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Sample records for cholerae cytolysin promotes

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Rai, Anand Kumar; Chattopadhyay, Kausik

    2016-06-01

    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. PMID:27150630

  4. The Relationship between Glycan Binding and Direct Membrane Interactions in Vibrio cholerae Cytolysin, a Channel-forming Toxin.

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    De, Swastik; Bubnys, Adele; Alonzo, Francis; Hyun, Jinsol; Lary, Jeffrey W; Cole, James L; Torres, Victor J; Olson, Rich

    2015-11-20

    Bacterial pore-forming toxins (PFTs) are structurally diverse pathogen-secreted proteins that form cell-damaging channels in the membranes of host cells. Most PFTs are released as water-soluble monomers that first oligomerize on the membrane before inserting a transmembrane channel. To modulate specificity and increase potency, many PFTs recognize specific cell surface receptors that increase the local toxin concentration on cell membranes, thereby facilitating channel formation. Vibrio cholerae cytolysin (VCC) is a toxin secreted by the human pathogen responsible for pandemic cholera disease and acts as a defensive agent against the host immune system. Although it has been shown that VCC utilizes specific glycan receptors on the cell surface, additional direct contacts with the membrane must also play a role in toxin binding. To better understand the nature of these interactions, we conducted a systematic investigation of the membrane-binding surface of VCC to identify additional membrane interactions important in cell targeting. Through cell-based assays on several human-derived cell lines, we show that VCC is unlikely to utilize high affinity protein receptors as do structurally similar toxins from Staphylococcus aureus. Next, we identified a number of specific amino acid residues that greatly diminish the VCC potency against cells and investigated the interplay between glycan binding and these direct lipid contacts. Finally, we used model membranes to parse the importance of these key residues in lipid and cholesterol binding. Our study provides a complete functional map of the VCC membrane-binding surface and insights into the integration of sugar, lipid, and cholesterol binding interactions. PMID:26416894

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

    Science.gov (United States)

    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.

  6. Cholera

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    ... in various settings, either in the form of reactive campaigns in areas experiencing an outbreak or pre- ... to: support the design and implementation of global strategies to contribute to capacity development for cholera prevention ...

  7. Cholera

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    ... has it), do not offer them. previous continue Prevention Some countries have cholera vaccines that can help ... ON THIS TOPIC Staying Healthy While You Travel Dengue Fever Malaria Typhoid Fever Ebola First Aid: Diarrhea ...

  8. Structure of Vibrio cholerae ribosome hibernation promoting factor

    International Nuclear Information System (INIS)

    The X-ray crystal structure of ribosome hibernation promoting factor from V. cholerae has been determined at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The X-ray crystal structure of ribosome hibernation promoting factor (HPF) from Vibrio cholerae is presented at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The asymmetric unit contained two molecules of HPF linked by four Co atoms. The metal-binding sites observed in the crystal are probably not related to biological function. The structure of HPF has a typical β–α–β–β–β–α fold consistent with previous structures of YfiA and HPF from Escherichia coli. Comparison of the new structure with that of HPF from E. coli bound to the Thermus thermophilus ribosome [Polikanov et al. (2012 ▶), Science, 336, 915–918] shows that no significant structural changes are induced in HPF by binding

  9. 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.

  10. 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.

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

    Science.gov (United States)

    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.

  12. 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.

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

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    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.

  14. Requirements for Vibrio cholerae HapR Binding and Transcriptional Repression at the hapR Promoter Are Distinct from Those at the aphA Promoter

    OpenAIRE

    Lin, Wei; Kovacikova, Gabriela; Skorupski, Karen

    2005-01-01

    Virulence gene expression in certain strains of Vibrio cholerae is regulated in response to cell density by a quorum-sensing cascade that influences the levels of the LuxR homolog HapR through small regulatory RNAs that control the stability of its message. At high cell density, HapR represses the expression of the gene encoding the virulence gene activator AphA by binding to a site between −85 and −58 in the aphA promoter. We show here that a second binding site for HapR lies within the hapR...

  15. Drinking cholera

    DEFF Research Database (Denmark)

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

    2015-01-01

    Objectives: To measure the salinity levels of common water sources in coastal Bangladesh andexplore perceptions of water palatability among the local population to investigate the plausibility oflinking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Me...

  16. Cranberry extract standardized for proanthocyanidins promotes the immune response of Caenorhabditis elegans to Vibrio cholerae through the p38 MAPK pathway and HSF-1.

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    Jessica Dinh

    Full Text Available Botanicals are rich in bioactive compounds, and some offer numerous beneficial effects to animal and human health when consumed. It is well known that phytochemicals in cranberries have anti-oxidative and antimicrobial activities. Recently, an increasing body of evidence has demonstrated that cranberry phytochemicals may have potential benefits that promote healthy aging. Here, we use Caenorhabditis elegans as a model to show that water-soluble cranberry extract standardized to 4.0% proanthocyanidins (WCESP, a major component of cranberries, can enhance host innate immunity to resist against Vibrio cholerae (V. cholerae; wild type C6706 (O1 El Tor biotype infection. Supplementation of WCESP did not significantly alter the intestinal colonization of V. cholerae, but upregulated the expression of C. elegans innate immune genes, such as clec-46, clec-71, fmo-2, pqn-5 and C23G10.1. Additionally, WCESP treatment did not affect the growth of V. cholerae and expression of the major bacterial virulence genes, and only slightly reduced bacterial colonization within C. elegans intestine. These findings indicate that the major components of WCESP, including proanthocyanidins (PACs, may play an important role in enhancing the host innate immunity. Moreover, we engaged C. elegans mutants and identified that the p38 MAPK signaling, insulin/IGF-1 signaling (IIS, and HSF-1 play pivotal roles in the WCESP-mediated host immune response. Considering the level of conservation between the innate immune pathways of C. elegans and humans, the results of this study suggest that WCESP may also play an immunity-promoting role in higher order organisms.

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

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    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 < 40 nm spatial resolution on a 50 ms timescale. Single-molecule trajectory analysis reveals that TcpP diffusion is heterogeneous and can be described by three populations of TcpP motion: one fast, one slow, and one immobile. By comparing TcpP diffusion in wild-type V. 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.

  18. Vibrio Cholerae

    OpenAIRE

    Sri Amelia

    2006-01-01

    Vibrio cholerae adalah salah satu bakteri yang masuk dalam family Vibrionaceae selain dari Aeromonas dan Plesiomonas, dan merupakan bagian dari genus Vibrio. Bakteri ini pertama kali ditemukan oleh Robert Koch pada tahun 1884 dan sangat penting dalam dunia kedokteran karena menyebabkan penyakit kolera, oleh Sri Amelia

  19. 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...

  20. Vibrio cholerae Biofilms and Cholera Pathogenesis.

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    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.

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

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    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.

  2. Cholera outbreaks in Africa.

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    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

  3. Cholera in Azov area

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    O. N. Domashenko

    2015-07-01

    Full Text Available 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 waters of the city. Typical and watery diarrhoea, vomiting, abdominal pain and lack of normal body temperature, dehydration syndrome, characterized clinical cholera for adults in most cases. The mean duration of diarrhoea was 6,6 days. At 46.9% observed atypical symptoms in 10 (31,3% – abdominal pain (1 patient cramping in 7 cases, localized in the epigastria region, at 2-over stomach. In 5 patients (15,6% had an increase in body temperature to 37,2–37,7 degrees Celsius. In 15 (46,9% patients had severe nausea accompanied by vomiting. Easy for cholera was observed in 1 (3.1%, moderate – in 14 (43,8%, heavy – in 17 (53,1% patients. Dehydration I level is set at 4 (12,5%, II – from 6 (18,7%, III – in 18 (56,3%, IV – 4 (12,5% patients. Cholera outbreak was characterized by a predominance of severe disease and severe dehydration (III and IV, which was observed in 68.8% of patients. The decisive factor in the treatment of cholera patients was initiated in a timely manner rehydration therapy, in particular the introduction of the solution «Trisol». Against the background of rehydration therapy hyperkalaemia was observed in 9,4% of cases, vascular rehydration at 9,4%, the cell rehydration in 3,1% of patients. Fatal accidents cholera outbreaks have not been observed. Conclusion. Clinical diagnosis of cholera and the provision of medical care in the prehospital phase were poor, indicating the need for systematic conducting training seminars among experts

  4. 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.

  5. Stabile kloningsvektorer til Vibrio cholerae

    OpenAIRE

    Cohen, Malene; Jakobsen, Henrik; Larsen, Marie B.; Rasmussen, Maria H; Schrøder, Nanna B.

    2005-01-01

    Vi har forsøgt at konstruere stabile, plasmidbaserede ekspressions-/kloningsvektorer til Vibrio cholerae. Ideelt burde sådanne vektorer baseres på naturlige plasmider fra Vibrio cholerae, men idet Vibrio cholerae sjældent indeholder plasmider, tog vi i stedet udgangspunkt i velkarakteriserede kloningsvektorer fra Escherichia coli. I projektet undersøges fire kloningsvektorer med hver deres karakteristika. Det lykkedes at indføre dem i Vibrio cholerae. Med udgangspunkt i den ene vektor vises, ...

  6. Antimicrobial drugs for treating cholera

    OpenAIRE

    Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

    2014-01-01

    Background Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. Objectives To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are diffe...

  7. 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.

  8. 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.

  9. Differential endometrial cell sensitivity to a cholesterol-dependent cytolysin links Trueperella pyogenes to uterine disease in cattle.

    Science.gov (United States)

    Amos, Matthew R; Healey, Gareth D; Goldstone, Robert J; Mahan, Suman M; Düvel, Anna; Schuberth, Hans-Joachim; Sandra, Olivier; Zieger, Peter; Dieuzy-Labaye, Isabelle; Smith, David G E; Sheldon, Iain Martin

    2014-03-01

    Purulent disease of the uterus develops in 40% of dairy cows after parturition, when the epithelium of the endometrium is disrupted to expose the underlying stroma to bacteria. The severity of endometrial pathology is associated with isolation of Trueperella pyogenes. In the present study, T. pyogenes alone caused uterine disease when infused into the uterus of cattle where the endometrial epithelium was disrupted. The bacterium secretes a cholesterol-dependent cytolysin, pyolysin (PLO), and the plo gene was identical and the plo gene promoter was highly similar amongst 12 clinical isolates of T. pyogenes. Bacteria-free filtrates of the T. pyogenes cultures caused hemolysis and endometrial cytolysis, and PLO was the main cytolytic agent, because addition of anti-PLO antibody prevented cytolysis. Similarly, a plo-deletion T. pyogenes mutant did not cause hemolysis or endometrial cytolysis. Endometrial stromal cells were notably more sensitive to PLO-mediated cytolysis than epithelial or immune cells. Stromal cells also contained more cholesterol than epithelial cells, and reducing stromal cell cholesterol content using cyclodextrins protected against PLO. Although T. pyogenes or plo-deletion T. pyogenes stimulated accumulation of inflammatory mediators, such as IL-1beta, IL-6, and IL-8, from endometrium, PLO did not stimulate inflammatory responses by endometrial or hematopoietic cells, or in vitro organ cultures of endometrium. The marked sensitivity of stromal cells to PLO-mediated cytolysis provides an explanation for how T. pyogenes acts as an opportunistic pathogen to cause pathology of the endometrium once the protective epithelium is lost after parturition.

  10. 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.

  11. Vibrio cholerae O1 lineages driving cholera outbreaks during seventh cholera pandemic in Ghana.

    Science.gov (United States)

    Thompson, Cristiane C; Freitas, Fernanda S; Marin, Michel A; Fonseca, Erica L; Okeke, Iruka N; Vicente, Ana Carolina P

    2011-12-01

    In recent years, the frequency of cholera epidemics across Africa has increased significantly with thousands of people dying each year. However, there still exists a lack of information concerning the Vibrio cholerae O1 lineages driving early and contemporary epidemics since the seventh cholera pandemic started in the continent. This compromises the understanding of the forces determining the epidemiology of cholera in Africa and its control. This study aimed to analyze a collection of V. cholerae O1 strains from the beginning of the seventh cholera pandemic in Ghana and to compare them with recent isolates to understand the evolution of the cholera epidemic in Ghana. V. cholerae O1 strains were characterized by means of Multilocus Sequence Analysis (MLSA), genes from the virulence core genome (VCG), and genes related to the choleragenic phenotype. Our results revealed two major clusters of Ghanaian V. cholerae O1 strains, El Tor and Amazonia/Ghana. Concerning the virulence genes, all strains harbored the set of VCG and most were positive for VSP-II genomic island. The ctxB gene of the contemporary strains was characterized as Altered El Tor. The strains from 1970 to 1980 were susceptible to all antibiotics tested, except for the Amazonia/Ghana cluster that was resistant to aminoglycosides and carried the class 2 integron with the sat2-aadA1 arrangement. This study showed that distinct V. cholerae O1 were the determinants of cholera outbreaks in Ghana. Thus, in endemic regions, such as Africa, cholera can be caused by various V. cholerae O1 genotypes. PMID:21896336

  12. 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.

  13. Cholera in 1994. Part I.

    Science.gov (United States)

    1995-07-14

    In 1994, Vibrio cholerae O1 biotype El Tor, the agent responsible for the seventh cholera pandemic which began in 1961, continued to spread in all regions of the world (Map 1). In all, 384,403 cholera cases were officially reported to WHO in 1994 (a 2% increase over 1993), reversing the downward trend which started in 1992. A total of 10,692 deaths were reported in 1994, increasing the reported global case-fatality ratio (CFR) to 2.8% from 1.8% in 1993. Cholera cases were notified from 94 countries/areas, the highest number ever reporting in one year. (Table 1 and Fig. 1). The year was marked by the dramatic cholera outbreak that devastated the Rwandan refugee camps in Goma, Zaire in July. Major outbreaks also affected Afghanistan, Brazil, Guinea, Guinea-Bissau and Somalia. Africa reported a rise in the number of cholera cases, and was the continent accounting for the largest proportion of all reported cases. The incidence of cholera cases in the Americas continued to fall and reported CFR was the lowest recorded since the disease reached Latin America in 1991. Asia reported a 17% increase in cholera cases compared with 1993. Europe, which usually reports only imported cases, registered a significant increase in the number of indigenous cholera cases. Oceania reported 6 cases, 5 of which were imported, and no deaths (Figs. 2 and 3). The new V. cholerae strain O139 (Bengal) has affected 10 countries in Asia since it was first detected in India at PMID:7544150

  14. 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.

  15. 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.

  16. 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.

  17. Cholera: foodborne transmission and its prevention.

    Science.gov (United States)

    Estrada-García, T; Mintz, E D

    1996-10-01

    The last several years have witnessed a tremendous increase in reported cholera cases across the globe. The explosive arrival of the seventh cholera pandemic in Latin American in 1991, dramatic epidemics of cholera on the Indian subcontinent and in Southeast Asia due to the newly recognized Vibrio cholerae O139 strain, and the often deadly presence of cholera among populations affected by political and social upheaval in Africa and Eastern Europe are evidence that many countries have failed to adopt effective measures for cholera prevention and control. Foodborne transmission of cholera has been well documented by epidemiologic investigations in nearly every continent, and its interruption is a critical component to any integrated programme for cholera prevention and control. We emphasize clear and effective guidelines for the prevention of foodborne cholera transmission that are drawn from a comprehensive review of relevant epidemiologic and laboratory data. PMID:8905306

  18. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

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

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its...... 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...

  19. NAD metabolism in Vibrio cholerae.

    OpenAIRE

    Foster, J. W.; Brestel, C

    1982-01-01

    Extracts of Vibrio cholerae were assayed for various enzymatic activities associated with pyridine nucleotide cycle metabolism. The activities measured include NAD glycohydrolase, nicotinamide deamidase, nicotinamide mononucleotide deamidase, and nicotinic acid phosphoribosyltransferase. The results obtained demonstrate the existence in V. cholerae of the five-membered pyridine nucleotide cycle and the potential for a four-membered pyridine nucleotide cycle. The data presented also suggest th...

  20. The Enterococcal Cytolysin Synthetase Coevolves with Substrate for Stereoselective Lanthionine Synthesis.

    Science.gov (United States)

    Tang, Weixin; Thibodeaux, Gabrielle N; van der Donk, Wilfred A

    2016-09-16

    Stereochemical control is critical in natural product biosynthesis. For ribosomally synthesized and post-translationally modified peptides (RiPPs), the mechanism(s) by which stereoselectivity is achieved is still poorly understood. In this work, we focused on the stereoselective lanthionine synthesis in lanthipeptides, a major class of RiPPs formed by the addition of Cys residues to dehydroalanine (Dha) or dehydrobutyrine (Dhb). Nonenzymatic cyclization of the small subunit of a virulence lanthipeptide, the enterococcal cytolysin, resulted in the native modified peptide as the major product, suggesting that both regioselectivity and stereoselectivity are inherent to the dehydrated peptide sequence. These results support previous computational studies that a Dhx-Dhx-Xxx-Xxx-Cys motif (Dhx = Dha or Dhb; Xxx = any amino acid except Dha, Dhb, and Cys) preferentially cyclizes by attack on the Re face of Dha or Dhb. Characterization of the stereochemistry of the products formed enzymatically with substrate mutants revealed that the lanthionine synthetase actively reinforces Re face attack. These findings support the hypothesis of substrate-controlled selectivity in lanthionine synthesis but also reveal likely coevolution of substrates and lanthionine synthetases to ensure the stereoselective synthesis of lanthipeptides with defined biological activities. PMID:27348535

  1. 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.

  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. PMID:27487957

  3. Adhesion of Vibrio cholerae to Granular Starches

    OpenAIRE

    Gancz, Hanan; Niderman-Meyer, Orly; Broza, Meir; Kashi, Yechezkel; Shimoni, Eyal

    2005-01-01

    Cholera is a severe diarrheal disease caused by specific serogroups of Vibrio cholerae that are pathogenic to humans. Cholera can become epidemic and deadly without adequate medical care. Appropriate rehydration therapy can reduce the mortality rate from as much as 50% of the affected individuals to

  4. 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.

  5. Arcanolysin is a cholesterol-dependent cytolysin of the human pathogen Arcanobacterium haemolyticum

    Directory of Open Access Journals (Sweden)

    Ratner Adam J

    2011-10-01

    Full Text Available Abstract Background Arcanobacterium haemolyticum is an emerging human pathogen that causes pharyngitis, wound infections, and a variety of occasional invasive diseases. Since its initial discovery in 1946, this Gram positive organism has been known to have hemolytic activity, yet no hemolysin has been previously reported. A. haemolyticum also displays variable hemolytic activity on laboratory blood agar that is dependent upon which species the blood is derived. Results Here we describe a cholesterol-dependent cytolysin (CDC secreted by A. haemolyticum, designated arcanolysin (aln, which is present in all strains (n = 52 tested by DNA dot hybridization. Among the known CDCs, ALN is most closely related to pyolysin (PLO from Trueperella (formerly Arcanobacterium pyogenes. The aln probe, however, did not hybridize to DNA from T. pyogenes. The aln open reading frame has a lower mol %G+C (46.7% than the rest of the A. haemolyticum genome (53.1% and is flanked by two tRNA genes, consistent with probable acquisition by horizontal transfer. The ALN protein (~ 64 kDa contains a predicted signal sequence, a putative PEST sequence, and a variant undecapeptide within domain 4, which is typically important for function of the toxins. The gene encoding ALN was cloned and expressed in Escherichia coli as a functional recombinant toxin. Recombinant ALN had hemolytic activity on erythrocytes and cytolytic activity on cultured cells from human, rabbit, pig and horse origins but was poorly active on ovine, bovine, murine, and canine cells. ALN was less sensitive to inhibition by free cholesterol than perfringolysin O, consistent with the presence of the variant undecapeptide. Conclusions ALN is a newly identified CDC with hemolytic activity and unique properties in the CDC family and may be a virulence determinant for A. haemolyticum.

  6. The cholesterol-dependent cytolysin family of gram-positive bacterial toxins.

    Science.gov (United States)

    Heuck, Alejandro P; Moe, Paul C; Johnson, Benjamin B

    2010-01-01

    The cholesterol-dependent cytolysins (CDCs) are a family of beta-barrel pore-forming toxins secreted by Gram-positive bacteria. These toxins are produced as water-soluble monomeric proteins that after binding to the target cell oligomerize on the membrane surface forming a ring-like pre-pore complex, and finally insert a large beta-barrel into the membrane (about 250 A in diameter). Formation of such a large transmembrane structure requires multiple and coordinated conformational changes. The presence of cholesterol in the target membrane is absolutely required for pore-formation, and therefore it was long thought that cholesterol was the cellular receptor for these toxins. However, not all the CDCs require cholesterol for binding. Intermedilysin, secreted by Streptoccocus intermedius only binds to membranes containing a protein receptor, but forms pores only if the membrane contains sufficient cholesterol. In contrast, perfringolysin O, secreted by Clostridium perfringens, only binds to membranes containing substantial amounts of cholesterol. The mechanisms by which cholesterol regulates the cytolytic activity of the CDCs are not understood at the molecular level. The C-terminus of perfringolysin O is involved in cholesterol recognition, and changes in the conformation of the loops located at the distal tip of this domain affect the toxin-membrane interactions. At the same time, the distribution of cholesterol in the membrane can modulate toxin binding. Recent studies support the concept that there is a dynamic interplay between the cholesterol-binding domain of the CDCs and the excess of cholesterol molecules in the target membrane. PMID:20213558

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Of cabbages and chlorine: cholera in Peru.

    Science.gov (United States)

    1992-07-01

    The low case fatality rates (1%) from the 1991 cholera epidemic in Peru was more a result of including diarrheas of a less virulent etiology than that of cholera. In fact, a study during the early phases of the cholera epidemic in Trujillo, Peru revealed that only 79% of suspected cholera cases were infected with vibrio cholera 01. Further other people contended that the government of Peru did not chlorinate many water supplies because studies by the US Environmental Protection Agency suggested that chlorine increases the cancer risk. It reacts with organic matter to make trihalomethanes. 1 study noted that this risk may explain as many as 700 cases of cancer/year in the US, yet cholera was responsible for nearly 40009 deaths in Latin America the 1st year. Besides in Trujillo, Peru the reason for not chlorinating the water supply was not due to a conscious decision to not do so on the part of the government, but because no funds had been made available to purchase chlorinators and chlorine. This is typical of many towns in developing countries. Further raw fish also played a role in transmitting cholera in Peru. Moreover the study in Trujillo indicated that water stored in containers in the home, and not the water supply, was the most important vehicle of transmission. Nevertheless chlorination of both the water supply and stored water would have prevented cholera transmission. In addition, cabbage irrigated with raw wastewater contributed to cholera transmission in Trujillo. But a concern arises if developing countries follow the advice of WHO of 1st treating wastewater in stabilization ponds. Aquatic blue green algae, other zooplankton, and phytoplankton from a microhabitat suitable for V. cholera. In fact, a study in Peru identified a seasonal pattern of the cholera epidemic with the seasonality of V. cholera non-01 from sewage lagoons in Lima. PMID:1351603

  15. 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.

  16. Vibrio cholerae bacteremia associated with gastrectomy.

    OpenAIRE

    Toeg, A; Berger, S A; Battat, A; Hoffman, M.; Yust, I

    1990-01-01

    Bacteremia due to Vibrio cholerae is rare. Each of 15 cases previously reported in the English language literature occurred in the setting of immune deficiency. We describe an instance of non-serogroup O1 V. cholerae septicemia in an otherwise healthy patient. Susceptibility to such infection may have been enhanced by a prior gastrectomy for duodenal ulcer.

  17. Vibrio cholerae O1 isolated in Kenya.

    OpenAIRE

    Iwanaga, M; Mori, K.; Kaviti, J N

    1982-01-01

    Biological and serological analyses of 272 isolates of Vibrio cholerae O1 from six epidemics and from a few sporadic cases in Kenya were carried out. All of the isolates were identified as V. cholerae biotype E1 Tor, and 210 out of 272 isolates were hemolytic as examined by Feeley's method.

  18. [Various aspects of the seventh cholera pandemic].

    Science.gov (United States)

    Ladnyĭ, I D

    1976-07-01

    Problems on epidemiological surveillance over cholera are elucidated; recommendations elaborated at the meeting in Madrid in 1975 are given. Data on cholera morbidity on different continent in 1961-1975, with indication of the number of countries which sent their reports to the WHO, are presented. PMID:1007738

  19. Draft Genome Sequence of Environmental Vibrio cholerae 2012EL-1759 with Similarities to the V. cholerae O1 Classical Biotype

    OpenAIRE

    Katz, Lee S.; Turnsek, Maryann; Kahler, Amy; Hill, Vincent R.; Boyd, E. Fidelma; Tarr, Cheryl L.

    2014-01-01

    Vibrio cholerae 2012EL-1759 is an environmental isolate from Haiti that was recovered in 2012 during a cholera outbreak. The genomic backbone is similar to that of the prototypical V. cholerae O1 classical biotype strain O395, and it carries the Vibrio pathogenicity islands (VPI-1 and VPI-2) and a cholera toxin (CTX) prephage.

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

    OpenAIRE

    StefanPukatzki; DanieleProvenzano

    2013-01-01

    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 ...

  1. Risk factors for cholera transmission in Haiti during inter-peak periods: insights to improve current control strategies from two case-control studies.

    Science.gov (United States)

    Grandesso, F; Allan, M; Jean-Simon, P S J; Boncy, J; Blake, A; Pierre, R; Alberti, K P; Munger, A; Elder, G; Olson, D; Porten, K; Luquero, F J

    2014-08-01

    Two community-based density case-control studies were performed to assess risk factors for cholera transmission during inter-peak periods of the ongoing epidemic in two Haitian urban settings, Gonaives and Carrefour. The strongest associations were: close contact with cholera patients (sharing latrines, visiting cholera patients, helping someone with diarrhoea), eating food from street vendors and washing dishes with untreated water. Protective factors were: drinking chlorinated water, receiving prevention messages via television, church or training sessions, and high household socioeconomic level. These findings suggest that, in addition to contaminated water, factors related to direct and indirect inter-human contact play an important role in cholera transmission during inter-peak periods. In order to reduce cholera transmission in Haiti intensive preventive measures such as hygiene promotion and awareness campaigns should be implemented during inter-peak lulls, when prevention activities are typically scaled back. PMID:24112364

  2. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

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

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its....... 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...

  3. [Cholera in a district of Peru].

    Science.gov (United States)

    Pérez Rodríguez, A E; Monté Boada, R; de la Vega Díaz, J E; Molina, R; García Gómez, V; Arca González, J M

    1996-01-01

    Taking to consideration the low report of cholera patients and with the main knowing the reality about the introduction of Vibrio cholerae (V. cholerae) in Peru, a sample of 101 cases with acute diarrheal disease (ADD) was taken at the Distrito Villa El Salvador. They were selected by a systematic randomized sampling defined for each health care unit in the District, according to the daily average occurrence of ADD cases attended a week before the beginning of the study. All of them took part in a epidemiological survey. A sample was taken by rectal swab in order to isolate V. cholerae. 53 positive cases were found (52.2% and a confidence interval from 42.29 to 62.5%) with significant differences (p < 0.01) between the frequency in adults (67.3%) and children (34.8%). V. cholerae was isolated only in 13 (61.9%) of the 21 cases who had contact with cholera patients, for a relative risk of 1.24 (0.83 < RR < 1.85). A high positivity was also found, 21 cases (72.4%) among those who had raw food. A significant difference (p < 0.01) was observed in connection with those who had cooked food. In the multivariate logistic regression analysis it was only found a significant relationship with age and with the ingestion of raw food as regards the occurrence of cholera. PMID:9805053

  4. Promotion

    OpenAIRE

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed.

  5. Production of Vibrio cholerae accessory cholera enterotoxin (Ace) in the yeast Pichia pastoris.

    OpenAIRE

    Trucksis, M; Conn, T L; Fasano, A; Kaper, J B

    1997-01-01

    Accessory cholera enterotoxin (Ace) is a recently identified toxin of Vibrio cholerae. Preliminary studies using crude toxin extracts in animal models indicate that Ace increases transcellular ion transport, which is proposed to contribute to diarrhea in cholera. The lack of purified toxin has hindered elucidation of the mechanism of action of Ace. In this study, ace was cloned and was expressed in and secreted by the methylotrophic yeast Pichia pastoris. Secreted toxin constituted 50% of the...

  6. 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,...

  7. 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.

  8. EFFECT OF AGGREGATION ON VIBRIO CHOLERA 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. uring the course of investigating a major waterborne V. Cholerae outbreak in Peru, U.S. EPA investigat...

  9. FOWL CHOLERA IN A BREEDER FLOCK

    OpenAIRE

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

    2003-01-01

    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. β-Hemolysin/cytolysin of Group B Streptococcus enhances host inflammation but is dispensable for establishment of urinary tract infection.

    Directory of Open Access Journals (Sweden)

    Ritwij Kulkarni

    Full Text Available Group B Streptococcus (GBS; Streptococcus agalactiae is a major human pathogen that disproportionately affects neonates and women in the peripartum period and is an emerging cause of infection in older adults. The primary toxin of GBS, β-hemolysin/cytolysin (βH/C, has a well-defined role in the pathogenesis of invasive disease, but its role in urinary tract infection (UTI is unknown. Using both in vitro and in vivo models, we analyzed the importance of βH/C in GBS uropathogenesis. There were no significant differences in bacterial density from the bladders or kidneys from mice infected with wild-type or isogenic βH/C-deficient GBS, and competitive indices from co-infection experiments were near 1. Thus, βH/C is dispensable for the establishment of GBS-UTI. However, βH/C-sufficient GBS induced a more robust proinflammatory cytokine response in cultured bladder epithelial cells and in the urinary tracts of infected mice. Given the near ubiquity of βH/C-expressing strains in epidemiologic studies and the importance of local inflammation in dictating outcomes and sequelae of UTI, we hypothesize that βH/C-driven inflammatory signaling may be important in the clinical course of GBS-UTI.

  11. 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.

  12. Cellular Functions and X-ray Structure of Anthrolysin O, a Cholesterol-dependent Cytolysin Secreted by Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Bourdeau, Raymond W.; Malito, Enrico; Chenal, Alexandre; Bishop, Brian L.; Musch, Mark W.; Villereal, Mitch L.; Chang, Eugene B.; Mosser, Elise M.; Rest, Richard F.; Tang, Wei-Jen; (CNRS-UMR); (Drexel-MED); (UC)

    2009-06-02

    Anthrolysin O (ALO) is a pore-forming, cholesterol-dependent cytolysin (CDC) secreted by Bacillus anthracis, the etiologic agent for anthrax. Growing evidence suggests the involvement of ALO in anthrax pathogenesis. Here, we show that the apical application of ALO decreases the barrier function of human polarized epithelial cells as well as increases intracellular calcium and the internalization of the tight junction protein occludin. Using pharmacological agents, we also found that barrier function disruption requires increased intracellular calcium and protein degradation. We also report a crystal structure of the soluble state of ALO. Based on our analytical ultracentrifugation and light scattering studies, ALO exists as a monomer. Our ALO structure provides the molecular basis as to how ALO is locked in a monomeric state, in contrast to other CDCs that undergo antiparallel dimerization or higher order oligomerization in solution. ALO has four domains and is globally similar to perfringolysin O (PFO) and intermedilysin (ILY), yet the highly conserved undecapeptide region in domain 4 (D4) adopts a completely different conformation in all three CDCs. Consistent with the differences within D4 and at the D2-D4 interface, we found that ALO D4 plays a key role in affecting the barrier function of C2BBE cells, whereas PFO domain 4 cannot substitute for this role. Novel structural elements and unique cellular functions of ALO revealed by our studies provide new insight into the molecular basis for the diverse nature of the CDC family.

  13. 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

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

    Science.gov (United States)

    Rebaudet, Stanislas; Mengel, Martin A; Koivogui, Lamine; Moore, Sandra; Mutreja, Ankur; Kande, Yacouba; Yattara, Ousmane; Sarr Keita, Véronique; Njanpop-Lafourcade, Berthe-Marie; Fournier, Pierre-Edouard; Garnotel, Eric; Keita, Sakoba; Piarroux, Renaud

    2014-06-01

    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 disease control

  15. 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

  16. Enhancement of enterotoxin production by carbon dioxide in Vibrio cholerae.

    OpenAIRE

    Shimamura, T; Watanabe, S; Sasaki, S.

    1985-01-01

    We found that Vibrio cholerae 569B produced much more cholera enterotoxin in the presence of added carbon dioxide than in its absence. An atmosphere of 10% carbon dioxide was optimal for maximal enterotoxin production.

  17. Phylogeny of Vibrio cholerae Based on recA Sequence

    OpenAIRE

    Stine, O. Colin; Sozhamannan, Shanmuga; Gou, Qing; Zheng, Siqen; Morris, J. Glenn; Johnson, Judith A.

    2000-01-01

    We sequenced a 705-bp fragment of the recA gene from 113 Vibrio cholerae strains and closely related species. One hundred eighty-seven nucleotides were phylogenetically informative, 55 were phylogenetically uninformative, and 463 were invariant. Not unexpectedly, Vibrio parahaemolyticus and Vibrio vulnificus strains formed out-groups; we also identified isolates which resembled V. cholerae biochemically but which did not cluster with V. cholerae. In many instances, V. cholerae serogroup desig...

  18. 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.

  19. Highly Potent, Chemically Stable Quorum Sensing Agonists for Vibrio Cholerae

    OpenAIRE

    Perez, Lark J; Karagounis, Theodora K.; Hurley, Amanda; Bassler, Bonnie L.; Semmelhack, Martin F.

    2013-01-01

    In the Vibrio cholerae pathogen, initiation of bacterial quorum sensing pathways serves to suppress virulence. We describe herein a potent and chemically stable small molecule agonist of V. cholerae quorum sensing, which was identified through rational drug design based on the native quorum sensing signal. This novel agonist may serve as a useful lead compound for the control of virulence in V. cholerae.

