targeting.

  17. Cholera in Zimbabwe

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

    By the end of December 2008, alarming reports and articles concerning the cholera outbreak in Zimbabwe received plenty of international media coverage. By that time nearly 30000 cases of cholera infections and 1600 cholera deaths had been reported. In the first week of January 2009, a System Dynamic

  18. Catechol Siderophore Transport by Vibrio cholerae

    Science.gov (United States)

    Allred, Benjamin E.; Raymond, Kenneth N.; Payne, Shelley M.

    2015-01-01

    ABSTRACT 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. IMPORTANCE 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

  19. 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.

  20. Mechanisms of cytolysin-induced cell damage -- a role for auto- and paracrine signalling

    DEFF Research Database (Denmark)

    Skals, Marianne Gerberg; Prætorius, Helle

    2013-01-01

    Cytolysins inflict cell damage by forming pores in the plasma membrane. The Na(+) conductivity of these pores results in an ion influx that exceeds the capacity of the Na(+) /K(+) -pump to extrude Na(+) . This net load of intracellular osmolytes results in swelling and eventual lysis of the attac...

  1. Modeling cholera outbreaks

    OpenAIRE

    Dennis L Chao; Longini, Ira M.; Morris, J. Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating mo...

  2. 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.

  3. Cholera outbreaks in India.

    Science.gov (United States)

    Ramamurthy, Thandavarayan; Sharma, Naresh C

    2014-01-01

    Cholera is a global health problem as several thousands of cases and deaths occur each year. The unique epidemiologic attribute of the disease is its propensity to occur as outbreaks that may flare-up into epidemics, if not controlled. The causative bacterial pathogen Vibrio cholerae prevails in the environment and infects humans whenever there is a breakdown in the public health component. The Indian subcontinent is vulnerable to this disease due its vast coastlines with areas of poor sanitation, unsafe drinking water, and overcrowding. Recently, it was shown that climatic conditions also play a major role in the persistence and spread of cholera. Constant change in the biotypes and serotypes of V. cholerae are also important aspects that changes virulence and survival of the pathogen. Such continuous changes increase the infection ability of the pathogen affecting the susceptible population including the children. The short-term carrier status of V. cholerae has been studied well at community level and this facet significantly contributes to the recurrence of cholera. Several molecular tools recognized altering clonality of V. cholerae in relation with the advent of a serogroup or serotype. Rapid identification systems were formulated for the timely detection of the pathogen so as to identify and control the outbreak and institute proper treatment of the patients. The antimicrobials used in the past are no longer useful in the treatment of cholera as V. cholerae has acquired several mechanisms for multiple antimicrobial resistance. This upsurge in antimicrobial resistance directly influences the management of the disease. This chapter provides an overview of cholera prevalence in India, possible sources of infection, and molecular epidemiology along with antimicrobial resistance of V. cholerae.

  4. Enterococcal cytolysin: a novel two component peptide system that serves as a bacterial defense against eukaryotic and prokaryotic cells.

    Science.gov (United States)

    Cox, Christopher R; Coburn, Phillip S; Gilmore, Michael S

    2005-02-01

    The cytolysin is a novel, two-peptide lytic toxin produced by some strains of Enterococcus faecalis. It is toxic in animal models of enterococcal infection, and associated with acutely terminal outcome in human infection. The cytolysin exerts activity against a broad spectrum of cell types including a wide range of gram positive bacteria, eukaryotic cells such as human, bovine and horse erythrocytes, retinal cells, polymorphonuclear leukocytes, and human intestinal epithelial cells. The cytolysin likely originated as a bacteriocin involved with niche control in the complex microbial ecologies associated with eukaryotic hosts. However, additional anti-eukaryotic activities may have been selected for as enterococci adapted to eukaryotic cell predation in water or soil ecologies. Cytolytic activity requires two unique peptides that possess modifications characteristic of the lantibiotic bacteriocins, and these peptides are broadly similar in size to most cationic eukaryotic defensins. Expression of the cytolysin is tightly controlled by a novel mode of gene regulation in which the smaller peptide signals high-level expression of the cytolysin gene cluster. This complex regulation of cytolysin expression may have evolved to balance defense against eukaryotic predators with stealth.

  5. Vibrio cholerae in an Historically Cholera-Free Country.

    Science.gov (United States)

    Haley, Bradd J; Chen, Arlene; Grim, Christopher J; Clark, Philip; Diaz, Celia Municio; Taviani, Elisa; Hasan, Nur A; Sancomb, Elizabeth; Elnemr, Wessam Mahmoud; Islam, Muhammad A; Huq, Anwar; Colwell, Rita R; Benediktsdóttir, Eva

    2012-08-01

    We report the autochthonous existence of Vibrio cholerae in coastal waters of Iceland, a geothermally active country where cholera is absent and has never been reported. Seawater, mussel, and macroalgae samples were collected close to and distant from sites where geothermal activity causes a significant increase in water temperature during low tides. V. cholerae was detected only at geothermal-influenced sites during low-tides. None of the V. cholerae isolates encoded cholera toxin (ctxAB) and all were non-O1/non-O139 serogroups. However, all isolates encoded other virulence factors that are associated with cholera as well as extra-intestinal V. cholerae infections. The virulence factors were functional at temperatures of coastal waters of Iceland, suggesting an ecological role. It is noteworthy that V. cholerae was isolated from samples collected at sites distant from anthropogenic influence, supporting the conclusion that V. cholerae is autochthonous to the aquatic environment of Iceland.

  6. Radiolabelling of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.G.; Neves, Nicoli M.J. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L. [Ouro Preto Univ., MG (Brazil). Escola de Farmacia. Lab. de Fisiologia e Bioquimica de Microorganismos; Lima, M.E. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Bioquimica e Imunologia; Nicoli, J.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Microbiologia

    1999-11-01

    Binding of cholera toxin to ganglioside receptors of enterocyte microvilli catalyzes the activation of adenylate cyclase causing a rise in cAMP which final result is a copious diarrhea. Saccharomyces boulardii, a nonpathogenic yeast has been used to prevent diarrhea. Although the antidiarrheic properties of S. boulardii are widely recognized, this yeast has been used on empirical basis, and the mechanism of this protective effect is unknown. The addition of cholera toxin to S. boulardii induces the raising of cAMP that triggers the activation of neutral trehalase. This suggests that toxin specifically binding to cells, is internalized and active the protein phosphorylation cascade. Our objective is labeling the cholera toxin to verify the presence of binding sites on yeast cell surfaces for the cholera toxin. Cholera toxin was radiolabelled with Na {sup 125} I by a chloramine-T method modified from Cuatrecasas and Griffiths et alii. The {sup 125} I-Cholera toxin showed a specific radioactivity at about 1000 cpm/fmol toxin. Biological activity of labeled cholera toxin measured by trehalase activation was similar to the native toxin. (author) 5 refs., 3 figs.; e-mail: nevesmj at urano.cdtn.br

  7. Characterization of Anthrolysin O, the Bacillus anthracis Cholesterol-Dependent Cytolysin

    OpenAIRE

    Shannon, Jeffrey G; Ross, Cana L.; Koehler, Theresa M.; Rest, Richard F

    2003-01-01

    We characterized the expression of a putative toxin of Bacillus anthracis, a member of the cholesterol-dependent cytolysin (CDC) family, which includes listeriolysin O, perfringolysin O, and streptolysin O. We named this cytotoxin anthrolysin O (ALO). Although B. anthracis expresses minimal hemolytic activity in clinical settings, we show that Sterne strain 7702 expresses hemolytic activity when grown in brain heart infusion broth or in other rich bacteriologic media, but it secretes barely d...

  8. Cholera in Azov area

    OpenAIRE

    O. N. Domashenko; T. A. Belomerya; N. V. Martynova; G. N. Daragan; Demkovich, O.O.; U. V. Malakhova; G. I. Zemlyanskaya; Popova, D.M.

    2015-01-01

    The purpose of research is analysis of clinical course and treatment results of patients with cholera in the Azov area. Materials and methods. During the period from 29.05.2011 to 19.08.2011 33 cases of cholera (32 adults and 1 child) and 25 vibrio carriers (22 adults and 3 children), which were caused by toxigenic strains of Vibrio cholera El Tor serogroup O1 Ogawa. Results. Likely factors of disease transmission in Mariupol are sea and river water, and the fish that were caught in the water...

  9. Bacterial cytolysin during meningitis disrupts the regulation of glutamate in the brain, leading to synaptic damage.

    Directory of Open Access Journals (Sweden)

    Carolin Wippel

    Full Text Available Streptococcus pneumoniae (pneumococcal meningitis is a common bacterial infection of the brain. The cholesterol-dependent cytolysin pneumolysin represents a key factor, determining the neuropathogenic potential of the pneumococci. Here, we demonstrate selective synaptic loss within the superficial layers of the frontal neocortex of post-mortem brain samples from individuals with pneumococcal meningitis. A similar effect was observed in mice with pneumococcal meningitis only when the bacteria expressed the pore-forming cholesterol-dependent cytolysin pneumolysin. Exposure of acute mouse brain slices to only pore-competent pneumolysin at disease-relevant, non-lytic concentrations caused permanent dendritic swelling, dendritic spine elimination and synaptic loss. The NMDA glutamate receptor antagonists MK801 and D-AP5 reduced this pathology. Pneumolysin increased glutamate levels within the mouse brain slices. In mouse astrocytes, pneumolysin initiated the release of glutamate in a calcium-dependent manner. We propose that pneumolysin plays a significant synapto- and dendritotoxic role in pneumococcal meningitis by initiating glutamate release from astrocytes, leading to subsequent glutamate-dependent synaptic damage. We outline for the first time the occurrence of synaptic pathology in pneumococcal meningitis and demonstrate that a bacterial cytolysin can dysregulate the control of glutamate in the brain, inducing excitotoxic damage.

  10. Cholera outbreaks in Africa.

    Science.gov (United States)

    Mengel, Martin A; Delrieu, Isabelle; Heyerdahl, Leonard; Gessner, Bradford D

    2014-01-01

    During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with

  11. Cholera Fact Sheet

    Science.gov (United States)

    ... facilities (chlorination) interventions at the household level (water filtration, chemical or solar disinfection of water, safe water ... spread of cholera and contributes to increasing antimicrobial resistance. Rapid access to treatment is essential during a ...

  12. 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.

  13. Intradermal immunization in the ear with cholera toxin and its non-toxic β subunit promotes efficient Th1 and Th17 differentiation dependent on migrating DCs.

    Science.gov (United States)

    Meza-Sánchez, David; Pérez-Montesinos, Gibrán; Sánchez-García, Javier; Moreno, José; Bonifaz, Laura C

    2011-10-01

    The nature of CD4(+) T-cell responses after skin immunization and the role of migrating DCs in the presence of adjuvants in the elicited response are interesting issues to be investigated. Here, we evaluated the priming of CD4(+) T cells following ear immunization with low doses of model antigens in combination with either cholera toxin (CT) or the non-toxic β CT subunit (CTB) as an adjuvant. Following immunization with CT, we found efficient antigen presentation that is reflected in the production of IFN-γ and IL-17 by CD4(+) T cells over IL-4 or IL-5 production. The CTB-induced activation of DCs in the ear occurred without visible inflammation, which reflects a similar type of CD4(+) T-cell differentiation. In both cases, the elicited response was dependent on the presence of migrating skin cells. Remarkably, immunization with CT or with CTB led to the induction of a delayed-type hypersensitivity (DTH) response in the ear. The DTH response that was induced by CT immunization was dependent on IL-17 and partially dependent on IFN-γ activity. These results indicate that both CT and CTB induce an efficient CD4(+) T-cell response to a co-administered antigen following ear immunization that is dependent on migrating DCs.

  14. 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.

  15. Pharmacological effects of two cytolysins isolated from the sea anemone Stichodactyla helianthus

    Indian Academy of Sciences (India)

    T García; D Martinez; A Palmero; C Soto; M Tejuca; F Pazos; R Menéndez; C Alvarez; A Garateix

    2009-12-01

    Sticholysins I and II (St I/II) are cytolysins purified from the sea anemone Stichodactyla helianthus. In this study, we show their pharmacological action on guinea-pig and snail models in native and pH-denatured conditions in order to correlate the pharmacological findings with the pore-forming activity of both isoforms. In guinea-pig erythrocytes ( = 3), St II possessed higher haemolytic activity in comparison with St I and this activity was lost at an alkaline pH. In molluscan central neurons ( = 30), they irreversibly decreased the amplitude of the cholinergic response; St I (EC50 0.6 molL–1) was more potent than St II (EC50 > 6.6 molL–1) and they both increased the duration of the action potential; these effects were absent at an alkaline pH. In guinea-pig isolated atrium ( = 25), both increased the amplitude of the contraction force, but St II was more potent than St I (EC50 0.03 molL–1 and 0.3 molL–1, respectively) and this effect persisted at an alkaline pH. In summary, both cytolysins have neuroactive and cardioactive properties. The main mechanism in molluscan neurons seems to be associated with the cytolytic activity of these molecules, whereas in guinea-pig atrium, the existence of an additional pharmacological mechanism might be contributing to the observed effect.

  16. Cholera Illness and Symptoms

    Science.gov (United States)

    ... are typically no long term consequences. Persons with cholera do not become carriers of the disease after they recover, but can be reinfected if ... Diseases (NCEZID) Division of Foodborne, Waterborne, and Environmental Diseases (DFWED) ... of Health & Human Services HHS/Open USA.gov Top

  17. Characterization, purification and phylogenetic analysis of a cytolysin from the sea anemone Heteractis magnifica of the Indian Ocean

    Directory of Open Access Journals (Sweden)

    S Karthikayalu

    2010-01-01

    Full Text Available It is well established that sea anemones comprise a rich source of cytolytic toxins. The present study reports the isolation and characterization of a cytolysin obtained from the sea anemone Heteractis magnifica collected in the Andaman Islands of the Indian Ocean. The crude extract was screened for hemolytic activity by a blood agar plate method and a 6-mm zone of clearance was observed after incubation. The hemolytic property of the crude extract, tested by the microtiter plate method, revealed positive results at concentrations as low as 120 ng/mL. Furthermore, it was favored by alkaline pH and was stable up to 60°C. On the other hand, the hemolytic effect was abolished by the addition of human serum. Purification steps involved ammonium sulfate precipitation and subsequent desalting by dialysis, followed by anion- and cation-exchange chromatographies. The purified fractions displayed the presence of a 19-kDa cytolysin when analyzed by SDS-PAGE. The conserved region of the cytolysin (with 303 bp was amplified by RT-PCR and was sequenced. The sequence showed maximum homology (97% with the already reported cytolysins from other sea anemone species.

  18. Survival of Vibrio cholerae in nutrient-poor environments is associated with a novel "persister" phenotype.

    Directory of Open Access Journals (Sweden)

    Mohamma Jubair

    Full Text Available In response to antibiotic and/or environmental stress, some species of bacteria shift to a "persister" phenotype. Although toxigenic Vibrio cholerae, responsible for the disease cholera, can be found in nutrient-poor aquatic environments in endemic areas, the underlying mechanism(s by which culturable cells persist in these environmental reservoirs is largely unknown. Here we report that introduction of V. cholerae into a nutrient-poor filter sterilized lake water (FSLW microcosm promoted a shift to what we have defined as a "persister" phenotype (PP which was culturable for >700 days. Direct transfer of PP of V. cholerae from original microcosms to freshly prepared FSLW resulted in the same pattern of persistence seen in the original microcosms. Scanning electron microscopy of cells persisting for over 700 days demonstrated cell morphologies that were very small in size, with a high degree of aggregation associated with flagella emanating from all aspects of the cell. V. cholerae PP cells reverted to a typical V. cholerae morphology when transferred to nutrient-rich L- broth. Cell-free supernatants obtained from microcosms at 24 hours, 180 days, and 700 days all showed >2-fold increase in CAI-1 signaling molecules, consistent with quorum sensing activity, as has been described for Pseudomonas aeruginosa persister cells. Chitin and phosphate promoted cell growth. Our data suggest that nutrient stress can select a V. cholerae persister phenotype in environmental reservoirs, with these strains then seeding subsequent cholera epidemics in response to chitin and phosphate availability.

  19. Crystal structure of an invertebrate cytolysin pore reveals unique properties and mechanism of assembly

    Science.gov (United States)

    Podobnik, Marjetka; Savory, Peter; Rojko, Nejc; Kisovec, Matic; Wood, Neil; Hambley, Richard; Pugh, Jonathan; Wallace, E. Jayne; McNeill, Luke; Bruce, Mark; Liko, Idlir; Allison, Timothy M.; Mehmood, Shahid; Yilmaz, Neval; Kobayashi, Toshihide; Gilbert, Robert J. C.; Robinson, Carol V.; Jayasinghe, Lakmal; Anderluh, Gregor

    2016-05-01

    The invertebrate cytolysin lysenin is a member of the aerolysin family of pore-forming toxins that includes many representatives from pathogenic bacteria. Here we report the crystal structure of the lysenin pore and provide insights into its assembly mechanism. The lysenin pore is assembled from nine monomers via dramatic reorganization of almost half of the monomeric subunit structure leading to a β-barrel pore ~10 nm long and 1.6-2.5 nm wide. The lysenin pore is devoid of additional luminal compartments as commonly found in other toxin pores. Mutagenic analysis and atomic force microscopy imaging, together with these structural insights, suggest a mechanism for pore assembly for lysenin. These insights are relevant to the understanding of pore formation by other aerolysin-like pore-forming toxins, which often represent crucial virulence factors in bacteria.

  20. Perfringolysin O structure and mechanism of pore formation as a paradigm for cholesterol-dependent cytolysins.

    Science.gov (United States)

    Johnson, Benjamin B; Heuck, Alejandro P

    2014-01-01

    Cholesterol-dependent cytolysins (CDCs) constitute a family of pore forming toxins secreted by Gram-positive bacteria. These toxins form transmembrane pores by inserting a large β-barrel into cholesterol-containing membrane bilayers. Binding of water-soluble CDCs to the membrane triggers the formation of oligomers containing 35-50 monomers. The coordinated insertion of more than seventy β-hairpins into the membrane requires multiple structural conformational changes. Perfringolysin O (PFO), secreted by Clostridium perfringens, has become the prototype for the CDCs. In this chapter, we will describe current knowledge on the mechanism of PFO cytolysis, with special focus on cholesterol recognition, oligomerization, and the conformational changes involved in pore formation.

  1. Stepwise visualization of membrane pore formation by suilysin, a bacterial cholesterol-dependent cytolysin.

    Science.gov (United States)

    Leung, Carl; Dudkina, Natalya V; Lukoyanova, Natalya; Hodel, Adrian W; Farabella, Irene; Pandurangan, Arun P; Jahan, Nasrin; Pires Damaso, Mafalda; Osmanović, Dino; Reboul, Cyril F; Dunstone, Michelle A; Andrew, Peter W; Lonnen, Rana; Topf, Maya; Saibil, Helen R; Hoogenboom, Bart W

    2014-12-02

    Membrane attack complex/perforin/cholesterol-dependent cytolysin (MACPF/CDC) proteins constitute a major superfamily of pore-forming proteins that act as bacterial virulence factors and effectors in immune defence. Upon binding to the membrane, they convert from the soluble monomeric form to oligomeric, membrane-inserted pores. Using real-time atomic force microscopy (AFM), electron microscopy (EM), and atomic structure fitting, we have mapped the structure and assembly pathways of a bacterial CDC in unprecedented detail and accuracy, focussing on suilysin from Streptococcus suis. We show that suilysin assembly is a noncooperative process that is terminated before the protein inserts into the membrane. The resulting ring-shaped pores and kinetically trapped arc-shaped assemblies are all seen to perforate the membrane, as also visible by the ejection of its lipids. Membrane insertion requires a concerted conformational change of the monomeric subunits, with a marked expansion in pore diameter due to large changes in subunit structure and packing.

  2. Environmental Monitoring of Endemic Cholera

    Science.gov (United States)

    ElNemr, W.; Jutla, A. S.; Constantin de Magny, G.; Hasan, N. A.; Islam, M.; Sack, R.; Huq, A.; Hashem, F.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat. Since Vibrio cholerae, the causative agent of the disease, is autochthonous to riverine, estuarine, and coastal waters, it is unlikely the bacteria can be eradicated from its natural habitat. Prediction of disease, in conjunction with preventive vaccination can reduce the prevalence rate of a disease. Understanding the influence of environmental parameters on growth and proliferation of bacteria is an essential first step in developing prediction methods for outbreaks. Large scale geophysical variables, such as SST and coastal chlorophyll, are often associated with conditions favoring growth of V. cholerae. However, local environmental factors, meaning biological activity in ponds from where the bulk of populations in endemic regions derive water for daily usage, are either neglected or oversimplified. Using data collected from several sites in two geographically distinct locations in South Asia, we have identified critical local environmental factors associated with cholera outbreak. Of 18 environmental variables monitored for water sources in Mathbaria (a coastal site near the Bay of Bengal) and Bakergonj (an inland site) of Bangladesh, water depth and chlorophyll were found to be important factors associated with initiation of cholera outbreaks. Cholera in coastal regions appears to be related to intrusion. However, monsoonal flooding creates conditions for cholera epidemics in inland regions. This may be one of the first attempts to relate in-situ environmental observations with cholera. We anticipate that it will be useful for further development of prediction models in the resource constrained regions.

  3. Identification of a cross-reactive HLA-DRB1*0301-restricted CD4 T cell response directed against cholesterol-binding cytolysins from two different pathogens.

    Science.gov (United States)

    Paschen, Annette; Song, Mingxia; Schenk, Simone; Janda, Jozef; Nguyen, Xuan Duc; Osen, Wolfram; Schadendorf, Dirk; Geginat, Gernot

    2006-07-01

    Cholesterol-binding cytolysins constitute an evolutionarily conserved family of pore-forming proteins expressed by different gram-positive pathogens. Listeriolysin O, one well-characterized member of the cytolysin family, is also known to induce specific CD4 and CD8 T cell responses upon infection of mice with Listeria monocytogenes. Here we describe an HLA-DRB1*0301-restricted listeriolysin O-derived T cell epitope that is conserved among several members of the cytolysin family. An HLA-DRB1*0301-restricted CD4+ T cell line, established from spleen lymphocytes of L. monocytogenes-infected HLA-DRB1*0301-transgenic mice, cross-reacted with a homologous peptide from perfringolysin O, a cytolysin expressed by Clostridium perfringens. Ex vivo analysis of infected mice revealed an even broader cross-reaction of T cells with homologous peptides derived from perfringolysin O, streptolysin O, and cereolysin O. Interestingly, a cross-reactive memory CD4+ T cell response against the homologous peptides derived from listeriolysin O and perfringolysin O could also be detected in the blood from healthy HLA-DRB1*0301+ human donors. Remarkably, this response was even present in donors who did not exhibit a memory T cell reactivity against a second, non-conserved HLA-DRB1*0301-restricted LLO-derived CD4 T cell epitope, suggesting that cytolysin-producing bacteria other than L. monocytogenes can stimulate a cross-reactive cytolysin-specific immunity.

  4. Transcription and translation products of the cytolysin gene psm-mec on the mobile genetic element SCCmec regulate Staphylococcus aureus virulence.

    Science.gov (United States)

    Kaito, Chikara; Saito, Yuki; Nagano, Gentaro; Ikuo, Mariko; Omae, Yosuke; Hanada, Yuichi; Han, Xiao; Kuwahara-Arai, Kyoko; Hishinuma, Tomomi; Baba, Tadashi; Ito, Teruyo; Hiramatsu, Keiichi; Sekimizu, Kazuhisa

    2011-02-03

    The F region downstream of the mecI gene in the SCCmec element in hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) contains two bidirectionally overlapping open reading frames (ORFs), the fudoh ORF and the psm-mec ORF. The psm-mec ORF encodes a cytolysin, phenol-soluble modulin (PSM)-mec. Transformation of the F region into the Newman strain, which is a methicillin-sensitive S. aureus (MSSA) strain, or into the MW2 (USA400) and FRP3757 (USA300) strains, which are community-acquired MRSA (CA-MRSA) strains that lack the F region, attenuated their virulence in a mouse systemic infection model. Introducing the F region to these strains suppressed colony-spreading activity and PSMα production, and promoted biofilm formation. By producing mutations into the psm-mec ORF, we revealed that (i) both the transcription and translation products of the psm-mec ORF suppressed colony-spreading activity and promoted biofilm formation; and (ii) the transcription product of the psm-mec ORF, but not its translation product, decreased PSMα production. These findings suggest that both the psm-mec transcript, acting as a regulatory RNA, and the PSM-mec protein encoded by the gene on the mobile genetic element SCCmec regulate the virulence of Staphylococcus aureus.

  5. Transcription and translation products of the cytolysin gene psm-mec on the mobile genetic element SCCmec regulate Staphylococcus aureus virulence.

    Directory of Open Access Journals (Sweden)

    Chikara Kaito

    Full Text Available The F region downstream of the mecI gene in the SCCmec element in hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA contains two bidirectionally overlapping open reading frames (ORFs, the fudoh ORF and the psm-mec ORF. The psm-mec ORF encodes a cytolysin, phenol-soluble modulin (PSM-mec. Transformation of the F region into the Newman strain, which is a methicillin-sensitive S. aureus (MSSA strain, or into the MW2 (USA400 and FRP3757 (USA300 strains, which are community-acquired MRSA (CA-MRSA strains that lack the F region, attenuated their virulence in a mouse systemic infection model. Introducing the F region to these strains suppressed colony-spreading activity and PSMα production, and promoted biofilm formation. By producing mutations into the psm-mec ORF, we revealed that (i both the transcription and translation products of the psm-mec ORF suppressed colony-spreading activity and promoted biofilm formation; and (ii the transcription product of the psm-mec ORF, but not its translation product, decreased PSMα production. These findings suggest that both the psm-mec transcript, acting as a regulatory RNA, and the PSM-mec protein encoded by the gene on the mobile genetic element SCCmec regulate the virulence of Staphylococcus aureus.

  6. 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...

  7. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  8. Randomized Controlled Trial of Hospital-Based Hygiene and Water Treatment Intervention (CHoBI7) to Reduce Cholera

    Science.gov (United States)

    Monira, Shirajum; Sack, David A.; Rashid, Mahamud-ur; Saif-Ur-Rahman, K.M.; Mahmud, Toslim; Rahman, Zillur; Mustafiz, Munshi; Bhuyian, Sazzadul Islam; Winch, Peter J.; Leontsini, Elli; Perin, Jamie; Begum, Farzana; Zohura, Fatema; Biswas, Shwapon; Parvin, Tahmina; Zhang, Xiaotong; Jung, Danielle; Sack, R. Bradley; Alam, Munirul

    2016-01-01

    The risk for cholera infection is >100 times higher for household contacts of cholera patients during the week after the index patient seeks hospital care than it is for the general population. To initiate a standard of care for this high-risk population, we developed Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which promotes hand washing with soap and treatment of water. To test CHoBI7, we conducted a randomized controlled trial among 219 intervention household contacts of 82 cholera patients and 220 control contacts of 83 cholera patients in Dhaka, Bangladesh, during 2013–2014. Intervention contacts had significantly fewer symptomatic Vibrio cholerae infections than did control contacts and 47% fewer overall V. cholerae infections. Intervention households had no stored drinking water with V. cholerae and 14 times higher odds of hand washing with soap at key events during structured observation on surveillance days 5, 6, or 7. CHoBI7 presents a promising approach for controlling cholera among highly susceptible household contacts of cholera patients. PMID:26811968

  9. Role of Ectoine in Vibrio cholerae Osmoadaptation

    OpenAIRE

    Pflughoeft, Kathryn J.; Kierek, Katharine; Paula I Watnick

    2003-01-01

    Vibrio cholerae is both an intestinal pathogen and a microbe in the estuarine community. To persist in the estuarine environment, V. cholerae must adjust to changes in ionic composition and osmolarity. These changes in the aquatic environment have been correlated with cholera epidemics. In this work, we study the response of V. cholerae to increases in environmental osmolarity. Optimal growth of V. cholerae in minimal medium requires supplementation with 200 mM NaCl and KCl. However, when the...

  10. 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.

  11. Purification of a 19-kDa pore-forming cytolysin from the sea anemone Heteractis magnifica

    Directory of Open Access Journals (Sweden)

    S Karthikayalu

    2010-01-01

    Full Text Available Pore-forming cytolysins of 19 kDa from sea anemones present a remarkable cytolytic property. In the present work, a purified 19-kDa cytolysin was obtained from the sea anemone Heteractis magnifica. The purification steps involved ammonium sulfate precipitation and subsequently desalting by dialysis against 10 mM sodium phosphate buffer (pH 7.4, followed by anion exchange chromatography in DEAE-Sepharose® column (GE Healthcare, Sweden and gel filtration chromatography using Sephadex® G-50 matrix (GE Healthcare, Sweden. The active fractions from the gel filtration chromatography were pooled and rechromatographed in the same column. The final active fraction showed a prominent protein band of molecular mass of 19 kDa when analyzed by SDS-PAGE.

  12. Nonredundant Roles of Iron Acquisition Systems in Vibrio cholerae.

    Science.gov (United States)

    Peng, Eric D; Wyckoff, Elizabeth E; Mey, Alexandra R; Fisher, Carolyn R; Payne, Shelley M

    2015-12-07

    Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, thrives in both marine environments and the human host. To do so, it must encode the tools necessary to acquire essential nutrients, including iron, under these vastly different conditions. A number of V. cholerae iron acquisition systems have been identified; however, the precise role of each system is not fully understood. To test the roles of individual systems, we generated a series of mutants in which only one of the four systems that support iron acquisition on unsupplemented LB agar, Feo, Fbp, Vct, and Vib, remains functional. Analysis of these mutants under different growth conditions showed that these systems are not redundant. The strain carrying only the ferrous iron transporter Feo grew well at acidic, but not alkaline, pH, whereas the ferric iron transporter Fbp promoted better growth at alkaline than at acidic pH. A strain defective in all four systems (null mutant) had a severe growth defect under aerobic conditions but accumulated iron and grew as well as the wild type in the absence of oxygen, suggesting the presence of an additional, unidentified iron transporter in V. cholerae. In support of this, the null mutant was only moderately attenuated in an infant mouse model of infection. While the null mutant used heme as an iron source in vitro, we demonstrate that heme is not available to V. cholerae in the infant mouse intestine.

  13. Expression of accessory colonization factor subunit A (ACFA) of Vibrio cholerae and ACFA fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum).

    Science.gov (United States)

    Sharma, Manoj Kumar; Jani, Dewal; Thungapathra, M; Gautam, J K; Meena, L S; Singh, Yogendra; Ghosh, Amit; Tyagi, Akhilesh Kumar; Sharma, Arun Kumar

    2008-05-20

    In earlier study from our group, cholera toxin B subunit had been expressed in tomato for developing a plant-based vaccine against cholera. In the present investigation, gene for accessory colonization factor (acf) subunit A, earlier reported to be essential for efficient colonization in the intestine, has been expressed in Escherichia coli as well as tomato plants. Gene encoding for a chimeric protein having a fusion of cholera toxin B subunit and accessory colonization factor A was also expressed in tomato to generate more potent combinatorial antigen. CaMV35S promoter with a duplicated enhancer sequence was used for expression of these genes in tomato. Integration of transgenes into tomato genome was confirmed by PCR and Southern hybridization. Expression of the genes was confirmed at transcript and protein levels. Accessory colonization factor A and cholera toxin B subunit fused to this protein accumulated up to 0.25% and 0.08% of total soluble protein, respectively, in the fruits of transgenic plants. Whereas protein purified from E. coli, in combination with cholera toxin B subunit can be used for development of conventional subunit vaccine, tomato fruits expressing these proteins can be used together with tomato plants expressing cholera toxin B subunit for development of oral vaccine against cholera.

  14. Cytokine production in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis: dynamics of mRNA expression for interleukin-10, interleukin-12, cytolysin, tumor necrosis factor alpha and tumor necrosis factor beta

    DEFF Research Database (Denmark)

    Issazadeh-Navikas, Shohreh; Ljungdahl, A; Höjeberg, B

    1995-01-01

    in cryosections of spinal cords using in situ hybridization technique with synthetic oligonucleotide probes. Three stages of cytokine mRNA expression could be distinguished: (i) interleukin (IL)-12, tumor necrosis factor (TNF)-beta (= lymphotoxin-alpha) and cytolysin appeared early and before onset of clinical...... signs of EAE; (ii) TNF-alpha peaked at height of clinical signs of EAE; (iii) IL-10 appeared increasingly at and after clinical recovery. The early expression of IL-12 prior to the expression of interferon-gamma (IFN-gamma) mRNA shown previously is consistent with a role of IL-12 in promoting...... proliferation and activation of T helper 1 (Th1) type cells producing IFN-gamma. The TNF-beta mRNA expression prior to onset of clinical signs favours a role for this cytokine in disease initiation. A pathogenic effector role of TNF-alpha was suggested from these observations that TNF-alpha mRNA expression...

  15. Chromosome Segregation in Vibrio cholerae

    OpenAIRE

    Ramachandran, R.; Jha, J.; Chattoraj, DK

    2014-01-01

    The study of chromosome segregation is currently one of the most exciting research frontiers in cell biology. In this review, we discuss our current knowledge of the chromosome segregation process in Vibrio cholerae, based primarily on findings from fluorescence microscopy experiments. This bacterium is of special interest because of its eukaryotic feature of having a divided genome, a feature shared with 10% of known bacteria. We also discuss how the segregation mechanisms of V. cholerae com...

  16. Non-O1 Vibrio cholerae in Thailand: homology with cloned cholera toxin genes.

    OpenAIRE

    Hanchalay, S; Seriwatana, J; Echeverria, P.; Holmgren, J.; Tirapat, C.; Moseley, S L; Taylor, D N

    1985-01-01

    We examined 281 non-O1 Vibrio cholerae isolates from Thailand for homology with genes coding for cholera toxin. Five isolates from environmental sources were homologous with the cholera toxin gene probe and produced both the A and B subunits of cholera toxin.

  17. A new model for pore formation by cholesterol-dependent cytolysins.

    Directory of Open Access Journals (Sweden)

    Cyril F Reboul

    2014-08-01

    Full Text Available Cholesterol Dependent Cytolysins (CDCs are important bacterial virulence factors that form large (200-300 Å membrane embedded pores in target cells. Currently, insights from X-ray crystallography, biophysical and single particle cryo-Electron Microscopy (cryo-EM experiments suggest that soluble monomers first interact with the membrane surface via a C-terminal Immunoglobulin-like domain (Ig; Domain 4. Membrane bound oligomers then assemble into a prepore oligomeric form, following which the prepore assembly collapses towards the membrane surface, with concomitant release and insertion of the membrane spanning subunits. During this rearrangement it is proposed that Domain 2, a region comprising three β-strands that links the pore forming region (Domains 1 and 3 and the Ig domain, must undergo a significant yet currently undetermined, conformational change. Here we address this problem through a systematic molecular modeling and structural bioinformatics approach. Our work shows that simple rigid body rotations may account for the observed collapse of the prepore towards the membrane surface. Support for this idea comes from analysis of published cryo-EM maps of the pneumolysin pore, available crystal structures and molecular dynamics simulations. The latter data in particular reveal that Domains 1, 2 and 4 are able to undergo significant rotational movements with respect to each other. Together, our data provide new and testable insights into the mechanism of pore formation by CDCs.

  18. A non-classical assembly pathway of Escherichia coli pore-forming toxin cytolysin A.

    Science.gov (United States)

    Fahie, Monifa; Romano, Fabian B; Chisholm, Christina; Heuck, Alejandro P; Zbinden, Mark; Chen, Min

    2013-10-25

    Cytolysin A (ClyA) is an α-pore forming toxin from pathogenic Escherichia coli (E. coli) and Salmonella enterica. Here, we report that E. coli ClyA assembles into an oligomeric structure in solution in the absence of either bilayer membranes or detergents at physiological temperature. These oligomers can rearrange to create transmembrane pores when in contact with detergents or biological membranes. Intrinsic fluorescence measurements revealed that oligomers adopted an intermediate state found during the transition between monomer and transmembrane pore. These results indicate that the water-soluble oligomer represents a prepore intermediate state. Furthermore, we show that ClyA does not form transmembrane pores on E. coli lipid membranes. Because ClyA is delivered to the target host cell in an oligomeric conformation within outer membrane vesicles (OMVs), our findings suggest ClyA forms a prepore oligomeric structure independently of the lipid membrane within the OMV. The proposed model for ClyA represents a non-classical pathway to attack eukaryotic host cells.

  19. A new model for pore formation by cholesterol-dependent cytolysins.

    Science.gov (United States)

    Reboul, Cyril F; Whisstock, James C; Dunstone, Michelle A

    2014-08-01

    Cholesterol Dependent Cytolysins (CDCs) are important bacterial virulence factors that form large (200-300 Å) membrane embedded pores in target cells. Currently, insights from X-ray crystallography, biophysical and single particle cryo-Electron Microscopy (cryo-EM) experiments suggest that soluble monomers first interact with the membrane surface via a C-terminal Immunoglobulin-like domain (Ig; Domain 4). Membrane bound oligomers then assemble into a prepore oligomeric form, following which the prepore assembly collapses towards the membrane surface, with concomitant release and insertion of the membrane spanning subunits. During this rearrangement it is proposed that Domain 2, a region comprising three β-strands that links the pore forming region (Domains 1 and 3) and the Ig domain, must undergo a significant yet currently undetermined, conformational change. Here we address this problem through a systematic molecular modeling and structural bioinformatics approach. Our work shows that simple rigid body rotations may account for the observed collapse of the prepore towards the membrane surface. Support for this idea comes from analysis of published cryo-EM maps of the pneumolysin pore, available crystal structures and molecular dynamics simulations. The latter data in particular reveal that Domains 1, 2 and 4 are able to undergo significant rotational movements with respect to each other. Together, our data provide new and testable insights into the mechanism of pore formation by CDCs.

  20. Comparison of Vibrio cholerae O139 with V. cholerae O1 classical and El Tor biotypes.

    OpenAIRE

    Calia, K E; Murtagh, M.; Ferraro, M J; Calderwood, S B

    1994-01-01

    Vibrio cholerae O139 is a recently identified non-O1 V. cholerae strain responsible for outbreaks of epidemic cholera in India, Bangladesh, and Thailand in the past 2 years. Other workers have demonstrated the presence of the cholera toxin genetic element in V. cholerae O139, unlike the situation for other non-O1 V. cholerae strains. We sought to compare further this strain with strains of V. cholerae O1, classical and El Tor biotypes, by classic microbiologic methods, Southern blot analysis ...

  1. Improved purification process for cholera toxin and its application to the quantification of residual toxin in cholera vaccines.

    Science.gov (United States)

    Jang, Hyun; Kim, Hyo Seung; Kim, Jeong Ah; Seo, Jin Ho; Carbis, Rodney

    2009-01-01

    A simplified method for the purification of cholera toxin was developed. The 569B strain of Vibrio cholerae, a recognized hyper-producer of cholera toxin, was propagated in a bioreactor under conditions that promote the production of the toxin. The toxin was separated from the bacterial cells using 0.2-microm crossflow microfiltration, the clarified toxin was passed through the membrane into the permeate, and the bacterial cells were retained in the retentate. The 0.2-microm permeate was then concentrated 3-fold and diafiltered against 10 mM phosphate buffer, pH 7.6, using 30-kDa crossflow ultrafiltration. The concentrated toxin was loaded onto a cation exchange column, the toxin was bound to the column, and most of the impurities were passed unimpeded through the column. The toxin was eluted with a salt gradient of phosphate buffer, pH7.0, containing 1.0M NaCl. The peak containing the toxin was assayed for cholera toxin and protein and the purity was determined to be 92%. The toxin peak had a low endotoxin level of 3.1 EU/microg of toxin. The purified toxin was used to prepare antiserum against whole toxin, which was used in a G(M1) ganglioside-binding ELISA to determine residual levels of toxin in an oral inactivated whole-cell cholera vaccine. The G(M1) ganglioside-binding ELISA was shown to be very sensitive and capable of detecting as little as 1 ng/ml of cholera toxin.

  2. Characterization of Vibrio cholerae Strains Isolated from the Nigerian Cholera Outbreak in 2010.

    Science.gov (United States)

    Dupke, Susann; Akinsinde, Kehinde A; Grunow, Roland; Iwalokun, Bamidele A; Olukoya, Daniel K; Oluwadun, Afolabi; Velavan, Thirumalaisamy P; Jacob, Daniela

    2016-10-01

    We examined clinical samples from Nigerian patients with acute watery diarrhea for Vibrio cholerae during the 2010 cholera outbreak. A total of 109 suspected isolates were characterized, but only 57 V. cholerae strains could be confirmed using multiplex real-time PCR as well as rpoB sequencing and typed as V. cholerae O:1 Ogawa biotype El Tor. This finding highlighted the need for accurate diagnosis of cholera in epidemic countries to implement life-saving interventions.

  3. Fish as Hosts of Vibrio cholerae

    Science.gov (United States)

    Halpern, Malka; Izhaki, Ido

    2017-01-01

    Vibrio cholerae, the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae. So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. cholerae O1 was reported in a few cases. In most cases V. cholerae was isolated from fish intestines, but it has also been detected in gills, skin, kidney, liver and brain tissue. In most cases the fish were healthy but in some, they were diseased. Nevertheless, Koch postulates were not applied to prove that V. cholerae and not another agent was the cause of the disease in the fish. Evidence from the literature correlates raw fish consumption or fish handling to a few cholera cases or cholera epidemics. Thus, we can conclude that V. cholerae inhabits some marine and freshwater fish species. It is possible that fish may protect the bacteria in unfavorable habitats while the bacteria may assist the fish to digest its food. Also, fish may disseminate the bacteria in the aquatic environment and may transfer it to waterbirds that consume them. Thus, fish are reservoirs of V. cholerae and may play a role in its global dissemination. PMID:28293221

  4. Binding of cholera toxin to Giardia lamblia.

    OpenAIRE

    McCardell, B. A.; Madden, J M; Stanfield, J T; Tall, B D; Stephens, M. J.

    1987-01-01

    Binding of cholera toxin to Giardia lamblia was demonstrated by two slightly different methods: an immunofluorescence technique using antibody to cholera toxin and anti-rabbit immunoglobulin G conjugated to fluorescein isothiocyanate, and a one-step fluorescence method in which G. lamblia was incubated with the B subunit of cholera toxin conjugated to fluorescein isothiocyanate.

  5. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V. cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  6. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse d

  7. Hydroclimatic mechanisms of cholera transmission in the Bengal Delta

    Science.gov (United States)

    Tretkoff, Ernie

    2011-07-01

    Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in the fall following the wet season. However, the large-scale hydroclimatic processes underlying the propagation of the disease have not been well understood. Akanda et al. show that cholera outbreaks in the Bengal Delta region propagate from the coast to inland and from spring to fall following two distinct transmission cycles. The first outbreak begins in the spring near the coast when northward movement of plankton-rich seawater and increasing salinity promote the growth of cholera-causing bacteria in rivers, which are used for irrigation, sanitation, and consumption. The second outbreak begins in the fall, after summer floods and monsoons affect sanitation conditions that aid in bacterial transmission by contaminating waters over much of Bangladesh. (Water Resources Research, doi:10.1029/ 2010WR009914, 2011)

  8. The Bacillus anthracis cholesterol-dependent cytolysin, Anthrolysin O, kills human neutrophils, monocytes and macrophages

    Directory of Open Access Journals (Sweden)

    Rest Richard F

    2006-06-01

    Full Text Available Abstract Background Bacillus anthracis is an animal and human pathogen whose virulence is characterized by lethal and edema toxin, as well as a poly-glutamic acid capsule. In addition to these well characterized toxins, B. anthracis secretes several proteases and phospholipases, and a newly described toxin of the cholesterol-dependent cytolysin (CDC family, Anthrolysin O (ALO. Results In the present studies we show that recombinant ALO (rALO or native ALO, secreted by viable B. anthracis, is lethal to human primary polymorphonuclear leukocytes (PMNs, monocytes, monocyte-derived macrophages (MDMs, lymphocytes, THP-1 monocytic human cell line and ME-180, Detroit 562, and A549 epithelial cells by trypan blue exclusion or lactate dehydrogenase (LDH release viability assays. ALO cytotoxicity is dose and time dependent and susceptibility to ALO-mediated lysis differs between cell types. In addition, the viability of monocytes and hMDMs was assayed in the presence of vegetative Sterne strains 7702 (ALO+, UT231 (ALO-, and a complemented strain expressing ALO, UT231 (pUTE544, and was dependent upon the expression of ALO. Cytotoxicity of rALO is seen as low as 0.070 nM in the absence of serum. All direct cytotoxic activity is inhibited by the addition of cholesterol or serum concentration as low as 10%. Conclusion The lethality of rALO and native ALO on human monocytes, neutrophils, macrophages and lymphocytes supports the idea that ALO may represent a previously unidentified virulence factor of B. anthracis. The study of other factors produced by B. anthracis, along with the major anthrax toxins, will lead to a better understanding of this bacterium's pathogenesis, as well as provide information for the development of antitoxin vaccines for treating and preventing anthrax.

  9. Group B streptococcal beta-hemolysin/cytolysin directly impairs cardiomyocyte viability and function.

    Directory of Open Access Journals (Sweden)

    Mary E Hensler

    Full Text Available BACKGROUND: Group B Streptococcus (GBS is a leading cause of neonatal sepsis where myocardial dysfunction is an important contributor to poor outcome. Here we study the effects of the GBS pore-forming beta-hemolysin/cytolysin (Bh/c exotoxin on cardiomyocyte viability, contractility, and calcium transients. METHODOLOGY/PRINCIPAL FINDINGS: HL-1 cardiomyocytes exposed to intact wild-type (WT or isogenic Deltabeta h/c mutant GBS, or to cell-free extracts from either strain, were assessed for viability by trypan blue exclusion and for apoptosis by TUNEL staining. Functionality of exposed cardiomyocytes was analyzed by visual quantitation of the rate and extent of contractility. Mitochondrial membrane polarization was measured in TMRE-loaded cells exposed to GBS beta h/c. Effects of GBS beta h/c on calcium transients were studied in fura-2AM-loaded primary rat ventricular cardiomyocytes. Exposure of HL-1 cardiomyocytes to either WT GBS or beta h/c extracts significantly reduced both rate and extent of contractility and later induced necrotic and apoptotic cell death. No effects on cardiomyocyte viability or function were observed after treatment with Deltabeta h/c mutant bacteria or extracts. The beta h/c toxin was associated with complete and rapid loss of detectable calcium transients in primary neonatal rat ventricular cardiomyocytes and induced a loss of mitochondrial membrane polarization. These effects on viability and function were abrogated by the beta h/c inhibitor, dipalmitoyl phosphatidylcholine (DPPC. CONCLUSIONS/SIGNIFICANCE: Our data show a rapid loss of cardiomyocyte viability and function induced by GBS beta h/c, and these deleterious effects are inhibited by DPPC, a normal constituent of human pulmonary surfactant.. These findings have clinical implications for the cardiac dysfunction observed in neonatal GBS infections.

  10. Chromosome segregation in Vibrio cholerae.

    Science.gov (United States)

    Ramachandran, Revathy; Jha, Jyoti; Chattoraj, Dhruba K

    2014-01-01

    The study of chromosome segregation is currently one of the most exciting research frontiers in cell biology. In this review, we discuss our current knowledge of the chromosome segregation process in Vibrio cholerae, based primarily on findings from fluorescence microscopy experiments. This bacterium is of special interest because of its eukaryotic feature of having a divided genome, a feature shared with 10% of known bacteria. We also discuss how the segregation mechanisms of V. cholerae compare with those in other bacteria, and highlight some of the remaining questions regarding the process of bacterial chromosome segregation.

  11. Epidemiology of cholera in the Philippines.

    Directory of Open Access Journals (Sweden)

    Anna Lena Lopez

    2015-01-01

    Full Text Available Despite being a cholera-endemic country, data on cholera in the Philippines remain sparse. Knowing the areas where cholera is known to occur and the factors that lead to its occurrence will assist in planning preventive measures and disaster mitigation.Using sentinel surveillance data, PubMed and ProMED searches covering information from 2008-2013 and event-based surveillance reports from 2010-2013, we assessed the epidemiology of cholera in the Philippines. Using spatial log regression, we assessed the role of water, sanitation and population density on the incidence of cholera.We identified 12 articles from ProMED and none from PubMed that reported on cholera in the Philippines from 2008 to 2013. Data from ProMed and surveillance revealed 42,071 suspected and confirmed cholera cases reported from 2008 to 2013, among which only 5,006 were confirmed. 38 (47% of 81 provinces and metropolitan regions reported at least one confirmed case of cholera and 32 (40% reported at least one suspected case. The overall case fatality ratio in sentinel sites was 0.62%, but was 2% in outbreaks. All age groups were affected. Using both confirmed and suspected cholera cases, the average annual incidence in 2010-2013 was 9.1 per 100,000 population. Poor access to improved sanitation was consistently associated with higher cholera incidence. Paradoxically, access to improved water sources was associated with higher cholera incidence using both suspected and confirmed cholera data sources. This finding may have been due to the breakdown in the infrastructure and non-chlorination of water supplies, emphasizing the need to maintain public water systems.Our findings confirm that cholera affects a large proportion of the provinces in the country. Identifying areas most at risk for cholera will support the development and implementation of policies to minimize the morbidity and mortality due to this disease.

  12. Cholera toxin and pregnancy promote regeneration of the retinal ganglion cells in golden hamster%霍乱毒素及妊娠对金黄地鼠视网膜节细胞再生的作用

    Institute of Scientific and Technical Information of China (English)

    李飞; 黄锦桃; 李海标

    2011-01-01

    目的:观察霍乱毒素(CTx)及妊娠对成年金黄地鼠视神经扎断后视网膜节细胞(RGCs)轴突再生的促进作用.方法:确定成年金黄地鼠交配3d后,扎断视神经(ON)近端,玻璃体内注射CTx.动物随机分为实验组和对照组:对照组为单纯扎断ON为损伤组、损伤PBS组;实验组分为CTx组与妊娠后扎断ON妊娠损伤组与妊娠CTx组.术后动物存活3周.用荧光金逆行标记再生的视网膜节细胞( RGCs),在荧光镜下观察视网膜平铺片再生RGCs的数量变化,并比较实验组各组再生RGCs的周长.结果:CTx组、妊娠损伤组、妊娠CTx组视网膜再生RGCs平均数比损伤组及PBS组增加,差异具有统计学意义.妊娠CTx组比CTx组、妊娠损伤组视网膜再生RGCs平均数增加.实验组各组再生的RGCs周长相比差异无统计学意义.结论:妊娠及玻璃体注入CTx具有促进视神经扎断后视网膜节细胞轴突再生的作用,两者有协同作用,各组再生的RGCs大小无明显差别.%Objective: To investigate the effects of cholera toxin (CTx) and pregnancy on promoting the axon regeneration of retinal ganglion cells (RGCs) in hamster retina. Methods: In day 3 after golden hamster mating, optic nerve (ON) micro-crushed, CTx was injected intravitrously. The rats were separated into a regenerating control group (injuried group and in-juried+PBS group) and an experiment group (injuried+CTx group, pregnancy + injuried group, pregnancy+injuried+CTx group). The rats in each group were allowed to survive for 3 weeks. The regenerating RGCs were labeled retrogradely with fluorogold, and changes in number of regenerating RGCs in each retina were observed under a fluorescence microscope. The circumference of regenerating RGCs in each experimental group was compared. Results: The mean numbers of regenerating RGCs in the injuried+CTx group, pregnancy + injuried group and pregnancy+injuried+CTx group were increased and significantly higher than those in the

  13. 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.

  14. Maladi Kolera PSA (:60) (Cholera)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about ways you can prevent the spread of cholera. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  15. Cholera in the United States

    Centers for Disease Control (CDC) Podcasts

    2011-11-08

    Anna Newton, Surveillance Epidemiologist at CDC, discusses cholera that was brought to the United States during an outbreak in Haiti and the Dominican Republic (Hispaniola).  Created: 11/8/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/8/2011.

  16. Dynamics in genome evolution of Vibrio cholerae.

    Science.gov (United States)

    Banerjee, Rachana; Das, Bhabatosh; Balakrish Nair, G; Basak, Surajit

    2014-04-01

    Vibrio cholerae, the etiological agent of the acute secretary diarrheal disease cholera, is still a major public health concern in developing countries. In former centuries cholera was a permanent threat even to the highly developed populations of Europe, North America, and the northern part of Asia. Extensive studies on the cholera bug over more than a century have made significant advances in our understanding of the disease and ways of treating patients. V. cholerae has more than 200 serogroups, but only few serogroups have caused disease on a worldwide scale. Until the present, the evolutionary relationship of these pandemic causing serogroups was not clear. In the last decades, we have witnessed a shift involving genetically and phenotypically varied pandemic clones of V. cholerae in Asia and Africa. The exponential knowledge on the genome of several representatives V. cholerae strains has been used to identify and analyze the key determinants for rapid evolution of cholera pathogen. Recent comparative genomic studies have identified the presence of various integrative mobile genetic elements (IMGEs) in V. cholerae genome, which can be used as a marker of differentiation of all seventh pandemic clones with very similar core genome. This review attempts to bring together some of the important researches in recent times that have contributed towards understanding the genetics, epidemiology and evolution of toxigenic V. cholerae strains.

  17. How Will Climate Change Impact Cholera Outbreaks?

    Science.gov (United States)

    Nasr Azadani, F.; Jutla, A.; Rahimikolu, J.; Akanda, A. S.; Huq, A.; Colwell, R. R.

    2014-12-01

    Environmental parameters associated with cholera are well documented. However, cholera continues to be a global public health threat. Uncertainty in defining environmental processes affecting growth and multiplication of the cholera bacteria can be affected significantly by changing climate at different temporal and spatial scales, either through amplification of the hydroclimatic cycle or by enhanced variability of large scale geophysical processes. Endemic cholera in the Bengal Delta region of South Asia has a unique pattern of two seasonal peaks and there are associated with asymmetric and episodic variability in river discharge. The first cholera outbreak in spring is related with intrusion of bacteria laden coastal seawater during low river discharge. Cholera occurring during the fall season is hypothesized to be associated with high river discharge related to a cross-contamination of water resources and, therefore, a second wave of disease, a phenomenon characteristic primarily in the inland regions. Because of difficulties in establishing linkage between coarse resolutions of the Global Climate Model (GCM) output and localized disease outbreaks, the impact of climate change on diarrheal disease has not been explored. Here using the downscaling method of Support Vector Machines from HADCM3 and ECHAM models, we show how cholera outbreak patterns are changing in the Bengal Delta. Our preliminary results indicate statistically significant changes in both seasonality and magnitude in the occurrence of cholera over the next century. Endemic cholera is likely to transform into epidemic forms and new geographical areas will be at risk for cholera outbreaks.

  18. A novel imageable therapeutic probe for cancer; cytolysin a expressing attenuated salmonella typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Vu Hong; Tae, Seong Ho; Piao, Hong Hua; Hong, Yeoung Jin; Choy, Hyon E.; Bom, Hee Seung; Min, Jung Joon [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-07-01

    Oncolytic strategy using bacteria has a long history. With the discovery of fluorescent and luminescent reporter genes, bacteria can be easily monitored continuously in treatment process. Salmonella typhimurium ppGpp mutant, one of the prominent attenuated bacteria, has just reported recently, Therefore, in this study, we established strain Cytolysin A (Cly A) expressing light-emitting S. typhimurium ppGpp mutant. S. typhimurium ppGpp mutant was transducted by lux gene for in vivo imaging (S. typhimurium ppGpp/lux) and then, plasmid containing ClyA gene, which is encoded for a pore-forming protein toxin, was transformed to create the strain expressing haemolytic activity (S. typhimurium ppGpp/lux/ClyA). The toxicity of ClyA was evaluated in vitro by inoculating the bacteria with various cultured cancer cell lines. On the other hand, to test the therapeutic effect, the bacteria were injected intermittently, intraperitoneal y or intravenously into CT26-bearing Balb/c mice. The sizes of tumors were measured and in vivo imaging was taken everyday by IVIS machine (Xenogen). The in vitro result showed the number of death cells were significantly higher in the samples containing S. typhimurium ppGpp/lux/ClyA compared with the samples containing S. typhimurium ppGpp/lux. After two days injection, the growth of tumors were repressed in mice injected with either S. typhimurium ppGpp/lux/ClyA or S. typhimurium ppGpp/lux, while tumors in control group still grew fast. In day 3, the tumors inoculated with S. typhimurium ppGpp/lux/ClyA became necrosis and regressed in the following days but not in other groups. In addition, in vivo imaging data showed that the Salmonella strains selectively located in the tumor. By in vivo imaging technique, the light-emitting bacteria can be easily monitored and quantified non-invasively and repeatedly. And ClyA expressing light-emitting S. typhimurium ppGpp mutant can become an effective and safely candidate for cancer treatment.

  19. Cytolysin a expressing E. coli a promising candidate for imageable therapeutic probe

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Vu Hong; Phan, Thuy Xuan; Hong, Yeoung Jin; Min, Jung Joon [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-07-01

    Using bacteria for cancer treatment has a long history. Discovery of optical reporter genes consisting of fluorescent and luminescent protein facilitates the monitor of bacteria in vivo, non-invasively and repeatedly. E. coli, the natural enteric bacteria possessing capacity of tumor-targeting ability, seems to be suitable candidate for cancer treatment. In this study, we established the strain light-emitting E. coli for diagnostic purpose and Cytolysin A (Cly A) expressing E. coli for therapeutic purpose. E. coli (MG1655, wild type strain) was transformed plasmid pUC19 carrying lux gene to create the light expressing bacteria and test the tumor targeting-capacity by injecting the bacteria into CT26-tumor bearing mice via tail vein. On the other hand, for therapeutic purpose, plasmid containing Cly A gene, which is encoded for a pore-forming protein toxin, was introduced into E. coli. The toxicity of Cly A was evaluated in vitro by inoculating the bacteria with various cultured cancer cell lines. On the other hand, to test the therapeutic effect, the bacteria were injected intratumorally and intravenously into s.c.CT26-bearing as well as CT26-lung metastasized Balb/c mice. In vivo imaging data showed that the E. coli strains selectively located in the tumor. The in vitro result showed that the number of death cells were significantly higher in the samples containing E. coli expressing Cly A (E. coli Cly A) compared with the samples containing wild type strain. The growth of tumors was repressed in mice injected with either E. coli Cly A (significantly) or wild type E. coli (mildly), while tumors in no treatment group still grew fast. Furthermore, the tumors inoculated with E. coli cly A were necrotized but not with wild type E. coli. In the CT26-lung metastasized mouse model, the life span of mice was elongated when inject E. coli and longer in the group injected with E. coli cly A. Cly A expressing E. coli can become an effective candidate for imageable

  20. Cholera epidemic threatens Sierra Leone.

    Science.gov (United States)

    Dyer, O

    1995-07-08

    Sierra Leone faces the threat of a major epidemic of cholera with the onset of the rainy season, according to the World Health Organization (WHO). The situation is particularly grave for the two million people displaced by the country's civil war. Already 1709 cases of cholera have been registered in Freetown, with 57 deaths. Freetown's population has doubled since the start of the war in 1991 with 750,000 refugees camping out in the town. The insurgent Revolutionary United Front is now within 32 km of the capital. Provinces are cut off from the capital, medical supplies are scarce. Doctors and aid workers are forced to rely on a private helicopter service for personal transport. As many as 10,000 people were affected by the disease last year. WHO experts predict that pneumonia is likely to claim the lives of many children, and a highly drug resistant strain of Plasmodium falciparum malaria is also looming. The greatest problems are the lack of safe drinking water and the attendant risks of cholera and dysentery. At one site in Freetown the 6000 refugees have to fetch water from a well and have no latrines. As a result there have been 277 cases of cholera and 2 deaths already among that group. The health department has set up five centers to treat cholera in Freetown and is organizing mobile clinics. WHO's Sierra Leone office is assisting the government mobile health teams, which provide free primary care to displaced people. Medicines and vaccines, however, are lacking. Many of the staff of the 13 district health authorities have been displaced to Freetown. Aid agencies such as Medecins Sans Frontieres and Oxfam have stepped into the role in many districts. Ironically, one of the Revolutionary United Front's main demands is for a free national health service.

  1. High-frequency rugose exopolysaccharide production by Vibrio cholerae strains isolated in Haiti.

    Science.gov (United States)

    Rahman, Mustafizur; Jubair, Mohammad; Alam, Meer T; Weppelmann, Thomas A; Azarian, Taj; Salemi, Marco; Sakharuk, Ilya A; Rashid, Mohammed H; Johnson, Judith A; Yasmin, Mahmuda; Morris, J Glenn; Ali, Afsar

    2014-01-01

    In October, 2010, epidemic cholera was reported for the first time in Haiti in over 100 years. Establishment of cholera endemicity in Haiti will be dependent in large part on the continued presence of toxigenic V. cholerae O1 in aquatic reservoirs. The rugose phenotype of V. cholerae, characterized by exopolysaccharide production that confers resistance to environmental stress, is a potential contributor to environmental persistence. Using a microbiologic medium promoting high-frequency conversion of smooth to rugose (S-R) phenotype, 80 (46.5%) of 172 V. cholerae strains isolated from clinical and environmental sources in Haiti were able to convert to a rugose phenotype. Toxigenic V. cholerae O1 strains isolated at the beginning of the epidemic (2010) were significantly less likely to shift to a rugose phenotype than clinical strains isolated in 2012/2013, or environmental strains. Frequency of rugose conversion was influenced by incubation temperature and time. Appearance of the biofilm produced by a Haitian clinical rugose strain (altered biotype El Tor HC16R) differed from that of a typical El Tor rugose strain (N16961R) by confocal microscopy. On whole-genome SNP analysis, there was no phylogenetic clustering of strains showing an ability to shift to a rugose phenotype. Our data confirm the ability of Haitian clinical (and environmental) strains to shift to a protective rugose phenotype, and suggest that factors such as temperature influence the frequency of transition to this phenotype.

  2. High-frequency rugose exopolysaccharide production by Vibrio cholerae strains isolated in Haiti.

    Directory of Open Access Journals (Sweden)

    Mustafizur Rahman

    Full Text Available In October, 2010, epidemic cholera was reported for the first time in Haiti in over 100 years. Establishment of cholera endemicity in Haiti will be dependent in large part on the continued presence of toxigenic V. cholerae O1 in aquatic reservoirs. The rugose phenotype of V. cholerae, characterized by exopolysaccharide production that confers resistance to environmental stress, is a potential contributor to environmental persistence. Using a microbiologic medium promoting high-frequency conversion of smooth to rugose (S-R phenotype, 80 (46.5% of 172 V. cholerae strains isolated from clinical and environmental sources in Haiti were able to convert to a rugose phenotype. Toxigenic V. cholerae O1 strains isolated at the beginning of the epidemic (2010 were significantly less likely to shift to a rugose phenotype than clinical strains isolated in 2012/2013, or environmental strains. Frequency of rugose conversion was influenced by incubation temperature and time. Appearance of the biofilm produced by a Haitian clinical rugose strain (altered biotype El Tor HC16R differed from that of a typical El Tor rugose strain (N16961R by confocal microscopy. On whole-genome SNP analysis, there was no phylogenetic clustering of strains showing an ability to shift to a rugose phenotype. Our data confirm the ability of Haitian clinical (and environmental strains to shift to a protective rugose phenotype, and suggest that factors such as temperature influence the frequency of transition to this phenotype.

  3. Actions of cholera toxin and the prevention and treatment of cholera

    Science.gov (United States)

    Holmgren, Jan

    1981-07-01

    The drastic intestinal secretion of fluid and electrolytes that is characteristic of cholera is the result of reasonably well understood cellular and biochemical actions of the toxin secreted by Vibrio cholerae. Based on this understanding it is possible to devise new techniques for the treatment and prophylaxis of cholera to complement those based on fluid replacement therapy and sanitation.

  4. Outbreak investigation of cholera in Bharuch city

    Directory of Open Access Journals (Sweden)

    Navneet G. Padhiyar, Jivraj Damor

    2011-01-01

    Full Text Available Introduction: Cholera is an acute diarrhoeal disease, present in India since ancient times. Cholera epidemic was reported in June 2009 in Bharuch city, Gujarat. Aim: To find out the cause of cholera epidemic and to suggest preventive and control measure. Study design: Cross sectional study. Person from high risk area were interviewed Results: Contamination of drinking water with sewage water was found to be the cause of this epidemic.

  5. Controlling endemic cholera with oral vaccines.

    Directory of Open Access Journals (Sweden)

    Ira M Longini

    2007-11-01

    Full Text Available BACKGROUND: Although advances in rehydration therapy have made cholera a treatable disease with low case-fatality in settings with appropriate medical care, cholera continues to impose considerable mortality in the world's most impoverished populations. Internationally licensed, killed whole-cell based oral cholera vaccines (OCVs have been available for over a decade, but have not been used for the control of cholera. Recently, these vaccines were shown to confer significant levels of herd protection, suggesting that the protective potential of these vaccines has been underestimated and that these vaccines may be highly effective in cholera control when deployed in mass immunization programs. We used a large-scale stochastic simulation model to investigate the possibility of controlling endemic cholera with OCVs. METHODS AND FINDINGS: We construct a large-scale, stochastic cholera transmission model of Matlab, Bangladesh. We find that cholera transmission could be controlled in endemic areas with 50% coverage with OCVs. At this level of coverage, the model predicts that there would be an 89% (95% confidence interval [CI] 72%-98% reduction in cholera cases among the unvaccinated, and a 93% (95% CI 82%-99% reduction overall in the entire population. Even a more modest coverage of 30% would result in a 76% (95% CI 44%-95% reduction in cholera incidence for the population area covered. For populations that have less natural immunity than the population of Matlab, 70% coverage would probably be necessary for cholera control, i.e., an annual incidence rate of < or = 1 case per 1,000 people in the population. CONCLUSIONS: Endemic cholera could be reduced to an annual incidence rate of < or = 1 case per 1,000 people in endemic areas with biennial vaccination with OCVs if coverage could reach 50%-70% depending on the level of prior immunity in the population. These vaccination efforts could be targeted with careful use of ecological data.

  6. Cholera outbreak--southern Sudan, 2007.

    Science.gov (United States)

    2009-04-10

    Vibrio cholerae causes cholera, an acute infectious diarrheal disease that can result in death without appropriate therapy, depending on the severity of the disease. War, poverty, inadequate sanitation, and large numbers of refugees and internally displaced persons (IDPs) are major precursors to cholera outbreaks. In 2005, Southern Sudan ended its 22-year civil war with North Sudan; as a result, IDPs and refugees are returning to the south. During April--June 2007, investigators from the Southern Sudan Field Epidemiology and Laboratory Training Program (SS-FELTP) and CDC investigated a cholera outbreak in the town of Juba, Southern Sudan. This report summarizes the results of that investigation, which found that 3,157 persons were diagnosed with suspected cholera during January--June 2007, with 74 deaths resulting from the disease. An environmental investigation revealed suboptimal hygiene practices and a lack of water and sanitation infrastructure in Juba. A case-control study indicated that persons less likely to have cholera were more likely to have consumed hot meals containing meat during the outbreak. Contaminated food or water were not identified as possible sources of the cholera outbreak in Juba. However, this might be attributed to limitations of the study, including small sample size. Cholera can reach epidemic proportions if adequate control measures are not implemented early. Mass media campaigns are important for current and new residents in Juba to understand the importance of proper food handling, clean water, and optimal hygiene practices to prevent the spread of cholera.

  7. Cost-effectiveness of oral cholera vaccine in a stable refugee population at risk for epidemic cholera and in a population with endemic cholera.

    OpenAIRE

    Murray, J.; McFarland, D. A.; Waldman, R. J.

    1998-01-01

    Recent large epidemics of cholera with high incidence and associated mortality among refugees have raised the question of whether oral cholera vaccines should be considered as an additional preventive measure in high-risk populations. The potential impact of oral cholera vaccines on populations prone to seasonal endemic cholera has also been questioned. This article reviews the potential cost-effectiveness of B-subunit, killed whole-cell (BS-WC) oral cholera vaccine in a stable refugee popula...

  8. The Unique Molecular Choreography of Giant Pore Formation by the Cholesterol-Dependent Cytolysins of Gram-Positive Bacteria.

    Science.gov (United States)

    Tweten, Rodney K; Hotze, Eileen M; Wade, Kristin R

    2015-01-01

    The mechanism by which the cholesterol-dependent cytolysins (CDCs) assemble their giant β-barrel pore in cholesterol-rich membranes has been the subject of intense study in the past two decades. A combination of structural, biophysical, and biochemical analyses has revealed deep insights into the series of complex and highly choreographed secondary and tertiary structural transitions that the CDCs undergo to assemble their β-barrel pore in eukaryotic membranes. Our knowledge of the molecular details of these dramatic structural changes in CDCs has transformed our understanding of how giant pore complexes are assembled and has been critical to our understanding of the mechanisms of other important classes of pore-forming toxins and proteins across the kingdoms of life. Finally, there are tantalizing hints that the CDC pore-forming mechanism is more sophisticated than previously imagined and that some CDCs are employed in pore-independent processes.

  9. Serotype cycles in cholera dynamics

    OpenAIRE

    Koelle, Katia; Pascual, Mercedes; Yunus, Md.

    2006-01-01

    Interest in understanding strain diversity and its impact on disease dynamics has grown over the past decade. Theoretical disease models of several co-circulating strains indicate that incomplete cross-immunity generates conditions for strain-cycling behaviour at the population level. However, there have been no quantitative analyses of disease time-series that are clear examples of theoretically expected strain cycling. Here, we analyse a 40-year (1966–2005) cholera time-series from Banglade...

  10. Vibrio cholerae-induced inflammation in the neonatal mouse cholera model.

    Science.gov (United States)

    Bishop, Anne L; Patimalla, Bharathi; Camilli, Andrew

    2014-06-01

    Vibrio cholerae is the causative agent of the acute diarrheal disease of cholera. Innate immune responses to V. cholerae are not a major cause of cholera pathology, which is characterized by severe, watery diarrhea induced by the action of cholera toxin. Innate responses may, however, contribute to resolution of infection and must be required to initiate adaptive responses after natural infection and oral vaccination. Here we investigated whether a well-established infant mouse model of cholera can be used to observe an innate immune response. We also used a vaccination model in which immunized dams protect their pups from infection through breast milk antibodies to investigate innate immune responses after V. cholerae infection for pups suckled by an immune dam. At the peak of infection, we observed neutrophil recruitment accompanied by induction of KC, macrophage inflammatory protein 2 (MIP-2), NOS-2, interleukin-6 (IL-6), and IL-17a. Pups suckled by an immunized dam did not mount this response. Accessory toxins RtxA and HlyA played no discernible role in neutrophil recruitment in a wild-type background. The innate response to V. cholerae deleted for cholera toxin-encoding phage (CTX) and part of rtxA was significantly reduced, suggesting a role for CTX-carried genes or for RtxA in the absence of cholera toxin (CTX). Two extracellular V. cholerae DNases were not required for neutrophil recruitment, but DNase-deficient V. cholerae caused more clouds of DNA in the intestinal lumen, which appeared to be neutrophil extracellular traps (NETs), suggesting that V. cholerae DNases combat NETs. Thus, the infant mouse model has hitherto unrecognized utility for interrogating innate responses to V. cholerae infection.

  11. Molecular mechanism of acquisition of the cholera toxin genes.

    Science.gov (United States)

    Das, Bhabatosh; Bischerour, Julien; Barre, Francois-Xavier

    2011-02-01

    One of the major pathogenic determinants of Vibrio cholerae, the cholera toxin, is encoded in the genome of a filamentous phage, CTXφ. CTXφ makes use of the chromosome dimer resolution system of V. cholerae to integrate its single stranded genome into one, the other, or both V. cholerae chromosomes. Here, we review current knowledge about this smart integration process.

  12. 9 CFR 311.3 - Hog cholera.

    Science.gov (United States)

    2010-01-01

    ... of hog cholera observed during the ante-mortem inspection of a U.S. suspect shall be duly considered in connection with post-mortem findings and when the carcass of such a suspect shows lesions in the kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of...

  13. Tetra- versus Pentavalent Inhibitors of Cholera Toxin

    NARCIS (Netherlands)

    Fu, Ou; Pukin, Aliaksei V.; Quarles Van Ufford, Linda; Branson, Thomas R.; Thies-Weesie, Dominique M E; Turnbull, W. Bruce; Visser, Gerben M.; Pieters, Roland J.

    2015-01-01

    The five B-subunits (CTB5) of the Vibrio cholerae (cholera) toxin can bind to the intestinal cell surface so the entire AB5 toxin can enter the cell. Simultaneous binding can occur on more than one of the monosialotetrahexosylganglioside (GM1) units present on the cell surface.

  14. [Cholera epidemiology in Mozambique: 1973-1992].

    Science.gov (United States)

    Aragón, M; Barreto, A; Tabbard, P; Chambule, J; Santos, C; Noya, A

    1994-10-01

    The results of an epidemiological analysis of cholera in Mozambique from 1973 to 1992 are described. The project sought to assess the influence of socio-economic and ecological factors the spread of cholera in a country at war. Information about the incidence of cholera and the fatality rate were related to the rainfall and the annual average growth rate of the population in the main cities. Water supply, sanitation and food hygiene were also studied. The high annual average growth rate of the population was found to have a direct linear correlation to the incidence of cholera. The drought of 1991-1992 also played an important role in the increased number of cases of the disease. Cholera has presented an endemic-epidemic pattern determined by: a) the uncontrolled growth of urban population, b) the deterioration of sanitation in urban centers, c) the unhygienic commercialization of food and d) the drought.

  15. Seasonal dynamics of Vibrio cholerae and its phages in riverine ecosystem of Gangetic West Bengal: cholera paradigm.

    Science.gov (United States)

    Mookerjee, Subham; Jaiswal, Abhishek; Batabyal, Prasenjit; Einsporn, Marc H; Lara, Ruben J; Sarkar, Banwarilal; Neogi, Sucharit Basu; Palit, Anup

    2014-10-01

    The Gangetic delta is a century-old cholera endemic belt where the role of riverine-estuarine ecosystem in cholera transmission has never been elucidated. Seasonality, distribution, and abundance of environmental Vibrio cholerae O1/O139 and vibriophage in Hooghly riverine-estuarine environment and their correlation with cholera incidence pattern in West Bengal, India, have been analyzed for the first time across summer, monsoon, and winter months. A total of 146 water samples collected from two sites of the Hooghly River (Howrah and Diamond Harbour) were analyzed physicochemically along with cultivable Vibrio count (CVC), V. cholerae O1/O139, and vibriophages. V. cholerae O1 was detected in 56 (38.3%) samples, while 66 (45.2%) were positive for V. cholerae O1 phages. Flood tide, water temperature (31 ± 1.6 °C), and turbidity (≥250 nephelometric turbidity unit (NTU)) significantly stimulated V. cholerae and vibriophage abundance in riverine ecosystem. Solitary existence of V. cholerae O1 and phages (p V. cholerae O1 or V. cholerae O1 Φ) on the other. Significant association (p cholera cases and V. cholerae O1 in aquatic environment implies the role of riverine-estuarine ecosystem in cholera transmission. A "biomonitoring tool" of physicochemical stimulants, tidal, and climatic variants has been proposed collating V. cholerae and phage dynamics that can forewarn any impending cholera outbreak.

  16. Spatial dependency of cholera prevalence on potential cholera reservoirs in an urban area, Kumasi, Ghana

    Science.gov (United States)

    Osei, Frank B.; Duker, Alfred A.; Augustijn, Ellen-Wien; Stein, Alfred

    2010-10-01

    Cholera has been a public health burden in Ghana since the early 1970s. Between 1999 and 2005, a total of 25,636 cases and 620 deaths were officially reported to the WHO. In one of the worst affected urban cities, fecal contamination of surface water is extremely high, and the disease is reported to be prevalent among inhabitants living in close proximity to surface water bodies. Surface runoff from dump sites is a major source of fecal and bacterial contamination of rivers and streams in the study area. This study aims to determine (a) the impacts of surface water contamination on cholera infection and (b) detect and map arbitrary shaped clusters of cholera. A Geographic Information System (GIS) based spatial analysis is used to delineate potential reservoirs of the cholera vibrios; possibly contaminated by surface runoff from open space refuse dumps. Statistical modeling using OLS model reveals a significant negative association between (a) cholera prevalence and proximity to all the potential cholera reservoirs ( R2 = 0.18, p cholera prevalence and proximity to upstream potential cholera reservoirs ( R2 = 0.25, p cholera prevalence on the spatial neighbors of the communities. A flexible scan statistic identifies a most likely cluster with a higher relative risk (RR = 2.04, p cholera infection.

  17. Zinc: Role in the management of diarrhea and cholera

    OpenAIRE

    Qadir, M Imran; Arshad, Arfa; Ahmad, Bashir

    2013-01-01

    Diarrhea and cholera are major health problems. Vibrio cholera, the causative agent of cholera, infects the small intestine, resulting in vomiting, massive watery diarrhea and dehydration. Reduced water and electrolyte absorption is also due to zinc deficiency. Zinc has an important role in recovery from the disease. The combination of zinc with cholera vaccine and oral rehydration solutions has a positive impact on cholera and diarrhea. It has led to a decrease in the mortality and morbidity...

  18. Cholera outbreaks in the classical biotype era.

    Science.gov (United States)

    Siddique, A K; Cash, Richard

    2014-01-01

    In the Indian subcontinent description of a disease resembling cholera has been mentioned in Sushruta Samita, estimated to have been written between ~400 and 500 BC. It is however not clear whether the disease known today as cholera caused by Vibrio cholerae Vibrio cholerae O1 is the evolutionary progression of the ancient disease. The modern history of cholera began in 1817 when an explosive epidemic broke out in the Ganges River Delta region of Bengal. This was the first of the seven recorded cholera pandemics cholera pandemics that affected nearly the entire world and caused hundreds of thousands of deaths. The bacterium responsible for this human disease was first recognised during the fifth pandemic and was named V. cholerae which was grouped as O1, and was further differentiated into Classical and El Tor biotypes. It is now known that the fifth and the sixth pandemics were caused by the V. cholerae O1 of the Classical biotype Classical biotype and the seventh by the El Tor biotype El Tor biotype . The El Tor biotype of V. cholerae, which originated in Indonesia Indonesia and shortly thereafter began to spread in the early 1960s. Within the span of 50 years the El Tor biotype had invaded nearly the entire world, completely displacing the Classical biotype from all the countries except Bangladesh. What prompted the earlier pandemics to begin is not clearly understood, nor do we know how and why they ended. The success of the seventh pandemic clone over the pre-existing sixth pandemic strain remains largely an unsolved mystery. Why classical biotype eventually disappeared from the world remains to be explained. For nearly three decades (1963-1991) during the Seventh cholera pandemic seventh pandemic, cholera in Bangladesh has recorded a unique history of co-existence of Classical and El Tor biotypes of V. cholerae O1 as epidemic and endemic strain. This long co-existence has provided us with great opportunity to improve our understanding of the disease itself

  19. Antitoxic immunity to cholera in dogs immunized orally with cholera toxin.

    Science.gov (United States)

    Pierce, N F; Cray, W C; Engel, P F

    1980-02-01

    Colera toxin was evaluated as an oral immunogen against experimental canine cholera. Dogs were immunized orally with 100-microgram doses of purified cholera toxin or comparable doses of crude toxin. Both doses caused moderate diarrhea in most nonimmune dogs. Repeated oral doses (12 doses in 54 days) gave marked protection against the diarrheal effect of oral toxin, provoked a vigorous antitoxic response in jejunal mucosa, and gave nearly complete protection against subsequent oral challenge with living virulent Vibrio cholerae. Protection appeared to be due largely to the antitoxic response in intestinal mucosa. The effectiveness of cholera toxin as an oral vaccine contrasts with the previously described ineffectiveness of toxoid given orally. This study provides an example of mucosal immunity due to a nonreplicating vaccine given orally and suggests that cholera toxin may be useful as a component of an oral vaccine for cholera.

  20. Swedish isolates of Vibrio cholerae enhance their survival when interacted intracellularly with Acanthamoeba castellanii

    OpenAIRE

    Shanan, Salah; Bayoumi, Magdi; Saeed, Amir; Sandström, Gunnar; Abd, Hadi

    2016-01-01

    Vibrio cholerae is a Gram-negative bacterium that occurs naturally in aquatic environment. Only V. cholerae O1 and V. cholerae O139 produce cholera toxin and cause cholera, other serogroups can cause gastroenteritis, open wounds infection, and septicaemia. V. cholerae O1 and V. cholerae O139 grow and survive inside Acanthamoeba castellanii. The aim of this study is to investigate the interactions of the Swedish clinical isolates V. cholerae O3, V. cholerae O4, V. cholerae O5, V. cholerae O11,...

  1. Biosensing Vibrio cholerae with Genetically Engineered Escherichia coli.

    Science.gov (United States)

    Holowko, Maciej B; Wang, Huijuan; Jayaraman, Premkumar; Poh, Chueh Loo

    2016-11-18

    Cholera is a potentially mortal, infectious disease caused by Vibrio cholerae bacterium. Current treatment methods of cholera still have limitations. Beneficial microbes that could sense and kill the V. cholerae could offer potential alternative to preventing and treating cholera. However, such V. cholerae targeting microbe is still not available. This microbe requires a sensing system to be able to detect the presence of V. cholera bacterium. To this end, we designed and created a synthetic genetic sensing system using nonpathogenic Escherichia coli as the host. To achieve the system, we have moved proteins used by V. cholerae for quorum sensing into E. coli. These sensor proteins have been further layered with a genetic inverter based on CRISPRi technology. Our design process was aided by computer models simulating in vivo behavior of the system. Our sensor shows high sensitivity to presence of V. cholerae supernatant with tight control of expression of output GFP protein.

  2. OxyR-activated expression of Dps is important for Vibrio cholerae oxidative stress resistance and pathogenesis

    Science.gov (United States)

    Xia, Xiaoyun; Larios-Valencia, Jessie; Liu, Zhi; Xiang, Fu; Kan, Biao; Zhu, Jun

    2017-01-01

    Vibrio cholerae is the causative agent of cholera, a dehydrating diarrheal disease. This Gram-negative pathogen is able to modulate its gene expression in order to combat stresses encountered in both aquatic and host environments, including stress posed by reactive oxygen species (ROS). In order to further the understanding of V. cholerae’s transcriptional response to ROS, we performed an RNA sequencing analysis to determine the transcriptional profile of V. cholerae when exposed to hydrogen hydroperoxide. Of 135 differentially expressed genes, VC0139 was amongst the genes with the largest induction. VC0139 encodes a protein homologous to the DPS (DNA-binding protein from starved cells) protein family, which are widely conserved and are implicated in ROS resistance in other bacteria. Using a promoter reporter assay, we show that during exponential growth, dps is induced by H2O2 in a manner dependent on the ROS-sensing transcriptional regulator, OxyR. Upon entry into stationary phase, the major stationary phase regulator RpoS is required to transcribe dps. Deletion of dps impaired V. cholerae resistance to both inorganic and organic hydroperoxides. Furthermore, we show that Dps is involved in resistance to multiple environmental stresses. Finally, we found that Dps is important for V. cholerae adult mouse colonization, but becomes dispensable in the presence of antioxidants. Taken together, our results suggest that Dps plays vital roles in both V. cholerae stress resistance and pathogenesis. PMID:28151956

  3. Transmission of Infectious Vibrio cholerae through Drinking Water among the Household Contacts of Cholera Patients (CHoBI7 Trial)

    Science.gov (United States)

    Rafique, Raisa; Rashid, Mahamud-ur; Monira, Shirajum; Rahman, Zillur; Mahmud, Md. Toslim; Mustafiz, Munshi; Saif-Ur-Rahman, K. M.; Johura, Fatema-Tuz; Islam, Saiful; Parvin, Tahmina; Bhuyian, Md. Sazzadul I.; Sharif, Mohsena B.; Rahman, Sabita R.; Sack, David A.; Sack, R. Bradley; George, Christine M.; Alam, Munirul

    2016-01-01

    Recurrent cholera causes significant morbidity and mortality among the growing population of Dhaka, the capital city of Bangladesh. Previous studies have demonstrated that household contacts of cholera patients are at >100 times higher risk of cholera during the week after the presentation of the index patient. Our prospective study investigated the mode of transmission of Vibrio cholerae, the cause of cholera, in the households of cholera patients in Dhaka city. Out of the total 420 rectal swab samples analyzed from 84 household contacts and 330 water samples collected from 33 households, V. cholerae was isolated from 20%(17/84) of household contacts, 18%(6/33) of stored drinking water, and 27%(9/33) of source water samples. Phenotypic and molecular analyses results confirmed the V. cholerae isolates to be toxigenic and belonging to serogroup O1 biotype El Tor (ET) possessing cholera toxin of classical biotype (altered ET). Phylogenetic analysis by pulsed-field gel electrophoresis (PFGE) showed the V. cholerae isolates to be clonally linked, as >95% similarity was confirmed by sub-clustering patterns in the PFGE (NotI)-based dendrogram. Mapping results showed cholera patients to be widely distributed across 25 police stations. The data suggesting the transmission of infectious V. cholerae within the household contacts of cholera patients through drinking water underscores the need for safe water to prevent spread of cholera and related deaths in Dhaka city. PMID:27803695

  4. Transmission of Infectious Vibrio cholerae Through Drinking Water among the Household Contacts of Cholera Patients (CHoBI7 Trial

    Directory of Open Access Journals (Sweden)

    Raisa Rafique

    2016-10-01

    Full Text Available Recurrent cholera causes significant morbidity and mortality among the growing population of Dhaka, the capital city of Bangladesh. Previous studies have demonstrated that household contacts of cholera patients are at >100 times higher risk of cholera during the week after the presentation of the index patient. Our prospective study investigated the mode of transmission of Vibrio cholerae, the cause of cholera, in the households of cholera patients in Dhaka city. Of total 420 rectal swab samples analyzed from 84 household contacts and 330 water samples collected from 33 households, V. cholerae was isolated from 20%(17/84 of household contacts, 18%(6/33 of stored drinking water, and 27%(9/33 of source water samples. Phenotypic and molecular analyses results confirmed the V. cholerae isolates to be toxigenic and belonging to serogroup O1 biotype El Tor (ET possessing cholera toxin of classical biotype (altered ET. Phylogenetic analysis by pulsed-field gel electrophoresis (PFGE showed the V. cholerae isolates to be clonally linked, as >95% similarity was confirmed by sub-clustering patterns in the PFGE (NotI-based dendrogram. Mapping results showed cholera patients to be widely distributed across 25 police stations with the highest incidence in households near the major rivers and polluted water bodies. The data presented on the transmission of infectious V. cholerae within the household contacts of cholera patients through drinking water underscores the need for safe water to prevent spread of cholera and related deaths in Dhaka city.

  5. Targeting aphA : a new high-throughput screening assay identifies compounds that reduce prime virulence factors of Vibrio cholerae.

    Science.gov (United States)

    Bolger, Galina; Roy, Sambit; Zapol'skii, Viktor A; Kaufmann, Dieter E; Schnürch, Michael; Mihovilovic, Marko D; Nandy, Ranjan K; Tegge, Werner

    2016-07-01

    A high-throughput screening (HTS) assay was developed for identifying compounds with inhibitory effect on aphA, one of the key regulators positively controlling Vibrio cholerae pathogenesis. An inhibitory effect on aphA was expected to lead to attenuation in the secretion of the major pathogenicity factors of V. cholerae, cholera toxin and toxin co-regulated pilus. The plasmid construct pAKSB was developed with a kanamycin resistance (KmR) gene under the control of the aphA -like promoter for conferring a KmR phenotype under aphA -expressing conditions. The HTS assay was performed to identify compounds with inhibitory effect on the growth of O139 V. cholerae MO10 carrying the construct pAKSB in growth medium containing Km (30 g ml-1), but not in its absence. Of 20 338 compounds screened, six compounds were identified to inhibit the pAKSB-induced KmR phenotype and these compounds caused transcriptional inhibition of aphA in V. cholerae O139 strain MO10 as well as variant V. cholerae O1 El Tor strain NM06-058. Of the three most active substances, compound 53760866 showed lowest half-maximal cytotoxicity in a eukaryotic cell viability assay and was characterized further. Compound 53760866 caused reduction in cholera toxin secretion and expression of TcpA in vitro. The in vitro virulence attenuation corroborated well in a suckling mouse model in vivo, which showed reduction of colonization by V. cholerae NM06-058 when co-administered with 53760866. The screening method and the compounds may lead to new preventive strategies for cholera by reducing the pathogenicity of V. cholerae .

  6. Immunizing Canada geese against avian cholera

    Science.gov (United States)

    Price, J.I.

    1985-01-01

    A small flock of captive giant Canada geese were vaccinated with the experimental bac- terin in Nebraska to test its efficacy under field conditions. Only 2 of 157 vaccinates died from avian cholera during an annual spring die-off.

  7. Granulocytes of sea anemone Actinia equina (Linnaeus, 1758 body fluid contain and release cytolysins forming plaques of lysis

    Directory of Open Access Journals (Sweden)

    MG Parisi

    2014-01-01

    Full Text Available The Cnidaria phylum includes organisms that are among the most poisonous animals. The exact composition of cnidarian bioactive molecules is not known in detail, but little is known on the cells that produce the toxins. Here we have shown that the presence of cytolysins is not exclusive of nematocysts. A plaque-forming assay was carried out with cell populations extracted from the percoled body fluid showed for the first time that anthozoan granulocytes are able to form plaque of lysis. We have partitioned the total population of free cells into three distinct discrete bands by discontinuous Percoll gradient, and we have identified six small different types cells: morular granulocytes; cells with large or small peripherical granules, granulocytes with irregular shape containing blue and red granules, cells showing one fine red granule of uniform size and, finally, cells with elongated shape and small dispersed granules. Cell lysate of each cellular band resulted cytolytic toward different erythrocytes types. SDS page analysis of the lysate cell fraction showed a predominant of 20 kDa that corresponds to the weight of the cytolytic equinatoxin. The nature of equinatoxins-related activity was demonstrated by inhibition experiments using bovine sphingomyelin.

  8. Re-emergence of Cholera Vaccine.

    Science.gov (United States)

    Berger; Shapiro

    1997-06-01

    Although epidemic cholera was first described in 1817, the disease probably has been common in the Indian subcontinent since ancient times.1 Until recently, a single bacterial type (Vibrio cholerae 01) has been responsible for each of the seven recorded cholera pandemics. The current epidemic began in Celebes (Sulawesi), Indonesia, in 1961, and is currently raging through all continents.2 During the 1990s, over 1 million cholera cases have been reported from Latin America, 2000 from Ukraine and the Russian Republic during 1994 alone (GIDEON computer software, C.Y. Informatics, Ramat Hasharon, Israel). Of the 208,755 cases of cholera (5034 fatal) officially reported to the World Health Organization in 1995,3 41.1% were from Latin America, 34.0% from Africa, 24.4% from Asia, and 0.5% from Europe and Oceania. Interest in our own country of Israel stems from the popularity of tourism (over 1 million travelers exit Israel yearly) and the presence of disease in neighboring areas. Following an epidemic of 397 cases in Jerusalem during 1970, periodic outbreaks have occurred in Gaza, Judea and Samaria.4 Three tourists returned with the infection to Israel during the 1980s, all from Egypt (which officially claims to have no cholera).5 Despite universal interest in this ancient disease, medical science has long been frustrated in its search for an effective vaccine. The most important 'vaccine' against cholera is common sense, and consists of intelligent eating and drinking while in endemic areas. For example, local raw fish (ceviche) is a common source of the disease in Latin America, while shellfish (particularly oysters) are often implicated along the American Gulf Coast. Virtually all forms of water purification are effective against Vibrio cholerae. Although antibiotic prophylaxis might be considered in some circumstances (doxycycline; or a quinolone in areas of tetracycline resistance), it is not routinely advocated.

  9. FOWL CHOLERA IN A BREEDER FLOCK

    Directory of Open Access Journals (Sweden)

    Z. Parveen, A. A. Nasir, K.Tasneem and A. Shah

    2003-12-01

    Full Text Available During January, 2003 Pasteurella multocida the causative agent of fowl cholera was isolated from a breeder flock in Lahore District. The age of the flock was 245 days. Increased mortality, swollen wattles and lameness were the clinical findings present in almost all the affected birds, while gross lesions were typical of fowl cholera. To prove the virulence of the organism, mice and six-week old cockerals were infected and P. multocida was reisolated.

  10. Deciphering the origin of the 2012 cholera epidemic in Guinea by integrating epidemiological and molecular analyses.

    Directory of Open Access Journals (Sweden)

    Stanislas Rebaudet

    2014-06-01

    Full Text Available Cholera is typically considered endemic in West Africa, especially in the Republic of Guinea. However, a three-year lull period was observed from 2009 to 2011, before a new epidemic struck the country in 2012, which was officially responsible for 7,350 suspected cases and 133 deaths. To determine whether cholera re-emerged from the aquatic environment or was rather imported due to human migration, a comprehensive epidemiological and molecular survey was conducted. A spatiotemporal analysis of the national case databases established Kaback Island, located off the southern coast of Guinea, as the initial focus of the epidemic in early February. According to the field investigations, the index case was found to be a fisherman who had recently arrived from a coastal district of neighboring Sierra Leone, where a cholera outbreak had recently occurred. MLVA-based genotype mapping of 38 clinical Vibrio cholerae O1 El Tor isolates sampled throughout the epidemic demonstrated a progressive genetic diversification of the strains from a single genotype isolated on Kaback Island in February, which correlated with spatial epidemic spread. Whole-genome sequencing characterized this strain as an "atypical" El Tor variant. Furthermore, genome-wide SNP-based phylogeny analysis grouped the Guinean strain into a new clade of the third wave of the seventh pandemic, distinct from previously analyzed African strains and directly related to a Bangladeshi isolate. Overall, these results highly suggest that the Guinean 2012 epidemic was caused by a V. cholerae clone that was likely imported from Sierra Leone by an infected individual. These results indicate the importance of promoting the cross-border identification and surveillance of mobile and vulnerable populations, including fishermen, to prevent, detect and control future epidemics in the region. Comprehensive epidemiological investigations should be expanded to better understand cholera dynamics and improve

  11. Cholera: ancient scourge on the rise. WHO announces global plan for cholera control. (25 April 1991).

    Science.gov (United States)

    1991-04-01

    Vibrio cholerae spreads quickly via contaminated water and food, especially in areas with a poor health and sanitation infrastructure. Its enterotoxin induces vomiting and huge amounts of watery diarrhea leading to severe dehydration. 80-90% of cholera victims during an epidemic can use oral rehydration salts. A cholera epidemic is now spreading through Latin America threatening 90-120 million people (started in January 1991), particularly those in urban slums and rural/mountainous areas. As of mid April 1991, there were more than 177,000 new reported cases in 12 countries and 78% of these cases and more than 1200 deaths were limited to 5 countries: Brazil, Chile, Colombia, Ecuador, and Peru, WHO's Global Cholera Control Task Force coordinates global cholera control efforts to prevent deaths in the short term and to support infrastructure development in the long term. Its members are specialists in disease surveillance, case management, water and sanitation, food safety, emergency intervention, and information and education. WHO's Director General is asking for the support of the international community in cholera control activities. These activities' costs are considerable. For example, Peru needs about US$ 60 million in 1992 to fulfill only the most immediate demands of rehabilitation and reconstruction of the infrastructure. Costs of infrastructure capital throughout Latin America is almost US$ 5 thousand million/year over the next 10 years. It is indeed an effective infrastructure which ultimately prevents cholera. Cholera is evidence of inadequate development, so to fight it, we must also fight underdevelopment and poverty.

  12. 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

  13. Cholera toxin-B (ctxB) antigen expressing Salmonella Typhimurium polyvalent vaccine exerts protective immune response against Vibrio cholerae infection.

    Science.gov (United States)

    Vishwakarma, Vikalp; Sahoo, Sushree Sangita; Das, Susmita; Ray, Shilpa; Hardt, Wolf-Dietrich; Suar, Mrutyunjay

    2015-04-08

    Live attenuated vaccines are cost effective approach for preventing a broad range of infectious diseases, and thus are of great interest. However, immune-defects can predispose the patient to infections by the vaccine candidate itself. So far, few live vaccine candidates have been designed specifically for immune compromised individuals. Recently, we reported a new Salmonella Typhimurium Z234-vaccine strain (Periaswamy et al., PLoS ONE 2012;7:e45433), which was specifically attenuated in the NADPH-oxidase deficient host. In the present study, the Z234-vaccine strain was further engineered to express heterologous antigen (Vibrio cholerae toxin antigen subunit-B, i.e. CtxB) with the intention of creating a vector for simultaneous protection against Cholera and Salmonellosis. The primary aim of this study was to ensure the expression of CtxB antigen by the recombinant vaccine strain Z234-pMS101. The antigen CtxB was expressed through Z234 as a fusion protein with N-terminal signal sequence of Salmonella outer protein (SopE), an effector protein from Salmonella under the control of SopE promoter. The CtxB-expressing plasmid construct pMS101 (pM968-pSopE-ctxB) was found to be stable both in vitro and in vivo. In an oral mouse infection model, the vaccine strain Z234-pMS101 efficiently colonized the host gut. The extent of protection was confirmed after challenging the immunized hosts with live V. cholerae. Vaccinated mice showed reduced gut colonization by V. cholerae. Further assessment of immunological parameters supported the possibility of conferring effective immune response by Z234-pMS101 vaccine strain. Overall, the Z234-pMS101 vaccine strain showed potential as a promising polyvalent vaccine candidate to protect against S. Typhimurium and V. cholerae infection simultaneously.

  14. 5-hydroxytryptamine release into human jejunum by cholera toxin.

    OpenAIRE

    Bearcroft, C P; Perrett, D.; Farthing, M J

    1996-01-01

    BACKGROUND: Cholera toxin produces intestinal secretion by activation of the adenylate cyclase complex. However animal studies have shown 5-hydroxytryptamine may be released after exposure to cholera toxin, and thereby contribute to the secretory state. AIM: To determine whether cholera toxin releases 5-hydroxytryptamine in human jejunum. SUBJECTS: Seven male subjects were given a subclinical dose of cholera toxin in a paired, controlled, randomised, double blind study. METHODS: A closed 10 c...

  15. Cholera risk factors, Papua New Guinea, 2010

    Directory of Open Access Journals (Sweden)

    Rosewell Alexander

    2012-11-01

    Full Text Available Abstract Background Cholera is newly emergent in Papua New Guinea but may soon become endemic. Identifying the risk factors for cholera provides evidence for targeted prevention and control measures. Methods We conducted a hospital-based case–control study to identify cholera risk factors. Using stool culture as the standard, we evaluated a cholera point of care test in the field. Results 176 participants were recruited: 54 cases and 122 controls. Independent risk factors for cholera were: being over 20 years of age (aOR 2.5; 95%CI 1.1, 5.4, defecating in the open air (or river (aOR 4.5; 95% CI 1.4, 14.4 and knowing someone who travelled to a cholera affected area (aOR 4.1; 95%CI 1.6, 10.7; while the availability of soap for handwashing at home was protective (aOR 0.41; 95%CI 0.19, 0.87. Those reporting access to a piped water distribution system in the home were twice as likely to report the availability of soap for handwashing. The sensitivity and specificity of the rapid test were 72% (95% CI 47–90 and 71% (95%CI 44–90%. Conclusions Improving population access to the piped water distribution system and sanitation will likely reduce transmission by enabling enhanced hygiene and limiting the contamination of water sources. The One step V. cholerae O1/O139 Antigen Test is of limited utility for clinical decision making in a hospital setting with access to traditional laboratory methods. Settlement dwellers and mobile populations of all age groups should be targeted for interventions in Papua New Guinea.

  16. Avian cholera in Nebraska's Rainwater Basin

    Science.gov (United States)

    Windingstad, R.M.; Hurt, J.J.; Trout, A.K.; Cary, J.

    1984-01-01

    The first report of avian cholera in North America occurred in northwestern Texas in winter 1944 (Quortrup et al. 1946). In 1975, mortality from avian cholera occurred for the first time in waterfowl in the Rainwater Basin of Nebraska when an estimated 25,000 birds died (Zinkl et al. 1977). Avian cholera has continued to cause mortality in wild birds in specific areas of the Basin each spring since. Losses of waterfowl from avian cholera continue to be much greater in some of the wetlands in the western part of the Basin than in the east. Several wetlands in the west have consistently higher mortality and are most often the wetlands where initial mortality is noticed each spring (Figure 1). The establishment of this disease in Nebraska is of considerable concern because of the importance of the Rainwater Basin as a spring staging area for waterfowl migrating to their breeding grounds. The wetlands in this area are on a major migration route used by an estimated 5 to 9 million ducks and several hundred thousand geese. A large portion of the western mid-continental greater white-fronted goose (Anser albifrons) population stage in the Basin each spring. Occasionally, whooping cranes (Grus americana) use these wetlands during migration, and lesser sandhill cranes (Grus canadensis) staging on the nearby Platte River sometimes use wetlands where avian cholera occurs (Anonymous 1981). Our objectives were to determine whether certain water quality variables in the Rainwater Basin differed between areas of high and low avian cholera incidence. These results would then be used for laboratory studies involving the survivability of Pasteurella multocida, the causative bacterium of avian cholera. Those studies will be reported elsewhere.

  17. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vibrio cholerae serological reagents. 866.3930... cholerae serological reagents. (a) Identification. Vibrio cholerae serological reagents are devices that are used in the agglutination (an antigen-antibody clumping reaction) test to identify Vibrio...

  18. Whole-Genome Sequences of 26 Vibrio cholerae Isolates

    Science.gov (United States)

    Watve, Samit S.; Chande, Aroon T.; Rishishwar, Lavanya; Jordan, I. King

    2016-01-01

    The human pathogen Vibrio cholerae employs several adaptive mechanisms for environmental persistence, including natural transformation and type VI secretion, creating a reservoir for the spread of disease. Here, we report whole-genome sequences of 26 diverse V. cholerae isolates, significantly increasing the sequence diversity of publicly available V. cholerae genomes. PMID:28007852

  19. Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

    Directory of Open Access Journals (Sweden)

    Seon Young Choi

    2016-03-01

    Full Text Available An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997. Nontoxigenic (CTX− V. cholerae El Tor dominated toxigenic (CTX+ strains (2001 to 2003, but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX−V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity.

  20. Fucosylation and protein glycosylation create functional receptors for cholera toxin

    Science.gov (United States)

    Wands, Amberlyn M; Fujita, Akiko; McCombs, Janet E; Cervin, Jakob; Dedic, Benjamin; Rodriguez, Andrea C; Nischan, Nicole; Bond, Michelle R; Mettlen, Marcel; Trudgian, David C; Lemoff, Andrew; Quiding-Järbrink, Marianne; Gustavsson, Bengt; Steentoft, Catharina; Clausen, Henrik; Mirzaei, Hamid; Teneberg, Susann; Yrlid, Ulf; Kohler, Jennifer J

    2015-01-01

    Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we report that CTB binds cell surface glycoproteins. Relative contributions of gangliosides and glycoproteins to CTB binding depend on cell type, and CTB binds primarily to glycoproteins in colonic epithelial cell lines. Using a metabolically incorporated photocrosslinking sugar, we identified one CTB-binding glycoprotein and demonstrated that the glycan portion of the molecule, not the protein, provides the CTB interaction motif. We further show that fucosylated structures promote CTB entry into a colonic epithelial cell line and subsequent host cell intoxication. CTB-binding fucosylated glycoproteins are present in normal human intestinal epithelia and could play a role in cholera. DOI: http://dx.doi.org/10.7554/eLife.09545.001 PMID:26512888

  1. A novel peptidoglycan binding protein crucial for PBP1A-mediated cell wall biogenesis in Vibrio cholerae.

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    Tobias Dörr

    2014-06-01

    Full Text Available The bacterial cell wall, which is comprised of a mesh of polysaccharide strands crosslinked via peptide bridges (peptidoglycan, PG, is critical for maintenance of cell shape and survival. PG assembly is mediated by a variety of Penicillin Binding Proteins (PBP whose fundamental activities have been characterized in great detail; however, there is limited knowledge of the factors that modulate their activities in different environments or growth phases. In Vibrio cholerae, the cause of cholera, PG synthesis during the transition into stationary phase is primarily mediated by the bifunctional enzyme PBP1A. Here, we screened an ordered V. cholerae transposon library for mutants that are sensitive to growth inhibition by non-canonical D-amino acids (DAA, which prevent growth and maintenance of cell shape in PBP1A-deficient V. cholerae. In addition to PBP1A and its lipoprotein activator LpoA, we found that CsiV, a small periplasmic protein with no previously described function, is essential for growth in the presence of DAA. Deletion of csiV, like deletion of lpoA or the PBP1A-encoding gene mrcA, causes cells to lose their rod shape in the presence of DAA or the beta-lactam antibiotic cefsulodin, and all three mutations are synthetically lethal with deletion of mrcB, which encodes PBP1B, V. cholerae's second key bifunctional PBP. CsiV interacts with LpoA and PG but apparently not with PBP1A, supporting the hypothesis that CsiV promotes LpoA's role as an activator of PBP1A, and thereby modulates V. cholerae PG biogenesis. Finally, the requirement for CsiV in PBP1A-mediated growth of V. cholerae can be overcome either by augmenting PG synthesis or by reducing PG degradation, thereby highlighting the importance of balancing these two processes for bacterial survival.

  2. Independent control of replication initiation of the two Vibrio cholerae chromosomes by DnaA and RctB

    DEFF Research Database (Denmark)

    Duigou, Stephane; Knudsen, Kristine Groth; Skovgaard, Ole

    2006-01-01

    Although the two Vibrio cholerae chromosomes initiate replication in a coordinated fashion, we show here that each chromosome appears to have a specific replication initiator. DnaA overproduction promoted overinitiation of chromosome I and not chromosome II. In contrast, overproduction of Rct...

  3. Cholera in Thomas Mann's Death in Venice.

    Science.gov (United States)

    Rütten, Thomas

    2009-01-01

    The article sets the cholera motif in Thomas Mann's famous novella Death in Venice against the historical context from which it partially originates. It is shown that this motif, while undoubtedly appropriated to serve Mann's own poetic ends, has a solid grounding in historical and autobiographical fact, thus blurring the boundaries between fact and fiction. The article illustrates the verifiable events of the outbreak of the Venetian cholera epidemic in May 1911, which Mann partly witnessed himself, during a holiday trip to Brioni and Venice, and partly heard and read about. It is established that Thomas Mann's account of the cholera in Venice in his novella is characterised by a rare and almost preternatural insightfulness into an otherwise murky affair that was marked by rumours, speculations and denials.

  4. Vibrio cholerae as a predator: lessons from evolutionary principles

    Directory of Open Access Journals (Sweden)

    Stefan ePukatzki

    2013-12-01

    Full Text Available Diarrheal diseases are the second-most common cause of death among children under the age of five worldwide. Cholera alone, caused by the marine bacterium Vibrio cholerae, is responsible for several million cases and over 120,000 deaths annually. When contaminated water is ingested, V. cholerae passes through the gastric acid barrier, penetrates the mucin layer of the small intestine, and adheres to the underlying epithelial lining. V. cholerae multiplies rapidly, secretes cholera toxin, and exits the human host in vast numbers during diarrheal purges. How V. cholerae rapidly reaches such high numbers during each purge is not clearly understood. We propose that V. cholerae employs its bactericidal type VI secretion system to engage in intraspecies and intraguild predation for nutrient acquisition to support rapid growth and multiplication.

  5. Population-Level Effect of Cholera Vaccine on Displaced Populations, South Sudan, 2014.

    Science.gov (United States)

    Azman, Andrew S; Rumunu, John; Abubakar, Abdinasir; West, Haley; Ciglenecki, Iza; Helderman, Trina; Wamala, Joseph Francis; Vázquez, Olimpia de la Rosa; Perea, William; Sack, David A; Legros, Dominique; Martin, Stephen; Lessler, Justin; Luquero, Francisco J

    2016-06-01

    Following mass population displacements in South Sudan, preventive cholera vaccination campaigns were conducted in displaced persons camps before a 2014 cholera outbreak. We compare cholera transmission in vaccinated and unvaccinated areas and show vaccination likely halted transmission within vaccinated areas, illustrating the potential for oral cholera vaccine to stop cholera transmission in vulnerable populations.

  6. Population-Level Effect of Cholera Vaccine on Displaced Populations, South Sudan, 2014

    OpenAIRE

    Azman, AS; Rumunu, J; Abubakar, A.; West, H.; Ciglenecki, I; Helderman, T; Wamala, JF; Vázquez, OR; W Perea; Sack, DA; Legros, D; Martin, S; Lessler, J; Luquero, FJ

    2016-01-01

    Following mass population displacements in South Sudan, preventive cholera vaccination campaigns were conducted in displaced persons camps before a 2014 cholera outbreak. We compare cholera transmission in vaccinated and unvaccinated areas and show vaccination likely halted transmission within vaccinated areas, illustrating the potential for oral cholera vaccine to stop cholera transmission in vulnerable populations.

  7. Rapid effects of a protective O-polysaccharide-specific monoclonal IgA on Vibrio cholerae agglutination, motility, and surface morphology.

    Science.gov (United States)

    Levinson, Kara J; De Jesus, Magdia; Mantis, Nicholas J

    2015-04-01

    2D6 is a dimeric monoclonal immunoglobulin A (IgA) specific for the nonreducing terminal residue of Ogawa O-polysaccharide (OPS) of Vibrio cholerae. It was previously demonstrated that 2D6 IgA is sufficient to passively protect suckling mice from oral challenge with virulent V. cholerae O395. In this study, we sought to define the mechanism by which 2D6 IgA antibody protects the intestinal epithelium from V. cholerae infection. In a mouse ligated-ileal-loop assay, 2D6 IgA promoted V. cholerae agglutination in the intestinal lumen and limited the ability of the bacteria to associate with the epithelium, particularly within the crypt regions. In vitro fluorescence digital video microscopy analysis of antibody-treated V. cholerae in liquid medium revealed that 2D6 IgA not only induced the rapid (5- to 10-min) onset of agglutination but was an equally potent inhibitor of bacterial motility. Scanning electron microscopy showed that 2D6 IgA promoted flagellum-flagellum cross-linking, as well as flagellar entanglement with bacterial bodies, suggesting that motility arrest may be a consequence of flagellar tethering. However, monovalent 2D6 Fab fragments also inhibited V. cholerae motility, demonstrating that antibody-mediated agglutination and motility arrest are separate phenomena. While 2D6 IgA is neither bactericidal nor bacteriostatic, exposure of V. cholerae to 2D6 IgA (or Fab fragments) resulted in a 5-fold increase in surface-associated blebs, as well an onset of a wrinkled surface morphotype. We propose that the protective immunity conferred by 2D6 IgA is the result of multifactorial effects on V. cholerae, including agglutination, motility arrest, and possibly outer membrane stress.

  8. Evidence that a non-O1 Vibrio cholerae produces enterotoxin that is similar but not identical to cholera enterotoxin.

    OpenAIRE

    Yamamoto, K.; Takeda, Y.; Miwatani, T; Craig, J. P.

    1983-01-01

    Cholera-like enterotoxin produced by a non-O1 strain of Vibrio cholerae, S7 (S7 enterotoxin), isolated from human diarrheal stool, was purified, and its physicochemical, biological, and immunological properties were compared with those of cholera enterotoxin from V. cholerae O1 569B (CT) and an enterotoxin produced by another non-O1 V. cholerae (E8498 enterotoxin) reported previously (Yamamoto et al., Infect. Immun. 39:1128-1135, 1983). The purified S7 enterotoxin had physicochemical properti...

  9. Spreading of Cholera through Surface Water

    Science.gov (United States)

    Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2009-12-01

    Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i

  10. Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola

    Science.gov (United States)

    Azarian, Taj; Ali, Afsar; Johnson, Judith A.; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J.; Farmerie, William; Rashid, Mohammad H.; Sinha-Ray, Shrestha; Alam, Meer T.; Morris, J. Glenn; Salemi, Marco

    2016-01-01

    Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6th and 7th pandemic lineages, and diverge from “modern” cholera strains around 1548 C.E. [95% HPD: 1532–1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ. PMID:27786291

  11. Vibrio cholerae Serogroup O139: Isolation from Cholera Patients and Asymptomatic Household Family Members in Bangladesh between 2013 and 2014.

    Directory of Open Access Journals (Sweden)

    Fahima Chowdhury

    2015-11-01

    Full Text Available Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere.Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup.Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups.These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs.

  12. Detection of Vibrio cholerae and Acanthamoeba species from same natural water samples collected from different cholera endemic areas in Sudan

    Directory of Open Access Journals (Sweden)

    Saeed Amir

    2011-04-01

    Full Text Available Abstract Background Vibrio cholerae O1 and V. cholerae O139 infect humans, causing the diarrheal and waterborne disease cholera, which is a worldwide health problem. V. cholerae and the free-living amoebae Acanthamoeba species are present in aquatic environments, including drinking water and it has shown that Acanthamoebae support bacterial growth and survival. Recently it has shown that Acanthamoeba species enhanced growth and survival of V. cholerae O1 and O139. Water samples from different cholera endemic areas in Sudan were collected with the aim to detect both V. cholerae and Acanthamoeba species from same natural water samples by polymerase chain reaction (PCR. Findings For the first time both V. cholerae and Acanthamoeba species were detected in same natural water samples collected from different cholera endemic areas in Sudan. 89% of detected V. cholerae was found with Acanthamoeba in same water samples. Conclusions The current findings disclose Acanthamoedae as a biological factor enhancing survival of V. cholerae in nature.

  13. Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola.

    Science.gov (United States)

    Azarian, Taj; Ali, Afsar; Johnson, Judith A; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J; Farmerie, William; Rashid, Mohammad H; Sinha-Ray, Shrestha; Alam, Meer T; Morris, J Glenn; Salemi, Marco

    2016-10-27

    Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6(th) and 7(th) pandemic lineages, and diverge from "modern" cholera strains around 1548 C.E. [95% HPD: 1532-1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ.

  14. Vibrio cholerae Serogroup O139: Isolation from Cholera Patients and Asymptomatic Household Family Members in Bangladesh between 2013 and 2014

    Science.gov (United States)

    Chowdhury, Fahima; Mather, Alison E.; Begum, Yasmin Ara; Asaduzzaman, Muhammad; Baby, Nabilah; Sharmin, Salma; Biswas, Rajib; Ikhtear Uddin, Muhammad; LaRocque, Regina C.; Harris, Jason B.; Calderwood, Stephen B.; Ryan, Edward T.; Clemens, John D.; Thomson, Nicholas R.; Qadri, Firdausi

    2015-01-01

    Background Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere. Methods Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup. Findings Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups. Conclusion These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs. PMID:26562418

  15. Antibody-secreting cell responses after Vibrio cholerae O1 infection and oral cholera vaccination in adults in Bangladesh.

    Science.gov (United States)

    Rahman, Atiqur; Rashu, Rasheduzzaman; Bhuiyan, Taufiqur Rahman; Chowdhury, Fahima; Khan, Ashraful Islam; Islam, Kamrul; LaRocque, Regina C; Ryan, Edward T; Wrammert, Jens; Calderwood, Stephen B; Qadri, Firdausi; Harris, Jason B

    2013-10-01

    Infection with Vibrio cholerae and oral cholera vaccines (OCVs) induce transient circulating plasmablast responses that peak within approximately 7 days after infection or vaccination. We previously demonstrated that plasmablast responses strongly correlate with subsequent levels of V. cholerae-specific duodenal antibodies up to 6 months after V. cholerae infection. Hence, plasmablast responses provide an early window into the immunologic memory at the mucosal surface. In this study, we characterized plasmablast responses following V. cholerae infection using a flow cytometrically defined population and compared V. cholerae-specific responses in adult patients with V. cholerae O1 infection and vaccinees who received the OCV Dukoral (Crucell Vaccines Canada). Among flow cytometrically sorted populations of gut-homing plasmablasts, almost 50% of the cells recognized either cholera toxin B subunit (CtxB) or V. cholerae O1 lipopolysaccharide (LPS). Using a traditional enzyme-linked immunosorbent spot assay (ELISPOT), we found that infection with V. cholerae O1 and OCVs induce similar responses to the protein antigen CtxB, but responses to LPS were diminished after OCV compared to those after natural V. cholerae infection. A second dose of OCV on day 14 failed to boost circulating V. cholerae-specific plasmablast responses in Bangladeshi adults. Our results differ from those in studies from areas where cholera is not endemic, in which a second vaccination on day 14 significantly boosts plasmablast responses. Given these results, it is likely that the optimal boosting strategies for OCVs differ significantly between areas where V. cholerae infection is endemic and those where it is not.