  20. Phage specific for Vibrio cholerae O139 Bengal.

    OpenAIRE

    Albert, M J; Bhuiyan, N A; Rahman, A; Ghosh, A. N.; Hultenby, K; Weintraub, A; Nahar, S; Kibriya, A K; Ansaruzzaman, M; Shimada, T

    1996-01-01

    From the stool of a Vibrio cholerae O139 Bengal-infected patient, a phage that specifically lysed capsulated V. cholerae O139 strains only was isolated. The phage is useful for the confirmatory diagnosis of V. cholerae O139 infection and for the differentiation of variants that lack the capsule.

  1. 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...

  2. 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.

  3. 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.

  4. 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...

  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. Pulmonary Cholera Due to Infection with a Non-O1 Vibrio cholerae Strain

    OpenAIRE

    Shannon, Jack D.; Kimbrough, Robert C.

    2006-01-01

    We present 2 cases of primary pulmonary non-O1 Vibrio cholerae infection. We believe that these are the first documented cases of primary pulmonary infection due to this organism from a freshwater source.

  7. The case for reactive mass oral cholera vaccinations.

    Directory of Open Access Journals (Sweden)

    Rita Reyburn

    Full Text Available INTRODUCTION: The outbreak of cholera in Zimbabwe intensified interest in the control and prevention of cholera. While there is agreement that safe water, sanitation, and personal hygiene are ideal for the long term control of cholera, there is controversy about the role of newer approaches such as oral cholera vaccines (OCVs. In October 2009 the Strategic Advisory Group of Experts advised the World Health Organization to consider reactive vaccination campaigns in response to large cholera outbreaks. To evaluate the potential benefit of this pivotal change in WHO policy, we used existing data from cholera outbreaks to simulate the number of cholera cases preventable by reactive mass vaccination. METHODS: Datasets of cholera outbreaks from three sites with varying cholera endemicity--Zimbabwe, Kolkata (India, and Zanzibar (Tanzania--were analysed to estimate the number of cholera cases preventable under differing response times, vaccine coverage, and vaccine doses. FINDINGS: The large cholera outbreak in Zimbabwe started in mid August 2008 and by July 2009, 98,591 cholera cases had been reported with 4,288 deaths attributed to cholera. If a rapid response had taken place and half of the population had been vaccinated once the first 400 cases had occurred, as many as 34,900 (40% cholera cases and 1,695 deaths (40% could have been prevented. In the sites with endemic cholera, Kolkata and Zanzibar, a significant number of cases could have been prevented but the impact would have been less dramatic. A brisk response is required for outbreaks with the majority of cases occurring during the early weeks. Even a delayed response can save a substantial number of cases and deaths in long, drawn-out outbreaks. If circumstances prevent a rapid response there are good reasons to roll out cholera mass vaccination campaigns well into the outbreak. Once a substantial proportion of a population is vaccinated, outbreaks in subsequent years may be reduced if not

  8. 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.

  9. 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.

  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. Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates.

    Directory of Open Access Journals (Sweden)

    Sandra Moore

    Full Text Available Since cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hotspots including the African Great Lakes Region and West Africa.In this study, we applied MLVA (Multi-Locus Variable Number Tandem Repeat Analysis typing of 337 Vibrio cholerae isolates from recent cholera epidemics in the Democratic Republic of the Congo (DRC, Zambia, Guinea and Togo. We aimed to assess the relationship between outbreaks. Applying this method, we identified 89 unique MLVA haplotypes across our isolate collection. MLVA typing revealed the short-term divergence and microevolution of these Vibrio cholerae populations to provide insight into the dynamics of cholera outbreaks in each country. Our analyses also revealed strong geographical clustering. Isolates from the African Great Lakes Region (DRC and Zambia formed a closely related group, while West African isolates (Togo and Guinea constituted a separate cluster. At a country-level scale our analyses revealed several distinct MLVA groups, most notably DRC 2011/2012, DRC 2009, Zambia 2012 and Guinea 2012. We also found that certain MLVA types collected in the DRC persisted in the country for several years, occasionally giving rise to expansive epidemics. Finally, we found that the six environmental isolates in our panel were unrelated to the epidemic isolates.To effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.

  12. Polymerase chain reaction for detection of the cholera enterotoxin operon of Vibrio cholerae.

    OpenAIRE

    1991-01-01

    We report a set of oligonucleotide primers and amplification conditions for the polymerase chain reaction to detect the ctx operon of Vibrio cholerae. The results of this assay on strains of V. cholerae and related organisms were identical with those obtained by the DNA colony hybridization test with the polynucleotide probe. The detection limit of this system was 1 pg of chromosomal DNA or broth culture containing three viable cells. The polymerase chain reaction method could directly detect...

  13. 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...

  14. 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.

  15. 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.

  16. 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).

  17. 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.

  18. 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

  19. Review of oral cholera vaccines: efficacy in young children

    Directory of Open Access Journals (Sweden)

    Masuet Aumatell C

    2011-09-01

    Full Text Available Cristina Masuet Aumatell1, JM Ramon Torrell1, Jane N Zuckerman21International Health Centre, Preventive Medicine Department, Bellvitge Hospital, L'Hospitalet de Llobregat, Barcelona, Spain; 2World Health Organization Collaborating Centre for Reference, Research and Training in Travel Medicine, University College London Medical School, London, UKBackground: Young children are one of the most vulnerable groups who may be infected with cholera. The following literature review of the efficacy of the currently available cholera vaccines provides a clear evidence base for the clinical administration of cholera vaccine, particularly in an epidemic situation.Aim: To assess the efficacy of oral cholera vaccines in preventing cases of cholera in young children.Methods: A systematic literature review was undertaken for the period 1983 to 2011 using PubMed and the search terms “oral cholera vaccines,” “children,” and “efficacy,” limited to “clinical trials” and “human studies”.Results: Oral cholera vaccine provides an acceptable level of protection in young children, with the level of protection being greater at 12 or 24 months following immunization.Conclusions: Children exposed to a potential risk of cholera are recommended to be vaccinated with an oral cholera vaccine, irrespective of whether its constituents include the B subunit.Keywords: efficacy, oral cholera vaccine, children

  20. 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

  1. Genome Sequence of Vibrio cholerae G4222, a South African Clinical Isolate

    OpenAIRE

    le Roux, Wouter J.; Chan, Wai Yin; De Maayer, Pieter; Venter, Stephanus N.

    2013-01-01

    Vibrio cholerae, a Gram-negative pathogen autochthonous to the aquatic environment, is the causative agent of cholera. Here, we report the complete genome sequence of V. cholerae G4222, a clinical isolate from South Africa.

  2. 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...

  3. 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.

  4. [The role of food in cholera transmission].

    Science.gov (United States)

    Dobosch, D; Gomez Zavaglia, A; Kuljich, A

    1995-01-01

    The spreading of cholera, from Peru to other Latinoamerican countries in 1991, raised questions regarding food safety, food transportation and handling. Control, prevention and risks implied in food import-export were also matters of concern. We deemed it interesting to determine the viability of Vibrio cholerae in wide consumption food locally. Selected food had different intrinsic characteristics such as: acidity (pH), water activity (aw), chemical composition, indigenous flora and other biologic and physic parameters. Twenty food products were contaminated with V. cholerae O1, Ogawa, toxigenic and not toxigenic strains: yoghurt, cream cheese, apricot marmelade, hip rose marmelade, mayonnaise, italian pasta for "empanadas", "dulce de leche", meat sausage, meat and spinach ravioli, margarine, milk dessert (made with cocoa, milk confiture, starch and additives), lettuce, tuna fish, ricotta and sterilized milk. Table I shows the viability of V. cholerae in tested foods, its pH and the reasons why the experiments were ended: 75% of the products studied could tolerate the development of the microorganism for a period ranging from one day (pasta for "empanadas") to ninety days (sterilized milk). Foods with acredity higher than pH 5.5 did not favor the growth of Vibrio. When pH was neutral or slightly acid, viability persisted independently from aw, microbial antagonisms and other physic, chemical or biologic parameters. Nevertheless, other factors such as: surface adherence, amino acids, magnesium and environmental influences not yet well determined, could eventually modify the persistence of V. cholerae in food. According to this study, most food products could tolerate growth and persistence of the infectant agent, up for three months in some cases.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7565031

  5. 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

  6. The role of Vibrio cholerae genotyping in Africa.

    Science.gov (United States)

    De, Rituparna; Ghosh, Jayeeta Banerjee; Sen Gupta, Sourav; Takeda, Yoshifumi; Nair, G Balakrish

    2013-11-01

    Toxigenic Vibrio cholerae, the causative agent of the disease cholera, is prevalent in the African continent from the 1970s when the seventh pandemic spread from Asia to Africa. In the past decade, cholera has caused devastating outbreaks in much of Africa, illustrated by the recent cholera epidemics in Zimbabwe and regions of central Africa. Given the extent of cholera in Africa, a robust and efficient surveillance system should be in place to prevent and control the disease in this continent. Such a surveillance system would be greatly bolstered by use of molecular typing techniques to identify genetic subtypes. In this review, we highlight the role that modern molecular typing techniques can play in tracking and aborting the spread of cholera. PMID:24101642

  7. 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.

  8. 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.

  9. A localized outbreak of cholera due to vibrio cholerae, ogawa resistant to tetracyclines

    International Nuclear Information System (INIS)

    To study the clinical and laboratory parameters of a localized Cholera outbreak and determine the sensitivity pattern of the subtype involved. Study Design: A descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore. Duration of Study: Two weeks. Patients and Methods: The study is about a localized outbreak of cholera in a group of soldiers, who consumed water from a single contaminated source of water. We are presenting here an account of the clinical and laboratory parameters of 39 hospitalized cases of cholera, who presented with profuse watery diarrhoea and vomiting. There vital signs, hydration status and systemic examination findings were recorded. Stool samples were sent for routine and microscopic examination and bacteriological culture. Blood samples were taken for complete blood count, serum sodium, potassium, urea and creatinine examination. SPSS 18 was used for statistical analysis of the results. Results: The average age of thirty nine men studied in this outbreak was 24.9 ± 6.9 years. There was no statistically significant difference between confirmed and suspected cholera cases on descriptive analysis of the clinical and laboratory parameters. Majority of patients showed pre-renal azotemia which improved within 48 to 72 hours of hospitalization. Stool cultures isolated Vibrio cholerae, subtype Ogawa, which was resistant to tetracyclines, cotrimoxazole and nalidixic acid but sensitive to fluoroquinolones and third generation cephalosporins. The outbreak was controlled when the contaminated water source was sealed and rectified. Conclusion: Multiple drug resistance strains of Vibrio cholera are causing large outbreaks which should be controlled by prevention of the disease and avoiding inappropriate use of antibiotics. (author)

  10. 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

  11. 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

  12. 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. PMID:27555841

  13. 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. PMID:27555841

  14. Vibrio cholerae O139 in Thailand in 1994.

    OpenAIRE

    Bodhidatta, L.; Echeverria, P; Hoge, C W; Pitarangsi, C; Serichantalergs, O; Henprasert-Tae, N.; Harikul, S.; Kitpoka, P.

    1995-01-01

    Vibrio cholerae O139 first appeared in India and Bangladesh in 1992. Surveillance for O139 was started at three hospitals in Thailand in 1993. By 1994 all three hospitals surveyed in Thailand had experienced an increase in Vibrio cholerae O139 infections.

  15. Synthesis of protein in intestinal cells exposed to cholera toxin

    International Nuclear Information System (INIS)

    The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells and Chinese hamster ovary cells exposed to cholera toxin. An increase in [3H] leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of [35S] methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed

  16. Nontoxigenic Vibrio cholerae Septicemia in an Immunocompromised Patient

    OpenAIRE

    Kamran Kadkhoda; Heather Adam; Gilmour, Matthew W.; Hammond, Gregory W.

    2012-01-01

    We report a recent case of non-O1, non-O139, nontoxigenic Vibrio cholerae septicemia in a post-liver-transplant immunocompromised patient associated with prior seafood consumption. Non-O1, non-O139 V. cholerae strains have been reported in several cases of extraintestinal infections and seem to be emerging infectious agents especially in patients with immunocompromising conditions.

  17. 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

  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. 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.

  20. 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...

  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. 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.

  3. 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.

  4. 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.

  5. Cloning of Vibrio cholerae outer membrane protein W in Pichia pastoris.

    Directory of Open Access Journals (Sweden)

    Javad Alizadeh

    2013-09-01

    Full Text Available The outer membrane protein W (ompW of Vibrio cholerae is involved in stimulating the immune response via induction of protective immunity. It also plays an important role in bacterial pathogenesis by increasing the adaptability of pathogenic strains. In this study we aimed to clone V. cholerae ompW gene in the strain X-33 of Pichia pastoris.A gene encoding ompW was cloned into the Ppicza vector downstream of alcohol oxidase promoter. Then recombinant vector was transformed into the genome of the strain X-33 of P. pastoris. After growth of zeocin-resistant transformants, clones were selected and subsequently confirmed for cloning by PCR enzymatic digestion and sequencing.PCR, enzymatic digestion and sequencing showed that the ompW gene was correctly cloned into P. pastoris genome.Results of our study showed that the methylotrophic yeast P. pastoris can be considered as an appropriate host instead of mammalian and prokaryotic systems for cloning of ompW. As far as data show, this is the first time that ompW of V. cholera is cloned into the methylotrophic P. pastoris.

  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. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Farhana, Israt; 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]....

  8. 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.

  9. 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. PMID:25621620

  10. 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. PMID:27247094

  11. Genome Sequence and Comparative Genomics Analysis of a Vibrio cholerae O1 Strain Isolated from a Cholera Patient in Malaysia

    Science.gov (United States)

    Osama, Abdulrazak; Gan, Han Ming; Teh, Cindy Shuan Ju; Yap, Kien-Pong

    2012-01-01

    The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223. PMID:23209200

  12. Genome Sequence and Comparative Genomics Analysis of a Vibrio cholerae O1 Strain Isolated from a Cholera Patient in Malaysia

    OpenAIRE

    Osama, Abdulrazak; Gan, Han Ming; Teh, Cindy Shuan Ju; Yap, Kien-Pong; Thong, Kwai-Lin

    2012-01-01

    The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223.

  13. Spatially selective colonization of the arthropod intestine through activation of Vibrio cholerae biofilm formation

    OpenAIRE

    Purdy, Alexandra E.; Watnick, Paula I.

    2011-01-01

    Vibrio cholerae is an estuarine bacterium and the human pathogen responsible for the diarrheal disease cholera. In the environment, arthropods are proposed to be carriers and reservoirs of V. cholerae. However, the molecular basis of the association between V. cholerae and viable arthropods has not been elucidated previously. Here, we show that the V. cholerae Vibrio polysaccharide (VPS)-dependent biofilm is highly activated upon entry into the arthropod intestine and is specifically required...

  14. A Metalloprotease Secreted by the Type II Secretion System Links Vibrio cholerae with Collagen

    OpenAIRE

    Park, Bo R.; Ryszard A Zielke; Wierzbicki, Igor H.; Mitchell, Kristie C.; Withey, Jeffrey H.; Sikora, Aleksandra E.

    2015-01-01

    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 m...

  15. 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.

  16. 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.

  17. 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. PMID:27599865

  18. 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.

  19. 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.

  20. 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.

  1. Cholera outbreak in Senegal in 2005: was climate a factor?

    Directory of Open Access Journals (Sweden)

    Guillaume Constantin de Magny

    Full Text Available Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region.

  2. Cholera Outbreak in Senegal in 2005: Was Climate a Factor?

    Science.gov (United States)

    Constantin de Magny, Guillaume; Thiaw, Wassila; Kumar, Vadlamani; Manga, Noël M.; Diop, Bernard M.; Gueye, Lamine; Kamara, Mamina; Roche, Benjamin; Murtugudde, Raghu; Colwell, Rita R.

    2012-01-01

    Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST) gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region. PMID:22952995

  3. 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. PMID:27430513

  4. Predictive modeling of cholera using GRACE and TRMM satellite data

    Science.gov (United States)

    Jutla, A.; Akanda, A. S. S.; Colwell, R. R.

    2015-12-01

    Cholera outbreaks can be classified in three forms- epidemic (sudden or seasonal outbreaks), endemic (recurrence and persistence of the disease for several consecutive years) and mixed-mode endemic (combination of certain epidemic and endemic conditions) with significant spatial and temporal heterogeneity. Endemic cholera is related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. With more than a decade of terrestrial water storage (TWS) data obtained from Gravity Recovery and Climate Experiment (GRACE), understanding dynamics of river discharge is now feasible. We explored lead-lag relationships between TWS in the Ganges-Brahmaputra-Meghna (GBM) basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during the spring and autumn season, two separate models, between TWS and disease time series (2002 to 2010) were developed. TWS, hence water availability, showed an asymmetrical, strong association with spring (τ=-0.53; p<0.001) and autumn (τ=0.45; p<0.001) cholera prevalence up to five to six months in advance. One unit (cm of water) decrease in water availability in the basin increased odds of above normal cholera by 24% [confidence interval (CI) 20-31%; p<0.05] in the spring season, while an increase in regional water by one unit, through floods, increased odds of above average cholera in the autumn by 29% [CI:22-33%; p<0.05]. Epidemic cholera is related with warm temperatures and heavy rainfall. Using TRMM data for several locations in Asia and Africa, probability of cholera increases 18% [CI:15-23%; p<0.05] after heavy precipitation resulted in a societal conditions where access to safe water and sanitation was disrupted. Results from mechanistic modeling framework using systems approach that include satellite based hydroclimatic information with tradition disease transmission models will also be presented.

  5. 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.

  6. Cholera outbreak caused by drug resistant Vibrio cholerae serogroup O1 biotype ElTor serotype Ogawa in Nepal; a cross-sectional study

    OpenAIRE

    Gupta, Pappu Kumar; Pant, Narayan Dutt; Bhandari, Ramkrishna; Shrestha, Padma

    2016-01-01

    Background Cholera is a major cause of mortality and morbidity in underdeveloped countries including Nepal. Recently drug resistance in Vibrio cholerae has become a serious problem mainly in developing countries. The main objectives of our study were to investigate the occurrence of Vibrio cholerae in stool samples from patients with watery diarrhea and to determine the antimicrobial susceptibility patterns of V. cholerae isolates. Methods A total of 116 stool samples from patients suffering ...

  7. New developments in the understanding of cholera.

    Science.gov (United States)

    Butler, T

    2001-08-01

    Recent advances in prevention and treatment of cholera have occurred in the areas of vaccine testing, modifications of oral-rehydration solutions (ORS), and antimicrobial treatment. Oral vaccines consisting of killed whole bacterial cells (WC) with and without the B-subunit of cholera toxin (BS) were shown to be effective in large trials in Bangladesh, Peru, and Vietnam. However, the trials did not resolve whether two or three doses of vaccine are required and whether BS adds significantly to the immune protection of WC. Live, attenuated bacterial vaccines that are immunogenic and have been shown protective in human volunteer studies are candidates for future field trials. Rehydration of patients is a life- saving effort. The best ORS contains rice powder in place of glucose, and solutions with reduced osmolarity (245 mOsm/L, sodium 75 mEq/L) are as effective as standard ORS. Ciprofloxacin in a single dose is effective in adults, and erythromycin or ampicillin in multiple doses is effective in children. PMID:11470000

  8. Genetic traits of Vibrio cholerae O1 Haitian isolates that are absent in contemporary strains from Kolkata, India.

    Directory of Open Access Journals (Sweden)

    Priyanka Ghosh

    Full Text Available The world's worst cholera epidemic in Haiti (2010 coerced to trace the origin and dissemination of the causative agent Vibrio cholerae O1 for proper management of cholera. Sequence analysis of the Haitian strain showed several variations in the genes encoding cholera toxin B subunit (ctxB; toxin-co-regulated pilus (tcpA, repeat in toxins (rtxA, quinolone resistance-determining region (QRDR of gyrase A (gyrA, rstB of RS element along with the change in the number of repeat sequences at the promoter region of ctxAB. Our earlier studies showed that variant tcpA (tcpA CIRS and ctxB (ctxB7 first appeared in Kolkata during 2003 and 2006, respectively. The present study revealed that a variant rtxA was first isolated in Kolkata during 2004 and probably formed the genetic background for the emergence of the ctxB7 allele as we were unable to detect a single strain with the combination of El Tor rtxA and ctxB7. The variant gyrA was first time detected in Kolkata during 1994. The Kolkata strains contained four heptad repeats (TTTTGAT in their CT promoter regions whereas Haitian strains carried 5 heptad repeats. Haitian strains had 3 nucleotide deletions at the rstB gene, which is a unique feature of the classical biotype strains. But the Kolkata strains did not have such deletion mutations in the rstB. Our study demonstrated the existence of some Haitian genetic traits in Kolkata isolates along with the dissimilarities in genomic content with respect to rstB and ctxAB promoter region. Finally, we conclude that Haitian variant strain may be evolved due to sequential event in the Indian subcontinent strain with some cryptic modification in the genome.

  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. Pathogenesis of Streptococcus urinary tract infection depends on bacterial strain and β-hemolysin/cytolysin that mediates cytotoxicity, cytokine synthesis, inflammation and virulence.

    Science.gov (United States)

    Leclercq, Sophie Y; Sullivan, Matthew J; Ipe, Deepak S; Smith, Joshua P; Cripps, Allan W; Ulett, Glen C

    2016-01-01

    Streptococcus agalactiae can cause urinary tract infection (UTI) including cystitis and asymptomatic bacteriuria (ABU). The early host-pathogen interactions that occur during S. agalactiae UTI and subsequent mechanisms of disease pathogenesis are poorly defined. Here, we define the early interactions between human bladder urothelial cells, monocyte-derived macrophages, and mouse bladder using uropathogenic S. agalactiae (UPSA) 807 and ABU-causing S. agalactiae (ABSA) 834 strains. UPSA 807 adhered, invaded and killed bladder urothelial cells more efficiently compared to ABSA 834 via mechanisms including low-level caspase-3 activation, and cytolysis, according to lactate dehydrogenase release measures and cell viability. Severe UPSA 807-induced cytotoxicity was mediated entirely by the bacterial β-hemolysin/cytolysin (β-H/C) because an β-H/C-deficient UPSA 807 isogenic mutant, UPSA 807ΔcylE, was not cytotoxic in vitro; the mutant was also significantly attenuated for colonization in the bladder in vivo. Analysis of infection-induced cytokines, including IL-8, IL-1β, IL-6 and TNF-α in vitro and in vivo revealed that cytokine and chemokine responses were dependent on expression of β-H/C that also elicited severe bladder neutrophilia. Thus, virulence of UPSA 807 encompasses adhesion to, invasion of and killing of bladder cells, pro-inflammatory cytokine/chemokine responses that elicit neutrophil infiltration, and β-H/C-mediated subversion of innate immune-mediated bacterial clearance from the bladder. PMID:27383371

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

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    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.

  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. 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.

  15. Cholera in Ecuador: Current relevance of past lessons learnt

    OpenAIRE

    S S Malavade; A Narvaez; A. Mitra; Ochoa, T; Naik, E.; Sharma, M.; S Galwankar; M D Breglia; Izurieta, R

    2011-01-01

    This report analyses the trends in the cholera epidemic that hit Ecuador in 1991. The study is based on personal experiences and analysis of epidemiological databases from the Ministry of Public Health of Ecuador. The number of cases and initial attack rates in an immunologically naive population are described by province. An analysis of the Andean and coastal cholera patterns of transmission are described along with its associated risk factors. The logistical, environmental, and socio-cultur...

  16. Third-generation cephalosporin-resistant Vibrio cholerae, India.

    Science.gov (United States)

    Mandal, Jharna; Sangeetha, Vilwanathan; Ganesan, Vithiya; Parveen, Mohamudha; Preethi, Venkatesan; Harish, Belgode Narasimha; Srinivasan, Sampath; Parija, Subhash Chandra

    2012-08-01

    Vibrio cholerae resistance to third-generation cephalosporins is rarely reported. We detected a strain that was negative for extended-spectrum β-lactamase and positive for the AmpC disk test, modified Hodge test, and EDTA disk synergy test and harbored the blaDHA-1 and blaNDM-1 genes. The antimicrobial drug susceptibility profile of V. cholerae should be monitored. PMID:22840562

  17. 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. PMID:24481887

  18. Warming Oceans, Phytoplankton, and River Discharge: Implications for Cholera Outbreaks

    OpenAIRE

    Jutla, Antarpreet S; Akanda, Ali S.; Griffiths, Jeffrey K; Colwell, Rita; Islam, Shafiqul

    2011-01-01

    Phytoplankton abundance is inversely related to sea surface temperature (SST). However, a positive relationship is observed between SST and phytoplankton abundance in coastal waters of Bay of Bengal. This has led to an assertion that in a warming climate, rise in SST may increase phytoplankton blooms and, therefore, cholera outbreaks. Here, we explain why a positive SST-phytoplankton relationship exists in the Bay of Bengal and the implications of such a relationship on cholera dynamics. We f...

  19. 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.

  20. Molecular epidemiology of Vibrio cholerae O1 isolated in Nepal by southern hybridization with a cholera toxin gene probe.

    Science.gov (United States)

    Yamamoto, K; Shrestha, J; Iida, T; Yoh, M; Honda, T

    1995-06-01

    A cholera epidemic broke out in 1992 due to Vibrio cholerae O1 biotype El Tor in the eastern and southern belt of Nepal mainly among the Bhutanese refugees. Restriction fragment profiles (RFP) of DNA fragments of V. cholerae O1 isolates hybridized with an enzyme-labelled oligonucleotide probe for cholera toxin gene (ctx) by Southern Hybridization were compared. The probe hybridized with the 13- and 8-kb fragments of PstI-digested total DNA in all isolates observed in the epidemic. This RFP in the Nepalese strain was not observed in the strains isolated during other epidemics but was observed in the strains isolated from the exported marine products from Taiwan and Thailand. PMID:7594311

  1. Epidemiology, determinants and dynamics of cholera in pakistan: gaps and prospects for future research

    International Nuclear Information System (INIS)

    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. (author)

  2. 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.

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

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    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

  4. 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. PMID:26735874

  5. Cholera at the Crossroads: The Association Between Endemic Cholera and National Access to Improved Water Sources and Sanitation

    OpenAIRE

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

    2014-01-01

    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 < 0.001. Using a value of 250 for annual cases reported in 3 of 5 years, a national water access level of...

  6. 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.

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

    Science.gov (United States)

    Boucher, Yan

    2016-01-01

    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. PMID:27143391

  8. 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.

  9. 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.

  10. FK phage for differentiating the classical and El T or groups of Vibrio cholerae.

    OpenAIRE

    Takeya, K; Otohuji, T; Tokiwa, H

    1981-01-01

    A new vibrio-infecting phage (FK phage) isolated from sewage lysed all strains of Vibrio cholerae biovar cholerae, whereas all strains of V. cholerae biovar El Tor were resistant to it. FK phage was entirely different from Mukerjee group IV phage in morphology and antigenicity. In addition to group IV phage, the use of FK phage will be useful in the examination and typing of V. cholerae.

  11. 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.

  12. 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.

  13. Evaluation in mice of a conjugate vaccine for cholera made from Vibrio cholerae O1 (Ogawa O-specific polysaccharide.

    Directory of Open Access Journals (Sweden)

    Mohammad Murshid Alam

    2014-02-01

    Full Text Available BACKGROUND: Protective immunity against cholera is serogroup specific. Serogroup specificity in Vibrio cholerae is determined by the O-specific polysaccharide (OSP of lipopolysaccharide (LPS. Generally, polysaccharides are poorly immunogenic, especially in young children. METHODOLOGY: Here we report the evaluation in mice of a conjugate vaccine for cholera (OSP:TThc made from V. cholerae O1 Ogawa O-Specific Polysaccharide-core (OSP and recombinant tetanus toxoid heavy chain fragment (TThc. We immunized mice intramuscularly on days 0, 21, and 42 with OSP:TThc or OSP only, with or without dmLT, a non-toxigenic immunoadjuvant derived from heat labile toxin of Escherichia coli. PRINCIPAL FINDINGS: We detected significant serum IgG antibody responses targeting OSP following a single immunization in mice receiving OSP:TThc with or without adjuvant. Anti-LPS IgG responses were detected following a second immunization in these cohorts. No anti-OSP or anti-LPS IgG responses were detected at any time in animals receiving un-conjugated OSP with or without immunoadjuvant, and in animals receiving immunoadjuvant alone. Responses were highest following immunization with adjuvant. Serum anti-OSP IgM responses were detected in mice receiving OSP:TThc with or without immunoadjuvant, and in mice receiving unconjugated OSP. Serum anti-LPS IgM and vibriocidal responses were detected in all vaccine cohorts except in mice receiving immunoadjuvant alone. No significant IgA anti-OSP or anti-LPS responses developed in any group. Administration of OSP:TThc and adjuvant also induced memory B cell responses targeting OSP and resulted in 95% protective efficacy in a mouse lethality cholera challenge model. CONCLUSION: We describe a protectively immunogenic cholera conjugate in mice. Development of a cholera conjugate vaccine could assist in inducing long-term protective immunity, especially in young children who respond poorly to polysaccharide antigens.

  14. 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.

  15. 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.

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

    Science.gov (United States)

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

    2016-04-01

    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 choleric stool. Inactivation of IvaP influenced the activity of other secreted V. cholerae and rabbit enzymes in vivo, and genetic disruption of all four proteases increased the abundance of intelectin, an intestinal lectin, and its binding to V. cholerae in infected rabbits. Intelectin also bound to other enteric bacterial pathogens, suggesting that 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 dialog in an animal model of infection. PMID:26900865

  17. 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.

  18. CHOLERA IN BIDAR DISTRICT OF KARNATAKA STATE, INDIA

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    Pramod S

    2014-11-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate cholera from 2008 August to 2009 August, and create public health importance, in acute diarrhea diseases. Epidemic of cholera have been reported from various parts of our country. (1(2 A total fecal specimen 562 were collected, isolation and identification of pathogen was done according to standard methodology. (3 Antibiotic susceptibility pattern of the isolates were studied, and picked up randomly positive 25 isolates and were sent to national institute of cholera and enteric diseases (NICED Kolkata for confirmation and Phage typing. RESULTS: Of the 562 of patients 57 (10.142% isolates were found to be positive for vibrio. Cholera o1 and non 01/non-0139, out of 25 isolates 19 (76%. The vibrio Cholera 01 ogawa serotype, biotype Eltor and phage type T 27, T 24, T 21, T 13, along with 6 isolates (24% of Non- 0139 was also noticeable as per the report of the (NICED Kolkata. Majority of the clinical isolate were found to be resistant to more than one drug. (1(2

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

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    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.

  20. 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.

  1. Cholera in Ecuador: Current relevance of past lessons learnt

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    S S Malavade

    2011-01-01

    Full Text Available This report analyses the trends in the cholera epidemic that hit Ecuador in 1991. The study is based on personal experiences and analysis of epidemiological databases from the Ministry of Public Health of Ecuador. The number of cases and initial attack rates in an immunologically naive population are described by province. An analysis of the Andean and coastal cholera patterns of transmission are described along with its associated risk factors. The logistical, environmental, and socio-cultural risk factors prevalent during the epidemic and the control measures implemented are also reviewed. Also, the role of the epidemic in the development of the public health and healthcare resources in Ecuador is discussed here. Current data indicate favorable conditions for another outbreak of cholera in Ecuador. In view of the existing risk factors, new strategies are proposed to prevent such an epidemic in the future.

  2. 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.

  3. Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa

    Science.gov (United States)

    Pazhani, Gururaja Perumal; Abiodun, Iwalokun Bamidele; Afolabi, Oluwadun; Kolawole, Olukoya Daniel; Mukhopadhyay, Asish K.; Ramamurthy, Thanadarayan

    2016-01-01

    Background and Objectives The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality. Results All the V. cholerae O1 biotype El Tor isolates isolated during 2007–2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria. Conclusion Fecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future. PMID:27479360

  4. 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.

  5. 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.

  6. 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.

  7. Field evaluation of environmental sanitation measures against cholera.

    Science.gov (United States)

    Azurin, J C; Alvero, M

    1974-01-01

    Data obtained in a controlled field study over 5 years in 4 communities showed that the provision of sanitary facilities for human waste disposal can reduce the incidence of cholera by as much as 68%, while the provision of a safe water supply can decrease it by 73%. Where both toilets and water supplies are provided, the incidence can be reduced by as much as 76%. There was evidence that cholera infection gaining access to communities with these facilities tends to spread less and produce fewer secondary cases than in a community where such facilities are not provided. PMID:4549038

  8. Field evaluation of environmental sanitation measures against cholera*

    Science.gov (United States)

    Azurin, J. C.; Alvero, M.

    1974-01-01

    Data obtained in a controlled field study over 5 years in 4 communities showed that the provision of sanitary facilities for human waste disposal can reduce the incidence of cholera by as much as 68%, while the provision of a safe water supply can decrease it by 73%. Where both toilets and water supplies are provided, the incidence can be reduced by as much as 76%. There was evidence that cholera infection gaining access to communities with these facilities tends to spread less and produce fewer secondary cases than in a community where such facilities are not provided. PMID:4549038

  9. 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.

  10. 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.

  11. 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

  12. Cholera vaccination campaign contributes to improved knowledge regarding cholera and improved practice relevant to waterborne disease in rural Haiti.

    Directory of Open Access Journals (Sweden)

    Omowunmi Aibana

    2013-11-01

    Full Text Available BACKGROUND: Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. METHODOLOGY/PRINCIPAL FINDINGS: We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811. An OCV campaign occurred from May-June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥ 3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52-2.40, preventive methods (OR 1.83; 95% CI 1.46-2.30, and water treatment modalities (OR 2.75; 95% CI 2.16-3.50. Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28-2.05. Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03-1.64. Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14-1.89. Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35-4.51. CONCLUSION: An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

  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. Vibrio cholerae non-serogroup O1 cystitis.

    OpenAIRE

    Dumler, J.S.; Osterhout, G J; Spangler, J G; Dick, J D

    1989-01-01

    We report a case of a patient who developed cystitis caused by non-serogroup O1 Vibrio cholerae after swimming in the Chesapeake Bay. Treatment was empirical, with complete symptomatic resolution. Genitourinary tract infections by Vibrio spp. are uncommon but should be considered when cystitis occurs after saltwater exposure in appropriate geographic regions.