  16. Swedish isolates of Vibrio cholerae enhance their survival when interacted intracellularly with Acanthamoeba castellanii

    Directory of Open Access Journals (Sweden)

    Salah Shanan

    2016-04-01

    Full Text Available Vibrio cholerae is a Gram-negative bacterium that occurs naturally in aquatic environment. Only V. cholerae O1 and V. cholerae O139 produce cholera toxin and cause cholera, other serogroups can cause gastroenteritis, open wounds infection, and septicaemia. V. cholerae O1 and V. cholerae O139 grow and survive inside Acanthamoeba castellanii. The aim of this study is to investigate the interactions of the Swedish clinical isolates V. cholerae O3, V. cholerae O4, V. cholerae O5, V. cholerae O11, and V. cholerae O160 with A. castellanii. The interaction between A. castellanii and V. cholerae strains was studied by means of amoeba cell counts, viable counts of the bacteria in the absence or presence of amoebae, and of the intracellularly growing bacteria, visualised by electron microscopy. These results show that all V. cholerae can grow and survive outside and inside the amoebae, disclosing that V. cholerae O3, V. cholerae O4, V. cholerae O5, V. cholerae O11, and V. cholerae O160 all can be considered as facultative intracellular bacteria.

  17. Swedish isolates of Vibrio cholerae enhance their survival when interacted intracellularly with Acanthamoeba castellanii.

    Science.gov (United States)

    Shanan, Salah; Bayoumi, Magdi; Saeed, Amir; Sandström, Gunnar; Abd, Hadi

    2016-01-01

    Vibrio cholerae is a Gram-negative bacterium that occurs naturally in aquatic environment. Only V. cholerae O1 and V. cholerae O139 produce cholera toxin and cause cholera, other serogroups can cause gastroenteritis, open wounds infection, and septicaemia. V. cholerae O1 and V. cholerae O139 grow and survive inside Acanthamoeba castellanii. The aim of this study is to investigate the interactions of the Swedish clinical isolates V. cholerae O3, V. cholerae O4, V. cholerae O5, V. cholerae O11, and V. cholerae O160 with A. castellanii. The interaction between A. castellanii and V. cholerae strains was studied by means of amoeba cell counts, viable counts of the bacteria in the absence or presence of amoebae, and of the intracellularly growing bacteria, visualised by electron microscopy. These results show that all V. cholerae can grow and survive outside and inside the amoebae, disclosing that V. cholerae O3, V. cholerae O4, V. cholerae O5, V. cholerae O11, and V. cholerae O160 all can be considered as facultative intracellular bacteria.

  18. 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).

  19. Invasive Vibrio cholerae Infection Following Burn Injury

    Science.gov (United States)

    2008-06-01

    as asymptomatic col- onization, otitis, gastroenteritis , soft-tissue infection, sepsis, or even cerebritis. In contrast, epidemic V. cholerae (O-1 or...review of the available literature is presented in Table 1. CONCLUSION Infection with invasive Vibrio species bacteria (e.g. Vibrio vulnificus

  20. Maladi Kolera 2 PSA (:30) (Cholera 2)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about cholera prevention and food preparation tips you can use to prevent the spread of disease. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  1. Maladi Kolera 1 PSA (:30) (Cholera 1)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about cholera symptoms and ways you can prevent the spread of disease. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  2. EFFECT OF AGGREGATION ON VIBRIO CHOLERAE INACTIVATION

    Science.gov (United States)

    Extensive research has shown that microorganisms exhibit increased resistance due to clumping, aggregation, particle association, or modification of antecedent growth conditions. During the course of investigating a major water-borne Vibrio cholerae outbreak in Peru, U.S. EPA inv...

  3. Preventing Maritime Transfer of Toxigenic Vibrio cholerae

    Science.gov (United States)

    Slaten, Douglas D.; Marano, Nina; Tappero, Jordan W.; Wellman, Michael; Albert, Ryan J.; Hill, Vincent R.; Espey, David; Handzel, Thomas; Henry, Ariel; Tauxe, Robert V.

    2012-01-01

    Organisms, including Vibrio cholerae, can be transferred between harbors in the ballast water of ships. Zones in the Caribbean region where distance from shore and water depth meet International Maritime Organization guidelines for ballast water exchange are extremely limited. Use of ballast water treatment systems could mitigate the risk for organism transfer. PMID:23017338

  4. A Natural Vaccine Candidate Strain Against Cholera

    Institute of Scientific and Technical Information of China (English)

    LIUYAN-QING; QIGUO-MING; 等

    1995-01-01

    El Tor Vibrio cholerae(EVC)strains may be classified into two kinds-epidemigenic(EEVC)strains and non-epidemigenic(NEEVC)strains-based on a phage-biotyping system.A large number of EEVC strains have been screened for toxigenic and putative colonization attributes.One such naturally occurring strain(designated IEM101)has been found which is devoid of genes encoding cholera toxin(CT),accessory cholera enterotoxin(ACE),zonula occludens toxin(ZOT),but possesses RS1 sequences and toixn-coregulated pilus A gene(tcpA)although tcpA is poorly expressed.It expresses type B pili but does not posses type C pili.It is an El Tor Ogawa strain and does not cause fluid accumulation in rabbit ileal loop tests.Active immunization of rabbits with strain IEM101 elicited good protection against challenge with virulent strains of V.cholerae Ol.Oral administration cased no side effects in 15 human volunteers.colonized the gut for four to ten days and elicited good immune responses.

  5. Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

    Energy Technology Data Exchange (ETDEWEB)

    Brettin, Thomas S [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Han, Cliff S [Los Alamos National Laboratory; Munik, A C [Los Alamos National Laboratory; Chertkov, Olga [Los Alamos National Laboratory; Meincke, Linda [Los Alamos National Laboratory; Saunders, Elizabeth [Los Alamos National Laboratory; Choi, Seon Y [SEOUL NATL. UNIV.; Haley, Bradd J [U. MARYLAND; Taviani, Elisa [U. MARYLAND; Jeon, Yoon - Seong [INTL. VACCINE INST. SEOUL; Kim, Dong Wook [INTL. VACCINE INST. SEOUL; Lee, Jae - Hak [SEOUL NATL. UNIV.; Walters, Ronald A [PNNL; Hug, Anwar [NATL. INST. CHOLERIC ENTERIC DIS.; Colwell, Rita R [U. MARYLAND

    2009-01-01

    Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated from a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to

  6. Sanitation in the time of cholera.

    Science.gov (United States)

    Misch, A

    1991-01-01

    Cholera, identified by violent diarrhea, cramps, vomiting, and dehydration, is spreading through Peru into Colombia, Ecuador, Child, and Brazil. Water contaminated with Vibrio cholerae is used for washing food and/or drinking thereby transmitting the disease. PAHO estimates 6 million people in South America may get cholera within the next 3 years. This cholera epidemic is the result of unsanitary conditions in which the urban poor in South America live. In fact, in Lima, Peru, 40% of the people do not have potable, piped water available. These individuals fetch their water from far away taps and private vendors both of which are not necessarily safe. In addition, 40% do not have access to a sewage system. Further, 80% of sick people in developing countries have a water related illness, be it transmitted by contaminated water or by insects and snails that reproduce in the water. Diarrhea is the most deadly of these conditions. Indeed every year 10-20 million children die from the effects of diarrhea which include malnutrition, dehydration, and shock. Yet 940 million people in developing countries have no access to safe water and 1.7 billion do not have a sanitary means of disposing of human wastes, despite the fact that the UN decreed the 1980s the International Drinking Water Supply and Sanitation Decade. Nevertheless UNICEF efforts did bring communal taps, odorless latrines, and/or pour flush toilets to 1.2 billion people. These types of sanitation costs $20-25/person whereas conventional sewers cost $350/person. Low technology supplied water averages $30/person compared to $200/person for piped water. Peru has spent $43 million on emergency medical care for cholera victims which could have provided low cost clean water and sanitation for almost 800,000 poor.

  7. High Depth, Whole-Genome Sequencing of Cholera Isolates from Haiti and the Dominican Republic

    Science.gov (United States)

    2012-09-11

    Vibrio cholerae isolates from Haiti and the Dominican Republic and three additional V. cholerae isolates to a high depth of coverage (>2000x); four of...We used whole-genome approaches to sequence four Vibrio cholerae isolates from Haiti and the Dominican Republic and three additional V. cholerae ...during an epidemic. Keywords Whole-genome sequencing, Vibrio cholerae , Haitian cholera epidemic, Microbial evolution Background Following the

  8. Validation and characterization of a human volunteer challenge model for cholera by using frozen bacteria of the new Vibrio cholerae epidemic serotype, O139

    NARCIS (Netherlands)

    Cohen, MB; Giannella, RA; Losonsky, GA; Lang, DR; Parker, S; Hawkins, JA; Gunther, C; Schiff, GA

    1999-01-01

    Until recently, all epidemic strains of Vibrio cholerae were of the O1 serotype. Current epidemics have also been caused by a new serotype, Vibrio cholerae O139. Although the pathogenesis and clinical features of O139 cholera are similar to those of O1 cholera, immunity to serotype O1 does not confe

  9. Rugose atypical Vibrio cholerae O1 El Tor responsible for 2009 cholera outbreak in India.

    Science.gov (United States)

    Chowdhury, Goutam; Bhadra, Rupak K; Bag, Satyabrata; Pazhani, Gururaja P; Das, Bhabatosh; Basu, Pallabi; Nagamani, K; Nandy, Ranjan K; Mukhopadhyay, Asish K; Ramamurthy, Thandavarayan

    2016-10-01

    Vibrio cholerae causes cholera outbreaks in endemic regions where the water quality and sanitation facilities remain poor. Apart from biotype and serotype changes, V. cholerae undergoes phase variation, which results in the generation of two morphologically different variants termed smooth and rugose. In this study, 12 rugose (R-VC) and 6 smooth (S-VC) V. cholerae O1 Ogawa isolates were identified in a cholera outbreak that occurred in Hyderabad, India. Antimicrobial susceptibility results showed that all the isolates were resistant to ampicillin, furazolidone and nalidixic acid. In addition, R-VC isolates were resistant to ciprofloxacin (92 %), streptomycin (92 %), erythromycin (83 %), trimethoprim-sulfamethoxazole (75 %) and tetracycline (75 %). Based on the ctxB gene analysis, all the isolates were identified as El Tor variant with mutation in two positions of ctxB, similar to the classical biotype. The R-VC isolates specifically showed excessive biofilm formation and were comparatively less motile. In addition, the majority of these isolates (~83 %) displayed random mutations in the hapR gene, which encodes haemagglutinin protease regulatory protein. In the PFGE analysis, R-VC and S-VC were placed in distinct clusters but remained clonally related. In the ribotyping analysis, all the R-VC isolates exhibited R-III pattern, which is a prevailing type among the current El Tor isolates. A hapR deletion mutant generated using an S-VC isolate expressed rugose phenotype. To our knowledge, this is the first report on the association of rugose V. cholerae O1 in a large cholera outbreak with extended antimicrobial resistance and random mutations in the haemagglutinin protease regulatory protein encoding gene (hapR).

  10. Accessory cholera enterotoxin, Ace, from Vibrio cholerae: structure, unfolding, and virstatin binding.

    Science.gov (United States)

    Chatterjee, Tanaya; Mukherjee, Debadrita; Dey, Sucharita; Pal, Aritrika; Hoque, Kazi Mirajul; Chakrabarti, Pinak

    2011-04-12

    Vibrio cholerae accessory cholera enterotoxin (Ace) is the third toxin, along with cholera toxin (CT) and zonula occludens toxin (Zot), that causes the endemic disease cholera. Structural characterization of Ace has been restricted because of the limited production of this toxic protein by V. cholerae. We have cloned, overexpressed, and purified Ace from V. cholerae strain O395 in Escherichia coli to homogeneity and determined its biological activity. The unfolding of the purified protein was investigated using circular dichroism and intrinsic tryptophan fluorescence. Because Ace is predominantly a hydrophobic protein, the degree of exposure of hydrophobic regions was identified from the spectral changes of the environment-sensitive fluorescent probe 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) that quenches the fluorescence of tryptophan residues of Ace in a concentration-dependent manner. Results showed that bis-ANS binds one monomeric unit of Ace with a 1:1 stoichiometry and a K' of 0.72 μM. Ace exists as a dimer, with higher oligomeric forms appearing upon glutaraldehyde cross-linking. This study also reports the binding of virstatin, a small molecule that inhibits virulence regulation in V. cholerae, to Ace. The binding constant (K=9×10(4) M(-1)) and the standard free energy change (ΔG°=-12 kcal mol(-1)) of Ace-virstatin interaction have been evaluated by the fluorescence quenching method. The binding does not affect the oligomeric status of Ace. A cell viability assay of the antibacterial activity of Ace has been performed using various microbial strains. A homology model of Ace, consistent with the experimental results, has been constructed.

  11. Cholera toxin structure, gene regulation and pathophysiological and immunological aspects.

    Science.gov (United States)

    Sánchez, J; Holmgren, J

    2008-05-01

    Many notions regarding the function, structure and regulation of cholera toxin expression have remained essentially unaltered in the last 15 years. At the same time, recent findings have generated additional perspectives. For example, the cholera toxin genes are now known to be carried by a non-lytic bacteriophage, a previously unsuspected condition. Understanding of how the expression of cholera toxin genes is controlled by the bacterium at the molecular level has advanced significantly and relationships with cell-density-associated (quorum-sensing) responses have recently been discovered. Regarding the cell intoxication process, the mode of entry and intracellular transport of cholera toxin are becoming clearer. In the immunological field, the strong oral immunogenicity of the non-toxic B subunit of cholera toxin (CTB) has been exploited in the development of a now widely licensed oral cholera vaccine. Additionally, CTB has been shown to induce tolerance against co-administered (linked) foreign antigens in some autoimmune and allergic diseases.

  12. Expression and secretion of cholera toxin B subunit in lactobacilli.

    Science.gov (United States)

    Okuno, Takahiro; Kashige, Nobuhiro; Satho, Tomomitsu; Irie, Keiichi; Hiramatsu, Yukihiro; Sharmin, Tanjina; Fukumitsu, Yuki; Uyeda, Saori; Yamada, Seitaro; Harakuni, Tetsuya; Miyata, Takeshi; Arakawa, Takeshi; Imoto, Masumi; Toda, Akihisa; Nakashima, Yukihiko; Miake, Fumio

    2013-01-01

    Lactic acid bacteria (LAB) are used in various fields, including in food and medical supplies. There has been a great deal of research into vaccine development using LAB as carriers due to their "generally recognized as safe" status. Cholera is an infectious disease that causes diarrhea due to cholera toxin (CT) produced by Vibrio cholerae. The pentameric cholera toxin B (CTB) subunit has no toxicity, and is used as an antigen in cholera vaccines and as a delivery molecule in vaccines to various diseases. In this study, we generated recombinant LAB expressing and secreting CTB. Here, we first report that CTB expressed and secreted from LAB bound to GM1 ganglioside. The secreted CTB was purified, and its immunogenicity was determined by intranasal administration into mice. The results of the present study suggested that it may be useful as the basis of a new oral cholera vaccine combining LAB and CTB.

  13. Chemoproteomic profiling of host and pathogen enzymes active in cholera

    Science.gov (United States)

    Hatzios, Stavroula K.; Hubbard, Troy; Sasabe, Jumpei; Munera, Diana; Clark, Lars; Bachovchin, Daniel A.; Qadri, Firdausi; Ryan, Edward T.; Davis, Brigid M.; Weerapana, Eranthie; Waldor, Matthew K.

    2016-01-01

    Activity-based protein profiling (ABPP) is a chemoproteomic tool for detecting active enzymes in complex biological systems. We used ABPP to identify secreted bacterial and host serine hydrolases that are active in animals infected with the cholera pathogen Vibrio cholerae. Four V. cholerae proteases were consistently active in infected rabbits, and one, VC0157 (renamed IvaP), was also active in human cholera stool. Inactivation of IvaP influenced the activity of other secreted V. cholerae and rabbit enzymes in vivo, while genetic disruption of all four proteases increased the abundance and binding of an intestinal lectin—intelectin—to V. cholerae in infected rabbits. Intelectin also bound to other enteric bacterial pathogens, suggesting it may constitute a previously unrecognized mechanism of bacterial surveillance in the intestine that is inhibited by pathogen-secreted proteases. Our work demonstrates the power of activity-based proteomics to reveal host-pathogen enzymatic dialogue in an animal model of infection. PMID:26900865

  14. Cholera outbreaks caused by an altered Vibrio cholerae O1 El Tor biotype strain producing classical cholera toxin B in Vietnam in 2007 to 2008.

    Science.gov (United States)

    Nguyen, Binh Minh; Lee, Je Hee; Cuong, Ngo Tuan; Choi, Seon Young; Hien, Nguyen Tran; Anh, Dang Duc; Lee, Hye Ri; Ansaruzzaman, M; Endtz, Hubert P; Chun, Jongsik; Lopez, Anna Lena; Czerkinsky, Cecil; Clemens, John D; Kim, Dong Wook

    2009-05-01

    Vibrio cholerae O1 isolates collected during cholera outbreaks occurring from late 2007 to early 2008 in northern Vietnam were revealed to represent an altered strain containing the RS1 element followed by a CTX prophage harboring El Tor type rstR and classical ctxB on the large chromosome.

  15. Epidemiology of cholera outbreaks and socio-economic characteristics of the communities in the fishing villages of Uganda: 2011-2015

    Science.gov (United States)

    Ouedraogo, Issaka; Heyerdahl, Leonard; Komakech, Henry; Kagirita, Atek; Wood, Richard; Mhlanga, Raymond; Njanpop-Lafourcade, Berthe; Malimbo, Mugagga; Makumbi, Issa; Wandawa, Jennifer; Gessner, Bradford D.; Orach, Christopher Garimoi; Mengel, Martin A.

    2017-01-01

    Background The communities in fishing villages in the Great Lakes Region of Africa and particularly in Uganda experience recurrent cholera outbreaks that lead to considerable mortality and morbidity. We evaluated cholera epidemiology and population characteristics in the fishing villages of Uganda to better target prevention and control interventions of cholera and contribute to its elimination from those communities. Methodology/Principal findings We conducted a prospective study between 2011–15 in fishing villages in Uganda. We collected, reviewed and documented epidemiological and socioeconomic data for 10 cholera outbreaks that occurred in fishing communities located along the African Great Lakes and River Nile in Uganda. These outbreaks caused 1,827 suspected cholera cases and 43 deaths, with a Case-Fatality Ratio (CFR) of 2.4%. Though the communities in the fishing villages make up only 5–10% of the Ugandan population, they bear the biggest burden of cholera contributing 58% and 55% of all reported cases and deaths in Uganda during the study period. The CFR was significantly higher among males than females (3.2% vs. 1.3%, p = 0.02). The outbreaks were seasonal with most cases occurring during the months of April-May. Male children under age of 5 years, and 5–9 years had increased risk. Cholera was endemic in some villages with well-defined “hotspots”. Practices predisposing communities to cholera outbreaks included: the use of contaminated lake water, poor sanitation and hygiene. Additional factors were: ignorance, illiteracy, and poverty. Conclusions/Significance Cholera outbreaks were a major cause of morbidity and mortality among the fishing communities in Uganda. In addition to improvements in water, sanitation, and hygiene, oral cholera vaccines could play an important role in the prevention and control of these outbreaks, particularly when targeted to high-risk areas and populations. Promotion and facilitation of access to social services

  16. Crystallization and preliminary crystallographic analysis of an Enterococcus faecalis repressor protein, CylR2, involved in regulating cytolysin production through quorum-sensing

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Shuisong; McAteer, Kathleen; Bussiere, Dirksen E.; Kennedy, Michael A.

    2004-06-01

    CylR2 is one of the two regulatory proteins associated with the quorum-sensing-dependent synthesis of cytolysin for the common pathogen Enterococcus faecalis. The protein was expressed with a C-terminal 6-histidine tag and purified to homogeneity with a cobalt affinity column followed by another size exclusion column. Both native and SeMet proteins were crystallized. A complete X-ray diffraction data set from the native crystal was collected to 2.3 resolution. The crystal was tetragonal, belonging to space group P41/43, with unit-cell dimensions a=b=66.2 , c=40.9 and a=b=g=90. The asymmetric unit contained two molecules of CylR2.

  17. Crystallization and preliminary X-ray diffraction studies of θ-toxin (perfringolysin O), a pore-forming cytolysin of Clostridium perfringens

    Science.gov (United States)

    Sugahara, Mitsuaki; Sekino-Suzuki, Naoko; Ohno-Iwashita, Yoshiko; Miki, Kunio

    1996-10-01

    θ-Toxin (perfringolysin O), a cholesterol-binding, pore-forming cytolysin of Clostridium perfringens type A was crystallized by the vapor diffusion procedure using polyethyleneglycol 4000 and sodium chloride as precipitants in 2-(cyclohexylamino)ethanesulfonic acid (CHES) buffer at pH 9.5. The diffraction patterns of precession photographs indicated that the crystals belong to the orthorhombic system and the space group C222 1 with unit-cell dimensions of a = 47.7 Å, b = 182.0 Å and c = 175.8 Å. Assuming that the asymmetric unit contains one or two molecules (Mw 52 700), the Vm value is calculated as 3.6 or 1.8 Å 3/dalton, respectively. The crystals diffract X-rays to at least 3 Å resolution and are suitable for high resolution X-ray crystal structure determination.

  18. When, how, and where can oral cholera vaccines be used to interrupt cholera outbreaks?

    Science.gov (United States)

    Clemens, John; Holmgren, Jan

    2014-01-01

    Cholera continues to be a major global health problem, at times causing major and prolonged outbreaks in both endemic and nonendemic settings in developing countries. While improved water quality, sanitation, and hygiene (WASH) will provide the ultimate solution to prevention of this disease burden, this is a far-off goal for most developing countries. Oral cholera vaccines cholera vaccines (OCVs) have been demonstrated to be effective in the control of cholera outbreaks, and constitute useful tools to be used in conjunction with efforts to improve WASH. Two killed OCVs are prequalified by WHO for purchase by UN agencies for international use. Recently, WHO has launched a global stockpile stockpile of killed OCVs for use to control outbreaks. Rational deployment of OCV from this stockpile will require consideration of costs, feasibility, disease epidemiology epidemiology , and the protective characteristics of the vaccine deployed, as well as effective and rapid coordination of processes and logistics logistics used to make decisions on deployment and delivery of the vaccine to the population in need. Despite not having data on all the questions of relevance as to how to use OCVs to control cholera outbreaks in different settings, there is clearly more than enough evidence to initiate their use, as answers to remaining questions and refinement of policies will mainly come with experience.

  19. Transmission dynamics of cholera: Mathematical modeling and control strategies

    Science.gov (United States)

    Sun, Gui-Quan; Xie, Jun-Hui; Huang, Sheng-He; Jin, Zhen; Li, Ming-Tao; Liu, Liqun

    2017-04-01

    Cholera, as an endemic disease around the world, has generated great threat to human society and caused enormous morbidity and mortality with weak surveillance system. In this paper, we propose a mathematical model to describe the transmission of Cholera. Moreover, basic reproduction number and the global dynamics of the dynamical model are obtained. Then we apply our model to characterize the transmission process of Cholera in China. It was found that, in order to avoid its outbreak in China, it may be better to increase immunization coverage rate and make effort to improve environmental management especially for drinking water. Our results may provide some new insights for elimination of Cholera.

  20. Modern cholera in the Americas: an opportunistic societal infection.

    Science.gov (United States)

    Cerda, Rodrigo; Lee, Patrick T

    2013-11-01

    In the Americas, the only two cholera epidemics of the past century have occurred in the past 25 years. Lessons from the 1991 Peruvian cholera epidemic can help to focus and refine the response to the current Haitian epidemic. After three years of acute epidemic response, we have an opportunity to refocus on the chronic conditions that make societies vulnerable to cholera. More importantly, even as international attention wanes in the aftermath of the earthquake and acute epidemic, we are faced with a need for continued and coordinated investment in improving Haiti's structural defenses against cholera, in particular access to improved water and sanitation.

  1. Cholera in Portugal, 1974. II. Transmission by bottled mineral water.

    Science.gov (United States)

    Blake, P A; Rosenberg, M L; Florencia, J; Costa, J B; do Prado Quintino, L; Gangarosa, E J

    1977-04-01

    During a cholera epidemic, Vibrio cholerae was isolated from two springs which supplied mineral water to a spa and to a commercial water bottling plant. Epidemiologic investigation found that cholera attack rates were 10-fold greater among visitors to the spa than among non-visitors. A subsequent matched-pair case-control study which excluded persons who had visted the spa showed that a history of consumption of the bottled non-carbonated water was significantly more common among bacteriologically confirmed cholera cases than among paired controls.

  2. Impact of Air Temperature and SST Variability on Cholera Incidence in Southeastern Africa, 1971-2006

    Science.gov (United States)

    Paz, Shlomit

    2010-05-01

    Poisson regression model is suggested: log{E(CHOLt)} = b0+b1×Xt+b2×Xt-1 where: CHOLt = the number of new cases of cholera in year t Xt / Xt-1 = the climate covariate measured in year t/t-1. (b0,b1) = the coefficients. A first order autocorrelation, AR1 = cor(Yt, Yt-1) is taken into account in the estimation using Generalized Estimating Equations. b1 and b2 quantify the association of CHOL and X, i.e. if Xt or Xt-1 increase by one unit, the mean of Yt is expected to increase in exp{b1} or exp{b2} times, respectively (multiplicative model). The results showed a significant exponential increase of cholera rates in humans during the study period, with an estimate of exp(b1)=1.08 (p-value = 0.02). Associations have been found between the annual increase of the air temperature in southeastern Africa and the cholera incidence in the same area. Linkages were found also for a wider scale, with the air temperature anomaly of the Southern Hemisphere, with an estimate of exp(b1)=1.18 (p-value = 0.04) and exp(b1)=1.26 (p-value = 0.006) for the previous year. Significant linkages were detected between the annual cholera rate and the annual western Indian Ocean' SST , with exp(b1) = 1.31 (p-value = 0.01) for the current year and exp(b1) = 1.23 (p-value = 0.05) for the previous year. Linkages were found also for the hemispheric scale, with the SST anomaly. The increase of global temperature may influence the temporal fluctuations of cholera, as well as potentially increasing the frequency and duration of its outbreaks. Despite future uncertainty, the climate variability has to be considered in predicting further cholera outbreaks in Africa. This may help to promote better, more efficient preparedness. For more details: Paz, S. 2010. Impact of Temperature Variability on Cholera Incidence in Southeastern Africa, 1971-2006. EcoHealth, in press.

  3. Genomic and phenotypic characterization of Vibrio cholerae non-O1 isolates from a US Gulf Coast cholera outbreak.

    Directory of Open Access Journals (Sweden)

    Bradd J Haley

    Full Text Available Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

  4. Comparative microscopy study of Vibrio cholerae flagella

    Science.gov (United States)

    Konnov, Nikolai P.; Baiburin, Vil B.; Zadnova, Svetlana P.; Volkov, Uryi P.

    1999-06-01

    A fine structure of bacteria flagella is an important problem of molecular cell biology. Bacteria flagella are the self-assembled structures that allow to use the flagellum protein in a number of biotechnological applications. However, at present, there is a little information about high resolution scanning probe microscopy study of flagellum structure, in particular, about investigation of Vibrio cholerae flagella. In our lab have been carried out the high resolution comparative investigation of V. cholerae flagella by means of various microscopes: tunneling (STM), scanning force (SFM) and electron transmission. As a scanning probe microscope is used designed in our lab versatile SPM with replaceable measuring heads. Bacteria were grown, fixed and treated according to the conventional techniques. For STM investigations samples were covered with Pt/Ir thin films by rotated vacuum evaporation, in SFM investigations were used uncovered samples. Electron microscopy of the negatively stained bacteria was used as a test procedure.

  5. Catechol Siderophore Transport by Vibrio cholerae

    OpenAIRE

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

    2015-01-01

    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....

  6. Origins of the current seventh cholera pandemic.

    Science.gov (United States)

    Hu, Dalong; Liu, Bin; Feng, Lu; Ding, Peng; Guo, Xi; Wang, Min; Cao, Boyang; Reeves, Peter R; Wang, Lei

    2016-11-29

    Vibrio cholerae has caused seven cholera pandemics since 1817, imposing terror on much of the world, but bacterial strains are currently only available for the sixth and seventh pandemics. The El Tor biotype seventh pandemic began in 1961 in Indonesia, but did not originate directly from the classical biotype sixth-pandemic strain. Previous studies focused mainly on the spread of the seventh pandemic after 1970. Here, we analyze in unprecedented detail the origin, evolution, and transition to pandemicity of the seventh-pandemic strain. We used high-resolution comparative genomic analysis of strains collected from 1930 to 1964, covering the evolution from the first available El Tor biotype strain to the start of the seventh pandemic. We define six stages leading to the pandemic strain and reveal all key events. The seventh pandemic originated from a nonpathogenic strain in the Middle East, first observed in 1897. It subsequently underwent explosive diversification, including the spawning of the pandemic lineage. This rapid diversification suggests that, when first observed, the strain had only recently arrived in the Middle East, possibly from the Asian homeland of cholera. The lineage migrated to Makassar, Indonesia, where it gained the important virulence-associated elements Vibrio seventh pandemic island I (VSP-I), VSP-II, and El Tor type cholera toxin prophage by 1954, and it then became pandemic in 1961 after only 12 additional mutations. Our data indicate that specific niches in the Middle East and Makassar were important in generating the pandemic strain by providing gene sources and the driving forces for genetic events.

  7. CHOLERA EL-TOR EN IRAN

    Directory of Open Access Journals (Sweden)

    M. Ghodssi

    1969-01-01

    Full Text Available The bacteriological analysis shows that we have been confronted with the ELTor type, and only that type, until the end of the epidemic.The clinical study presents the symptoms of the real cholera with all its grievous consequences.The epidemiological supertnisicn stales that the El..Tor cholera is not agressiveat all in town areas whereas it presents its usual aspect in country areas, because of a lack of hygiene. there.That disease can be completely cured if the balance between the electrolytesis quickly restored.The disease was all the more dreadful since it came as a surprise and spread from one province to the other.L'examen bacteriologique montrc qu'il s'agit du type EI_ Tor et uniquement du meme type jusqu'a la fin de l'epldemie.La surveillance epidemiologique constate que Ie cholera EI_Tor n'cst nullement agressif dans Ie milieu urbain; mais qu'H revet l'aspect classique dans les milieuxruraux, depourvus d'hyglene.La maludic est totalement guerissablc a condition que l'equilibre des electrolytes so it rapidement retabli. L'evenement a tHe maladie se repandit d'une12

  8. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

    Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

    2013-12-01

    Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

  9. 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

  10. Synthetic multivalent ligands for cholera & cholera-like toxins: Protected cyclic neoglycopeptides.

    Science.gov (United States)

    Kumar, Vajinder; Yadav, Narender; Kartha, K P Ravindranathan

    2016-08-05

    Synthesis of a set of novel glycopeptide analogues as potential cholera/cholera-like toxin inhibitors in their protected form is described. They include di-, tri-, tetra- and pentavalent scaffolds. The synthetic steps were achieved using a combination of solvent-free mechanochemical as well as the conventional solution-phase reactions. During the conventional DIC-HOBt-mediated peptide coupling followed for the preparation of certain glycopeptide analogues an interesting in situ Fmoc deprotection was observed which has been demonstrated to hold potential for synthesiszing glycopeptides/neoglycopeptides with extended polyamide chains.

  11. A large cholera outbreak due to a new cholera toxin variant of the Vibrio cholerae O1 El Tor biotype in Orissa, Eastern India.

    Science.gov (United States)

    Kumar, P; Jain, M; Goel, A K; Bhadauria, S; Sharma, S K; Kamboj, D V; Singh, L; Ramamurthy, T; Nair, G B

    2009-02-01

    A total of 32 Vibrio cholerae isolates were collected during a recent large cholera outbreak in Eastern India. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. Two multiplex PCR assays confirmed the presence of various toxigenic and pathogenic genes - ace, ctxAB, hlyA, ompU, ompW, rfbO1, rtx, tcp, toxR and zot - in all of the isolates. Sequencing of the ctxB gene from the isolates revealed a novel mutation in the gene. Sequencing also confirmed the presence of altered cholera toxin B of the classical biotype in all of the El Tor isolates, suggesting infection of isolates by classical CTXPhi. The molecular diversity of V. cholerae isolates studied by enterobacterial repetitive intergenic consensus sequence PCR, BOX-PCR and randomly amplified polymorphic DNA analysis uniformly showed the clonal relationship among the outbreak V. cholerae O1 isolates. The results of this study suggest that cholera-causing V. cholerae strains are constantly evolving in epidemic areas, highlighting the potential of the emergence of more virulent strains.

  12. Dimethyl sulphoxide and Ca2+ stimulate assembly of Vibrio cholerae FtsZ.

    Science.gov (United States)

    Chatterjee, Abhisek; Chakrabarti, Gopal

    2014-10-01

    We cloned, overexpressed and purified Vibrio cholerae FtsZ protein for the first time. We used several complementary techniques to probe and compare the comparative assembly properties of recombinant Vibrio cholerae FtsZ (VcFtsZ) and Escherichia coli FtsZ (EcFtsZ). We observed that VcFtsZ polymerized at a slower rate than EcFtsZ and interestingly its polymerization was highly dependent on the presence of Ca(2+) ion. Furthermore, DMSO specifically modulated the polymerization of VcFtsZ, promoted polymer bundling and increased the stability of the VcFtsZ protofilaments. Whereas DMSO showed no significant stimulatory effect on the assembly and bundling of EcFtsZ. Transmission electron microscopy experiments demonstrated that in presence of 8% DMSO the average thickness of the VcFtsZ polymers were increased significantly. DMSO specifically stabilized the VcFtsZ polymers against dilution induced disassembly and it reduced the GTPase activity of VcFtsZ. These results collectively suggested that despite lot of sequence homology, the assembly of VcFtsZ and EcFtsZ are differently regulated processes. We expect to use this knowledge of assembly properties of VcFtsZ for screening of small molecules against VcFtsZ for development of anti-cholera agent.

  13. Update on Comprehensive Management of Cholera. Recommendations of the Expert Workshop. Cienfuegos 2014

    Directory of Open Access Journals (Sweden)

    María Lina Valdés Gómez

    2014-10-01

    Full Text Available Cholera is a reemerging disease that was reintroduced into Cuba in late 2012. A provincial workshop attended by 83 professionals from the health institutions in the territory was developed on August 27, 2014 in order to analyse the technical elements for prevention and management of cholera outbreaks and to improve the provincial prevention and control plan for this disease. Group techniques including brainstorming and focus group were applied. Finally, the groups met to present their recommendations and approve the document. Main areas for improvement are related to: keeping an intensive training program, particularly for new professionals and technicians; having safe means for disinfecting and washing contaminated clothes; developing a health promotion and prevention strategy related to “clean hands” and “safe drinking water”; improving the information flow and intra- and inter-sectoral collaboration. It is concluded that the cholera prevention and control plan comprises the technical elements for an appropriate response; however, it can be improved by means of new training and control actions, increased risk perception among health professionals and in the communities, effective control of events and improved networking and inter-sectoral work.

  14. Phenotypic and Genetic Heterogeneity in Vibrio cholerae O139 Isolated from Cholera Cases in Delhi, India during 2001-2006.

    Science.gov (United States)

    Ghosh, Raikamal; Sharma, Naresh C; Halder, Kalpataru; Bhadra, Rupak K; Chowdhury, Goutam; Pazhani, Gururaja P; Shinoda, Sumio; Mukhopadhyay, Asish K; Nair, G Balakrish; Ramamurthy, Thadavarayan

    2016-01-01

    Incidence of epidemic Vibrio cholerae serogroup O139 has declined in cholera endemic countries. However, sporadic cholera caused by V. cholerae O139 with notable genetic changes is still reported from many regions. In the present study, 42 V. cholerae O139 strains isolated from 2001 to 2006 in Delhi, India, were retrospectively analyzed to understand their phenotype and molecular characteristics. The majority of isolates were resistant to ampicillin, furazolidone and nalidixic acid. Though the integrative conjugative element was detected in all the O139 isolates, the 2004-2006 isolates remained susceptible to co-trimoxazole, chloramphenicol, and streptomycin. Cholera toxin genotype 1 was present in the majority of the O139 isolates while few had type 3 or a novel type 4. In the cholera toxin encoding gene (ctx) restriction fragment length polymorphism, the majority of the isolates harbored three copies of CTX element, of which one was truncated. In this study, the ctx was detected for the first time in the small chromosome of V. cholerae O139 and one isolate harbored 5 copies of CTX element, of which 3 were truncated. The ribotype BII pattern was found in most of the O139 isolates. Three V. cholerae O139 isolated in 2001 had a new ribotype BVIII. Pulsed-field gel electrophoresis analysis revealed clonal variation in 2001 isolates compared to the 2004-2006 isolates. Molecular changes in V. cholerae O139 have to be closely monitored as this information may help in understanding the changing genetic features of this pathogen in relation to the epidemiology of cholera.

  15. Phenotypic and Genetic Heterogeneity in Vibrio cholerae O139 Isolated from Cholera Cases in Delhi, India during 2001-2006

    Directory of Open Access Journals (Sweden)

    Raikamal Ghosh

    2016-08-01

    Full Text Available Incidence of epidemic Vibrio cholerae serogroup O139 has declined in cholera endemic countries. However, sporadic cholera caused by V. cholerae O139 with notable genetic changes is still reported from many regions. In the present study, 42 V. cholerae O139 strains isolated from 2001 to 2006 in Delhi, India, were retrospectively analyzed to understand their phenotype and molecular characteristics. The majority of isolates were resistant to ampicillin, furazolidone and nalidixic acid. Though the integrative conjugative element was detected in all the O139 isolates, the 2004-2006 isolates remained susceptible to co-trimoxazole, chloramphenicol, and streptomycin. Cholera toxin genotype 1 was present in the majority of the O139 isolates while few had type 3 or a novel type 4. In the cholera toxin encoding gene (ctx restriction fragment length polymorphism, the majority of the isolates harbored three copies of CTX element, of which one was truncated. In this study, the ctx was detected for the first time in the small chromosome of V. cholerae O139 and one isolate harbored 5 copies of CTX element, of which 3 were truncated. The ribotype BII pattern was found in most of the O139 isolates. Three V. cholerae O139 isolated in 2001 had a new ribotype BVIII. Pulsed-field gel electrophoresis analysis revealed clonal variation in 2001 isolates compared to the 2004-2006 isolates. Molecular changes in V. cholerae O139 have to be closely monitored as this information may help in understanding the changing genetic features of this pathogen in relation to the epidemiology of cholera.

  16. 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.

  17. Cholera with severe renal failure in an Italian tourist returning from Cuba, July 2013.

    Science.gov (United States)

    Mascarello, M; Deiana, M L; Maurel, C; Lucarelli, C; Luzzi, I; Luzzati, R

    2013-08-29

    In July 2013, an Italian tourist returning from Cuba was hospitalised in Trieste, Italy, for cholera caused by Vibrio cholerae O1 serotype Ogawa with severe renal failure. An outbreak of cholera was reported in Cuba in January 2013. Physicians should consider the diagnosis of cholera in travellers returning from Cuba presenting with acute watery diarrhoea.

  18. Characterisation of cholera toxin by liquid chromatography - Electrospray mass spectrometry

    NARCIS (Netherlands)

    Baar, B.L.M. van; Hulst, A.G.; Wils, E.R.J.

    1999-01-01

    Cholera toxin, one of the toxins that may be generated by various strains of the bacterium Vibrio cholerae, can be considered as a substance possibly used in biological warfare. The possibilities of characterising the toxin by liquid chromatography electrospray mass spectrometry (LC-ES-MS) were inve

  19. 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 rev

  20. Malonate inhibits virulence gene expression in Vibrio cholerae.

    Science.gov (United States)

    Minato, Yusuke; Fassio, Sara R; Häse, Claudia C

    2013-01-01

    We previously found that inhibition of the TCA cycle, either through mutations or chemical inhibition, increased toxT transcription in Vibrio cholerae. In this study, we found that the addition of malonate, an inhibitor of succinate dehydrogenase (SDH), decreased toxT transcription in V. cholerae, an observation inconsistent with the previous pattern observed. Unlike another SDH inhibitor, 2-thenoyltrifluoroacetone (TTFA), which increased toxT transcription and slightly inhibited V. cholerae growth, malonate inhibited toxT transcription in both the wild-type strain and TCA cycle mutants, suggesting malonate-mediated inhibition of virulence gene expression is independent to TCA cycle activity. Addition of malonate also inhibited ctxB and tcpA expressions but did not affect aphA, aphB, tcpP and toxR expressions. Malonate inhibited cholera toxin (CT) production in both V. cholerae classical biotype strains O395N1 and CA401, and El Tor biotype strain, N16961. Consistent with previous reports, we confirmed that these strains of V. cholerae did not utilize malonate as a primary carbon source. However, we found that the addition of malonate to the growth medium stimulated V. cholerae growth. All together, these results suggest that metabolizing malonate as a nutrient source negatively affects virulence gene expression in V. cholerae.

  1. Understanding the Hydrology of Cholera in South Asia

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Islam, S.

    2007-12-01

    Cholera is an acute waterborne illness caused by the bacterium Vibrio cholerae. The disease remains a major public health issue in several regions of the developing world, mainly in coastal areas around the tropics. Cholera incidences have been historically linked to climate variables and more recently with El Nino-Southern Oscillation. The occurrence of cholera shows bi-annual seasonal peaks and strong inter-annual variability in the Ganges basin region of South Asia. However, the role of hydrologic variables in the seasonal patterns of cholera epidemics is less understood. Preliminary results suggest that a unique combination of increasing water temperature and higher salinity in the coastal zone during the low flow season provide the situation amenable to the first outbreak of cholera in the spring season. Other major factors contributing to the subsequent spread of the disease are sea surface height, monsoon precipitation, and coastal phytoplankton concentration. We will further examine the lag periods between the dominant environmental variables and cholera incidences to understand the seasonal dynamics of cholera in South Asia.

  2. Satellite Water Impurity Marker (SWIM) for predicting seasonal cholera outbreaks

    Science.gov (United States)

    Jutla, A. S.; Akanda, A. S.; Islam, S.

    2011-12-01

    Prediction of outbreaks of cholera, a deadly water related disease, remains elusive. Since coastal brackish water provides a natural ecological niche for cholera bacteria and because a powerful evidence of new biotypes is emerging, it is highly unlikely that cholera will be fully eradicated. Therefore, it is necessary to develop cholera prediction model with several months' of lead time. Satellite based estimates of chlorophyll, a surrogate for phytoplankton abundance, has been associated with proliferation of cholera bacteria. However, survival of cholera bacteria in a variety of coastal ecological environment put constraints on predictive abilities of chlorophyll algorithm since it only measures greenness in coastal waters. Here, we propose a new remote sensing reflectance based statistical index: Satellite Water Impurity Marker, or SWIM. This statistical index estimates impurity levels in the coastal waters and is based on the variability observed in the difference between the blue (412nm) and green (555nm) wavelengths in coastal waters. The developed index is bounded between clear and impure water and shows the ability to predict cholera outbreaks in the Bengal Delta with a predicted r2 of 78% with two months lead time. We anticipate that a predictive system based on SWIM will provide essential lead time allowing effective intervention and mitigation strategies to be developed for other cholera endemic regions of the world.

  3. USE OF MODIFIED CAMP TEST FOR PRELIMINARY NONSEROLOGIC IDENTIFICATION OF VIBRIO CHOLERAE IN STOOL SPECIMENS

    Directory of Open Access Journals (Sweden)

    Murad Lesmana

    2012-09-01

    Full Text Available Suatu modifikasi uji CAMP digunakan bersama dengan reaksi biokimiawi untuk identifikasi Vibrio cholerae pada sampel klinis. Dari 579 usap dubur penderita diare, 92 (16% memberikan hasil isolasi V. cholerae 01 biotipe El Tor dan 34 (6% V. cholerae non-01. Semua isolat V. cholerae 01 El Tor menunjukkan reaksi CAMP positif kuat dengan gambaran hemolisis sinergistik lengkap berbentuk sosis; sedangkan V. cholerae non-01 memberikan reaksi CAMP yang sempit dengan pola hemolisis menyerupai bulan sabit. Hasil uji CAMP yang dilakukan bersama dengan reaksi biokimiawi sesuai dengan metode biakan konvensional yang menyertakan tes aglutinasi dengan antiserum V. cholerae 01 untuk mengidentifikasi V. cholerae.

  4. Intestinal GPS: bile and bicarbonate control cyclic di-GMP to provide Vibrio cholerae spatial cues within the small intestine.

    Science.gov (United States)

    Koestler, Benjamin J; Waters, Christopher M

    2014-01-01

    The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase of intracellular c-di-GMP is negated by bicarbonate, and that this interaction is dependent on pH, suggesting that V. cholerae uses these 2 environmental cues to sense and adapt to its relative location in the small intestine. Increased intracellular c-di-GMP by bile is attributed to increased c-di-GMP synthesis by 3 diguanylate cyclases (DGCs) and decreased expression of one phosphodiesterase (PDE) in the presence of bile. The molecular mechanisms by which bile controls the activity of the 3 DGCs and the regulators of bile-mediated transcriptional repression of the PDE are not yet known. Moreover, the impact of varying concentrations of bile and bicarbonate at different locations within the small intestine and the response of V. cholerae to these cues remains unclear. The native microbiome and pharmaceuticals, such as omeprazole, can impact bile and pH within the small intestine, suggesting these are potential unappreciated factors that may alter V. cholerae pathogenesis.

  5. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

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

    The role of in-house transmission on the incidence of Vibrio cholerae, the deadly waterborne pathogen, is still not developed. The aim of the current study was to investigate possible contamination routes in household domain for effective cholera control in Bangladesh. To examine the prevalence...... and water supply may be the reason behind this relatively high presence of virulence factors in food plates and water pots. Direct exposure routes of disease transmission should be a major consideration in cholera prevention policies. Investigation of household contamination of Vibrio cholerae in Bangladesh........ Available from: https://www.researchgate.net/publication/305215719_Investigation_of_household_contamination_of_Vibrio_cholerae_in_Bangladesh [accessed Oct 14, 2016]....

  6. epidemiological and Clinical Characteristics of 28 cases of Cholera

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    The data of 35 246 patients with intestinal diseases were retrospectively analyzed, 28 cases of cholera patients were screened in 17 years, of which 23 cases had suspicious unclean food history, 10 cases were migrant workers, 8 cases had history of coastal city tour in one week. All of the 28 patients were positive for Vibrio cholerae culture, 19 cases were identiifed as O1 serotype Ogawa and 6 were identiifed as O1 serotype Inaba, 3 were identified as O139. Twenty-three patients were mild, five cases were moderate, patients with severe diseases were not found. It was found in this study that O1 serotype Vibrio cholerae was still dominant, 82%of cholera patients were mild cases. Tourists who had a incompletely heated seafood intake history and migrant people are susceptible to cholera.

  7. Zebrafish as a natural host model for Vibrio cholerae colonization and transmission.

    Science.gov (United States)

    Runft, Donna L; Mitchell, Kristie C; Abuaita, Basel H; Allen, Jonathan P; Bajer, Sarah; Ginsburg, Kevin; Neely, Melody N; Withey, Jeffrey H

    2014-03-01

    The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival.

  8. Multi-locus variable number tandem repeat analysis of Vibrio cholerae isolates from 2012 to 2013 cholera outbreaks in Iran.

    Science.gov (United States)

    Ranjbar, R; Sadeghy, J; Shokri Moghadam, M; Bakhshi, B

    2016-08-01

    Cholera remains to be an international threat, with high rates of illness and death. In 2012 and 2013, two cholera outbreak happened in Iran, affecting lots of people. Vibrio cholerae O1 was confirmed as the etiological agent. Source identification and controlling the spread of the cholera disease are two critical approaches in cholera outbreaks. In this study, thirty V. cholerae O1 isolates were selected and has been evaluated for antimicrobial resistant as well as molecular typing by multilocus variable-number tandem-repeat analysis (MLVA) method. Twenty-nine (97%) isolates were sero-grouped as El Tor (one isolate was classical) and 100% were related to Inaba serotype. All of the isolates were susceptible to ciprofloxacin, chloramphenicol, ampicillin and gentamicin. On the other hand, 60% of the isolates were MDR (resistant to 3 or more classes). There were three resistance patterns. The most prevalent pattern was resistance to streptomycin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline (ST-SXT-E-T) which was seen in 50% of isolates. Using MLVA method 14 MLVA types were identified. MLVA type 2 (5-7-7-16-15) accounted for 43% of isolates. Isolates with the same genotype often did not have the same antibiogram. Overall, the data indicate that the Iranian V. cholerae were MDR and clonaly related. Furthermore, the results of this study shows that MLVA can be used as useful method for V. cholerae genotyping in epidemiological investigations.

  9. Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

    NARCIS (Netherlands)

    Garza, D.R.; Thompson, C.C.; Loureiro, E.C.; Dutilh, B.E.; Inada, D.T.; Junior, E.C.; Cardoso, J.F.; Nunes, M.R.; Lima, C.P. de; Silvestre, R.V.; Nunes, K.N.; Santos, E.C.; Edwards, R.A.; Vicente, A.C.; Sá Morais, L.L. de

    2012-01-01

    The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic char

  10. YgbQ, a cell division protein in Escherichia coli and Vibrio cholerae, localizes in codependent fashion with FtsL to the division site

    OpenAIRE

    Buddelmeijer, Nienke; Judson, Nicholas; Boyd, Dana; Mekalanos, John J.; Beckwith, Jonathan

    2002-01-01

    YgbQ is a cell division protein in Escherichia coli and Vibrio cholerae. In E. coli the ygbQ gene was discovered as a result of a computer search of the E. coli genome designed to find potential interacting partners for cell division protein FtsL. In V. cholerae, ygbQ was identified as an essential gene by using a transposon that fuses genes to an arabinose promoter. The role of YgbQ in cell division is supported by the following. Cells depleted of YgbQ in both organisms form long filaments, ...

  11. Intestinal GPS: bile and bicarbonate control cyclic di-GMP to provide Vibrio cholerae spatial cues within the small intestine

    OpenAIRE

    Koestler, Benjamin J.; Waters, Christopher M.

    2015-01-01

    The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase ...

  12. Immunization with cholera toxin B subunit induces high-level protection in the suckling mouse model of cholera.

    Directory of Open Access Journals (Sweden)

    Gregory A Price

    Full Text Available Cholera toxin (CT is the primary virulence factor responsible for severe cholera. Vibrio cholerae strains unable to produce CT show severe attenuation of virulence in animals and humans. The pentameric B subunit of CT (CTB contains the immunodominant epitopes recognized by antibodies that neutralize CT. Although CTB is a potent immunogen and a promising protective vaccine antigen in animal models, immunization of humans with detoxified CT failed to protect against cholera. We recently demonstrated however that pups reared from mice immunized intraperitoneally (IP with 3 doses of recombinant CTB were well protected against a highly lethal challenge dose of V. cholerae N16961. The present study investigated how the route and number of immunizations with CTB could influence protective efficacy in the suckling mouse model of cholera. To this end female mice were immunized with CTB intranasally (IN, IP, and subcutaneously (SC. Serum and fecal extracts were analyzed for anti-CTB antibodies by quantitative ELISA, and pups born to immunized mothers were challenged orogastrically with a lethal dose of V. cholerae. Pups from all immunized groups were highly protected from death by 48 hours (64-100% survival. Cox regression showed that percent body weight loss at 24 hours predicted death by 48 hours, but we were unable to validate a specific amount of weight loss as a surrogate marker for protection. Although CTB was highly protective in all regimens, three parenteral immunizations showed trends toward higher survival and less weight loss at 24 hours post infection. These results demonstrate that immunization with CTB by any of several routes and dosing regimens can provide protection against live V. cholerae challenge in the suckling mouse model of cholera. Our data extend the results of previous studies and provide additional support for the inclusion of CTB in the development of a subunit vaccine against V. cholerae.

  13. Immunization with cholera toxin B subunit induces high-level protection in the suckling mouse model of cholera.

    Science.gov (United States)

    Price, Gregory A; McFann, Kim; Holmes, Randall K

    2013-01-01

    Cholera toxin (CT) is the primary virulence factor responsible for severe cholera. Vibrio cholerae strains unable to produce CT show severe attenuation of virulence in animals and humans. The pentameric B subunit of CT (CTB) contains the immunodominant epitopes recognized by antibodies that neutralize CT. Although CTB is a potent immunogen and a promising protective vaccine antigen in animal models, immunization of humans with detoxified CT failed to protect against cholera. We recently demonstrated however that pups reared from mice immunized intraperitoneally (IP) with 3 doses of recombinant CTB were well protected against a highly lethal challenge dose of V. cholerae N16961. The present study investigated how the route and number of immunizations with CTB could influence protective efficacy in the suckling mouse model of cholera. To this end female mice were immunized with CTB intranasally (IN), IP, and subcutaneously (SC). Serum and fecal extracts were analyzed for anti-CTB antibodies by quantitative ELISA, and pups born to immunized mothers were challenged orogastrically with a lethal dose of V. cholerae. Pups from all immunized groups were highly protected from death by 48 hours (64-100% survival). Cox regression showed that percent body weight loss at 24 hours predicted death by 48 hours, but we were unable to validate a specific amount of weight loss as a surrogate marker for protection. Although CTB was highly protective in all regimens, three parenteral immunizations showed trends toward higher survival and less weight loss at 24 hours post infection. These results demonstrate that immunization with CTB by any of several routes and dosing regimens can provide protection against live V. cholerae challenge in the suckling mouse model of cholera. Our data extend the results of previous studies and provide additional support for the inclusion of CTB in the development of a subunit vaccine against V. cholerae.

  14. Tagging a Vibrio cholerae El Tor candidate vaccine strain by disruption of its hemagglutinin/protease gene using a novel reporter enzyme: Clostridium thermocellum endoglucanase A.

    Science.gov (United States)

    Robert, A; Silva, A; Benitez, J A; Rodriguez, B L; Fando, R; Campos, J; Sengupta, D K; Boesman-Finkelstein, M; Finkelstein, R A

    1996-11-01

    The celA gene encoding Clostridium thermocellum endoglucanase A was expressed in Vibrio cholerae on its own promoter and used to tag a candidate El Tor biotype cholera vaccine strain. Colonies of the tagged strain could be unequivocally distinguished by overlaying them with CM-cellulose indicator agar and Congo Red staining. Expression of celA did not affect growth of V. cholerae in vitro and in vivo. The celA gene was inserted in the chromosomal hap locus encoding V. cholerae hemagglutinin/protease, a putative "detachase", to create a hap- mutant that could be identified and scored by its halo of cellulolytic activity. The inactivation of hap had a positive effect on colonization in the infant mice model. The above results indicate that celA is a suitable marker gene for V. cholerae and hap is an appropriate locus for insertion of foreign DNA in vaccine development. Inactivation of hap, by increasing the duration of adherence, might decrease excretion of the resulting vaccine vector strain and thus increase its immunogenicity.

  15. 1.65 Å resolution structure of the AraC-family transcriptional activator ToxT from Vibrio cholerae.

    Science.gov (United States)

    Li, Jiaqin; Wehmeyer, Graham; Lovell, Scott; Battaile, Kevin P; Egan, Susan M

    2016-09-01

    ToxT is an AraC-family transcriptional activator protein that controls the expression of key virulence factors in Vibrio cholerae, the causative agent of cholera. ToxT directly activates the expression of the genes that encode the toxin-coregulated pilus and cholera toxin, and also positively auto-regulates its own expression from the tcp promoter. The crystal structure of ToxT has previously been solved at 1.9 Å resolution (PDB entry 3gbg). In this study, a crystal structure of ToxT at 1.65 Å resolution with a similar overall structure to the previously determined structure is reported. However, there are distinct differences between the two structures, particularly in the region that extends from Asp101 to Glu110. This region, which can influence ToxT activity but was disordered in the previous structure, can be traced entirely in the current structure.

  16. Removal of Cholera Toxin from Aqueous Solution by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Jussi A. O. Meriluoto

    2012-06-01

    Full Text Available Cholera remains a serious health problem, especially in developing countries where basic hygiene standards are not met. The symptoms of cholera are caused by cholera toxin, an enterotoxin, which is produced by the bacterium Vibrio cholerae. We have recently shown that human probiotic bacteria are capable of removing cyanobacterial toxins from aqueous solutions. In the present study we investigate the ability of the human probiotic bacteria, Lactobacillus rhamnosus strain GG (ATCC 53103 and Bifidobacterium longum 46 (DSM 14583, to remove cholera toxin from solution in vitro. Lactobacillus rhamnosus strain GG and Bifidobacterium longum 46 were able to remove 68% and 59% of cholera toxin from aqueous solutions during 18 h of incubation at 37 °C, respectively. The effect was dependent on bacterial concentration and L. rhamnosus GG was more effective at lower bacterial concentrations. No significant effect on cholera toxin concentration was observed when nonviable bacteria or bacterial supernatant was used.

  17. Molecular tools in understanding the evolution of Vibrio cholerae.

    Science.gov (United States)

    Rahaman, Md Habibur; Islam, Tarequl; Colwell, Rita R; Alam, Munirul

    2015-01-01

    Vibrio cholerae, the etiological agent of cholera, has been a scourge for centuries. Cholera remains a serious health threat for developing countries and has been responsible for millions of deaths globally over the past 200 years. Identification of V. cholerae has been accomplished using a variety of methods, ranging from phenotypic strategies to DNA based molecular typing and currently whole genomic approaches. This array of methods has been adopted in epidemiological investigations, either singly or in the aggregate, and more recently for evolutionary analyses of V. cholerae. Because the new technologies have been developed at an ever increasing pace, this review of the range of fingerprinting strategies, their relative advantages and limitations, and cholera case studies was undertaken. The task was challenging, considering the vast amount of the information available. To assist the study, key references representative of several areas of research are provided with the intent to provide readers with a comprehensive view of recent advances in the molecular epidemiology of V. cholerae. Suggestions for ways to obviate many of the current limitations of typing techniques are also provided. In summary, a comparative report has been prepared that includes the range from traditional typing to whole genomic strategies.

  18. Cholera in Indonesia: epidemiologic studies of transmission in Aceh Province.

    Science.gov (United States)

    Glass, R I; Alim, A R; Eusof, A; Snyder, J D; Jusuf, B; Anwar, S; Bakri, Z; Helmi, C; Winardi, B

    1984-09-01

    To determine the modes of transmission of cholera in the regency of Pidie, Indonesia, and to consider strategies for its control, we set up a laboratory to identify Vibrio cholerae 01 from patients with severe diarrhea in all government clinics in the regency and questioned culture-positive cases and neighborhood controls about possible exposures to V. cholerae 01. Between 12 July and 15 August 1982, 63 of 138 suspected cholera cases were confirmed by the laboratory; 53 of these patients were seen and followed up. We were unable to identify a single, indisputable mode of transmission for cholera which was amenable to immediate control. Nonetheless, a number of factors, including exposure to water from the Tiro-Sigli River and consumption of ice, were associated with disease. Other findings bring into question the value of current practices of chlorinating dugwells and disinfecting homes with Lysol during a cholera outbreak. The case-control approach to investigating the mode of transmission of cholera has distinct limitations when applied in endemic setting where there may not be a single predominant vehicle of transmission, or where the vehicle such as river water is used by all and is only periodically contaminated.

  19. The VrrA sRNA controls a stationary phase survival factor Vrp of Vibrio cholerae.

    Science.gov (United States)

    Sabharwal, Dharmesh; Song, Tianyan; Papenfort, Kai; Wai, Sun Nyunt

    2015-01-01

    Small non-coding RNAs (sRNAs) are emerging regulatory elements in bacteria. The Vibrio cholerae sRNA VrrA has previously been shown to down-regulate outer membrane proteins (OmpA and OmpT) and biofilm matrix protein (RbmC) by base-pairing with the 5' region of the corresponding mRNAs. In this study, we present an additional target of VrrA in V. cholerae, the mRNA coding for the ribosome binding protein Vrp. Vrp is homologous to ribosome-associated inhibitor A (RaiA) of Escherichia coli which facilitates stationary phase survival through ribosome hibernation. We show that VrrA down-regulates Vrp protein synthesis by base-pairing to the 5' region of vrp mRNA and that the regulation requires the RNA chaperone protein, Hfq. We further demonstrate that Vrp is highly expressed during stationary phase growth and associates with the ribosome of V. cholerae. The effect of the Vrp protein in starvation survival is synergistic with that of the VC2530 protein, a homolog of the E. coli hibernation promoting factor HPF, suggesting a combined role for these proteins in ribosome hibernation in V. cholerae. Vrp and VC2530 are important for V. cholerae starvation survival under nutrient deficient conditions. While VC2530 is down-regulated in cells lacking vrrA, mutation of vrp results in VC2530 activation. This is the first report indicating a regulatory role for an sRNA, modulating stationary factors involved in bacterial ribosome hibernation.

  20. Expression of the cholera toxin B subunit (CT-B) in maize seeds and a combined mucosal treatment against cholera and traveler's diarrhea.

    Science.gov (United States)

    Karaman, S; Cunnick, J; Wang, K

    2012-03-01

    The non-toxic B subunit (CT-B) of cholera toxin from Vibrio cholerae is a strong immunogen and amplifies the immune reaction to conjugated antigens. In this work, a synthetic gene encoding for CT-B was expressed under control of a γ-zein promoter in maize seeds. Levels of CT-B in maize plants were determined via ganglioside dependent ELISA. The highest expression level recorded in T(1) generation seeds was 0.0014% of total aqueous soluble protein (TASP). Expression level of the same event in the T(2) generation was significantly increased to 0.0197% of TASP. Immunogenicity of maize derived CT-B was evaluated in mice with an oral immunization trial. Anti-CTB IgG and anti-CTB IgA were detected in the sera and fecal samples of the orally immunized mice, respectively. The mice were protected against holotoxin challenge with CT. An additional group of mice was administrated with an equal amount (5 μg per dose each) of mixed maize-derived CT-B and LT-B (B subunit of E. coli heat labile toxin). In the sera and fecal samples obtained from this group, the specific antibody levels were enhanced compared to either the same or a higher amount of CT-B alone. These results suggest that a synergistic action may be achieved using a CT-B and LT-B mixture that can lead to a more efficacious combined vaccine to target diarrhea induced by both cholera and enterotoxigenic strains of Escherichia coli.

  1. Survival of Vibrio cholerae O1 on fomites.

    Science.gov (United States)

    Farhana, Israt; Hossain, Zenat Zebin; Tulsiani, Suhella Mohan; Jensen, Peter Kjær Mackie; Begum, Anowara

    2016-09-01

    It is well established that the contamination sources of cholera causing bacteria, Vibrio cholerae, are water and food, but little is known about the transmission role of the fomites (surfaces that can carry pathogens) commonly used in households. In the absence of appropriate nutrients or growth conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass, plastic, cloth and several types of metals under laboratory conditions. The fomites were inoculated with an outbreak strain of V. cholerae and its culturability was examined by drop plate count method at 30 min intervals for up to 6 h. For molecular detection, the viable/dead stain ethidium monoazide (EMA) which inhibits amplification of DNA from dead cells was used in combination with real-time polymerase chain reaction (EMA-qPCR) for direct quantitative analyses of viable V. cholerae at 2, 4, 6, 24 h and 7 day time intervals. Results showed that V. cholerae on glass and aluminum surfaces lost culturability within one hour after inoculation but remained culturable on cloth and wood for up to four hours. VBNC V. cholerae on dry fomite surfaces was detected and quantified by EMA-qPCR even 7 days after inoculation. In conclusion, the prolonged survival of V. cholerae on various household fomites may play vital role in cholera transmission and needs to be further investigated.

  2. Dual expression profile of type VI secretion system immunity genes protects pandemic Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Sarah T Miyata

    Full Text Available The Vibrio cholerae type VI secretion system (T6SS assembles as a molecular syringe that injects toxic protein effectors into both eukaryotic and prokaryotic cells. We previously reported that the V. cholerae O37 serogroup strain V52 maintains a constitutively active T6SS to kill other Gram-negative bacteria while being immune to attack by kin bacteria. The pandemic O1 El Tor V. cholerae strain C6706 is T6SS-silent under laboratory conditions as it does not produce T6SS structural components and effectors, and fails to kill Escherichia coli prey. Yet, C6706 exhibits full resistance when approached by T6SS-active V52. These findings suggested that an active T6SS is not required for immunity against T6SS-mediated virulence. Here, we describe a dual expression profile of the T6SS immunity protein-encoding genes tsiV1, tsiV2, and tsiV3 that provides pandemic V. cholerae strains with T6SS immunity and allows T6SS-silent strains to maintain immunity against attacks by T6SS-active bacterial neighbors. The dual expression profile allows transcription of the three genes encoding immunity proteins independently of other T6SS proteins encoded within the same operon. One of these immunity proteins, TsiV2, protects against the T6SS effector VasX which is encoded immediately upstream of tsiV2. VasX is a secreted, lipid-binding protein that we previously characterized with respect to T6SS-mediated virulence towards the social amoeba Dictyostelium discoideum. Our data suggest the presence of an internal promoter in the open reading frame of vasX that drives expression of the downstream gene tsiV2. Furthermore, VasX is shown to act in conjunction with VasW, an accessory protein to VasX, to compromise the inner membrane of prokaryotic target cells. The dual regulatory profile of the T6SS immunity protein-encoding genes tsiV1, tsiV2, and tsiV3 permits V. cholerae to tightly control T6SS gene expression while maintaining immunity to T6SS activity.

  3. John Snow and cholera--the bicentenary of birth.

    Science.gov (United States)

    Gańczak, Maria

    2014-01-01

    The bicentenary of John Snow's birth, a legend in his field, for his research on epidemiology and the prevention ofcholera, constitutes a unique opportunity to commemorate this iconic figure. In the article, his spectacular achievements in this discipline are presented, including his epidemiological investigation during cholera epidemic and the well-known Broad Street intervention in Soho, in 1854, as well as his methodologically elegant experiment "on the grandest scale" in which he compared the cholera fatality rates in households served by two different water supply companies. Having referred to Snow's research, the cholera outbreak in Haiti in 2010 is also discussed.

  4. [Isolation of the R'his plasmids of Vibrio cholerae].

    Science.gov (United States)

    Rusina, O Iu; Tiganova, I G; Aleshkin, G I; Andreeva, I V; Skavronskaia, A G

    1987-06-01

    V. cholerae strain VT5104 capable of donor activity in conjugation has been constructed by the genetic technique based on plasmid RP4::Mucts62 integration into V. cholerae chromosome due to plasmid homology with Mucts62 inserted into the chromosome. The gene for histidine synthesis has been mobilized and transferred into the recipient cells from VT5104 donor. The conjugants obtained are able to efficiently transfer his+ gene included into the plasmid structure in conjugation with eltor recipient. Thus, the constructed strain VT5104 generates R' plasmids carrying V. cholerae chromosomal genes.

  5. 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.

  6. [The knowledge of the population about cholera].

    Science.gov (United States)

    de la Cruz, A M; de Rojas, V; Delgado, J; Alonso, A; Finlay, C M

    1996-01-01

    In order to determine the impact of the educational campaign about cholera on the knowledge and believes of the population, a survey was made in 1993 among 1324 persons from 14 provinces and from Isla de la Juventud special municipality. 85% were 20-59 years old and 89% had an secondary basic or higher educational level. 69% had the minimum knowledge to face the disease, 90% would see a doctor if they had and suspicion, 72% knew that diarrhea is the main symptom of cholera, 54% new how it is transmitted 89% thought that they may be infected by drinking water, 54% understood the importance of giving liquids to the sick subject, and 78% realized the significance of washing their hands before eating anf cooking. It is concluded that even though our population has a general knowledge about the disease, due to the fact that our country is located in an endemic zone, health education must be reinforced, specifically those aspects connected with the communication and with the increase of liquids administration to the patients.

  7. Methods to assess the impact of mass oral cholera vaccination campaigns under real field conditions.

    Directory of Open Access Journals (Sweden)

    Jacqueline Deen

    Full Text Available There is increasing interest to use oral cholera vaccination as an additional strategy to water and sanitation interventions against endemic and epidemic cholera. There are two internationally-available and WHO-prequalified oral cholera vaccines: an inactivated vaccine containing killed whole-cells of V. cholerae O1 with recombinant cholera toxin B-subunit (WC/rBS and a bivalent inactivated vaccine containing killed whole cells of V. cholerae O1 and V. cholerae O139 (BivWC. The efficacy, effectiveness, direct and indirect (herd protection conferred by WC/rBS and BivWC are well established. Yet governments may need local evidence of vaccine impact to justify and scale-up mass oral cholera vaccination campaigns. We discuss various approaches to assess oral cholera vaccine protection, which may be useful to policymakers and public health workers considering deployment and evaluation of the vaccine.

  8. Construction and evaluation of V. cholerae O139 mutant, VCUSM21P, as a safe live attenuated cholera vaccine.

    Science.gov (United States)

    Murugaiah, Chandrika; Nik Mohd Noor, Nik Zuraina; Mustafa, Shyamoli; Manickam, Ravichandran; Pattabhiraman, Lalitha

    2014-01-01

    Cholera is a major infectious disease, affecting millions of lives annually. In endemic areas, implementation of vaccination strategy against cholera is vital. As the use of safer live vaccine that can induce protective immunity against Vibrio cholerae O139 infection is a promising approach for immunization, we have designed VCUSM21P, an oral cholera vaccine candidate, which has ctxA that encodes A subunit of ctx and mutated rtxA/C, ace and zot mutations. VCUSM21P was found not to disassemble the actin of HEp2 cells. It colonized the mice intestine approximately 1 log lower than that of the Wild Type (WT) strain obtained from Hospital Universiti Sains Malaysia. In the ileal loop assay, unlike WT challenge, 1×10⁶ and 1×10⁸ colony forming unit (CFU) of VCUSM21P was not reactogenic in non-immunized rabbits. Whereas, the reactogenicity caused by the WT in rabbits immunized with 1×10¹⁰ CFU of VCUSM21P was found to be reduced as evidenced by absence of fluid in loops administered with 1×10²-1×10⁷ CFU of WT. Oral immunization using 1×10¹⁰ CFU of VCUSM21P induced both IgA and IgG against Cholera Toxin (CT) and O139 lipopolysaccharides (LPS). The serum vibriocidal antibody titer had a peak rise of 2560 fold on week 4. Following Removable Intestinal Tie Adult Rabbit Diarrhoea (RITARD) experiment, the non-immunized rabbits were found not to be protected against lethal challenge with 1×10⁹ CFU WT, but 100% of immunized rabbits survived the challenge. In the past eleven years, V. cholerae O139 induced cholera has not been observed. However, attenuated VCUSM21P vaccine could be used for vaccination program against potentially fatal endemic or emerging cholera caused by V. cholerae O139.

  9. The cholesterol-dependent cytolysin signature motif: a critical element in the allosteric pathway that couples membrane binding to pore assembly.

    Directory of Open Access Journals (Sweden)

    Kelley J Dowd

    Full Text Available The cholesterol-dependent cytolysins (CDCs constitute a family of pore-forming toxins that contribute to the pathogenesis of a large number of Gram-positive bacterial pathogens.The most highly conserved region in the primary structure of the CDCs is the signature undecapeptide sequence (ECTGLAWEWWR. The CDC pore forming mechanism is highly sensitive to changes in its structure, yet its contribution to the molecular mechanism of the CDCs has remained enigmatic. Using a combination of fluorescence spectroscopic methods we provide evidence that shows the undecapeptide motif of the archetype CDC, perfringolysin O (PFO, is a key structural element in the allosteric coupling of the cholesterol-mediated membrane binding in domain 4 (D4 to distal structural changes in domain 3 (D3 that are required for the formation of the oligomeric pore complex. Loss of the undecapeptide function prevents all measurable D3 structural transitions, the intermolecular interaction of membrane bound monomers and the assembly of the oligomeric pore complex. We further show that this pathway does not exist in intermedilysin (ILY, a CDC that exhibits a divergent undecapeptide and that has evolved to use human CD59 rather than cholesterol as its receptor. These studies show for the first time that the undecapeptide of the cholesterol-binding CDCs forms a critical element of the allosteric pathway that controls the assembly of the pore complex.

  10. Negatively charged residues of the segment linking the enzyme and cytolysin moieties restrict the membrane-permeabilizing capacity of adenylate cyclase toxin

    Science.gov (United States)

    Masin, Jiri; Osickova, Adriana; Sukova, Anna; Fiser, Radovan; Halada, Petr; Bumba, Ladislav; Linhartova, Irena; Osicka, Radim; Sebo, Peter

    2016-01-01

    The whooping cough agent, Bordetella pertussis, secretes an adenylate cyclase toxin-hemolysin (CyaA) that plays a crucial role in host respiratory tract colonization. CyaA targets CR3-expressing cells and disrupts their bactericidal functions by delivering into their cytosol an adenylate cyclase enzyme that converts intracellular ATP to cAMP. In parallel, the hydrophobic domain of CyaA forms cation-selective pores that permeabilize cell membrane. The invasive AC and pore-forming domains of CyaA are linked by a segment that is unique in the RTX cytolysin family. We used mass spectrometry and circular dichroism to show that the linker segment forms α-helical structures that penetrate into lipid bilayer. Replacement of the positively charged arginine residues, proposed to be involved in target membrane destabilization by the linker segment, reduced the capacity of the toxin to translocate the AC domain across cell membrane. Substitutions of negatively charged residues then revealed that two clusters of negative charges within the linker segment control the size and the propensity of CyaA pore formation, thereby restricting the cell-permeabilizing capacity of CyaA. The ‘AC to Hly-linking segment’ thus appears to account for the smaller size and modest cell-permeabilizing capacity of CyaA pores, as compared to typical RTX hemolysins. PMID:27581058

  11. Cholera toxin expression by El Tor Vibrio cholerae in shallow culture growth conditions.

    Science.gov (United States)

    Cobaxin, Mayra; Martínez, Haydee; Ayala, Guadalupe; Holmgren, Jan; Sjöling, Asa; Sánchez, Joaquín

    2014-01-01

    Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions.

  12. Cholera in Haiti: Reproductive numbers and vaccination coverage estimates

    Science.gov (United States)

    Mukandavire, Zindoga; Smith, David L.; Morris, J. Glenn, Jr.

    2013-01-01

    Cholera reappeared in Haiti in October, 2010 after decades of absence. Cases were first detected in Artibonite region and in the ensuing months the disease spread to every department in the country. The rate of increase in the number of cases at the start of epidemics provides valuable information about the basic reproductive number (). Quantitative analysis of such data gives useful information for planning and evaluating disease control interventions, including vaccination. Using a mathematical model, we fitted data on the cumulative number of reported hospitalized cholera cases in Haiti. varied by department, ranging from 1.06 to 2.63. At a national level, 46% vaccination coverage would result in an () debate on the use of cholera vaccines in endemic and non-endemic regions, our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti.

  13. Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

    Directory of Open Access Journals (Sweden)

    Keegan J. Baldauf

    2015-03-01

    Full Text Available Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT, which consists of two subunits: the A subunit (CTA and the B subunit (CTB. CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  14. Survival of Vibrio cholerae O1 on fomites

    DEFF Research Database (Denmark)

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

    2016-01-01

    It is well established that the contamination sources of cholera causing bacteria, Vibrio cholerae, are water and food, but little is known about the transmission role of the fomites (surfaces that can carry pathogens) commonly used in households. In the absence of appropriate nutrients or growth...... conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass......, plastic, cloth and several types of metals under laboratory conditions. The fomites were inoculated with an outbreak strain of V. cholerae and its culturability was examined by drop plate count method at 30 min intervals for up to 6 h. For molecular detection, the viable/dead stain ethidium monoazide (EMA...

  15. Cholera toxin B: one subunit with many pharmaceutical applications.

    Science.gov (United States)

    Baldauf, Keegan J; Royal, Joshua M; Hamorsky, Krystal Teasley; Matoba, Nobuyuki

    2015-03-20

    Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB). CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  16. Cholera Outbreak in Grande Comore: 1998–1999

    Science.gov (United States)

    Troeger, Christopher; Gaudart, Jean; Truillet, Romain; Sallah, Kankoe; Chao, Dennis L.; Piarroux, Renaud

    2016-01-01

    In 1998, a cholera epidemic in east Africa reached the Comoros Islands, an archipelago in the Mozambique Channel that had not reported a cholera case for more than 20 years. In just a little over 1 year (between January 1998 and March 1999), Grande Comore, the largest island in the Union of the Comoros, reported 7,851 cases of cholera, about 3% of the population. Using case reports and field observations during the medical response, we describe the epidemiology of the 1998–1999 cholera epidemic in Grande Comore. Outbreaks of infectious diseases on islands provide a unique opportunity to study transmission dynamics in a nearly closed population, and they may serve as stepping-stones for human pathogens to cross unpopulated expanses of ocean. PMID:26572869

  17. The Zymovars of Vibrio cholerae: Multilocus Enzyme Electrophoresis of Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Fernanda S Freitas

    2002-06-01

    Full Text Available Zymovars analysis also known as multilocus enzyme electrophoresis is applied here to investigate the genetic variation of Vibrio cholerae strains and characterise strains or group of strains of medical and epidemiological interest. Fourteen loci were analyzed in 171 strains of non-O1 non-O139, 32 classical and 61 El Tor from America, Africa, Europe and Asia. The mean genetic diversity was 0.339. It is shown that the same O antigen (both O1 and non-O1 may be present in several geneticaly diverse (different zymovars strains. Conversely the same zymovar may contain more than one serogroup. It is confirmed that the South American epidemic strain differs from the 7th pandemic El Tor strain in locus LAP (leucyl leucyl aminopeptidase. Here it is shown that this rare allele is present in 1 V. mimicus and 4 non-O1 V. cholerae. Non toxigenic O1 strains from South India epidemic share zymovar 14A with the epidemic El Tor from the 7th pandemic, while another group have diverse zymovars. The sucrose negative epidemic strains isolated in French Guiana and Brazil have the same zymovar of the current American epidemic V. cholerae.

  18. Hydroclimatic Extremes and Cholera Dynamics in the 21st Century

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Islam, S.

    2012-12-01

    Cholera, an acute water-borne diarrheal illness, has reemerged as a significant health threat across much of the developing world. Despite major advances in the ecological and the microbiological understanding of the causative agent, V. cholerae, the role of the underlying climatic and environmental processes in propagating transmission is not adequately understood. Recent findings suggest a more prominent role of hydroclimatic extremes - droughts and floods - on the unique dual cholera peaks in the Bengal Delta region of South Asia, the native homeland of cholera. Increasing water scarcity and abundance, and coastal sea-level rise, influenced by changing climate patterns and large-scale climatic phenomena, is likely to adversely impact cholera transmission in South Asia. We focus on understanding how associated changes in macro-scale conditions in this region will impact micro-scale processes related to cholera in coming decades. We use the PRECIS Regional Climate Model over the Ganges-Brahmaputra-Meghna (GBM) basin region to simulate detailed high resolution projections of climate patterns for the 21st century. Precipitation outputs are analyzed for the 1980-2040 period to identify the trends and changes in hydroclimatic extremes and potential impacts on cholera dynamics over the next three decades (2010-2040), in relation to the cholera surveillance operations over the past three decades (1980-2010). We find that an increased number of extreme precipitation events with prolonged dry periods in the Ganges basin region will likely adversely affect dry season cholera outbreaks. Increased monsoon precipitation volumes in the Brahmaputra basin catchments are likely to cause record floods and subsequently trigger large epidemics in downstream areas. Our results provide new insight by identifying the changes in the two distinctly different, pre and post monsoon, cholera transmission mechanisms related to large-scale climatic controls that prevail in the region. A

  19. The Role of Cyanobacteria Blooms in Cholera Epidemic in Bangladesh

    Science.gov (United States)

    Sagir Ahmed, Md.; Raknuzzaman, Md.; Akther, Hafeza; Ahmed, Sumaiya

    A study was conducted on association of Vibrio cholerae with plankton specially emphasis on cyanobacteria in relation to some physico-chemical parameters in the River Buriganga, Dhaka, from January to December 2002. Monthly abundance of phytoplankton and zooplankton varied from 457 to 14166 and from 169 to 1055 individual L-1, respectively. Monthly average of faecal coliform in water, zooplankton and phytoplankton samples were 3.99x109, 4.54x103 and 4.28x102 (CFU L-1), respectively. During epidemics, toxigenic V. cholerae 01 and 0139 were isolated from the patients as well as from the surface water. V. cholerae 01 and 0139 were also isolated from plankton samples. More over, it was observed that ctx (cholera toxic) positive in water and phytoplankton samples of the river. A bloom of Oscillatoria sp. (1.6x104 individual L-1) occurred in the upper reaches of the River Buriganga in May 2002. Methanol-water extract of bloom sample was analyzed by high performance liquid chromatography with UV detection and Mass Spectrum (MS) detected microcystin-RR. Cyanobacteria are abundant in the aquatic environment of Bangladesh and it was established that V. cholerae maintain a symbiotic relationship with these algae particularly mucilaginous cyanobacteria. During epidemics, patients symptoms included diarrhea, vomiting and hemorrhagic enteritis and in severe cases hemorrhagic diarrhea. So, question has arisen that which is responsible, microcystins or cholera for death of cholera/diarrhea patients in Bangladesh. Future research should be directed to isolate microcystins and cholera toxins from the epidemic areas to clarify the fact.

  20. Transcript changes in Vibrio cholerae in response to salt stress.

    Science.gov (United States)

    Fu, Xiuping; Liang, Weili; Du, Pengcheng; Yan, Meiying; Kan, Biao

    2014-01-01

    Vibrio cholerae, which is a serious human intestinal pathogen, often resides and thrives in estuaries but requires major self-regulation to overcome intestinal hyperosmotic stress or high salt stress in water and food. In the present study, we selected multiple O1 and O139 group V. cholerae strains that were isolated from different regions and during different years to study their salt tolerance. Based on the mechanisms that other bacteria use to respond to high salt stress, we selected salt stress-response related genes to study the mechanisms which V. cholerae responds to high salt stress. V. cholerae strains showed salt-resistance characteristics that varied in salt concentrations from 4% to 6%. However, group O1 and group O139 showed no significant difference in the degree of salt tolerance. The primary responses of bacteria to salt stress, including Na(+) exclusion, K(+) uptake and glutamate biosynthesis, were observed in V. cholerae strains. In addition, some sigma factors were up-regulated in V. cholerae strains, suggesting that V. cholerae may recruit common sigma factors to achieve an active salt stress response. However, some changes in gene transcript levels in response to salt stress in V. cholerae were strain-specific. In particular, hierarchical clustering of differentially expressed genes indicated that transcript levels of these genes were correlated with the degree of salt tolerance. Therefore, elevated transcript levels of some genes, including sigma factors and genes involved in peptidoglycan biosynthesis, may be due to the salt tolerance of strains. In addition, high salt-tolerant strains may recruit common as well as additional sigma factors to activate the salt stress response.

  1. Virulenzregulationskaskade und Chitobiose-Metabolismus in Vibrio cholerae

    OpenAIRE

    Berg, Thorsten

    2008-01-01

    Vibrio cholerae, der Erreger der gastrointestinalen Erkrankung Cholera, ist ein Gram- negatives, fakultativ anaerobes gekrümmtes Stäbchenbakterium und zugleich der wohl bekannteste Vertreter der Familie Vibrionaceae. Es persisitiert die meiste Zeit in aquatischen Ökosystemen wie Flüssen, Seen oder Meeresküsten, wo das Bakterium meist mit Crustaceen oder anderen Organismen mit Chitin-haltigen Oberflächen assoziiert vorliegt. Über orale Aufnahme kontaminierter Lebensmittel oder von Wasser kann ...

  2. Community health facility preparedness for a cholera surge in Haiti.

    Science.gov (United States)

    Mobula, Linda Meta; Jacquet, Gabrielle A; Weinhauer, Kristin; Alcidas, Gladys; Thomas, Hans-Muller; Burnham, Gilbert

    2013-01-01

    With increasing population displacement and worsening water insecurity after the 2010 earthquake, Haiti experienced a large cholera outbreak. Our goal was to evaluate the strengths and weaknesses of seven community health facilities' ability to respond to a surge in cholera cases. Since 2010, Catholic Relief Services (CRS) with a number of public and private donors has been working with seven health facilities in an effort to reduce morbidity and mortality from cholera infection. In November 2012, CRS through the Centers for Disease Control and Prevention (CDC)'s support, asked the Johns Hopkins Center for Refugee and Disaster Response to conduct a cholera surge simulation tabletop exercise at these health facilities to improve each facility's response in the event of a cholera surge. Using simulation development guidelines from the Pan American Health Organization and others, a simulation scenario script was produced that included situations of differing severity, supply chain, as well as a surge of patients. A total of 119 hospital staff from seven sites participated in the simulation exercise including community health workers, clinicians, managers, pharmacists, cleaners, and security guards. Clinics that had challenges during the simulated clinical care of patients were those that did not appropriately treat all cholera patients according to protocol, particularly those that were vulnerable, those that would need additional staff to properly treat patients during a surge of cholera, and those that required a better inventory of supplies. Simulation-based activities have the potential to identify healthcare delivery system vulnerabilities that are amenable to intervention prior to a cholera surge.

  3. Chromosome segregation proteins of Vibrio cholerae as transcription regulators.

    Science.gov (United States)

    Baek, Jong Hwan; Rajagopala, Seesandra V; Chattoraj, Dhruba K

    2014-05-06

    ABSTRACT Bacterial ParA and ParB proteins are best known for their contribution to plasmid and chromosome segregation, but they may also contribute to other cell functions. In segregation, ParA interacts with ParB, which binds to parS centromere-analogous sites. In transcription, plasmid Par proteins can serve as repressors by specifically binding to their own promoters and, additionally, in the case of ParB, by spreading from a parS site to nearby promoters. Here, we have asked whether chromosomal Par proteins can likewise control transcription. Analysis of genome-wide ParB1 binding in Vibrio cholerae revealed preferential binding to the three known parS1 sites and limited spreading of ParB1 beyond the parS1 sites. Comparison of wild-type transcriptomes with those of ΔparA1, ΔparB1, and ΔparAB1 mutants revealed that two out of 20 genes (VC0067 and VC0069) covered by ParB1 spreading are repressed by both ParB1 and ParA1. A third gene (VC0076) at the outskirts of the spreading area and a few genes further away were also repressed, particularly the gene for an outer membrane protein, ompU (VC0633). Since ParA1 or ParB1 binding was not evident near VC0076 and ompU genes, the repression may require participation of additional factors. Indeed, both ParA1 and ParB1 proteins were found to interact with several V. cholerae proteins in bacterial and yeast two-hybrid screens. These studies demonstrate that chromosomal Par proteins can repress genes unlinked to parS and can do so without direct binding to the cognate promoter DNA. IMPORTANCE Directed segregation of chromosomes is essential for their maintenance in dividing cells. Many bacteria have genes (par) that were thought to be dedicated to segregation based on analogy to their roles in plasmid maintenance. It is becoming clear that chromosomal par genes are pleiotropic and that they contribute to diverse processes such as DNA replication, cell division, cell growth, and motility. One way to explain the pleiotropy

  4. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    John Benktander

    Full Text Available The binding of cholera toxin to the ganglioside GM1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. In contrast, the knowledge about the mechanisms for attachment of Vibrio cholerae bacterial cells to the intestinal epithelium is limited. In order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of El Tor V. cholerae. Several specific interactions with minor complex non-acid glycosphingolipids were thereby detected. After isolation of binding-active glycosphingolipids, characterization by mass spectrometry and proton NMR, and comparative binding studies, three distinct glycosphingolipid binding patterns were defined. Firstly, V. cholerae bound to complex lacto/neolacto glycosphingolipids with the GlcNAcβ3Galβ4GlcNAc sequence as the minimal binding epitope. Secondly, glycosphingolipids with a terminal Galα3Galα3Gal moiety were recognized, and the third specificity was the binding to lactosylceramide and related compounds. V. cholerae binding to lacto/neolacto glycosphingolipids, and to the other classes of binding-active compounds, remained after deletion of the chitin binding protein GbpA. Thus, the binding of V. cholerae to chitin and to lacto/neolacto containing glycosphingolipids represents two separate binding specificities.

  5. Considerations around the introduction of a cholera vaccine in Bangladesh.

    Science.gov (United States)

    Nelson, Christopher B; Mogasale, Vittal; Bari, Tajul Islam A; Clemens, John D

    2014-12-12

    Cholera is an endemic and epidemic disease in Bangladesh. On 3 March 2013, a meeting on cholera and cholera vaccination in Bangladesh was convened by the Foundation Mérieux jointly with the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B). The purpose of the meeting was to discuss the investment case for cholera vaccination as a complimentary control and prevention strategy. The performance of a new low cost oral cholera vaccine, Shanchol™, used in recent trials in Bangladesh, was also reviewed in the context of a potential large-scale public-sector vaccination program. Findings showed the oral vaccine to be highly cost-effective when targeting ages 1-14 y, and cost-effective when targeting ages 1+y, in high-burden/high-risk districts. Other vaccination strategies targeting urban slums and rural areas without improved water were found to be cost-effective. Regardless of cost-effectiveness (value), the budget impact (affordability) will be an important determinant of which target population and vaccination strategy is selected. Most importantly, adequate vaccine supply for the proposed vaccination programs must be addressed in the context of global efforts to establish a cholera vaccine stockpile and supply other control and prevention efforts.

  6. [Cholera in Europe and Denmark in the 19th century].

    Science.gov (United States)

    Bonderup, G

    1996-01-01

    There are several reasons for dealing with cholera in the 19th century: it acted as a spotlight throwing into sharp relief the darkest corners of society that are seldom mentioned in the sources. We learn about everyday life in large parts of the population, especially the poor. The fight against the disease also reveals how a society worked socially and politically. When cholera arrived in Europe -- the first time was in the 1830's and several times after that--the population reacted very violently, often by lynching doctors, while the authorities more or less let matters take their course. That is why international researchers have come to see cholera as a catalyst for the constantly latent social unrest following in the train of wars and revolutions. During my research on cholera in Denmark it became clear to me that matters were different here. There were no riots, nor any signs of social unrest--neither before nor after the outbreak of cholera. On the contrary, the authorities and the population joined forces against the epidemic. There was an atmosphere of mutual trust, and almost everybody turned out to be worthy of such trust. That points to a balanced society based on consensus, so cholera also functions as a detector of the fundamental structure of a society.

  7. Epidemiology, determinants and dynamics of cholera in Pakistan: gaps and prospects for future research.

    Science.gov (United States)

    Naseer, Maliha; Jamali, Tanzil

    2014-11-01

    Cholera is one of the notifiable endemic diseases in Pakistan, but the reporting of cholera cases is still unsatisfactory. Most of the diagnosed cases are never reported to the relevant authorities. In the year 1993 - 2005, the country did not report any single case of cholera to the WHO. The objectives of this review were to understand the epidemiology and to identify the possible determinants of cholera infection in Pakistan. Medscape, Medline, PakMedinet and PubMed, was searched, using key words, epidemiology and determinants of cholera infection in Pakistan during 1995 - 2010. Morbidity and mortality due to cholera infection during 1995 - 2010, without any language restriction. Out of 27 articles published between 1995 - 2010, 17 articles were included in the review. Vibrio cholerae O139 identified as a major cause of infection in older age group, while O1 biotype of cholera as a predominant cause of cholera among young individuals. Mainly reported determinants of cholera in Pakistan include poor sanitation and hygiene practices, increased population density in urban areas, leading to rapid and unplanned urbanization of the major cities and climate change due to increased environmental pollution in Pakistan are plausible factors for endemicity of cholera in Pakistan. Cholera reporting as a notifiable disease to the relevant departments and timely action can prevent the risk of outbreaks. There is a need to identify specific behavioral and environmental determinants responsible for outbreaks and epidemics of cholera in Pakistan which can help to design appropriate preventive and control interventions.

  8. Hybrid microarray based on double biomolecular markers of DNA and carbohydrate for simultaneous genotypic and phenotypic detection of cholera toxin-producing Vibrio cholerae.

    Science.gov (United States)

    Shin, Hwa Hui; Seo, Jeong Hyun; Kim, Chang Sup; Hwang, Byeong Hee; Cha, Hyung Joon

    2016-05-15

    Life-threatening diarrheal cholera is usually caused by water or food contaminated with cholera toxin-producing Vibrio cholerae. For the prevention and surveillance of cholera, it is crucial to rapidly and precisely detect and identify the etiological causes, such as V. cholerae and/or its toxin. In the present work, we propose the use of a hybrid double biomolecular marker (DBM) microarray containing 16S rRNA-based DNA capture probe to genotypically identify V. cholerae and GM1 pentasaccharide capture probe to phenotypically detect cholera toxin. We employed a simple sample preparation method to directly obtain genomic DNA and secreted cholera toxin as target materials from bacterial cells. By utilizing the constructed DBM microarray and prepared samples, V. cholerae and cholera toxin were detected successfully, selectively, and simultaneously; the DBM microarray was able to analyze the pathogenicity of the identified V. cholerae regardless of whether the bacteria produces toxin. Therefore, our proposed DBM microarray is a new effective platform for identifying bacteria and analyzing bacterial pathogenicity simultaneously.

  9. Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

    Directory of Open Access Journals (Sweden)

    Luque Fernandez Miguel A

    2012-06-01

    Full Text Available Abstract Background In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. Methods We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. Results This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76. Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. Conclusion This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive

  10. Molecular Epidemiology and Antibiotic Susceptibility of Vibrio cholerae Associated with a Large Cholera Outbreak in Ghana in 2014.

    Directory of Open Access Journals (Sweden)

    Daniel Eibach

    2016-05-01

    Full Text Available Ghana is affected by regular cholera epidemics and an annual average of 3,066 cases since 2000. In 2014, Ghana experienced one of its largest cholera outbreaks within a decade with more than 20,000 notified infections. In order to attribute this rise in cases to a newly emerging strain or to multiple simultaneous outbreaks involving multi-clonal strains, outbreak isolates were characterized, subtyped and compared to previous epidemics in 2011 and 2012.Serotypes, biotypes, antibiotic susceptibilities were determined for 92 Vibrio cholerae isolates collected in 2011, 2012 and 2014 from Southern Ghana. For a subgroup of 45 isolates pulsed-field gel electrophoresis, multilocus sequence typing and multilocus-variable tandem repeat analysis (MLVA were performed. Eighty-nine isolates (97% were identified as ctxB (classical type positive V. cholerae O1 biotype El Tor and three (3% isolates were cholera toxin negative non-O1/non-O139 V. cholerae. Among the selected isolates only sulfamethoxazole/trimethoprim resistance was detectable in 2011, while 95% of all 2014 isolates showed resistance towards sulfamethoxazole/trimethoprim, ampicillin and reduced susceptibility to ciprofloxacin. MLVA achieved the highest subtype discrimination, revealing 22 genotypes with one major outbreak cluster in each of the three outbreak years. Apart from those clusters genetically distant genotypes circulate during each annual epidemic.This analysis suggests different endemic reservoirs of V. cholerae in Ghana with distinct annual outbreak clusters accompanied by the occurrence of genetically distant genotypes. Preventive measures for cholera transmission should focus on aquatic reservoirs. Rapidly emerging multidrug resistance must be monitored closely.

  11. Characterization of tryptophanase from Vibrio cholerae.

    Science.gov (United States)

    Nuidate, Taiyeebah; Tansila, Natta; Chomchuen, Piraporn; Phattaranit, Phattiphong; Eangchuan, Supachok; Vuddhakul, Varaporn

    2015-01-01

    Tryptophanase (Trpase) is a pyridoxal phosphate (PLP)-dependent enzyme responsible for the production of indole, an important intra- and interspecies signaling molecule in bacteria. In this study, the tnaA gene of Vibrio cholerae coding for VcTrpase was cloned into the pET-20b(+) vector and expressed in Escherichia coli BL21(DE3) tn5:tnaA. Using Ni(2+)-nitrilotriacetic acid (NTA) chromatography, VcTrpase was purified, and it possessed a molecular mass of ∼49 kDa with specific absorption peaks at 330 and 435 nm and a specific activity of 3 U/mg protein. The VcTrpase had an 80 % homology to the Trpase of Haemophilus influenzae and E. coli, but only around 50 % identity to the Trpase of Proteus vulgaris and Porphyromonas gingivalis. The optimum conditions for the enzyme were at pH 9.0 and 45 °C. Recombinant VcTrpase exhibited analogous kinetic reactivity to the EcTrpase with K m and k cat values of 0.612 × 10(-3) M and 5.252 s(-1), respectively. The enzyme catalyzed S-methyl-L-cysteine and S-benzyl-L-cysteine degradation, but not L-phenylalanine and L-serine. Using a site-directed mutagenesis technique, eight residues (Thr52, Tyr74, Arg103, Asp137, Arg230, Lys269, Lys270, and His463) were conserved for maintaining enzyme catalysis. All amino acid substitutions at these sites either eliminated or remarkably diminished Trpase activity. These sites are thus potential targets for the design of drugs to control the V. cholerae Trpase and to further investigate its functions.

  12. Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country

    Directory of Open Access Journals (Sweden)

    Yan Boucher

    2016-07-01

    Full Text Available Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15. It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae.

  13. Breast milk reduces the risk of illness in children of mothers with cholera

    DEFF Research Database (Denmark)

    Qureshi, Katja; Mølbak, Kåre; Sandström, Anita

    2006-01-01

    BACKGROUND: A protective effect of breastfeeding against cholera has been demonstrated in areas endemic of cholera. To assess the protection offered by breast milk from mothers living in an area that had been free from cholera for 7 years, we investigated mothers with cholera and their children...... during an epidemic with Vibrio cholerae El Tor in the capital of Guinea-Bissau. METHODS: Eighty mothers with clinical cholera and their children were identified, and interviewed. Blood samples for vibriocidal and antitoxin antibodies were collected from mother-and-child pairs. Breast milk samples were...... collected from lactating mothers.Cholera was defined as acute watery diarrhea during the epidemic and a vibriocidal reciprocal titer of 20 or above. RESULTS: Three (7%) of 42 breastfed children had cholera as defined above compared with 9 (24%) of 38 nonbreastfed children (RR for breastfed children, 0...

  14. Monitoring water sources for environmental reservoirs of toxigenic Vibrio cholerae O1, Haiti.

    Science.gov (United States)

    Alam, Meer T; Weppelmann, Thomas A; Weber, Chad D; Johnson, Judith A; Rashid, Mohammad H; Birch, Catherine S; Brumback, Babette A; Beau de Rochars, Valery E Madsen; Morris, J Glenn; Ali, Afsar

    2014-03-01

    An epidemic of cholera infections was documented in Haiti for the first time in more than 100 years during October 2010. Cases have continued to occur, raising the question of whether the microorganism has established environmental reservoirs in Haiti. We monitored 14 environmental sites near the towns of Gressier and Leogane during April 2012-March 2013. Toxigenic Vibrio cholerae O1 El Tor biotype strains were isolated from 3 (1.7%) of 179 water samples; nontoxigenic O1 V. cholerae was isolated from an additional 3 samples. All samples containing V. cholerae O1 also contained non-O1 V. cholerae. V. cholerae O1 was isolated only when water temperatures were ≥31°C. Our data substantiate the presence of toxigenic V. cholerae O1 in the aquatic environment in Haiti. These isolations may reflect establishment of long-term environmental reservoirs in Haiti, which may complicate eradication of cholera from this coastal country.

  15. Soluble Oligomers of the Pore-forming Toxin Cytolysin A from Escherichia coli Are Off-pathway Products of Pore Assembly.

    Science.gov (United States)

    Roderer, Daniel; Benke, Stephan; Schuler, Benjamin; Glockshuber, Rudi

    2016-03-11

    The α-pore-forming toxin Cytolysin A (ClyA) is responsible for the hemolytic activity of various Escherichia coli and Salmonella enterica strains. Soluble ClyA monomers spontaneously assemble into annular dodecameric pore complexes upon contact with membranes or detergent. At ClyA monomer concentrations above ∼100 nm, the rate-limiting step in detergent- or membrane- induced pore assembly is the unimolecular reaction from the monomer to the assembly-competent protomer, which then oligomerizes rapidly to active pore complexes. In the absence of detergent, ClyA slowly forms soluble oligomers. Here we show that soluble ClyA oligomers cannot form dodecameric pore complexes after the addition of detergent and are hemolytically inactive. In addition, we demonstrate that the natural cysteine pair Cys-87/Cys-285 of ClyA forms a disulfide bond under oxidizing conditions and that both the oxidized and reduced ClyA monomers assemble to active pores via the same pathway in the presence of detergent, in which an unstructured, monomeric intermediate is transiently populated. The results show that the oxidized ClyA monomer assembles to pore complexes about one order of magnitude faster than the reduced monomer because the unstructured intermediate of oxidized ClyA is less stable and dissolves more rapidly than the reduced intermediate. Moreover, we show that oxidized ClyA forms soluble, inactive oligomers in the absence of detergent much faster than the reduced monomer, providing an explanation for several contradictory reports in which oxidized ClyA had been described as inactive.

  16. The Solvent-Exposed C-Terminus of the Cytolysin A Pore-Forming Toxin Directs Pore Formation and Channel Function in Membranes.

    Science.gov (United States)

    Sathyanarayana, Pradeep; Desikan, Rajat; Ayappa, K Ganapathy; Visweswariah, Sandhya S

    2016-10-13

    Pore-forming toxins (PFTs) bind to cell membranes and form nanoscale pores that allow leakage of cellular components, resulting in cell death. The water-soluble, monomeric form of these toxins shows a dramatic conformational change during pore formation, as exemplified by crystal structures of the monomer and functional pore of cytolysin A (ClyA). The solvent-exposed, C-terminal residues of the protein are essential for activity, but the mechanism by which this region regulates pore formation remains unknown. We show here that deletion of the C-terminus of ClyA did not alter its ability to bind to the membrane or oligomerize in detergent. However, the truncated toxin lysed erythrocytes poorly, was more susceptible to proteolysis and thermal unfolding, and showed low calcein leakage from small unilamellar vesicles. Using fully atomistic molecular dynamics (MD) simulations, we find that deletion of C-terminal residues from the ClyA monomer significantly altered stability and unfolding trajectories in the transmembrane N-terminal helix, a region that is pivotal in maintaining the structural integrity of the helical bundle. MD simulations of pores with or without the C-terminus showed minor differences, implying that if oligomerization could be induced prior to the addition to vesicles, then an active pore could be generated. Via generation of oligomers in a detergent prior to the addition to vesicles, the truncated toxin could induce calcein leakage from vesicles, albeit to a lower extent. Therefore, regions of pore-forming toxins, not directly involved in the pore structure, are not passive players but have important roles in undergoing the transition through intermediary steps leading to successful pore formation in a membrane environment.

  17. Changes in Astrocyte Shape Induced by Sublytic Concentrations of the Cholesterol-Dependent Cytolysin Pneumolysin Still Require Pore-Forming Capacity

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    Christina Förtsch

    2011-01-01

    Full Text Available Streptococcus pneumoniae is a common pathogen that causes various infections, such as sepsis and meningitis. A major pathogenic factor of S. pneumoniae is the cholesterol-dependent cytolysin, pneumolysin. It produces cell lysis at high concentrations and apoptosis at lower concentrations. We have shown that sublytic amounts of pneumolysin induce small GTPase-dependent actin cytoskeleton reorganization and microtubule stabilization in human neuroblastoma cells that are manifested by cell retraction and changes in cell shape. In this study, we utilized a live imaging approach to analyze the role of pneumolysin’s pore-forming capacity in the actin-dependent cell shape changes in primary astrocytes. After the initial challenge with the wild-type toxin, a permeabilized cell population was rapidly established within 20–40 minutes. After the initial rapid permeabilization, the size of the permeabilized population remained unchanged and reached a plateau. Thus, we analyzed the non-permeabilized (non-lytic population, which demonstrated retraction and shape changes that were inhibited by actin depolymerization. Despite the non-lytic nature of pneumolysin treatment, the toxin’s lytic capacity remained critical for the initiation of cell shape changes. The non-lytic pneumolysin mutants W433F-pneumolysin and delta6-pneumolysin, which bind the cell membrane with affinities similar to that of the wild-type toxin, were not able to induce shape changes. The initiation of cell shape changes and cell retraction by the wild-type toxin were independent of calcium and sodium influx and membrane depolarization, which are known to occur following cellular challenge and suggested to result from the ion channel-like properties of the pneumolysin pores. Excluding the major pore-related phenomena as the initiation mechanism of cell shape changes, the existence of a more complex relationship between the pore-forming capacity of pneumolysin and the actin cytoskeleton

  18. Time series analysis of cholera in Matlab, Bangladesh, during 1988-2001.

    Science.gov (United States)

    Ali, Mohammad; Kim, Deok Ryun; Yunus, Mohammad; Emch, Michael

    2013-03-01

    The study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of Bangladesh and developed a forecasting model for understanding the magnitude of incidence. Diarrhoea surveillance data collected between 1988 and 2001 were obtained from a field research site in Matlab, Bangladesh. Cholera cases were defined as Vibrio cholerae O1 isolated from faecal specimens of patients who sought care at treatment centres serving the Matlab population. Cholera incidence for 168 months was correlated with remotely-sensed sea-surface temperature (SST) and in-situ environmental data, including rainfall and ambient temperature. A seasonal autoregressive integrated moving average (SARIMA) model was used for determining the impact of climatic and environmental variability on cholera incidence and evaluating the ability of the model to forecast the magnitude of cholera. There were 4,157 cholera cases during the study period, with an average of 1.4 cases per 1,000 people. Since monthly cholera cases varied significantly by month, it was necessary to stabilize the variance of cholera incidence by computing the natural logarithm to conduct the analysis. The SARIMA model shows temporal clustering of cholera at one- and 12-month lags. There was a 6% increase in cholera incidence with a minimum temperature increase of one degree celsius in the current month. For increase of SST by one degree celsius, there was a 25% increase in the cholera incidence at currrent month and 18% increase in the cholera incidence at two months. Rainfall did not influenc to cause variation in cholera incidence during the study period. The model forecast the fluctuation of cholera incidence in Matlab reasonably well (Root mean square error, RMSE: 0.108). Thus, the ambient and sea-surface temperature-based model could be used in forecasting cholera outbreaks in Matlab.

  19. Thapsigargin-induced transport of cholera toxin to the endoplasmic reticulum.

    OpenAIRE

    Sandvig, K.; Garred, O; van Deurs, B.

    1996-01-01

    Cholera toxin is normally observed only in the Golgi apparatus and not in the endoplasmic reticulum (ER) although the enzymatically active A subunit of cholera toxin has a KDEL sequence. Here we demonstrate transport of horseradish peroxidase-labeled cholera toxin to the ER by electron microscopy in thapsigargin-treated A431 cells. Thapsigargin treatment strongly increased cholera toxin-induced cAMP production, and the formation of the catalytically active A1 fragment was somewhat increased. ...

  20. Climate Variability and the Outbreaks of Cholera in Zanzibar, East Africa: A Time Series Analysis

    OpenAIRE

    Reyburn, Rita; Kim, Deok Ryun; Emch, Michael; Khatib, Ahmed; von Seidlein, Lorenz; Ali, Mohammad

    2011-01-01

    Global cholera incidence is increasing, particularly in sub-Saharan Africa. We examined the impact of climate and ocean environmental variability on cholera outbreaks, and developed a forecasting model for outbreaks in Zanzibar. Routine cholera surveillance reports between 1997 and 2006 were correlated with remotely and locally sensed environmental data. A seasonal autoregressive integrated moving average (SARIMA) model determined the impact of climate and environmental variability on cholera...

  1. [Cholera in 1831. Challenges for science and the federal government].

    Science.gov (United States)

    Stamm-Kuhlmann, T

    1989-01-01

    The peak of the first great cholera pandemic in 1831 fomented the controversy among contagionists and non-contagionists. In the following year the public debate centered around the correct interpretation of the recent experiences with cholera. The central government of the bureaucratic-absolutist monarchy in Prussia adhered to a firmly contagionist interpretation of the disease and reacted accordingly. Local authorities in Königsberg and Berlin and the bourgeoisie in the merchant city of Danzig, however, stressed the destructive consequences of the cordon system. They considered the results of an interruption in trade and industry to be worse than the damage inflicted by the epidemic. The summer of 1831 demonstrated that cholera could not be stopped by the cordons, but the King's medical advisors nevertheless remained contagionists. Non-contagionists put forward several hypotheses to explain the origin and the spreading of cholera, mainly "miasma" theory and the Hippocratic paradigm of "epidemic constitution". The correlation between poverty and disease, however, was widely noticed. Physicians in the city of Bremen pointed to the necessity of sanitary precautions to be taken in cholera-free periods. On the other hand, many "honest" citizens believed that individuals with a "dissolute" conduct of life were more at risk to contract cholera than others. Instead of costly sanitary policies, the well-to-do classes preferred to identify the defense against cholera with the segregation of unwelcome elements of society. The article is based on hitherto unpublished sources from the former Prussian State Archives at Merseburg, GDR, and the State Archive of the Hanseatic City of Bremen.

  2. Outbreak-associated Vibrio cholerae genotypes with identical pulsotypes, Malaysia, 2009.

    Science.gov (United States)

    Teh, Cindy Shuan Ju; Suhaili, Zarizal; Lim, King Ting; Khamaruddin, Muhamad Afif; Yahya, Fariha; Sajili, Mohd Hailmi; Yeo, Chew Chieng; Thong, Kwai Lin

    2012-07-01

    A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures.

  3. Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae

    DEFF Research Database (Denmark)

    Matz, Carsten; McDougald, D.; Moreno, A.M.

    2005-01-01

    Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces. Alt...

  4. A model to predict when a cholera outbreak might hit the Congo

    Science.gov (United States)

    Schultz, Colin

    2014-09-01

    In 2011, as many as 600,000 people in 58 countries contracted cholera, with thousands succumbing to the disease. In most countries, cholera is rare. In others, like the Democratic Republic of the Congo, cholera is an endemic threat, always lurking in the background waiting for the right set of conditions to spark an outbreak.

  5. Cholera in coastal Africa: a systematic review of its heterogeneous environmental determinants.

    Science.gov (United States)

    Rebaudet, Stanislas; Sudre, Bertrand; Faucher, Benoît; Piarroux, Renaud

    2013-11-01

    According to the "cholera paradigm," epidemiology of this prototypical waterborne disease is considered to be driven directly by climate-induced variations in coastal aquatic reservoirs of Vibrio cholerae. This systematic review on environmental determinants of cholera in coastal Africa shows that instead coastal epidemics constitute a minor part of the continental cholera burden. Most of coastal cholera foci are located near estuaries, lagoons, mangrove forests, and on islands. Yet outbreaks often originate in coastal cities, where cholera is more likely to be imported from distant areas. Cholera outbreaks also may intensify in densely populated slum quarters before spreading to adjacent regions. Frequent seasonality of cholera incidence appears driven by the rainfall-induced contamination of unprotected water sources through latrine overflow and sewage, as well as by the periodicity of human activities like fishing or traveling. Lulls in transmission periods of several years are repeatedly recorded even in high-risk coastal areas. To date, environmental studies have failed to demonstrate a perennial aquatic reservoir of toxigenic V. cholerae around the continent. Finally, applicability of the cholera paradigm therefore appears questionable in Africa, although available data remain limited. Thorough surveys with microbiological analyses of water samples and prospective genotyping of environmental and clinical strains of V. cholerae are needed to understand determinants of cholera in coastal Africa and better target prevention and control measures.

  6. Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

    Directory of Open Access Journals (Sweden)

    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.

  7. Non-01 Vibrio cholerae infections in Cancun, Mexico.

    Science.gov (United States)

    Finch, M J; Valdespino, J L; Wells, J G; Perez-Perez, G; Arjona, F; Sepulveda, A; Bessudo, D; Blake, P A

    1987-03-01

    To determine the role of Vibrio cholerae as a cause of diarrheal illness in Cancun, Mexico, an investigation was conducted in July and August 1983. Although toxigenic V. cholerae 01 were not found, non-01 V. cholerae were isolated from 22 (16%) of 134 stools from persons with diarrheal illness and none of 22 stools from well persons; 58 (92%) of 63 sewage samples; 12 (86%) of 14 untreated well water samples; a home storage tank for treated water; and 5 (21%) of 24 samples of raw seafood. None of the V. cholerae isolates from patients were toxigenic. The illness occurred mainly in small children, and were characterized principally by diarrhea and abdominal pain. No patient was seriously ill, and all recovered without sequelae. Seven different serotypes of non-01 V. cholerae were isolated from the stool specimens, and Smith serotype 12 accounted for 10 (46%) of the 22 isolates. A matched-pair case-control study found that cases were more likely than controls to have eaten home prepared gelatin (P = 0.03, OR = 5/0) and seafood (P = 0.06, OR = 4/0).

  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. On the probability of extinction of the Haiti cholera epidemic

    Science.gov (United States)

    Bertuzzo, Enrico; Finger, Flavio; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea

    2014-05-01

    Nearly 3 years after its appearance in Haiti, cholera has already exacted more than 8,200 deaths and 670,000 reported cases and it is feared to become endemic. However, no clear evidence of a stable environmental reservoir of pathogenic Vibrio cholerae, the infective agent of the disease, has emerged so far, suggesting that the transmission cycle of the disease is being maintained by bacteria freshly shed by infected individuals. Thus in principle cholera could possibly be eradicated from Haiti. Here, we develop a framework for the estimation of the probability of extinction of the epidemic based on current epidemiological dynamics and health-care practice. Cholera spreading is modelled by an individual-based spatially-explicit stochastic model that accounts for the dynamics of susceptible, infected and recovered individuals hosted in different local communities connected through hydrologic and human mobility networks. Our results indicate that the probability that the epidemic goes extinct before the end of 2016 is of the order of 1%. This low probability of extinction highlights the need for more targeted and effective interventions to possibly stop cholera in Haiti.

  10. Cyclo(valine-valine) inhibits Vibrio cholerae virulence gene expression.

    Science.gov (United States)

    Vikram, Amit; Ante, Vanessa M; Bina, X Renee; Zhu, Qin; Liu, Xinyu; Bina, James E

    2014-06-01

    Vibrio cholerae has been shown to produce a cyclic dipeptide, cyclo(phenylalanine-proline) (cFP), that functions to repress virulence factor production. The objective of this study was to determine if heterologous cyclic dipeptides could repress V. cholerae virulence factor production. To that end, three synthetic cyclic dipeptides that differed in their side chains from cFP were assayed for virulence inhibitory activity in V. cholerae. The results revealed that cyclo(valine-valine) (cVV) inhibited virulence factor production by a ToxR-dependent process that resulted in the repression of the virulence regulator aphA. cVV-dependent repression of aphA was found to be independent of known aphA regulatory genes. The results demonstrated that V. cholerae was able to respond to exogenous cyclic dipeptides and implicated the hydrophobic amino acid side chains on both arms of the cyclo dipeptide scaffold as structural requirements for inhibitory activity. The results further suggest that cyclic dipeptides have potential as therapeutics for cholera treatment.

  11. Isolation of isoelectrically pure cholera toxin for crystallization

    Science.gov (United States)

    Spangler, Brenda D.; Westbrook, Edwin M.

    1991-03-01

    We have determined that the failure of cholera toxin to crystallize well results from its isoelectric heterogeneity, which is probably due to a post-translational process such as deamidation of its B subunit. Every sample of cholera toxin we have examined from commercial or academic suppliers has been heterogeneous; heterogeneous cholera toxin does not crystallize satisfactorily. We have overcome this problem by using ion-exchange fast protein liquid chromatography (FPLC) to obtain an isoelectrically homogeneous species of cholera toxin. Homogeneous cholera toxin crystallizes readily, forming single, nonmosaic crystals suitable for X-ray diffraction studies. For this process, protein was applied to a MonoQ ion-exchange column, then eluted with an isocratic low salt buffer followed by a linear salt gradient (0-100 mM NaCl). Column fractions were analyzed on isoelectric focusing gels, and those fractions containing the desired homogeneous species were pooled and concentrated. Crystals formed within 24 to 48 h in a MOPS/PEG buffer, which made use of slow isoelectric precipitation to induce crystallization.

  12. RpoS plays a central role in the SOS induction by sub-lethal aminoglycoside concentrations in Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Zeynep Baharoglu

    Full Text Available Bacteria encounter sub-inhibitory concentrations of antibiotics in various niches, where these low doses play a key role for antibiotic resistance selection. However, the physiological effects of these sub-lethal concentrations and their observed connection to the cellular mechanisms generating genetic diversification are still poorly understood. It is known that, unlike for the model bacterium Escherichia coli, sub-minimal inhibitory concentrations (sub-MIC of aminoglycosides (AGs induce the SOS response in Vibrio cholerae. SOS is induced upon DNA damage, and since AGs do not directly target DNA, we addressed two issues in this study: how sub-MIC AGs induce SOS in V. cholerae and why they do not do so in E. coli. We found that when bacteria are grown with tobramycin at a concentration 100-fold below the MIC, intracellular reactive oxygen species strongly increase in V. cholerae but not in E. coli. Using flow cytometry and gfp fusions with the SOS regulated promoter of intIA, we followed AG-dependent SOS induction. Testing the different mutation repair pathways, we found that over-expression of the base excision repair (BER pathway protein MutY relieved this SOS induction in V. cholerae, suggesting a role for oxidized guanine in AG-mediated indirect DNA damage. As a corollary, we established that a BER pathway deficient E. coli strain induces SOS in response to sub-MIC AGs. We finally demonstrate that the RpoS general stress regulator prevents oxidative stress-mediated DNA damage formation in E. coli. We further show that AG-mediated SOS induction is conserved among the distantly related Gram negative pathogens Klebsiella pneumoniae and Photorhabdus luminescens, suggesting that E. coli is more of an exception than a paradigm for the physiological response to antibiotics sub-MIC.