  15. 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.

  16. 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-

  17. 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.

  18. [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.

  19. 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.

  20. Social and cultural determinants of oral cholera vaccine uptake in Zanzibar.

    Science.gov (United States)

    Schaetti, Christian; Ali, Said M; Hutubessy, Raymond; Khatib, Ahmed M; Chaignat, Claire-Lise; Weiss, Mitchell G

    2012-09-01

    Effectiveness of mass cholera vaccination campaigns requires not only technical and financial capacity but also consideration of social and cultural factors affecting vaccine acceptance. This study examined the influence of local community views of cholera on oral cholera vaccine (OCV) uptake in a mass vaccination campaign in 2009 in peri-urban and rural areas of Zanzibar. It used data from interviews conducted before the campaign and followed previous research assessing determinants of anticipated OCV acceptance. OCV uptake was lower than the reported anticipated acceptance. Less than half of the 356 adult respondents (49.7%) drank the required two doses of OCV. Variables referring to socio-cultural features of diarrheal illness that respondents identified with a cholera case vignette explained uptake better than analysis only of socio-demographic characteristics. Somatic features of illness not specific for cholera were negative determinants. Recognition of unconsciousness as a serious sign of dehydration and concern that cholera outbreaks would overwhelm the local healthcare system in the rural area were positive determinants of acceptance. Female gender, rural residence and older age were also positive determinants of OCV uptake. For further vaccine action with OCVs, cholera as a cause of severe dehydration should be distinguished from other causes of diarrhea. Planning should acknowledge rural concern about the relationship of limited capacity of the healthcare system to cope with cholera outbreaks and the priority of a cholera vaccine. Findings recommend particular efforts to increase cholera immunization coverage among young adults, in peri-urban areas and for men. PMID:22894965

  1. 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.

  2. 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

  3. 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.

  4. Identification of a membrane-bound transcriptional regulator that links chitin and natural competence in Vibrio cholerae.

    Science.gov (United States)

    Dalia, Ankur B; Lazinski, David W; Camilli, Andrew

    2014-01-01

    Vibrio cholerae is naturally competent when grown on chitin. It is known that expression of the major regulator of competence, TfoX, is controlled by chitin; however, the molecular mechanisms underlying this requirement for chitin have remained unclear. In the present study, we identify and characterize a membrane-bound transcriptional regulator that positively regulates the small RNA (sRNA) TfoR, which posttranscriptionally enhances tfoX translation. We show that this regulation of the tfoR promoter is direct by performing electrophoretic mobility shift assays and by heterologous expression of this system in Escherichia coli. This transcriptional regulator was recently identified independently and was named "TfoS" (S. Yamamoto et al., Mol. Microbiol., in press, doi:10.1111/mmi.12462). Using a constitutively active form of TfoS, we demonstrate that the activity of this regulator is sufficient to promote competence in V. cholerae in the absence of chitin. Also, TfoS contains a large periplasmic domain, which we hypothesized interacts with chitin to regulate TfoS activity. In the heterologous host E. coli, we demonstrate that chitin oligosaccharides are sufficient to activate TfoS activity at the tfoR promoter. Collectively, these data characterize TfoS as a novel chitin-sensing transcriptional regulator that represents the direct link between chitin and natural competence in V. cholerae. IMPORTANCE Naturally competent bacteria can take up exogenous DNA from the environment and integrate it into their genome by homologous recombination. This ability to take up exogenous DNA is shared by diverse bacterial species and serves as a mechanism to acquire new genes to enhance the fitness of the organism. Several members of the family Vibrionaceae become naturally competent when grown on chitin; however, a molecular understanding of how chitin activates competence is lacking. Here, we identify a novel membrane-bound transcriptional regulator that is required for natural

  5. 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.

  6. 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.

  7. 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.

  8. 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

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

    OpenAIRE

    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. parahaemol...

  10. Coagglutination of Vibrio cholerae, Vibrio mimicus, and Vibrio vulnificus with anti-flagellar monoclonal antibody.

    OpenAIRE

    Simonson, J G; Siebeling, R J

    1988-01-01

    Monoclonal antibodies (MAbs) with serological activity for purified flagellar (H) core protein prepared from Vibrio cholerae were identified by enzyme-linked immunosorbent assay. Four of these MAbs reacted with the flagella of V. cholerae and V. mimicus exclusively, while eight MAbs reacted with at least 1 of 30 heterologous Vibrio species tested by enzyme-linked immunosorbent assay or coagglutination. It appears that V. cholerae and V. mimicus express similar, if not identical, H determinant...

  11. Immunochemical Properties of the Major Outer Membrane Protein of Vibrio cholerae

    OpenAIRE

    Kabir, Shahjahan

    1983-01-01

    Antisera to the major outer membrane protein of Vibrio cholerae (molecular weight, 48,000) raised in rabbits (i) agglutinated several strains of V. cholerae and (ii) immunoprecipitated outer membrane proteins prepared from both the biotypes and serotypes of V. cholerae. Antibodies of all isotypes to the major outer membrane protein were detected in immune human sera by enzyme-linked immunosorbent assay. These results suggest that the major outer membrane protein was the common outer membrane ...

  12. Purification and characterization of pili of a Vibrio cholerae non-O1 strain.

    OpenAIRE

    Yamashiro, T.; Nakasone, N; Iwanaga, M

    1993-01-01

    Pili of the Vibrio cholerae non-O1 strain V10 were purified and characterized. The V10 pili were physicochemically and immunologically different from those of the previously reported V. cholerae non-O1 strain S7, although the pili of the two strains had homologous N-terminal amino acid sequences. V10 plus antigen was detected only in V. cholerae non-O1 strains.

  13. The Polar Flagellar Motor of Vibrio cholerae Is Driven by an Na+ Motive Force

    OpenAIRE

    Kojima, Seiji; Yamamoto, Koichiro; Kawagishi, Ikuro; Homma, Michio

    1999-01-01

    Vibrio cholerae is a highly motile bacterium which possesses a single polar flagellum as a locomotion organelle. Motility is thought to be an important factor for the virulence of V. cholerae. The genome sequencing project of this organism is in progress, and the genes that are highly homologous to the essential genes of the Na+-driven polar flagellar motor of Vibrio alginolyticus were found in the genome database of V. cholerae. The energy source of its flagellar motor was investigated. We e...

  14. Vibrio cholerae expresses iron-regulated outer membrane proteins in vivo.

    OpenAIRE

    Sciortino, C V; Finkelstein, R A

    1983-01-01

    A comparison was made, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, of the outer membrane proteins of four strains of Vibrio cholerae grown in vivo in infant rabbits and in vitro in low-iron and iron-supplemented defined media. In vivo-grown V. cholerae expressed novel outer membrane-associated proteins which, in part, were similar to those observed on V. cholerae grown in vitro under conditions of iron deprivation.

  15. 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.

  16. 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.

  17. Worldwide occurrence of integrative conjugative element encoding multidrug resistance determinants in epidemic Vibrio cholerae O1.

    Science.gov (United States)

    Marin, Michel A; Fonseca, Erica L; Andrade, Bruno N; Cabral, Adriana C; Vicente, Ana Carolina P

    2014-01-01

    In the last decades, there has been an increase of cholera epidemics caused by multidrug resistant strains. Particularly, the integrative and conjugative element (ICE) seems to play a major role in the emergence of multidrug resistant Vibrio cholerae. This study fully characterized, by whole genome sequencing, new ICEs carried by multidrug resistant V. cholerae O1 strains from Nigeria (2010) (ICEVchNig1) and Nepal (1994) (ICEVchNep1). The gene content and gene order of these two ICEs are the same, and identical to ICEVchInd5, ICEVchBan5 and ICEVchHai1 previously identified in multidrug resistant V. cholerae O1. This ICE is characterized by dfrA1, sul2, strAB and floR antimicrobial resistance genes, and by unique gene content in HS4 and HS5 ICE regions. Screening for ICEs, in publicly available V. cholerae genomes, revealed the occurrence and widespread distribution of this ICE among V. cholerae O1. Metagenomic analysis found segments of this ICE in marine environments far from the direct influence of the cholera epidemic. Therefore, this study revealed the epidemiology of a spatio-temporal prevalent ICE in V. cholerae O1. Its occurrence and dispersion in V. cholerae O1 strains from different continents throughout more than two decades can be indicative of its role in the fitness of the current pandemic lineage.

  18. 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.

  19. Non-O1, non-O139 Vibrio cholerae bacteraemia in a cirrhotic patient

    OpenAIRE

    Petsaris, O.; Nousbaum, J B; Quilici, M L; Le Coadou, G; PAYAN, C; Abalain, M L

    2010-01-01

    Vibrio cholerae serogroups O1 or O139 are the aetiological agents of cholera. The pathogenicity of non-O1, non-O139 V. cholerae is less well known. These worldwide bacteria are responsible for gastrointestinal infections or, more rarely, bacteraemia in patients with an underlying disease, leading to life-threatening complications. We report a case of non-O1, non-O139 V. cholerae bacteraemia due to a haemolytic strain in a cirrhotic patient. Early antibiotherapy allowed a good outcome. The aim...

  20. 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.

  1. [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.

  2. "I'm not dog, no!": cries of resistance against cholera control campaigns.

    Science.gov (United States)

    Nations, M K; Monte, C M

    1996-09-01

    Popular reactions toward government efforts to control the recent cholera epidemic in Northeast Brazil are evaluated. Intensive ethnographic interviews and participant-observation in two urban slums (favelas), reveal a high level of resistance on the part of impoverished residents towards official cholera control interventions and mass media campaigns. "Non-compliance" with recommended regimens is described more as a revolt against accusatory attitudes and actions of the elite than as an outright rejection of care by the poor. "Hidden transcripts" about "The Dog's Disease," as cholera is popularly called, voices a history of social and economic inequity and domination in Northeast Brazil. Here, cholera is encumbered by the trappings of metaphor. Two lurid cultural stereotypes, pessoa imunda (filthy, dirty person) and vira lata (stray mutt dog) are used, it is believed, to equate the poor with cholera. The morally disgracing and disempowering imagery of cholera is used to blame and punish the poor and to collectively taint and separate their communities from wealthy neighborhoods. The authors argue that metaphoric trappings have tragic consequences: they deform the experience of having cholera and inhibit the sick and dying from seeking treatment early enough. Controlling cholera requires eliminating "blaming the victim" rhetoric while attacking the social roots of cholera: poverty, low earning power, female illiteracy, sexism, lack of basic sanitation and clean water supplies, medical hegemony, etc. For health interventions to be effective, it is necessary to take into account people's "hidden transcripts" when designing action programs. PMID:8888470

  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. 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.

  5. 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.

  6. 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 () disease control in Haiti.

  7. 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.

  8. 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.

  9. Cholera-Like Enterotoxins and Regulatory T cells

    OpenAIRE

    Evelyne Kohli; John Holton; John D. Clements; Cyrille Di Martino; Fatou Thiam; Christelle Basset

    2010-01-01

    Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins h...

  10. 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

  11. 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...

  12. Haiti’s progress in achieving its 10-year plan to eliminate cholera: hidden sickness cannot be cured

    OpenAIRE

    Koski-Karell, Victoria; Paul E Farmer; Isaac, Benito; Campa, Elizabeth M; Viaud, Loune; Namphy, Paul C; Ternier, Ralph; Ivers, Louise C

    2016-01-01

    Since the beginning of the cholera epidemic in Haiti 5 years ago, the prevalence of this deadly water-borne disease has fallen far below the initial rates registered during its explosive outset. However, cholera continues to cause extensive suffering and needless deaths across the country, particularly among the poor. The urgent need to eliminate transmission of cholera persists: compared to the same period in 2014, the first 4 months of 2015 saw three times the number of cholera cases. Drawi...

  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. Seasonality of cholera from 1974 to 2005: a review of global patterns

    Directory of Open Access Journals (Sweden)

    Feldacker Caryl

    2008-06-01

    Full Text Available Abstract Background The seasonality of cholera is described in various study areas throughout the world. However, no study examines how temporal cycles of the disease vary around the world or reviews its hypothesized causes. This paper reviews the literature on the seasonality of cholera and describes its temporal cycles by compiling and analyzing 32 years of global cholera data. This paper also provides a detailed literature review on regional patterns and environmental and climatic drivers of cholera patterns. Data, Methods, and Results Cholera data are compiled from 1974 to 2005 from the World Health Organization Weekly Epidemiological Reports, a database that includes all reported cholera cases in 140 countries. The data are analyzed to measure whether season, latitude, and their interaction are significantly associated with the country-level number of outbreaks in each of the 12 preceding months using separate negative binomial regression models for northern, southern, and combined hemispheres. Likelihood ratios tests are used to determine the model of best fit. The results suggest that cholera outbreaks demonstrate seasonal patterns in higher absolute latitudes, but closer to the equator, cholera outbreaks do not follow a clear seasonal pattern. Conclusion The findings suggest that environmental and climatic factors partially control the temporal variability of cholera. These results also indirectly contribute to the growing debate about the effects of climate change and global warming. As climate change threatens to increase global temperature, resulting rises in sea levels and temperatures may influence the temporal fluctuations of cholera, potentially increasing the frequency and duration of cholera outbreaks.

  15. 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

  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. Cholera in Papua New Guinea and the importance of safe water sources and sanitation

    Directory of Open Access Journals (Sweden)

    Andrew Greenhill

    2012-03-01

    Full Text Available The recent outbreak of cholera in Papua New Guinea (PNG has resulted in a large number of illnesses with a relatively high case fatality ratio (3.2%. Access to adequate sanitation and safe water is very low in PNG and has undoubtedly contributed to the spread of cholera within the country.

  18. Mapping of a gene that regulates hemolysin production in Vibrio cholerae.

    OpenAIRE

    von Mechow, S; Vaidya, A B; Bramucci, M G

    1985-01-01

    A gene that regulates the hemolysin structural gene (hly) was found to be tightly linked to the tox-1000 locus of Vibrio cholerae RJ1 and separated from hly by a large section of the V. cholerae genetic map. This hemolysin regulatory gene was designated hlyR.

  19. Vibrio cholerae tolC Is Required for Bile Resistance and Colonization

    OpenAIRE

    Bina, James E.; Mekalanos, John J.

    2001-01-01

    TolC and its homologues are outer membrane proteins that are essential for the transport of many molecules across the cell envelope. In this study we characterized the gene encoding Vibrio cholerae TolC. V. cholerae tolC mutants failed to secrete the RTX cytotoxin, were hypersensitive to antimicrobial agents, and were deficient in intestinal colonization.

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

    OpenAIRE

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

    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.

  1. Use of vaginal tampons in sewer surveys for non-O1. Vibrio cholerae.

    OpenAIRE

    Pazzaglia, G; Lesmana, M; Tjaniadi, P; Subekti, D; Kay, B.

    1993-01-01

    Vaginal tampons were shown to be a practical alternative to conventional Moore swabs for isolating Vibrio cholerae from sewage. Associated laboratory investigations demonstrated improved isolation of V. cholerae by using 12- or 18-h enrichments in alkaline peptone water, in comparison with 6-h enrichments, when cultures were incubated at ambient temperatures.

  2. 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...

  3. 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.

  4. 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, ...

  5. The two chromosomes of Vibrio cholerae are initiated at different time points in the cell cycle

    DEFF Research Database (Denmark)

    Rasmussen, Tue; Jensen, Rasmus Bugge; Skovgaard, Ole

    2007-01-01

    The bacterium Vibrio cholerae, the cause of the diarrhoeal disease cholera, has its genome divided between two chromosomes, a feature uncommon for bacteria. The two chromosomes are of different sizes and different initiator molecules control their replication independently. Using novel methods...

  6. 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...

  7. 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.

  8. Production of Antibody Raised Against Lipopolysaccharide (LPS of Vibrio Cholerae Non-O1

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    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.

  9. Comparative and genetic analyses of the putative Vibrio cholerae lipopolysaccharide core oligosaccharide biosynthesis (wav) gene cluster.

    Science.gov (United States)

    Nesper, Jutta; Kraiss, Anita; Schild, Stefan; Blass, Julia; Klose, Karl E; Bockemühl, Jochen; Reidl, Joachim

    2002-05-01

    We identified five different putative wav gene cluster types, which are responsible for the synthesis of the core oligosaccharide (OS) region of Vibrio cholerae lipopolysaccharide. Preliminary evidence that the genes encoded by this cluster are involved in core OS biosynthesis came from analysis of the recently released O1 El Tor V. cholerae genome sequence and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of O1 El Tor mutant strains defective in three genes (waaF, waaL, and wavB). Investigations of 38 different V. cholerae strains by Southern blotting, PCR, and sequencing analyses showed that the O1 El Tor wav gene cluster type is prevalent among clinical isolates of different serogroups associated with cholera and environmental O1 strains. In contrast, we found differences in the wav gene contents of 19 unrelated non-O1, non-O139 environmental and human isolates not associated with cholera. These strains contained four new wav gene cluster types that differ from each other in distinct gene loci, providing evidence for horizontal transfer of wav genes and for limited structural diversity of the core OS among V. cholerae isolates. Our results show genetic diversity in the core OS biosynthesis gene cluster and predominance of the type 1 wav gene locus in strains associated with clinical cholera, suggesting that a specific core OS structure could contribute to V. cholerae virulence.

  10. Household-level spatiotemporal patterns of incidence of cholera, Haiti, 2011.

    Science.gov (United States)

    Blackburn, Jason K; Diamond, Ulrica; Kracalik, Ian T; Widmer, Jocelyn; Brown, Will; Morrissey, B David; Alexander, Kathleen A; Curtis, Andrew J; Ali, Afsar; Morris, J Glenn

    2014-09-01

    A cholera outbreak began in Haiti during October, 2010. Spatiotemporal patterns of household-level cholera in Ouest Department showed that the initial clusters tended to follow major roadways; subsequent clusters occurred further inland. Our data highlight transmission pathway complexities and the need for case and household-level analysis to understand disease spread and optimize interventions.

  11. 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.

  12. 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.

  13. Bayesian structured additive regression modeling of epidemic data: application to cholera

    Directory of Open Access Journals (Sweden)

    Osei Frank B

    2012-08-01

    Full Text Available Abstract Background A significant interest in spatial epidemiology lies in identifying associated risk factors which enhances the risk of infection. Most studies, however, make no, or limited use of the spatial structure of the data, as well as possible nonlinear effects of the risk factors. Methods We develop a Bayesian Structured Additive Regression model for cholera epidemic data. Model estimation and inference is based on fully Bayesian approach via Markov Chain Monte Carlo (MCMC simulations. The model is applied to cholera epidemic data in the Kumasi Metropolis, Ghana. Proximity to refuse dumps, density of refuse dumps, and proximity to potential cholera reservoirs were modeled as continuous functions; presence of slum settlers and population density were modeled as fixed effects, whereas spatial references to the communities were modeled as structured and unstructured spatial effects. Results We observe that the risk of cholera is associated with slum settlements and high population density. The risk of cholera is equal and lower for communities with fewer refuse dumps, but variable and higher for communities with more refuse dumps. The risk is also lower for communities distant from refuse dumps and potential cholera reservoirs. The results also indicate distinct spatial variation in the risk of cholera infection. Conclusion The study highlights the usefulness of Bayesian semi-parametric regression model analyzing public health data. These findings could serve as novel information to help health planners and policy makers in making effective decisions to control or prevent cholera epidemics.

  14. 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. PMID:26464184

  15. 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

  16. 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.

  17. A study on the geophylogeny of clinical and environmental Vibrio cholerae in Kenya.

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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.

  20. 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. PMID:24182988

  1. 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. PMID:26828665

  2. Serine 26 in the PomB subunit of the flagellar motor is essential for hypermotility of Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    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.

  3. Genotypic and PFGE/MLVA analyses of Vibrio cholerae O1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in Thailand.

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Pandemic Spread of Cholera: Genetic Diversity and Relationships within the Seventh Pandemic Clone of Vibrio cholerae Determined by Amplified Fragment Length Polymorphism

    OpenAIRE

    Lan, Ruiting; Reeves, Peter R.

    2002-01-01

    The seventh cholera pandemic started in 1961 and continues today. A collection of 45 seventh pandemic isolates of V. cholerae sampled over a 33-year period were analyzed by amplified fragment length polymorphism (AFLP) fingerprinting. All but four pairs and one set of three isolates were distinguished. AFLP revealed far more variation than ribotyping, which was until now the most useful method of revealing variation within the pandemic clone. Unfortunately, the ribotype variation observed is ...

  10. 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.

  11. Predictive Time Series Analysis Linking Bengal Cholera with Terrestrial Water Storage Measured from Gravity Recovery and Climate Experiment Sensors.

    Science.gov (United States)

    Jutla, Antarpreet; Akanda, Ali; Unnikrishnan, Avinash; Huq, Anwar; Colwell, Rita

    2015-12-01

    Outbreaks of diarrheal diseases, including cholera, are related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. However, availability of data on water scarcity and abundance in transnational basins, are a prerequisite for developing cholera forecasting systems. With more than a decade of terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment, conditions favorable for predicting cholera occurrence may now be determined. We explored lead-lag relationships between TWS in the Ganges-Brahmaputra-Meghna basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during spring and autumn seasons, two separate logistical models between TWS and disease time series (2002-2010) were developed. TWS representing water availability showed an asymmetrical, strong association with cholera prevalence in the spring (τ = -0.53; P floods, increased odds of above average cholera in the autumn by 29% (CI = 22-33%; P < 0.05). PMID:26526921

  12. 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.

  13. 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

  14. Functional Characterization of Cholera Toxin Inhibitors Using Human Intestinal Organoids.

    Science.gov (United States)

    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

    2016-07-28

    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 IC50 values over a wide range of potencies (15 pM to 9 mM). The results indicate for the first time that an organoid-based swelling assay is a useful preclinical method to evaluate inhibitor potencies of drugs that target pathogen-derived toxins. PMID:27347611

  15. Evaluation of new primers for detecting toxigenic vibrio cholerae by multiplex PCR

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    Jalil F. Mehrabadi

    2011-08-01

    Full Text Available Vibrio cholerae is the etiological agent of cholera that has emerged as an endemic disease in different regions of the world in recent years. Traditional microbial culture and microscopy methods are considered to be the best standard for diagnosing V. cholerae infection. These methods, however, delay any available confirmatory answer by days. Molecular methods have the potential to provide sensitive, accurate, and rapid analysis of V. cholerae infection. We have developed a multiplex PCR assay to detect virulence and toxigenic-associated (VTA genes (ctxA, tcpA, and ompW. To evaluate PCR specificity, additional bacteria from the enterobacteriaceae family (Salmonella typhi, Shigella dysantry, and entrotoxigenic E. coli and Aeromonas hidrophyla were examined in this study. Specificity tests were evaluated using the genome dilution method. Importantly, the results show that our PCR specificity method represents the best tool for the rapid detection of VTA genes because of its simplicity, cost effectiveness, and accuracy. This multiplex PCR method can be used for examining the existence of VTA genes in patient samples, and therefore will distinguish V. cholerae from other vibrios and bacteria. This method is able to detect 10-100 colony forming units (CFUs of V.Cholerae and 8.5-85 picograms (pg of genomic DNA. The multiplex PCR method is also more specific and sensitive than other methods, validating it as an appropriate and sensitive tool for detecting the presence of toxigenic and pathogenic V. cholerae.

  16. 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.

  17. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

    Science.gov (United States)

    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. PMID:27425792

  18. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

    Science.gov (United States)

    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Critical analysis of compositions and protective efficacies of oral killed cholera vaccines.

    Science.gov (United States)

    Kabir, Shahjahan

    2014-09-01

    Two cholera vaccines, sold as Shanchol and Dukoral, are currently available. This review presents a critical analysis of the protective efficacies of these vaccines. Children under 5 years of age are very vulnerable to cholera and account for the highest incidence of cholera cases and more than half of the resulting deaths. Both Shanchol and Dukoral are two-spaced-dose oral vaccines comprising large numbers of killed cholera bacteria. The former contains Vibrio cholerae O1 and O139 cells, and the latter contains V. cholerae O1 cells with the recombinant B subunit of cholera toxin. In a field trial in Kolkata (India), Shanchol, the preferred vaccine, protected 45% of the test subjects in all of the age groups and only 17% of the children under 5 years of age during the first year of surveillance. In a field trial in Peru, two spaced doses of Dukoral offered negative protection in children under 5 years of age and little protection (15%) in vaccinees over 6 years of age during the first year of surveillance. Little is known about Dukoral's long-term protective efficacy. Both of these vaccines have questionable compositions, using V. cholerae O1 strains isolated in 1947 that have been inactivated by heat and formalin treatments that may denature protein. Immunological studies revealed Dukoral's reduced and short-lived efficacy, as measured by several immunological endpoints. Various factors, such as the necessity for multiple doses, poor protection of children under 5 years of age, the requirement of a cold supply chain, production costs, and complex logistics of vaccine delivery, greatly reduce the suitability of either of these vaccines for endemic or epidemic cholera control in resource-poor settings. PMID:25056361

  5. 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. PMID:25561716

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. A randomized, placebo-controlled trial of the bivalent killed, whole-cell, oral cholera vaccine in adults and children in a cholera endemic area in Kolkata, India.

    Directory of Open Access Journals (Sweden)

    Dilip Mahalanabis

    Full Text Available OBJECTIVES: An effective vaccine against cholera has been used for public health purposes in Vietnam since the 1990s. This vaccine was reformulated to meet WHO requirements. We assessed the safety and immunogenicity of the reformulated bivalent (Vibrio cholerae 01 and 0139 killed whole cell oral vaccine in a cholera endemic area in Kolkata, India. DESIGN: Double-blind, randomized, placebo controlled trial. SETTING: The trial was conducted in the clinical trial ward of the Infectious Diseases Hospital in Kolkata, India. PARTICIPANTS: The participants were 101 healthy adults (males and non-pregnant females aged 18-40 years and 100 healthy children (males and non-pregnant females aged 1-17 years. INTERVENTIONS: Participants were randomized to receive either the bivalent killed whole cell oral cholera vaccine or placebo (killed oral Escherichia coli K12. OUTCOME MEASURES: For safety: proportion of subjects with adverse events during the duration of study participation. For immunogenicity: Proportion of subjects who had a > or = 4-fold rise in serum vibriocidal antibody titers 14 days after the second dose of vaccine or placebo. RESULTS: Adverse reactions were observed with similar frequency among vaccine and placebo recipients in both age groups. Among adults 4% of vaccine and 8% of placebo recipients and among children 4% of vaccine and 2% of placebo recipients had at least one adverse event within 28 days of the first dose of the vaccine. Following immunization, 53% of adult and 80% of children vaccinees showed a > or = 4 fold rise in serum V. cholerae O1 vibriocidal antibody titers. A less pronounced response to V. cholerae O139 vibriocidal antibody titers post-immunization was noted among vaccinees. CONCLUSIONS: We found the vaccine to be safe and immunogenic in a cholera-endemic area in India. TRIAL REGISTRATION: ClinicalTrials.gov NCT00119197.

  11. [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. PMID:27049743

  12. [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.

  13. HutZ Is Required for Efficient Heme Utilization in Vibrio cholerae

    OpenAIRE

    Wyckoff, Elizabeth E.; Schmitt, Michael; Wilks, Angela; Shelley M Payne

    2004-01-01

    Vibrio cholerae, the causative agent of cholera, requires iron for growth. One mechanism by which it acquires iron is the uptake of heme, and several heme utilization genes have been identified in V. cholerae. These include three distinct outer membrane receptors, two TonB systems, and an apparent ABC transporter to transfer heme across the inner membrane. However, little is known about the fate of the heme after it enters the cell. In this report we show that a novel heme utilization protein...

  14. Parallel quorum sensing signaling pathways in Vibrio cholerae.

    Science.gov (United States)

    Jung, Sarah A; Hawver, Lisa A; Ng, Wai-Leung

    2016-05-01

    Quorum sensing (QS) is a microbial signaling process for monitoring population density and complexity. Communication among bacterial cells via QS relies on the production, secretion, and detection of small molecules called autoinducers. Many bacteria have evolved their QS systems with different network architectures to incorporate information from multiple signals. In the human pathogen Vibrio cholerae, at least four parallel signaling pathways converge to control the activity of a single regulator to modulate its QS response. By integrating multiple signal inputs, it is believed that Vibrio species can survey intra-species, intra-genus, and inter-species populations and program their gene expression accordingly. Our recent studies suggest that this "many-to-one" circuitry is also important for maintaining the integrity of the input-output relationship of the system and minimizes premature commitment to QS due to signal perturbation. Here we discuss the implications of this specific parallel network setup for V. cholerae intercellular communication and how this system arrangement affects our approach to manipulate the QS response of this clinically important pathogen. PMID:26545759

  15. 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.

  16. Cholera-like enterotoxins and Regulatory T cells.

    Science.gov (United States)

    Basset, Christelle; Thiam, Fatou; Martino, Cyrille Di; Holton, John; Clements, John D; Kohli, Evelyne

    2010-07-01

    Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB) and of LT (LTB) have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, recently, in humans, making them an attractive strategy to prevent or treat autoimmune or allergic disorders. Immunomodulation is a complex process involving many cell types notably antigen presenting cells and regulatory T cells (Tregs). In this review, we focus on Treg cells and cholera-like enterotoxins and their non toxic derivates, with regard to subtype, in vivo/in vitro effects and possible role in the modulation of immune responses to coadministered antigens. PMID:22069660

  17. Cholera-Like Enterotoxins and Regulatory T cells

    Directory of Open Access Journals (Sweden)

    Evelyne Kohli

    2010-07-01

    Full Text Available Cholera toxin (CT and the heat-labile enterotoxin of E. coli (LT, as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants. These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB and of LT (LTB have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, recently, in humans, making them an attractive strategy to prevent or treat autoimmune or allergic disorders. Immunomodulation is a complex process involving many cell types notably antigen presenting cells and regulatory T cells (Tregs. In this review, we focus on Treg cells and cholera-like enterotoxins and their non toxic derivates, with regard to subtype, in vivo/in vitro effects and possible role in the modulation of immune responses to coadministered antigens.

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. Gauze Filtration and Enrichment Procedures for Recovery of Vibrio cholerae from Contaminated Waters

    OpenAIRE

    Spira, W M; Ahmed, Q S

    1981-01-01

    Gauze filtration followed by 18-h enrichment in alkaline bile-peptone water is a simple, inexpensive, and efficient method for isolation Vibrio cholerae biotype eltor from contaminated surface waters.

  3. Genetic mapping of the regulator gene determining enterotoxin synthesis in Vibrio cholerae

    International Nuclear Information System (INIS)

    Data on the genetic mapping of mutation tox-7 (the mutation affecting the synthesis of the cholera toxin) were obtained by conjugation crosses between the atoxigenic donor strain Vibrio cholerae Eltor and the toxigenic recipient strain V. cholera classica. The molecular and genetic analysis of the Tox- recombinants indicated that, when the synthesis of the cholera toxin is disrupted in these strains, the tox-7 mutation (which impairs the regulator gene tox) is gained. Close linkage between the tox-7 and pur-63 mutations was established (during the selection procedure there was 81.1% combined transfer with respect to marker pur-63 situated in the donor strain chromosome more proximal than mutation tox-7). The markers were localized in the following order in the region under investigation: asp-cys-nal-pur-61-trp-his-pur-63-tox-7-ile

  4. 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).

  5. Regulation of competence-mediated horizontal gene transfer in the natural habitat of Vibrio cholerae.

    Science.gov (United States)

    Metzger, Lisa C; Blokesch, Melanie

    2016-04-01

    The human pathogen Vibrio cholerae is an autochthonous inhabitant of aquatic environments where it often interacts with zooplankton and their chitinous molts. Chitin induces natural competence for transformation in V. cholerae, a key mode of horizontal gene transfer (HGT). Recent comparative genomic analyses were indicative of extensive HGT in this species. However, we can still expand our understanding of the complex regulatory network that drives competence in V. cholerae. Here, we present recent advances, including the elucidation of bipartite competence regulation mediated by QstR, the inclusion of the type VI secretion system in the competence regulon of pandemic O1 El Tor strains, and the identification of TfoS as a transcriptional regulator that links chitin to competence induction in V. cholerae. PMID:26615332

  6. 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.

  7. 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)

  8. A cholera epidemic among the Nicobarese tribe of Nancowry, Andaman, and Nicobar, India.

    Science.gov (United States)

    Sugunan, Attayoor P; Ghosh, Asit R; Roy, Subarna; Gupte, Mohan D; Sehgal, Subhash C

    2004-12-01

    Cholera has not been reported from the Andaman and Nicobar Islands in India. In October 2002, an outbreak of diarrhea occurred among the Nicobarese tribe of the Nancowry group of islands. The outbreak affected 16 of the 45 inhabited villages of three islands with an attack rate of 12.8% and a case fatality ratio of 1.3%. Vibrio cholerae O1 El Tor was isolated from 18 of the 67 patients tested. A study conducted in one of the villages indicated that the outbreak was started there by a person who traveled to a nearby village where an outbreak was occurring. No specific water source could be identified as the source of infection because persons consuming water from all wells were affected. Water samples from 55 sources were tested and 38 of them were contaminated with Escherichia coli. The possible sources of V. cholerae are effluents from ships or poachers from neighboring countries where cholera is endemic. PMID:15642977

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Neuraminidase production by Vibrio cholerae O1 and other diarrheagenic bacteria.

    OpenAIRE

    Kabir, S; Ahmad, N.; Ali, S.

    1984-01-01

    Vibrio cholerae O1 strains belonging to both biotypes (classical and El Tor) and both serotypes (Ogawa and Inaba) produced neuraminidase which was released rather than cell bound. Classical strains made more neuraminidase than did El Tor strains. About one-third of V. cholerae non-O1 strains and one-fourth of Aeromonas hydrophila strains were neuraminidase positive. Strains of enterotoxigenic Escherichia coli, Vibrio parahaemolyticus, and Shigella spp. did not produce detectable neuraminidase.

  14. 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.

  15. 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.

  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. Factors affecting phaeomelanin production by a melanin-producing (mel) mutant of Vibrio cholerae.

    OpenAIRE

    Ivins, B E; Holmes, R K

    1981-01-01

    In a previous study we isolated melanin-producing (mel) mutants of Vibrio cholerae and demonstrated that production of melanin during growth on solid media was stimulated by L-tyrosine and L-cysteine. In the studies reported here we analyzed factors that affected melanin production in liquid media and determined the abilities of radioactively labeled amino acids to serve as precursors for the formation of melanin by V. cholerae. Radioactivity from L-cysteine and from L-tyrosine was preferenti...

  18. 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...

  19. Optimal allocation of the limited oral cholera vaccine supply between endemic and epidemic settings

    OpenAIRE

    Moore, Sean M.; Lessler, Justin

    2015-01-01

    The World Health Organization (WHO) recently established a global stockpile of oral cholera vaccine (OCV) to be preferentially used in epidemic response (reactive campaigns) with any vaccine remaining after 1 year allocated to endemic settings. Hence, the number of cholera cases or deaths prevented in an endemic setting represents the minimum utility of these doses, and the optimal risk-averse response to any reactive vaccination request (i.e. the minimax strategy) is one that allocates the r...

  20. A transcriptional regulator linking quorum sensing and chitin induction to render Vibrio cholerae naturally transformable

    OpenAIRE

    Lo Scrudato, Mirella; Blokesch, Melanie

    2013-01-01

    The human pathogen Vibrio cholerae is an aquatic bacterium associated with zooplankton and their chitinous exoskeletons. On chitinous surfaces, V. cholerae initiates a developmental programme, known as natural competence, to mediate transformation, which is a mode of horizontal gene transfer. Competence facilitates the uptake of free DNA and recombination into the bacterial genome. Recent studies have indicated that chitin surfaces are required, but not sufficient to induce competence. Two ad...

  1. Cholera toxin-like toxin released by Salmonella species in the presence of mitomycin C.

    OpenAIRE

    Molina, N C; Peterson, J. W.

    1980-01-01

    Several serotypes of Salmonella were shown to release increased amounts of a cholera toxin-like toxin during culture in vitro with mitomycin C (MTC). Filter-sterilized culture supernatants containing the toxin caused elongation of Chinese hamster ovary cells, which could be blocked by heating the supernatants at 100 degrees C for 15 min or by adding mixed gangliosides or monospecific cholera antitoxin. When MTC was not added to the Salmonella cultures, little or no toxin was detected in crude...

  2. Transmission of Vibrio cholerae is antagonized by lytic phage and entry into the aquatic environment.

    Directory of Open Access Journals (Sweden)

    Eric J Nelson

    2008-10-01

    Full Text Available Cholera outbreaks are proposed to propagate in explosive cycles powered by hyperinfectious Vibrio cholerae and quenched by lytic vibriophage. However, studies to elucidate how these factors affect transmission are lacking because the field experiments are almost intractable. One reason for this is that V. cholerae loses the ability to culture upon transfer to pond water. This phenotype is called the active but non-culturable state (ABNC; an alternative term is viable but non-culturable because these cells maintain the capacity for metabolic activity. ABNC bacteria may serve as the environmental reservoir for outbreaks but rigorous animal studies to test this hypothesis have not been conducted. In this project, we wanted to determine the relevance of ABNC cells to transmission as well as the impact lytic phage have on V. cholerae as the bacteria enter the ABNC state. Rice-water stool that naturally harbored lytic phage or in vitro derived V. cholerae were incubated in a pond microcosm, and the culturability, infectious dose, and transcriptome were assayed over 24 h. The data show that the major contributors to infection are culturable V. cholerae and not ABNC cells. Phage did not affect colonization immediately after shedding from the patients because the phage titer was too low. However, V. cholerae failed to colonize the small intestine after 24 h of incubation in pond water-the point when the phage and ABNC cell titers were highest. The transcriptional analysis traced the transformation into the non-infectious ABNC state and supports models for the adaptation to nutrient poor aquatic environments. Phage had an undetectable impact on this adaptation. Taken together, the rise of ABNC cells and lytic phage blocked transmission. Thus, there is a fitness advantage if V. cholerae can make a rapid transfer to the next host before these negative selective pressures compound in the aquatic environment.

  3. 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

  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. 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.

  6. 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. PMID:26904017

  7. 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. PMID:27407302

  8. In vitro antibacterial activity of onion (allium cepa) against clinical isolates of vibrio cholera

    International Nuclear Information System (INIS)

    Background: Cholera is a major public health problem in developing countries of the world. Bacterial resistance, lack of surveillance data and proper microbiological facilities are major problems regarding diagnosis of cholera. The spread of microbial drug resistance is a global public health challenge that results in increased illness and death rate. Newer antimicrobials or agents are urgently required to overcome this problem. This work was therefore done to investigate the antimicrobial potential of onion against thirty-three clinical isolates of Vibrio cholera. Methods: The extract was prepared by reflux extraction method. Antibacterial screening of clinical isolates of V. cholerae was done by agar well diffusion method. Agar dilution method was used to assess the Minimum Inhibitory Concentration (MIC). Results: All tested strains of V. cholerae were sensitive to onion (Allium cepa) extracts of two types (purple and yellow). Purple type of extract had MIC range of 19.2-21.6 mg/ml. The extract of yellow type onion had an MIC range of 66-68.4 mg/ml. Conclusion: The results indicated that onion (Allium cepa) has an inhibitory effect on V. cholerae. Keeping in view the anti-bacterial activity of this compound can be exploited as a therapeutic agent in an animal model. This finding is a positive point for further investigation of this herb of traditional medicine. (author)

  9. Multi-locus variable number tandem repeat analysis of 7th pandemic Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    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. Increased isolation frequency of toxigenic Vibrio cholerae O1 from environmental monitoring sites in Haiti.

    Directory of Open Access Journals (Sweden)

    Meer T Alam

    Full Text Available 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.

  11. [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.

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

    Directory of Open Access Journals (Sweden)

    Racheal W. Kimani

    2014-04-01

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

  13. Molecular epidemiology of non-O1 Vibrio cholerae and Vibrio mimicus in the U.S. Gulf Coast region.

    OpenAIRE

    Kaper, J B; Nataro, J P; Roberts, N C; Siebeling, R J; Bradford, H B

    1986-01-01

    Ten toxigenic Vibrio cholerae non-O1 and V. mimicus strains isolated from clinical and environmental sources in the U.S. Gulf Coast region were examined for genetic relatedness. Restriction digest patterns of chromosomal DNA and Southern blot analysis with a cholera toxin gene probe revealed that the strains exhibited greater genetic divergence than the highly conserved V. cholerae O1 strains isolated from clinical and sewage samples in this region.

  14. Cloning of a Vibrio cholerae vibriobactin gene cluster: identification of genes required for early steps in siderophore biosynthesis.

    OpenAIRE

    Wyckoff, E E; Stoebner, J A; Reed, K E; Payne, S M

    1997-01-01

    Vibrio cholerae secretes the catechol siderophore vibriobactin in response to iron limitation. Vibriobactin is structurally similar to enterobactin, the siderophore produced by Escherichia coli, and both organisms produce 2,3-dihydroxybenzoic acid (DHBA) as an intermediate in siderophore biosynthesis. To isolate and characterize V. cholerae genes involved in vibriobactin biosynthesis, we constructed a genomic cosmid bank of V. cholerae DNA and isolated clones that complemented mutations in E....

  15. Safety of the recombinant cholera toxin B subunit, killed whole-cell (rBS-WC oral cholera vaccine in pregnancy.

    Directory of Open Access Journals (Sweden)

    Ramadhan Hashim

    Full Text Available INTRODUCTION: Mass vaccinations are a main strategy in the deployment of oral cholera vaccines. Campaigns avoid giving vaccine to pregnant women because of the absence of safety data of the killed whole-cell oral cholera (rBS-WC vaccine. Balancing this concern is the known higher risk of cholera and of complications of pregnancy should cholera occur in these women, as well as the lack of expected adverse events from a killed oral bacterial vaccine. METHODOLOGY/PRINCIPAL FINDINGS: From January to February 2009, a mass rBS-WC vaccination campaign of persons over two years of age was conducted in an urban and a rural area (population 51,151 in Zanzibar. Pregnant women were advised not to participate in the campaign. More than nine months after the last dose of the vaccine was administered, we visited all women between 15 and 50 years of age living in the study area. The outcome of pregnancies that were inadvertently exposed to at least one oral cholera vaccine dose and those that were not exposed was evaluated. 13,736 (94% of the target women in the study site were interviewed. 1,151 (79% of the 1,453 deliveries in 2009 occurred during the period when foetal exposure to the vaccine could have occurred. 955 (83% out of these 1,151 mothers had not been vaccinated; the remaining 196 (17% mothers had received at least one dose of the oral cholera vaccine. There were no statistically significant differences in the odds ratios for birth outcomes among the exposed and unexposed pregnancies. CONCLUSIONS/SIGNIFICANCE: We found no statistically significant evidence of a harmful effect of gestational exposure to the rBS-WC vaccine. These findings, along with the absence of a rational basis for expecting a risk from this killed oral bacterial vaccine, are reassuring but the study had insufficient power to detect infrequent events. TRIAL REGISTRATION: ClinicalTrials.gov NCT00709410.

  16. Identification and characterization of Vibrio cholerae surface proteins by radioiodination

    International Nuclear Information System (INIS)

    Whole cells and isolated outer membrane from Vibrio cholerae (Classical, Inaba) were radiolabeled with Iodogen or Iodo-beads as catalyst. Radiolabeling of whole cells was shown to be surface specific by sodium dodecyl sulfate-urea polyacrylamide gel electrophoresis of whole cells and cell fractions. Surface-labeled whole cells regularly showed 16 distinguishable protein species, of which nine were found in radiolabeled outer membrane preparations obtained by a lithium chloride- lithium acetate procedure. Eight of these proteins were found in outer membranes prepared by sucrose density gradient centrifugation and Triton X-100 extraction of radiolabeled whole cells. The mobility of several proteins was shown to be affected by temperature, and the major protein species exposed on the cell surface was shown to consist of at least two different peptides

  17. Nanostructured magnesium oxide biosensing platform for cholera detection

    Science.gov (United States)

    Patel, Manoj K.; Azahar Ali, Md.; Agrawal, Ved V.; Ansari, Z. A.; Ansari, S. G.; Malhotra, B. D.

    2013-04-01

    We report fabrication of highly crystalline nanostructured magnesium oxide (NanoMgO, size >30 nm) film electrophoretically deposited onto indium-tin-oxide (ITO) glass substrate for Vibrio cholerae detection. The single stranded deoxyribonucleic acid (ssDNA) probe, consisting of 23 bases (O1 gene sequence) immobilized onto NanoMgO/ITO electrode surface, has been characterized using electrochemical, Fourier Transform-Infra Red, and UltraViolet-visible spectroscopic techniques. The hybridization studies of ssDNA/NanoMgO/ITO bioelectrode with fragmented target DNA conducted using differential pulse voltammetry reveal sensitivity as 16.80 nA/ng/cm2, response time of 3 s, linearity as 100-500 ng/μL, and stability of about 120 days.

  18. A Spatially Explicit and Seasonally Varying Cholera Prevalence Model With Distributed Macro-Scale Environmental and Hydroclimatic Forcings

    Science.gov (United States)

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

    2011-12-01

    Despite major advances in the ecological and microbiological understanding of the bacterium Vibrio cholerae, the role of underlying large-scale processes in the progression of the cholera disease in space and time is not well understood. Here, we present a spatially explicit and seasonally varying coupled hydroclimatology-epidemiology model for understanding regional scale cholera prevalence in response to large scale hydroclimatic and environmental forcings. Our results show that environmental cholera transmission can be modulated by two spatially and seasonally distinct mechanisms - influenced by dry and wet season hydrologic determinants. The model is applied to the Ganges-Brahmaputra-Meghna Basin areas in Bangladesh to simulate spatially explicit cholera prevalence rates, and validated with long-term cholera data from Dhaka and shorter-term records from regional surveillance locations. The model reproduces the variability of cholera prevalence at monthly, seasonal, and interannual timescales and highlights the role of asymmetric large scale hydroclimatic processes as the dominant controls. Our findings have important implications for formulating effective cholera intervention strategies, and for understanding the impacts of changing climate patterns on seasonal cholera transmission.

  19. Role of receptor-mediated endocytosis, endosomal acidification and cathepsin D in cholera toxin cytotoxicity.

    Science.gov (United States)

    El Hage, Tatiana; Merlen, Clémence; Fabrega, Sylvie; Authier, François

    2007-05-01

    Using the in situ liver model system, we have recently shown that, after cholera toxin binding to hepatic cells, cholera toxin accumulates in a low-density endosomal compartment, and then undergoes endosomal proteolysis by the aspartic acid protease cathepsin-D [Merlen C, Fayol-Messaoudi D, Fabrega S, El Hage T, Servin A, Authier F (2005) FEBS J272, 4385-4397]. Here, we have used a subcellular fractionation approach to address the in vivo compartmentalization and cytotoxic action of cholera toxin in rat liver parenchyma. Following administration of a saturating dose of cholera toxin to rats, rapid endocytosis of both cholera toxin subunits was observed, coincident with massive internalization of both the 45 kDa and 47 kDa Gsalpha proteins. These events coincided with the endosomal recruitment of ADP-ribosylation factor proteins, especially ADP-ribosylation factor-6, with a time course identical to that of toxin and the A subunit of the stimulatory G protein (Gsalpha) translocation. After an initial lag phase of 30 min, these constituents were linked to NAD-dependent ADP-ribosylation of endogenous Gsalpha, with maximum accumulation observed at 30-60 min postinjection. Assessment of the subsequent postendosomal fate of internalized Gsalpha revealed sustained endolysosomal transfer of the two Gsalpha isoforms. Concomitantly, cholera toxin increased in vivo endosome acidification rates driven by the ATP-dependent H(+)-ATPase pump and in vitro vacuolar acidification in hepatoma HepG2 cells. The vacuolar H(+)-ATPase inhibitor bafilomycin and the cathepsin D inhibitor pepstatin A partially inhibited, both in vivo and in vitro, the cAMP response to cholera toxin. This cathepsin D-dependent action of cholera toxin under the control of endosomal acidity was confirmed using cellular systems in which modification of the expression levels of cathepsin D, either by transfection of the cathepsin D gene or small interfering RNA, was followed by parallel changes in the cytotoxic

  20. Role of receptor-mediated endocytosis, endosomal acidification and cathepsin D in cholera toxin cytotoxicity.

    Science.gov (United States)

    El Hage, Tatiana; Merlen, Clémence; Fabrega, Sylvie; Authier, François

    2007-05-01

    Using the in situ liver model system, we have recently shown that, after cholera toxin binding to hepatic cells, cholera toxin accumulates in a low-density endosomal compartment, and then undergoes endosomal proteolysis by the aspartic acid protease cathepsin-D [Merlen C, Fayol-Messaoudi D, Fabrega S, El Hage T, Servin A, Authier F (2005) FEBS J272, 4385-4397]. Here, we have used a subcellular fractionation approach to address the in vivo compartmentalization and cytotoxic action of cholera toxin in rat liver parenchyma. Following administration of a saturating dose of cholera toxin to rats, rapid endocytosis of both cholera toxin subunits was observed, coincident with massive internalization of both the 45 kDa and 47 kDa Gsalpha proteins. These events coincided with the endosomal recruitment of ADP-ribosylation factor proteins, especially ADP-ribosylation factor-6, with a time course identical to that of toxin and the A subunit of the stimulatory G protein (Gsalpha) translocation. After an initial lag phase of 30 min, these constituents were linked to NAD-dependent ADP-ribosylation of endogenous Gsalpha, with maximum accumulation observed at 30-60 min postinjection. Assessment of the subsequent postendosomal fate of internalized Gsalpha revealed sustained endolysosomal transfer of the two Gsalpha isoforms. Concomitantly, cholera toxin increased in vivo endosome acidification rates driven by the ATP-dependent H(+)-ATPase pump and in vitro vacuolar acidification in hepatoma HepG2 cells. The vacuolar H(+)-ATPase inhibitor bafilomycin and the cathepsin D inhibitor pepstatin A partially inhibited, both in vivo and in vitro, the cAMP response to cholera toxin. This cathepsin D-dependent action of cholera toxin under the control of endosomal acidity was confirmed using cellular systems in which modification of the expression levels of cathepsin D, either by transfection of the cathepsin D gene or small interfering RNA, was followed by parallel changes in the cytotoxic

  1. [Epidemic Cholera and American Reform Movements in the 19th Century].

    Science.gov (United States)

    Kim, Seohyung

    2015-12-01

    The 19th century was the age of great reform in American history. After constructing of the canal and railroads, the industrialization began and American society changed so rapidly. In this period, there were so many social crisis and American people tried to solve these problems within the several reform movements. These reform movements were the driving forces to control cholera during the 19th century. Cholera was the endemic disease in Bengal, India, but after the 19th century it had spread globally by the development of trade networks. The 1832 cholera in the United States was the first epidemic cholera in American history. The mortality of cholera was so high, but it was very hard to find out the cause of this fatal infectious disease. So, different social discourses happened to control epidemic cholera in the 19th century, these can be understood within the similar context of American reform movements during this period. Board of Health in New York States made a new public health act to control cholera in 1832, it was ineffective. Some people insisted that the cause of this infectious disease was the corruption of the United States. They emphasized unjust and immoral system in American society. Moral reform expanded to Nativism, because lots of Irish immigrants were the victims of cholera. So, epidemic cholera was the opportunity to spread the desire for moral reform. To control cholera in 1849, the sanitary reform in Britain had affected. The fact that it was so important to improve and maintain the water quality for the control and prevention of disease spread, the sanitary reform happened. There were two different sphere of the sanitary reform. The former was the private reform to improve sewer or privy, the latter was the public reform to build sewage facilities. The 1849 cholera had an important meaning, because the social discourse, which had emphasized the sanitation of people or home expanded to the public sphere. When cholera broke out in 1866 again

  2. The Type II secretion system delivers matrix proteins for biofilm formation by Vibrio cholerae.

    Science.gov (United States)

    Johnson, Tanya L; Fong, Jiunn C; Rule, Chelsea; Rogers, Andrew; Yildiz, Fitnat H; Sandkvist, Maria

    2014-12-01

    Gram-negative bacteria have evolved several highly dedicated pathways for extracellular protein secretion, including the type II secretion (T2S) system. Since substrates secreted via the T2S system include both virulence factors and degradative enzymes, this secretion system is considered a major survival mechanism for pathogenic and environmental species. Previous analyses revealed that the T2S system mediates the export of ≥ 20 proteins in Vibrio cholerae, a human pathogen that is indigenous to the marine environment. Here we demonstrate a new role in biofilm formation for the V. cholerae T2S system, since wild-type V. cholerae was found to secrete the biofilm matrix proteins RbmC, RbmA, and Bap1 into the culture supernatant, while an isogenic T2S mutant could not. In agreement with this finding, the level of biofilm formation in a static microtiter assay was diminished in T2S mutants. Moreover, inactivation of the T2S system in a rugose V. cholerae strain prevented the development of colony corrugation and pellicle formation at the air-liquid interface. In contrast, extracellular secretion of the exopolysaccharide VPS, an essential component of the biofilm matrix, remained unaffected in the T2S mutants. Our results indicate that the T2S system provides a mechanism for the delivery of extracellular matrix proteins known to be important for biofilm formation by V. cholerae. Because the T2S system contributes to the pathogenicity of V. cholerae by secreting proteins such as cholera toxin and biofilm matrix proteins, elucidation of the molecular mechanism of T2S has the potential to lead to the development of novel preventions and therapies. PMID:25266381

  3. Strategies to Prevent Cholera Introduction during International Personnel Deployments: A Computational Modeling Analysis Based on the 2010 Haiti Outbreak.

    Directory of Open Access Journals (Sweden)

    Joseph A Lewnard

    2016-01-01

    Full Text Available Introduction of Vibrio cholerae to Haiti during the deployment of United Nations (UN peacekeepers in 2010 resulted in one of the largest cholera epidemics of the modern era. Following the outbreak, a UN-commissioned independent panel recommended three pre-deployment intervention strategies to minimize the risk of cholera introduction in future peacekeeping operations: screening for V. cholerae carriage, administering prophylactic antimicrobial chemotherapies, or immunizing with oral cholera vaccines. However, uncertainty regarding the effectiveness of these approaches has forestalled their implementation by the UN. We assessed how the interventions would have impacted the likelihood of the Haiti cholera epidemic.We developed a stochastic model for cholera importation and transmission, fitted to reported cases during the first weeks of the 2010 outbreak in Haiti. Using this model, we estimated that diagnostic screening reduces the probability of cases occurring by 82% (95% credible interval: 75%, 85%; however, false-positive test outcomes may hamper this approach. Antimicrobial chemoprophylaxis at time of departure and oral cholera vaccination reduce the probability of cases by 50% (41%, 57% and by up to 61% (58%, 63%, respectively. Chemoprophylaxis beginning 1 wk before departure confers a 91% (78%, 96% reduction independently, and up to a 98% reduction (94%, 99% if coupled with vaccination. These results are not sensitive to assumptions about the background cholera incidence rate in the endemic troop-sending country. Further research is needed to (1 validate the sensitivity and specificity of rapid test approaches for detecting asymptomatic carriage, (2 compare prophylactic efficacy across antimicrobial regimens, and (3 quantify the impact of oral cholera vaccine on transmission from asymptomatic carriers.Screening, chemoprophylaxis, and vaccination are all effective strategies to prevent cholera introduction during large-scale personnel

  4. Genome Sequence of the K139-Like Phage VcP032 Originating from the Vibrio cholerae O1 El Tor Ogawa Serotype.

    Science.gov (United States)

    Jäckel, Claudia; Strauch, Eckhard; Hammerl, Jens Andre

    2016-01-01

    Vibrio cholerae is the cause of large cholera outbreaks, especially in endemic regions with high poverty and inadequate sanitation. Here, we announce the complete genome sequence of the virulence-associated broad host range V. cholerae phage VcP032, including a brief summary of its genotypic and phenotypic features. PMID:27445393

  5. Genome Sequence of the K139-Like Phage VcP032 Originating from Vibrio cholerae O1 El Tor Ogawa Serotype

    Science.gov (United States)

    Jäckel, Claudia; Hammerl, Jens Andre

    2016-01-01

    Vibrio cholerae is the cause of large cholera outbreaks, especially in endemic regions with high poverty and inadequate sanitation. Here, we announce the complete genome sequence of the virulence-associated broad host range V. cholerae phage VcP032, including a brief summary of its genotypic and phenotypic features. PMID:27445393

  6. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer; Ngandjio, Antoinette; Nzouankeu, Ariane;

    2016-01-01

    The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic...

  7. Construction and preclinical evaluation of mmCT, a novel mutant cholera toxin adjuvant that can be efficiently produced in genetically manipulated Vibrio cholerae.

    Science.gov (United States)

    Lebens, Michael; Terrinoni, Manuela; Karlsson, Stefan L; Larena, Maximilian; Gustafsson-Hedberg, Tobias; Källgård, Susanne; Nygren, Erik; Holmgren, Jan

    2016-04-19

    There is an urgent need for new adjuvants that are effective with mucosally administered vaccines. Cholera toxin (CT) is the most powerful known mucosal adjuvant but is much too toxic for human use. In an effort to develop a useful mucosal adjuvant we have generated a novel non-toxic mutant CT molecule that retains much of the adjuvant activity of native CT. This was achieved by making the enzymatically active A subunit (CTA) recalcitrant to the site-specific proteolytic cleavage ("nicking") required for toxicity, which was found to require mutations not only in the two residues rendering the molecule resistant to trypsin but also in neighboring sites protecting against cleavage by Vibrio cholerae proteases. This multiple-mutated CT (mmCT) adjuvant protein could be efficiently produced in and purified from the extracellular medium of CT-deleted V. cholerae. The mmCT completely lacked detectable enterotoxicity in an infant mouse model and had >1000-fold reduced cAMP inducing activity compared to native CT in a sensitive mammalian target cell system. It nonetheless proved to have potent adjuvant activity on mucosal and systemic antibody as well as cellular immune responses to mucosally co-administered antigens including oral cholera and intranasal influenza vaccines. We conclude that mmCT is an attractive novel non-toxic mucosal adjuvant for enhancing immune responses to co-administered mucosal vaccines. PMID:26973069

  8. Informal urban settlements and cholera risk in Dar es Salaam, Tanzania.

    Directory of Open Access Journals (Sweden)

    Katherine Penrose

    Full Text Available BACKGROUND: As a result of poor economic opportunities and an increasing shortage of affordable housing, much of the spatial growth in many of the world's fastest-growing cities is a result of the expansion of informal settlements where residents live without security of tenure and with limited access to basic infrastructure. Although inadequate water and sanitation facilities, crowding and other poor living conditions can have a significant impact on the spread of infectious diseases, analyses relating these diseases to ongoing global urbanization, especially at the neighborhood and household level in informal settlements, have been infrequent. To begin to address this deficiency, we analyzed urban environmental data and the burden of cholera in Dar es Salaam, Tanzania. METHODOLOGY/PRINCIPAL FINDINGS: Cholera incidence was examined in relation to the percentage of a ward's residents who were informal, the percentage of a ward's informal residents without an improved water source, the percentage of a ward's informal residents without improved sanitation, distance to the nearest cholera treatment facility, population density, median asset index score in informal areas, and presence or absence of major roads. We found that cholera incidence was most closely associated with informal housing, population density, and the income level of informal residents. Using data available in this study, our model would suggest nearly a one percent increase in cholera incidence for every percentage point increase in informal residents, approximately a two percent increase in cholera incidence for every increase in population density of 1000 people per km(2 in Dar es Salaam in 2006, and close to a fifty percent decrease in cholera incidence in wards where informal residents had minimally improved income levels, as measured by ownership of a radio or CD player on average, in comparison to wards where informal residents did not own any items about which they were

  9. Comparative genomic analysis reveals evidence of two novel Vibrio species closely related to V. cholerae

    Directory of Open Access Journals (Sweden)

    Brettin Thomas S

    2010-05-01

    Full Text Available Abstract Background In recent years genome sequencing has been used to characterize new bacterial species, a method of analysis available as a result of improved methodology and reduced cost. Included in a constantly expanding list of Vibrio species are several that have been reclassified as novel members of the Vibrionaceae. The description of two putative new Vibrio species, Vibrio sp. RC341 and Vibrio sp. RC586 for which we propose the names V. metecus and V. parilis, respectively, previously characterized as non-toxigenic environmental variants of V. cholerae is presented in this study. Results Based on results of whole-genome average nucleotide identity (ANI, average amino acid identity (AAI, rpoB similarity, MLSA, and phylogenetic analysis, the new species are concluded to be phylogenetically closely related to V. cholerae and V. mimicus. Vibrio sp. RC341 and Vibrio sp. RC586 demonstrate features characteristic of V. cholerae and V. mimicus, respectively, on differential and selective media, but their genomes show a 12 to 15% divergence (88 to 85% ANI and 92 to 91% AAI compared to the sequences of V. cholerae and V. mimicus genomes (ANI Vibrio sp. RC341 and Vibrio sp. RC586 share 2104 ORFs (59% and 2058 ORFs (56% with the published core genome of V. cholerae and 2956 (82% and 3048 ORFs (84% with V. mimicus MB-451, respectively. The novel species share 2926 ORFs with each other (81% Vibrio sp. RC341 and 81% Vibrio sp. RC586. Virulence-associated factors and genomic islands of V. cholerae and V. mimicus, including VSP-I and II, were found in these environmental Vibrio spp. Conclusions Results of this analysis demonstrate these two environmental vibrios, previously characterized as variant V. cholerae strains, are new species which have evolved from ancestral lineages of the V. cholerae and V. mimicus clade. The presence of conserved integration loci for genomic islands as well as evidence of horizontal gene transfer between these two new

  10. Review of two decades of cholera diagnostics--how far have we really come?

    Directory of Open Access Journals (Sweden)

    Michal H Dick

    Full Text Available BACKGROUND: Cholera, an ancient scourge, continues to inflict high rates of mortality today. The rising incidence of epidemics in areas of poor sanitation and crowding highlight the need for better epidemic prevention and early response. Such interventions require the availability of rapid and accurate diagnostic techniques to trigger timely response and mitigate the scale of the outbreak. The current gold standard of bacterial culture is inadequate for rapid diagnosis, highlighting the overarching neglect of field diagnostic needs. This paper was written to support the World Health Organisation's Global Task Force on Cholera Control mandated Cholera and diarrhoeal disease laboratory Network (CholdiNet in devising a protocol for the validation of Rapid Diagnostic Tests (RDTs for Vibrio cholerae. The status of diagnostic tools for Vibrio cholerae is assessed, describing products that have been commercialised over the last two decades and discussing their peer-reviewed evaluation. METHOD: Review of post-1990 peer-reviewed and grey literature on rapid diagnostic tests for Vibrio cholerae. RESULTS: Since 1990, twenty four diagnostic tests have been developed for the detection of Vibrio cholerae in human faecal samples. Fourteen of these have also been described in the literature, with rapid chromatographic-immuno assays (CIA featuring strongly. Polymerase chain reaction (PCR assays maintain the ability to detect the lowest amount of bacteria; however CIAs achieve both low detection thresholds and high sensitivity and specificity, making them possible candidates for use in field conditions. Field and laboratory studies were performed in a wide range of settings demonstrating variability in performance, however only a few of these studies were sufficiently stringent, highlighting five RDTs that showed promise in field conditions; COAT, IP cholera dipstick, SMART, IP dipstick and Medicos. In light of non-independent reporting, the authors would like to

  11. Obtaining of a rapid diagnostic test for Cholera, based on latex particles coupled with a monoclonal antibody against Vibrio cholera O1 lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Fátima Reyes-López

    2015-08-01

    Full Text Available Cholera is an acute contagious intestinal disease caused by ingestion of food or water contaminated with O1 and O139 serotypes of the bacterium Vibrio cholerae. Cholera is characterized by abundant secretory diarrhea leading to dehydration. Death occurs within hours without treatment, so early diagnosis is very important, especially at the beginning of the disease, because it is difficult to differentiate from other acute diarrheal diseases. The diagnostic golden test is the stool culture; however, it does not guarantee a rapid detection of the disease. Rapid tests have been recently developed; they are based on test strips and agglutination with latex particles, which are very effective, but difficult to acquire for their high prices. The objective of this research was to obtain a quick assay based on latex particles coupled with a monoclonal antibody (mAb against V. cholerae O1 lipopolysaccharide obtained in Finlay Institute. Latex particles of 0.8 µm were used in a 10% suspension, and they were coupled to the mAb (0.25 mg/ml for 2 hours at 37°C. The sensitivity, specificity and performance were evaluated in 84 stool samples from patients with presumptive diagnosis of cholera. The diagnostic test obtained showed no cross-reactivity against no-O1 strains and other enteropathogens. Latex diagnostic test showed values of sensitivity, specificity and efficacy of 97.87; 97.29 and 97.6% respectively, very similar to the commercial diagnostic test CTK- Biotech. The latex reagent obtained can be used in the rapid diagnosis of the disease.

  12. Imported cholera with acute renal failure after a short business-trip to the Philippines, Germany, October 2015.

    Science.gov (United States)

    Slesak, Günther; Fleck, Ralf; Jacob, Daniela; Grunow, Roland; Schäfer, Johannes

    2016-01-01

    A German businessman developed acute watery diarrhoea after a three-day trip to the Philippines. He was admitted with severe hypotension and acute renal failure, but recovered with rapid rehydration. Vibrio cholerae O1 serotype Ogawa was isolated. Physicians need to be aware of endemic cholera in Asia including the Philippines and consider this in their pre-travel advice.

  13. A pelagic outbreak of avian cholera in North American gulls: Scavenging as a primary mechanism for transmission?

    Science.gov (United States)

    Wille, Michelle; McBurney, Scott; Robertson, Gregory J.; Wilhelm, Sabine; Blehert, David; Soos, Catherine; Dunphy, Ron; Whitney, Hugh

    2016-01-01

    Avian cholera, caused by the bacterium Pasteurella multocida, is an endemic disease globally, often causing annual epizootics in North American wild bird populations with thousands of mortalities. From December 2006 to March 2007, an avian cholera outbreak caused mortality in marine birds off the coast of Atlantic Canada, largely centered 300–400 km off the coast of the island of Newfoundland. Scavenging gulls (Larus spp.) were the primary species detected; however, mortality was also identified in Black-legged Kittiwakes (Rissa tridactyla) and one Common Raven (Corvus corax), a nonmarine species. The most common gross necropsy findings in the birds with confirmed avian cholera were acute fibrinous and necrotizing lesions affecting the spleen, air sacs, and pericardium, and nonspecific hepatomegaly and splenomegaly. The etiologic agent, P. multocida serotype 1, was recovered from 77 of 136 carcasses examined, and confirmed or probable avian cholera was diagnosed in 85 cases. Mortality observed in scavenging gull species was disproportionately high relative to their abundance, particularly when compared to nonscavenging species. The presence of feather shafts in the ventricular lumen of the majority of larid carcasses diagnosed with avian cholera suggests scavenging of birds that died from avian cholera as a major mode of transmission. This documentation of an outbreak of avian cholera in a North American pelagic environment affecting primarily scavenging gulls indicates that offshore marine environments may be a component of avian cholera dynamics.

  14. Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

    International Nuclear Information System (INIS)

    Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

  15. VIBRIO CHOLERAE 01 CAN ASSUME A "RUGOSE" SURVIVAL FORM THAT RESISTS KILLING BY CHLORINE, YET RETAINS VIRULENCE

    Science.gov (United States)

    V. cholerae 01 are able to shift between smooth and "wrinkled" or "rugose" colonial morphologies. ultures of smooth V. cholerae strains were inactivated in less than 40 and 20 seconds by concentrations of 0.5 mg/L and 1.0 mg/L free chlorine, respectively. n contrast, cultures of ...