  13. Replicating function of the RS1 element associated with Vibrio cholerae CTX phi prophage.

    Science.gov (United States)

    Campos, J; Fando, R; Silva, A; Rodriguez, B L; Benitez, J A

    1998-07-01

    The RS1 element associated with Vibrio cholerae CTX phi prophage was cloned from an E1 Tor biotype Vibrio cholerae strain. We used the recA- vaccine strain Peru-15, that lacks the target for RS-mediated site-specific integration, to show that RS1 promotes autonomous replication of a suicide vector. A linker insertion in the rstR open reading frame abolished autonomous replication in Peru-15 but not in a strain containing an RS1 in the chromosome. An AT-rich region containing cis-acting elements involved in autonomous replication was identified by deletion. This region was sufficient to support autonomous replication in a strain containing an RS1 in the chromosome. DNA sequence analysis of a region present in RS1 and not RS2 revealed the presence of putative binding sites for host proteins involved in plasmid replication. These results indicate that RS1 contains a replicon distinct from RS2 which could be involved in replicative recombination events associated with tandem amplification of the CTX element.

  14. The hows and whys of constructing a native recombinant cholera vaccine

    Science.gov (United States)

    Boustanshenas, Mina; Bakhshi, Bita

    2014-01-01

    Emergence of different ctxB genotypes within virulent Vibrio cholerae populations accentuates the need to develop a vaccine that has the potential to protect against all cholera toxin genotypes. Oral administration of rCTB—alone and in combination with 2 dominant domestic killed whole cells of V. cholerae (O1 Ogawa El Tor and O1 Inaba El Tor) plus one standard V. cholerae (O1 Ogawa classic ATCC 14035)—has shown satisfactory protection as a potent vaccine candidate against toxigenic V. cholerae. PMID:24165439

  15. Changing genotypes of cholera toxin (CT) of Vibrio cholerae O139 in Bangladesh and description of three new CT genotypes.

    Science.gov (United States)

    Bhuiyan, Nurul A; Nusrin, Suraia; Alam, Munirul; Morita, Masatomo; Watanabe, Haruo; Ramamurthy, Thandavarayan; Cravioto, Alejandro; Nair, Gopinath Balakrish

    2009-11-01

    We determined the genotype of cholera toxin by amplifying and sequencing the B-subunit in a sequential collection of 90 strains of Vibrio cholerae O139 isolated over the past 13 years since its first description in 1992. Representative strains isolated during 1993-1997 harboured ctxB of El Tor type (genotype 3). Twenty-six strains isolated during 1999, 2001, 2005 and three strains isolated in 1998, 2000 and 2002 were identified to belong to new ctxB genotypes 4 and 5, respectively. Genotype 5 was similar to genotype 1 except at position 28 (D-->A). The genotype 6 was similar to genotype 4 except at position 34 (H-->P). The implication of switch in terms of function of the toxin and its impact on human disease is unclear. How this change has influenced their prevalence relative to that of V. cholerae O1 in human infection is also not clear. The other common virulence gene clusters including the Vibrio pathogenicity island-1, Vibrio seventh pandemic island (VSP)-I and VSP-II of V. cholerae O139 did not show any remarkable difference from that of the O1 El Tor strains. Overall, the majority of the O139 strains tested in this study were similar to the El Tor strains but had altered ctxB genotype. This change and the impact that it causes to the epidemiology of cholera caused by O139 should be closely monitored.

  16. Conjugated Linoleic Acid Reduces Cholera Toxin Production In Vitro and In Vivo by Inhibiting Vibrio cholerae ToxT Activity.

    Science.gov (United States)

    Withey, Jeffrey H; Nag, Drubhajyoti; Plecha, Sarah C; Sinha, Ritam; Koley, Hemanta

    2015-12-01

    The severe diarrheal disease cholera is endemic in over 50 countries. Current therapies for cholera patients involve oral and/or intravenous rehydration, often combined with the use of antibiotics to shorten the duration and intensity of the disease. However, as antibiotic resistance increases, treatment options will become limited. Linoleic acid has been shown to be a potent negative effector of V. cholerae virulence that acts on the major virulence transcription regulator protein, ToxT, to inhibit virulence gene expression. ToxT activates transcription of the two major virulence factors required for disease, cholera toxin (CT) and toxin-coregulated pilus (TCP). A conjugated form of linoleic acid (CLA) is currently sold over the counter as a dietary supplement and is generally recognized as safe by the U.S. Food and Drug Administration. This study examined whether CLA could be used as a new therapy to reduce CT production, which, in turn, would decrease disease duration and intensity in cholera patients. CLA could be used in place of traditional antibiotics and would be very unlikely to generate resistance, as it affects only virulence factor production and not bacterial growth or survival.

  17. Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

    Directory of Open Access Journals (Sweden)

    Daniel Rios Garza

    Full Text Available The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics.

  18. Conjugated Linoleic Acid Reduces Cholera Toxin Production In Vitro and In Vivo by Inhibiting Vibrio cholerae ToxT Activity

    Science.gov (United States)

    Nag, Drubhajyoti; Plecha, Sarah C.; Sinha, Ritam; Koley, Hemanta

    2015-01-01

    The severe diarrheal disease cholera is endemic in over 50 countries. Current therapies for cholera patients involve oral and/or intravenous rehydration, often combined with the use of antibiotics to shorten the duration and intensity of the disease. However, as antibiotic resistance increases, treatment options will become limited. Linoleic acid has been shown to be a potent negative effector of V. cholerae virulence that acts on the major virulence transcription regulator protein, ToxT, to inhibit virulence gene expression. ToxT activates transcription of the two major virulence factors required for disease, cholera toxin (CT) and toxin-coregulated pilus (TCP). A conjugated form of linoleic acid (CLA) is currently sold over the counter as a dietary supplement and is generally recognized as safe by the U.S. Food and Drug Administration. This study examined whether CLA could be used as a new therapy to reduce CT production, which, in turn, would decrease disease duration and intensity in cholera patients. CLA could be used in place of traditional antibiotics and would be very unlikely to generate resistance, as it affects only virulence factor production and not bacterial growth or survival. PMID:26392502

  19. Stepwise changes in viable but nonculturable Vibrio cholerae cells.

    Science.gov (United States)

    Imamura, Daisuke; Mizuno, Tamaki; Miyoshi, Shin-ichi; Shinoda, Sumio

    2015-05-01

    Many bacterial species are known to become viable but nonculturable (VBNC) under conditions that are unsuitable for growth. In this study, the requirements for resuscitation of VBNC-state Vibrio cholerae cells were found to change over time. Although VBNC cells could initially be converted to culturable by treatment with catalase or HT-29 cell extract, they subsequently entered a state that was not convertible to culturable by these factors. However, fluorescence microscopy revealed the presence of live cells in this state, from which VBNC cells were resuscitated by co-cultivation with HT-29 human colon adenocarcinoma cells. Ultimately, all cells entered a state from which they could not be resuscitated, even by co-cultivation with HT-29. These characteristic changes in VBNC-state cells were a common feature of strains in both V. cholerae O1 and O139 serogroups. Thus, the VBNC state of V. cholerae is not a single property but continues to change over time.

  20. Nitrosative Stress Response in Vibrio cholerae: Role of S-Nitrosoglutathione Reductase.

    Science.gov (United States)

    Patra, Sourav Kumar; Bag, Prasanta Kumar; Ghosh, Sanjay

    2016-12-20

    Vibrio cholerae, the causative agent of cholera, poses serious threats to humans worldwide. V. cholerae faces host inflammatory response and encounters nitrosative stress before establishing successful colonization. It is not clear how V. cholerae combats nitric oxide and reactive nitrogen species. In the present study, we used three clinical strains of V. cholerae and tested their nitrosative stress response pattern towards sodium nitroprusside (SNP) and S-Nitrosoglutathione (GSNO). Among them, V. cholerae, belonging to both O1 and O139 serotypes, showed moderate resistance to SNP and GSNO. However, a V. cholerae strain belonging to non O1 and non O139 showed sensitivity to SNP but resistance towards GSNO. Reduced glutathione and glutathione reductase play a significant role to combat nitrosative stress in V. cholerae. This is the first report where we show the presence of GSNO reductase activity in V. cholerae and that it plays an important role to detoxify S-Nitrosoglutathione. GSNO reductase activity of V. cholerae was regulated by posttranslational modification through S-nitrosylation under in vitro conditions which could be reversed by dithiothreitol (DTT). In addition, we show that biofilm formation remained unaffected under nitrosative stress in V. cholerae.

  1. Influence of climate factors on Vibrio cholerae dynamics in the Pearl River estuary, South China.

    Science.gov (United States)

    Yue, Yujuan; Gong, Jianhua; Wang, Duochun; Kan, Biao; Li, Baisheng; Ke, Changwen

    2014-06-01

    Current research has seldom focused on the quantitative relationships between Vibrio cholerae (V. cholerae) and climate factors owing to the complexities and high cost of field observation in the aquatic environment. This study has focused on the relationships between V. cholerae and climate factors based on linear regression method and data partition method. Data gathered from 2008 to 2009 in the Pearl River estuary, South China, were adopted. Positive rate of V. cholerae was correlated closely with monthly climate factors of water temperature and air temperature, respectively in 2009. Quarterly data analysis from 2008 to 2009 showed that there existed seasonal characteristic for V. cholerae. Positive rate of V. cholerae was correlated positively with quarterly climate factors of land surface temperature, pH, water temperature, air temperature and rainfall, respectively and negatively with quarterly air pressure. Partition data analysis in 2009 showed that there existed geography region characteristic for V. cholerae. V. cholerae dynamics was closely correlated to climate factors in the downstream area. However, it was more greatly affected by human geography factors in the urban area. Positive annual rate of V. cholerae was higher in the downstream area than in the urban area both in 2008 and 2009. At last, a cellular automaton model was used to simulate V. cholerae diffusion downstream, and the distribution of V. cholerae obtained from this model was similar to that obtained from the field observations.

  2. A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

    Science.gov (United States)

    Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control.

  3. Cholera and household water treatment why communities do not treat water after a cholera outbreak: a case study in Limpopo Province

    OpenAIRE

    Mudau, Lutendo Sylvia; Mukhola, Murembiwa Stanley; Hunter, Paul Raymond

    2016-01-01

    Background: Cholera is one of the common diseases in developing countries caused by consumption of contaminated and untreated drinking water. A study was conducted 7 months after a cholera outbreak in Vhembe district, Limpopo, South Africa. The aim of the study was to assess if the communities were still conforming to safe water practices after an outbreak of cholera. Methodology: One hundred and fifty-two (152) participants from 11 villages were recruited to form 21 focus groups, with a mean...

  4. Priming immunization against cholera toxin and E. coli heat-labile toxin by a cholera toxin short peptide-beta-galactosidase hybrid synthesized in E. coli.

    OpenAIRE

    Jacob, C O; Leitner, M.; Zamir, A.; Salomon, D.; Arnon, R

    1985-01-01

    A synthetic oligodeoxynucleotide encoding for a small peptide was employed for the expression of this peptide in a form suitable for immunization. The encoded peptide, namely, the region 50-64 of the B subunit of cholera toxin (CTP3), had previously been identified as a relevant epitope of cholera toxin. Thus, multiple immunizations with its conjugate to a protein carrier led to an efficient neutralizing response against native cholera toxin. Immunization with the resulting fusion protein of ...

  5. Spatial and environmental connectivity analysis in a cholera vaccine trial.

    Science.gov (United States)

    Emch, Michael; Ali, Mohammad; Root, Elisabeth D; Yunus, Mohammad

    2009-02-01

    This paper develops theory and methods for vaccine trials that utilize spatial and environmental information. Satellite imagery is used to identify whether households are connected to one another via water bodies in a study area in rural Bangladesh. Then relationships between neighborhood-level cholera vaccine coverage and placebo incidence and neighborhood-level spatial variables are measured. The study hypothesis is that unvaccinated people who are environmentally connected to people who have been vaccinated will be at lower risk compared to unvaccinated people who are environmentally connected to people who have not been vaccinated. We use four datasets including: a cholera vaccine trial database, a longitudinal demographic database of the rural population from which the vaccine trial participants were selected, a household-level geographic information system (GIS) database of the same study area, and high resolution Quickbird satellite imagery. An environmental connectivity metric was constructed by integrating the satellite imagery with the vaccine and demographic databases linked with GIS. The results show that there is a relationship between neighborhood rates of cholera vaccination and placebo incidence. Thus, people are indirectly protected when more people in their environmentally connected neighborhood are vaccinated. This result is similar to our previous work that used a simpler Euclidean distance neighborhood to measure neighborhood vaccine coverage [Ali, M., Emch, M., von Seidlein, L., Yunus, M., Sack, D. A., Holmgren, J., et al. (2005). Herd immunity conferred by killed oral cholera vaccines in Bangladesh. Lancet, 366(9479), 44-49]. Our new method of measuring environmental connectivity is more precise since it takes into account the transmission mode of cholera and therefore this study validates our assertion that the oral cholera vaccine provides indirect protection in addition to direct protection.

  6. Whole-genome sequence comparisons reveal the evolution of Vibrio cholerae O1.

    Science.gov (United States)

    Kim, Eun Jin; Lee, Chan Hee; Nair, G Balakrish; Kim, Dong Wook

    2015-08-01

    The analysis of the whole-genome sequences of Vibrio cholerae strains from previous and current cholera pandemics has demonstrated that genomic changes and alterations in phage CTX (particularly in the gene encoding the B subunit of cholera toxin) were major features in the evolution of V. cholerae. Recent studies have revealed the genetic mechanisms in these bacteria by which new variants of V. cholerae are generated from type-specific strains; these mechanisms suggest that certain strains are selected by environmental or human factors over time. By understanding the mechanisms and driving forces of historical and current changes in the V. cholerae population, it would be possible to predict the direction of such changes and the evolution of new variants; this has implications for the battle against cholera.

  7. Environmental surveillance for toxigenic Vibrio cholerae in surface waters of Haiti.

    Science.gov (United States)

    Kahler, Amy M; Haley, Bradd J; Chen, Arlene; Mull, Bonnie J; Tarr, Cheryl L; Turnsek, Maryann; Katz, Lee S; Humphrys, Michael S; Derado, Gordana; Freeman, Nicole; Boncy, Jacques; Colwell, Rita R; Huq, Anwar; Hill, Vincent R

    2015-01-01

    Epidemic cholera was reported in Haiti in 2010, with no information available on the occurrence or geographic distribution of toxigenic Vibrio cholerae in Haitian waters. In a series of field visits conducted in Haiti between 2011 and 2013, water and plankton samples were collected at 19 sites. Vibrio cholerae was detected using culture, polymerase chain reaction, and direct viable count methods (DFA-DVC). Cholera toxin genes were detected by polymerase chain reaction in broth enrichments of samples collected in all visits except March 2012. Toxigenic V. cholerae was isolated from river water in 2011 and 2013. Whole genome sequencing revealed that these isolates were a match to the outbreak strain. The DFA-DVC tests were positive for V. cholerae O1 in plankton samples collected from multiple sites. Results of this survey show that toxigenic V. cholerae could be recovered from surface waters in Haiti more than 2 years after the onset of the epidemic.

  8. An intracellular replication niche for Vibrio cholerae in the amoeba Acanthamoeba castellanii.

    Science.gov (United States)

    Van der Henst, Charles; Scrignari, Tiziana; Maclachlan, Catherine; Blokesch, Melanie

    2016-04-01

    Vibrio cholerae is a human pathogen and the causative agent of cholera. The persistence of this bacterium in aquatic environments is a key epidemiological concern, as cholera is transmitted through contaminated water. Predatory protists, such as amoebae, are major regulators of bacterial populations in such environments. Therefore, we investigated the interaction between V. cholerae and the amoeba Acanthamoeba castellanii at the single-cell level. We observed that V. cholerae can resist intracellular killing. The non-digested bacteria were either released or, alternatively, established a replication niche within the contractile vacuole of A. castellanii. V. cholerae was maintained within this compartment even upon encystment. The pathogen ultimately returned to its aquatic habitat through lysis of A. castellanii, a process that was dependent on the production of extracellular polysaccharide by the pathogen. This study reinforces the concept that V. cholerae is a facultative intracellular bacterium and describes a new host-pathogen interaction.

  9. A cocktail of three virulent bacteriophages prevents Vibrio cholerae infection in animal models

    Science.gov (United States)

    Yen, Minmin; Cairns, Lynne S.; Camilli, Andrew

    2017-01-01

    Effective prevention strategies will be essential in reducing disease burden due to bacterial infections. Here we harness the specificity and rapid-acting properties of bacteriophages as a potential prophylaxis therapy for cholera, a severely dehydrating disease caused by Vibrio cholerae. To this end, we test a cocktail of three virulent phages in two animal models of cholera pathogenesis (infant mouse and rabbit models). Oral administration of the phages up to 24 h before V. cholerae challenge reduces colonization of the intestinal tract and prevents cholera-like diarrhea. None of the surviving V. cholerae colonies are resistant to all three phages. Genome sequencing and variant analysis of the surviving colonies indicate that resistance to the phages is largely conferred by mutations in genes required for the production of the phage receptors. For acute infections, such as cholera, phage prophylaxis could provide a strategy to limit the impact of bacterial disease on human health. PMID:28146150

  10. Clinical manifestations of non-O1 Vibrio cholerae infections.

    Directory of Open Access Journals (Sweden)

    Yen-Ting Chen

    Full Text Available BACKGROUND: Infections caused by non-O1 Vibrio cholera are uncommon. The aim of our study was to investigate the clinical and microbiological characteristics of patients with non-O1 V. cholera infections. METHODS: The clinical charts of all patients with non-O1 V. cholera infections and who were treated in two hospitals in Taiwan were retrospectively reviewed. RESULTS: From July 2009 to June 2014, a total of 83 patients with non-O1 V. cholera infections were identified based on the databank of the bacteriology laboratories of two hospitals. The overall mean age was 53.3 years, and men comprised 53 (63.9% of the patients. Liver cirrhosis and diabetes mellitus were the two most common underlying diseases, followed by malignancy. The most common type of infection was acute gastroenteritis (n = 45, 54.2%, followed by biliary tract infection (n = 12, 14.5% and primary bacteremia (n = 11, 13.3%. Other types of infection, such as peritonitis (n = 5, 6.0%, skin and soft tissue infection (SSTI (n = 5, 6.0%, urinary tract infection (n = 3, 3.6% and pneumonia (2, 2.4%, were rare. July and June were the most common months of occurrence of V. cholera infections. The overall in-hospital mortality of 83 patients with V. cholera infections was 7.2%, but it was significantly higher for patients with primary bacteremia, hemorrhage bullae, acute kidney injury, acute respiratory failure, or admission to an ICU. Furthermore, multivariate analysis showed that in-hospital mortality was significantly associated with acute respiratory failure (odds ratio, 60.47; 95% CI, 4.79-763.90, P = 0.002. CONCLUSIONS: Non-O1 V. cholera infections can cause protean disease, especially in patients with risk factors and during warm-weather months. The overall mortality of 83 patients with non-O1 V. cholera infections was only 7.2%; however, this value varied among different types of infection.

  11. Cholera at the crossroads: the association between endemic cholera and national access to improved water sources and sanitation.

    Science.gov (United States)

    Nygren, Benjamin L; Blackstock, Anna J; Mintz, Eric D

    2014-11-01

    We evaluated World Health Organization (WHO) national water and sanitation coverage levels and the infant mortality rate as predictors of endemic cholera in the 5-year period following water and sanitation coverage estimates using logistic regression, receiver operator characteristic curves, and different definitions of endemicity. Each was a significant predictors of endemic cholera at P sanitation access level of 39% has 63% sensitivity and 62% specificity, and an infant mortality rate of 65/1,000 has 67% sensitivity and 69% specificity. Our findings reveal the tradeoff between sensitivity and specificity for these predictors of endemic cholera and highlight the substantial uncertainty in the data. More accurate global surveillance data will enable more precise characterization of the benefits of improved water and sanitation.

  12. Identification of the secreted component(s) of V.cholerae that induces an intestinal epithelial inflammatory response%霍乱弧菌致病因子诱导人肠上皮细胞炎症反应的实验研究

    Institute of Scientific and Technical Information of China (English)

    欧刚卫

    2009-01-01

    目的: 鉴定诱导人肠上皮细胞炎性反应的霍乱弧菌分泌产物.方法: 野生型霍乱弧菌O1株C6706及其变异株培养上清刺激极化的人单层肠上皮T84细胞体外模型上层腔面,分析细胞受刺激后通透性和细胞活性以及白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)基因表达改变;分析上清中霍乱弧菌蛋白酶(Vibrio cholerae protease,PrtV)和霍乱弧菌溶细胞素(Vibrio cholera cytolysin,VCC)含量以及溶血能力.结果: PrtV缺失株培养上清可引起T84细胞层的炎性反应,表现为通透性增加和IL-8,TNF-α基因表达增加.肠上皮细胞炎性反应及红细胞溶血反应与VCC活性有关.结论: VCC是霍乱弧菌引起人肠上皮细胞炎性反应的主要因素,PrtV通过降解VCC而降低对肠上皮细胞的炎性反应.

  13. Vibrio cholerae VttRA and VttRB Regulatory Influences Extend beyond the Type 3 Secretion System Genomic Island

    OpenAIRE

    Chaand, Mudit; Dziejman, Michelle

    2013-01-01

    A subset of non-O1/non-O139 serogroup strains of Vibrio cholerae cause disease using type 3 secretion system (T3SS)-mediated mechanisms. An ∼50-kb genomic island carries genes encoding the T3SS structural apparatus, effector proteins, and two transmembrane transcriptional regulators, VttRA and VttRB, which are ToxR homologues. Previous experiments demonstrated that VttRA and VttRB are necessary for colonization in vivo and promote bile-dependent T3SS gene expression in vitro. To better unders...

  14. Growth of Vibrio cholerae O1 Ogawa Eltor in freshwater.

    Science.gov (United States)

    Vital, Marius; Füchslin, Hans Peter; Hammes, Frederik; Egli, Thomas

    2007-07-01

    Growth of Vibrio cholerae O1 Ogawa Eltor was studied with a growth assay in which autoclaved and filtered (0.22 microm) freshwater was inoculated at low cell density (5 x 10(3) cells ml(-1)) and proliferation was followed with flow cytometry. Against the common view, V. cholerae was able to grow extensively in different kinds of freshwater. The bacterium multiplied in river water, lake water and effluent of a wastewater treatment plant up to a cell density of 1.55 x 10(6) cells ml(-1). In these samples, apparent assimilable organic carbon (AOC(app)) concentrations ranged from 52 up to 800 microg l(-1) and the results demonstrate a positive trend between the AOC(app) concentration and final cell concentration, suggesting that AOC was a key parameter governing growth of V. cholerae. No growth was observed in waters (tap and bottled drinking water) containing less than approximately 60 microg AOC(app) l(-1). When pure cultures of V. cholerae were grown on identical lake water at different temperatures (20, 25 and 30 degrees C) the maximum specific growth rates (micromax) achieved were 0.22 h(-1), 0.32 h(-1) and 0.45 h(-1), respectively. In addition, growth was characterized in lake water samples amended with different concentrations of NaCl. The highest micromax of V. cholerae was recorded at moderate salinity levels (5 g NaCl l(-1), micromax=0.84 h(-1)), whereas at 30 g NaCl l(-1) (micromax=0.30 h(-1)) or 0 g NaCl l(-1) (micromax)=0.40 h(-1)) specific growth rates were significantly reduced. In the water tested here, micro(max) of V. cholerae was always around 50 % of that exhibited by a freshwater community of indigenous bacteria enriched from the water sampling site. Direct batch competition experiments between V. cholerae and the lake water bacterial community were performed at different temperatures in which V. cholerae was enumerated in the total community using fluorescent-surface antibodies. In all cases V. cholerae was able to grow and constituted around 10

  15. A recent outbreak of cholera due to Vibrio cholerae O1 Ogawa in & around Chandigarh, North India.

    Science.gov (United States)

    Taneja, Neelam; Kaur, Jasjit; Sharma, Kusum; Singh, Malkit; Kalra, J K; Sharma, N M; Sharma, Meera

    2003-06-01

    An outbreak of cholera caused by Vibrio cholerae O1 Ogawa occurred in and around Chandigarh during July 22-31, 2002. Of the 303 patients admitted to two hospitals, 82 were confirmed by culture. Two rehabilitation colonies located at the periphery of Chandigarh were mainly affected. The isolates were biotyped as Eltor and were susceptible to many antibiotics. Thirty one (35.2%) of 88 water samples showed evidence of faecal contamination. The survey of the area revealed sewage contamination of the drinking water supply. The outbreak was controlled by providing safe drinking water to the people and correcting the defects in the sewage and water pipelines.

  16. Comparison of two recombinant systems for expression of cholera toxin B subunit from Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    M Boustanshenas

    2013-01-01

    Full Text Available Purpose: The aim of this study was to assess the production of recombinant cholera toxin B subunit (rCTB protein in two different expression systems (pAE_ctxB and pQE_ctxB constructs in Escherichia coli BL21 (DE3. Materials and Methods: The ctxB fragment was amplified from Vibrio cholerae O 1 ATCC14035 and cloned in pGETM-T easy vector after which it was transformed to E. coli Top 10F′ and grown on LB-ampicillin agar medium. Sequence analysis confirmed the complete ctxB gene sequence in the construct which was further subcloned to pQE-30 vector. The construct was subsequently transformed to E. coli M15 (pREP4. The recombinant pAE_ctxB and pQE_ctxB were transformed to competent E. coli BL21 (DE3 cells to express CTB protein. Result: Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE analysis showed the maximum expression of rCTB in both systems at 5 h after induction and western blot analysis confirmed the presence of recombinant CTB in blotting membranes. Conclusion: Expression of rCTB in pAE_ctxB construct was more efficient (15-fold than pQE_ctxB, and it seems that Lac UV5 in E. coli BL21 (DE3 is more compatible with the former construct. This expression system can be used to produce recombinant CTB in high yield which may enable us to study the oral tolerance or mucosal adjuvant properties of rCTB using animal models.

  17. Host-pathogen interactions: A cholera surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Aaron T.

    2016-02-22

    Bacterial pathogen-secreted proteases may play a key role in inhibiting a potentially widespread host-pathogen interaction. Activity-based protein profiling enabled the identification of a major Vibrio cholerae serine protease that limits the ability of a host-derived intestinal lectin to bind to the bacterial pathogen in vivo.

  18. Biofilm recruitment of Vibrio cholerae by matrix proteolysis.

    Science.gov (United States)

    Duperthuy, Marylise; Uhlin, Bernt Eric; Wai, Sun Nyunt

    2015-11-01

    The appearance of bacterial biofilms involves secretion of polysaccharides and proteins that form an extracellular matrix embedding the bacteria. Proteases have also been observed, but their role has remained unclear. Smith and co-workers have now found that proteolysis can contribute to further recruitment of bacteria to Vibrio cholerae biofilms.

  19. [The in vitro action of plants on Vibrio cholerae].

    Science.gov (United States)

    Guevara, J M; Chumpitaz, J; Valencia, E

    1994-01-01

    Natural products of several plants, according to the geographic location, are used by Peruvian people in the popular treatment of diarrhea, with good success. When cholerae cases appeared in Peru, we were interested to know the "in vitro" effect against Vibrio cholerae 01, of these useful plants to treat diarrhea. The following plants were tested: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Punica granatum, Malus sativa, Cydonia oblonga, Chenopodium ambrosoides, Krameria triandria, Tea chinensis, Daucus carota, Persea gratissima, Psidium guayaba and Lippia dulcis. Decoction or infusion of the plants were used in the "in vitro" experiments. The following plants showed no "in vitro" effect against V. cholerae: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Chenopodium ambrosoides, Krameria triandria, Psidium guayaba, Lippia dulcis and Daucus carota. Decoction of Malus sativa and Cydenia oblonga showed bactericidal effect for their acidity and stone avocado (Persea gratissima) a late bactericidal effect. Tea infusión and the decoction of Punica granatum peel, showed the best bactericidal effect and we suggest to use them as to stop cholera spreading.

  20. Experimental study on administration of microeneapsulated vibrio cholera vaccine.

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Objective: To study the effect of biodegradable microspheres as a vaccine delivery system for V. cholera antigen. Methods: The outer membrane protein (OMP, 41KDa) was obtained from the strain Enaba 569B, and the OMP was encapsulated in the biodegrad-

  1. Fucosylation and protein glycosylation create functional receptors for cholera toxin

    DEFF Research Database (Denmark)

    Wands, Amberlyn M; Fujita, Akiko; McCombs, Janet E

    2015-01-01

    Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we...

  2. 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.

  3. Functional characterization of cholera toxin inhibitors using human intestinal organoids

    NARCIS (Netherlands)

    Zomer-van Ommen, Domenique D.; Pukin, Aliaksei V.; Fu, Ou; Quarles Van Ufford, Linda H C; Janssens, Hettie M.; Beekman, Jeffrey M.; Pieters, Roland J.

    2016-01-01

    Preclinical drug testing in primary human cell models that recapitulate disease can significantly reduce animal experimentation and time-to-the-clinic. We used intestinal organoids to quantitatively study the potency of multivalent cholera toxin inhibitors. The method enabled the determination of IC

  4. Low detection of Vibrio cholerae carriage in healthcare workers returning to 12 Latin American countries from Haiti.

    Science.gov (United States)

    Llanes, R; Somarriba, L; Hernández, G; Bardaji, Y; Aguila, A; Mazumder, R N

    2015-04-01

    SUMMARY This investigation was undertaken to characterize the prevalence of intestinal Vibrio cholerae in healthcare workers (HCWs) returning from Haiti due to the ongoing cholera epidemic. Eight hundred and fifty asymptomatic HCWs of the Cuban Medical Brigade, who planned to leave Haiti, were studied by laboratory screening of stool culture for V. cholerae. A very low percentage (0.23%) of toxigenic V. cholerae serogroup O1, serotype Ogawa was found. To the best of our knowledge, this study represents the largest reported screening study for V. cholerae infection in asymptomatic HCWs returning from a cholera-affected country. Cholera transmission to health personnel highlights a possible risk of transmitting cholera during mobilization of the population for emergency response. Aid workers are encouraged to take precautions to reduce their risk for acquiring cholera and special care should be taken by consuming safe water and food and practising regular hand washing.

  5. Acanthamoeba polyphaga is a possible host for Vibrio cholerae in aquatic environments.

    Science.gov (United States)

    Sandström, Gunnar; Saeed, Amir; Abd, Hadi

    2010-09-01

    Acanthamoeba is a genus of free-living amoebae found to be able to host many bacterial species living in the environment. Acanthamoebae and Vibrio cholerae are found in the aquatic environments of cholera endemic areas. Previously it has been shown that V. cholerae O1 and O139 can survive and grow in Acanthamoeba castellanii. The aim of this study was to examine the ability of Acanthamoeba polyphaga to host V. cholerae O1 and O139. The interaction between A. polyphaga and V. cholerae strains was studied by means of viable amoeba cell counts and viable count of the bacteria in the absence and presence of amoebae. The viable count of intracellularly growing bacteria was estimated by utilizing gentamicin assay. Electron microscopy was used to determine the localization of V. cholerae inside A. polyphaga. The results showed that A. polyphaga enhanced growth and survival of V. cholerae, which grew and survived inside the amoeba cells for 2weeks. The electron microscopy showed that A. polyphaga hosted intracellular V. cholerae localized in the vacuoles of amoeba cell. Neither the presence of V. cholerae together with A. polyphaga nor the intracellular localization of the bacteria inhibited growth and survival of A. polyphaga. The outcome of the interaction between these microorganisms may support strongly the role of A. polyphaga as host for V. cholerae O1 and O139.

  6. The epidemiology and antimicrobial resistance of cholera cases in Iran during 2013

    Directory of Open Access Journals (Sweden)

    Hossein Masoumi Asl

    2016-12-01

    Full Text Available Background and Objectives: Cholera is an endemic diarrheal disease in Iran, caused by Vibrio Cholerae. The epidemiology, transmission route, environmental determinants and antimicrobial resistant pattern of cholera have been changed during recent years. In this study the epidemiology and antimicrobial resistance of cholera in Iran during 2013 outbreak was investigated.Materials and Methods: A retrospective, cross-sectional study was carried out using cholera national surveillance system collected data in 2013. Bacterial identification and antimicrobial susceptibility testing were done on 60 Vibrio cholerae isolates, serotype Inaba.Results: During July to November 2013, 256 confirmed cholera cases were diagnosed by stool culture. Two hundred and eleven out of 256 (83% cases were imported from Afghanistan and Pakistan. The prevalent age group was 16-30 years old, 90% were male, 98.8% affected by Inaba serotype and case fatality rate was 2.7%. The results of antimicrobial susceptibility testing on 60 V. cholerae, serotype Inaba showed that all isolates were resistant to nalidixic acid, tetracyclin and trimethoprim- sulfamethoxazole and intermediate resistance to erythromycin but sensitive to ciprofloxacin, cefixime and ampicillin.Conclusion: Migrants from neighboring countries played a key role in cholera outbreak in Iran during 2013. The results of antimicrobial susceptibility testing on 60 V. cholerae, serotype Inaba showed an increasing resistance rate in comparison with previous years. 

  7. Cholera outbreaks in South and Southeast Asia: descriptive analysis, 2003-2012.

    Science.gov (United States)

    Mahapatra, Tanmay; Mahapatra, Sanchita; Babu, Giridhara R; Tang, Weiming; Banerjee, Barnali; Mahapatra, Umakanta; Das, Aritra

    2014-01-01

    We conducted descriptive analysis of available information regarding the epidemiology of cholera outbreaks in South and Southeast Asia during 2003-2012. Information from 58 articles, 8 reports, and World Health Organization databases were analyzed. Overall, 113 cholera outbreaks were studied in South and Southeast Asia during the past 10 years. The majority of the outbreaks (69%) occurred in Southeast Asia, including India (52%). The highest number of outbreaks was observed in 2004 (25.7%). The most commonly identified source was contaminated water: however, in some countries, the spread of cholera was facilitated via contaminated seafood (e.g., Myanmar, Thailand, and Singapore). Several genotypes and phenotypes of Vibrio cholerae, the causative agent of cholera, were identified in the outbreaks, including V. cholerae O1 El Tor (Ogawa and Inaba) and V. cholerae O139. The emergence of multidrug-resistant V. cholerae strains was a major concern. Cholera-related mortality was found to be low across the outbreaks, except in Orissa, India (currently Odisha) during 2007, where the case fatality rate was 8.6%. Potential limitations included underreporting, discrepancies, possible exclusion of nonindexed reports, and incomprehensive search terms. The provision of safe water and proper sanitation appear to be critical for the control of further spread of cholera in South Asian and Southeast Asian regions.

  8. Insights into Vibrio cholerae intestinal colonization from monitoring fluorescently labeled bacteria.

    Science.gov (United States)

    Millet, Yves A; Alvarez, David; Ringgaard, Simon; von Andrian, Ulrich H; Davis, Brigid M; Waldor, Matthew K

    2014-10-01

    Vibrio cholerae, the agent of cholera, is a motile non-invasive pathogen that colonizes the small intestine (SI). Most of our knowledge of the processes required for V. cholerae intestinal colonization is derived from enumeration of wt and mutant V. cholerae recovered from orogastrically infected infant mice. There is limited knowledge of the distribution of V. cholerae within the SI, particularly its localization along the villous axis, or of the bacterial and host factors that account for this distribution. Here, using confocal and intravital two-photon microscopy to monitor the localization of fluorescently tagged V. cholerae strains, we uncovered unexpected and previously unrecognized features of V. cholerae intestinal colonization. Direct visualization of the pathogen within the intestine revealed that the majority of V. cholerae microcolonies attached to the intestinal epithelium arise from single cells, and that there are notable regiospecific aspects to V. cholerae localization and factors required for colonization. In the proximal SI, V. cholerae reside exclusively within the developing intestinal crypts, but they are not restricted to the crypts in the more distal SI. Unexpectedly, V. cholerae motility proved to be a regiospecific colonization factor that is critical for colonization of the proximal, but not the distal, SI. Furthermore, neither motility nor chemotaxis were required for proper V. cholerae distribution along the villous axis or in crypts, suggesting that yet undefined processes enable the pathogen to find its niches outside the intestinal lumen. Finally, our observations suggest that host mucins are a key factor limiting V. cholerae intestinal colonization, particularly in the proximal SI where there appears to be a more abundant mucus layer. Collectively, our findings demonstrate the potent capacity of direct pathogen visualization during infection to deepen our understanding of host pathogen interactions.

  9. Hydrology and Human Health: Predicting Cholera Outbreaks using Remote Sensing Data

    Science.gov (United States)

    Jutla, A. S.; Akanda, A. S.; Islam, S.

    2010-12-01

    Cholera bacteria survive and thrive in two distinctively different environments: the micro- and the macro-environmental processes that vary over a range of spatial and temporal scales. While micro-environmental conditions are necessary for maintaining epidemic conditions, macro-environmental conditions set the stage for initial outbreak and endemicity of the disease. As macro-environmental processes provide natural ecological niche for V. cholerae and there is powerful evidence of new biotypes emerging, it is unlikely that cholera will be fully eradicated, a condition which necessitates exploration of alternate means to develop prediction mechanism for cholera outbreaks. Satellite remote sensing data provides reliable estimates of plankton abundance through chlorophyll content which then can be used to understand cholera - chlorophyll relationships. However, the functional nature of association of cholera incidence with chlorophyll and its predictive capabilities are not well understood. Here we show that cholera outbreaks in Bengal Delta can be predicted two to three months in advance with an overall prediction accuracy of greater than 80% using combination of satellite derived chlorophyll and air temperature. Such high prediction accuracy is achievable because the two seasonal peaks of cholera in Bengal Delta are controlled by two distinctive macro-environmental processes. We have found that interannual variability of pre- monsoonal cholera outbreaks is intricately linked with coastal plankton through a cascade of hydro-coastal processes. Post- monsoonal cholera outbreaks, on the other hand, are related with wide spreading flooding and subsequent breakdown of the sanitary conditions. Our results demonstrate that satellite data, with a careful choice of space and time scales, can be very effective to develop a cholera prediction model for the Bengal delta with several months lead time. We anticipate that our modeling framework will provide essential lead time for

  10. Connecting Environmental Observations with Cholera Outbreaks in Bangladesh

    Science.gov (United States)

    Stack, D.; Sandborn, A.; Widmeyer, P. A.; Escobar, V. M.

    2011-12-01

    Research has demonstrated that cholera epidemics in Bangladesh occur seasonally. This bimodal outbreak pattern closely follows times when large monsoon events are most frequent (spring and fall). While these patterns are presented in regional data, this knowledge alone cannot forecast the severity and location of cholera outbreaks until a monsoon event occurs, or an outbreak is reported. Therefore, there can only be reactive responses to cholera outbreaks. A heightened understanding of the link between environmental factors and outbreak occurrence will greatly enhance disease management capabilities. A predictive tool capable of giving an advanced warning of the environmental hazards that lead to location specific outbreaks allows for proactive and preventative responses, minimizing negative effects. A specific goal of this research was to relate latitude-longitude data with existing points associated with V. cholerae human case data collected from four cities in Bangladesh. Remotely sensed products were used to better understand the correlation between human outbreak occurrences, chlorophyll-a estimates, sea surface temperature (SST), and rainfall. Using MODIS, SeaWiFS, and TRMM satellite data, a gridded regional image was developed. Correlation analyses of the data were studied within the context of geographically diverse locations for the four cities of interest. Seasonal relationships were found between the cholera case data and all three of the chosen remotely sensed parameters. The strongest correlation found was between chlorophyll-a concentrations and reported human cases. The primary deliverable of this project was the production of an interactive Google Earth base map for use in a pilot design study that will lead to the development of applications to connect earth science products with water and health studies. The base map, with its inherent value of merging remotely sensed data with in situ observation points, can be used as a basis for constructing

  11. Antimicrobial Susceptibility of Autochthonous Aquatic Vibrio cholerae in Haiti

    Science.gov (United States)

    Baron, Sandrine; Lesne, Jean; Jouy, Eric; Larvor, Emeline; Kempf, Isabelle; Boncy, Jacques; Rebaudet, Stanilas; Piarroux, Renaud

    2016-01-01

    We investigated the antimicrobial susceptibility of 50 environmental isolates of Vibrio cholerae non-O1/non-O139 collected in surface waters in Haiti in July 2012, during an active cholera outbreak. A panel of 16 antibiotics was tested on the isolates using the disk diffusion method and PCR detection of seven resistance-associated genes (strA/B, sul1/2, ermA/B, and mefA). All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, ciprofloxacin, norfloxacin, amikacin, and gentamicin. Nearly a quarter (22.0%) of the isolates were susceptible to all 16 antimicrobials tested and only 8.0% of the isolates (n = 4) were multidrug-resistant. The highest proportions of resistant isolates were observed for sulfonamide (70.0%), amoxicillin (12.0%), and trimethoprim-sulfamethoxazole (10.0%). One strain was resistant to erythromycin and one to doxycycline, two antibiotics used to treat cholera in Haiti. Among the 50 isolates, 78% possessed at least two resistance-associated genes, and the genes sul1, ermA, and strB were detected in all four multidrug-resistant isolates. Our results clearly indicate that the autochthonous population of V. cholerae non-O1/non-O139 found in surface waters in Haiti shows antimicrobial patterns different from that of the outbreak strain. The presence in the Haitian aquatic environment of V. cholerae non-O1/non-O139 with reduced susceptibility or resistance to antibiotics used in human medicine may constitute a mild public health threat. PMID:27818656

  12. Fighting Cholera One-on-One: The Development and Efficacy of Multivalent Cholera-Toxin-Binding Molecules

    NARCIS (Netherlands)

    Zuilhof, H.

    2016-01-01

    A series of diseases, ranging from cholera via travelers’ diarrhea to hamburger disease, are caused by bacterially produced toxic proteins. In particular, a toxic protein unit is brought into the host cell upon binding to specific membrane-bound oligosaccharides on the host cell membrane. For exampl

  13. Epidemic cholera in rural El Salvador: risk factors in a region covered by a cholera prevention campaign.

    Science.gov (United States)

    Quick, R E; Thompson, B L; Zuniga, A; Dominguez, G; De Brizuela, E L; De Palma, O; Almeida, S; Valencia, A; Ries, A A; Bean, N H

    1995-04-01

    In response to the Latin American cholera epidemic, El Salvador began a prevention programme in April 1991. The first case was confirmed in August, and 700 cases were reported within 3 months. A matched case-control study was conducted in rural La Libertad Department in November 1991. Illness was associated with eating cold cooked or raw seafood (odds ratio [OR] = 7.0; 95% confidence limits [CL] = 1.4, 35.0) and with drinking water outside the home (OR = 8.8; 95% CL = 1.7, 44.6). Assertion of knowledge about how to prevent cholera (OR = 0.2; 95% CL = 0.1, 0.8) and eating rice (OR = 0.2; 95% CL = 0.1, 0.8) were protective. More controls than patients regularly used soap (OR = 0.3; 95% CL = 0.1, 1.0). This study demonstrated three important points for cholera prevention: (1) seafood should be eaten cooked and hot; (2) populations at risk should be taught to treat household drinking water and to avoid drinking water outside the home unless it is known to be treated; and (3) education about hygiene can be an important tool in preventing cholera.

  14. Competence-induced type VI secretion might foster intestinal colonization by Vibrio cholerae: Intestinal interbacterial killing by competence-induced V. cholerae.

    Science.gov (United States)

    Blokesch, Melanie

    2015-11-01

    The human pathogen Vibrio cholerae exhibits two distinct lifestyles: one in the aquatic environment where it often associates with chitinous surfaces and the other as the causative agent of the disease cholera. While much of the research on V. cholerae has focused on the host-pathogen interaction, knowledge about the environmental lifestyle of the pathogen remains limited. We recently showed that the polymer chitin, which is extremely abundant in aquatic environments, induces natural competence as a mode of horizontal gene transfer and that this competence regulon also includes the type VI secretion system (T6SS), a molecular killing device. Here, I discuss the putative consequences that chitin-induced T6SS activation could have on intestinal colonization and how the transmission route might influence disease outcome. Moreover, I propose that common infant animal models for cholera might not sufficiently take into account T6SS-mediated interbacterial warfare between V. cholerae and the intestinal microbiota.

  15. Adapting to the global shortage of cholera vaccines: targeted single dose cholera vaccine in response to an outbreak in South Sudan.

    Science.gov (United States)

    Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Ciglenecki, Iza; Luquero, Francisco J; Azman, Andrew S; Cabrol, Jean-Clement

    2017-01-18

    Shortages of vaccines for epidemic diseases, such as cholera, meningitis, and yellow fever, have become common over the past decade, hampering efforts to control outbreaks through mass reactive vaccination campaigns. Additionally, various epidemiological, political, and logistical challenges, which are poorly documented in the literature, often lead to delays in reactive campaigns, ultimately reducing the effect of vaccination. In June 2015, a cholera outbreak occurred in Juba, South Sudan, and because of the global shortage of oral cholera vaccine, authorities were unable to secure sufficient doses to vaccinate the entire at-risk population-approximately 1 million people. In this Personal View, we document the first public health use of a reduced, single-dose regimen of oral cholera vaccine, and show the details of the decision-making process and timeline. We also make recommendations to help improve reactive vaccination campaigns against cholera, and discuss the importance of new and flexible context-specific dose regimens and vaccination strategies.

  16. Genomic epidemiology of Vibrio cholerae O1 associated with floods, Pakistan, 2010.

    Science.gov (United States)

    Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib; Wren, Brendan W

    2014-01-01

    In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks.

  17. The Vibrio cholerae type VI secretion system employs diverse effector modules for intraspecific competition.

    Science.gov (United States)

    Unterweger, Daniel; Miyata, Sarah T; Bachmann, Verena; Brooks, Teresa M; Mullins, Travis; Kostiuk, Benjamin; Provenzano, Daniele; Pukatzki, Stefan

    2014-04-01

    Vibrio cholerae is a Gram-negative bacterial pathogen that consists of over 200 serogroups with differing pathogenic potential. Only strains that express the virulence factors cholera toxin (CT) and toxin-coregulated pilus (TCP) are capable of pandemic spread of cholera diarrhoea. Regardless, all V. cholerae strains sequenced to date harbour genes for the type VI secretion system (T6SS) that translocates effectors into neighbouring eukaryotic and prokaryotic cells. Here we report that the effectors encoded within these conserved gene clusters differ widely among V. cholerae strains, and that immunity proteins encoded immediately downstream from the effector genes protect their host from neighbouring bacteria producing corresponding effectors. As a consequence, strains with matching effector-immunity gene sets can coexist, while strains with different sets compete against each other. Thus, the V. cholerae T6SS contributes to the competitive behaviour of this species.

  18. Peru-15, an improved live attenuated oral vaccine candidate for Vibrio cholerae O1.

    Science.gov (United States)

    Kenner, J R; Coster, T S; Taylor, D N; Trofa, A F; Barrera-Oro, M; Hyman, T; Adams, J M; Beattie, D T; Killeen, K P; Spriggs, D R

    1995-10-01

    Cholera vaccine candidate Peru-15 was derived from a Vibrio cholerae O1 El Tor Inaba strain by deleting the cholera toxin genetic element, introducing the gene encoding cholera toxin B subunit into recA, and screening for nonmotility. In a controlled study, Peru-15 (2 x 10(8) cfu) was administered to 11 volunteers. No vaccinee developed diarrhea, and 10 of 11 had > 4-fold rises in vibriocidal antibody titers. One month later, 5 vaccinees and 5 control volunteers were challenged with wild type V. cholerae O1. Four of 5 controls developed diarrhea (mean, 1.9 L). Two Peru-15 vaccinees developed diarrhea, 1 with volunteer had not developed a significant vibriocidal immune response to vaccination. Peru-15 shows promise as a single-dose, oral cholera vaccine that is safe, immunogenic, and protective.

  19. Achievements and challenges for the use of killed oral cholera vaccines in the global stockpile era.

    Science.gov (United States)

    Desai, Sachin N; Pezzoli, Lorenzo; Alberti, Kathryn P; Martin, Stephen; Costa, Alejandro; Perea, William; Legros, Dominique

    2016-11-04

    Cholera remains an important but neglected public health threat, affecting the health of the poorest populations and imposing substantial costs on public health systems. Cholera can be eliminated where access to clean water, sanitation, and satisfactory hygiene practices are sustained, but major improvements in infrastructure continue to be a distant goal. New developments and trends of cholera disease burden, the creation of an affordable cholera vaccine for use in developing countries, as well as recent evidence of vaccination impact has created an increased demand for oral cholera vaccine (OCV). The global OCV stockpile was established in 2013 and with support from Gavi, has assisted in achieving rapid access to vaccine in emergencies. Recent WHO prequalification of a second affordable OCV supports the stockpile goals of increased availability and distribution to affected populations. It serves as an essential step towards an integrated cholera control and prevention strategy in emergency and endemic settings.

  20. Cholera toxin regulates a signaling pathway critical for the expansion of neural stem cell cultures from the fetal and adult rodent brains.

    Directory of Open Access Journals (Sweden)

    Andreas Androutsellis-Theotokis

    Full Text Available BACKGROUND: New mechanisms that regulate neural stem cell (NSC expansion will contribute to improved assay systems and the emerging regenerative approach that targets endogenous stem cells. Expanding knowledge on the control of stem cell self renewal will also lead to new approaches for targeting the stem cell population of cancers. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that Cholera toxin regulates two recently characterized NSC markers, the Tie2 receptor and the transcription factor Hes3, and promotes the expansion of NSCs in culture. Cholera toxin increases immunoreactivity for the Tie2 receptor and rapidly induces the nuclear localization of Hes3. This is followed by powerful cultured NSC expansion and induction of proliferation both in the presence and absence of mitogen. CONCLUSIONS/SIGNIFICANCE: Our data suggest a new cell biological mechanism that regulates the self renewal and differentiation properties of stem cells, providing a new logic to manipulate NSCs in the context of regenerative disease and cancer.

  1. Anti-bacterial and anti-toxic immunity induced by a killed whole-cell-cholera toxin B subunit cholera vaccine is essential for protection against lethal bacterial infection in mouse pulmonary cholera model.

    Science.gov (United States)

    Kang, S-S; Yang, J S; Kim, K W; Yun, C-H; Holmgren, J; Czerkinsky, C; Han, S H

    2013-07-01

    The lack of appropriate animal model for studying protective immunity has limited vaccine development against cholera. Here, we demonstrate a pulmonary cholera model conferred by intranasal administration of mice with live Vibrio cholerae. The bacterial components, but not cholera toxin, caused lethal and acute pneumonia by inducing massive inflammation. Intranasal immunization with Dukoral, comprising killed whole bacteria and recombinant cholera toxin B subunit (rCTB), developed both mucosal and systemic antibody responses with protection against the lethal challenge. Either rCTB-free Dukoral or rCTB alone partially protected the mice against the challenge. However, reconstitution of rCTB-free Dukoral with rCTB restored full protection. Parenteral immunization with Dukoral evoked strong systemic immunity without induction of mucosal immunity or protection from the challenge. These results suggest that both anti-bacterial and anti-toxic immunity are required for protection against V. cholerae-induced pneumonia, and this animal model is useful for pre-clinical evaluation of candidate cholera vaccines.

  2. The Population Structure of Vibrio cholerae from the Chandigarh Region of Northern India

    KAUST Repository

    Abd El Ghany, Moataz

    2014-07-24

    Background:Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century.Methodology/Principal Findings:Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII) and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST) distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA) identified 16 distinct clusters.Conclusions/Significance:The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

  3. Dynamics of Vibrio cholerae abundance in Austrian saline lakes, assessed with quantitative solid-phase cytometry

    OpenAIRE

    2015-01-01

    International audience; In order to elucidate the main predictors of Vibrio cholerae dynamics and to estimate the risk of Vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (CARD-FISH/ SPC) was applied in comparison to cultivation for water samples from the lake Neusiedler See, Austria and three shallow alkaline lakes over a period of 20 months. Vibrio cholerae attached to crustacean zoo-plankto...

  4. Diagnosing Cholera in The Young: A Review of W.H.O. Criteria.

    Directory of Open Access Journals (Sweden)

    Shuchita Gupta, Urmila Jhamb, Beena Uppal, Anita Chakraverti, S.K. Mittal

    2007-07-01

    Full Text Available This study was undertaken to study the occurrence of cholera in young children with a view to define theclinical criteria of diagnosis and endemicity of cholera in Delhi and to compare its clinical profile withrotavirus diarrhea. Hundred children below 3 years of age admitted with acute watery diarrhea wererecruited. The severity of diarrhea and degree of dehydration were noted. Stool specimens collected fromall cases were subjected to bacterial culture for identification of Vibrio cholerae and rotavirus detectionby ELISA and PAGE techniques. Both Vibrio cholerae and rotavirus were detected in 5, Vibrio choleraealone in 13 and rotavirus alone in 18 cases. Sixty-one percent cases of cholera occurred in children belowtwo years. Rice watery stools were seen only in 28% (5/18 cases of cholera. Three (3/13 cases withcholera alone and 6/18 with rotavirus alone had mild diarrhea. Moderate diarrhea occurred in 3/5 caseswith both pathogens, 6/13 with cholera alone and 7/18 with rotavirus alone. Severe diarrhea occurred in3/5 cases with both pathogens, 4/13 with cholera alone, and 5/18 cases with rotavirus alone. Milddehydration occurred in 3/5 and severe dehydration in 2/5 children with both pathogens. Only 3/13 childrenwith cholera alone and one child with rotavirus alone were severely dehydrated. It is concluded thatconsidering the diagnosis of cholera solely on clinical grounds and overlap between the clinical spectrumof cholera and rotavirus diarrhea would result in missing many cholera cases in a non-endemic area likeDelhi.

  5. Vibrio cholerae evades neutrophil extracellular traps by the activity of two extracellular nucleases.

    Directory of Open Access Journals (Sweden)

    Andrea Seper

    Full Text Available The Gram negative bacterium Vibrio cholerae is the causative agent of the secretory diarrheal disease cholera, which has traditionally been classified as a noninflammatory disease. However, several recent reports suggest that a V. cholerae infection induces an inflammatory response in the gastrointestinal tract indicated by recruitment of innate immune cells and increase of inflammatory cytokines. In this study, we describe a colonization defect of a double extracellular nuclease V. cholerae mutant in immunocompetent mice, which is not evident in neutropenic mice. Intrigued by this observation, we investigated the impact of neutrophils, as a central part of the innate immune system, on the pathogen V. cholerae in more detail. Our results demonstrate that V. cholerae induces formation of neutrophil extracellular traps (NETs upon contact with neutrophils, while V. cholerae in return induces the two extracellular nucleases upon presence of NETs. We show that the V. cholerae wild type rapidly degrades the DNA component of the NETs by the combined activity of the two extracellular nucleases Dns and Xds. In contrast, NETs exhibit prolonged stability in presence of the double nuclease mutant. Finally, we demonstrate that Dns and Xds mediate evasion of V. cholerae from NETs and lower the susceptibility for extracellular killing in the presence of NETs. This report provides a first comprehensive characterization of the interplay between neutrophils and V. cholerae along with new evidence that the innate immune response impacts the colonization of V. cholerae in vivo. A limitation of this study is an inability for technical and physiological reasons to visualize intact NETs in the intestinal lumen of infected mice, but we can hypothesize that extracellular nuclease production by V. cholerae may enhance survival fitness of the pathogen through NET degradation.

  6. Molecular characteristics and antibiotic resistance of Vibrio cholerae O139 in Shandong province

    Institute of Scientific and Technical Information of China (English)

    袁玉起

    2014-01-01

    Objective To investigate the molecular epidemiological characteristics and antibiotic resistance profiles of Vibrio cholerae O139 in Shandong province.Methods A total of 13 strains of V.cholerae O139(9 clinical strains and 4 environmental strains)isolated from cholera epidemics in Shandong province since 1997 were recovered and confirmed with serum agglutination and biochemical reaction.Pulsed-field gel electrophoresis(PFGE)was carried out for molecular subtyping.Virulence genes and

  7. The population structure of Vibrio cholerae from the Chandigarh Region of Northern India.

    Directory of Open Access Journals (Sweden)

    Moataz Abd El Ghany

    2014-07-01

    Full Text Available Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century.Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA identified 16 distinct clusters.The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

  8. Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

    Science.gov (United States)

    Augustijn, Ellen-Wien; Doldersum, Tom; Augustijn, Denie

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

  9. Modelling and control of cholera on networks with a common water source.

    Science.gov (United States)

    Shuai, Zhisheng; van den Driessche, P

    2015-01-01

    A mathematical model is formulated for the transmission and spread of cholera in a heterogeneous host population that consists of several patches of homogeneous host populations sharing a common water source. The basic reproduction number ℛ0 is derived and shown to determine whether or not cholera dies out. Explicit formulas are derived for target/type reproduction numbers that measure the control strategies required to eradicate cholera from all patches.

  10. Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments.

    Science.gov (United States)

    Madhusudana, Rao B; Surendran, P K

    2013-06-01

    Water and post-larvae samples from black tiger (Penaeus monodon) shrimp hatcheries; pond water, pond sediment and shrimp from aquaculture farms were screened for the presence of V. cholerae. A V. cholerae-duplex PCR method was developed by utilizing V. cholerae species specific sodB primers and ctxAB genes specific primers. Incidence of V. cholerae was not observed in shrimp hatchery samples but was noticed in aquaculture samples. The incidence of V. cholerae was higher in pond water (7.6%) than in pond sediment (5.2%). Shrimp head (3.6%) portion had relatively higher incidence than shrimp muscle (1.6%). All the V. cholerae isolates (n = 42) belonged to non-O1/non-O139 serogroup, of which 7% of the V. cholerae isolates were potentially cholera-toxigenic (ctx positive). All the ctx positive V. cholerae (n = 3) were isolated from the pond water. Since, cholera toxin (CT) is the major contributing factor for cholera gravis, it is proposed that the mere presence of non-O1/non-O139 V. cholerae need not be the biohazard criterion in cultured black tiger shrimp but only the presence of ctx carrying non-O1/non-O139 V. cholerae may be considered as potential public health risk.