  16. Active surveillance of the aquatic environment for potential prediction, prevention and spread of water borne disease: the cholera paradigm

    Science.gov (United States)

    Huq, A.; Colwell, R.

    2011-12-01

    Based on results of ecological and epidemiological studies, occurrence and spread of certain diseases are more fully understood. Cholera is a major waterborne disease, that is relatively easily treatable and clearly preventable, yet tens of thousands die each year worldwide. A dose dependent disease, the infectious dose can vary from 103-106, depending on health status of the victim. Historically, cholera has been shown to spread from person to person. Furthermore, the disease is caused predominantly via ingestion of contaminated water and most of the outbreaks that have been recorded worldwide originated in a coastal region. Using appropriate detection methods, Vibrio cholerae can be isolated from samples collected from ponds, rivers, estuaries, and coastal waters globally. The populations of V. cholerae may vary in numbers during different seasons of the year. It is important to have a clear understanding of the distribution of the causative agent in the environment as such information can assist public health officials in taking action to prevent outbreaks of cholera. Thus an effective monitoring program is critical, particularly in light of climate change with temperature extremes more likely to be occurring. Based on a predictive model and results of ground truth data, temperature has been found to be a factor in the increase of V. cholerae in the environment. Correlation was observed with occurrence of cholera and both temperature and salinity. More recent research indicates additional factors need to be considered in predicting cholera epidemics, including the hydrology and disease dynamics.

  17. Vibrio cholerae non-O1 non-O139 infection in an immunocompromised patient returning from Spain, July 2009.

    Science.gov (United States)

    Rozemeijer, W; Korswagen, L A; Voskuyl, A E; Budding, A E

    2009-01-01

    We describe a severe gastroenteritis with non-O1, non-O139 Vibrio cholerae in an immunocompromised patient returning from a holiday in Spain in July 2009. Predisposing factors and possible cholera enterotoxin production could explain the unusually grave symptomatology. Patient recovered after doxycyclin treatment. PMID:19679033

  18. Determination of tolerable fatty acids and cholera toxin concentrations using human intestinal epithelial cells and BALB/c mouse macrophages.

    Science.gov (United States)

    Tamari, Farshad; Tychowski, Joanna; Lorentzen, Laura

    2013-01-01

    The positive role of fatty acids in the prevention and alleviation of non-human and human diseases have been and continue to be extensively documented. These roles include influences on infectious and non-infectious diseases including prevention of inflammation as well as mucosal immunity to infectious diseases. Cholera is an acute intestinal illness caused by the bacterium Vibrio cholerae. It occurs in developing nations and if left untreated, can result in death. While vaccines for cholera exist, they are not always effective and other preventative methods are needed. We set out to determine tolerable concentrations of three fatty acids (oleic, linoleic and linolenic acids) and cholera toxin using mouse BALB/C macrophages and human intestinal epithelial cells, respectively. We solubilized the above fatty acids and used cell proliferation assays to determine the concentration ranges and specific concentrations of the fatty acids that are not detrimental to human intestinal epithelial cell viability. We solubilized cholera toxin and used it in an assay to determine the concentration ranges and specific concentrations of cholera toxin that do not statistically decrease cell viability in BALB/C macrophages. We found the optimum fatty acid concentrations to be between 1-5 ng/μl, and that for cholera toxin to be < 30 ng per treatment. This data may aid future studies that aim to find a protective mucosal role for fatty acids in prevention or alleviation of cholera infections. PMID:23748896

  19. Avian cholera, a threat to the viability of an Arctic seabird colony?

    Directory of Open Access Journals (Sweden)

    Sébastien Descamps

    Full Text Available Evidence that infectious diseases cause wildlife population extirpation or extinction remains anecdotal and it is unclear whether the impacts of a pathogen at the individual level can scale up to population level so drastically. Here, we quantify the response of a Common eider colony to emerging epidemics of avian cholera, one of the most important infectious diseases affecting wild waterfowl. We show that avian cholera has the potential to drive colony extinction, even over a very short period. Extinction depends on disease severity (the impact of the disease on adult female survival and disease frequency (the number of annual epidemics per decade. In case of epidemics of high severity (i.e., causing >30% mortality of breeding females, more than one outbreak per decade will be unsustainable for the colony and will likely lead to extinction within the next century; more than four outbreaks per decade will drive extinction to within 20 years. Such severity and frequency of avian cholera are already observed, and avian cholera might thus represent a significant threat to viability of breeding populations. However, this will depend on the mechanisms underlying avian cholera transmission, maintenance, and spread, which are currently only poorly known.

  20. Why treatment centres failed to prevent cholera deaths among Rwandan refugees in Goma, Zaire.

    Science.gov (United States)

    Siddique, A K; Salam, A; Islam, M S; Akram, K; Majumdar, R N; Zaman, K; Fronczak, N; Laston, S

    1995-02-11

    In July, 1994, in one of the worst cholera outbreaks in recent times, an estimated 12,000 Rwandan refugees died in Goma in eastern Zaire. The Vibrio cholerae strains were resistant to tetracycline and doxycycline, the commonly used drugs for cholera treatment. Despite the efforts of international organisations, which provided medical relief by establishing treatment centres in Goma, mortality from the disease was much higher than expected. In the area of Muganga camp, which had the largest concentration of refugees and where most of the medical aid organisations were active, the highest reported case-fatality ratio for a single day was 48%. The slow rate of rehydration, inadequate use of oral rehydration therapy, use of inappropriate intravenous fluids, and inadequate experience of health workers in management of severe cholera are thought to be some of the factors associated with the failure to prevent so many deaths during the epidemic. In one of the temporary treatment centres with the worst case-fatality record, our team showed that improvement of these factors could increase the odds of survival of cholera patients even in a disaster setting.

  1. Extracts of edible and medicinal plants damage membranes of Vibrio cholerae.

    Science.gov (United States)

    Sánchez, Eduardo; García, Santos; Heredia, Norma

    2010-10-01

    The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pH(in)), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism. PMID:20802077

  2. Survivability of Vibrio cholerae O1 in Cooked Rice, Coffee, and Tea

    Directory of Open Access Journals (Sweden)

    John Yew Huat Tang

    2013-01-01

    Full Text Available This study aimed to investigate the survival of Vibrio cholerae O1 in 3 types of preparation for cooked rice, Oryza sativa L., (plain rice, rice with coconut milk, and rice with ginger; coffee, Coffea canephora, (plain coffee, coffee with sugar, and coffee with sweetened condensed milk; and tea, Camellia sinensis, (plain tea, tea with sugar, and tea with sweetened condensed milk held at room temperature (27°C. The survival of V. cholerae O1 was determined by spread plate method on TCBS agar. Initial cultures of 8.00 log CFU/mL were inoculated into each food sample. After 6 h incubation, significant growth was only detected in rice with coconut milk (9.67 log CFU/mL; P<0.05. However, all 3 types of rice preparation showed significant growth of V. cholerae after 24 h (P<0.05. For coffee and tea preparations, V. cholerae survived up to 6 h in tea with condensed milk (4.72 log CFU/mL but not in similar preparation of coffee. This study showed evidence for the survivability of V. cholerae in rice, coffee, and tea. Thus, holding these food and beverages for an extended period of time at room temperature should be avoided.

  3. Specific Detection of Toxigenic Vibrio cholerae Based on in situ PCR in Combination With Flow Cytometry

    Institute of Scientific and Technical Information of China (English)

    LI ZHU; JUN-PENG CAI; QING CHEN; SHOU-YI YU

    2007-01-01

    Objective To develop an in situ PCR in combination with flow cytometry (ISPCR-FCM) for monitoring cholera toxin positive Vibrio cholerae. Methods In running this method, 4% paraformaldehyde was used to fix the Vibrio cholerae cells and 1 mg/mL lysozyme for 20 min to permeabilize the cells. Before the PCR thermal cycling, 2.5% glycerol was added into the PCR reaction mixture in order to protect the integrality of the cells. Results A length of 1037bp DNA sequence was amplified, which is specific for the cholera toxin gene (ctxAB gene). Cells subjected to ISPCR showed the presences of ctxAB gene both in epifiuorescence microscopy and in flow cytometric analysis. The specificity and sensitivity of the method were investigated. The sensitivity was relatively low (105 cells/mL), while the specificity was high. Conclusion We have successfully developed a new technique for detection of toxigenic Vibrio cholerae strains. Further study is needed to enhance its sensitivities. ISPCR-FCM shows a great promise in monitoring specific bacteria and their physiological states in environmental samples.

  4. [Multilocus sequence-typing of vibrio cholerae strains with various epidemic importance].

    Science.gov (United States)

    Mironova, L V; Afanas'ev, M V; Goldapel, E G; Balakhonov, S V

    2015-01-01

    The allele polymorphism of the housekeeping genes (dnaE, lap, recA, pgm, gyrB, cat, chi, gmd) from the Vibrio cholerae strains with different epidemic importance (n = 41) isolated in Siberia and at the Far East during the cholera pandemic VII was tested. All toxigenic strains isolated at the period of epidemic complications irrespective of time and source of isolation were characterized by the identical allele profile and belonged to the same sequence-type. Nine sequence types were detected in non-epidemic isolates. The dendrogram clustering was associated with the serogroup and in some cases with the territory and time of isolation. The structure heterogeneity of the non-toxigenic V. cholerae housekeeping genes was in most cases caused by the synonymous nucleotide replacements (Dn/Ds < 1) indicating the prevalence of the negative V. cholerae at the analyzed genome sites. The revealed distinctions in the structure of housekeeping genes of the V. cholerae with different epidemic importance can be regarded as evidence of various evolutional directions in these strain groups.

  5. Toxin-coregulated pilus-loaded microparticles as a vaccine against Vibrio cholerae O139

    Institute of Scientific and Technical Information of China (English)

    杜艳; 贾文祥; 刘莉

    2004-01-01

    @@ The cholera epidemics is an important public health problem in many developing countries. Highly effective and preventive vaccines against cholera are under investigation as alternatives to the one available presently. Much of the vaccine research focuses on colonization factors. Colonization of a human by the Vibrio cholerae (V. cholerae Ol strain is mediated by toxin-coregulated pilus (TCP), 1 which was shown to play a role in the infant mouse cholera model and subsequently in human volunteers. 2 TCP-loaded vaccines could potentially provide cross-protection among experimental strains. Data have indicated that poly (D,L-lactide)-polyethylene glycol copolymer (PELA)microparticles loaded antigens were strongly immunogenic, 3 and that these microparticles served as an effective delivery system for a single dose of vaccine. 4Microparticle formulation could represent the next generation of vaccines, as they are highly effective at delivery of vaccines, thus requiring fewer doses. 5 We prepared PELA microparticles loaded with TCP for testing as a vaccine; their targeting distributions were identified and related immune responses were analyzed.

  6. Modeling the Epidemiology of Cholera to Prevent Disease Transmission in Developing Countries

    Science.gov (United States)

    MUKANDAVIRE, ZINDOGA; MORRIS, J. GLENN

    2015-01-01

    Cholera remains an important global cause of morbidity and mortality, which is capable of causing periodic epidemic disease. A number of mathematical models have been developed to help in understanding the dynamics of cholera outbreaks and for use as a tool in planning interventions, including vaccination campaigns. We have explored the utility of models in assessing the spread of cholera in the recent epidemics in Zimbabwe and Haiti. In both instances, a mathematical model was formulated and fitted to cumulative cholera cases to estimate the basic reproductive number ℜ0, and the partial reproductive numbers reflecting potential differences in environmental-to-human versus human-to-human transmission were quantified. In Zimbabwe, estimated ℜ0 for the epidemic using aggregated data at the national level was 1.15; in Haiti, it was 1.55. However, when calculated at a provincial/departmental level, estimated basic reproductive numbers were highly heterogeneous, with a range of 1.11 to 2.72 in Zimbabwe and 1.06 to 2.63 in Haiti. Our models suggest that the underlying patterns of cholera transmission varied widely from region to region, with a corresponding variation in the amenability of outbreaks to control measures such as immunization. These data underscore the heterogeneity of transmission dynamics, potentially linked to differences in environment, socio-economic conditions, and cultural practices. They also highlight the potential utility of these types of models in guiding development of public health intervention strategies. PMID:26185087

  7. Global climate and infectious disease: The cholera paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, R.R. [Univ. of Maryland Biotechnology Inst., College Park, MD (United States)

    1996-12-20

    Historically, infectious diseases have had a profound effect on human populations, including their evolution and cultural development. Despite significant advances in medical science, infectious diseases continue to impact human populations in many parts of the world. Emerging diseases are considered to be those infections that either are newly appearing in the population or are rapidly increasing in incidence or expanding in geographic range. Emergence of disease is not a simple phenomenon, mainly because infectious diseases are dynamic. Most new infections are not caused by truly new pathogens but are microorganisms (viruses, bacteria, fungi, protozoa, and helminths) that find a new way to enter a susceptible host and are newly recognized because of recently developed, sensitive techniques. Human activities drive emergence of disease and a variety of social, economic, political, climatic, technological, and environmental factors can shape the pattern of a disease and influence its emergence into populations. For example, travel affects emergence of disease, and human migrations have been the main source of epidemics throughout history. Trade caravans, religious pilgrimage, and military campaigns facilitated the spread of plague, smallpox, and cholera. Global travel is a fact of modern life and, equally so, the continued evolution of microorganisms; therefore, new infections will continue to emerge, and known infections will change in distribution, frequency, and severity. 88 refs., 1 fig.

  8. Real-time modelling used for outbreak management during a cholera epidemic, Haiti, 2010-2011.

    Science.gov (United States)

    Abrams, J Y; Copeland, J R; Tauxe, R V; Date, K A; Belay, E D; Mody, R K; Mintz, E D

    2013-06-01

    The emergence of epidemic cholera in post-earthquake Haiti portended a public health disaster of uncertain magnitude. In order to coordinate relief efforts in an environment with limited healthcare infrastructure and stretched resources, timely and realistic projections of the extent of the cholera outbreak were crucial. Projections were shared with Government and partner organizations beginning 5 days after the first reported case and were updated using progressively more advanced methods as more surveillance data became available. The first projection estimated that 105 000 cholera cases would occur in the first year. Subsequent projections using different methods estimated up to 652 000 cases and 163 000-247 000 hospitalizations during the first year. Current surveillance data show these projections to have provided reasonable approximations of the observed epidemic. Providing the real-time projections allowed Haitian ministries and external aid organizations to better plan and implement response measures during the evolving epidemic.

  9. Repair of ultraviolet light-induced DNA damage in cholera bacteriophages

    Energy Technology Data Exchange (ETDEWEB)

    Palit, B.N.; Das, G.; Das, J. (Indian Inst. of Chemical Biology, Calcutta. Dept. of Biophysics)

    1983-08-01

    DNA repair-proficient and -deficient strains of Vibrio cholerae were used to examine host cell reactivation, Weigle reactivation and photoreactivation of u.v.-irradiated cholera bacteriophages. U.v. light-induced DNA damage in phages of different morphological and serological groups could be efficiently photoreactivated. Host cell reactivation of irradiated phages of different groups was different on the same indicator host. Phage phi149 was the most sensitive, and phi138 the most resistant to u.v. irradiation. While phi138 showed appreciable host cell reactivation, this was minimal for phi149. Attempts to demonstrate Weigle reactivation of u.v.-irradiated cholera phages were not successful, although u.v.-induced filamentation of host cells was observed.

  10. Repair of ultraviolet light-induced DNA damage in cholera bacteriophages

    International Nuclear Information System (INIS)

    DNA repair-proficient and -deficient strains of Vibrio cholerae were used to examine host cell reactivation, Weigle reactivation and photoreactivation of u.v.-irradiated cholera bacteriophages. U.v. light-induced DNA damage in phages of different morphological and serological groups could be efficiently photoreactivated. Host cell reactivation of irradiated phages of different groups was different on the same indicator host. Phage phi149 was the most sensitive, and phi138 the most resistant to u.v. irradiation. While phi138 showed appreciable host cell reactivation, this was minimal for phi149. Attempts to demonstrate Weigle reactivation of u.v.-irradiated cholera phages were not successful, although u.v.-induced filamentation of host cells was observed. (author)

  11. Effect of ionizing radiation on fresh vegetables artificially contaminated with Vibrio cholerae

    International Nuclear Information System (INIS)

    Lettuce, cabbage and celery were artificially contaminated with Vibrio cholerae El Tor 01 Inaba, and irradiated at 0.50, 0.75 and 1.00 kGy. Non-irradiated samples were used as controls. The effect of irradiation was measured during 7-days storage under refrigeration, from the viewpoints of microbiological (MPN), nutritional (Vitamin C content), and sensory quality. Irradiation proved to be an effective technique to eliminate V. cholerae in fresh vegetables. Doses of less than 0.75 kGy were sufficient to eliminate an initial contamination of 105 cells/g of V. cholerae; neither sensory properties or nutritional quality (Vitamin C content) were adversely affected by the treatment. The cost of irradiating the vegetables at 0.5 kGy under the conditions of the study was US$ 0.131, 0.067 and 0.445 per unit of lettuce, cabbage and celery, respectively. (author)

  12. Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibro cholerae

    International Nuclear Information System (INIS)

    A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bsub(s), lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay. (orig.)

  13. Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibro cholerae

    Energy Technology Data Exchange (ETDEWEB)

    Das, G.; Das, J. (Indian Inst. of Chemical Biology, Calcutta. Biophysics Div.)

    1983-04-01

    A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bsub(s), lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay.

  14. Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibrio cholerae.

    Science.gov (United States)

    Das, G; Das, J

    1983-04-01

    A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bs, lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay.

  15. The Costs of Climate Change: A Study of Cholera in Tanzania

    DEFF Research Database (Denmark)

    Trærup, Sara Lærke Meltofte; Ortiz, Ramon A.; Markandya, Anil

    2011-01-01

    Increased temperatures and changes in rainfall patterns as a result of climate change are widely recognized to entail potentially serious consequences for human health, including an increased risk of diarrheal diseases. This study integrates historical data on temperature and rainfall with the bu......Increased temperatures and changes in rainfall patterns as a result of climate change are widely recognized to entail potentially serious consequences for human health, including an increased risk of diarrheal diseases. This study integrates historical data on temperature and rainfall...... risk of cholera increases by 15 to 29 percent. Based on the modeling results, we project the number and costs of additional cases of cholera that can be attributed to climate change by 2030 in Tanzania for a 1 and 2 degree increase in temperatures, respectively. The total costs of cholera attributable...

  16. Antagonistic Activity of Probiotic Organism Against Vibrio cholerae and Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Vidya, R.

    2010-01-01

    Full Text Available The microbes are useful in many ways in the modern world. Probiotics one of them, which refers to, acid adherence bacteria in the intestinal cells, are able to survive at low pH and produce large amount of lactic acid. The present investigation deals with the antagonistic activity of Lactobacillus acidophilus organism against pathogens. The organism was isolated from the curd sample. Identification of bacteria was done by various biochemical testing. The present study revealed that L. acidophilus inhibits Vibrio cholerae more efficiently than Streptococcus pneumoniae and Shigella dysentriae. When L. acidophilus and V. cholerae were grown together, L. acidophilus dominated the growth and competitively inhibited the growth of V. cholerae. L. acidophilus was also found to inhibit Cryptococcus neoformans.

  17. The Effect of Predators on Cholera Biofilms: If it Lyses, We Can Smash It

    Science.gov (United States)

    Kalziqi, Arben; Bernardy, Eryn; Thomas, Jacob; Ratcliff, Will; Hammer, Brian; Yunker, Peter

    Many microbes form biofilms--dense clumps of cells and proteins--on surfaces. Biofilms are complex communities that facilitate the study of biological competition (e.g., two types of microbes may compete to form a biofilm in the same location) and interesting physics (e.g., the source of a biofilm's rigidity). Vibrio cholerae can produce biofilms which have a network-like structure--however, cholera can be genetically engineered to kill other cholera with different genotypes, which leaves behind a structureless ``slime'' rather than such a biofilm. Through mechanical creep testing of both predator-prey and non-predator populations, we found that the predator-prey population responds viscously and decreases in height with repeated compression, whereas the non-predator population responds elastically and maintains its original height. The current work suggests that cell lysis after killing disrupts biofilm formation, preventing microbial colonies from forming rigid networks.

  18. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    Science.gov (United States)

    Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

    2014-02-01

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

  19. ToxR of Vibrio cholerae affects biofilm, rugosity and survival with Acanthamoeba castellanii

    Directory of Open Access Journals (Sweden)

    Valeru Soni P

    2012-01-01

    Full Text Available Abstract Background Vibrio cholerae causes the diarrheal disease cholera and utilizes different survival strategies in aquatic environments. V. cholerae can survive as free-living or in association with zooplankton and can build biofilm and rugose colonies. The bacterium expresses cholera toxin (CT and toxin-coregulated pilus (TCP as the main virulence factors. These factors are co-regulated by a transcriptional regulator ToxR, which modulates expression of outer membrane proteins (OmpU and (OmpT. The aims of this study were to disclose the role of ToxR in expression of OmpU and OmpT, biofilm and rugose colony formation as well as in association with the free-living amoeba Acanthamoeba castellanii at different temperatures. Results The toxR mutant V. cholerae produced OmpT, significant biofilm and rugose colonies compared to the wild type that produced OmpU, decreased biofilm and did not form rugoes colonies at 30°C. Interestingly, neither the wild type nor toxR mutant strain could form rugose colonies in association with the amoebae. However, during the association with the amoebae it was observed that A. castellanii enhanced survival of V. cholerae wild type compared to toxR mutant strain at 37°C. Conclusions ToxR does seem to play some regulatory role in the OmpT/OmpU expression shift, the changes in biofilm, rugosity and survival with A. castellanii, suggesting a new role for this regulatory protein in the environments.

  20. Assessing clonal correlation of epidemic Vibrio cholerae isolates during 2011 in 16 provinces of Iran.

    Science.gov (United States)

    Hajia, Massoud; Rahbar, Mohamad; Farzami, Marjan Rahnamye; Asl, Hossein Masoumi; Dolatyar, Alireza; Imani, Mohsen; Saburian, Roghieh; Mafi, Moharam; Bakhshi, Bita

    2015-03-01

    A total of 1,187 Vibrio cholerae isolates were received during 2011 cholera outbreaks from 16 provinces in different geographical location to Iranian reference Health laboratory. A random selection was performed, and 61 isolates were subjected to further investigations. Cholera cases were come up from May with nine cases and reached to its maximum rate at August (57 cases) and continued to October after which a fall occurred in September. All of the isolates were susceptible to three antimicrobial agents including ciprofloxacin, cefixime, and ampicillin. The highest rate of resistance was seen to nalidixic acid (96.7 %) and co-trimoxazole (91.8 %). Clonality of isolates was investigated through genotyping by PFGE method. A total of seven pulsotypes were obtained from 61 isolates under study. The pulsotypes were highly related with only 1-3 bands differences. Three pulsotypes (PT5, PT6, and PT7) constituted 93.4 % of total isolates. One environmentally isolated strain showed distinct pattern from clinical specimens. This strain although had no any evidence in identified cholera infections, highlighted selecting more environmental specimens in any future outbreaks as long as human samples. In conclusion, emergence and dominance of Ogawa serotypes after about 7 years in Iran are alarming due to fear of import of new V. cholerae clones from out of the country. Approximately, one third of patients in 2011 cholera outbreak in Iran were of Afghan or Pakistani nationality which makes the hypothesis of import of Ogawa serotype strains from neighboring countries more documented and signifies the need to monitor and protect the boundaries.

  1. The Role Of The Aquatic Reservoir In Long-Term Cholera Dynamics

    Science.gov (United States)

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

    2010-12-01

    A novel class of models for Cholera epidemics is described, where the dynamics of the water volume defining the aquatic reservoir of pathogens accessible to a given local community is explicitly considered. In particular, we study how the hydrologic dynamics affects the fluctuations of Vibrio cholerae concentrations in the local reservoir thus driving the evolution of the epidemics at local scales. The novelty of the approach lies in the coupling of an input-output hydrologic dynamics with an epidemiological model which tracks susceptibles, infected and recovered individuals, jointly with bacterial concentrations. Reservoir volumes fluctuating over time indeed control the concentrations of Vibrio cholerae: one of the most common mechanisms of cholera insurgence in endemic regions is, in fact, spring water drought. Here we consider a spatially implicit framework, in order to distinguish the contribution of local dynamics to cholera insurgence at community scales. Our main goal is to investigate the relation between yearly water volume oscillations and long-term trajectories of cholera infection. To this end we take into account a monsoonal fluctuation, with one summer peak in the water input. This simple addition allows us to derive relationships between hydrologic regimes and the epidemiological behavior of the system. Since most of the numerical values of model parameters can be reliably drawn from the literature on the subject, this method allows us to concentrate on significant but still uncertain quantities and associate different ranges of parameter values to different model behaviors which need to be clearly differentiated . Our analysis provides information on the characteristic value of the model parameters for real case studies, comparing simulations and real time series. The model can be very useful in particular for the inference of the intensity of the disease, expressed in terms of the basic reproductive number.

  2. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    International Nuclear Information System (INIS)

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia

  3. Haiti's progress in achieving its 10-year plan to eliminate cholera: hidden sickness cannot be cured.

    Science.gov (United States)

    Koski-Karell, Victoria; Farmer, Paul E; Isaac, Benito; Campa, Elizabeth M; Viaud, Loune; Namphy, Paul C; Ternier, Ralph; Ivers, Louise C

    2016-01-01

    Since the beginning of the cholera epidemic in Haiti 5 years ago, the prevalence of this deadly water-borne disease has fallen far below the initial rates registered during its explosive outset. However, cholera continues to cause extensive suffering and needless deaths across the country, particularly among the poor. The urgent need to eliminate transmission of cholera persists: compared to the same period in 2014, the first 4 months of 2015 saw three times the number of cholera cases. Drawing upon epidemiology, clinical work (and clinical knowledge), policy, ecology, and political economy, and informed by ethnographic data collected in a rural area of Haiti called Bocozel, this paper evaluates the progress of the nation's 10-year Plan for the Elimination of Cholera. Bocozel is a rice-producing region where most people live in extreme poverty. The irrigation network is decrepit, the land is prone to environmental shocks, fertilizer is not affordable, and the government's capacity to assist farmers is undermined by resource constraints. When peasants do have rice to sell, the price of domestically grown rice is twice that of US-imported rice. Canal water is not only used to irrigate thousands of acres of rice paddies and sustain livestock, but also to bathe, wash, and play, while water from wells, hand pumps, and the river is used for drinking, cooking, and bathing. Only one out of the three government-sponsored water treatment stations in the research area is still functional and utilized by those who can afford it. Latrines are scarce and often shared by up to 30 people; open defecation remains common. Structural vulnerabilities cut across all sectors - not just water, sanitation, health care, and education, but agriculture, environment, (global and local) commerce, transportation, and governance as well. These are among the hidden sicknesses that impede Haiti and its partners' capacity to eliminate cholera. PMID:27307774

  4. Spatio-temporal dynamics of cholera during the first year of the epidemic in Haiti.

    Directory of Open Access Journals (Sweden)

    Jean Gaudart

    Full Text Available BACKGROUND: In October 2010, cholera importation in Haiti triggered an epidemic that rapidly proved to be the world's largest epidemic of the seventh cholera pandemic. To establish effective control and elimination policies, strategies rely on the analysis of cholera dynamics. In this report, we describe the spatio-temporal dynamics of cholera and the associated environmental factors. METHODOLOGY/PRINCIPAL FINDINGS: Cholera-associated morbidity and mortality data were prospectively collected at the commune level according to the World Health Organization standard definition. Attack and mortality rates were estimated and mapped to assess epidemic clusters and trends. The relationships between environmental factors were assessed at the commune level using multivariate analysis. The global attack and mortality rates were 488.9 cases/10,000 inhabitants and 6.24 deaths/10,000 inhabitants, respectively. Attack rates displayed a significantly high level of spatial heterogeneity (varying from 64.7 to 3070.9 per 10,000 inhabitants, thereby suggesting disparate outbreak processes. The epidemic course exhibited two principal outbreaks. The first outbreak (October 16, 2010-January 30, 2011 displayed a centrifugal spread of a damping wave that suddenly emerged from Mirebalais. The second outbreak began at the end of May 2011, concomitant with the onset of the rainy season, and displayed a highly fragmented epidemic pattern. Environmental factors (river and rice fields: p<0.003 played a role in disease dynamics exclusively during the early phases of the epidemic. CONCLUSION: Our findings demonstrate that the epidemic is still evolving, with a changing transmission pattern as time passes. Such an evolution could have hardly been anticipated, especially in a country struck by cholera for the first time. These results argue for the need for control measures involving intense efforts in rapid and exhaustive case tracking.

  5. Haiti's progress in achieving its 10-year plan to eliminate cholera: hidden sickness cannot be cured.

    Science.gov (United States)

    Koski-Karell, Victoria; Farmer, Paul E; Isaac, Benito; Campa, Elizabeth M; Viaud, Loune; Namphy, Paul C; Ternier, Ralph; Ivers, Louise C

    2016-01-01

    Since the beginning of the cholera epidemic in Haiti 5 years ago, the prevalence of this deadly water-borne disease has fallen far below the initial rates registered during its explosive outset. However, cholera continues to cause extensive suffering and needless deaths across the country, particularly among the poor. The urgent need to eliminate transmission of cholera persists: compared to the same period in 2014, the first 4 months of 2015 saw three times the number of cholera cases. Drawing upon epidemiology, clinical work (and clinical knowledge), policy, ecology, and political economy, and informed by ethnographic data collected in a rural area of Haiti called Bocozel, this paper evaluates the progress of the nation's 10-year Plan for the Elimination of Cholera. Bocozel is a rice-producing region where most people live in extreme poverty. The irrigation network is decrepit, the land is prone to environmental shocks, fertilizer is not affordable, and the government's capacity to assist farmers is undermined by resource constraints. When peasants do have rice to sell, the price of domestically grown rice is twice that of US-imported rice. Canal water is not only used to irrigate thousands of acres of rice paddies and sustain livestock, but also to bathe, wash, and play, while water from wells, hand pumps, and the river is used for drinking, cooking, and bathing. Only one out of the three government-sponsored water treatment stations in the research area is still functional and utilized by those who can afford it. Latrines are scarce and often shared by up to 30 people; open defecation remains common. Structural vulnerabilities cut across all sectors - not just water, sanitation, health care, and education, but agriculture, environment, (global and local) commerce, transportation, and governance as well. These are among the hidden sicknesses that impede Haiti and its partners' capacity to eliminate cholera.

  6. Cystic Fibrosis Heterozygote Resistance to Cholera Toxin in the Cystic Fibrosis Mouse Model

    Science.gov (United States)

    Gabriel, Sherif E.; Brigman, Kristen N.; Koller, Beverly H.; Boucher, Richard C.; Stutts, M. Jackson

    1994-10-01

    The effect of the number of cystic fibrosis (CF) alleles on cholera toxin (CT)-induced intestinal secretion was examined in the CF mouse model. CF mice that expressed no CF transmembrane conductance regulator (CFTR) protein did not secrete fluid in response to CT. Heterozygotes expressed 50 percent of the normal amount of CFTR protein in the intestinal epithelium and secreted 50 percent of the normal fluid and chloride ion in response to CT. This correlation between CFTR protein and CT-induced chloride ion and fluid secretion suggests that CF heterozygotes might possess a selective advantage of resistance to cholera.