  11. Rainfall mediations in the spreading of epidemic cholera

    Science.gov (United States)

    Righetto, L.; Bertuzzo, E.; Mari, L.; Schild, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2013-10-01

    Following the empirical evidence of a clear correlation between rainfall events and cholera resurgence that was observed in particular during the recent outbreak in Haiti, a spatially explicit model of epidemic cholera is re-examined. Specifically, we test a multivariate Poisson rainfall generator, with parameters varying in space and time, as a driver of enhanced disease transmission. The relevance of the issue relates to the key insight that predictive mathematical models may provide into the course of an ongoing cholera epidemic aiding emergency management (say, in allocating life-saving supplies or health care staff) or in evaluating alternative management strategies. Our model consists of a set of dynamical equations (SIRB-like i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals, and including a balance of Bacterial concentrations in the water reservoir) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water. These, in turn, are driven by rainfall washout of open-air defecation sites or cesspool overflows, hydrologic transport through waterways and by mobility of susceptible and infected individuals. We perform an a posteriori analysis (from the beginning of the epidemic in October 2010 until December 2011) to test the model reliability in predicting cholera cases and in testing control measures, involving vaccination and sanitation campaigns, for the ongoing epidemic. Even though predicting reliably the timing of the epidemic resurgence proves difficult due to rainfall inter-annual variability, we find that the model can reasonably quantify the total number of reported infection cases in the selected time-span. We then run a multi-seasonal prediction of the course of the epidemic until December 2015, to investigate conditions for further resurgences and endemicity of cholera in the region with a view to policies which may bring to

  12. Replication of Vibrio cholerae chromosome I in Escherichia coli: dependence on dam methylation

    DEFF Research Database (Denmark)

    Koch, Birgit; Ma, Xiaofang; Løbner-Olesen, Anders

    2010-01-01

    We successfully substituted Escherichia coli's origin of replication oriC with the origin region of Vibrio cholerae chromosome I (oriCIVc). Replication from oriCIVc initiated at a similar or slightly reduced cell mass compared to that of normal E. coli oriC. With respect to sequestration....... cholerae chromosome I replication, which similar to what is observed for E. coli. No hda homologue has been identified in V. cholerae yet. In V. cholerae, dam is essential for viability, whereas in E. coli, dam mutants are viable. Replacement of E. coli oriC with oriCIVc allowed us to specifically address...

  13. Survivability and molecular variation in Vibrio cholerae from epidemic sites in China.

    Science.gov (United States)

    Li, X Q; Wang, M; Deng, Z A; Shen, J C; Zhang, X Q; Liu, Y F; Cai, Y S; Wu, X W; DI, B

    2015-01-01

    The survival behaviour of Vibrio cholerae in cholera epidemics, together with its attributes of virulence-associated genes and molecular fingerprints, are significant for managing cholera epidemics. Here, we selected five strains representative of V. cholerae O1 and O139 involved in cholera events, examined their survival capacity in large volumes of water sampled from epidemic sites of a 2005 cholera outbreak, and determined virulence-associated genes and molecular subtype changes of the surviving isolates recovered. The five strains exhibited different survival capacities varying from 17 to 38 days. The virulence-associated genes of the surviving isolates remained unchanged, while their pulsotypes underwent slight variation. In particular, one waterway-isolated strain maintained virulence-associated genes and evolved to share the same pulsotype as patient strains, highlighting its role in the cholera outbreak. The strong survival capacity and molecular attributes of V. cholerae might account for its persistence in environmental waters and the long duration of the cholera outbreak, allowing effective control measures.

  14. In Silico Structural and Functional Annotation of Hypothetical Proteins of Vibrio cholerae O139

    Science.gov (United States)

    Islam, Md. Saiful; Shahik, Shah Md.; Sohel, Md.; Patwary, Noman I. A.

    2015-01-01

    In developing countries threat of cholera is a significant health concern whenever water purification and sewage disposal systems are inadequate. Vibrio cholerae is one of the responsible bacteria involved in cholera disease. The complete genome sequence of V. cholerae deciphers the presence of various genes and hypothetical proteins whose function are not yet understood. Hence analyzing and annotating the structure and function of hypothetical proteins is important for understanding the V. cholerae. V. cholerae O139 is the most common and pathogenic bacterial strain among various V. cholerae strains. In this study sequence of six hypothetical proteins of V. cholerae O139 has been annotated from NCBI. Various computational tools and databases have been used to determine domain family, protein-protein interaction, solubility of protein, ligand binding sites etc. The three dimensional structure of two proteins were modeled and their ligand binding sites were identified. We have found domains and families of only one protein. The analysis revealed that these proteins might have antibiotic resistance activity, DNA breaking-rejoining activity, integrase enzyme activity, restriction endonuclease, etc. Structural prediction of these proteins and detection of binding sites from this study would indicate a potential target aiding docking studies for therapeutic designing against cholera. PMID:26175663

  15. [Design and implementation of Geographical Information System on prevention and control of cholera].

    Science.gov (United States)

    Li, Xiu-jun; Fang, Li-qun; Wang, Duo-chun; Wang, Lu-xi; Li, Ya-pin; Li, Yan-li; Yang, Hong; Kan, Biao; Cao, Wu-chun

    2012-04-01

    To build the Geographical Information System (GIS) database for prevention and control of cholera programs as well as using management analysis and function demonstration to show the spatial attribute of cholera. Data from case reporting system regarding diarrhoea, vibrio cholerae, serotypes of vibrio cholerae at the surveillance spots and seafoods, as well as surveillance data on ambient environment and climate were collected. All the data were imported to system database to show the incidence of vibrio cholerae in different provinces, regions and counties to support the spatial analysis through the spatial analysis of GIS. The epidemic trends of cholera, seasonal characteristics of the cholera and the variation of the vibrio cholerae with times were better understood. Information on hotspots, regions and time of epidemics was collected, and helpful in providing risk prediction on the incidence of vibrio cholerae. The exploitation of the software can predict and simulate the spatio-temporal risks, so as to provide guidance for the prevention and control of the disease.

  16. Vibrio cholerae laboratory infection of the adult house fly Musca domestica.

    Science.gov (United States)

    El-Bassiony, G M; Luizzi, V; Nguyen, D; Stoffolano, J G; Purdy, A E

    2016-12-01

    The present study was designed to test the hypothesis that house flies may be capable of specifically harbouring ingested Vibrio cholerae in their digestive tracts. Flies were continuously fed green fluorescent protein (GFP)-labelled, non-O1/non-O139 environmental strains of V. cholerae. Bacterial burdens were quantitatively measured using plate counts and localization was directly observed using confocal microscopy. Vibrio cholerae were present in the fly alimentary canal after just 4 h, and reached a plateau of ∼10(7) colony-forming units (CFU)/fly after 5 days in those flies most tolerant of the pathogen. However, individual flies were resistant to the pathogen: one or more flies were found to carry V. cholerae CFU at each time-point examined. In flies carrying V. cholerae, the pathogen was predominantly localized to the midgut rather than the rectal space or crop. The proportion of house flies carrying V. cholerae in the midgut was dose-dependent: the continuous ingestion of a concentrated, freshly prepared dose of V. cholerae increased the likelihood that fluorescent cells would be observed. However, V. cholerae may be a transient inhabitant of the house fly. This work represents the first demonstration that V. cholerae can inhabit the house fly midgut, and provides a platform for future studies of host, pathogen and environmental mediators of the successful colonization of this disease vector.

  17. Bactericidal Efficacy of Allium sativum (garlic Against Multidrug Resistant Vibrio cholerae O1 Epidemic Strains

    Directory of Open Access Journals (Sweden)

    Pramod Kumar

    2016-09-01

    Full Text Available In recent years, emerging trend of antibiotic resistance in Vibrio cholerae associated with cholera epidemics is a matter of serious concern for the management of the disease. Indiscriminate use of antibiotics generally results in selection of antibiotic resistant strains. Introduction of newer antibiotics is a challenging task for the researchers as bacteria soon attain resistance. Therefore, identifying natural compounds of medicinal importance for control of cholera would be the best alternative. Garlic (Allium sativum was recognised for many centuries in early Chinese, Egyptian and Indian civilisations as an herbal or traditional medicine. In present study, garlic was selected for screening of antimicrobial efficacy against V. cholerae. A total of 55 V. cholerae strains isolated from various outbreaks/epidemics were subjected to antimicrobial testing as per CLSI, USA 2010 guidelines. Antimicrobial screening of garlic extract was performed against all the multidrug resistant strains of V. cholerae. The garlic extracts showed antibacterial activity against all the V. cholerae strains tested, irrespective of their origin, multidrug resistance and virulence. Antibacterial efficacy of garlic on V. cholerae was also evident from in vivo study on sealed adult mice model. Thus, the Garlic extract harnesses the potential to control infection of multidrug resistant V. cholerae, especially in outbreak like situations in remote and under developed areas where drug supply itself is a challenge

  18. Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

    Science.gov (United States)

    Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

    2014-12-01

    A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

  19. Survival and proliferation of the lysogenic bacteriophage CTXΦ in Vibrio cholerae

    Institute of Scientific and Technical Information of China (English)

    Fenxia; Fan; Biao; Kan

    2015-01-01

    The lysogenic phage CTXΦ of Vibrio cholerae can transfer the cholera toxin gene both horizontally(inter-strain) and vertically(cell proliferation). Due to its diversity in form and species, the complexity of regulatory mechanisms, and the important role of the infection mechanism in the production of new virulent strains of V.cholerae, the study of the lysogenic phage CTXΦ has attracted much attention. Based on the progress of current research, the genomic features and their arrangement, the host-dependent regulatory mechanisms of CTXΦ phage survival, proliferation and propagation were reviewed to further understand the phage’s role in the evolutionary and epidemiological mechanisms of V. cholerae.

  20. Hurricanes, climate change and the cholera epidemic in Puerto Rico of 1855-1856.

    Science.gov (United States)

    Christenson, Bernard

    2008-01-01

    Hurricanes and global climate changes may affect the environmental factors of cholera dynamics in warm coastal areas, vulnerable to seasonal or sporadic outbreaks. The cholera epidemic of Puerto Rico in 1855-1856 had a profound effect on the Puerto Rican society; but it was not influenced by any climatic events, such as preceding hurricanes or storms based on past documentary sources. Particularly, the environmental non-toxigenic strains of Vibrio Cholerae in Puerto Rican water sources can maintain their pathogenic potential for sporadic or erratic toxigenic cholera outbreaks--if a "perfect storm" ever occurs.

  1. Genomics of immune response to typhoid and cholera vaccines.

    Science.gov (United States)

    Majumder, Partha P

    2015-06-19

    Considerable variation in antibody response (AR) was observed among recipients of an injectable typhoid vaccine and an oral cholera vaccine. We sought to find whether polymorphisms in genes of the immune system, both innate and adaptive, were associated with the observed variation in response. For both vaccines, we were able to discover and validate several polymorphisms that were significantly associated with immune response. For the typhoid vaccines, these polymorphisms were on genes that belonged to pathways of polysaccharide recognition, signal transduction, inhibition of T-cell proliferation, pro-inflammatory signalling and eventual production of antimicrobial peptides. For the cholera vaccine, the pathways included epithelial barrier integrity, intestinal homeostasis and leucocyte recruitment. Even though traditional wisdom indicates that both vaccines should act as T-cell-independent antigens, our findings reveal that the vaccines induce AR using different pathways.

  2. 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; Gerner-Smidt, Peter

    2011-11-01

    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.

  3. Mathematical analysis of a cholera model with public health interventions.

    Science.gov (United States)

    Mwasa, A; Tchuenche, J M

    2011-09-01

    Cholera, an acute gastro-intestinal infection and a waterborne disease continues to emerge in developing countries and remains an important global health challenge. We formulate a mathematical model that captures some essential dynamics of cholera transmission to study the impact of public health educational campaigns, vaccination and treatment as control strategies in curtailing the disease. The education-induced, vaccination-induced and treatment-induced reproductive numbers R(E), R(V), R(T) respectively and the combined reproductive number R(C) are compared with the basic reproduction number R(0) to assess the possible community benefits of these control measures. A Lyapunov functional approach is also used to analyse the stability of the equilibrium points. We perform sensitivity analysis on the key parameters that drive the disease dynamics in order to determine their relative importance to disease transmission and prevalence. Graphical representations are provided to qualitatively support the analytical results.

  4. Activation of a pro-survival pathway IL-6/JAK2/STAT3 contributes to glial fibrillary acidic protein induction during the cholera toxin-induced differentiation of C6 malignant glioma cells.

    Science.gov (United States)

    Shu, Minfeng; Zhou, Yuxi; Zhu, Wenbo; Wu, Sihan; Zheng, Xiaoke; Yan, Guangmei

    2011-06-01

    Differentiation-inducing therapy has been proposed to be a novel potential approach to treat malignant gliomas. Glial fibrillary acidic protein (GFAP) is a well-known specific astrocyte biomarker and acts as a tumor suppressor gene (TSG) in glioma pathogenesis. Previously we reported that a traditional biotoxin cholera toxin could induce malignant glioma cell differentiation characterized by morphologic changes and dramatic GFAP expression. However, the molecular mechanisms underlying GFAP induction are still largely unknown. Here we demonstrate that an oncogenic pathway interleukin-6/janus kinase-2/signal transducer and activator of transcription 3 (IL-6/JAK2/STAT3) cascade mediates the cholera toxin-induced GFAP expression. Cholera toxin dramatically stimulated GFAP expression at the transcriptional level in C6 glioma cells. Meanwhile, phosphorylation of STAT3 and JAK2 was highly induced in a time-dependent manner after cholera toxin incubation, whereas no changes of STAT3 and JAK2 were observed. Furthermore, the IL-6 gene was quickly induced by cholera toxin and subsequent IL-6 protein secretion was stimulated. Importantly, exogenous recombinant rat IL-6 can also induce phosphorylation of STAT3 concomitant with GFAP expression while JAK2 specific inhibitor AG490 could effectively block both cholera toxin- and IL-6-induced GFAP expression. Given that the methylation of the STAT3 binding element can suppress GFAP expression, we detected the methylation status of the critical recognition sequence of STAT3 in the promoter of GFAP gene (-1518 ∼ -1510) and found that it was unmethylated in C6 glioma cells. In addition, neither DNA methyltransferase1 (DNMT1) inhibitor 5-Aza-2'-deoxycytidine (5-AZa-CdR) nor silencing DNMT1 can stimulate GFAP expression, indicating that the loss of GFAP expression in C6 cells is not caused by its promoter hypermethylation. Taken together, our findings suggest that activation of a pro-survival IL-6/JAK2/STAT3 cascade contributes to

  5. [Functional analysis of promoters of Vibrio cholerea typing phage VP1 with reporter system].

    Science.gov (United States)

    Li, Yan-Ping; Liang, Wei-Li; Wang, Duo-Chun; Qi, Guo-Ming; Kan, Biao; Gao, Shou-Yi; Liu, Yan-Qing

    2005-12-01

    Phage VP1 infects and lyses Vibrio cholerae. The VP1 genome is a circular double-strand DNA and its size is 32176 base pairs. Analysis of the sequence of the VP1 genome revealed the presence of 15 putative promoter sequence. The activities of these putative promoters in V. cholerae were assayed by transformation of reporter gene plasmid and phage infection together. Promoter regions were ligated into pRS1274/BamH I/EcoR I. Then transformed into E. coli JM109 and all of clone display blue. The recombinant plasmids were transformed into V. cholerae 7743 deltaZ by electroporation, then bacteriophage VP1 infect transformant. The time-course expressing lacZ gene and detecting change of beta-galactosidase enzyme activity in V. cholerae transformants at latent period, indicated P17 probably is a early promoter; P2 and P3 and P9 etc are medium-term promoters; P18 is a late promoter.

  6. Intranasal immunization with recombinant toxin-coregulated pilus and cholera toxin B subunit protects rabbits against Vibrio cholerae O1 challenge.

    Science.gov (United States)

    Kundu, Juthika; Mazumder, Rupa; Srivastava, Ranjana; Srivastava, Brahm S

    2009-07-01

    Intranasal immunization, a noninvasive method of vaccination, has been found to be effective in inducing systemic and mucosal immune responses. The present study was aimed at investigating the efficacy of intranasal immunization in inducing mucosal immunity in experimental cholera by subunit recombinant protein vaccines from Vibrio cholerae O1. The structural genes encoding toxin-coregulated pilus A (TcpA) and B subunit of cholera toxin (CtxB) from V. cholerae O1 were cloned and expressed in Escherichia coli. Rabbits were immunized intranasally with purified TcpA and CtxB alone or a mixture of TcpA and CtxB. Immunization with TcpA and CtxB alone conferred, respectively, 41.1% and 70.5% protection against V. cholerae challenge, whereas immunization with a mixture of both antigens conferred complete (100%) protection, as assayed in the rabbit ileal loop model. Serum titers of immunoglobulin G (IgG) antibodies to TcpA and CtxB, and anti-TcpA- and anti-CtxB-specific sIgA in intestinal lavage of vaccinated animals were found to be significantly elevated compared with unimmunized controls. Vibriocidal antibodies were detected at remarkable levels in rabbits receiving TcpA antigen and their titers correlated with protection. Thus, mucosal codelivery of pertinent cholera toxoids provides enhanced protection against experimental cholera.

  7. OmpU as a biomarker for rapid discrimination between toxigenic and epidemic Vibrio cholerae O1/O139 and non-epidemic Vibrio cholerae in a modified MALDI-TOF MS assay

    NARCIS (Netherlands)

    Paauw, A.; Trip, H.; Niemcewicz, M.; Sellek, R.; Heng, J.M.E.; Mars-Groenendijk, R.H.; Jong, A.L. de; Majchrzykiewicz-Koehorst, J.A.; Olsen, J.S.; Tsivtsivadze, E.

    2014-01-01

    Background Cholera is an acute diarrheal disease caused by Vibrio cholerae. Outbreaks are caused by a genetically homogenous group of strains from serogroup O1 or O139 that are able to produce the cholera toxin. Rapid detection and identification of these epidemic strains is essential for an effecti

  8. Ion-swimming speed variation of Vibrio cholerae cells

    Indian Academy of Sciences (India)

    Anindito Sen; Ranjan K Nandi; Amar N Ghosh

    2005-09-01

    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 the sodium ions in the medium and then plateaus. The range within which the swimming speed attains saturation is approximately the same at different temperatures.

  9. 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.

  10. Immunization of Mice With Vibrio cholerae Outer-Membrane Vesicles Protects Against Hyperinfectious Challenge and Blocks Transmission

    OpenAIRE

    Bishop, Anne L.; Tarique, Abdullah A.; Patimalla, Bharathi; Calderwood, Stephen B.; Qadri, Firdausi; Camilli, Andrew

    2011-01-01

    Background. Vibrio cholerae excreted by cholera patients is “hyperinfectious” (HI), which can be modeled by passage through infant mice. Immunization of adult female mice with V. cholerae outer-membrane vesicles (OMVs) passively protects suckling mice from challenge. Although V. cholerae is unable to colonize protected pups, the bacteria survive passage and have the potential to be transmitted to susceptible individuals. Here, we investigated the impact of OMV immunization and the HI state on...

  11. Comparative phenotypic characterization of Vibrio cholerae isolates collected from aquatic environments of Georgia.

    Science.gov (United States)

    Kokashvili, T; Elbakidze, T; Jaiani, E; Janelidze, N; Kamkamidze, G; Whitehouse, C; Huq, A; Tediashvili, M

    2013-11-01

    Vibrio cholerae is ubiquitous in aquatic environment inhabiting marine, fresh and brackish waters. V. cholerae serotypes O1 and O139 cause the devastating diarrheal disease cholera, which is often fatal without proper treatment. Little is known regarding the abundance and diversity of clinically important nonhalophilic vibrios in the South Caucasus region, particularly in Georgia. Here we provide the data on the Georgian environmental strains of V. cholerae isolated in 2006-2009 years from the coastal waters of the Black Sea and inland water reservoirs near Tbilisi. In total, 846 V. cholerae strains were collected from the water samples, most of them (705 strains) obtained from fresh water lakes. Isolation pattern of V. cholerae showed obvious seasonality with the highest isolation rates in late summer - early autumn. Twenty-nine isolates of V. cholerae were attributed to the O1 serotype based on serological studies and PCR identification and were further grouped by biochemical properties into classical and El Tor biotypes as well as hybrids. The study of antibiotic susceptibility profiles for V. cholerae isolates showed that 95% were sensitive to tetracycline, 91% to doxycycline, and 91% to ciprofloxacin. Interestingly, the freshwater isolates appeared to be more resistant to antibiotics than the Black Sea isolates. Among Black Sea isolates of V. cholerae toxigenic strains of O1 serotype revealed higher antibiotic resistance compared to non- O1/non-O139 isolates. In addition, V. cholerae O1 and non- O1/non-O139 isolates differed by phage susceptibility profiles, with higher diversity within the population of environmental non-O1/non-O139 V. cholerae isolates.

  12. CHANGING EPIDEMIOLOGICAL TREND OF CHOLERA IN WEST BENGAL: THE GIANT IS BACK

    Directory of Open Access Journals (Sweden)

    Indrani

    2013-11-01

    Full Text Available ABSTRACT: Choler a is a devastating diarrheal disease caused by V. cholera. Two biotypes of V. cholerae O1, classical and El - Tor, are distinguished. Each biotype is further subdivided into two serotypes, termed Inaba and Ogawa. As large deltaic areas of the Ganges and Brah maputra rivers are considered to be the homeland of cholera, objective of our study was to detect the circulating strain of Vibrio causing Cholera outbreaks in different pockets of West Bengal. Water samples collected from the water sources of the affected areas and stool samples and or rectal swabs of suspected cases were tested according to standard bacteriological protocol. In July 2008, Cholera outbreak was caused by Vibrio cholera e O1 El - Tor Inaba serotype in Darjeeling district affecting 176 persons. Mean age of the affected people was 15years. Thereafter in the June, 2010, there was an outbreak of Vibrio cholerae El Tor Ogawa affecting 87 people in Maldah. Mean age of the cases was 25years. Similar type of Vibrio cholerae O1 El - Tor Ogawa strain was is olated in the outbreak of June to September 2012 in Maldah with lower mean age of cases i.e.7years. A total of 93 patients suffered from Cholera during this outbreak. Cholera outbreak in West Bengal was caused by classical Vibrio cholerae O1 Ogawa serotype affecting 803 people in North 24 Paragana in October, 2013. Mean age of the patients was 31year. As classical Vibrio causes more severe disease than El - Tor, its reemergence with multidrug resistant properties is no doubt an upcoming threat

  13. 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.

  14. Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide

    Directory of Open Access Journals (Sweden)

    Badshah Syed Lal

    2016-01-01

    Full Text Available A molecular dynamics (MD simulation study of the enzymatic portion of cholera toxin; cholera toxin A-1 polypeptide (CTA1 was performed at 283, 310 and 323 K. From total energy analysis it was observed that this toxin is stable thermodynamically and these outcomes were likewise confirmed by root mean square deviations (RMSD investigations. The Cα root mean square fluctuation (RMSF examinations revealed that there are a number of residues inside CTA1, which can be used as target for designing and synthesizing inhibitory drugs, in order to inactivate cholera toxin inside the human body. The fluctuations in the radius of gyration and hydrogen bonding in CTA1 proved that protein unfolding and refolding were normal routine phenomena in its structure at all temperatures. Solvent accessible surface area study identified the hydrophilic nature of the CTA1, and due to this property it can be a potential biological weapon. The structural identification (STRIDE algorithm for proteins was successfully used to determine the partially disordered secondary structure of CTA1. On account of this partially disordered secondary structure, it can easily deceive the proteolytic enzymes of the endoplasmic reticulum of host cells.

  15. Blood Group O-Dependent Cellular Responses to Cholera Toxin: Parallel Clinical and Epidemiological Links to Severe Cholera.

    Science.gov (United States)

    Kuhlmann, F Matthew; Santhanam, Srikanth; Kumar, Pardeep; Luo, Qingwei; Ciorba, Matthew A; Fleckenstein, James M

    2016-08-03

    Because O blood group has been associated with more severe cholera infections, it has been hypothesized that cholera toxin (CT) may bind non-O blood group antigens of the intestinal mucosae, thereby preventing efficient interaction with target GM1 gangliosides required for uptake of the toxin and activation of cyclic adenosine monophosphate (cAMP) signaling in target epithelia. Herein, we show that after exposure to CT, human enteroids expressing O blood group exhibited marked increase in cAMP relative to cells derived from blood group A individuals. Likewise, using CRISPR/Cas9 engineering, a functional group O line (HT-29-A(-/-)) was generated from a parent group A HT-29 line. CT stimulated robust cAMP responses in HT-29-A(-/-) cells relative to HT-29 cells. These findings provide a direct molecular link between blood group O expression and differential cellular responses to CT, recapitulating clinical and epidemiologic observations.

  16. Toxin(s), Other Than Cholera Toxin, Produced by Environmental Non O1 Non O139 Vibrio cholerae

    Institute of Scientific and Technical Information of China (English)

    Kohinur Begum; Chowdhury R. Ahsan; Mohammad Ansaruzzaman; Dilip K. Dutta; Qazi S.Ahmad; Kaisar A. Talukder

    2006-01-01

    A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analysis.Eighteen representative strains were tested for enterotoxin production using a rabbit ileal loop model, of which live cells of 8 strains and culture filtrates of 6 strains produced fluid accumulation in ileal loops. However, none of them produced heat stable toxin (ST), as detected by suckling mouse assay. On the other hand, 15% of isolates produced cytotoxin as detected by the Chinese Hamster Ovary (CHO) cell assay. Fifty times concentrated culture filtrates of the representative strains did not give any precipitin band against the anti-cholera toxin, suggesting the strains produced an enterotoxin, which is antigenically different from known cholera toxin (CT). Eighty percent of the total isolates were found to be positive for heat labile haemolysin detected by tube method, whereas, 39% were found positive by the Christie-Atkins-Munch-Petersen (CAMP) method. However, 87% of the isolates were positive for haemagglutinin/protease and all of the strains were positive for mannose-sensitive-haemagglutinin assay.

  17. The antigenic relationship between Brettanomyces-Debaryomyces strains and the Salmonella cholerae-suis O antigen.

    Science.gov (United States)

    Aksoycan, N; Sağanak, I; Wells, G

    1978-01-01

    The immune sera for Brettanomyces lambicus, B. claussenii, Debaryomyces hansenii and D. marama agglutinated Salmonella cholerae-suis (0:6(2), 7). The immune serum for S. cholerae-suis agglutinated B. lambicus, B. clausenni, D. hansenii and D. marama. Absorption and agglutination cross-tested demonstrated common antigen factor(s) in the tested yeasts and Salmonella 0:7 antigen.

  18. Model of Cholera Forecasting Using Artificial Neural Network in Chabahar City, Iran

    Directory of Open Access Journals (Sweden)

    Pezeshki

    2016-02-01

    Full Text Available Background Cholera as an endemic disease remains a health issue in Iran despite decrease in incidence. Since forecasting epidemic diseases provides appropriate preventive actions in disease spread, different forecasting methods including artificial neural networks have been developed to study parameters involved in incidence and spread of epidemic diseases such as cholera. Objectives In this study, cholera in rural area of Chabahar, Iran was investigated to achieve a proper forecasting model. Materials and Methods Data of cholera was gathered from 465 villages, of which 104 reported cholera during ten years period of study. Logistic regression modeling and correlate bivariate were used to determine risk factors and achieve possible predictive model one-hidden-layer perception neural network with backpropagation training algorithm and the sigmoid activation function was trained and tested between the two groups of infected and non-infected villages after preprocessing. For determining validity of prediction, the ROC diagram was used. The study variables included climate conditions and geographical parameters. Results After determining significant variables of cholera incidence, the described artificial neural network model was capable of forecasting cholera event among villages of test group with accuracy up to 80%. The highest accuracy was achieved when model was trained with variables that were significant in statistical analysis describing that the two methods confirm the result of each other. Conclusions Application of artificial neural networking assists forecasting cholera for adopting protective measures. For a more accurate prediction, comprehensive information is required including data on hygienic, social and demographic parameters.

  19. Dynamics of Vibrio cholerae abundance in Austrian saline lakes, assessed with quantitative solid-phase cytometry.

    Science.gov (United States)

    Schauer, Sonja; Jakwerth, Stefan; Bliem, Rupert; Baudart, Julia; Lebaron, Philippe; Huhulescu, Steliana; Kundi, Michael; Herzig, Alois; Farnleitner, Andreas H; Sommer, Regina; Kirschner, Alexander

    2015-11-01

    In order to elucidate the main predictors of Vibrio cholerae dynamics and to estimate the risk of Vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (CARD-FISH/SPC) was applied in comparison to cultivation for water samples from the lake Neusiedler See, Austria and three shallow alkaline lakes over a period of 20 months. Vibrio cholerae attached to crustacean zooplankton was quantified via FISH and epifluorescence microscopy. Concentrations obtained by CARD-FISH/SPC were significantly higher than those obtained by culture in 2011, but were mostly of similar magnitude in 2012. Maximum cell numbers were 1.26 × 10(6) V. cholerae per L in Neusiedler See and 7.59 × 10(7) V. cholerae per L in the shallow alkaline lakes. Only on a few occasions during summer was the crustacean zooplankton the preferred habitat for V. cholerae. In winter, V. cholerae was not culturable but could be quantified at all sites with CARD-FISH/SPC. Beside temperature, suspended solids, zooplankton and ammonium were the main predictors of V. cholerae abundance in Neusiedler See, while in the shallow alkaline lakes it was organic carbon, conductivity and phosphorus. Based on the obtained concentrations a first estimation of the health risk for visitors of the lake could be performed.

  20. Satellite Based Assessment of Hydroclimatic Conditions Related to Cholera in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Antarpreet Jutla

    Full Text Available Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008.Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began.Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

  1. Toxigenic Vibrio cholerae identified in estuaries of Tanzania using PCR techniques.

    Science.gov (United States)

    Dalusi, Lucy; Lyimo, Thomas J; Lugomela, Charles; Hosea, Ken M M; Sjöling, Sara

    2015-03-01

    The current study assessed the occurrence of the Vibrio cholerae serogroups O1 and O139 in environmental samples along salinity gradients in three selected estuaries of Tanzania both through culture independent methods and by cultured bacteria. Occurrence of V. cholerae was determined by PCR targeting the V. cholerae outer membrane protein gene ompW. Furthermore, the presence of toxigenic strains and serogroups O1 and O139 was determined using multiplex PCR with specific primers targeting the cholera toxin gene subunit A, ctxA, and serotype specific primers, O1-rfb and O139-rfb, respectively. Results showed that V. cholerae occurred in approximately 10% (n = 185) of both the environmental samples and isolated bacteria. Eight of the bacteria isolates (n = 43) were confirmed as serogroup O1 while one belonged to serogroup O139, the first reported identification of this epidemic strain in East African coastal waters. All samples identified as serogroup O1 or O139 and a number of non-O1/O139 strains were ctxA positive. This study provides in situ evidence of the presence of pathogenic V. cholerae O1 and O139 and a number of V. cholerae non-O1/O139 that carry the cholera toxin gene in estuaries along the coast of Tanzania.

  2. Small RNA target genes and regulatory connections in the Vibrio cholerae quorum sensing system

    DEFF Research Database (Denmark)

    Hammer, Brian K; Svenningsen, Sine Lo

    2011-01-01

    The two-component quorum sensing (QS) system, first described in the marine bacterium Vibrio harveyi and evolutionarily conserved among members of the genus Vibrio, has been best studied in the human pathogen Vibrio cholerae (1, 2). In the V. cholerae QS system, the response to the accumulation...

  3. Survival and distribution of Vibrio cholerae in a tropical rain forest stream

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Rosas, N. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico). Microbial Ecology Lab.; Hazen, T.C. [E.I. DuPont de Nemours and Co., Aiken, SC (United States). Savannah River Lab.

    1988-12-31

    For 12 months Vibrio cholerae and fecal coliforms were monitored along with 9 other water quality parameters at 12 sites in a rain forest watershed in Puerto Rico. Densities of V. cholerae and fecal coliforms were not significantly correlated even though the highest densities of both bacteria were found at a sewage outfall. High densities of V. cholerae were also found at pristine sites high in the watershed. V. cholerae and Escherichia coli were inoculated into membrane diffusion chambers, placed at two sites and monitored for 5 days on two different occasions. Two different direct count methods indicated that the density of E. coli and V. cholerae did not change significantly during the course of either study. Physiological activity, as measured by INT-reduction and relative nucleic acid composition declined for E. coli during the first 12 h then increased and remained variable during the remainder of the study. V. cholerae activity, as measured by relative nucleic acid concentrations, remained high and unchanged for the entire study. INT-reduction in V. cholerae declined initially but regained nearly all of it`s original activity within 48 h. This study suggests that V. cholerae is an indigenous organism in tropical freshwaters and that assays other than fecal coliforms or E. coli must be used for assessing public health risk in tropical waters.

  4. The complete genomic analysis of an imported Vibrio cholerae from Myanmar in southwest China.

    Science.gov (United States)

    Liao, Feng; Pang, Bo; Fu, Xiaoqing; Xu, Wen; Kan, Biao; Jing, Huaiqi; Gu, Wenpeng

    2016-10-01

    We sequenced and analyzed an imported Vibrio cholerae from Mynamar in 2011 by using whole genome sequencing method in Yunnan Province, southwest China. Other 3 isolates of V. cholerae in Yunnan were also sequenced for comparing purpose. Illumina Hiseq2500 was used and the sequencing results were assembled and annotated. The comparative genomic analysis was also performed with 101 reference strains from China and abroad. The results showed the imported V. cholerae (YN2011004) had two chromosomes and one plasmid; chr1 contained 2727 predicted genes, and 958 genes for chr2. Phylogenomic tree results showed YN2011004 belonged to the seventh pandemic strain, clustered into wave 3 and clade 3B. The strain had the highly homology with SN083 and 4remapscaff isolated in 2010 from other parts of China, and clustered with SN117, VC50 remapscaff, VC57 remapscaff and SN034. These references V. cholerae mostly isolated from coastal areas of China in 2008. For the other 3 strains' comparison, it suggested that V. cholerae in 1990s in Yunnan had the close relationship with the prevalence of cholera in Southeast Asia. Therefore, we thought that the cholera in Yunnan was consistent with the epidemic trend of China, being the "sink" for external source and also acted as a "source" for spread. Moreover, we considered that the imported V. cholerae from Myanmar in 2011 actually was the exported strain from China, and it provided us a new sight for the bacterial change and evolution.

  5. Whole-Genome Enrichment Provides Deep Insights into Vibrio cholerae Metagenome from an African River.

    Science.gov (United States)

    Vezzulli, L; Grande, C; Tassistro, G; Brettar, I; Höfle, M G; Pereira, R P A; Mushi, D; Pallavicini, A; Vassallo, P; Pruzzo, C

    2016-11-25

    The detection and typing of Vibrio cholerae in natural aquatic environments encounter major methodological challenges related to the fact that the bacterium is often present in environmental matrices at very low abundance in nonculturable state. This study applied, for the first time to our knowledge, a whole-genome enrichment (WGE) and next-generation sequencing (NGS) approach for direct genotyping and metagenomic analysis of low abundant V. cholerae DNA (V. cholerae metagenomic DNA via hybridization. An enriched V. cholerae metagenome library was generated and sequenced on an Illumina MiSeq platform. Up to 1.8 × 10(7) bp (4.5× mean read depth) were found to map against V. cholerae reference genome sequences representing an increase of about 2500 times in target DNA coverage compared to theoretical calculations of performance for shotgun metagenomics. Analysis of metagenomic data revealed the presence of several V. cholerae virulence and virulence associated genes in river water including major virulence regions (e.g. CTX prophage and Vibrio pathogenicity island-1) and genetic markers of epidemic strains (e.g. O1-antigen biosynthesis gene cluster) that were not detectable by standard culture and molecular techniques. Overall, besides providing a powerful tool for direct genotyping of V. cholerae in complex environmental matrices, this study provides a 'proof of concept' on the methodological gap that might currently preclude a more comprehensive understanding of toxigenic V. cholerae emergence from natural aquatic environments.

  6. Epidemiological description of unmitigated cholera epidemics in 19th century Denmark

    DEFF Research Database (Denmark)

    Phelps, Matthew David; Perner, Mads Linnet; Davidsen, Emma;

    Background. Cholera epidemics devastated 19th century European cities in multiple outbreaks during 1830-1900. Most Danish cities experienced only a single epidemic in 1853 and detailed data are available. This uniquely allows study of unmitigated epidemic cholera in a fully susceptible population...

  7. Production of Antibody Raised Against Lipopolysaccharide (LPS of Vibrio Cholerae Non-O1

    Directory of Open Access Journals (Sweden)

    H Shirzad

    2008-07-01

    Full Text Available Background: Cholera, an infectious disease caused by Vibrio cholerae, is primarily transmitted by ingestion of contaminated food or water. In severe cases, cholera may lead to severe dehydration, metabolic acidosis, and ultimately, hypovolemic shock and death. Methods: In this study V.cholerae non-O1 was cultured in suitable media. LPS was extracted from the surface of  bacteria by hot phenol-water method and then purified by high-speed centrifugation. For production of specific antibody against LPS, white newzeland rabbits were first immunized by whole cell bacteria and then immunized with highly purified LPS. The titre of the antiserum was determined by ELISA for each serogroup. Results: Results presented in this study indicate that serum anti-LPS antibodies raised against purified LPS of V.cholerae non-O1 can detect V.cholerae non-O1 .Conclusion: This antibody had low cross reactivity with V.cholerae O1, serotype Inaba or Ogawa. So, this antibody can be used for for detection of V. cholerae non-O1.

  8. Environmental factor analysis of cholera in China using remote sensing and geographical information systems.

    Science.gov (United States)

    Xu, M; Cao, C X; Wang, D C; Kan, B; Xu, Y F; Ni, X L; Zhu, Z C

    2016-04-01

    Cholera is one of a number of infectious diseases that appears to be influenced by climate, geography and other natural environments. This study analysed the environmental factors of the spatial distribution of cholera in China. It shows that temperature, precipitation, elevation, and distance to the coastline have significant impact on the distribution of cholera. It also reveals the oceanic environmental factors associated with cholera in Zhejiang, which is a coastal province of China, using both remote sensing (RS) and geographical information systems (GIS). The analysis has validated the correlation between indirect satellite measurements of sea surface temperature (SST), sea surface height (SSH) and ocean chlorophyll concentration (OCC) and the local number of cholera cases based on 8-year monthly data from 2001 to 2008. The results show the number of cholera cases has been strongly affected by the variables of SST, SSH and OCC. Utilizing this information, a cholera prediction model has been established based on the oceanic and climatic environmental factors. The model indicates that RS and GIS have great potential for designing an early warning system for cholera.

  9. 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

  10. Picomolar inhibition of cholera toxin by a pentavalent ganglioside GM1os-calix[5]arene

    NARCIS (Netherlands)

    Garcia-Hartjes, J.; Bernardi, S.; Weijers, C.A.G.M.; Wennekes, T.; Gilbert, M.; Sansone, F.; Casnati, A.; Zuilhof, H.

    2013-01-01

    Cholera toxin (CT), the causative agent of cholera, displays a pentavalent binding domain that targets the oligosaccharide of ganglioside GM1 (GM1os) on the periphery of human abdominal epithelial cells. Here, we report the first GM1os-based CT inhibitor that matches the valency of the CT binding do

  11. Hierarchical Bayesian modeling of the space-time diffusion patterns of cholera epidemic in Kumasi, Ghana

    NARCIS (Netherlands)

    Osei, Frank B.; Duker, Alfred A.; Stein, Alfred

    2011-01-01

    This study analyses the joint effects of the two transmission routes of cholera on the space-time diffusion dynamics. Statistical models are developed and presented to investigate the transmission network routes of cholera diffusion. A hierarchical Bayesian modelling approach is employed for a joint

  12. Cholera Transmission in Ouest Department of Haiti: Dynamic Modeling and the Future of the Epidemic

    Science.gov (United States)

    Kirpich, Alexander; Weppelmann, Thomas A.; Yang, Yang; Ali, Afsar; Morris, J. Glenn; Longini, Ira M.

    2015-01-01

    In the current study, a comprehensive, data driven, mathematical model for cholera transmission in Haiti is presented. Along with the inclusion of short cycle human-to-human transmission and long cycle human-to-environment and environment-to-human transmission, this novel dynamic model incorporates both the reported cholera incidence and remote sensing data from the Ouest Department of Haiti between 2010 to 2014. The model has separate compartments for infectious individuals that include different levels of infectivity to reflect the distribution of symptomatic and asymptomatic cases in the population. The environmental compartment, which serves as a source of exposure to toxigenic V. cholerae, is also modeled separately based on the biology of causative bacterium, the shedding of V. cholerae O1 by humans into the environment, as well as the effects of precipitation and water temperature on the concentration and survival of V. cholerae in aquatic reservoirs. Although the number of reported cholera cases has declined compared to the initial outbreak in 2010, the increase in the number of susceptible population members and the presence of toxigenic V. cholerae in the environment estimated by the model indicate that without further improvements to drinking water and sanitation infrastructures, intermittent cholera outbreaks are likely to continue in Haiti. PMID:26488620

  13. The role of socioeconomic status in longitudinal trends of cholera in Matlab, Bangladesh, 1993-2007.

    Science.gov (United States)

    Root, Elisabeth Dowling; Rodd, Joshua; Yunus, Mohammad; Emch, Michael

    2013-01-01

    There has been little evidence of a decline in the global burden of cholera in recent years as the number of cholera cases reported to WHO continues to rise. Cholera remains a global threat to public health and a key indicator of lack of socioeconomic development. Overall socioeconomic development is the ultimate solution for control of cholera as evidenced in developed countries. However, most research has focused on cross-county comparisons so that the role of individual- or small area-level socioeconomic status (SES) in cholera dynamics has not been carefully studied. Reported cases of cholera in Matlab, Bangladesh have fluctuated greatly over time and epidemic outbreaks of cholera continue, most recently with the introduction of a new serotype into the region. The wealth of longitudinal data on the population of Matlab provides a unique opportunity to explore the impact of socioeconomic status and other demographic characteristics on the long-term temporal dynamics of cholera in the region. In this population-based study we examine which factors impact the initial number of cholera cases in a bari at the beginning of the 0139 epidemic and the factors impacting the number of cases over time. Cholera data were derived from the ICDDR,B health records and linked to socioeconomic and geographic data collected as part of the Matlab Health and Demographic Surveillance System. Longitudinal zero-inflated Poisson (ZIP) multilevel regression models are used to examine the impact of environmental and socio-demographic factors on cholera counts across baris. Results indicate that baris with a high socioeconomic status had lower initial rates of cholera at the beginning of the 0139 epidemic (γ(01) = -0.147, p = 0.041) and a higher probability of reporting no cholera cases (α(01) = 0.156, p = 0.061). Populations in baris characterized by low SES are more likely to experience higher cholera morbidity at the beginning of an epidemic than populations in high

  14. A genome-wide approach to discovery of small RNAs involved in regulation of virulence in Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Evan S Bradley

    2011-07-01

    Full Text Available Small RNAs (sRNAs are becoming increasingly recognized as important regulators in bacteria. To investigate the contribution of sRNA mediated regulation to virulence in Vibrio cholerae, we performed high throughput sequencing of cDNA generated from sRNA transcripts isolated from a strain ectopically expressing ToxT, the major transcriptional regulator within the virulence gene regulon. We compared this data set with ToxT binding sites determined by pulldown and deep sequencing to identify sRNA promoters directly controlled by ToxT. Analysis of the resulting transcripts with ToxT binding sites in cis revealed two sRNAs within the Vibrio Pathogenicity Island. When deletions of these sRNAs were made and the resulting strains were competed against the parental strain in the infant mouse model of V. cholerae colonization, one, TarB, displayed a variable colonization phenotype dependent on its physiological state at the time of inoculation. We identified a target of TarB as the mRNA for the secreted colonization factor, TcpF. We verified negative regulation of TcpF expression by TarB and, using point mutations that disrupted interaction between TarB and tpcF mRNA, showed that loss of this negative regulation was primarily responsible for the colonization phenotype observed in the TarB deletion mutant.

  15. Serine 26 in the PomB subunit of the flagellar motor is essential for hypermotility of Vibrio cholerae.

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    Petra Halang

    Full Text Available Vibrio cholerae is motile by means of its single polar flagellum which is driven by the sodium-motive force. In the motor driving rotation of the flagellar filament, a stator complex consisting of subunits PomA and PomB converts the electrochemical sodium ion gradient into torque. Charged or polar residues within the membrane part of PomB could act as ligands for Na+, or stabilize a hydrogen bond network by interacting with water within the putative channel between PomA and PomB. By analyzing a large data set of individual tracks of swimming cells, we show that S26 located within the transmembrane helix of PomB is required to promote very fast swimming of V. cholerae. Loss of hypermotility was observed with the S26T variant of PomB at pH 7.0, but fast swimming was restored by decreasing the H+ concentration of the external medium. Our study identifies S26 as a second important residue besides D23 in the PomB channel. It is proposed that S26, together with D23 located in close proximity, is important to perturb the hydration shell of Na+ before its passage through a constriction within the stator channel.

  16. Cholera toxin B subunit acts as a potent systemic adjuvant for HIV-1 DNA vaccination intramuscularly in mice.

    Science.gov (United States)

    Hou, Jue; Liu, Ying; Hsi, Jenny; Wang, Hongzhi; Tao, Ran; Shao, Yiming

    2014-01-01

    Cholera toxin B subunit (CTB) was investigated as a classical mucosal adjuvant that can increase vaccine immunogenicity. In this study, we found out the in vitro efficacy of cholera toxin B subunit (CTB) in activating mice bone marrow-derived dendritic cells (BMDCs) through Toll-like receptor signaling pathways. In vitro RNA and transcriptional level profiling arrays revealed that CTB guides high levels of Th1 and Th2 type cytokines, inflammatory cytokines, and chemokines. Based on the robustness of these profiling results, we examined the induction of HIV Env-specific immunity by CTB co-inoculated with HIV Env DNA vaccine intramuscularly in vivo. CTB enhanced HIV-Env specific cellular immune responses in Env-specific IFN-γ ELISPOT, compared with DNA vaccine alone. Moreover, CTB induced high levels of Env specific humoral response and promoted antibody maturation after the third round of vaccination. This combination immunization strategy induced a Th2-type bias response which is indicative of a high ratio of IgG1/IgG2a. This study reports that CTB as a classical mucosal adjuvant could enhance HIV-1 DNA-based vaccine immunogenicity intramuscularly; therefore, these findings suggest that CTB could serve as an effective candidate adjuvant for DNA vaccination.

  17. Resveratrol--a potential inhibitor of biofilm formation in Vibrio cholerae.

    Science.gov (United States)

    Augustine, Nimmy; Goel, A K; Sivakumar, K C; Kumar, R Ajay; Thomas, Sabu

    2014-02-15

    Resveratrol, a phytochemical commonly found in the skin of grapes and berries, was tested for its biofilm inhibitory activity against Vibrio cholerae. Biofilm inhibition was assessed using crystal violet assay. MTT assay was performed to check the viability of the treated bacterial cells and the biofilm architecture was analysed using confocal laser scanning microscopy. The possible target of the compound was determined by docking analysis. Results showed that subinhibitory concentrations of the compound could significantly inhibit biofilm formation in V. cholerae in a concentration-dependent manner. AphB was found to be the putative target of resveratrol using docking analysis. The results generated in this study proved that resveratrol is a potent biofilm inhibitor of V. cholerae and can be used as a novel therapeutic agent against cholera. To our knowledge, this is the first report of resveratrol showing antibiofilm activity against V. cholerae.

  18. 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

    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...... into artificial seawater, bacterial aggregates continued to express tcpA for prolonged periods of time. The bistable control of virulence gene expression points to a mechanism that could generate a subpopulation of V. cholerae that continues to produce TCP and CT in the rice water stools of cholera patients....

  19. 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.

  20. A study on the geophylogeny of clinical and environmental Vibrio cholerae in Kenya.

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    John Kiiru

    Full Text Available Cholera remains a significant public health challenge in many sub-Saharan countries including Kenya. We have performed a combination of phylogenetic and phenotypic analysis based on whole genome DNA sequences derived from 40 environmental and 57 clinical V. cholerae from different regions of Kenya isolated between 2005 and 2010. Some environmental and all clinical isolates mapped back onto wave three of the monophyletic seventh pandemic V. cholerae El Tor phylogeny but other environmental isolates were phylogenetically very distinct. Thus, the genomes of the Kenyan V. cholerae O1 El Tor isolates are clonally related to other El Tor V. cholerae isolated elsewhere in the world and similarly harbour antibiotic resistance-associated STX elements. Further, the Kenyan O1 El Tor isolates fall into two distinct clades that may have entered Kenya independently.

  1. Improved laboratory capacity is required to respond better to future cholera outbreaks in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Paul Horwood

    2012-05-01

    Full Text Available Cholera was first detected in Papua New Guinea in July 2009, caused by Vibrio cholerae O1 El Tor serotype Ogawa. By late 2011, 15 500 cases had been reported throughout lowland Papua New Guinea with a case fatality rate of 3.2%. The epidemic has since slowed, with only sporadic cases reported in Western Province and the Autonomous Region of Bougainville (ARB. Accurate and timely diagnosis is a critical element of the public health response to cholera, yet in low-income countries where the burden of cholera is the greatest, diagnostic services are often limited. Here we report on the diagnostic challenges and the logistical factors that impacted on diagnosis during the first reported outbreak of cholera in Papua New Guinea.

  2. Prevalence and characterization of Vibrio cholerae isolated from shrimp products imported into Denmark

    DEFF Research Database (Denmark)

    Dalsgaard, A.; Bjergskov, T.; Jeppesen, V.F.

    1996-01-01

    A total of 3,555 metric tonnes of warm water shrimp were imported into Denmark from December 1994 to July 1995. V. cholerae O1 was not detected in any of the 748 samples analyzed. Non-Ol V. cholerae was found in a single (0.1%) cooked frozen shrimp product and in five (0.7%) raw frozen products...... contained plasmids or genes encoding cholera toxin (CT) or heat-stable enterotoxin (NAG-ST), The absence of V. cholerae O1 and the low number of samples containing CT and NAG-ST negative non-Ol strains in imported shrimp suggest that I! cholerae in such products may not constitute a public health problem....

  3. 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...... water fish may serve as a transmission vehicle of potential emerging epidemic causing strains. For this, we studied 9 toxigenic V. cholerae strains isolated from Hilsha fish including 6 V. cholerae O1 and 3 non O1/O139 serogroups for virulence associated genotype and their pathogenic potential on animal...... model and human cancer cell line . The V. cholerae O1 and non- O1/O139 strains possessed diverse virulence genes but lacked some major toxin genes like ctxA, tcp etc. Eight of the nine strains showed survivability up to 1% sodium chloride in broth culture which indicates their coastal origin. All nine...

  4. 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.

  5. High-Resolution Crystal Structures Elucidate the Molecular Basis of Cholera Blood Group Dependence.

    Science.gov (United States)

    Heggelund, Julie Elisabeth; Burschowsky, Daniel; Bjørnestad, Victoria Ariel; Hodnik, Vesna; Anderluh, Gregor; Krengel, Ute

    2016-04-01

    Cholera is the prime example of blood-group-dependent diseases, with individuals of blood group O experiencing the most severe symptoms. The cholera toxin is the main suspect to cause this relationship. We report the high-resolution crystal structures (1.1-1.6 Å) of the native cholera toxin B-pentamer for both classical and El Tor biotypes, in complexes with relevant blood group determinants and a fragment of its primary receptor, the GM1 ganglioside. The blood group A determinant binds in the opposite orientation compared to previously published structures of the cholera toxin, whereas the blood group H determinant, characteristic of blood group O, binds in both orientations. H-determinants bind with higher affinity than A-determinants, as shown by surface plasmon resonance. Together, these findings suggest why blood group O is a risk factor for severe cholera.

  6. A co-infection model of malaria and cholera diseases with optimal control.

    Science.gov (United States)

    Okosun, K O; Makinde, O D

    2014-12-01

    In this paper we formulate a mathematical model for malaria-cholera co-infection in order to investigate their synergistic relationship in the presence of treatments. We first analyze the single infection steady states, calculate the basic reproduction number and then investigate the existence and stability of equilibria. We then analyze the co-infection model, which is found to exhibit backward bifurcation. The impact of malaria and its treatment on the dynamics of cholera is further investigated. Secondly, we incorporate time dependent controls, using Pontryagin's Maximum Principle to derive necessary conditions for the optimal control of the disease. We found that malaria infection may be associated with an increased risk of cholera but however, cholera infection is not associated with an increased risk for malaria. Therefore, to effectively control malaria, the malaria intervention strategies by policy makers must at the same time also include cholera control.

  7. Predictors of disease severity in patients admitted to a cholera treatment center in urban Haiti.

    Science.gov (United States)

    Valcin, Claude-Lyne; Severe, Karine; Riche, Claudia T; Anglade, Benedict S; Moise, Colette Guiteau; Woodworth, Michael; Charles, Macarthur; Li, Zhongze; Joseph, Patrice; Pape, Jean W; Wright, Peter F

    2013-10-01

    Cholera, previously unrecognized in Haiti, spread through the country in the fall of 2010. An analysis was performed to understand the epidemiological characteristics, clinical management, and risk factors for disease severity in a population seen at the GHESKIO Cholera Treatment Center in Port-au-Prince. A comprehensive review of the medical records of patients admitted during the period of October 28, 2010-July 10, 2011 was conducted. Disease severity on admission was directly correlated with older age, more prolonged length of stay, and presentation during the two epidemic waves seen in the observation period. Although there was a high seroprevalence of human immunodeficiency virus (HIV), severity of cholera was not greater with HIV infection. This study documents the correlation of cholera waves with rainfall and its reduction in settings with improved sanitary conditions and potable water when newly introduced cholera affects all ages equally so that interventions must be directed throughout the population.

  8. Biochemical and full genome sequence analyses of clinical Vibrio cholerae isolates in Mexico reveals the presence of novel V. cholerae strains.

    Science.gov (United States)

    Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; Montes-Colima, Norma Angélica; Moreno-Pérez, María Asunción; Galicia-Nicolás, Adriana Guadalupe; López-Martínez, Irma; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ortíz-Alcántara, Joanna María; Garcés-Ayala, Fabiola; Ramírez-González, José Ernesto

    2016-05-01

    The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by PFGE and by PCR-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the four strains obtained in this study confirmed the presence of Pathogenicity Islands VPI-1 and -2, VSP-1 and -2, and of the integrative element SXT. The genomic structure of the 4 isolates was similar to that of V. cholerae strain 2010 EL-1786, identified during the epidemic in Haiti in 2010.

  9. Intranasal delivery of cholera toxin induces th17-dominated T-cell response to bystander antigens.

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    Jee-Boong Lee

    Full Text Available Cholera toxin (CT is a potent vaccine adjuvant, which promotes mucosal immunity to protein antigen given by nasal route. It has been suggested that CT promotes T helper type 2 (Th2 response and suppresses Th1 response. We here report the induction of Th17-dominated responses in mice by intranasal delivery of CT. This dramatic Th17-driving effect of CT, which was dependent on the B subunit, was observed even in Th1 or Th2-favored conditions of respiratory virus infection. These dominating Th17 responses resulted in the significant neutrophil accumulation in the lungs of mice given CT. Both in vitro and in vivo treatment of CT induced strongly augmented IL-6 production, and Th17-driving ability of CT was completely abolished in IL-6 knockout mice, indicating a role of this cytokine in the Th17-dominated T-cell responses by CT. These data demonstrate a novel Th17-driving activity of CT, and help understand the mechanisms of CT adjuvanticity to demarcate T helper responses.

  10. Nod2-mediated recognition of the microbiota is critical for mucosal adjuvant activity of cholera toxin

    Science.gov (United States)

    Kim, Donghyun; Kim, Yun-Gi; Seo, Sang-Uk; Kim, Dong-Jae; Kamada, Nobuhiko; Prescott, Dave; Philpott, Dana J.; Rosenstiel, Philip; Inohara, Naohiro; Núñez, Gabriel

    2016-01-01

    Cholera toxin (CT) is a potent adjuvant for inducing mucosal immune responses. However, the mechanism by which CT induces adjuvant activity remains unclear. Here we show that the microbiota is critical for inducing antigen-specific IgG production after intranasal immunization. After mucosal vaccination with CT, both antibiotic-treated mice and germ-free (GF) had reduced antigen-specific IgG, recall-stimulated cytokine responses, an impaired follicular helper T (TFH) response and reduced plasma cells. Recognition of symbiotic bacteria via Nod2 in CD11c+ cells was required for the adjuvanticity of CT. Reconstitution of GF mice with a Nod2 agonist or Staphylococcus sciuri having high Nod2-stimulatory activity was sufficient to promote robust CT adjuvant activity whereas bacteria with low Nod2-stimulatory activity did not. Mechanistically, CT enhanced Nod2-mediated cytokine production in DCs via intracellular cAMP. These results show an important role for the microbiota and the intracellular receptor Nod2 in promoting the mucosal adjuvant activity of CT. PMID:27064448

  11. Genotypic and PFGE/MLVA analyses of Vibrio cholerae O1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in Thailand.

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    Kazuhisa Okada

    Full Text Available BACKGROUND: Vibrio cholerae O1 El Tor dominated the seventh cholera pandemic which occurred in the 1960s. For two decades, variants of V. cholerae O1 El Tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic El Tor biotype. This study aims to characterize V. cholerae O1 isolates from outbreaks in Thailand with special reference to genotypic variations over time. METHODS/FINDINGS: A total of 343 isolates of V. cholerae O1 from cholera outbreaks from 2007 to 2010 were investigated, and 99.4% were found to carry the classical cholera toxin B subunit (ctxB and El Tor rstR genes. Pulsed-field gel electrophoresis (PFGE differentiated the isolates into 10 distinct pulsotypes, clustered into two major groups, A and B, with an overall similarity of 88%. Ribotyping, multiple-locus variable-number tandem-repeat analysis (MLVA, and PCR to detect Vibrio seventh pandemic island II (VSP-II related genes of randomly selected isolates from each pulsotype corresponded to the results obtained by PFGE. Epidemiological investigations revealed that MLVA type 2 was strongly associated with a cholera outbreak in northeastern Thailand in 2007, while MLVA type 7 dominated the outbreaks of the southern Gulf areas in 2009 and MLVA type 4 dominated the outbreaks of the central Gulf areas during 2009-2010. Only MLVA type 16 isolates were found in a Thai-Myanmar border area in 2010, whereas those of MLVA types 26, 39, and 41 predominated this border area in 2008. Type 39 then disappeared 1-2 years later as MLVA type 41 became prevalent. Type 41 was also found to infect an outbreak area. CONCLUSIONS: MLVA provided a high-throughput genetic typing tool for understanding the in-depth epidemiology of cholera outbreaks. Our epidemiological surveys suggest that some clones of V. cholerae O1 with similar but distinctive genetic traits circulate in outbreak sites, while others disappear over time.