  7. Molecular epidemiology of Vibrio cholerae associated with flood in Brahamputra River valley, Assam, India.

    Science.gov (United States)

    Bhuyan, Soubhagya K; Vairale, Mohan G; Arya, Neha; Yadav, Priti; Veer, Vijay; Singh, Lokendra; Yadava, Pramod K; Kumar, Pramod

    2016-06-01

    Cholera is often caused when drinking water is contaminated through environmental sources. In recent years, the drastic cholera epidemics in Odisha (2007) and Haiti (2010) were associated with natural disasters (flood and Earthquake). Almost every year the state of Assam India witnesses flood in Brahamputra River valley during reversal of wind system (monsoon). This is often followed by outbreak of diarrheal diseases including cholera. Beside the incidence of cholera outbreaks, there is lack of experimental evidence for prevalence of the bacterium in aquatic environment and its association with cholera during/after flood in the state. A molecular surveillance during 2012-14 was carried out to study prevalence, strain differentiation, and clonality of Vibrio cholerae in inland aquatic reservoirs flooded by Brahamputra River in Assam. Water samples were collected, filtered, enriched in alkaline peptone water followed by selective culturing on thiosulfate bile salt sucrose agar. Environmental isolates were identified as V. cholerae, based on biochemical assays followed by sero-grouping and detailed molecular characterization. The incidence of the presence of the bacterium in potable water sources was higher after flood. Except one O1 isolate, all of the strains were broadly grouped under non-O1/non-O139 whereas some of them did have cholera toxin (CT). Surprisingly, we have noticed Haitian ctxB in two non-O1/non-O139 strains. MLST analyses based on pyrH, recA and rpoA genes revealed clonality in the environmental strains. The isolates showed varying degree of antimicrobial resistance including tetracycline and ciprofloxacin. The strains harbored the genetic elements SXT constins and integrons responsible for multidrug resistance. Genetic characterization is useful as phenotypic characters alone have proven to be unsatisfactory for strain discrimination. An assurance to safe drinking water, sanitation and monitoring of the aquatic reservoirs is of utmost importance for

  8. Contribution of non-immune phagocytes to protection of mice against Vibrio cholerae

    International Nuclear Information System (INIS)

    Bacterial kinetics of Vibrio cholerae 569B in the local infection of mice was examined after the γ-ray-irradiation or the treatment with carrageenan. In the control mice, bacterial number decreased exponentially. In the mice treated with carrageenan gave similar tendency. In the irradiated mice, however, decrease in bacterial number was not as significant and the clearance was never observed. From these results, it is concluded that the protection against V. cholerae local infection depends mainly on polymorphonuclear cells in the early phase. (author)

  9. Molecular epidemiology of Vibrio cholerae associated with flood in Brahamputra River valley, Assam, India.

    Science.gov (United States)

    Bhuyan, Soubhagya K; Vairale, Mohan G; Arya, Neha; Yadav, Priti; Veer, Vijay; Singh, Lokendra; Yadava, Pramod K; Kumar, Pramod

    2016-06-01

    Cholera is often caused when drinking water is contaminated through environmental sources. In recent years, the drastic cholera epidemics in Odisha (2007) and Haiti (2010) were associated with natural disasters (flood and Earthquake). Almost every year the state of Assam India witnesses flood in Brahamputra River valley during reversal of wind system (monsoon). This is often followed by outbreak of diarrheal diseases including cholera. Beside the incidence of cholera outbreaks, there is lack of experimental evidence for prevalence of the bacterium in aquatic environment and its association with cholera during/after flood in the state. A molecular surveillance during 2012-14 was carried out to study prevalence, strain differentiation, and clonality of Vibrio cholerae in inland aquatic reservoirs flooded by Brahamputra River in Assam. Water samples were collected, filtered, enriched in alkaline peptone water followed by selective culturing on thiosulfate bile salt sucrose agar. Environmental isolates were identified as V. cholerae, based on biochemical assays followed by sero-grouping and detailed molecular characterization. The incidence of the presence of the bacterium in potable water sources was higher after flood. Except one O1 isolate, all of the strains were broadly grouped under non-O1/non-O139 whereas some of them did have cholera toxin (CT). Surprisingly, we have noticed Haitian ctxB in two non-O1/non-O139 strains. MLST analyses based on pyrH, recA and rpoA genes revealed clonality in the environmental strains. The isolates showed varying degree of antimicrobial resistance including tetracycline and ciprofloxacin. The strains harbored the genetic elements SXT constins and integrons responsible for multidrug resistance. Genetic characterization is useful as phenotypic characters alone have proven to be unsatisfactory for strain discrimination. An assurance to safe drinking water, sanitation and monitoring of the aquatic reservoirs is of utmost importance for

  10. Clonal relationship among Vibrio cholerae O1 El Tor strains isolated in Somalia.

    Science.gov (United States)

    Scrascia, Maria; Pugliese, Nicola; Maimone, Francesco; Mohamud, Kadigia A; Grimont, Patrick A D; Materu, Sadiki F; Pazzani, Carlo

    2009-03-01

    One hundred and three Vibrio cholerae O1 strains, selected to represent the cholera outbreaks which occurred in Somalia in 1998-1999, were characterized by random amplified polymorphic DNA patterns, ribotyping, and antimicrobial susceptibility. All strains showed a unique amplified DNA pattern and 2 closely related ribotypes (B5a and B8a), among which B5a was the more frequently identified. Ninety-one strains were resistant to ampicillin, chloramphenicol, spectinomycin, streptomycin, sulfamethoxazole, and trimethoprim, conferred, except for spectinomycin, by a conjugative plasmid IncC. These findings indicated that the group of strains active in Somalia in the late 1990s had a clonal origin.

  11. Enterotoxin production by Vibrio cholerae and Vibrio mimicus grown in continuous culture with microbial cell recycle.

    OpenAIRE

    Spira, W M; Fedorka-Cray, P. J.

    1983-01-01

    We have examined the effect of complete cell recycle on the production of cholera toxin (CT) by Vibrio cholerae and CT-like toxin by Vibrio mimicus in continuous culture fermentations. Complete cell recycle was obtained by filtering culture fluids through Amicon hollow fibers with an exclusion limit of 100,000 daltons (H1P100-20) and returning the concentrated cell slurry to the fermentor. A single 1-liter laboratory fermentor system modified with this recycle loop was capable of producing ov...

  12. Occurrence of Vibrio cholerae non 01 and their dispersion phenomena in the coastal waters at Mangalore

    Digital Repository Service at National Institute of Oceanography (India)

    Sreeja, S.; Raveendran, O.

    incidence of V. cholerae non 01 along the coastal areas of Mangalore. The significance of the occurrence of V. cholerae non 01 is that the frequent isolation of these organisms from an ecosystem indicates a possible health hazard. The influence..., PA., Weaver, R.E. & Hollis, D.G. (1980) Ann. Rev-Microbiol, 3, p.341 Colwell, R.R. (1984) Vibrios in the envt, p.l (John Wiley & Sons, New York) Colwell, R.R. & Kaper, J. (1997) Science, p.394 Iyer, T.S.G., Varma, P.RG., Agnes J. M. & Zacharia, S...

  13. EVALUASI MEDIUM PENGAYAAN Vibrio cholerae UNTUK DIAGNOSIS KOLERA MENGGUNAKAN IMMUNOCHROMATOGRAPHIC STRIP TEST

    Directory of Open Access Journals (Sweden)

    Kambang Sariadji

    2013-05-01

    Full Text Available Abstract. Vibrio cholerae strains are capable of causing  outbreak cholera in developing country with poor sanitation and hygiene .Conventional culture methods currently available for detection of V. cholerae 01 takes 3 – 5 days. Other diagnostic tools are by using rapid immunochromatographic strip test for controlling and preventing the spreading of cholera outbreak. This method has limitation in detection of V.cholerae O1, especially under 105 cfu/mL. Furthermore rapid method can be improved by  enrichment media and incubation in 37° C for 6 – 8 hours. The aims of research are to analyse enrichments media in increasingl V.cholerae O1, and it’s to improve the finding of the laboratory diagnosis of cholera cases. The research was conducted at the Laboratory of Bacteriology, Center of Biomedical and Basic Technology of Health National Institute of Health Research and Development (NIHRD from January - July 2011. Medium evaluation was done by making serial dilutions of Vibrio cholerae O1 from 107-101 cfu / ml  inoculated into three mediums: alkaline peptone water, bismuth sulfite, and gelatin phosphate salt broth medium. Then were incubated 37°C for 8 hours and every two hours was tested by immunochromatographic strip test. The data analysis to determine treatment and individual differences  each group was done by one way ANOVA test. The results showed that alkali peptone water are better than gelatine phosphate salt broth and bismuth sulfite in increasing V.cholerae O1, p.value 0.000 means significant different. Meanwhile from 24 samples dilutions which were inoculated in three enrichment media, and detected by rapid immunochromatographic in every 2 hours for 8 hours showed positive result in enrichments media are 17 samples for alkali peptone water, 13 samples for gelatine phosphate salt broth  and 8 samples for bismuth sulfite. Key Words : V.Cholerae, Enrichment Media, Immunochromatographic strip test   Abstrak. Vibrio cholerae O1

  14. Enhanced interaction of Vibrio cholerae virulence regulators TcpP and ToxR under oxygen-limiting conditions.

    Science.gov (United States)

    Fan, Fenxia; Liu, Zhi; Jabeen, Nusrat; Birdwell, L Dillon; Zhu, Jun; Kan, Biao

    2014-04-01

    Vibrio cholerae is the causative agent of the diarrheal disease cholera. The ability of V. cholerae to colonize and cause disease requires the intricately regulated expression of a number of virulence factors during infection. One of the signals sensed by V. cholerae is the presence of oxygen-limiting conditions in the gut. It has been shown that the virulence activator AphB plays a key role in sensing low oxygen concentrations and inducing the transcription of another key virulence activator, TcpP. In this study, we used a bacterial two-hybrid system to further examine the effect of oxygen on different virulence regulators. We found that anoxic conditions enhanced the interaction between TcpP and ToxR, identified as the first positive regulator of V. cholerae virulence genes. We further demonstrated that the TcpP-ToxR interaction was dependent on the primary periplasmic protein disulfide formation enzyme DsbA and cysteine residues in the periplasmic domains of both ToxR and TcpP. Furthermore, we showed that in V. cholerae, an interaction between TcpP and ToxR is important for virulence gene induction. Under anaerobic growth conditions, we detected ToxR-TcpP heterodimers, which were abolished in the presence of the reducing agent dithiothreitol. Our results suggest that V. cholerae may sense intestinal anoxic signals by multiple components to activate virulence.

  15. The Vibrio cholerae Pst2 phosphate transport system is upregulated in biofilms and contributes to biofilm-induced hyperinfectivity.

    Science.gov (United States)

    Mudrak, Benjamin; Tamayo, Rita

    2012-05-01

    Vibrio cholerae is the causative agent of the deadly diarrheal disease cholera. As part of its life cycle, V. cholerae persists in marine environments, where it forms surface-attached communities commonly described as biofilms. Evidence indicates that these biofilms constitute the infectious form of the pathogen during outbreaks. Previous work has shown that biofilm-derived V. cholerae cells, even when fully dispersed from the biofilm matrix, are vastly more infectious than planktonic (free-living) cells. Here, we sought to identify factors that contribute to biofilm-induced hyperinfectivity in V. cholerae, and we present evidence for one aspect of the molecular basis of this phenotype. We identified proteins upregulated during growth in biofilms and determined their contributions to the hyperinfectivity phenotype. We found that PstS2, the periplasmic component of the Pst2 phosphate uptake system, was enriched in biofilms. Another gene in the pst2 locus was transcriptionally upregulated in biofilms. Using the infant mouse model, we found that mutation of two pst2 components resulted in impaired colonization. Importantly, deletion of the Pst2 inner membrane complex caused a greater colonization defect after growth in a biofilm compared to shaking culture. Based on these data, we propose that V. cholerae cells in biofilms upregulate the Pst2 system and therefore gain an advantage upon entry into the host. Further characterization of factors contributing to biofilm-induced hyperinfectivity in V. cholerae will improve our understanding of the transmission of the bacteria from natural aquatic habitats to the human host.

  16. Characterization of Vibrio cholerae bacteriophages isolated from the environmental waters of the Lake Victoria region of Kenya.

    Science.gov (United States)

    Maina, Alice Nyambura; Mwaura, Francis B; Oyugi, Julius; Goulding, David; Toribio, Ana L; Kariuki, Samuel

    2014-01-01

    Over the last decade, cholera outbreaks have become common in some parts of Kenya. The most recent cholera outbreak occurred in Coastal and Lake Victoria region during January 2009 and May 2010, where a total of 11,769 cases and 274 deaths were reported by the Ministry of Public Health and Sanitation. The objective of this study is to isolate Vibrio cholerae bacteriophages from the environmental waters of the Lake Victoria region of Kenya with potential for use as a biocontrol for cholera outbreaks. Water samples from wells, ponds, sewage effluent, boreholes, rivers, and lakes of the Lake Victoria region of Kenya were enriched for 48 h at 37 °C in broth containing a an environmental strain of V. cholerae. Bacteriophages were isolated from 5 out of the 42 environmental water samples taken. Isolated phages produced tiny, round, and clear plaques suggesting that these phages were lytic to V. cholerae. Transmission electron microscope examination revealed that all the nine phages belonged to the family Myoviridae, with typical icosahedral heads, long contractile tails, and fibers. Head had an average diameter of 88.3 nm and tail of length and width 84.9 and 16.1 nm, respectively. Vibriophages isolated from the Lake Victoria region of Kenya have been characterized and the isolated phages may have a potential to be used as antibacterial agents to control pathogenic V. cholerae bacteria in water reservoirs.

  17. Retrospective Analysis of Serotype Switching of Vibrio cholerae O1 in a Cholera Endemic Region Shows It Is a Non-random Process

    Science.gov (United States)

    Karlsson, Stefan L.; Thomson, Nicholas; Mutreja, Ankur; Connor, Thomas; Sur, Dipika; Ali, Mohammad; Clemens, John; Dougan, Gordon; Holmgren, Jan; Lebens, Michael

    2016-01-01

    Genomic data generated from clinical Vibrio cholerae O1 isolates collected over a five year period in an area of Kolkata, India with seasonal cholera outbreaks allowed a detailed genetic analysis of serotype switching that occurred from Ogawa to Inaba and back to Ogawa. The change from Ogawa to Inaba resulted from mutational disruption of the methyltransferase encoded by the wbeT gene. Re-emergence of the Ogawa serotype was found to result either from expansion of an already existing Ogawa clade or reversion of the mutation in an Inaba clade. Our data suggests that such transitions are not random events but rather driven by as yet unidentified selection mechanisms based on differences in the structure of the O1 antigen or in the serotype-determining wbeT gene. PMID:27706170

  18. Action of cholera toxin in the intestinal epithelial cells

    International Nuclear Information System (INIS)

    The primary event in the action of cholera toxin on the isolated chick intestinal epithelial cell is its interaction with a large number of high affinity binding sites in the cell membrane. Binding of 125I-labeled toxin is rapid, temperature-dependent, reversible, and saturable over a wide range of concentrations and includes only a small contribution from nonspecific sites. A characteristic lag phase of 10 min occurs following the complete binding of toxin before any increase in cellular cAMP levels can be detected. The response (elevation of cellular cAMP) is linear with time for 40 to 50 min and causes a six- to eight-fold increase over control levels (10 to 15 picomole cAMP/mg cellular protein) at steady state. cAMP and agents that increase cAMP production inhibit Cl--independent Na+ influx into the isolated enterocytes whereas chlorpromazine (CPZ) which completely abolishes toxin-induced elevation of cAMP both reverses and prevents the cAMP-mediated inhibition of Na+ entry. Correlation between cellular cAMP levels and the magnitude of Na+ influx provides evidence for a cAMP-mediated control of intestinal Na+ uptake, which may represent the mechanistic basis for the antiabsorptive effect of CT on Na+ during induction of intestinal secretion. The effect of cAMP on Na+ but not Cl- influx preparations can be partially explained in terms of a cAMP-regulated Na+/H+ neutral exchange system. Data on the coupling relationship between Na+ transport and the intra- and extracellular pH in the enterocytes show that an amiloride-sensitive electroneutral Na+/H+ exchange process occurs. This coupling between Na+ and H+ is partially inhibited by CT and dbcAMP, suggesting that the Na+/H+ exchange may be a cAMP-regulated process. 31 references, 32 figures, 5 tables

  19. Enterotoxigenicity of Mature 45-Kilodalton and Processed 35-Kilodalton Forms of Hemagglutinin Protease Purified from a Cholera Toxin Gene-Negative Vibrio cholerae Non-O1, Non-O139 Strain

    OpenAIRE

    Ghosh, A; Saha, D. R.; Hoque, K. M.; Asakuna, M.; Yamasaki, S.; Koley, H; Das, S. S.; Chakrabarti, M K; Pal, A.

    2006-01-01

    Cholera toxin gene-negative Vibrio cholerae non-O1, non-O139 strain PL-21 is the etiologic agent of cholera-like syndrome. Hemagglutinin protease (HAP) is one of the major secretory proteins of PL-21. The mature 45-kDa and processed 35-kDa forms of HAP were purified in the presence and absence of EDTA from culture supernatants of PL-21. Enterotoxigenicities of both forms of HAP were tested in rabbit ileal loop (RIL), Ussing chamber, and tissue culture assays. The 35-kDa HAP showed hemorrhagic...

  20. Protection from annual flooding is correlated with increased cholera prevalence in Bangladesh: a zero-inflated regression analysis

    Directory of Open Access Journals (Sweden)

    Yunus Mohammad

    2010-03-01

    Full Text Available Abstract Background Alteration of natural or historical aquatic flows can have unintended consequences for regions where waterborne diseases are endemic and where the epidemiologic implications of such change are poorly understood. The implementation of flood protection measures for a portion of an intensely monitored population in Matlab, Bangladesh, allows us to examine whether cholera outcomes respond positively or negatively to measures designed to control river flooding. Methods Using a zero inflated negative binomial model, we examine how selected covariates can simultaneously account for household clusters reporting no cholera from those with positive counts as well as distinguishing residential areas with low counts from areas with high cholera counts. Our goal is to examine how residence within or outside a flood protected area interacts with the probability of cholera presence and the effect of flood protection on the magnitude of cholera prevalence. Results In Matlab, living in a household that is protected from annual monsoon flooding appears to have no significant effect on whether the household experiences cholera, net of other covariates. However, counter-intuitively, among households where cholera is reported, living within the flood protected region significantly increases the number of cholera cases. Conclusions The construction of dams or other water impoundment strategies for economic or social motives can have profound and unanticipated consequences for waterborne disease. Our results indicate that the construction of a flood control structure in rural Bangladesh is correlated with an increase in cholera cases for residents protected from annual monsoon flooding. Such a finding requires attention from both the health community and from governments and non-governmental organizations involved in ongoing water management schemes.

  1. The Dynamics of Genetic Interactions between Vibrio metoecus and Vibrio cholerae, Two Close Relatives Co-Occurring in the Environment.

    Science.gov (United States)

    Orata, Fabini D; Kirchberger, Paul C; Méheust, Raphaël; Barlow, E Jed; Tarr, Cheryl L; Boucher, Yan

    2015-10-09

    Vibrio metoecus is the closest relative of Vibrio cholerae, the causative agent of the potent diarrheal disease cholera. Although the pathogenic potential of this new species is yet to be studied in depth, it has been co-isolated with V. cholerae in coastal waters and found in clinical specimens in the United States. We used these two organisms to investigate the genetic interaction between closely related species in their natural environment. The genomes of 20 V. cholerae and 4 V. metoecus strains isolated from a brackish coastal pond on the US east coast, as well as 4 clinical V. metoecus strains were sequenced and compared with reference strains. Whole genome comparison shows 86-87% average nucleotide identity (ANI) in their core genes between the two species. On the other hand, the chromosomal integron, which occupies approximately 3% of their genomes, shows higher conservation in ANI between species than any other region of their genomes. The ANI of 93-94% observed in this region is not significantly greater within than between species, meaning that it does not follow species boundaries. Vibrio metoecus does not encode toxigenic V. cholerae major virulence factors, the cholera toxin and toxin-coregulated pilus. However, some of the pathogenicity islands found in pandemic V. cholerae were either present in the common ancestor it shares with V. metoecus, or acquired by clinical and environmental V. metoecus in partial fragments. The virulence factors of V. cholerae are therefore both more ancient and more widespread than previously believed. There is high interspecies recombination in the core genome, which has been detected in 24% of the single-copy core genes, including genes involved in pathogenicity. Vibrio metoecus was six times more often the recipient of DNA from V. cholerae as it was the donor, indicating a strong bias in the direction of gene transfer in the environment.

  2. Clinical, epidemiological, and spatial characteristics of Vibrio parahaemolyticus diarrhea and cholera in the urban slums of Kolkata, India

    Directory of Open Access Journals (Sweden)

    Kanungo Suman

    2012-09-01

    Full Text Available Abstract Background There is not much information on the differences in clinical, epidemiological and spatial characteristics of diarrhea due to V. cholerae and V. parahaemolyticus from non-coastal areas. We investigated the differences in clinical, epidemiological and spatial characteristics of the two Vibrio species in the urban slums of Kolkata, India. Methods The data of a cluster randomized cholera vaccine trial were used. We restricted the analysis to clusters assigned to placebo. Survival analysis of the time to the first episode was used to analyze risk factors for V. parahaemolyticus diarrhea or cholera. A spatial scan test was used to identify high risk areas for cholera and for V. parahaemolyticus diarrhea. Results In total, 54,519 people from the placebo clusters were assembled. The incidence of cholera (1.30/1000/year was significantly higher than that of V. parahaemolyticus diarrhea (0.63/1000/year. Cholera incidence was inversely related to age, whereas the risk of V. parahaemolyticus diarrhea was age-independent. The seasonality of diarrhea due to the two Vibrio species was similar. Cholera was distinguished by a higher frequency of severe dehydration, and V. parahaemolyticus diarrhea was by abdominal pain. Hindus and those who live in household not using boiled or treated water were more likely to have V. parahaemolyticus diarrhea. Young age, low socioeconomic status, and living closer to a project healthcare facility were associated with an increased risk for cholera. The high risk area for cholera differed from the high risk area for V. parahaemolyticus diarrhea. Conclusion We report coexistence of the two vibrios in the slums of Kolkata. The two etiologies of diarrhea had a similar seasonality but had distinguishing clinical features. The risk factors and the high risk areas for the two diseases differ from one another suggesting different modes of transmission of these two pathogens.

  3. O139霍乱弧菌肠毒素核苷酸序列分析%Nucleotide sequence analysis of cholera toxin in Vibrio cholerae O139

    Institute of Scientific and Technical Information of China (English)

    王军; 王玺华; 白文林; 施红; 金磊

    2000-01-01

    目的 探讨O139霍乱弧菌肠毒素(CTX)核苷酸与O1群霍乱CTX毒素核苷酸序列异同.方法 用聚合酶链反应、DNA序列分析测定2株O139群、2株O1群古典型、2株O1群E1 Tor型霍乱弧菌CTX A2-B亚单位核苷酸.结果 2株O139群霍乱弧菌均含有CTX A2-B亚单位基因,O139群与O1群CTX A2-B核苷酸同源性为97.1%~98.9%.结论 O139群与O1群霍乱弧菌CTX A2-B核苷酸基本同源.进一步证实两者CTX核苷酸序列一致.%Objective To investigate the difference of nucleotide sequence between cholera toxin (CTX)of O139 and O1 Vibrio cholerae.Methods Polymerase chain reaction and DNA sequence analysis were used to study 2 strains of O139.2 strains of classical biotype and 2 strains of EI Tor hiotype.Results Both the 2 strains of cholerae O139 contained the fragment of CTX A2-B gene,and the homology befween O1 and O139 serogroups was 98.9%~97.1%.Conclusion The nucleotide sequence of CTX A2-B in Vibrio cholerae O139 was almost consistent with that in O1,which reconfirmed the consistence of the nucleotide sequence of CTX in the 2 serogroups of Vibrio cholorae.

  4. Effects of Small Molecule Calcium-Activated Chloride Channel Inhibitors on Structure and Function of Accessory Cholera Enterotoxin (Ace of Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Tanaya Chatterjee

    Full Text Available Cholera pathogenesis occurs due to synergistic pro-secretory effects of several toxins, such as cholera toxin (CTX and Accessory cholera enterotoxin (Ace secreted by Vibrio cholerae strains. Ace activates chloride channels stimulating chloride/bicarbonate transport that augments fluid secretion resulting in diarrhea. These channels have been targeted for drug development. However, lesser attention has been paid to the interaction of chloride channel modulators with bacterial toxins. Here we report the modulation of the structure/function of recombinant Ace by small molecule calcium-activated chloride channel (CaCC inhibitors, namely CaCCinh-A01, digallic acid (DGA and tannic acid. Biophysical studies indicate that the unfolding (induced by urea free energy increases upon binding CaCCinh-A01 and DGA, compared to native Ace, whereas binding of tannic acid destabilizes the protein. Far-UV CD experiments revealed that the α-helical content of Ace-CaCCinh-A01 and Ace-DGA complexes increased relative to Ace. In contrast, binding to tannic acid had the opposite effect, indicating the loss of protein secondary structure. The modulation of Ace structure induced by CaCC inhibitors was also analyzed using docking and molecular dynamics (MD simulation. Functional studies, performed using mouse ileal loops and Ussing chamber experiments, corroborate biophysical data, all pointing to the fact that tannic acid destabilizes Ace, inhibiting its function, whereas DGA stabilizes the toxin with enhanced fluid accumulation in mouse ileal loop. The efficacy of tannic acid in mouse model suggests that the targeted modulation of Ace structure may be of therapeutic benefit for gastrointestinal disorders.

  5. Effects of Small Molecule Calcium-Activated Chloride Channel Inhibitors on Structure and Function of Accessory Cholera Enterotoxin (Ace) of Vibrio cholerae

    Science.gov (United States)

    Chatterjee, Tanaya; Sheikh, Irshad Ali; Chakravarty, Devlina; Chakrabarti, Pinak; Sarkar, Paramita; Saha, Tultul; Chakrabarti, Manoj K.; Hoque, Kazi Mirajul

    2015-01-01

    Cholera pathogenesis occurs due to synergistic pro-secretory effects of several toxins, such as cholera toxin (CTX) and Accessory cholera enterotoxin (Ace) secreted by Vibrio cholerae strains. Ace activates chloride channels stimulating chloride/bicarbonate transport that augments fluid secretion resulting in diarrhea. These channels have been targeted for drug development. However, lesser attention has been paid to the interaction of chloride channel modulators with bacterial toxins. Here we report the modulation of the structure/function of recombinant Ace by small molecule calcium-activated chloride channel (CaCC) inhibitors, namely CaCCinh-A01, digallic acid (DGA) and tannic acid. Biophysical studies indicate that the unfolding (induced by urea) free energy increases upon binding CaCCinh-A01 and DGA, compared to native Ace, whereas binding of tannic acid destabilizes the protein. Far-UV CD experiments revealed that the α-helical content of Ace-CaCCinh-A01 and Ace-DGA complexes increased relative to Ace. In contrast, binding to tannic acid had the opposite effect, indicating the loss of protein secondary structure. The modulation of Ace structure induced by CaCC inhibitors was also analyzed using docking and molecular dynamics (MD) simulation. Functional studies, performed using mouse ileal loops and Ussing chamber experiments, corroborate biophysical data, all pointing to the fact that tannic acid destabilizes Ace, inhibiting its function, whereas DGA stabilizes the toxin with enhanced fluid accumulation in mouse ileal loop. The efficacy of tannic acid in mouse model suggests that the targeted modulation of Ace structure may be of therapeutic benefit for gastrointestinal disorders. PMID:26540279

  6. Pandemic spread of cholera: genetic diversity and relationships within the seventh pandemic clone of Vibrio cholerae determined by amplified fragment length polymorphism.

    Science.gov (United States)

    Lan, Ruiting; Reeves, Peter R

    2002-01-01

    The seventh cholera pandemic started in 1961 and continues today. A collection of 45 seventh pandemic isolates of V. cholerae sampled over a 33-year period were analyzed by amplified fragment length polymorphism (AFLP) fingerprinting. All but four pairs and one set of three isolates were distinguished. AFLP revealed far more variation than ribotyping, which was until now the most useful method of revealing variation within the pandemic clone. Unfortunately, the ribotype variation observed is mainly due to recombination between the multiple copies of the rrn genes (R. Lan and P. R. Reeves, Microbiology 144:1213-1221, 1998), which makes changes susceptible to repeat occurrences and reversion. This AFLP study shows that particularly for the common ribotypes G and H, such events have indeed occurred. AFLP grouped most of the 45 isolates into two clusters. Cluster I consists mainly of strains from the 1960s and 1970s, while cluster II contains mainly strains from the 1980s and 1990s, revealing a temporal pattern of change in the clone. This is best seen in the relationships of the strains from Africa, which correlate with the epidemiology of epidemics on that continent. The data confirm independent introductions to Africa during the 1970s outbreak and reveal several other African introductions. In the 1991 cholera upsurge, isolates from the Southern and Eastern African epidemic focus are markedly different from those from the West African epidemic focus. An isolate from 1987 in Algeria was identical to the West epidemic isolates, suggesting that the strain was present in Africa at least 3 years before causing large outbreaks. These observations have major implications for our understanding of cholera epidemiology. PMID:11773113

  7. Emergence of Tetracycline Resistant Vibrio cholerae O1 Biotype El Tor Serotype Ogawa with Classical ctxB Gene from a Cholera Outbreak in Odisha, Eastern India.

    Science.gov (United States)

    Jain, M; Kumar, P; Goel, A K

    2016-01-01

    In September 2010, a cholera outbreak was reported from Odisha, Eastern India. V. cholerae isolated from the clinical samples were biochemically and serologically confirmed as serogroup O1, biotype El Tor, and serotype Ogawa. Multiplex PCR screening revealed the presence of various genes, namely, ompW, ctxB, zot, rfbO1, tcp, ace, hlyA, ompU, rtx, and toxR, in all of the isolates. The isolates were resistant to co-trimoxazole, nalidixic acid, polymyxin B, spectinomycin, streptomycin, sulfamethoxazole, tetracycline, trimethoprim, and vibriostatic agent 2,4-diamino-6,7-diisopropylpteridine (O/129). Minimum inhibitory concentration of tetracycline decreased in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), suggesting the involvement of efflux pumps. PCR analysis confirmed the presence of class I integrons as well as SXT elements harbouring antibiotic resistance genes in all isolates. Sequencing revealed the presence of ctxB gene of classical biotype in all the isolates. The isolates harboured an RS1-CTX prophage array with El Tor type rstR and classical ctxB on the large chromosome. The study indicated that the V. cholerae El Tor variants are evolving in the area with better antibiotic resistance and virulence potential.

  8. Emergence of Tetracycline Resistant Vibrio cholerae O1 Biotype El Tor Serotype Ogawa with Classical ctxB Gene from a Cholera Outbreak in Odisha, Eastern India.

    Science.gov (United States)

    Jain, M; Kumar, P; Goel, A K

    2016-01-01

    In September 2010, a cholera outbreak was reported from Odisha, Eastern India. V. cholerae isolated from the clinical samples were biochemically and serologically confirmed as serogroup O1, biotype El Tor, and serotype Ogawa. Multiplex PCR screening revealed the presence of various genes, namely, ompW, ctxB, zot, rfbO1, tcp, ace, hlyA, ompU, rtx, and toxR, in all of the isolates. The isolates were resistant to co-trimoxazole, nalidixic acid, polymyxin B, spectinomycin, streptomycin, sulfamethoxazole, tetracycline, trimethoprim, and vibriostatic agent 2,4-diamino-6,7-diisopropylpteridine (O/129). Minimum inhibitory concentration of tetracycline decreased in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), suggesting the involvement of efflux pumps. PCR analysis confirmed the presence of class I integrons as well as SXT elements harbouring antibiotic resistance genes in all isolates. Sequencing revealed the presence of ctxB gene of classical biotype in all the isolates. The isolates harboured an RS1-CTX prophage array with El Tor type rstR and classical ctxB on the large chromosome. The study indicated that the V. cholerae El Tor variants are evolving in the area with better antibiotic resistance and virulence potential. PMID:26881083

  9. High-resolution spatial analysis of cholera patients reported in Artibonite department, Haiti in 2010–2011

    Directory of Open Access Journals (Sweden)

    Maya Allan

    2016-03-01

    Conclusion/significance: These findings demonstrate the value of high-resolution mapping for pinpointing locations most affected by cholera, and in the future could help prioritize the places in need of interventions such as improvement of sanitation and vaccination. The findings also describe spatio-temporal transmission patterns of the epidemic in a cholera-naïve country such as Haiti. By identifying transmission hubs, it is possible to target prevention strategies that, over time, could reduce transmission of the disease and eventually eliminate cholera in Haiti.

  10. 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

    .19; 95% CI, 0.04-0.91, adjusted for age). The 3 breastfed children who developed cholera received milk containing lower concentrations of anticholera toxin IgA/total IgA (median, 2.0 units/mL) than 14 children who had serologic signs of colonization but did not develop the disease (median, 17.4 units...

  11. Phenotypic Analysis Reveals that the 2010 Haiti Cholera Epidemic Is Linked to a Hypervirulent Strain.

    Science.gov (United States)

    Satchell, Karla J F; Jones, Christopher J; Wong, Jennifer; Queen, Jessica; Agarwal, Shivani; Yildiz, Fitnat H

    2016-09-01

    Vibrio cholerae O1 El Tor strains have been responsible for pandemic cholera since 1961. These strains have evolved over time, spreading globally in three separate waves. Wave 3 is caused by altered El Tor (AET) variant strains, which include the strain with the signature ctxB7 allele that was introduced in 2010 into Haiti, where it caused a devastating epidemic. In this study, we used phenotypic analysis to compare an early isolate from the Haiti epidemic to wave 1 El Tor isolates commonly used for research. It is demonstrated that the Haiti isolate has increased production of cholera toxin (CT) and hemolysin, increased motility, and a reduced ability to form biofilms. This strain also outcompetes common wave 1 El Tor isolates for colonization of infant mice, indicating that it has increased virulence. Monitoring of CT production and motility in additional wave 3 isolates revealed that this phenotypic variation likely evolved over time rather than in a single genetic event. Analysis of available whole-genome sequences and phylogenetic analyses suggested that increased virulence arose from positive selection for mutations found in known and putative regulatory genes, including hns and vieA, diguanylate cyclase genes, and genes belonging to the lysR and gntR regulatory families. Overall, the studies presented here revealed that V. cholerae virulence potential can evolve and that the currently prevalent wave 3 AET strains are both phenotypically distinct from and more virulent than many El Tor isolates. PMID:27297393

  12. A checkpoint control orchestrates the replication of the two chromosomes of Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Marbouty, Martial; Martins, Francisco de Lemos;

    2016-01-01

    important differences between plasmids and chromosomes is that the latter replicate during a defined period of the cell cycle, ensuring a single round of replication per cell. Vibrio cholerae carries two circular chromosomes, Chr1 and Chr2, which are replicated in a well-orchestrated manner with the cell...

  13. The role of climate and socioeconomic factors on the spatiotemporal variability of cholera in Nigeria

    Science.gov (United States)

    Abdussalam, Auwal; Thornes, John; Leckebusch, Gregor

    2015-04-01

    Nigeria has a number of climate-sensitive infectious diseases; one of the most important of these diseases that remains a threat to public health is cholera. This study investigates the influences of both meteorological and socioeconomic factors on the spatiotemporal variability of cholera in Nigeria. A stepwise multiple regression models are used to estimate the influence of the year-to-year variations of cholera cases and deaths for individual states in the country and as well for three groups of states that are classified based on annual rainfall amount. Specifically, seasonal mean maximum and minimum temperatures and annual rainfall totals were analysed with annual aggregate count of cholera cases and deaths, taking into account of the socioeconomic factors that are potentially enhancing vulnerability such as: absolute poverty, adult literacy, access to pipe borne water and population density. Result reveals that the most important explanatory meteorological and socioeconomic variables in explaining the spatiotemporal variability of the disease are rainfall totals, seasonal mean maximum temperature, absolute poverty, and accessibility to pipe borne water. The influences of socioeconomic factors appeared to be more pronounced in the northern part of the country, and vice-versa in the case of meteorological factors. Also, cross validated models output suggests a strong possibility of disease prediction, which will help authorities to put effective control measures in place which depend on prevention, and or efficient response.