  12. Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments

    OpenAIRE

    Madhusudana, Rao B.; Surendran, P. K.

    2011-01-01

    Water and post-larvae samples from black tiger (Penaeus monodon) shrimp hatcheries; pond water, pond sediment and shrimp from aquaculture farms were screened for the presence of V. cholerae. A V. cholerae-duplex PCR method was developed by utilizing V. cholerae species specific sodB primers and ctxAB genes specific primers. Incidence of V. cholerae was not observed in shrimp hatchery samples but was noticed in aquaculture samples. The incidence of V. cholerae was higher in pond water (7.6%) t...

  13. Spatio-temporal clustering of cholera: the impact of flood control in Matlab, Bangladesh, 1983-2003.

    Science.gov (United States)

    Carrel, Margaret; Emch, Michael; Streatfield, Peter K; Yunus, Mohammad

    2009-09-01

    Introducing flood control to an area of endemic waterborne diseases could have significant impacts on spatio-temporal occurrence of cholera. Using 21-year data from Bangladesh, we conducted cluster analysis to explore changes in spatial and temporal distribution of cholera incidence since the construction of flood control structures. Striking changes in temporal cluster patterns emerged, including a shift from dry-season to rainy-season clusters following flood protection and delayed clustering inside the protected areas. Spatial differences in pre-flood protection and post-protection cholera clusters are weaker. Changes in spatio-temporal cholera clustering, associated with implementation of flood protection strategies, could affect local cholera prevention efforts.

  14. Development and evaluation of an enzyme-labeled antibody test for the rapid detection of hog cholera antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, G.C.

    1977-01-01

    A rapid enzyme-labeled antibody (ELA) microtechnique for the screening of swine for hog cholera antibodies was developed and evaluated with a blind study, using a 640-sample hog cholera serum bank. The total time to run a group of 22 samples was approximately 1 hour. The ELA test results correlated >99% with hog cholera serum-neutralization test results on the same serums. Test results also indicated that the ELA test shares with the hog cholera serum-neutralization test the problem of cross reactions between the antibodies of hog cholera and bovine viral diarrhea.

  15. Molecular insights into the evolutionary pathway of Vibrio cholerae O1 atypical El Tor variants.

    Science.gov (United States)

    Kim, Eun Jin; Lee, Dokyung; Moon, Se Hoon; Lee, Chan Hee; Kim, Sang Jun; Lee, Jae Hyun; Kim, Jae Ouk; Song, Manki; Das, Bhabatosh; Clemens, John D; Pape, Jean William; Nair, G Balakrish; Kim, Dong Wook

    2014-09-01

    Pandemic V. cholerae strains in the O1 serogroup have 2 biotypes: classical and El Tor. The classical biotype strains of the sixth pandemic, which encode the classical type cholera toxin (CT), have been replaced by El Tor biotype strains of the seventh pandemic. The prototype El Tor strains that produce biotype-specific cholera toxin are being replaced by atypical El Tor variants that harbor classical cholera toxin. Atypical El Tor strains are categorized into 2 groups, Wave 2 and Wave 3 strains, based on genomic variations and the CTX phage that they harbor. Whole-genome analysis of V. cholerae strains in the seventh cholera pandemic has demonstrated gradual changes in the genome of prototype and atypical El Tor strains, indicating that atypical strains arose from the prototype strains by replacing the CTX phages. We examined the molecular mechanisms that effected the emergence of El Tor strains with classical cholera toxin-carrying phage. We isolated an intermediary V. cholerae strain that carried two different CTX phages that encode El Tor and classical cholera toxin, respectively. We show here that the intermediary strain can be converted into various Wave 2 strains and can act as the source of the novel mosaic CTX phages. These results imply that the Wave 2 and Wave 3 strains may have been generated from such intermediary strains in nature. Prototype El Tor strains can become Wave 3 strains by excision of CTX-1 and re-equipping with the new CTX phages. Our data suggest that inter-chromosomal recombination between 2 types of CTX phages is possible when a host bacterial cell is infected by multiple CTX phages. Our study also provides molecular insights into population changes in V. cholerae in the absence of significant changes to the genome but by replacement of the CTX prophage that they harbor.

  16. Members of the human gut microbiota involved in recovery from Vibrio cholerae infection.

    Science.gov (United States)

    Hsiao, Ansel; Ahmed, A M Shamsir; Subramanian, Sathish; Griffin, Nicholas W; Drewry, Lisa L; Petri, William A; Haque, Rashidul; Ahmed, Tahmeed; Gordon, Jeffrey I

    2014-11-20

    Given the global burden of diarrhoeal diseases, it is important to understand how members of the gut microbiota affect the risk for, course of, and recovery from disease in children and adults. The acute, voluminous diarrhoea caused by Vibrio cholerae represents a dramatic example of enteropathogen invasion and gut microbial community disruption. Here we conduct a detailed time-series metagenomic study of faecal microbiota collected during the acute diarrhoeal and recovery phases of cholera in a cohort of Bangladeshi adults living in an area with a high burden of disease. We find that recovery is characterized by a pattern of accumulation of bacterial taxa that shows similarities to the pattern of assembly/maturation of the gut microbiota in healthy Bangladeshi children. To define the underlying mechanisms, we introduce into gnotobiotic mice an artificial community composed of human gut bacterial species that directly correlate with recovery from cholera in adults and are indicative of normal microbiota maturation in healthy Bangladeshi children. One of the species, Ruminococcus obeum, exhibits consistent increases in its relative abundance upon V. cholerae infection of the mice. Follow-up analyses, including mono- and co-colonization studies, establish that R. obeum restricts V. cholerae colonization, that R. obeum luxS (autoinducer-2 (AI-2) synthase) expression and AI-2 production increase significantly with V. cholerae invasion, and that R. obeum AI-2 causes quorum-sensing-mediated repression of several V. cholerae colonization factors. Co-colonization with V. cholerae mutants discloses that R. obeum AI-2 reduces Vibrio colonization/pathogenicity through a novel pathway that does not depend on the V. cholerae AI-2 sensor, LuxP. The approach described can be used to mine the gut microbiota of Bangladeshi or other populations for members that use autoinducers and/or other mechanisms to limit colonization with V. cholerae, or conceivably other enteropathogens.

  17. Human Mobility Patterns and Cholera Epidemics: a Spatially Explicit Modeling Approach

    Science.gov (United States)

    Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2010-12-01

    Cholera is an acute enteric disease caused by the ingestion of water or food contaminated by the bacterium Vibrio cholerae. Although most infected individuals do not develop severe symptoms, their stool may contain huge quantities of V.~cholerae cells. Therefore, while traveling or commuting, asymptomatic carriers can be responsible for the long-range dissemination of the disease. As a consequence, human mobility is an alternative and efficient driver for the spread of cholera, whose primary propagation pathway is hydrological transport through river networks. We present a multi-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of V.~cholerae due to human movement. In particular, building on top of state-of-the-art spatially explicit models for cholera spread through surface waters, we describe human movement and its effects on the propagation of the disease by means of a gravity-model approach borrowed from transportation theory. Gravity-like contact processes have been widely used in epidemiology, because they can satisfactorily depict human movement when data on actual mobility patterns are not available. We test our model against epidemiological data recorded during the cholera outbreak occurred in the KwaZulu-Natal province of South Africa during years 2000--2001. We show that human mobility does actually play an important role in the formation of the spatiotemporal patterns of cholera epidemics. In particular, long-range human movement may determine inter-catchment dissemination of V.~cholerae cells, thus in turn explaining the emergence of epidemic patterns that cannot be produced by hydrological transport alone. We also show that particular attention has to be devoted to study how heterogeneously distributed drinking water supplies and sanitation conditions may affect cholera transmission.

  18. Biological characterization of v. Cholerae-specific bacteriophages isolated from water sources in Georgia.

    Science.gov (United States)

    Elbakidze, T; Kokashvili, T; Janelidze, N; Porchkhidze, K; Koberidze, T; Tediashvili, M

    2015-03-01

    Vibrio cholerae, a widely spread bacterium in various marine, fresh, and brackish water environments, can cause a devastating diarrheal disease - cholera and also mild forms of gastroenteritis. Bacterial viruses are natural controllers of bacterial population density in water systems. The goal of this study was to isolate and characterize V. cholerae-specific bacteriophages occurring in the Georgian coastal zone of the Black Sea and inland water reservoirs in the eastern part of Georgia. During 2006-2009, 71 phages lytic to V. cholerae were collected from these aquatic environments. The phage isolation rate was varying from 8% to 15%, depending on the sampling season and site, and the abundance of host bacteria. The majority of phages specific to V. cholerae were collected from freshwater sources. The phage isolation showed seasonal character covering warm period -from April to September. Based on basic characteristics of primary phage isolates (lytic spectrum, virion morphology and DNA restriction profiles) 23 V. cholerae -specific phages were selected for series of consecutive screenings. Comparatively wide spectrum of lytic activity was revealed in case of 14 phages specific to V. cholerae O1, and one phage - VchBS3, active against non-O1 V. cholerae. Three phages active against V. cholerae non-O1 and six V. cholerae O1 -specific phages have been studied in detail for a number of biological features (stability in different solutions, temperature-, pH- and UV- sensitivity, influence of high ionic strength etc.), considered to be additional important characteristics for selection of phages with therapeutic potential.

  19. Climate and infectious disease: use of remote sensing for detection of Vibrio cholerae by indirect measurement

    Science.gov (United States)

    Lobitz, B.; Beck, L.; Huq, A.; Wood, B.; Fuchs, G.; Faruque, A. S.; Colwell, R.

    2000-01-01

    It has long been known that cholera outbreaks can be initiated when Vibrio cholerae, the bacterium that causes cholera, is present in drinking water in sufficient numbers to constitute an infective dose, if ingested by humans. Outbreaks associated with drinking or bathing in unpurified river or brackish water may directly or indirectly depend on such conditions as water temperature, nutrient concentration, and plankton production that may be favorable for growth and reproduction of the bacterium. Although these environmental parameters have routinely been measured by using water samples collected aboard research ships, the available data sets are sparse and infrequent. Furthermore, shipboard data acquisition is both expensive and time-consuming. Interpolation to regional scales can also be problematic. Although the bacterium, V. cholerae, cannot be sensed directly, remotely sensed data can be used to infer its presence. In the study reported here, satellite data were used to monitor the timing and spread of cholera. Public domain remote sensing data for the Bay of Bengal were compared directly with cholera case data collected in Bangladesh from 1992-1995. The remote sensing data included sea surface temperature and sea surface height. It was discovered that sea surface temperature shows an annual cycle similar to the cholera case data. Sea surface height may be an indicator of incursion of plankton-laden water inland, e.g., tidal rivers, because it was also found to be correlated with cholera outbreaks. The extensive studies accomplished during the past 25 years, confirming the hypothesis that V. cholerae is autochthonous to the aquatic environment and is a commensal of zooplankton, i.e., copepods, when combined with the findings of the satellite data analyses, provide strong evidence that cholera epidemics are climate-linked.

  20. Integrating Terrestrial Hydrology and Coastal Ecology: Understanding Cholera Dynamics using Remote Sensing Data

    Science.gov (United States)

    Islam, S.; Jutla, A. S.; Akanda, A. S.

    2009-12-01

    Cholera, an acute water-borne diarrheal illness, remains endemic in many regions of the world, specifically the coastal regions of South Asia, Sub-Saharan Africa, and Latin America. The disease has reemerged as a global killer with the world witnessing an unprecedented rise in cholera infection and transmission since the 1990s. In addition, global warming and natural disasters can contribute to outbreaks or occurrences of cholera in places where they normally do not pose a problem, including the US coastal areas. This study investigates relationship(s) between cholera incidences, coastal processes and terrestrial hydrology and explores the utility of using remote sensing data to track coastal plankton blooms and subsequent cholera outbreaks in vulnerable regions. Most of the studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks, however, successful identification and mechanistic understanding of large scale hydrological, geophysical and coastal processes governing plankton-cholera relationships is important for developing any predictive model for disease outbreaks. The impact of climate change induced sea level rise on aquatic ecosystems and the altered spatial signature of coastal salinity distribution is likely to have significant impact on the composition of the plankton community and the production and growth of the cholera bacteria. Development of a holistic understanding of these processes requires long and reliable chlorophyll dataset, a surrogate for plankton abundance, which is now available through satellites. We will present a plausible pathway relating cholera, sea surface temperature, chlorophyll, and terrestrial hydrology through river discharge and satellite estimated coastal plankton abundance. Remote sensing, with its unprecedented spatial and temporal coverage, has capabilities to monitor coastal processes and track potential cholera outbreaks in endemic regions.

  1. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

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    Didier Bompangue

    Full Text Available BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants and South Kivu (4,670,121 inhabitants from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9. Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  2. Historical report: first isolation of Vibrio Cholera serogroup 01 biovar El Tor serovar inaba during the cholerae epidemic in Peru - 1991

    OpenAIRE

    Bravo Cruz, Nora; Facultad de Ciencias Naturales y Matemática, Universidad Nacional Federico Villarreal. Bióloga. Exjefa del Departamento de Bacteriología, Centro Nacional de Salud Pública, Instituto Nacional de Salud.; Guillén, Alfredo; Facultad de Tecnología Médica, Universidad Nacional Federico Villarreal. Clínica San Borja. Médico Microbiólogo.

    2011-01-01

    20 years ago, a new diarrheal disease was introduced in Peru and the Enteropathogens Reference Laboratory of the Instituto Nacional de Salud had an outstanding role in the isolation and rapid and timely identification of Vibrio cholerae. Cholera had not been seen before, but during the last week of January 1991 an outbreak of acute diarrhea was detected, presenting intense dehydration and some deaths. The epidemic affected, in the beginning, many locations of the peruvian coast. Some work...

  3. Evidence of a dominant lineage of Vibrio cholerae-specific lytic bacteriophages shed by cholera patients over a 10-year period in Dhaka, Bangladesh.

    Science.gov (United States)

    Seed, Kimberley D; Bodi, Kip L; Kropinski, Andrew M; Ackermann, Hans-Wolfgang; Calderwood, Stephen B; Qadri, Firdausi; Camilli, Andrew

    2011-01-01

    Lytic bacteriophages are hypothesized to contribute to the seasonality and duration of cholera epidemics in Bangladesh. However, the bacteriophages contributing to this phenomenon have yet to be characterized at a molecular genetic level. In this study, we isolated and sequenced the genomes of 15 bacteriophages from stool samples from cholera patients spanning a 10-year surveillance period in Dhaka, Bangladesh. Our results indicate that a single novel bacteriophage type, designated ICP1 (for the International Centre for Diarrhoeal Disease Research, Bangladesh cholera phage 1) is present in all stool samples from cholera patients, while two other bacteriophage types, one novel (ICP2) and one T7-like (ICP3), are transient. ICP1 is a member of the Myoviridae family and has a 126-kilobase genome comprising 230 open reading frames. Comparative sequence analysis of ICP1 and related isolates from this time period indicates a high level of genetic conservation. The ubiquitous presence of ICP1 in cholera patients and the finding that the O1 antigen of lipopolysaccharide (LPS) serves as the ICP1 receptor suggest that ICP1 is extremely well adapted to predation of human-pathogenic V. cholerae O1.

  4. Inhibition of the sodium-translocating NADH-ubiquinone oxidoreductase [Na+-NQR] decreases cholera toxin production in Vibrio cholerae O1 at the late exponential growth phase.

    Science.gov (United States)

    Minato, Yusuke; Fassio, Sara R; Reddekopp, Rylan L; Häse, Claudia C

    2014-01-01

    Two virulence factors produced by Vibrio cholerae, cholera toxin (CT) and toxin-corregulated pilus (TCP), are indispensable for cholera infection. ToxT is the central regulatory protein involved in activation of CT and TCP expression. We previously reported that lack of a respiration-linked sodium-translocating NADH-ubiquinone oxidoreductase (Na(+)-NQR) significantly increases toxT transcription. In this study, we further characterized this link and found that Na(+)-NQR affects toxT expression only at the early-log growth phase, whereas lack of Na(+)-NQR decreases CT production after the mid-log growth phase. Such decreased CT production was independent of toxT and ctxB transcription. Supplementing a respiratory substrate, l-lactate, into the growth media restored CT production in the nqrA-F mutant, suggesting that decreased CT production in the Na(+)-NQR mutant is dependent on electron transport chain (ETC) activity. This notion was supported by the observations that two chemical inhibitors, a Na(+)-NQR specific inhibitor 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO) and a succinate dehydrogenase (SDH) inhibitor, thenoyltrifluoroacetone (TTFA), strongly inhibited CT production in both classical and El Tor biotype strains of V. cholerae. Accordingly, we propose the main respiratory enzyme of V. cholerae, as a potential drug target to treat cholera because human mitochondria do not contain Na(+)-NQR orthologs.

  5. Environmental determinants of cholera outbreaks in inland Africa: a systematic review of main transmission foci and propagation routes.

    Science.gov (United States)

    Rebaudet, Stanislas; Sudre, Bertrand; Faucher, Benoît; Piarroux, Renaud

    2013-11-01

    Cholera is generally regarded as the prototypical waterborne and environmental disease. In Africa, available studies are scarce, and the relevance of this disease paradigm is questionable. Cholera outbreaks have been repeatedly reported far from the coasts: from 2009 through 2011, three-quarters of all cholera cases in Africa occurred in inland regions. Such outbreaks are either influenced by rainfall and subsequent floods or by drought- and water-induced stress. Their concurrence with global climatic events has also been observed. In lakes and rivers, aquatic reservoirs of Vibrio cholerae have been evocated. However, the role of these reservoirs in cholera epidemiology has not been established. Starting from inland cholera-endemic areas, epidemics burst and spread to various environments, including crowded slums and refugee camps. Human displacements constitute a major determinant of this spread. Further studies are urgently needed to better understand these complex dynamics, improve water and sanitation efforts, and eliminate cholera from Africa.

  6. [DETERMINATION OF TYPES OF EPIDEMIC MANIFESTATIONS OF CHOLERA IN REGIONS OF THE CRIMEA FEDERAL DISTRICT (REPUBLIC OF CRIMEA)].

    Science.gov (United States)

    Onischenko, G G; Popova, A Yu; Moskvitina, E A; Penkovskaya, N A; Listopad, S A; Titova, S V; Kruglikov, V D

    2015-01-01

    The aim of the study was determination of the type of epidemic manifestations of cholera in the Republic of Crimea based on evaluation of epidemic manifestations of cholera risk of introduction and spread of the infection. It was concluded, that, based on the cholera outbreaks, that had taken place, contamination of surface water bodies (fresh and sea) and sewage by Vibrio cholerae O1 ctxA+ and Vibrio cholerae O1 ctXA- potential epidemic danger of introduction of the infection by various types of international transport, population migration, the presence of epidemiologic risk in realization of water pathway of transmission of cholera causative agent and several other social conditions, the Republic of Crimea remains in the group of territories of type I by epidemic manifestations of cholera.

  7. Twin outbreak of cholera in rural North Karnataka, India

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    Shuchismita Dey

    2014-01-01

    Full Text Available Background & objectives: Successive outbreaks of acute watery diarrhoea occurred in Talikoti and Harnal, located in Bijapur District of the southern Indian s0 tate of Karnataka, in July and August 2012, respectively. These outbreaks were investigated to identify the aetiology and epidemiology. Methods: Information was collected from the local population and health centres. Stool and water samples were collected from the admitted patients and their drinking water sources. Standard microbiological and PCR techniques were employed for isolation and characterization of the pathogen. Results: While 101 people (0.38% were affected in Talikoti, 200 (20.94% were affected in Harnal which is a small remote village. All age groups were affected but no death occurred. While the outbreak was smaller, longer and apparently spread by person to person contact in Talikoti, it occurred as a single source flash outbreak at Harnal. A single clone of toxigenic Vibrio cholerae O1 Ogawa biotype El Tor was isolated from the two stool samples obtained from Talikoti and subsequently from three of five stool samples obtained from Harnal indicating village to village spread of the aetiological agent. Striking similarity in antibiotic resistance profiles of these isolates with a particular strain isolated from the city of Belgaum, 250 km away, in 2010, prompted tracking the lineage of the V. cholerae isolates by DNA fingerprinting. Random amplified polymorphic DNA (RAPD fingerprinting assay helped confirm the origin of the incriminating strain to Belgaum. Interpretation & conclusions: Our study reported the first twin outbreak of cholera in two remote areas of Bijapur district, Karnataka, south India. It also indicated the need for immediate preparedness to deal with such emergencies.

  8. Mechanistic Insights Into Filamentous Phage Integration In Vibrio cholerae

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    Bhabatosh eDas

    2014-11-01

    Full Text Available Vibrio cholerae, the etiological agent of acute diarrhoeal disease cholera, harbors large numbers of lysogenic filamentous phages, contribute significantly to the host pathogenesis and provide fitness factors to the pathogen that help the bacterium to survive in natural environment. Most of the vibriophage genomes are not equipped with integrase and thus exploit two host-encoded tyrosine recombinases, XerC and XerD, for lysogenic conversion. Integration is site-specific and it occurs at dimer resolution site (dif of either one or both chromosomes of V. cholerae. Each dif sequence contains two recombinase-binding sequences flanking a central region. The integration follows a sequential strand exchanges between dif and attP sites within a DNA-protein complex consisting of one pair of each recombinase and two DNA fragments. During entire process of recombination, both the DNA components and recombinases of the synaptic complex keep transiently interconnected. Within the context of synaptic complex, both of the actuated enzymes mediate cleavage of phosphodiester bonds. First cleavage generates a phosphotyrosyl-linked recombinase-DNA complex at the recombinase binding sequence and free 5’-hydroxyl end at the first base of the central region. Following the cleavage, the exposed bases with 5’-hydroxyl ends of the central region of dif and attP sites melt from their complementary strands and react with the recombinase-DNA phosphotyrosyl linkage of their recombining partner. Subsequent ligation between dif and attP strands requires complementary base pair interactions at the site of phosphodiester bond formation. Integration mechanism is mostly influenced by the compatibility of dif and attP sequences. dif sites are highly conserved across bacterial phyla. Different phage genomes have different attP sequences; therefore they rely on different mechanisms for integration. Here, I review our current understanding of integration mechanisms used by the

  9. Studies of cholera El Tor in the Philippines*

    Science.gov (United States)

    Joseph, P. R.; Tamayo, J. F.; Mosley, W. H.; Alvero, M. G.; Dizon, J. J.; Henderson, D. A.

    1965-01-01

    The introduction of cholera into many of the islands of the Philippines in 1961 often occurred in an explosive manner. The disease was introduced into Bacolod City and Talisay in Negros Occidental Province in such a manner in November 1961. The authors describe the results of an analysis of hospital and health department records in Bacolod City and Talisay and the results of interviews conducted with adult patients 10 months after the explosive outbreak. The results suggest that infection during the initial explosive wave of cases in Bacolod City and Talisay in November 1961 was transmitted principally by shrimp that were consumed raw. PMID:5295144

  10. Supervivencia del Vibrio cholerae y V. parahaemolyticus en el ceviche

    OpenAIRE

    Alvarado Marenco, Priscilla; García Cortés, Vera

    1994-01-01

    Se estudió la supervivencia de Vibrio cholerae y V. parahaemolyticus, en ceviche preparado con una formulación estandarizada en Costa Rica. Se inoculó el pescado troceado para obtener cargas aproximadas, de cada microorganismo por separado, de 103 y 106 UFC/g en el ceviche preparado. Las pruebas se realizaron en ceviche elaborado a partir del pescado contaminado e incubado a 4°C hasta su análisis. Las muestras se tomaron al tiempo cero y a diferentes intervalos, hasta por 24 h. En general,...

  11. [The 1853-1856 cholera epidemic in the Portuguese press].

    Science.gov (United States)

    Almeida, Maria Antónia Pires de

    2011-12-01

    The article examines science and technology communication aimed at a non-specialized audience, using the general press as the main source in this endeavor to capture an image of the popularization of science in Portugal. Based on the fact that the nineteenth-century press was overtly concerned with garnering an audience and spreading knowledge, the study uses news, articles, and advertisements about the 1853-1856 cholera epidemic to assess the era's scientific knowledge (especially about prevention and treatment) and how this information was conveyed to society and used by it.

  12. The three-dimensional crystal structure of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)

    1996-02-01

    The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.

  13. Chlorination of Household Drinking Water Among Cholera Patients' Households to Prevent Transmission of Toxigenic Vibrio cholerae in Dhaka, Bangladesh: CHoBI7 Trial.

    Science.gov (United States)

    Rashid, Mahamud-Ur; George, Christine Marie; Monira, Shirajum; Mahmud, Toslim; Rahman, Zillur; Mustafiz, Munshi; Saif-Ur-Rahman, K M; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Biswas, Shwapon Kumar; Akhter, Shamima; Zhang, Xiaotong; Sack, David; Sack, R Bradley; Alam, Munirul

    2016-12-07

    Household members of cholera patients are at a 100 times higher risk of cholera infections than the general population because of shared contaminated drinking water sources and secondary transmission through poor household hygiene practices. In this study, we investigated the bactericidal concentration of free chlorine required to inactivate Vibrio cholerae in household drinking water in Dhaka, Bangladesh. In laboratory experiments, we found that the concentrations of free chlorine required to inactivate 10(5) colony-forming units (CFU)/mL of V. cholerae serogroups O1 and O139 were 0.1 mg/L and 0.2 mg/L, respectively. The concentration of free chlorine generated by a single chlorine tablet (sodium dichloroisocyanurate [33 mg]) after a 30-minute reaction time in a 10-L sealed vessel containing Dhaka city municipal supply water was 1.8 mg/L; and the concentration declined to 0.26 mg/L after 24 hours. In field measurements, water collected from 165 households enrolled in a randomized controlled trial (RCT) of a chlorine and handwashing with soap intervention (Cholera-Hospital-Based-Intervention-for-7-Days [CHoBI7]), we observed significantly higher free chlorine concentrations in the 82 intervention arm households (mean = 1.12 mg/L, standard deviation [SD] = 0.52, range = 0.07-2.6 mg/L) compared with the 83 control households (0.017 mg/L, SD = 0.01, range = 0-0.06 mg/L) (P < 0.001) during spot check visits. These findings suggest that point-of-use chlorine tablets present an effective approach to inactivate V. cholerae from drinking water in households of cholera patients in Dhaka city. This result is consistent with the findings from the RCT of CHoBI7 which found that this intervention led to a significant reduction in symptomatic cholera infections among household members of cholera patients and no stored drinking water samples with detectable V. cholerae.

  14. Characterization of Vibrio cholerae from 1986 to 2012 in Yunnan Province, southwest China bordering Myanmar.

    Science.gov (United States)

    Gu, Wenpeng; Yin, Jianwen; Yang, Jianbin; Li, Chaoqun; Chen, Yujuan; Yin, Jie; Xu, Wen; Zhao, Shiwen; Liang, Junrong; Jing, Huaiqi; Fu, Xiaoqing

    2014-01-01

    Vibrio cholerae is an important infectious pathogen causing serious human diarrhea. We analyzed 568 V. cholerae strains isolated from 1986 to 2012 in Yunnan province, southwest China bordering Myanmar. Polymerase chain reactions for detecting virulence genes, antibiotic susceptibility tests and pulse-field gel electrophoresis (PFGE) were performed. The results showed all the strains were El Tor biotype from 1986. The ctxB subunit sequence analysis for all strains have shown that cholera between 1986 and 1995 was associated with mixed infections with El Tor and El Tor variants, while infections after 1996 were all caused by El Tor variant strains. All of the strains were sensitive to aminoglycosides and quinolone antibiotics while resistant to β-lactamase and carbapenem antibiotics increased gradually. 568 V. cholerae were divided into 218 PFGE-NotI patterns, and the isolates before 2001 and after 2011 were separated into two groups according to PFGE results. The strains isolated before 2001 were mainly referred to native cholera in Yunnan, and after 2011 were primarily referred to as imported strains from Myanmar, which showed the variation of V. cholerae in this area. The molecular characteristics of V. cholerae indicated regularity in bacterial variation and evolution in Yunnan province.

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

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    Kevin eEsteves

    2015-07-01

    Full Text Available Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species can induce infections in humans. Therefore understanding the structure and dynamics of non-pandemic environmental populations in temperate regions, such as Mediterranean coastal systems, is important if we are to evaluate the risks of infection to 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 conditions for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity. 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.

  16. 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.

  17. Changing patterns of Vibrio cholerae in sevagram between 1990 and 2005

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    Narang P

    2008-01-01

    Full Text Available Purpose: A retrospective analysis was done to note changes in prevalence, distribution of biotypes, serotypes, antibiotic susceptibility patterns and phage types of Vibrio cholerae isolated in Mahatma Gandhi Institute of Medical Sciences, Sevagram over a period of 16 years. Methods: A total of 535 strains of V. cholerae were isolated from 10,406 stool samples and rectal swabs from January 1990 to December 2005. These comprised of serogroups O1 - 427 (79.89%, O139 - 86 (16.07% and non O1, non O139 - 22 (4.11%. No classical V. cholerae was isolated. Results: Vibrio cholerae serogroup O1 serotype Ogawa was the predominant isolate till 1992. During 1993, serogroup O139 became the main isolate; however, it completely disappeared during 1995-1996 only to reappear in 1997. Serotype Inaba in our area was conspicuous by its absence with only two strains being isolated till June 1999, but during July-December 1999, 11 out of 15 V. cholerae O1 isolates were El Tor Inaba. T4 was the predominant phage type till 1990, T2 during 1991-1994 and T27 (as per the new scheme thereafter. Resistance to tetracycline varied between 2 and 17% for V. cholerae O1. Conclusions: The paper reports on the changing epidemiological markers of V. cholerae isolated from a rural hospital over a period of 16 years.

  18. An Ecosocial Approach to the Epidemic of Cholera in the Marshall Islands

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    Wesley Palmer

    2007-04-01

    Full Text Available Abstract: A cholera outbreak occurred in the Marshall Islands in December 2000 to January 2001 with over 400 cases and six deaths. Within Kwajalein Atoll, cholera occurred on Ebeye Island, while it did not occur on Kwajalein Island, three miles away. We apply Krieger’s ecosocial approach in order to explicate the reasons for this dichotomy. We first examine how Marshallese people came to embody cholera as a disease state. Secondly, we examine the (a arrangements of power, property, production, and consumption in the Ebeye-Kwajalein complex, as well as (b human biology as it has been shaped by the ecological context in order to elucidate the pathways to the embodiment of cholera. Thirdly, we examine the cumulative interplay between exposure to cholera, as well as susceptibility and resistance to the disease at the level of individuals and the island-wide level. Fourthly, we examine who is responsible for the cholera outbreak and who describes the phenomena. We conclude that the outbreak of cholera in the Marshall Islands can be considered the biologic embodiment of disparate political and economic conditions and ecological imbalance. We suggest courses of action for those interested in addressing the inequalities and working towards health.

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

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    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.

  20. Hyperinfectivity: a critical element in the ability of V. cholerae to cause epidemics?

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    David M Hartley

    2006-01-01

    Full Text Available Cholera is an ancient disease that continues to cause epidemic and pandemic disease despite ongoing efforts to limit its spread. Mathematical models provide one means of assessing the utility of various proposed interventions. However, cholera models that have been developed to date have had limitations, suggesting that there are basic elements of cholera transmission that we still do not understand.Recent laboratory findings suggest that passage of Vibrio cholerae O1 Inaba El Tor through the gastrointestinal tract results in a short-lived, hyperinfectious state of the organism that decays in a matter of hours into a state of lower infectiousness. Incorporation of this hyperinfectious state into our disease model provides a much better fit with the observed epidemic pattern of cholera. These findings help to substantiate the clinical relevance of laboratory observations regarding the hyperinfectious state, and underscore the critical importance of human-to-human versus environment-to-human transmission in the generation of epidemic and pandemic disease.To have maximal impact on limiting epidemic spread of cholera, interventions should be targeted toward minimizing risk of transmission of the short-lived, hyperinfectious form of toxigenic Vibrio cholerae. The possibility of comparable hyperinfectious states in other major epidemic diseases also needs to be evaluated and, as appropriate, incorporated into models of disease prevention.

  1. Historical epidemiology of the second cholera pandemic: relevance to present day disease dynamics.

    Science.gov (United States)

    Chan, Christina H; Tuite, Ashleigh R; Fisman, David N

    2013-01-01

    Despite nearly two centuries of study, the fundamental transmission dynamic properties of cholera remain incompletely characterized. We used historical time-series data on the spread of cholera in twelve European and North American cities during the second cholera pandemic, as reported in Amariah Brigham's 1832 A Treatise on Epidemic Cholera, to parameterize simple mathematical models of cholera transmission. Richards growth models were used to derive estimates of the basic reproductive number (R0) (median: 16.0, range: 1.9 to 550.9) and the proportion of unrecognized cases (mean: 96.3%, SD: 0.04%). Heterogeneity in model-generated R0 estimates was consistent with variability in cholera dynamics described by contemporary investigators and may represent differences in the nature of cholera spread. While subject to limitations associated with measurement and the absence of microbiological diagnosis, historical epidemic data are a potentially rich source for understanding pathogen dynamics in the absence of control measures, particularly when used in conjunction with simple and readily interpretable mathematical models.

  2. Historical epidemiology of the second cholera pandemic: relevance to present day disease dynamics.

    Directory of Open Access Journals (Sweden)

    Christina H Chan

    Full Text Available Despite nearly two centuries of study, the fundamental transmission dynamic properties of cholera remain incompletely characterized. We used historical time-series data on the spread of cholera in twelve European and North American cities during the second cholera pandemic, as reported in Amariah Brigham's 1832 A Treatise on Epidemic Cholera, to parameterize simple mathematical models of cholera transmission. Richards growth models were used to derive estimates of the basic reproductive number (R0 (median: 16.0, range: 1.9 to 550.9 and the proportion of unrecognized cases (mean: 96.3%, SD: 0.04%. Heterogeneity in model-generated R0 estimates was consistent with variability in cholera dynamics described by contemporary investigators and may represent differences in the nature of cholera spread. While subject to limitations associated with measurement and the absence of microbiological diagnosis, historical epidemic data are a potentially rich source for understanding pathogen dynamics in the absence of control measures, particularly when used in conjunction with simple and readily interpretable mathematical models.

  3. Cholera epidemic associated with raw vegetables--Lusaka, Zambia, 2003-2004.

    Science.gov (United States)

    2004-09-03

    Zambia experienced widespread cholera epidemics in 1991 (13,154 cases), 1992 (11,659), and 1999 (11,327). In response to the large outbreak in 1999, the Zambian Ministry of Health (ZMOH) urged use of in-home chlorination with the locally produced solution, Clorin, and the practice increased substantially Clorin had been introduced in Zambia in 1998 as part of the Safe Water System (SWS), a point-of-use water disinfection and safe-water storage strategy launched by the Society for Family Health, in partnership with ZMOH, the U.S. Agency for International Development, and CDC. Although no outbreaks were reported during 2000-2002, cholera remained endemic. Epidemic cholera returned to Zambia in November 2003, when cases of toxigenic Vibrio cholerae O1, serotype Ogawa, biotype El Tor were confirmed in the capital city, Lusaka. During November 28, 2003-January 4, 2004, an estimated 2,529 cholera cases and 128 cholera deaths (case-fatality rate [CFR] = 5.1%) occurred in Lusaka. In February 2004, the Lusaka District Health Management Team (LDHMT) invited CDC to assist in an investigation of the epidemic. This report summarizes the results of that investigation, which implicated foodborne transmission via raw vegetables and demonstrated a protective role for hand washing with soap. The results underscore the importance of hygiene, clean water, and sanitary food handling for cholera prevention.

  4. A five-year study on the epidemiological approaches to cholera in Iran

    Science.gov (United States)

    Mafi, Moharam; Goya, Mohammad Mahdi; Hajia, Massoud

    2016-01-01

    Background: Cholera is considered a key indicator of social development but still is reported in various cities of Iran. The present study aimed to analyze the available information regarding cholera outbreaks since 2010 in Iran. Methods: All cases reported to the Center for Disease Control and Prevention of Ministry of Health and Education who had been confirmed as cholera cases by the Health Reference Laboratory, were entered into this study since 2010. A specific spreadsheet was designed to ensure the safe keeping of the patient records. Results: A total of 1522 patients were clinically diagnosed as cholera with laboratory confirmation over the study period. Cholera was detected in 26 Provinces and 115 cities during this period. Mean age of the patients was 35.1±17, both the Inaba and Ogawa strains were isolated. The highest mortality and the morbidity rate was 1.98% in 2013. The most cholera prevalent provinces in order of frequency were Baluchistan, Alborz, Gilan, Golestan and Qom, as well as Tehran. Inaba serotype was the most common cause of mortality and morbidity in 2013. Conclusion: These findings indicate significant outbreaks of cholera in some of the provinces of Iran and warrant appropriate treatment and preventive measures. PMID:27757199

  5. 19世纪中叶英国霍乱与公共卫生运动的兴起%Cholera and the Rise of Public Health Movement of Britain in the Mid-19th Century

    Institute of Scientific and Technical Information of China (English)

    毛利霞

    2016-01-01

    1831年霍乱传入英国,引起极大的社会恐慌。埃德温·查德威克调查后发现,霍乱极有可能与糟糕的城市状况有关,积极倡导公共卫生改革。1848年霍乱的再次暴发证实了卫生派的观点:霍乱严重的地区恰好是卫生状况糟糕的地区。在新闻界的宣传和社会各界的要求下,英国议会颁布法令,开展公共卫生运动来改善城市卫生状况,以此达到消除霍乱的目的。%Cholera which came in Britain in 1831 made great panic of the society.After surveying,Edwin Chadwick found that cholera had a potential relation to the bad urban conditions,and then promoted the reform of public health actively.The breaking out of cholera in 1848 in the second time confirmed the viewpoints of the faction of the health,that was,severe cholera areas happened to the bad health regions. On the propaganda of the press and the desire of all circles,the British parliaments promulgated the de-crees,and carried out public health movements to improve the urban health situations in order to eliminate the cholera.

  6. Reduced Susceptibility to Extended-Spectrum β-Lactams in Vibrio cholerae Isolated in Bangladesh

    Science.gov (United States)

    Ceccarelli, Daniela; Alam, Munirul; Huq, Anwar; Colwell, Rita R.

    2016-01-01

    β-lactams are antibiotic molecules able to inhibit cell wall biosynthesis. Among other mechanisms, resistance in Gram-negative bacteria is mostly associated with production of β-lactamase enzymes able to bind and hydrolyze the β-lactam ring. Extended-spectrum β-lactamases extend this ability also to third- and fourth-generation cephalosporins, as well as to carbapenems and monobactams. Vibrio cholerae is the causative agent of epidemic cholera and a public health burden for developing countries like Bangladesh. Although appropriate oral or intravenous rehydration is the therapy of choice for cholera, severe infections and V. cholerae-associated septicemia are treated with antimicrobial drugs, including doxycycline, erythromycin, azithromycin, ciprofloxacin, and/or third-generation cephalosporins. In the years after the introduction of antibiotics in clinical practice, V. cholerae developed resistance to commonly used drugs worldwide mostly through gene acquisition via horizontal gene transfer. Reduced susceptibility of V. cholerae to third-generation cephalosporins has been occasionally documented. However, carbapenemase-producing V. cholerae has been reported at higher rates than resistance to extended-spectrum β-lactams, mainly associated with blaNDM-1 emergence and successful plasmid dissemination. Recent findings suggest limited β-lactam resistance is present in V. cholerae O1 isolates collected during ecological and epidemiological surveillance in Bangladesh. However, a trend to intermediate-susceptibility insurgence was observed. Horizontal gene transfer of β-lactam resistance from enteric pathogens to environmental microorganisms should not be underrated, given the ability of V. cholerae to acquire new genetic information.

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

    Science.gov (United States)

    Unterweger, Daniel; Kitaoka, Maya; Miyata, Sarah T; Bachmann, Verena; Brooks, Teresa M; Moloney, Jessica; Sosa, Oscar; Silva, David; Duran-Gonzalez, Jorge; Provenzano, Daniele; Pukatzki, Stefan

    2012-01-01

    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.

  8. A combined vaccine approach against Vibrio cholerae and ETEC based on outer membrane vesicles.

    Science.gov (United States)

    Leitner, Deborah R; Lichtenegger, Sabine; Temel, Philipp; Zingl, Franz G; Ratzberger, Desiree; Roier, Sandro; Schild-Prüfert, Kristina; Feichter, Sandra; Reidl, Joachim; Schild, Stefan

    2015-01-01

    Enteric infections induced by pathogens like Vibrio cholerae and enterotoxigenic Escherichia coli (ETEC) remain a massive burden in developing countries with increasing morbidity and mortality rates. Previously, we showed that the immunization with genetically detoxified outer membrane vesicles (OMVs) derived from V. cholerae elicits a protective immune response based on the generation of O antigen antibodies, which effectively block the motility by binding to the sheathed flagellum. In this study, we investigated the potential of lipopolysaccharide (LPS)-modified and toxin negative OMVs isolated from V. cholerae and ETEC as a combined OMV vaccine candidate. Our results indicate that the immunization with V. cholerae or ETEC OMVs induced a species-specific immune response, whereas the combination of both OMV species resulted in a high-titer, protective immune response against both pathogens. Interestingly, the immunization with V. cholerae OMVs alone resulted in a so far uncharacterized and cholera toxin B-subunit (CTB) independent protection mechanism against an ETEC colonization. Furthermore, we investigated the potential use of V. cholerae OMVs as delivery vehicles for the heterologously expression of the ETEC surface antigens, CFA/I, and FliC. Although we induced a detectable immune response against both heterologously expressed antigens, none of these approaches resulted in an improved protection compared to a simple combination of V. cholerae and ETEC OMVs. Finally, we expanded the current protection model from V. cholerae to ETEC by demonstrating that the inhibition of motility via anti-FliC antibodies represents a relevant protection mechanism of an OMV-based ETEC vaccine candidate in vivo.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. A metalloprotease secreted by the type II secretion system links Vibrio cholerae with collagen.

    Science.gov (United States)

    Park, Bo R; Zielke, Ryszard A; Wierzbicki, Igor H; Mitchell, Kristie C; Withey, Jeffrey H; Sikora, Aleksandra E

    2015-03-01

    Vibrio cholerae is autochthonous to various aquatic niches and is the etiological agent of the life-threatening diarrheal disease cholera. The persistence of V. cholerae in natural habitats is a crucial factor in the epidemiology of cholera. In contrast to the well-studied V. cholerae-chitin connection, scarce information is available about the factors employed by the bacteria for the interaction with collagens. Collagens might serve as biologically relevant substrates, because they are the most abundant protein constituents of metazoan tissues and V. cholerae has been identified in association with invertebrate and vertebrate marine animals, as well as in a benthic zone of the ocean where organic matter, including collagens, accumulates. Here, we describe the characterization of the V. cholerae putative collagenase, VchC, encoded by open reading frame VC1650 and belonging to the subfamily M9A peptidases. Our studies demonstrate that VchC is an extracellular collagenase degrading native type I collagen of fish and mammalian origin. Alteration of the predicted catalytic residues coordinating zinc ions completely abolished the protein enzymatic activity but did not affect the translocation of the protease by the type II secretion pathway into the extracellular milieu. We also show that the protease undergoes a maturation process with the aid of a secreted factor(s). Finally, we propose that V. cholerae is a collagenovorous bacterium, as it is able to utilize collagen as a sole nutrient source. This study initiates new lines of investigations aiming to uncover the structural and functional components of the V. cholerae collagen utilization program.

  11. Reduced Susceptibility to Extended-Spectrum β-Lactams in Vibrio cholerae Isolated in Bangladesh.

    Science.gov (United States)

    Ceccarelli, Daniela; Alam, Munirul; Huq, Anwar; Colwell, Rita R

    2016-01-01

    β-lactams are antibiotic molecules able to inhibit cell wall biosynthesis. Among other mechanisms, resistance in Gram-negative bacteria is mostly associated with production of β-lactamase enzymes able to bind and hydrolyze the β-lactam ring. Extended-spectrum β-lactamases extend this ability also to third- and fourth-generation cephalosporins, as well as to carbapenems and monobactams. Vibrio cholerae is the causative agent of epidemic cholera and a public health burden for developing countries like Bangladesh. Although appropriate oral or intravenous rehydration is the therapy of choice for cholera, severe infections and V. cholerae-associated septicemia are treated with antimicrobial drugs, including doxycycline, erythromycin, azithromycin, ciprofloxacin, and/or third-generation cephalosporins. In the years after the introduction of antibiotics in clinical practice, V. cholerae developed resistance to commonly used drugs worldwide mostly through gene acquisition via horizontal gene transfer. Reduced susceptibility of V. cholerae to third-generation cephalosporins has been occasionally documented. However, carbapenemase-producing V. cholerae has been reported at higher rates than resistance to extended-spectrum β-lactams, mainly associated with blaNDM-1 emergence and successful plasmid dissemination. Recent findings suggest limited β-lactam resistance is present in V. cholerae O1 isolates collected during ecological and epidemiological surveillance in Bangladesh. However, a trend to intermediate-susceptibility insurgence was observed. Horizontal gene transfer of β-lactam resistance from enteric pathogens to environmental microorganisms should not be underrated, given the ability of V. cholerae to acquire new genetic information.

  12. Quorum sensing-regulated chitin metabolism provides grazing resistance to Vibrio cholerae biofilms.

    Science.gov (United States)

    Sun, Shuyang; Tay, Qi Xiang Martin; Kjelleberg, Staffan; Rice, Scott A; McDougald, Diane

    2015-08-01

    Association of Vibrio cholerae with chitinous surfaces of zooplankton is important for its persistence in marine environments, as it provides accessibility to nutrients and resistance to stresses. Predation by heterotrophic protists has a major impact on the survival of V. cholerae. V. cholerae forms biofilms as its main defensive strategy, and quorum sensing (QS) additionally regulates the production of antiprotozoal factors. The role of chitin and QS regulation in V. cholerae grazing resistance was investigated by exposing V. cholerae wild-type (WT) and QS mutant biofilms grown on chitin flakes to the bacteriotrophic, surface-feeding flagellate Rhynchomonas nasuta. V. cholerae formed more biofilm biomass on chitin flakes compared with nonchitinous surfaces. The growth of R. nasuta was inhibited by WT biofilms grown on chitin flakes, whereas the inhibition was attenuated in QS mutant biofilms. The chitin-dependent toxicity was also observed when the V. cholerae biofilms were developed under continuous flow or grown on a natural chitin source, the exoskeleton of Artemia. In addition, the antiprotozoal activity and ammonium concentration of V. cholerae biofilm supernatants were quantified. The ammonium levels (3.5 mM) detected in the supernatants of V. cholerae WT biofilms grown on chitin flakes were estimated to reduce the number of R. nasuta by >80% in add-back experiments, and the supernatant of QS mutant biofilms was less toxic owing to a decrease in ammonium production. Transcriptomic analysis revealed that the majority of genes involved in chitin metabolism and chemotaxis were significantly downregulated in QS mutant biofilms when grown on chitin compared with the WT biofilms.

  13. Reduced susceptibility to extended-spectrum β-lactams in V. cholerae isolated in Bangladesh

    Directory of Open Access Journals (Sweden)

    Daniela Ceccarelli

    2016-10-01

    Full Text Available β-lactams are antibiotic molecules able to inhibit cell wall biosynthesis. Among other mechanisms, resistance in Gram-negative bacteria is mostly associated with production of β-lactamase enzymes able to bind and hydrolyze the β-lactam ring. Extended-spectrum β-lactamases extend this ability also to 3rd- and 4th generation cephalosporins as well as to carbapenems and monobactams. V. cholerae is the causative agent of epidemic cholera and a public health burden for developing countries like Bangladesh. Although appropriate oral or intravenous rehydration is the therapy of choice for cholera, severe infections and V. cholerae associated septicemia are treated with antimicrobial drugs including doxycycline, erythromycin, azithromycin, ciprofloxacin and/or third-generation cephalosporins. In the years after introduction of antibiotics in clinical practice, V. cholerae developed resistance to commonly used drugs worldwide mostly through gene acquisition via horizontal gene transfer. Reduced susceptibility of V. cholerae to third-generation cephalosporins has been occasionally documented. However, carbapenemase-producing V. cholerae has been reported at higher rates than resistance to extended spectrum β-lactams, mainly associated with blaNDM-1 emergence and successful plasmid dissemination. Recent findings suggest limited β-lactam resistance is present in V. cholerae O1 isolates collected during ecological and epidemiological surveillance in Bangladesh. However a trend to intermediate-susceptibility insurgence was observed. Horizontal gene transfer of β-lactam resistance from enteric pathogens to environmental microorganisms should not be underrated, given the ability of V. cholerae to acquire new genetic information.

  14. Examining rainfall and cholera dynamics in Haiti using statistical and dynamic modeling approaches.

    Science.gov (United States)

    Eisenberg, Marisa C; Kujbida, Gregory; Tuite, Ashleigh R; Fisman, David N; Tien, Joseph H

    2013-12-01

    Haiti has been in the midst of a cholera epidemic since October 2010. Rainfall is thought to be associated with cholera here, but this relationship has only begun to be quantitatively examined. In this paper, we quantitatively examine the link between rainfall and cholera in Haiti for several different settings (including urban, rural, and displaced person camps) and spatial scales, using a combination of statistical and dynamic models. Statistical analysis of the lagged relationship between rainfall and cholera incidence was conducted using case crossover analysis and distributed lag nonlinear models. Dynamic models consisted of compartmental differential equation models including direct (fast) and indirect (delayed) disease transmission, where indirect transmission was forced by empirical rainfall data. Data sources include cholera case and hospitalization time series from the Haitian Ministry of Public Health, the United Nations Water, Sanitation and Health Cluster, International Organization for Migration, and Hôpital Albert Schweitzer. Rainfall data was obtained from rain gauges from the U.S. Geological Survey and Haiti Regeneration Initiative, and remote sensing rainfall data from the National Aeronautics and Space Administration Tropical Rainfall Measuring Mission. A strong relationship between rainfall and cholera was found for all spatial scales and locations examined. Increased rainfall was significantly correlated with increased cholera incidence 4-7 days later. Forcing the dynamic models with rainfall data resulted in good fits to the cholera case data, and rainfall-based predictions from the dynamic models closely matched observed cholera cases. These models provide a tool for planning and managing the epidemic as it continues.

  15. Flexibility of oral cholera vaccine dosing-a randomized controlled trial measuring immune responses following alternative vaccination schedules in a cholera hyper-endemic zone.

    Directory of Open Access Journals (Sweden)

    Suman Kanungo

    2015-03-01

    Full Text Available BACKGROUND: A bivalent killed whole cell oral cholera vaccine has been found to be safe and efficacious for five years in the cholera endemic setting of Kolkata, India, when given in a two dose schedule, two weeks apart. A randomized controlled trial revealed that the immune response was not significantly increased following the second dose compared to that after the first dose. We aimed to evaluate the impact of an extended four week dosing schedule on vibriocidal response. METHODOLOGY/PRINCIPAL FINDINGS: In this double blind randomized controlled non-inferiority trial, 356 Indian, non-pregnant residents aged 1 year or older were randomized to receive two doses of oral cholera vaccine at 14 and 28 day intervals. We compared vibriocidal immune responses between these schedules. Among adults, no significant differences were noted when comparing the rates of seroconversion for V. cholerae O1 Inaba following two dose regimens administered at a 14 day interval (55% vs the 28 day interval (58%. Similarly, no differences in seroconversion were demonstrated in children comparing the 14 (80% and 28 day intervals (77%. Following 14 and 28 day dosing intervals, vibriocidal response rates against V. cholerae O1 Ogawa were 45% and 49% in adults and 73% and 72% in children respectively. Responses were lower for V. cholerae O139, but similar between dosing schedules for adults (20%, 20% and children (28%, 20%. CONCLUSIONS/SIGNIFICANCE: Comparable immune responses and safety profiles between the two dosing schedules support the option for increased flexibility of current OCV dosing. Further operational research using a longer dosing regimen will provide answers to improve implementation and delivery of cholera vaccination in endemic and epidemic outbreak scenarios.

  16. Comparative genome analysis of VSP-II and SNPs reveals heterogenic variation in contemporary strains of Vibrio cholerae O1 isolated from cholera patients in Kolkata, India.

    Science.gov (United States)

    Imamura, Daisuke; Morita, Masatomo; Sekizuka, Tsuyoshi; Mizuno, Tamaki; Takemura, Taichiro; Yamashiro, Tetsu; Chowdhury, Goutam; Pazhani, Gururaja P; Mukhopadhyay, Asish K; Ramamurthy, Thandavarayan; Miyoshi, Shin-Ichi; Kuroda, Makoto; Shinoda, Sumio; Ohnishi, Makoto

    2017-02-13

    Cholera is an acute diarrheal disease and a major public health problem in many developing countries in Asia, Africa, and Latin America. Since the Bay of Bengal is considered the epicenter for the seventh cholera pandemic, it is important to understand the genetic dynamism of Vibrio cholerae from Kolkata, as a representative of the Bengal region. We analyzed whole genome sequence data of V. cholerae O1 isolated from cholera patients in Kolkata, India, from 2007 to 2014 and identified the heterogeneous genomic region in these strains. In addition, we carried out a phylogenetic analysis based on the whole genome single nucleotide polymorphisms to determine the genetic lineage of strains in Kolkata. This analysis revealed the heterogeneity of the Vibrio seventh pandemic island (VSP)-II in Kolkata strains. The ctxB genotype was also heterogeneous and was highly related to VSP-II types. In addition, phylogenetic analysis revealed the shifts in predominant strains in Kolkata. Two distinct lineages, 1 and 2, were found between 2007 and 2010. However, the proportion changed markedly in 2010 and lineage 2 strains were predominant thereafter. Lineage 2 can be divided into four sublineages, I, II, III and IV. The results of this study indicate that lineages 1 and 2-I were concurrently prevalent between 2007 and 2009, and lineage 2-III observed in 2010, followed by the predominance of lineage 2-IV in 2011 and continued until 2014. Our findings demonstrate that the epidemic of cholera in Kolkata was caused by several distinct strains that have been constantly changing within the genetic lineages of V. cholerae O1 in recent years.

  17. [On the epidemic of cholera and its prevention and control by the railway authorities in 1932].

    Science.gov (United States)

    Huang, H P; Song, M H

    2016-01-28

    In 1932, the epidemic of cholera in China was serious, spreading to all provinces nationwide, causing heavy casualties. In order to prevent cholera epidemics spread along the railway line, the National Government Ministry of Railways and the local railway administration had taken all countermeasures, including the promulgation of epidemic prevention laws and regulations, quarantine, isolated check-up, disinfection, vaccination and even interruption of traffic. The measures of railway authorities had achieved a certain success. In August 1932, cholera epidemic began to subside gradually.

  18. Characterization and Genetic Variation of Vibrio cholerae Isolated from Clinical and Environmental Sources in Thailand.

    Science.gov (United States)

    Siriphap, Achiraya; Leekitcharoenphon, Pimlapas; Kaas, Rolf S; Theethakaew, Chonchanok; Aarestrup, Frank M; Sutheinkul, Orasa; Hendriksen, Rene S

    2017-01-01

    Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found that the typical El Tor O1 strains were the major cause of clinical cholera during 1983-2000 with two Classical O1 strains detected in 2000. In 2004-2010, the El Tor variant strains revealed genotypes of the Classical biotype possessing either only ctxB or both ctxB and rstR while they harbored tcpA of the El Tor biotype. Thirty O1 and eleven O139 clinical strains carried CTXϕ (Cholera toxin) and tcpA as well four different pathogenic islands (PAIs). Beside non-O1/non-O139, the O1 environmental strains also presented chxA and Type Three Secretion System (TTSS). The in silico MultiLocus Sequence Typing (MLST) discriminated the O1 and O139 clinical strains from other serogroups and environmental strains. ST69 was dominant in the clinical strains belonging to the 7th pandemic clone. Non-O1/non-O139 and environmental strains showed various novel STs indicating genetic variation. Multidrug-resistant (MDR) strains were observed and conferred resistance to ampicillin, azithromycin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim and harboured variants of the SXT elements

  19. Characterization and Genetic Variation of Vibrio cholerae Isolated from Clinical and Environmental Sources in Thailand

    Science.gov (United States)

    Siriphap, Achiraya; Leekitcharoenphon, Pimlapas; Kaas, Rolf S.; Theethakaew, Chonchanok; Aarestrup, Frank M.; Sutheinkul, Orasa; Hendriksen, Rene S.

    2017-01-01

    Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found that the typical El Tor O1 strains were the major cause of clinical cholera during 1983–2000 with two Classical O1 strains detected in 2000. In 2004–2010, the El Tor variant strains revealed genotypes of the Classical biotype possessing either only ctxB or both ctxB and rstR while they harbored tcpA of the El Tor biotype. Thirty O1 and eleven O139 clinical strains carried CTXϕ (Cholera toxin) and tcpA as well four different pathogenic islands (PAIs). Beside non-O1/non-O139, the O1 environmental strains also presented chxA and Type Three Secretion System (TTSS). The in silico MultiLocus Sequence Typing (MLST) discriminated the O1 and O139 clinical strains from other serogroups and environmental strains. ST69 was dominant in the clinical strains belonging to the 7th pandemic clone. Non-O1/non-O139 and environmental strains showed various novel STs indicating genetic variation. Multidrug-resistant (MDR) strains were observed and conferred resistance to ampicillin, azithromycin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim and harboured variants of the SXT elements

  20. Development of a Vaccine Against Experimental Cholera and Escherichia coli Diarrheal Disease

    OpenAIRE

    Rappaport, R. S.; Bonde, G.

    1981-01-01

    The results of the present investigation indicate a simple approach to the development of a single-vaccine formula which may ultimately be used to confer protection against both cholera and certain types of Escherichia coli diarrheal disease in humans and domestic animals. The design of the vaccine is based on the well-documented ability of cholera antitoxin to neutralize both cholera and heat-labile E. coli enterotoxins (CT and LT, respectively) and on the ability of killed E. coli to enhanc...

  1. Geospatial and temporal patterns of annual cholera outbreaks in Matlab, Bangladesh

    Science.gov (United States)

    Majumder, M. S.; de Klerk, K.; Meyers, D.