  14. Urban Cholera and Water Sustainability Challenges under Climatic and Anthropogenic Change

    Science.gov (United States)

    Akanda, A. S.; Jutla, A.; Huq, A.; Faruque, A. G.; Colwell, R. R.

    2013-12-01

    The last three decades of surveillance data shows a drastic increase of cholera prevalence in the largest cholera-endemic city of the world - Dhaka, Bangladesh. Emerging megacities in the developing world, especially those located in coastal regions of the tropics remain vulnerable to similar. However, there has not been any systematic study on linking the long-term disease trends with changes in related climatic, environmental, or societal variables. Here, we analyze the 30-year dynamics of urban cholera prevalence in Dhaka with changes in climatic or societal factors: regional hydrology, flooding, water usage, changes in distribution systems, population growth and density in urban settlements, as well as shifting climate patterns. An interesting change is observed in the seasonal trends of cholera incidence; while an endemic upward trend is seen in the dry season, the post-monsoon trend seem to be more epidemic in nature. Evidence points to growing urbanization and rising population in unplanned settlements that have negligible to poor water and sanitation systems compounded by increasing frequency of record flood events. Growing water scarcity in the dry season and lack of sustainable water and sanitation infrastructure for urban settlements have increased endemicity of spring outbreaks, while record flood events and prolonged post-monsoon inundation have contributed to increased epidemic outbreaks in fall. We analyze our findings with the World Health Organization recommended guidelines and investigate water sustainability challenges in the context of climatic and anthropogenic changes in the region.

  15. Evaluation of the protective efficacy of Vibrio cholerae ghost (VCG) candidate vaccines in rabbits.

    Science.gov (United States)

    Eko, Francis O; Schukovskaya, Tatiana; Lotzmanova, E Y; Firstova, V V; Emalyanova, N V; Klueva, S N; Kravtzov, A L; Livanova, L F; Kutyrev, Vladimir V; Igietseme, Joseph U; Lubitz, Werner

    2003-09-01

    An effective Vibrio cholerae vaccine is needed to reduce the morbidity and mortality caused by this pathogen. Despite the availability of current oral vaccines with measurable efficacy, there is need for more effective vaccines with broad-spectrum efficacy in target populations. Recent studies have shown that bacterial ghosts, produced by the expression of cloned lysis gene E, possess adjuvant properties and are immunogenic. In this study, ghosts were prepared from V. cholerae O1 or O139 and evaluated as vaccines in the reversible intestinal tie adult rabbit diarrhea (RITARD) model. Rabbits were orally immunized with different doses of V. cholerae ghost (VCG) formulations. The vaccine formulations elicited high levels of serum vibriocidal titers against indicator strains. The magnitude of the response was measured as the geometric mean titer (GMT) increase for all rabbits in relation to prevaccination titers. The induction of cross protection was evidenced by the ability of serum from VCG-immunized rabbits to mediate complement-dependent killing of both the homologous and the heterologous strains. Immunized rabbits were protected against intraduodenal challenge 30 days after primary immunization. Protective immunity against challenge appeared to be dose dependent and was associated with marked inhibition of colonization. These results indicate that VCGs represent a novel approach to cholera vaccine development and constitute an effective vaccine delivery vehicle. PMID:12922096

  16. Vibrio cholerae hemagglutinin(HA)/protease: An extracellular metalloprotease with multiple pathogenic activities.

    Science.gov (United States)

    Benitez, Jorge A; Silva, Anisia J

    2016-06-01

    Vibrio cholerae of serogroup O1 and O139, the etiological agent of the diarrheal disease cholera, expresses the extracellular Zn-dependent metalloprotease hemagglutinin (HA)/protease also reported as vibriolysin. This enzyme is also produced by non-O1/O139 (non-cholera) strains that cause mild, sporadic illness (i.e. gastroenteritis, wound or ear infections). Orthologs of HA/protease are present in other members of the Vibrionaceae family pathogenic to humans and fish. HA/protease belongs to the M4 neutral peptidase family and displays significant amino acid sequence homology to Pseudomonas aeruginosa elastase (LasB) and Bacillus thermoproteolyticus thermolysin. It exhibits a broad range of potentially pathogenic activities in cell culture and animal models. These activities range from the covalent modification of other toxins, the degradation of the protective mucus barrier and disruption of intestinal tight junctions. Here we review (i) the structure and regulation of HA/protease expression, (ii) its interaction with other toxins and the intestinal mucosa and (iii) discuss the possible role(s) of HA/protease in the pathogenesis of cholera. PMID:26952544

  17. Bile Salts Modulate the Mucin-Activated Type VI Secretion System of Pandemic Vibrio cholerae.

    Science.gov (United States)

    Bachmann, Verena; Kostiuk, Benjamin; Unterweger, Daniel; Diaz-Satizabal, Laura; Ogg, Stephen; Pukatzki, Stefan

    2015-01-01

    The causative agent of cholera, Vibrio cholerae, regulates its diverse virulence factors to thrive in the human small intestine and environmental reservoirs. Among this pathogen's arsenal of virulence factors is the tightly regulated type VI secretion system (T6SS). This system acts as an inverted bacteriophage to inject toxins into competing bacteria and eukaryotic phagocytes. V. cholerae strains responsible for the current 7th pandemic activate their T6SS within the host. We established that T6SS-mediated competition occurs upon T6SS activation in the infant mouse, and that this system is functional under anaerobic conditions. When investigating the intestinal host factors mucins (a glycoprotein component of mucus) and bile for potential regulatory roles in controlling the T6SS, we discovered that once mucins activate the T6SS, bile acids can further modulate T6SS activity. Microbiota modify bile acids to inhibit T6SS-mediated killing of commensal bacteria. This interplay is a novel interaction between commensal bacteria, host factors, and the V. cholerae T6SS, showing an active host role in infection.

  18. Variations in SXT elements in epidemic Vibrio cholerae O1 El Tor strains in China.

    Science.gov (United States)

    Wang, Ruibai; Yu, Dong; Yue, Junjie; Kan, Biao

    2016-03-09

    Vibrio cholerae O1 El Tor biotype strains are responsible for three multiyear epidemics of cholera in China during the seventh ongoing pandemic. The presence of the integrative conjugative element SXT is strongly correlated with resistance to nalidixic acid, tetracycline, and trimethoprim-sulfamethoxazole in these strains. Here, we sequenced the conserved genes of the SXT element, including eex, setR, and int, from 59 V. cholerae O1 El Tor strains and extracted and assembled the intact SXT sequences from the 11 genome sequenced strains. These elements had characteristics distinct from those of previously reported integrative conjugative elements (ICEs). They could be clearly divided into two types based on the clustering of conserved genes and gene structures of the elements, showing their possibly independent derivation and evolution. These two types were present before and after 2005, respectively, demonstrating the type substitution that occurred in 2005. Four to six antibiotic-resistant genes were found on the SXT elements, including genes resistant to tetracycline, trimethoprim-sulfamethoxazole, and multiple drugs. In summary, our findings demonstrated the roles of the SXT element in the emergence of multidrug resistance in epidemic O1 El Tor V. cholerae strains in China.

  19. 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...

  20. Antimicrobial Drug Resistance of Vibrio cholerae, Democratic Republic of the Congo.

    Science.gov (United States)

    Miwanda, Berthe; Moore, Sandra; Muyembe, Jean-Jacques; Nguefack-Tsague, Georges; Kabangwa, Ickel Kakongo; Ndjakani, Daniel Yassa; Mutreja, Ankur; Thomson, Nicholas; Thefenne, Helene; Garnotel, Eric; Tshapenda, Gaston; Kakongo, Denis Kandolo; Kalambayi, Guy; Piarroux, Renaud

    2015-05-01

    We analyzed 1,093 Vibrio cholerae isolates from the Democratic Republic of the Congo during 1997-2012 and found increasing antimicrobial drug resistance over time. Our study also demonstrated that the 2011-2012 epidemic was caused by an El Tor variant clonal complex with a single antimicrobial drug susceptibility profile.

  1. Comparative genomics of 274 Vibrio cholerae genomes reveals mobile functions structuring three niche dimensions

    NARCIS (Netherlands)

    Dutilh, B.E.; Thompson, C.C.; Vicente, A.C.; Marin, M.A.; Lee, C.; Silva, G.G.; Schmieder, R.; Andrade, B.G.; Chimetto, L.; Cuevas, D.; Garza, D.R.; Okeke, I.N.; Aboderin, A.O.; Spangler, J.; Ross, T.; Dinsdale, E.A.; Thompson, F.L.; Harkins, T.T.; Edwards, R.A.

    2014-01-01

    BACKGROUND: Vibrio cholerae is a globally dispersed pathogen that has evolved with humans for centuries, but also includes non-pathogenic environmental strains. Here, we identify the genomic variability underlying this remarkable persistence across the three major niche dimensions space, time, and h

  2. Phenotypic, Genotypic, and Antibiotic Sensitivity Patterns of Strains Isolated from the Cholera Epidemic in Zimbabwe

    NARCIS (Netherlands)

    Islam, Mohammad S.; Mahmud, Zahid H.; Ansaruzzaman, Mohammad; Faruque, Shah M.; Talukder, Kaisar A.; Qadri, Firdausi; Alam, Munirul; Islam, Shafiqul; Bardhan, Pradip K.; Mazumder, Ramendra N.; Khan, Azharul I.; Ahmed, Sirajuddin; Iqbal, Anwarul; Chitsatso, Owen; Mudzori, James; Patel, Sheetal; Midzi, Stanley M.; Charimari, Lincoln; Endtz, Hubert P.; Cravioto, Alejandro

    2011-01-01

    This paper details the phenotypic, genotypic, and antibiotic sensitivity patterns of 88 Vibrio cholerae strains from Zimbabwe. Of the 88 strains, 83 were classified as "altered El Tor" and 5 as "hybrid El Tor" strains. All of the strains were susceptible to tetracycline, doxycycline, ciprofloxacin,

  3. Fuse or die: how to survive the loss of Dam in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Kennedy, Sean P; Soler-Bistue, Alfonso J.;

    2014-01-01

    Dam methylates GATC sequences in γ-proteobacteria genomes, regulating several cellular functions including replication. In Vibrio cholerae, which has two chromosomes, Dam is essential for viability, owing to its role in chr2 replication initiation. In this study, we isolated spontaneous mutants...

  4. Temperature affects c-di-GMP signalling and biofilm formation in Vibrio cholerae.

    Science.gov (United States)

    Townsley, Loni; Yildiz, Fitnat H

    2015-11-01

    Biofilm formation is crucial to the environmental survival and transmission of Vibrio cholerae, the facultative human pathogen responsible for the disease cholera. During its infectious cycle, V. cholerae experiences fluctuations in temperature within the aquatic environment and during the transition between human host and aquatic reservoirs. In this study, we report that biofilm formation is induced at low temperatures through increased levels of the signalling molecule, cyclic diguanylate (c-di-GMP). Strains harbouring in frame deletions of all V. cholerae genes that are predicted to encode diguanylate cyclases (DGCs) or phosphodiesterases (PDEs) were screened for their involvement in low-temperature-induced biofilm formation and Vibrio polysaccharide gene expression. Of the 52 mutants tested, deletions of six DGCs and three PDEs were found to affect these phenotypes at low temperatures. Unlike wild type, a strain lacking all six DGCs did not exhibit a low-temperature-dependent increase in c-di-GMP, indicating that these DGCs are required for temperature modulation of c-di-GMP levels. We also show that temperature modulates c-di-GMP levels in a similar fashion in the Gram-negative pathogen Pseudomonas aeruginosa but not in the Gram-positive pathogen Listeria monocytogenes. This study uncovers the role of temperature in environmental regulation of biofilm formation and c-di-GMP signalling.

  5. Chimeric adaptor proteins translocate diverse type VI secretion system effectors in Vibrio cholerae.

    Science.gov (United States)

    Unterweger, Daniel; Kostiuk, Benjamin; Ötjengerdes, Rina; Wilton, Ashley; Diaz-Satizabal, Laura; Pukatzki, Stefan

    2015-08-13

    Vibrio cholerae is a diverse species of Gram-negative bacteria, commonly found in the aquatic environment and the causative agent of the potentially deadly disease cholera. These bacteria employ a type VI secretion system (T6SS) when they encounter prokaryotic and eukaryotic competitors. This contractile puncturing device translocates a set of effector proteins into neighboring cells. Translocated effectors are toxic unless the targeted cell produces immunity proteins that bind and deactivate incoming effectors. Comparison of multiple V. cholerae strains indicates that effectors are encoded in T6SS effector modules on mobile genetic elements. We identified a diverse group of chimeric T6SS adaptor proteins required for the translocation of diverse effectors encoded in modules. An example for a T6SS effector that requires T6SS adaptor protein 1 (Tap-1) is TseL found in pandemic V. cholerae O1 serogroup strains and other clinical isolates. We propose a model in which Tap-1 is required for loading TseL onto the secretion apparatus. After T6SS-mediated TseL export is completed, Tap-1 is retained in the bacterial cell to load other T6SS machines.

  6. A checkpoint control orchestrates the replication of the two chromosomes of Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Marbouty, Martial; Martins, Francisco de Lemos;

    2016-01-01

    of the important differences between plasmids and chromosomes is that the latter replicate during a defined period of the cell cycle, ensuring a single round of replication per cell. Vibrio cholerae carries two circular chromosomes, Chr1 and Chr2, which are replicated in a well-orchestrated manner with the cell...

  7. Gene dosage compensation calibrates four regulatory RNAs to control Vibrio cholerae quorum sensing

    DEFF Research Database (Denmark)

    Svenningsen, Sine L; Tu, Kimberly C; Bassler, Bonnie L

    2009-01-01

    Quorum sensing is a mechanism of cell-to-cell communication that allows bacteria to coordinately regulate gene expression in response to changes in cell-population density. At the core of the Vibrio cholerae quorum-sensing signal transduction pathway reside four homologous small RNAs (sRNAs), named...

  8. Bile Salts Modulate the Mucin-Activated Type VI Secretion System of Pandemic Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Verena Bachmann

    Full Text Available The causative agent of cholera, Vibrio cholerae, regulates its diverse virulence factors to thrive in the human small intestine and environmental reservoirs. Among this pathogen's arsenal of virulence factors is the tightly regulated type VI secretion system (T6SS. This system acts as an inverted bacteriophage to inject toxins into competing bacteria and eukaryotic phagocytes. V. cholerae strains responsible for the current 7th pandemic activate their T6SS within the host. We established that T6SS-mediated competition occurs upon T6SS activation in the infant mouse, and that this system is functional under anaerobic conditions. When investigating the intestinal host factors mucins (a glycoprotein component of mucus and bile for potential regulatory roles in controlling the T6SS, we discovered that once mucins activate the T6SS, bile acids can further modulate T6SS activity. Microbiota modify bile acids to inhibit T6SS-mediated killing of commensal bacteria. This interplay is a novel interaction between commensal bacteria, host factors, and the V. cholerae T6SS, showing an active host role in infection.

  9. Crystallization of the HigBA2 toxin-antitoxin complex from Vibrio cholerae

    DEFF Research Database (Denmark)

    Hadǽi, San; Garcia-Pino, Abel; Martinez-Rodriguez, Sergio;

    2013-01-01

    The genome of Vibrio cholerae encodes two higBA toxin-antitoxin (TA) modules that are activated by amino-acid starvation. Here, the TA complex of the second module, higBA2, as well as the C-terminal domain of the corresponding HigA2 antitoxin, have been purified and crystallized. The HigBA2 complex...

  10. 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...

  11. Vibrio cholerae phosphatases required for the utilization of nucleotides and extracellular DNA as phosphate sources.

    Science.gov (United States)

    McDonough, EmilyKate; Kamp, Heather; Camilli, Andrew

    2016-02-01

    Phosphate is essential for life, being used in many core processes such as signal transduction and synthesis of nucleic acids. The waterborne agent of cholera, Vibrio cholerae, encounters phosphate limitation in both the aquatic environment and human intestinal tract. This bacterium can utilize extracellular DNA (eDNA) as a phosphate source, a phenotype dependent on secreted endo- and exonucleases. However, no transporter of nucleotides has been identified in V. cholerae, suggesting that in order for the organism to utilize the DNA as a phosphate source, it must first separate the phosphate and nucleoside groups before transporting phosphate into the cell. In this study, we investigated the factors required for assimilation of phosphate from eDNA. We identified PhoX, and the previously unknown proteins UshA and CpdB as the major phosphatases that allow phosphate acquisition from eDNA and nucleotides. We demonstrated separable but partially overlapping roles for the three phosphatases and showed that the activity of PhoX and CpdB is induced by phosphate limitation. Thus, this study provides mechanistic insight into how V. cholerae can acquire phosphate from extracellular DNA, which is likely to be an important phosphate source in the environment and during infection.

  12. A Two-Step Synthesis of Virstatin, a Virulence Inhibitor of "Vibrio cholerae"

    Science.gov (United States)

    McDonald, Chriss E.

    2009-01-01

    Virstatin, an "N"-butanoic acid substituted naphthalimide, inhibits the ability of "Vibrio cholerae" to cause disease. A three-week experiment involving synthesis, purification, and spectral characterization of this compound is described. This experiment is appropriate for organic chemistry. It has been performed with three lab sections of about…

  13. Cerebral absces med Vibrio cholerae non-01 efter badning i dansk havvand

    DEFF Research Database (Denmark)

    Torp-Pedersen, Trine; Nielsen, Xiaohui Chen; Olsen, Katharina E P;

    2012-01-01

    We present the first case of intracerebral abscess after blood-borne infection with non-toxigenic Vibrio cholerae (non-01). The patient was a 66 year-old woman who was infected after swimming in Danish seawater during an unusually hot summer. She had predisposing haemochromatosis and a skin lesion...

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

    Directory of Open Access Journals (Sweden)

    Verena Olivier

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

  15. Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, Bodil; Pallesen, Lars; Jensen, Lars Bogø;

    1997-01-01

    . Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...

  16. Uptake during an oral cholera vaccine pilot demonstration program, Odisha, India.

    Science.gov (United States)

    Kar, Shantanu K; Pach, Alfred; Sah, Binod; Kerketta, Anna S; Patnaik, Bikash; Mogasale, VijayaLaxmi; Kim, Yang Hee; Rath, Shyam Bandhu; Shin, Sunheang; Khuntia, Hemant K; Bhattachan, Anuj; Puri, Mahesh K; Wierzba, Thomas F; Kaljee, Linda M

    2014-01-01

    Approximately 30% of reported global cholera cases occur in India. In 2011, a household survey was conducted 4 months after an oral cholera vaccine pilot demonstration project in Odisha India to assess factors associated with vaccine up-take and exposure to a communication and social mobilization campaign. Nine villages were purposefully selected based on socio-demographics and demonstration participation rates. Households were stratified by level of participation and randomly selected. Bivariate and ordered logistic regression analyses were conducted. 517/600 (86%) selected households were surveyed. At the household level, participant compared to non-participant households were more likely to use the local primary health centers for general healthcare (P communication, at the household level verbal communication was reported to be more useful than written communication. However written communication was perceived to be more useful by respondents in low-participating villages compared to average-participating villages (p = 0.007) These data on participation in an oral cholera vaccine demonstration program are important in light of the World Health Organization's (WHO) recommendations for pre-emptive use of cholera vaccine among vulnerable populations in endemic settings. Continued research is needed to further delineate barriers to vaccine up-take within and across targeted communities in low- and middle-income countries. PMID:25483631

  17. The Role of the CAI-1 Fatty Acid Tail in the Vibrio cholerae Quorum Sensing Response

    Science.gov (United States)

    Perez, Lark J.; Ng, Wai-Leung; Marano, Paul; Brook, Karolina; Bassler, Bonnie L.; Semmelhack, Martin F.

    2013-01-01

    Quorum sensing is a mechanism of chemical communication among bacteria that enables collective behaviors. In V. cholerae, the etiological agent of the disease cholera, quorum sensing controls group behaviors including virulence factor production and biofilm formation. The major V. cholerae quorum-sensing system consists of the extracellular signal molecule called CAI-1 and its cognate membrane bound receptor called CqsS. Here, the ligand binding activity of CqsS is probed with structural analogs of the natural signal. Enabled by our discovery of a structurally simplified analog of CAI-1, we prepared and analyzed a focused library. The molecules were designed to probe the effects of conformational and structural changes along the length of the fatty acid tail of CAI-1. Our results, combined with pharmacophore modeling, suggest a molecular basis for signal molecule recognition and receptor fidelity with respect to the fatty acid tail portion of CAI-1. These efforts provide novel probes to enhance discovery of anti-virulence agents for the treatment of V. cholerae. PMID:23092313

  18. Carl von Clausewitz (1780-1831) and cholera: the cause of World War II?

    Science.gov (United States)

    Spellberg, Brad

    2005-05-01

    Here it is proposed that, by killing Prussian Major General Carl von Clausewitz before he could complete the work on his military text On War, cholera strongly influenced the nature of World War I (1914-18) and, by direct extension, contributed to the cause of World War II (1939-45). PMID:19813314

  19. Re-emergence of cholera in the Americas: Risks, susceptibility, and ecology

    Directory of Open Access Journals (Sweden)

    Mathieu JP Poirier

    2012-01-01

    Full Text Available Background: The re-emergence of cholera in Haiti has established a new reservoir for the seventh cholera pandemic which threatens to spread to other countries in the Americas. Materials and Methods: Statistics from this new epidemic are compared to the 1991 Peru epidemic, which demonstrated the speed and complexity with which this disease can spread from country to country. Environmental factors implicated in the spread of Vibrio cholerae such as ocean currents and temperatures, as well as biotic factors from zooplankton to waterfowl pose a risk for many countries in the Americas. Results: The movement of people and goods from Hispaniola are mostly destined for North America, but occur to some degree throughout the Americas. These modes of transmission, and the probability of uncontrolled community spread beyond Hispaniola, however, are completely dependent upon risk factors within these countries such as water quality and availability of sanitation. Although North America has excellent coverage of these deterrents to the spread of infectious gastrointestinal diseases, many countries throughout Latin America and the Caribbean lack these basic services and infrastructures. Conclusions : In order to curb the immediate spread of cholera in Hispaniola, treatment availability should be expanded to all parts of the island and phase II epidemic management initiatives must be developed.

  20. Cholera Management and Prevention at Hôpital Albert Schweitzer, Haiti

    OpenAIRE

    Ernst, Silvia; Weinrobe, Carolyn; Bien-Aime, Charbel; Rawson, Ian

    2011-01-01

    In October 2010, Hôpital Albert Schweitzer Haiti treated some of the first patients with cholera in Haiti. Over the following 10 months, a strategic plan was developed and implemented to improve the management of cases at the hospital level and to address the underlying risk factors at the community level.

  1. The Simultaneous Effects of Spatial and Social Networks on Cholera Transmission

    Directory of Open Access Journals (Sweden)

    Sophia Giebultowicz

    2011-01-01

    Full Text Available This study uses social network and spatial analytical methods simultaneously to understand cholera transmission in rural Bangladesh. Both have been used separately to incorporate context into health studies, but using them together is a new and recent approach. Data include a spatially referenced longitudinal demographic database consisting of approximately 200,000 people and a database of all laboratory-confirmed cholera cases from 1983 to 2003. A complete kinship-based network linking households is created, and distance matrices are also constructed to model spatial relationships. A spatial error-social effects model tested for cholera clustering in socially linked households while accounting for spatial factors. Results show that there was social clustering in five out of twenty-one years while accounting for both known and unknown environmental variables. This suggests that environmental cholera transmission is significant and social networks also influence transmission, but not as consistently. Simultaneous spatial and social network analysis may improve understanding of disease transmission.

  2. Geographical structures and the cholera epidemic in modern Japan: Fukushima prefecture in 1882 and 1895

    Directory of Open Access Journals (Sweden)

    Fukui Hiromichi

    2007-06-01

    Full Text Available Abstract Background Disease diffusion patterns can provide clues for understanding geographical change. Fukushima, a rural prefecture in northeast Japan, was chosen for a case study of the late nineteenth century cholera epidemic that occurred in that country. Two volumes of Cholera Ryu-ko Kiji (Cholera Epidemic Report, published by the prefectural government in 1882 and 1895, provide valuable records for analyzing and modelling diffusion. Text descriptions and numerical evidence culled from the reports were incorporated into a temporal-spatial study framework using geographic information system (GIS and geo-statistical techniques. Results Changes in diffusion patterns between 1882 and 1895 reflect improvements in the Fukushima transportation system and growth in social-economic networks. The data reveal different diffusion systems in separate regions in which residents of Fukushima and neighboring prefectures interacted. Our model also shows that an area in the prefecture's northern interior was dominated by a mix of diffusion processes (contagious and hierarchical, that the southern coastal region was affected by a contagious process, and that other infected areas experienced relocation diffusion. Conclusion In addition to enhancing our understanding of epidemics, the spatial-temporal patterns of cholera diffusion offer opportunities for studying regional change in modern Japan. By highlighting the dynamics of regional reorganization, our findings can be used to better understand the formation of an urban hierarchy in late nineteenth century Japan.

  3. Factors Related to Fetal Death in Pregnant Women with Cholera, Haiti, 2011-2014.

    Science.gov (United States)

    Schillberg, Erin; Ariti, Cono; Bryson, Lindsay; Delva-Senat, Rodnie; Price, Debbie; GrandPierre, Reynold; Lenglet, Annick

    2016-01-01

    We assessed risk factors for fetal death during cholera infection and effect of treatment changes on these deaths. Third trimester gestation, younger maternal age, severe dehydration, and vomiting were risk factors. Changes in treatment had limited effects on fetal death, highlighting the need for prevention and evidence-based treatment.

  4. Rapid identification of vibrio-cholerae O1 by coaglutination test using mono-specifis antibody

    Directory of Open Access Journals (Sweden)

    Bazargan SA

    1996-07-01

    Full Text Available In our investigation, rabbit hyper-immune serum to V.cholerae ogawa was absorbed with V.cholerae inaba whole-cells and vice versa. Applying ammonium sulphate precipitation method, mono-specific g globulins were purified and concentrated from the absorbed whole serum. These antibodies were fixed on staphylococcus cowan 1 NCTC-8325 whole-cells, using different chemical fixatives. It was observed that maximum fixation of g globulin to protein-A was achieved by 1-propanol 50% at 3 hours, which revealed through single radial immuno-diffusion techniqe. The rectal swab samples were cultured in an enrichment bile-peptons broth. After 5 hours 37°C while agitations, one drop of each sample was mixed with one drop of vibrio-cholerae bivalent mono-specific coagglutination reagent (VBCR. The results were read after 2 to 3 minutes. Finally though statistical analysis sensitivity and specificity of coagglutination test were calculated to be 95.1% and 99.2% respectively, when compared to positive & negative controls and conventional culture methods. Using VBCR, coagglutination test can be therefore considered as a simple, reliable and rapid method to detect V.cholerae O1 in the stool of patients in endemic area and less equipped laboratories

  5. Quorum regulatory small RNAs repress type VI secretion in Vibrio cholerae.

    Science.gov (United States)

    Shao, Yi; Bassler, Bonnie L

    2014-06-01

    Type VI secretion is critical for Vibrio cholerae to successfully combat phagocytic eukaryotes and to survive in the presence of competing bacterial species. V. cholerae type VI secretion system genes are encoded in one large and two small clusters. In V. cholerae, type VI secretion is controlled by quorum sensing, the cell-cell communication process that enables bacteria to orchestrate group behaviours. The quorum-sensing response regulator LuxO represses type VI secretion genes at low cell density and the quorum-sensing regulator HapR activates type VI secretion genes at high cell density. We demonstrate that the quorum regulatory small RNAs (Qrr sRNAs) that function between LuxO and HapR in the quorum-sensing cascade are required for these regulatory effects. The Qrr sRNAs control type VI secretion via two mechanisms: they repress expression of the large type VI secretion system cluster through base pairing and they repress HapR, the activator of the two small type VI secretion clusters. This regulatory arrangement ensures that the large cluster encoding many components of the secretory machine is expressed prior to the two small clusters that encode the secreted effectors. Qrr sRNA-dependent regulation of the type VI secretion system is conserved in pandemic and non-pandemic V. cholerae strains.

  6. Variations in SXT elements in epidemic Vibrio cholerae O1 El Tor strains in China.

    Science.gov (United States)

    Wang, Ruibai; Yu, Dong; Yue, Junjie; Kan, Biao

    2016-01-01

    Vibrio cholerae O1 El Tor biotype strains are responsible for three multiyear epidemics of cholera in China during the seventh ongoing pandemic. The presence of the integrative conjugative element SXT is strongly correlated with resistance to nalidixic acid, tetracycline, and trimethoprim-sulfamethoxazole in these strains. Here, we sequenced the conserved genes of the SXT element, including eex, setR, and int, from 59 V. cholerae O1 El Tor strains and extracted and assembled the intact SXT sequences from the 11 genome sequenced strains. These elements had characteristics distinct from those of previously reported integrative conjugative elements (ICEs). They could be clearly divided into two types based on the clustering of conserved genes and gene structures of the elements, showing their possibly independent derivation and evolution. These two types were present before and after 2005, respectively, demonstrating the type substitution that occurred in 2005. Four to six antibiotic-resistant genes were found on the SXT elements, including genes resistant to tetracycline, trimethoprim-sulfamethoxazole, and multiple drugs. In summary, our findings demonstrated the roles of the SXT element in the emergence of multidrug resistance in epidemic O1 El Tor V. cholerae strains in China. PMID:26956038

  7. Cholera in Pregnancy: A Systematic Review and Meta-Analysis of Fetal, Neonatal, and Maternal Mortality.

    Directory of Open Access Journals (Sweden)

    Nguyen-Toan Tran

    Full Text Available Maternal infection with cholera may negatively affect pregnancy outcomes. The objective of this research is to systematically review the literature and determine the risk of fetal, neonatal and maternal death associated with cholera during pregnancy.Medline, Global Health Library, and Cochrane Library databases were searched using the key terms cholera and pregnancy for articles published in any language and at any time before August 2013 to quantitatively summarize estimates of fetal, maternal, and neonatal mortality. 95% confidence intervals (CIs were calculated for each selected study. Random-effect non-linear logistic regression was used to calculate pooled rates and 95% CIs by time period. Studies from the recent period (1991-2013 were compared with studies from 1969-1990. Relative risk (RR estimates and 95% CIs were obtained by comparing mortality of selected recent studies with published national normative data from the closest year.The meta-analysis included seven studies that together involved 737 pregnant women with cholera from six countries. The pooled fetal death rate for 4 studies during 1991-2013 was 7.9% (95% CIs 5.3-10.4, significantly lower than that of 3 studies from 1969-1990 (31.0%, 95% CIs 25.2-36.8. There was no difference in fetal death rate by trimester. The pooled neonatal death rate for 1991-2013 studies was 0.8% (95% CIs 0.0-1.6, and 6.4% (95% CIs 0.0-20.8 for 1969-1990. The pooled maternal death rate for 1991-2013 studies was 0.2% (95% CIs 0.0-0.7, and 5.0% (95% CIs 0.0-16.0 for 1969-1990. Compared with published national mortality estimates, the RR for fetal death of 5.8 (95% CIs 2.9-11.3 was calculated for Haiti (2013, 1.8 (95% CIs 0.3-10.4 for Senegal (2007, and 2.6 (95% CIs 0.5-14.9 for Peru (1991; there were no significant differences in the RR for neonatal or maternal death.Results are limited by the inconsistencies found across included studies but suggest that maternal cholera is associated with adverse

  8. Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

    Directory of Open Access Journals (Sweden)

    Qifang Bi

    2016-02-01

    Full Text Available Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98, type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00, and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00 exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a

  9. Cholera epidemic in Guinea-Bissau (2008: the importance of "place".

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    Francisco J Luquero

    Full Text Available BACKGROUND: As resources are limited when responding to cholera outbreaks, knowledge about where to orient interventions is crucial. We describe the cholera epidemic affecting Guinea-Bissau in 2008 focusing on the geographical spread in order to guide prevention and control activities. METHODOLOGY/PRINCIPAL FINDINGS: We conducted two studies: 1 a descriptive analysis of the cholera epidemic in Guinea-Bissau focusing on its geographical spread (country level and within the capital; and 2 a cross-sectional study to measure the prevalence of houses with at least one cholera case in the most affected neighbourhood of the capital (Bairro Bandim to detect clustering of households with cases (cluster analysis. All cholera cases attending the cholera treatment centres in Guinea-Bissau who fulfilled a modified World Health Organization clinical case definition during the epidemic were included in the descriptive study. For the cluster analysis, a sample of houses was selected from a satellite photo (Google Earth™; 140 houses (and the four closest houses were assessed from the 2,202 identified structures. We applied K-functions and Kernel smoothing to detect clustering. We confirmed the clustering using Kulldorff's spatial scan statistic. A total of 14,222 cases and 225 deaths were reported in the country (AR = 0.94%, CFR = 1.64%. The more affected regions were Biombo, Bijagos and Bissau (the capital. Bairro Bandim was the most affected neighborhood of the capital (AR = 4.0. We found at least one case in 22.7% of the houses (95%CI: 19.5-26.2 in this neighborhood. The cluster analysis identified two areas within Bairro Bandim at highest risk: a market and an intersection where runoff accumulates waste (p<0.001. CONCLUSIONS/SIGNIFICANCE: Our analysis allowed for the identification of the most affected regions in Guinea-Bissau during the 2008 cholera outbreak, and the most affected areas within the capital. This information was essential for making