    2012-12-01

    Cholera is a waterborne diarrheal disease endemic to Bangladesh, resulting in 1 million diagnoses annually. Such disease burden results in incalculable lost wages and treatment expenses, taken from the pockets of an already impoverished society. Two seasonally correlated outbreaks of cholera occur in Bangladesh every year. In the spring and early summer, the Bay of Bengal - which serves as a natural reservoir for the cholera bacteria - flows inland, causing the first outbreak amongst coastal communities. Waste containing the cholera bacteria enters the sewage system and remains untreated due to poor water and sanitation infrastructure. Therefore, during the following monsoon season, flooding of cholera-contaminated sewage into drinking water sources results in a second outbreak. Though considered common knowledge among local populations, this geographic and temporal progression has not been empirically verified in the current literature. The aim of our ongoing study is to systematically analyze the seasonal trajectory of endemic cholera in Bangladesh. This paper discusses the results obtained from a comprehensive survey of available cholera data from the International Centre of Diarrheal Disease Research, Bangladesh (ICDDR,B) in Matlab, Bangladesh. Matlab thana is a near-coastal community that consists of 142 villages. Monsoon season takes place from June through October. Due to its proximity to the Meghna River, which opens into the Bay of Bengal, the area experiences significant flooding during these months. Using 10 years of geographically referenced cholera data, cases were plotted in time and space. Preliminary patterns suggest that villages closer to the Meghna River experience the majority of the area's cholera outbreaks and that case count is highest in late spring and late fall. April/May and November/December represent 25% and 23% of total annual case counts respectively. Moreover, villages further from the coastline demonstrate 57% higher relative

  2. Genes de Vibrio cholerae involucrados en la tolerancia al cobre

    Directory of Open Access Journals (Sweden)

    Karen Marrero

    2010-01-01

    sensibilidad a cobre en aerobiosis y anaerobiosis. El principal sistema de resistencia a cobre en V. cholerae está constituido por la ATPasa transportadora de cationes CopA, codificada por VC2215, que funciona en aerobiosis y anaerobiosis. La proteína hipotética conservada codificada por VC2216 no es significativa en la resistencia a cobre en aerobiosis, pero en anaerobiosis es importante si CopA es funcional. La proteína codificada por los genes VCA0261-0260, anotados previamente como independientes, es importante en aerobiosis y a una alta concentración de cobre, pero en anaerobiosis su participación en la resistencia a cobre es solo evidente si CopA no es funcional. De esta manera, los sistemas de tolerancia a cobre en V. cholerae incluyen el producto de los genes VC2215, VC2216 y VCA0261-0260, que desempeñan diferentes funciones en diversas condiciones de cultivo.

  3. From Fall to Spring, or Spring to Fall? Seasonal Cholera Transmission Cycles and Implications for Climate Change

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Huq, A.; Colwell, R.; Islam, S.; WE Reason

    2010-12-01

    Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and the annual recurrence of this infectious disease in endemic areas continues to be of considerable interest to scientists and public health workers. Despite major advances in the ecological, and microbiological understanding of Vibrio cholerae, the causative agent, the role of underlying macro-scale hydroclimatic processes in propagating the disease in different seasons and years is not well understood. The incidence of cholera in the Bengal Delta region, the ‘native homeland’ of cholera, shows distinct biannual peaks in the southern floodplains, as opposed to single annual peaks in coastal areas and the northern parts of Bangladesh, as well as other cholera-endemic regions in the world. A coupled analysis of the regional hydroclimate and cholera incidence reveals a strong association of the spatio-temporal variability of incidence peaks with seasonal processes and extreme events. At a seasonal scale, the cycles indicate a spring-fall transmission pattern, contrary to the prevalent notion of a fall-spring transmission cycle. We show that the asymmetric seasonal hydroclimatology affects regional cholera dynamics by providing a coastal growth environment for bacteria in spring, while propagating transmission to fall by flooding. This seasonal interpretation of the progression of cholera has important implications, for formulating effective cholera intervention and mitigation efforts through improved water management and understanding the impacts of changing climate patterns on seasonal cholera transmission. (Water Environental Research Education Actionable Solutions Network)

  4. Linkage of Global Water Resources, Climate, and Human Health: A Conundrum for Which Cholera Offers a Paradigm (Invited)

    Science.gov (United States)

    Colwell, R.

    2010-12-01

    An environmental source of cholera was hypothesized as early as the late nineteenth century by Robert Koch. Standard bacteriological procedures for isolation of vibrios from environmental samples, including water, between epidemics generally were unsuccessful because Vibrio cholerae, a marine vibrio, enters into a dormant, "viable but nonculturable stage," when conditions are unfavorable for growth and reproduction. An association of Vibrio cholerae with zooplankton, notably copepods, has been established. Furthermore, the sporadicity and erraticity of cholera epidemics have been correlated with El Niño. Since zooplankton harbor the bacterium and zooplankton blooms follow phytoplankton blooms, remote sensing can be employed to predict cholera epidemics from sea surface temperature (SST), ocean height (OH), chlorophyll, and turbidity data. Cholera occurs seasonally in Bangladesh, with two annual peaks in the number of cases. From clinical remote sensing data, it has been found that SST, OH, and blooms of phytoplankton and zooplankton are correlated with cholera epidemics. Thus, selected climatological factors and incidence of V. cholerae can be recorded, bringing the potential of predicting conditions conducive to cholera outbreaks to reality. A simple filtration intervention takes into account the association of V. cholerae with plankton, and has proven to be a simple solution to the age-old problem of controlling this waterborne disease for villagers in remote regions of Bangladesh.

  5. Occurrence in Mexico, 1998-2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage.

    Science.gov (United States)

    Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A; Huq, Anwar; Sack, R Bradley; Colwell, Rita R; Cravioto, Alejandro

    2014-07-08

    The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ(-). Most CTXΦ(-) V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpA(ET) or a variant tcpA with noticeable sequence dissimilarity from tcpA(CL). The tcpA variants were not detected in 2005 after CTXΦ(+) ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005-2008 in Mexico were CTXΦ(+) ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ(-) ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ(+) ET isolated during 2004-2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru.

  6. Social and cultural features of cholera and shigellosis in peri-urban and rural communities of Zanzibar

    Directory of Open Access Journals (Sweden)

    Hutubessy Raymond

    2010-11-01

    Full Text Available Abstract Background Responding to the high burden of cholera in developing countries, the WHO now considers vaccination as a supplement to the provision of safe drinking water and improved sanitation in the strategy for cholera control in endemic settings. Cultural concepts of illness affect many aspects of public health. In the first step of a two-step strategy to examine determinants of cholera vaccine acceptance, this study identified social and cultural features of diarrhoeal illness for cholera control in endemic communities. Methods A cultural epidemiological study with locally adapted vignette-based interviews was conducted in two cholera-endemic communities of Zanzibar. A random sample of unaffected peri-urban (n = 179 and rural (n = 177 adults was interviewed to study community ideas of cholera and shigellosis, considering categories of distress, perceived causes, and help-seeking behaviour. Results Cholera was recognised by 88%. Symptoms of dehydration were most prominent in reports at the peri-urban site. Interference with work leading to strain on household finances was frequently emphasised. Dirty environment was the most prominent perceived cause, followed by unsafe drinking water and germ-carrying flies. Causes unrelated to the biomedical basis of cholera were reported more often by rural respondents. Rural women had more difficulty (20% to identify a cause than men (7.1%, p = 0.016. Peri-urban self treatment emphasised rehydration; the rural community preferred herbal treatment and antibiotics. Shigellosis was recognised by 70%. Fewer regarded it as very serious compared with cholera (76% vs. 97%, p Conclusions This study clarified local views of cholera and shigellosis relevant for diarrhoeal disease control in Zanzibar. The finding that rural women were less likely than men to specify causes of cholera suggests more attention to them is required. Better health education is needed for cholera in rural areas and for shigellosis

  7. 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

  8. Non-O1/non-O139 Vibrio cholerae carrying multiple virulence factors and V. cholerae O1 in the Chesapeake Bay, Maryland.

    Science.gov (United States)

    Ceccarelli, Daniela; Chen, Arlene; Hasan, Nur A; Rashed, Shah M; Huq, Anwar; Colwell, Rita R

    2015-03-01

    Non-O1/non-O139 Vibrio cholerae inhabits estuarine and coastal waters globally, but its clinical significance has not been sufficiently investigated, despite the fact that it has been associated with septicemia and gastroenteritis. The emergence of virulent non-O1/non-O139 V. cholerae is consistent with the recognition of new pathogenic variants worldwide. Oyster, sediment, and water samples were collected during a vibrio surveillance program carried out from 2009 to 2012 in the Chesapeake Bay, Maryland. V. cholerae O1 was detected by a direct fluorescent-antibody (DFA) assay but was not successfully cultured, whereas 395 isolates of non-O1/non-O139 V. cholerae were confirmed by multiplex PCR and serology. Only a few of the non-O1/non-O139 V. cholerae isolates were resistant to ampicillin and/or penicillin. Most of the isolates were sensitive to all antibiotics tested, and 77 to 90% carried the El Tor variant hemolysin gene hlyAET, the actin cross-linking repeats in toxin gene rtxA, the hemagglutinin protease gene hap, and the type 6 secretion system. About 19 to 21% of the isolates carried the neuraminidase-encoding gene nanH and/or the heat-stable toxin (NAG-ST), and only 5% contained a type 3 secretion system. None of the non-O1/non-O139 V. cholerae isolates contained Vibrio pathogenicity island-associated genes. However, ctxA, ace, or zot was present in nine isolates. Fifty-five different genotypes showed up to 12 virulence factors, independent of the source of isolation, and represent the first report of both antibiotic susceptibility and virulence associated with non-O1/non-O139 V. cholerae from the Chesapeake Bay. Since these results confirm the presence of potentially pathogenic non-O1/non-O139 V. cholerae, monitoring for total V. cholerae, regardless of serotype, should be done within the context of public health.

  9. A therapeutic chemical chaperone inhibits cholera intoxication and unfolding/translocation of the cholera toxin A1 subunit.

    Science.gov (United States)

    Taylor, Michael; Banerjee, Tuhina; Navarro-Garcia, Fernando; Huerta, Jazmin; Massey, Shane; Burlingame, Mansfield; Pande, Abhay H; Tatulian, Suren A; Teter, Ken

    2011-04-19

    Cholera toxin (CT) travels as an intact AB(5) protein toxin from the cell surface to the endoplasmic reticulum (ER) of an intoxicated cell. In the ER, the catalytic A1 subunit dissociates from the rest of the toxin. Translocation of CTA1 from the ER to the cytosol is then facilitated by the quality control mechanism of ER-associated degradation (ERAD). Thermal instability in the isolated CTA1 subunit generates an unfolded toxin conformation that acts as the trigger for ERAD-mediated translocation to the cytosol. In this work, we show by circular dichroism and fluorescence spectroscopy that exposure to 4-phenylbutyric acid (PBA) inhibited the thermal unfolding of CTA1. This, in turn, blocked the ER-to-cytosol export of CTA1 and productive intoxication of either cultured cells or rat ileal loops. In cell culture studies PBA did not affect CT trafficking to the ER, CTA1 dissociation from the holotoxin, or functioning of the ERAD system. PBA is currently used as a therapeutic agent to treat urea cycle disorders. Our data suggest PBA could also be used in a new application to prevent or possibly treat cholera.

  10. Gas phase characterization of the noncovalent quaternary structure of cholera toxin and the cholera toxin B subunit pentamer.

    Science.gov (United States)

    Williams, Jonathan P; Smith, Daniel C; Green, Brian N; Marsden, Brian D; Jennings, Keith R; Roberts, Lynne M; Scrivens, James H

    2006-05-01

    Cholera toxin (CTx) is an AB5 cytotonic protein that has medical relevance in cholera and as a novel mucosal adjuvant. Here, we report an analysis of the noncovalent homopentameric complex of CTx B chain (CTx B5) using electrospray ionization triple quadrupole mass spectrometry and tandem mass spectrometry and the analysis of the noncovalent hexameric holotoxin usingelectrospray ionization time-of-flight mass spectrometry over a range of pH values that correlate with those encountered by this toxin after cellular uptake. We show that noncovalent interactions within the toxin assemblies were maintained under both acidic and neutral conditions in the gas phase. However, unlike the related Escherichia coli Shiga-like toxin B5 pentamer (SLTx B), the CTx B5 pentamer was stable at low pH, indicating that additional interactions must be present within the latter. Structural comparison of the CTx B monomer interface reveals an additional alpha-helix that is absent in the SLTx B monomer. In silico energy calculations support interactions between this helix and the adjacent monomer. These data provide insight into the apparent stabilization of CTx B relative to SLTx B.

  11. Experimental Reservoirs of Human Pathogens: The Vibrio Cholerae Paradigm (7th Annual SFAF Meeting, 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, Rita [University of Maryland

    2012-06-01

    Rita Colwell on "Experimental Reservoirs of Human Pathogens: The Vibrio cholerae paradigm" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  12. Characterization and genetic variation of vibrio cholerae isolated from clinical and environmental sources in Thailand

    DEFF Research Database (Denmark)

    Siriphap, Achiraya; Leekitcharoenphon, Pimlapas; Kaas, Rolf Sommer

    2017-01-01

    Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic...... and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using...... online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found...

  13. H-NS: an overarching regulator of the Vibrio cholerae life cycle.

    Science.gov (United States)

    Ayala, Julio C; Silva, Anisia J; Benitez, Jorge A

    2017-01-01

    Vibrio cholerae has become a model organism for studies connecting virulence, pathogen evolution and infectious disease ecology. The coordinate expression of motility, virulence and biofilm enhances its pathogenicity, environmental fitness and fecal-oral transmission. The histone-like nucleoid structuring protein negatively regulates gene expression at multiple phases of the V. cholerae life cycle. Here we discuss: (i) the regulatory and structural implications of H-NS chromatin-binding in the two-chromosome cholera bacterium; (ii) the factors that counteract H-NS repression; and (iii) a model for the regulation of the V. cholerae life cycle that integrates H-NS repression, cyclic diguanylic acid signaling and the general stress response.

  14. 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.

  15. Color correlation for the recognition of Vibrio cholerae O1 in seawater

    Science.gov (United States)

    Mourino-Perez, Rosa R.; Alvarez-Borrego, Josue

    1999-07-01

    Application of color correlation optical systems for the recognition of Vibrio cholerae 01 in seawater samples with matched filters and phase only filters recorded in holographic plates in three channels (RGB).

  16. SEROLOGICAL DIAGNOSIS OF MODERN CHOLERA USING LIPOSOMAL ENTEROTOXIC DIAGNOSTICUM IN COMPLEMENT FIXATION TEST

    Directory of Open Access Journals (Sweden)

    I. V. Savelyeva

    2013-01-01

    Full Text Available Abstract. The possibility of serological diagnosis of cholera using cholera enterotoxic diagnostics kit in complement fixation test to detect anti-enterotoxic antibodies in sera of patients with cholera caused by hybrid variants of the El Tor biovar has been demonstrated. In patients with mild course of cholera anti-enterotoxic antibodies were detected in titres 1:50 and 1:200 in paired sera obtained on the 7th and 14th days of disease, respectively (fourfold titre increase. In patients with the course of medium severity 32-fold titre increase was recorded from the titre 1:100 in serum obtained on the fifth day of disease till the titre 1:3200 — on the twelfth day of disease. Antibodies titers reached 1:1600 and 1:800 were revealed in two medium course patients (adult and infant of 10 months on the sixth day of disease.

  17. Research Spotlight: Model suggests path to ending the ongoing Haitian cholera epidemic

    Science.gov (United States)

    Schultz, Colin

    2011-05-01

    Since early November 2010 a deadly cholera epidemic has been spreading across the Caribbean nation of Haiti, killing thousands of people and infecting hundreds of thousands. While infection rates are being actively monitored, health organizations have been left without a clear understanding of exactly how the disease has spread across Haiti. Cholera can spread through exposure to contaminated water, and the disease travels over long distances if an infected individual moves around the country. Using representations of these two predominant dispersion mechanisms, along with information on the size of the susceptible population, the number of infected individuals, and the aquatic concentration of the cholera-causing bacteria for more than 500 communities, Bertuzzo et al. designed a model that was able to accurately reproduce the progression of the Haitian cholera epidemic. (Geophysical Research Letters, doi:10.1029/2011GL046823, 2011)

  18. Antibiotic resistance of vibrio cholerae: special considerations of R-plasmids.

    Science.gov (United States)

    Kuwahara, S

    1978-09-01

    Studies on the transmission of R plasmid by conjugation between enterobacteria and vibrio or related bacteria were reviewed. The majority of the reports confirmed successful transmission from enterobacteria to Vibrio cholerae and related species, although the transmission frequencies were extremely low and the transmitted R plasmid was very unstable except for thermosensitive kanamycin plasmid and usual R plasmid coexisting with P plasmid. Strains of V. cholerae and Aeromonas liquefaciens as well as A. salmonicida bearing R plasmid were detected in nature. R plasmid was relatively unstable in V. cholerae strains with which transmission of R plasmid to enterobacteria was confirmed. At present, only 3 R plasmids have been obtained from naturally occurring strains of V. cholerae. Although the 2 European plasmids belong to the C incompatibility group with 98 megadalton closed covalent circular DNA molecule, one plasmid belongs to the J group with more than 25 megadalton molecular weight, and no CCC of satelite DNA was detected in bacteria harboring this plasmid.

  19. A comparison of biologically active elements in geese in relation to avian cholera

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Avian cholera caused an estimated mortality of between 166,000 to 197,000 migrating waterfowl in the Rainwater Basin of Nebraska in the 10-year period 1975 through...

  20. Disease dynamics in a coupled cholera model linking within-host and between-host interactions.

    Science.gov (United States)

    Wang, Xueying; Wang, Jin

    2016-09-19

    A new modelling framework is proposed to study the within-host and between-host dynamics of cholera, a severe intestinal infection caused by the bacterium Vibrio cholerae. The within-host dynamics are characterized by the growth of highly infectious vibrios inside the human body. These vibrios shed from humans contribute to the environmental bacterial growth and the transmission of the disease among humans, providing a link from the within-host dynamics at the individual level to the between-host dynamics at the population and environmental level. A fast-slow analysis is conducted based on the two different time scales in our model. In particular, a bifurcation study is performed, and sufficient and necessary conditions are derived that lead to a backward bifurcation in cholera epidemics. Our result regarding the backward bifurcation highlights the challenges in the prevention and control of cholera.

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

    Science.gov (United States)

    Weynberg, Karen D.; Voolstra, Christian R.; Neave, Matthew J.; Buerger, Patrick; van Oppen, Madeleine J. H.

    2015-01-01

    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. PMID:26644037

  2. Biological Activity of Recombinant Accessory Cholerae Enterotoxin (Ace on Rabbit Ileal Loops and Antibacterial Assay

    Directory of Open Access Journals (Sweden)

    Shaghayegh Anvari

    2012-01-01

    Full Text Available Objective: Vibrio cholerae (V. cholerae causes a potentially lethal disease named cholera. The cholera enterotoxin (CT is a major virulence factor of V. cholerae. In addition to CT, V. cholerae produces other putative toxins, such as the zonula occludens toxin (Zot and accessory cholera enterotoxin (Ace. The ace gene is the third gene of the V. cholerae virulence cassette. The Ace toxin alters ion transport, causes fluid accumulation in ligated rabbit ileal loops, and is a cause of mild diarrhea. The aim of this study is the cloning and overexpression of the ace gene into Escherichia coli (E. coli and determination of some characteristics of the recombinant Ace protein.Materials and Methods: In this experimental study, the ace gene was amplified from V. cholerae strain 62013, then cloned in a pET28a expression vector and transformed into an E. coli (DH5 α host strain. Subsequently, the recombinant vector was retransformed into E. coli BL21 for expression, induced by isopropythio-β-D-galctoside (IPTG at a different concentration, and examined by SDS-PAGE and Western blot. A rabbit ileal loop experiment was conducted. Antibacterial activity of the Ace protein was assessed for E. coli, Stapylococcus aureus (S. aureus, and Pseudomonas aeruginosa (P. aeruginosa.Results: The recombinant Ace protein with a molecular weight of 18 kDa (dimeric form was expressed in E. coli BL21. The Ace protein showed poor staining with Coomassie blue stain, but stained efficiently with silver stain. Western blot analysis showed that the recombinant Ace protein reacted with rabbit anti-V. cholerae polyclonal antibody. The Ace protein had antibacterial activity at a concentration of ≥200 μg/ml and caused significant fluid accumulation in the ligated rabbit ileal loop test.Conclusion: This study described an E. coli cloning and expression system (E. coli BL21- pET-28a-ace for the Ace protein of V. cholerae. We confirmed the antibacterial properties and enterotoxin

  3. Enhanced Detection of Vibrio Cholerae in Oyster Homogenate Based on Centrifugal Removal of Inhibitory Agents

    Science.gov (United States)

    Alexander, Donita; DePaola, Angelo; Young, Ronald B.

    1998-01-01

    The disease cholera, caused by Vibrio cholerae, has been associated with consumption of contaminated seafood, including raw oysters. Detection of V. cholerae in foods typically involves blending the oysters, diluting the homogenate in alkaline peptone water (APW), overnight enrichment, and isolation on selective agar. Unfortunately, the oyster homogenate must be diluted to large volumes because lower dilutions inhibit the growth of V. cholerae. The goals of this study were to develop an alternative to large dilutions and to evaluate the basis for the inhibition observed in lower dilutions of oyster homogenates. Centrifugation of oyster homogenates at 10,000 x g for 15 min, followed by enrichment of the resulting pellet in APW, was found to eliminate the inhibition of V. cholerae growth. Inhibition appears not to be due to competing microflora but to a component(s) released when V. cholerae grows in the presence of oyster homogenate. The inhibitory component(s) kills the V. cholerae after the cell concentration reaches > 10(exp 8) cells/mL, rather than initially preventing their growth. The pH also declines from 8.0 to 5.5 during this period; however, the pH decline by itself appears not to cause V. cholerae death. Seven strains of V. cholerae (01 and non-01) and two strains of V. vulnificus were susceptible to the inhibitory agent(s). However, other Vibrio and non-Vibrio species tested were not inhibited by the oyster homogenates. Based on digestion of oyster homogenates with pronase, trypsin and lipase, the inhibitory reaction involves a protein(s). In a preliminary trial with oyster homogenate seeded with 1 cfu/g of V. cholerae, the modified centrifugation technique detected a slightly higher percentage of samples at a 1:10 dilution than the standard FDA Bacteriological Analytical Method (BAM) detected in uncentrifuged oyster homogenate at a 1:100 dilution. V. cholerae in seeded samples could also be detected more frequently by the modified centrifugation method

  4. 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.

  5. Extraintestinal Infections Caused by Non-toxigenic Vibrio cholerae non-O1/non-O139.

    Science.gov (United States)

    Chowdhury, Goutam; Joshi, Sangeeta; Bhattacharya, Sanjay; Sekar, Uma; Birajdar, Balaji; Bhattacharyya, Arpita; Shinoda, Sumio; Ramamurthy, Thandavarayan

    2016-01-01

    Vibrio cholerae is an aerobic, sucrose fermentative Gram-negative bacterium that generally prevails in the environment. Pathogenic V. cholerae is well-known as causative agent of acute diarrhea. Apart from enteric infections, V. cholerae may also cause other diseases. However, their role in causing extraintestinal infections is not fully known as it needs proper identification and evaluation. Four cases of extraintestinal infections due to V. cholerae non-O1/non-O139 have been investigated. The isolates were screened for phenotypic and genetic characteristics with reference to their major virulence genes. Serologically distinct isolates harbored rtx, msh, and hly but lacked enteric toxin encoding genes that are generally present in toxigenic V. cholerae. Timely detection of this organism can prevent fatalities in hospital settings. The underlying virulence potential of V. cholerae needs appropriate testing and intervention.

  6. Seroepidemiologic survey of epidemic cholera in Haiti to assess spectrum of illness and risk factors for severe disease.

    Science.gov (United States)

    Jackson, Brendan R; Talkington, Deborah F; Pruckler, James M; Fouché, M D Bernadette; Lafosse, Elsie; Nygren, Benjamin; Gómez, Gerardo A; Dahourou, Georges A; Archer, W Roodly; Payne, Amanda B; Hooper, W Craig; Tappero, Jordan W; Derado, Gordana; Magloire, Roc; Gerner-Smidt, Peter; Freeman, Nicole; Boncy, Jacques; Mintz, Eric D

    2013-10-01

    To assess the spectrum of illness from toxigenic Vibrio cholerae O1 and risk factors for severe cholera in Haiti, we conducted a cross-sectional survey in a rural commune with more than 21,000 residents. During March 22-April 6, 2011, we interviewed 2,622 residents ≥ 2 years of age and tested serum specimens from 2,527 (96%) participants for vibriocidal and antibodies against cholera toxin; 18% of participants reported a cholera diagnosis, 39% had vibriocidal titers ≥ 320, and 64% had vibriocidal titers ≥ 80, suggesting widespread infection. Among seropositive participants (vibriocidal titers ≥ 320), 74.5% reported no diarrhea and 9.0% had severe cholera (reported receiving intravenous fluids and overnight hospitalization). This high burden of severe cholera is likely explained by the lack of pre-existing immunity in this population, although the virulence of the atypical El Tor strain causing the epidemic and other factors might also play a role.

  7. Cholera in Zimbabwe: Developing an Educational Response to a Health Crisis

    Science.gov (United States)

    Mandikonza, Caleb; Musindo, Beatrice; Taylor, Jim

    2011-01-01

    In February 2009, the World Health Organization (WHO) reported that the cholera epidemic in Zimbabwe had claimed 3,300 lives and infected 66,000 people--greater than the toll of that disease in the whole of Africa in most years. How is it possible that a disease such as cholera can have such a devastating effect in modern times? How should one…

  8. Development of lipopolysaccharide-mimicking peptides and their immunoprotectivity against Vibrio cholerae serogroup O1.

    Science.gov (United States)

    Mohammad Pour Ghazi, Fatemeh; Gargari, Seyed Latif Mousavi

    2016-11-01

    Vibrio cholerae serogroup O1 is the main causative agent of cholera diseases defined by life threatening rice watery diarrhea. Cholera routine vaccination has failed in controlling epidemics in developing countries because of their hard and expensive production. In this study, our aim was to investigate phage displayed mimotopes that could mimic V. cholerae lipopolysaccharide (LPS). Although LPS of Vibrio, as an endotoxin, can stimulate the immune system, thereby making it a suitable candidate for cholera vaccine, its toxicity remains as a main problem. Phage particles displaying 12 amino acid peptides were selected from phage library mimicking the antigenic epitopes of LPS from vibrio. The screening was carried out using single-domain antibody fragment VHH against LPS as target through three rounds of selection. Three clones with highest affinity to VHH were selected. To find out a new and efficient vaccine against cholera, these three phage particles containing high-affinity peptides were administered to mice to investigate the active and passive immunity. Out of 20 particles, three showed the highest affinity toward VHH. ELISA was carried out with immunized mice sera using LPS and three selected phages particles individually. ETEC, Shigella sonnei, and clinical isolates were used as bacterial targets. These three selected phages (individually or in combination) could stimulate mice immune system producing active and passive immunity. The mice immunized with phage particles could protect about 14 LD50 of V. cholerae. In conclusion, these peptides are mimicking LPS and can potentially act as vaccine candidates against V. cholerae. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  9. RNA thermometer controls temperature-dependent virulence factor expression in Vibrio cholerae.

    Science.gov (United States)

    Weber, Gregor G; Kortmann, Jens; Narberhaus, Franz; Klose, Karl E

    2014-09-30

    Vibrio cholerae is the bacterium that causes the diarrheal disease cholera. The bacteria experience a temperature shift as V. cholerae transition from contaminated water at lower temperatures into the 37 °C human intestine. Within the intestine, V. cholerae express cholera toxin (CT) and toxin-coregulated pilus (TCP), two main virulence factors required for disease. CT and TCP expression is controlled by the transcriptional activator protein ToxT. We identified an RNA thermometer motif in the 5' UTR of toxT, with a fourU anti-Shine-Dalgarno (SD) element that base pairs with the SD sequence to regulate ribosome access to the mRNA. RNA probing experiments demonstrated that the fourU element allowed access to the SD sequence at 37 °C but not at 20 °C. Moreover, mutations within the fourU element (U5C, U7C) that strengthened base-pairing between the anti-SD and SD sequences prevented access to the SD sequence even at 37 °C. Translation of ToxT-FLAG from the native toxT UTR was enhanced at 37 °C, compared with 25 °C in both Escherichia coli and V. cholerae. In contrast, the U5C, U7C UTR prevented translation of ToxT-FLAG even at 37 °C. V. cholerae mutants containing the U5C, U7C UTR variant were unable to colonize the infant mouse small intestine. Our results reveal a previously unknown regulatory mechanism consisting of an RNA thermometer that controls temperature-dependent translation of toxT, facilitating V. cholerae virulence at a relevant environmental condition found in the human intestine.

  10. Adhesins acquired in the aquatic environment and Vibrio cholerae colonization of intestinal cells

    OpenAIRE

    Vezzulli, Luigi; Repetto, Barbara; Pezzati, Elisabetta; Stauder, Monica; Giusto, Giovanni; Pruzzo, Carla

    2011-01-01

    Recent results for Vibrio cholerae interactions with bivalves and chitin-containing substrates are reviewed. Chitin, composed of b-1,4-linked N-acetylglucosamine residues, is one of the most abundant biopolymers in nature and the most abundant in the marine environment. V. cholerae connection to chitin is a well known phenomenon and one of the best documented examples of a successful bacteriasubstrate interaction, affecting both the lifestyle of the microorganisms and natural system functioni...

  11. The burden of diarrhoea, shigellosis, and cholera in North Jakarta, Indonesia: findings from 24 months surveillance

    Directory of Open Access Journals (Sweden)

    Lee Hyejon

    2005-10-01

    Full Text Available Abstract Background In preparation of vaccines trials to estimate protection against shigellosis and cholera we conducted a two-year community-based surveillance study in an impoverished area of North Jakarta which provided updated information on the disease burden in the area. Methods We conducted a two-year community-based surveillance study from August 2001 to July 2003 in an impoverished area of North Jakarta to assess the burden of diarrhoea, shigellosis, and cholera. At participating health care providers, a case report form was completed and stool sample collected from cases presenting with diarrhoea. Results Infants had the highest incidences of diarrhoea (759/1 000/year and cholera (4/1 000/year. Diarrhea incidence was significantly higher in boys under 5 years (387/1 000/year than girls under 5 years (309/1 000/year; p Shigella flexneri was the most common Shigella species isolated and 73% to 95% of these isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline but remain susceptible to nalidixic acid, ciprofloxacin, and ceftriaxone. We found an overall incidence of cholera of 0.5/1 000/year. Cholera was most common in children, with the highest incidence at 4/1 000/year in those less than 1 year of age. Of the 154 V. cholerae O1 isolates, 89 (58% were of the El Tor Ogawa serotype and 65 (42% were El Tor Inaba. Thirty-four percent of patients with cholera were intravenously rehydrated and 22% required hospitalization. V. parahaemolyticus infections were detected sporadically but increased from July 2002 onwards. Conclusion Diarrhoea causes a heavy public health burden in Jakarta particularly in young children. The impact of shigellosis is exacerbated by the threat of antimicrobial resistance, whereas that of cholera is aggravated by its severe manifestations.

  12. Human resources for health: lessons from the cholera outbreak in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Alexander Rosewell

    2013-07-01

    Full Text Available Issue: Papua New Guinea is striving to achieve the minimum core requirements under the International Health Regulations in surveillance and outbreak response, and has experienced challenges in the availability and distribution of health professionals. Context: Since mid-2009, a large cholera outbreak spread across lowland regions of the country and has been associated with more than 15 500 notifications at a case fatality ratio of 3.2%. The outbreak placed significant pressure on clinical and public health services. Action: We describe some of the challenges to cholera preparedness and response in this human resource-limited setting, the strategies used to ensure effective cholera management and lessons learnt. Outcome: Cholera task forces were useful to establish a clear system of leadership and accountability for cholera outbreak response and ensure efficiencies in each technical area. Cholera outbreak preparedness and response was strongest when human resource and health systems functioned well before the outbreak. Communication relied on coordination of existing networks and methods for empowering local leaders and villagers to modify behaviours of the population. Discussion: In line with the national health emergencies plan, the successes of human resource strategies during the cholera outbreak should be built upon through emergency exercises, especially in non-affected provinces. Population needs for all public health professionals involved in health emergency preparedness and response should be mapped, and planning should be implemented to increase the numbers in relevant areas. Human resource planning should be integrated with health emergency planning. It is essential to maintain and strengthen the human resource capacities and experiences gained during the cholera outbreak to ensure a more effective response to the next health emergency.

  13. Cholera Incidence and Mortality in Sub-Saharan African Sites during Multi-country Surveillance.

    Directory of Open Access Journals (Sweden)

    Delphine Sauvageot

    2016-05-01

    Full Text Available Cholera burden in Africa remains unknown, often because of weak national surveillance systems. We analyzed data from the African Cholera Surveillance Network (www.africhol.org.During June 2011-December 2013, we conducted enhanced surveillance in seven zones and four outbreak sites in Togo, the Democratic Republic of Congo (DRC, Guinea, Uganda, Mozambique and Cote d'Ivoire. All health facilities treating cholera cases were included. Cholera incidences were calculated using culture-confirmed cholera cases and culture-confirmed cholera cases corrected for lack of culture testing usually due to overwhelmed health systems and imperfect test sensitivity. Of 13,377 reported suspected cases, 34% occurred in Conakry, Guinea, 47% in Goma, DRC, and 19% in the remaining sites. From 0-40% of suspected cases were aged under five years and from 0.3-86% had rice water stools. Within surveillance zones, 0-37% of suspected cases had confirmed cholera compared to 27-38% during outbreaks. Annual confirmed incidence per 10,000 population was <0.5 in surveillance zones, except Goma where it was 4.6. Goma and Conakry had corrected incidences of 20.2 and 5.8 respectively, while the other zones a median of 0.3. During outbreaks, corrected incidence varied from 2.6 to 13.0. Case fatality ratios ranged from 0-10% (median, 1% by country.Across different African epidemiological contexts, substantial variation occurred in cholera incidence, age distribution, clinical presentation, culture confirmation, and testing frequency. These results can help guide preventive activities, including vaccine use.

  14. Reinitiation of Growth in Senescent Mouse Mammary Epithelium in Response to Cholera Toxin

    Science.gov (United States)

    Daniel, Charles W.; Silberstein, Gary B.; Strickland, Phyllis

    1984-06-01

    Several lines of mouse mammary tissue that had been serially transplanted until mitotic senescence was reached were exposed in vivo to plastic implants that slowly released cholera toxin. Gland tissue surrounding the implants displayed new end buds, indicating reinitiation of growth and morphogenesis. The ability of cholera toxin, which elevates intracellular adenosine 3',5'-monophosphate, to temporarily reverse the senescent phenotype suggests that this mitotic dysfunction results not from generalized cellular deterioration but from specific changes in cell regulation.

  15. Improved protection against cholera in adult rabbits with a combined flagellar-toxoid vaccine.

    OpenAIRE

    Resnick, I. G.; Ford, C W; Shackleford, G M; Berry, L J

    1980-01-01

    Ligated ileal loops of adult rabbits were used to evaluate the prophylactic potential against cholera of a combined vaccine consisting of toxin-free crude flagella (CF) and glutaraldehyde-derived cholera toxoid (TV). The resulting fluid accumulation ratios were compared with those in rabbits immunized with saline (controls) and with CF and TV alone. Data for single vaccines confirmed the superior protection effect of CF over TV. In rabbits vaccinated with both CF and TV, maximal fluid accumul...

  16. Hydroclimatological Controls of Endemic and Non-endemic Cholera of the 20th Century

    Science.gov (United States)

    Jutla, A. S.; Whitcombe, E.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat for the developing countries. Since the causative agent, Vibrio cholerae, is autochthonous to aquatic environment, it is not possible to eradicate the agent of the disease. Hydroclimatology based prediction and prevention strategies can be implemented in disease susceptible regions for reducing incidence rates. However, the precise role of hydrological and climatological processes, which will further aid in development of suitable prediction models, in creating spatial and temporal environmental conditions favorable for disease outbreak has not been adequately quantified. Here, we show distinction between seasonality and occurrence of cholera in epidemic and non-endemic regions. Using historical cholera mortality data, from the late 1800s for 27 locations in the Indian subcontinent, we show that non-endemic regions are generally located close to regional river systems but away from the coasts and are characterized by single sporadic outbreak in a given year. Increase in air temperature during the low river flow season increases evaporation, leading to an optimal salinity and pH required for bacterial growth. Thereafter, monsoonal rainfall, leads to interactions of contaminated river waters via human activity resulting in cholera epidemics. Endemic regions are located close to coasts where cholera outbreak occurs twice (spring and fall) in a year. Spring outbreak is generally associated with intrusion of bacterial seawater to inland whereas the fall peak is correlated with widespread flooding and cross-contamination of water resources via increased precipitation. This may be one of the first studies to hydroclimatologically quantitatively the seasonality of cholera in both endemic and non-endemic regions. Our results prompt the need of region and cause-specific prediction models for cholera, employing appropriate environmental determinants.

  17. Hydroclimatology of Dual-Peak Annual Cholera Incidence: Insights from a Spatially Explicit Model

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Gatto, M.; Casagrandi, R.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-12-01

    Cholera incidence in some regions of the Indian subcontinent may exhibit two annual peaks although the main environmental drivers that have been linked to the disease (e.g. sea surface temperature, zooplankton abundance, river discharge) peak once per year during the summer. An empirical hydroclimatological explanation relating cholera transmission to river flows and to the disease spatial spreading has been recently proposed. We specifically support and substantiate mechanistically such hypothesis by means of a spatially explicit model of cholera transmission. Our framework directly accounts for the role of the river network in transporting and redistributing cholera bacteria among human communities as well as for spatial and temporal annual fluctuations of precipitation and river flows. To single out the single out the hydroclimatologic controls on the prevalence patterns in a non-specific geographical context, we first apply the model to Optimal Channel Networks as a general model of hydrological networks. Moreover, we impose a uniform distribution of population. The model is forced by seasonal environmental drivers, namely precipitation, temperature and chlorophyll concentration in the coastal environment, a proxy for Vibrio cholerae concentration. Our results show that these drivers may suffice to generate dual-peak cholera prevalence patterns for proper combinations of timescales involved in pathogen transport, hydrologic variability and disease unfolding. The model explains the possible occurrence of spatial patterns of cholera incidence characterized by a spring peak confined to coastal areas and a fall peak involving inland regions. We then proceed applying the model to the specific settings of Bay of Bengal accounting for the actual river networks (derived from digital terrain map manipulations), the proper distribution of population (estimated from downscaling of census data based on remotely sensed features) and precipitation patterns. Overall our

  18. Avian cholera causes marine bird mortality in the Bering Sea of Alaska

    Science.gov (United States)

    Bodenstein, Barbara L.; Kimberlee Beckmen,; Gay Sheffield,; Kathy Kuletz,; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

    2015-01-01

    The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

  19. Cholera Incidence and Mortality in Sub-Saharan African Sites during Multi-country Surveillance

    Science.gov (United States)

    Sauvageot, Delphine; Njanpop-Lafourcade, Berthe-Marie; Akilimali, Laurent; Anne, Jean-Claude; Bidjada, Pawou; Bompangue, Didier; Bwire, Godfrey; Coulibaly, Daouda; Dengo-Baloi, Liliana; Dosso, Mireille; Orach, Christopher Garimoi; Inguane, Dorteia; Kagirita, Atek; Kacou-N’Douba, Adele; Keita, Sakoba; Kere Banla, Abiba; Kouame, Yao Jean-Pierre; Landoh, Dadja Essoya; Langa, Jose Paulo; Makumbi, Issa; Miwanda, Berthe; Malimbo, Muggaga; Mutombo, Guy; Mutombo, Annie; NGuetta, Emilienne Niamke; Saliou, Mamadou; Sarr, Veronique; Senga, Raphael Kakongo; Sory, Fode; Sema, Cynthia; Tante, Ouyi Valentin; Gessner, Bradford D.; Mengel, Martin A.

    2016-01-01

    Background Cholera burden in Africa remains unknown, often because of weak national surveillance systems. We analyzed data from the African Cholera Surveillance Network (www.africhol.org). Methods/ Principal findings During June 2011–December 2013, we conducted enhanced surveillance in seven zones and four outbreak sites in Togo, the Democratic Republic of Congo (DRC), Guinea, Uganda, Mozambique and Cote d’Ivoire. All health facilities treating cholera cases were included. Cholera incidences were calculated using culture-confirmed cholera cases and culture-confirmed cholera cases corrected for lack of culture testing usually due to overwhelmed health systems and imperfect test sensitivity. Of 13,377 reported suspected cases, 34% occurred in Conakry, Guinea, 47% in Goma, DRC, and 19% in the remaining sites. From 0–40% of suspected cases were aged under five years and from 0.3–86% had rice water stools. Within surveillance zones, 0–37% of suspected cases had confirmed cholera compared to 27–38% during outbreaks. Annual confirmed incidence per 10,000 population was <0.5 in surveillance zones, except Goma where it was 4.6. Goma and Conakry had corrected incidences of 20.2 and 5.8 respectively, while the other zones a median of 0.3. During outbreaks, corrected incidence varied from 2.6 to 13.0. Case fatality ratios ranged from 0–10% (median, 1%) by country. Conclusions/Significance Across different African epidemiological contexts, substantial variation occurred in cholera incidence, age distribution, clinical presentation, culture confirmation, and testing frequency. These results can help guide preventive activities, including vaccine use. PMID:27186885

  20. A cholera outbreak in Alborz Province, Iran: a matched case-control study

    Science.gov (United States)

    2016-01-01

    OBJECTIVES: A total of 229 confirmed cholera cases were reported in Alborz Province during an outbreak that lasted from June 2011 to August 2011. This study aimed to identify potential sources of transmission in order to determine suitable interventions in similar outbreaks. In other words, the lessons learned from this retrospective study can be utilized to manage future similar outbreaks. METHODS: An age-matched and sex-matched case-control study was conducted during the outbreak. For each case, two control subjects were selected from the neighborhood. A case of cholera was defined as a bacteriologically confirmed case with signs and symptoms of cholera. This study was conducted from June 14, 2011 through August 23, 2011. The data were analyzed by calculating odds ratios (ORs) using the logistic regression method. RESULTS: In this outbreak, 229 confirmed cholera cases were diagnosed. The following risk factors were found to be associated with cholera: consumption of unrefrigerated leftover food (OR, 3.05; 95% confidence interval [CI], 1.72 to 5.41), consumption of vegetables and fruits in the previous three days (OR, 2.75; 95% CI, 1.95 to 3.89), and a history of traveling in the previous five days (OR, 5.31; 95% CI, 2.21 to 9.72). CONCLUSIONS: Consumption of vegetables and fruits has remained an unresolved risk factor in cholera outbreaks in Iran in recent years. In order to reduce the risk of cholera, sanitary standards for fruits and vegetables should be observed at all points from production to consumption, the population should be educated regarding hygienic food storage during outbreaks, and sanitary standards should be maintained when traveling during cholera outbreaks. PMID:27188308

  1. Increased isolation frequency of toxigenic Vibrio cholerae O1 from environmental monitoring sites in Haiti.

    Science.gov (United States)

    Alam, Meer T; Weppelmann, Thomas A; Longini, Ira; De Rochars, Valery Madsen Beau; Morris, John Glenn; Ali, Afsar

    2015-01-01

    Since the identification of the first cholera case in 2010, the disease has spread in epidemic form throughout the island nation of Haiti; as of 2014, about 700,000 cholera cases have been reported, with over 8,000 deaths. While case numbers have declined, the more fundamental question of whether the causative bacterium, Vibrio cholerae has established an environmental reservoir in the surface waters of Haiti remains to be elucidated. In a previous study conducted between April 2012 and March 2013, we reported the isolation of toxigenic V. cholerae O1 from surface waters in the Ouest Department. After a second year of surveillance (April 2013 to March 2014) using identical methodology, we observed a more than five-fold increase in the number of water samples containing culturable V. cholerae O1 compared to the previous year (1.7% vs 8.6%), with double the number of sites having at least one positive sample (58% vs 20%). Both seasonal water temperatures and precipitation were significantly related to the frequency of isolation. Our data suggest that toxigenic V. cholerae O1 are becoming more common in surface waters in Haiti; while the basis for this increase is uncertain, our findings raise concerns that environmental reservoirs are being established.

  2. Vibrio cholerae and Vibrio parahaemolyticus detected in seafood products from Senegal.

    Science.gov (United States)

    Coly, Ignace; Sow, Amy Gassama; Seydi, Malang; Martinez-Urtaza, Jaime

    2013-12-01

    The detection of pathogenic Vibrio in seafood from Senegal has generated five food alerts in the European Union. To investigate the presence and abundance Vibrio cholerae and Vibrio parahaemolyticus in seafood and coastal and estuarine waters, 123 seafood samples and 52 water samples were collected during 2007-2009 from two large seafood markets in Dakar, and from different oceanic and estuarine areas of the country. V. parahaemolyticus was detected in 30.1% of seafood samples, whereas presence of V. cholerae was only found in 1.6%. In water samples, V. parahaemolyticus and V. cholerae were detected in 28.8% and 5.7% of the samples, respectively. Abundance of V. parahaemolyticus in seafood from the fishing areas ranged from 110 MPN/g. Densities of V. cholerae in the two positive seafood samples reached values of 0.36 and 0.61 MPN/g, repectively. V. parahaemolyticus strains were found to possess tlh, but not tdh and trh by polymerase chain reaction, and all the strains of V. cholerae were non-O1 or non-O139. These results suggest that the prevalence of high salinities in coastal and estuarine environments of Senegal limits the occurrence of V. parahaemolyticus and V. cholerae, despite warmer temperatures prevailing in seawater environments throughout the year. Furthermore, temperature abuse driven by a deficient cold chain over the distribution and retail sales may represent a major risk due to the postharvest multiplication of these Vibrio pathogens.

  3. 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.

  4. [ACTUAL PROBLEMS OF EPIDEMIOLOGIC CONTROL, LABORATORY DIAGNOSTICS AND PROPHYLAXIS OF CHOLERA IN RUSSIAN FEDERATION].

    Science.gov (United States)

    Onischenko, G G; Popova, A Yu; Kutyrev, V V; Smirnova, N I; Scherbakova, S A; Moskvitina, E A; Titova, S V

    2016-01-01

    Main problems of system of epidemiologic control for cholera active in Russian Federation, as well as laboratory diagnostics and vaccine prophylaxis of this especially dangerous infection, that had emerged in the contemporary period of the ongoing 7th pandemic of cholera, are discussed. Features of the genome of natural strains of Vibrio cholerae of El Tor biovar, that possess a poten- tial epidemic threat, as well as problems, that have emerged during isolation of these strains from samples of water of surface water bodies during their monitoring, are also examined. The main direction of enhancement of the system of epidemiologic control for cholera consist in develop- ment of a new algorithm of differentiation of administrative territories of Russian Federation by types of epidemic manifestations, as well as optimization of monitoring of environment objects. Integration of modern highly informative technologies into practice, as well as development of new generation diagnostic preparations based on DNA-chips and immunechips is necessary to increase effectiveness of the conducted operative and retrospective diagnostics in the contemporary period. Creation of national cholera vaccine, ensuring simultaneous protection from cholera causative agents of both O1 and O139 serogroups, is also required.

  5. 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.

  6. Role of 6-gingerol in reduction of cholera toxin activity in vitro and in vivo.

    Science.gov (United States)

    Saha, Pallashri; Das, Bornita; Chaudhuri, Keya

    2013-09-01

    Vibrio cholerae is one of the major bacterial pathogens responsible for the devastating diarrheal disease called cholera. Chemotherapy is often used against V. cholerae infections; however, the emergence of V. cholerae with multidrug resistance (MDR) toward the chemotherapeutic agents is a serious clinical problem. This scenario has provided us with the impetus to look into herbal remediation, especially toward blocking the action of cholera toxin (CT). Our studies were undertaken to determine the antidiarrheal potential of 6-gingerol (6G) on the basis of its effect on CT, the virulence factor secreted by V. cholerae. We report here that 6G binds to CT, hindering its interaction with the GM1 receptor present on the intestinal epithelial cells. The 50% inhibitory concentration (IC50) was determined to be 10 μg/ml. The detailed mechanistic study was conducted by enzyme-linked immunosorbent assay (ELISA), fluorescence spectroscopy, and isoelectric focusing. These results were validated with in vitro studies performed with the CHO, HeLa, and HT-29 cell lines, whereas a rabbit ileal loop assay was done to estimate the in vivo action, which confirms the efficacy of 6G in remediation of the choleragenic effects of CT. Thus, 6G can be an effective adjunctive therapy with oral rehydration solution for severe CT-mediated diarrhea.

  7. Identification of inhibitors against the potential ligandable sites in the active cholera toxin.

    Science.gov (United States)

    Gangopadhyay, Aditi; Datta, Abhijit

    2015-04-01

    The active cholera toxin responsible for the massive loss of water and ions in cholera patients via its ADP ribosylation activity is a heterodimer of the A1 subunit of the bacterial holotoxin and the human cytosolic ARF6 (ADP Ribosylation Factor 6). The active toxin is a potential target for the design of inhibitors against cholera. In this study we identified the potential ligandable sites of the active cholera toxin which can serve as binding sites for drug-like molecules. By employing an energy-based approach to identify ligand binding sites, and comparison with the results of computational solvent mapping, we identified two potential ligandable sites in the active toxin which can be targeted during structure-based drug design against cholera. Based on the probe affinities of the identified ligandable regions, docking-based virtual screening was employed to identify probable inhibitors against these sites. Several indole-based alkaloids and phosphates showed strong interactions to the important residues of the ligandable region at the A1 active site. On the other hand, 26 top scoring hits were identified against the ligandable region at the A1 ARF6 interface which showed strong hydrogen bonding interactions, including guanidines, phosphates, Leucopterin and Aristolochic acid VIa. This study has important implications in the application of hybrid structure-based and ligand-based methods against the identified ligandable sites using the identified inhibitors as reference ligands, for drug design against the active cholera toxin.

  8. Multi-species patterns of avian cholera mortality in Nebraska's rainwater basin

    Science.gov (United States)

    Blanchong, Julie A.; Samuel, M.D.; Mack, G.

    2006-01-01

    Nebraska's Rainwater Basin (RWB) is a key spring migration area for millions of waterfowl and other avian species. Avian cholera has been endemic in the RWB since the 1970s and in some years tens of thousands of waterfowl have died from the disease. We evaluated patterns of avian cholera mortality in waterfowl species using the RWB during the last quarter of the 20th century. Mortality patterns changed between the years before (1976 - 1988) and coincident with (1989 - 1999) the dramatic increases in lesser snow goose abundance and mortality. Lesser snow geese (Chen caerulescens caerulescens) have commonly been associated with mortality events in the RWB and are known to carry virulent strains of Pasteurella multocida, the agent causing avian cholera. Lesser snow geese appeared to be the species most affected by avian cholera during 1989 - 1999; however, mortality in several other waterfowl species was positively correlated with lesser snow goose mortality. Coincident with increased lesser snow goose mortality, spring avian cholera outbreaks were detected earlier and ended earlier compared to 1976 - 1988. Dense concentrations of lesser snow geese may facilitate intraspecific disease transmission through bird-to-bird contact and wetland contamination. Rates of interspecific avian cholera transmission within the waterfowl community, however, are difficult to determine.

  9. Multi-locus variable number tandem repeat analysis of 7th pandemic Vibrio cholerae

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    Lam Connie

    2012-05-01

    Full Text Available Abstract Background Seven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent. Cholera remains endemic in developing countries and is still a significant public health issue. In this study we use multilocus variable number of tandem repeats (VNTRs analysis (MLVA to discriminate between isolates of the 7th pandemic clone of Vibrio cholerae. Results MLVA of six VNTRs selected from previously published data distinguished 66 V. cholerae isolates collected between 1961–1999 into 60 unique MLVA profiles. Only 4 MLVA profiles consisted of more than 2 isolates. The discriminatory power was 0.995. Phylogenetic analysis showed that, except for the closely related profiles, the relationships derived from MLVA profiles were in conflict with that inferred from Single Nucleotide Polymorphism (SNP typing. The six SNP groups share consensus VNTR patterns and two SNP groups contained isolates which differed by only one VNTR locus. Conclusions MLVA is highly discriminatory in differentiating 7th pandemic V. cholerae isolates and MLVA data was most useful in resolving the genetic relationships among isolates within groups previously defined by SNPs. Thus MLVA is best used in conjunction with SNP typing in order to best determine the evolutionary relationships among the 7th pandemic V. cholerae isolates and for longer term epidemiological typing.

  10. Evaluation of enteric-coated tablets as a whole cell inactivated vaccine candidate against Vibrio cholerae.

    Science.gov (United States)

    Fernández, Sonsire; Año, Gemma; Castaño, Jorge; Pino, Yadira; Uribarri, Evangelina; Riverón, Luis A; Cedré, Bárbara; Valmaseda, Tania; Falero, Gustavo; Pérez, José L; Infante, Juan F; García, Luis G; Solís, Rosa L; Sierra, Gustavo; Talavera, Arturo

    2013-01-01

    A vaccine candidate against cholera was developed in the form of oral tablets to avoid difficulties during application exhibited by current whole cell inactivated cholera vaccines. In this study, enteric-coated tablets were used to improve the protection of the active compound from gastric acidity. Tablets containing heat-killed whole cells of Vibrio cholerae strain C7258 as the active pharmaceutical compound was enteric-coated with the polymer Kollicoat(®) MAE-100P, which protected them efficiently from acidity when a disintegration test was carried out. Enzyme-linked immunosorbent assay (ELISA) anti-lipopolysaccharide (LPS) inhibition test and Western blot assay revealed the presence of V. cholerae antigens as LPS, mannose-sensitive haemagglutinin (MSHA) and outer membrane protein U (Omp U) in enteric-coated tablets. Immunogenicity studies (ELISA and vibriocidal test) carried out by intraduodenal administration in rabbits showed that the coating process of tablets did not affect the immunogenicity of V. cholerae-inactivated cells. In addition, no differences were observed in the immune response elicited by enteric-coated or uncoated tablets, particularly because the animal model and immunization route used did not allow discriminating between acid resistances of both tablets formulations in vivo. Clinical studies with volunteers will be required to elucidate this aspect, but the results suggest the possibility of using enteric-coated tablets as a final pharmaceutical product for a cholera vaccine.

  11. Genetic Profile of IS1004 among Environmental Vibrio cholerae Isolated from Surface Water Sources in Iran

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    Bita Bakhshi B

    2013-03-01

    Full Text Available AbstractBackground and objective: Vibrio cholerae includes toxigenic and non-toxigenic serotypes. Non O1-non O139 serotypes are non toxigenic and do not have any role in cholera epidemics or pandemics all over the world. Different typing methods are widely used for molecular epidemiological investigations of clinical and environmental V. cholerae. The aim of this study is to investigate the genetic relatedness of environmental isolates of this bacterium using IS1004 profiling as an epidemiological marker. Materials and methods: Environmental samples collected from surface water sources in Tehran and cultured of TCBS agar after filtration. One single colony on TCBS was selected and cultured on BHI agar after which the cultures were used for biochemical diagnostic tests and serogroupings. DNA was isolated and used for PCR confirmation of V. cholerae isolates and wbeT gene. Genetic relatedness of isolates was determined using southern blot analysis. Results: From total 20 environmental V. cholerae identified in this study no wbeT gene was detected for the isolates. A total of 7 different banding patterns were obtained for the isolates while other 13 isolates identified as non-typeable by this method. Comparison with our previous studies indicated no identical pattern with clinical V. cholerae isolates. Conclusion: Differences in the banding pattern of IS1004 revealed a high heterogeneity among the isolates from surface water sources in Iran while these heterogenic isolates do not have any genetic relatedness with clinical isolates.

  12. Immune Responses to an Oral Cholera Vaccine in Internally Displaced Persons in South Sudan.

    Science.gov (United States)

    Iyer, Anita S; Bouhenia, Malika; Rumunu, John; Abubakar, Abdinasir; Gruninger, Randon J; Pita, Jane; Lino, Richard Lako; Deng, Lul L; Wamala, Joseph F; Ryan, Edward T; Martin, Stephen; Legros, Dominique; Lessler, Justin; Sack, David A; Luquero, Francisco J; Leung, Daniel T; Azman, Andrew S

    2016-10-24

    Despite recent large-scale cholera outbreaks, little is known about the immunogenicity of oral cholera vaccines (OCV) in African populations, particularly among those at highest cholera risk. During a 2015 preemptive OCV campaign among internally displaced persons in South Sudan, a year after a large cholera outbreak, we enrolled 37 young children (1-5 years old), 67 older children (6-17 years old) and 101 adults (≥18 years old), who received two doses of OCV (Shanchol) spaced approximately 3 weeks apart. Cholera-specific antibody responses were determined at days 0, 21 and 35 post-immunization. High baseline vibriocidal titers (>80) were observed in 21% of the participants, suggesting recent cholera exposure or vaccination. Among those with titers ≤80, 90% young children, 73% older children and 72% adults seroconverted (≥4 fold titer rise) after the 1(st) OCV dose; with no additional seroconversion after the 2(nd) dose. Post-vaccination immunological endpoints did not differ across age groups. Our results indicate Shanchol was immunogenic in this vulnerable population and that a single dose alone may be sufficient to achieve similar short-term immunological responses to the currently licensed two-dose regimen. While we found no evidence of differential response by age, further immunologic and epidemiologic studies are needed.

  13. Neutrophils Are Essential for Containment of Vibrio cholerae to the Intestine during the Proinflammatory Phase of Infection

    OpenAIRE

    Queen, Jessica; Satchell, Karla J Fullner

    2012-01-01

    Cholera is classically considered a noninflammatory diarrheal disease, in comparison to invasive enteric organisms, although there is a low-level proinflammatory response during early infection with Vibrio cholerae and a strong proinflammatory reaction to live attenuated vaccine strains. Using an adult mouse intestinal infection model, this study examines the contribution of neutrophils to host defense to infection. Nontoxigenic El Tor O1 V. cholerae infection is characterized by the upregula...

  14. Whole-Genome Sequencing of Vibrio cholerae O1 El Tor Strains Isolated in Ukraine (2011) and Russia (2014)

    Science.gov (United States)

    Smirnova, Nina I.; Agafonova, Elena Y.; Shchelkanova, Elena Y.; Alkhova, Zhanna V.; Kutyrev, Vlad