  10. Haiti's progress in achieving its 10-year plan to eliminate cholera: hidden sickness cannot be cured

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    Koski-Karell V

    2016-05-01

    Full Text Available Victoria Koski-Karell,1,2 Paul E Farmer,2–4 Benito Isaac,5 Elizabeth M Campa,5 Loune Viaud,5 Paul C Namphy,6 Ralph Ternier,5 Louise C Ivers2–4 1Department of Anthropology, University of Michigan, and University of Michigan Medical School, Ann Arbor, MI, 2Partners In Health, 3Department of Global Health and Social Medicine, Harvard Medical School, 4Department of Medicine, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA, USA; 5Zanmi Lasante, Cange, 6Direction Nationale de l'Eau Potable et de l'Assainissement, Port-au-Prince, Haiti Abstract: Since the beginning of the cholera epidemic in Haiti 5 years ago, the prevalence of this deadly water-borne disease has fallen far below the initial rates registered during its explosive outset. However, cholera continues to cause extensive suffering and needless deaths across the country, particularly among the poor. The urgent need to eliminate transmission of cholera persists: compared to the same period in 2014, the first 4 months of 2015 saw three times the number of cholera cases. Drawing upon epidemiology, clinical work (and clinical knowledge, policy, ecology, and political economy, and informed by ethnographic data collected in a rural area of Haiti called Bocozel, this paper evaluates the progress of the nation's 10-year Plan for the Elimination of Cholera. Bocozel is a rice-producing region where most people live in extreme poverty. The irrigation network is decrepit, the land is prone to environmental shocks, fertilizer is not affordable, and the government's capacity to assist farmers is undermined by resource constraints. When peasants do have rice to sell, the price of domestically grown rice is twice that of US-imported rice. Canal water is not only used to irrigate thousands of acres of rice paddies and sustain livestock, but also to bathe, wash, and play, while water from wells, hand pumps, and the river is used for drinking, cooking, and bathing. Only one out of

  11. Spatial clustering in the spatio-temporal dynamics of endemic cholera

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    Emch Michael

    2010-03-01

    Full Text Available Abstract Background The spatio-temporal patterns of infectious diseases that are environmentally driven reflect the combined effects of transmission dynamics and environmental heterogeneity. They contain important information on different routes of transmission, including the role of environmental reservoirs. Consideration of the spatial component in infectious disease dynamics has led to insights on the propagation of fronts at the level of counties in rabies in the US, and the metapopulation behavior at the level of cities in childhood diseases such as measles in the UK, both at relatively coarse scales. As epidemiological data on individual infections become available, spatio-temporal patterns can be examined at higher resolutions. Methods The extensive spatio-temporal data set for cholera in Matlab, Bangladesh, maps the individual location of cases from 1983 to 2003. This unique record allows us to examine the spatial structure of cholera outbreaks, to address the role of primary transmission, occurring from an aquatic reservoir to the human host, and that of secondary transmission, involving a feedback between current and past levels of infection. We use Ripley's K and L indices and bootstrapping methods to evaluate the occurrence of spatial clustering in the cases during outbreaks using different temporal windows. The spatial location of cases was also confronted against the spatial location of water sources. Results Spatial clustering of cholera cases was detected at different temporal and spatial scales. Cases relative to water sources also exhibit spatial clustering. Conclusions The clustering of cases supports an important role of secondary transmission in the dynamics of cholera epidemics in Matlab, Bangladesh. The spatial clustering of cases relative to water sources, and its timing, suggests an effective role of water reservoirs during the onset of cholera outbreaks. Once primary transmission has initiated an outbreak, secondary

  12. Cholera and shigellosis: different epidemiology but similar responses to climate variability.

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    Benjamin A Cash

    Full Text Available Comparative studies of the associations between different infectious diseases and climate variability, such as the El Niño-Southern Oscillation, are lacking. Diarrheal illnesses, particularly cholera and shigellosis, provide an important opportunity to apply a comparative approach. Cholera and shigellosis have significant global mortality and morbidity burden, pronounced differences in transmission pathways and pathogen ecologies, and there is an established climate link with cholera. In particular, the specific ecology of Vibrio cholerae is often invoked to explain the sensitivity of that disease to climate.The extensive surveillance data of the International Center for Diarrheal Disease Research, Bangladesh are used here to revisit the known associations between cholera and climate, and to address their similarity to previously unexplored patterns for shigellosis. Monthly case data for both the city of Dhaka and a rural area known as Matlab are analyzed with respect to their association with El Niño and flooding. Linear correlations are examined between flooding and cumulative cases, as well as for flooding and El Niño. Rank-correlation maps are also computed between disease cases in the post-monsoon epidemic season and sea surface temperatures in the Pacific. Similar climate associations are found for both diseases and both locations. Increased cases follow increased monsoon flooding and increased sea surface temperatures in the preceding winter corresponding to an El Niño event.The similarity in association patterns suggests a systemic breakdown in population health with changing environmental conditions, in which climate variability acts primarily through increasing the exposure risk of the human population. We discuss these results in the context of the on-going debate on the relative importance of the environmental reservoir vs. secondary transmission, as well as the implications for the use of El Niño as an early indicator of

  13. The extracellular nuclease Dns and its role in natural transformation of Vibrio cholerae.

    Science.gov (United States)

    Blokesch, Melanie; Schoolnik, Gary K

    2008-11-01

    Free extracellular DNA is abundant in many aquatic environments. While much of this DNA will be degraded by nucleases secreted by the surrounding microbial community, some is available as transforming material that can be taken up by naturally competent bacteria. One such species is Vibrio cholerae, an autochthonous member of estuarine, riverine, and marine habitats and the causative agent of cholera, whose competence program is induced after colonization of chitin surfaces. In this study, we investigate how Vibrio cholerae's two extracellular nucleases, Xds and Dns, influence its natural transformability. We show that in the absence of Dns, transformation frequencies are significantly higher than in its presence. During growth on a chitin surface, an increase in transformation efficiency was found to correspond in time with increasing cell density and the repression of dns expression by the quorum-sensing regulator HapR. In contrast, at low cell density, the absence of HapR relieves dns repression, leading to the degradation of free DNA and to the abrogation of the transformation phenotype. Thus, as cell density increases, Vibrio cholerae undergoes a switch from nuclease-mediated degradation of extracellular DNA to the uptake of DNA by bacteria induced to a state of competence by chitin. Taken together, these results suggest the following model: nuclease production by low-density populations of V. cholerae might foster rapid growth by providing a source of nucleotides for the repletion of nucleotide pools. In contrast, the termination of nuclease production by static, high-density populations allows the uptake of intact DNA and coincides with a phase of potential genome diversification. PMID:18757542

  14. Predicting the evolution of large cholera outbreaks: lessons learnt from the Haiti case study

    Science.gov (United States)

    Bertuzzo, Enrico; Mari, Lorenzo; Righetto, Lorenzo; Knox, Allyn; Finger, Flavio; Casagrandi, Renato; Gatto, Marino; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2013-04-01

    Mathematical models can provide key insights into the course of an ongoing epidemic, potentially aiding real-time emergency management in allocating health care resources and possibly anticipating the impact of alternative interventions. Spatially explicit models of waterborne disease are made routinely possible by widespread data mapping of hydrology, road network, population distribution, and sanitation. Here, we study the ex-post reliability of predictions of the ongoing Haiti cholera outbreak. Our model consists of a set of dynamical equations (SIR-like, i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water, which are, in turn, driven by hydrologic transport through waterways and by mobility of susceptible and infected individuals. Following the evidence of a clear correlation between rainfall events and cholera resurgence, we test a new mechanism explicitly accounting for rainfall as a driver of enhanced disease transmission by washout of open-air defecation sites or cesspool overflows. A general model for Haitian epidemic cholera and the related uncertainty is thus proposed and applied to the dataset of reported cases now available. The model allows us to draw predictions on longer-term epidemic cholera in Haiti from multi-season Monte Carlo runs, carried out up to January 2014 by using a multivariate Poisson rainfall generator, with parameters varying in space and time. Lessons learned and open issues are discussed and placed in perspective. We conclude that, despite differences in methods that can be tested through model-guided field validation, mathematical modeling of large-scale outbreaks emerges as an essential component of future cholera epidemic control.

  15. An Estimation of Private Household Costs to Receive Free Oral Cholera Vaccine in Odisha, India.

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    Vittal Mogasale

    Full Text Available Service provider costs for vaccine delivery have been well documented; however, vaccine recipients' costs have drawn less attention. This research explores the private household out-of-pocket and opportunity costs incurred to receive free oral cholera vaccine during a mass vaccination campaign in rural Odisha, India.Following a government-driven oral cholera mass vaccination campaign targeting population over one year of age, a questionnaire-based cross-sectional survey was conducted to estimate private household costs among vaccine recipients. The questionnaire captured travel costs as well as time and wage loss for self and accompanying persons. The productivity loss was estimated using three methods: self-reported, government defined minimum daily wages and gross domestic product per capita in Odisha.On average, families were located 282.7 (SD = 254.5 meters from the nearest vaccination booths. Most family members either walked or bicycled to the vaccination sites and spent on average 26.5 minutes on travel and 15.7 minutes on waiting. Depending upon the methodology, the estimated productivity loss due to potential foregone income ranged from $0.15 to $0.29 per dose of cholera vaccine received. The private household cost of receiving oral cholera vaccine constituted 24.6% to 38.0% of overall vaccine delivery costs.The private household costs resulting from productivity loss for receiving a free oral cholera vaccine is a substantial proportion of overall vaccine delivery cost and may influence vaccine uptake. Policy makers and program managers need to recognize the importance of private costs and consider how to balance programmatic delivery costs with private household costs to receive vaccines.

  16. Field evaluation of a rapid immunochromatographic dipstick test for the diagnosis of cholera in a high-risk population

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    Park Taesung

    2006-02-01

    Full Text Available Abstract Background Early detection of cholera outbreaks is crucial for the implementation of the most appropriate control strategies. Methods The performance of an immunochromatographic dipstick test (Institute Pasteur, Paris, France specific for Vibrio cholerae O1 was evaluated in a prospective study in Beira, Mozambique, during the 2004 cholera season (January-May. Fecal specimens were collected from 391 patients with acute watery nonbloody diarrhea and tested by dipstick and conventional culture. Results The overall sensitivity and specificity of the rapid test compared to culture were 95% (95% confidence interval [CI]: 91%–99% and 89% (95% CI: 86%–93%, respectively. After stratification by type of sample (rectal swab/bulk stool and severity of diarrhea, the sensitivity ranged between 85% and 98% and specificity between 77% and 97%. Conclusion This one-step dipstick test performed well in the diagnosis of V. cholerae O1 in a setting with seasonal outbreaks where rapid tests are most urgently needed.

  17. Sensitivity of Vibrio cholerae cells to lethal and mutagenic effect of UV-irradiation mediated by plasmids

    International Nuclear Information System (INIS)

    The effect of UV-irradiation on Vibrio cholerae cells and its changes mediated by the plasmid R245 have been studied. Vibrio cholerae strains 569B and RV31 have been shown to be considerably more sensitive to lethal effect of UV-irradiation as compared with Escherichia coli and Salmonella typhimurium cells. Highly toxigenic strain 569B and practically atoxigenic strain RV31 have the same UV-sensitivity. Lethla effect of UV-irradiation on Vibrio cholerae cells is incresed when the irradiated cells are plated on enriched media. UV-induction of mutations was not registered in plasmidless strains of Vibrio cholerae. Plasmid R245 increase UV-resistance of vibrio cells and makes them UV-mutable

  18. Orphan nuclear receptor Nur77 is required for the differentiation of C6 glioma cells induced by cholera toxin

    Institute of Scientific and Technical Information of China (English)

    Dong XU; Yi-jun HUANG; Yan LI; Wei YIN; Guang-mei YAN

    2009-01-01

    Aim: To investigate a possible regulator gene involved in the cholera toxin-induced differentiation of rat C6 glioma cells. Methods: The global changes in the mRNA expression pattern induced by cholera toxin were analyzed using gene chip microarray. The selected gene was then silenced by RNA interference or overexpressed with an ORF plasmid to determine its necessity in this process. Results: Nur77, a member of the orphan nuclear receptor family (NR4A), was markedly up-regulated during the process of differentiation. Furthermore, RNAi of nur77 attenuated the induction effect of cholera toxin on C6 cells, whereas overexpression of nur77 led to similarly differentiated behavior, including morphologic and biomarker changes, as well as cell cycle arrest. Conclusion: Nur77 participated actively and essentially as an important regulator in the cholera toxin-induced differentiation of C6 cells.

  19. Use of a Cholera Rapid Diagnostic Test during a Mass Vaccination Campaign in Response to an Epidemic in Guinea, 2012

    Science.gov (United States)

    Martinez-Pino, Isabel; Luquero, Francisco J.; Sakoba, Kéïta; Sylla, Souleymane; Haile, Melatwork; Grais, Rebecca F.; Ciglenecki, Iza; Quilici, Marie-Laure; Page, Anne-Laure

    2013-01-01

    Background During the 2012 cholera outbreak in the Republic of Guinea, the Ministry of Health, supported by Médecins Sans Frontières - Operational Center Geneva, used the oral cholera vaccine Shanchol as a part of the emergency response. The rapid diagnostic test (RDT) Crystal VC, widely used during outbreaks, detects lipopolysaccharide antigens of Vibrio cholerae O1 and O139, both included in Shanchol. In the context of reactive use of a whole-cell cholera vaccine in a region where cholera cases have been reported, it is essential to know what proportion of vaccinated individuals would be reactive to the RDT and for how long after vaccination. Methodology/Principal Findings A total of 108 vaccinated individuals, selected systematically among all persons older than one year, were included at vaccination sites and 106 were included in the analysis. Stools samples of this cohort of vaccinated participants were collected and tested with the RDT every day until the test was negative for two consecutive visits or for a maximum of 7 days. A total of 94.3% of cholera vaccine recipients had a positive test after vaccination; all except one of these positive results were reactive only with the O139 antigen. The mean time to become negative in those with an initial positive result after vaccination was 3.8 days, standard deviation 1.1 days. Conclusions/Significance The RDT Crystal VC becomes positive in persons recently vaccinated against cholera, although almost exclusively to the O139 antigen. This reactivity largely disappeared within five days after vaccination. These results suggest that the test can be used normally as soon as 24 hours after vaccination in a context of O1 epidemics, which represent the vast majority of cases, and after a period of five days in areas where V. cholerae O139 is present. The reason why only O139 test line became positive remains to be investigated. PMID:23967359

  20. Spatio-temporal clustering of cholera: The impact of flood control in Matlab, Bangladesh, 1983–2003

    OpenAIRE

    Carrel, Margaret A.; Emch, Michael; Streatfield, Peter K; Yunus, Mohammad

    2009-01-01

    Introducing flood control to an area of endemic waterborne diseases could have significant impacts on spatio-temporal occurrence of cholera. Using 21-years of data from Bangladesh, we conducted cluster analysis to explore changes in spatial and temporal distribution of cholera incidence since 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 clusteri...

  1. A case of non-O1/non-O139 Vibrio cholerae septicemia and meningitis in a neonate.

    Science.gov (United States)

    Hao, Yingying; Wang, Yueling; Bi, Zhenwang; Sun, Baixiu; Jin, Yan; Bai, Yuanyuan; Chen, Baoli; Shao, Chunhong; Sun, Xuerong; Lu, Zhiming

    2015-06-01

    A case of septicemia with meningitis due to non-O1/non-O139 Vibrio cholerae in a neonate is reported. The genotype and phenotype of the isolate were examined in relation to the major virulence genes. The isolate was shown to be non-toxin but cytotoxin-producing, distinguished from the dominant clone of non-O1/non-O139V. cholerae by multilocus sequence typing.

  2. Population Genetics of Vibrio cholerae from Nepal in 2010: Evidence on the Origin of the Haitian Outbreak

    OpenAIRE

    Hendriksen, Rene S; Price, Lance B.; Schupp, James M.; Gillece, John D.; Kaas, Rolf Sommer; Engelthaler, David M.; Bortolaia, Valeria; Pearson, Talima; Waters, Andrew E.; Prasad Upadhyay, Bishnu; Devi Shrestha, Sirjana; Adhikari, Shailaja; Shakya, Geeta; Keim, Paul S.; Aarestrup, Frank Møller

    2011-01-01

    ABSTRACT: Cholera continues to be an important cause of human infections, and outbreaks are often observed after natural disasters, such as the one following the 2010 earthquake in Haiti. Once the cholera outbreak was confirmed, rumors spread that the disease was brought to Haiti by a battalion of Nepalese soldiers serving as United Nations peacekeepers. This possible connection has never been confirmed. We used whole-genome sequence typing (WGST), pulsed-field gel electrophoresis (PFGE), and...

  3. ToxR regulates the production of lipoproteins and the expression of serum resistance in Vibrio cholerae

    International Nuclear Information System (INIS)

    The genes encoding three lipoproteins of Vibrio cholerae were identified by a combination of DNA sequence analysis and [3H]palmitate labeling of hybrid proteins encoded by TnphoA gene fusions. The expression of these three lipoproteins, TagA, AcfD, and TcpC, was controlled by ToxR, the cholera toxin transcriptional activator. The involvement of other bacterial lipoproteins in conferring resistance ot the bactericidal effects of complement prompted us to examine this possibility in V. cholerae. Remarkably, mutations in toxR and tcp genes (including tcpC), involved in the biogenesis of the toxin coregulated pili, rendered V. cholerae about 104 - 106 times more sensitive to the vibriocidal activity of antibody and complement. Since V. cholerae is a noninvasive organism and toxR and tcp mutants are highly defective in intestinal colonization in animals and humans, these results raise the possibility that resistance to a gut-associated, complement-like bactericidal activity may be a major virulence determinant of V. cholerae and other enterobacterial species

  4. Detection of Vibrio cholerae by isothermal cross-priming amplification combined with nucleic acid detection strip analysis.

    Science.gov (United States)

    Zhang, Xia; Du, Xin-Jun; Guan, Chun; Li, Ping; Zheng, Wen-Jie; Wang, Shuo

    2015-08-01

    Vibrio cholerae is a water- and food-borne human pathogen, and V. cholerae serotypes O1 and O139 have attracted attention because of their severe pathogenesis. However, non-O1, non-O139 cholera vibrios (NCVs) were also recently recognized as having virulence properties. In this study, we developed a cross-priming amplification (CPA) method for the detection of all serotypes of V. cholerae. The specificity of the CPA method was tested using a panel of 60 different bacterial strains. All of the V. cholerae strains showed positive results, and 41 other types of bacteria gave negative results. The limit of detection of the CPA method was 79.28 fg of genomic DNA, 4.2 × 10(2) CFU/ml for bacteria in pure culture, and 5.6 CFU per 25 g of sample with pre-enrichment. This method showed a higher sensitivity than the loop-mediated isothermal amplification (LAMP) method did and was more convenient to perform. These results indicate that the CPA method can be used for the rapid preliminary screening of V. cholerae.

  5. Laboratory-confirmed cholera and rotavirus among patients with acute diarrhea in four hospitals in Haiti, 2012-2013.

    Science.gov (United States)

    Steenland, Maria W; Joseph, Gerard A; Lucien, Mentor Ali Ber; Freeman, Nicole; Hast, Marisa; Nygren, Benjamin L; Leshem, Eyal; Juin, Stanley; Parsons, Michele B; Talkington, Deborah F; Mintz, Eric D; Vertefeuille, John; Balajee, S Arunmozhi; Boncy, Jacques; Katz, Mark A

    2013-10-01

    An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children.

  6. DNA damage and reactive nitrogen species are barriers to Vibrio cholerae colonization of the infant mouse intestine.

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    Bryan W Davies

    2011-02-01

    Full Text Available Ingested Vibrio cholerae pass through the stomach and colonize the small intestines of its host. Here, we show that V. cholerae requires at least two types of DNA repair systems to efficiently compete for colonization of the infant mouse intestine. These results show that V. cholerae experiences increased DNA damage in the murine gastrointestinal tract. Agreeing with this, we show that passage through the murine gut increases the mutation frequency of V. cholerae compared to liquid culture passage. Our genetic analysis identifies known and novel defense enzymes required for detoxifying reactive nitrogen species (but not reactive oxygen species that are also required for V. cholerae to efficiently colonize the infant mouse intestine, pointing to reactive nitrogen species as the potential cause of DNA damage. We demonstrate that potential reactive nitrogen species deleterious for V. cholerae are not generated by host inducible nitric oxide synthase (iNOS activity and instead may be derived from acidified nitrite in the stomach. Agreeing with this hypothesis, we show that strains deficient in DNA repair or reactive nitrogen species defense that are defective in intestinal colonization have decreased growth or increased mutation frequency in acidified nitrite containing media. Moreover, we demonstrate that neutralizing stomach acid rescues the colonization defect of the DNA repair and reactive nitrogen species defense defective mutants suggesting a common defense pathway for these mutants.

  7. Risk factors for cholera transmission in Haiti during inter-peak periods: insights to improve current control strategies from two case-control studies

    OpenAIRE

    Grandesso, F; M Allan; Jean-Simon, P S J; Boncy, J; Blake, A.; Pierre, R; Alberti, K P; Munger, A; Elder, G; Olson, D; Porten, K; F. J. Luquero

    2013-01-01

    SUMMARY Two community-based density case-control studies were performed to assess risk factors for cholera transmission during inter-peak periods of the ongoing epidemic in two Haitian urban settings, Gonaives and Carrefour. The strongest associations were: close contact with cholera patients (sharing latrines, visiting cholera patients, helping someone with diarrhoea), eating food from street vendors and washing dishes with untreated water. Protective factors were: drinking chlorinated water...

  8. The El Tor Biotype of Vibrio cholerae Exhibits a Growth Advantage in the Stationary Phase in Mixed Cultures with the Classical Biotype▿

    OpenAIRE

    Pradhan, Subhra; Baidya, Amit K.; Ghosh, Amalendu; Paul, Kalidas; Chowdhury, Rukhsana

    2009-01-01

    Vibrio cholerae strains of the O1 serogroup that typically cause epidemic cholera can be classified into two biotypes, classical and El Tor. The El Tor biotype emerged in 1961 and subsequently displaced the classical biotype as a cause of cholera throughout the world. In this study we demonstrate that when strains of the El Tor and classical biotypes were cocultured in standard LB medium, the El Tor strains clearly had a competitive growth advantage over the classical biotype starting from th...

  9. Lack of Outer Membrane Protein A Enhances the Release of Outer Membrane Vesicles and Survival of Vibrio cholerae and Suppresses Viability of Acanthamoeba castellanii

    Directory of Open Access Journals (Sweden)

    Soni Priya Valeru

    2014-01-01

    Full Text Available Vibrio cholerae, the causative agent of the diarrhoeal disease cholera, survives in aquatic environments. The bacterium has developed a survival strategy to grow and survive inside Acanthamoeba castellanii. It has been shown that V. cholerae expresses outer membrane proteins as virulence factors playing a role in the adherence to interacted host cells. This study examined the role of outer membrane protein A (OmpA and outer membrane vesicles (OMVs in survival of V. cholerae alone and during its interaction with A. castellanii. The results showed that an OmpA mutant of V. cholerae survived longer than wild-type V. cholerae when cultivated alone. Cocultivation with A. castellanii enhanced the survival of both bacterial strains and OmpA protein exhibited no effect on attachment, engulfment, and survival inside the amoebae. However, cocultivation of the OmpA mutant of V. cholerae decreased the viability of A. castellanii and this bacterial strain released more OMVs than wild-type V. cholerae. Surprisingly, treatment of amoeba cells with OMVs isolated from the OmpA mutant significantly decreased viable counts of the amoeba cells. In conclusion, the results might highlight a regulating rule for OmpA in survival of V. cholerae and OMVs as a potent virulence factor for this bacterium towards eukaryotes in the environment.

  10. The cause of P.I. Tchaikovsky's (1840-1893) death: cholera, suicide, or both?

    Science.gov (United States)

    Kornhauser, Pavle

    2010-01-01

    The death of P. I. Tchaikovsky (1840 - 1893) excites imagination even today. According to the "official scenario", Tchaikovsky had suffered from abdominal colic before being infected with cholera. On 2 November 1893, he drank a glass of unboiled water. A few hours later, he had diarrhoea and started vomiting. The following day anuria occured. He lost consciousness and died on 6 November (or on 25 Oktober according to the Russian Julian calendar). Soon after composer's death, rumors of forced suicide began to circulate. Based on the opinion of the musicologist Alexandra Orlova, the main reason for the composer's tragic fate lies in his homosexual inclination. The author of this article, after examining various sources and arguments, concludes that P. I. Tchaikovsky died of cholera.

  11. Staying Alive: Vibrio cholerae's Cycle of Environmental Survival, Transmission, and Dissemination.

    Science.gov (United States)

    Conner, Jenna G; Teschler, Jennifer K; Jones, Christopher J; Yildiz, Fitnat H

    2016-04-01

    Infectious diseases kill nearly 9 million people annually. Bacterial pathogens are responsible for a large proportion of these diseases, and the bacterial agents of pneumonia, diarrhea, and tuberculosis are leading causes of death and disability worldwide. Increasingly, the crucial role of nonhost environments in the life cycle of bacterial pathogens is being recognized. Heightened scrutiny has been given to the biological processes impacting pathogen dissemination and survival in the natural environment, because these processes are essential for the transmission of pathogenic bacteria to new hosts. This chapter focuses on the model environmental pathogen Vibrio cholerae to describe recent advances in our understanding of how pathogens survive between hosts and to highlight the processes necessary to support the cycle of environmental survival, transmission, and dissemination. We describe the physiological and molecular responses of V. cholerae to changing environmental conditions, focusing on its survival in aquatic reservoirs between hosts and its entry into and exit from human hosts. PMID:27227302

  12. Evaluation of Peru-15, a new live oral vaccine for cholera, in volunteers.

    Science.gov (United States)

    Sack, D A; Sack, R B; Shimko, J; Gomes, G; O'Sullivan, D; Metcalfe, K; Spriggs, D

    1997-07-01

    A new live oral cholera vaccine, Peru-15, was studied for safety, immunogenicity, and excretion in 2 groups of healthy volunteers. Twelve inpatient volunteers received freshly harvested vaccine in doses of either 10(7) or 10(9) cfu. Subsequently 50 outpatient volunteers received freeze-dried vaccine in doses of 10(8) or 10(9) cfu or placebo in a three-cell, double-masked, placebo-controlled trial. The strain was well tolerated at all dose levels, and it stimulated high levels of vibriocidal antibodies in most inpatient volunteers and in all outpatient volunteers. Although antitoxin responses were less frequent and of lower magnitude than the vibriocidal responses, antitoxin responses were seen in >60% of the outpatient volunteers. About 60% of the volunteers excreted the vaccine in their feces; however, fecal excretion did not correlate with serologic responses. It is concluded that Peru-15 is a safe and immunogenic oral vaccine for cholera.

  13. Cholera toxin entry into pig enterocytes occurs via a lipid raft- and clathrin-dependent mechanism

    DEFF Research Database (Denmark)

    Hansen, Gert H; Dalskov, Stine-Mathilde; Rasmussen, Christina Rehné;

    2005-01-01

    The small intestinal brush border is composed of lipid raft microdomains, but little is known about their role in the mechanism whereby cholera toxin gains entry into the enterocyte. The present work characterized the binding of cholera toxin B subunit (CTB) to the brush border and its...... that membrane cholesterol is not required for toxin binding and entry. The ganglioside GM(1) is known as the receptor for CTB, but surprisingly the toxin also bound to sucrase-isomaltase and coclustered with this glycosidase in apical membrane pits. CTB binds to lipid rafts of the brush border...... accompanied the toxin internalization whereas no formation of caveolae was observed. CTB was strongly associated with the buoyant, detergent-insoluble fraction of microvillar membranes. Neither CTB's raft association nor uptake via clathrin-coated pits was affected by methyl-beta-cyclodextrin, indicating...

  14. Elimination of Vibrio Cholerae, El Tor, in crawfish tails (Penaeus vannamei) by ionizing radiation

    International Nuclear Information System (INIS)

    V. cholerae decimal reduction dose (D10), the optimal radiation dose to extend life span of crawfish tails kept at 2oC, has been established by means of microbiological, organoleptic and chemical tests. V. Cholerae D10 value was found to be 0,107 kGy in crawfish tails and 0,127 kGy in peptone saline solution, the optimal radiation dose being 2 kGy, reducing the microbial concentration from 1,7 x 106 to 6,2 x 103 CFU/g and extending its 9-day life span to 20 days, in control samples. At 3 kGy the microbial concentration is reduced in 3 logarithmic cycles, but the organoleptic characteristics are modified in smell and flavor. It was also found that organoleptic tests prevailed over the microbiological and chemical ones with regard to product acceptance

  15. Overexpression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae EpsG

    International Nuclear Information System (INIS)

    Recombinant V. cholerae EpsG has been expressed, purified and crystallized. The crystals diffracted to 2.26 Å resolution. EpsG is the major pseudopilin protein of the Vibrio cholerae type II secretion system. An expression plasmid that encodes an N-terminally truncated form of EpsG with a C-terminal noncleavable His tag was constructed. Recombinant EpsG was expressed in Escherichia coli; the truncated protein was purified and crystallized by hanging-drop vapor diffusion against a reservoir containing 6 mM zinc sulfate, 60 mM MES pH 6.5, 15% PEG MME 550. The crystals diffracted X-rays to a resolution of 2.26 Å and belonged to space group P21, with unit-cell parameters a = 88.61, b = 70.02, c = 131.54 Å

  16. Expression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae pseudopilin EpsH

    International Nuclear Information System (INIS)

    Recombinant V. cholerae EpsH has been expressed, purified and crystallized. The crystals diffracted to 1.71 Å resolution. EpsH is a minor pseudopilin protein of the Vibrio cholerae type II secretion system. A truncated form of EpsH with a C-terminal noncleavable His tag was constructed and expressed in Escherichia coli, purified and crystallized by sitting-drop vapor diffusion. A complete data set was collected to 1.71 Å resolution. The crystals belonged to space group P212121, with unit-cell parameters a = 53.39, b = 71.11, c = 84.64 Å. There were two protein molecules in the asymmetric unit, which gave a Matthews coefficient VM of 2.1 Å3 Da−1, corresponding to 41.5% solvent content

  17. Repair of ultraviolet-light-induced DNA damage in Vibrio cholerae

    International Nuclear Information System (INIS)

    Repair of ultraviolet-light-induced DNA damage in a highly pathogenic Gram-negative bacterium, Vibrio cholerae, has been examined. All three strains of V. cholerae belonging to two serotypes, Inaba and Ogawa, are very sensitive to ultraviolet irradiation, having inactivation cross-sections ranging from 0.18 to 0.24 m2/J. Although these cells are proficient in repairing the DNA damage by a photoreactivation mechanism, they do not possess efficient dark repair systems. The mild toxinogenic strain 154 of classical Vibrios presumably lacks any excision repair mechanism and studies of irradiated cell DNA indicate that the ultraviolet-induced pyrimidine dimers may not be excised. Ultraviolet-irradiated cells after saturation of dark repair can be further photoreactivated. (Auth.)

  18. Outbreak of avian cholera on the wintering grounds of the Mississippi Valley Canada goose flock

    Science.gov (United States)

    Windingstad, R.M.; Duncan, R.M.; Thornburg, D.

    1983-01-01

    Avian cholera is reported for the first time in Canada geese, Branta canadensis, of the Mississippi Valley population. The disease was detected in weekly surveillance transects and was responsible for the loss of about 850 geese during the winter of 1978-1979 at localized areas in southern Illinois. Necropsies performed on 480 geese that died at Union County Conservation Area and on 133 birds at Horseshoe Lake Conservation Area during January and February 1979 revealed that the majority of losses (64%) were caused by avian cholera. Lead poisoning was responsible for the death of 14% of the geese analyzed and the remaining 22%, most of which were decomposed, were undiagnosed. Lethal lead levels and Pasteurella multocida occurred concomitantly in a few instances.

  19. The Potential of Bdellovibrio For the Biocontrol of the Infectious Agent Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Natalia Olsson Markelova

    2015-12-01

    Full Text Available Members of the genus Bdellovibrio are small and highly motile Gram-negative predators of other Gram-negative bacteria. Bdellovibrio enters the prey cell, transforming it into a structure that is referred to as a bdelloplast. It then grows and divides inside the bdelloplast, ending in lysis and the release of the Bdellovibrio progeny. Because of this capability, Bdellovibrio is a potential antibacterial agent. In this article, we report the results of studies on the interactions of Bdellovibrio with actively growing and viable but nonculturable (VBNC Vibrio cholerae. A significant observation was that Bdellovibrio attacked both VBNC and actively growing V. cholerae. These results indicate that Bdellovibrio, a “living antibiotic,” has potential as an antibacterial agent in environmental and public health bioprotection.

  20. Tainted commons, public health: the politico-moral significance of cholera in Vietnam.

    Science.gov (United States)

    Lincoln, Martha L

    2014-09-01

    In October 2007, a series of cholera epidemics broke out in Hanoi, interrupting a moment of economic triumphalism in post-transition Vietnam. In seeking the source of a refractory disease associated with poverty and underdevelopment, officials, media, and citizens not only identified scapegoats and proposed solutions, they also endorsed particular visions of moral conduct, social order, and public health. Controversy over cholera, a potent politico-moral symbol, expressed an imaginary of "tainted commons" (i.e., an emergent space of civil society and small-scale entrepreneurship from which the state has partially withdrawn, while still exercising some measure of scrutiny and control). The ambiguities of this situation permitted the state to assume moral postures, evade responsibility, and deflect criticism to convenient targets. Prevalent outbreak narratives thus played on anxieties regarding specifically classed and gendered social groups, whose behavior was imagined to contravene ideals of public health and order. PMID:24474525

  1. Mucosal Immunization with Helicobacter, CpG DNA, and Cholera Toxin Is Protective

    OpenAIRE

    Jiang, Weiwen; Baker, Henry J.; Smith, Bruce F.

    2003-01-01

    The mucosal delivery of antigens requires an effective adjuvant to induce mucosal immunity. Current mucosal adjuvants include cholera toxin (CT) and Escherichia coli heat-labile toxin. Unmethylated CpG immunostimulatory oligodeoxynucleotides (ODNs) have been proposed as novel mucosal adjuvants. In this study, mice were immunized with sonicated Helicobacter felis with CT and/or CpG ODN adjuvants. All groups receiving either adjuvant singly or in combination developed increased serum anti-H. fe...

  2. Berberine inhibits intestinal secretory response of Vibrio cholerae and Escherichia coli enterotoxins.

    OpenAIRE

    Sack, R B; Froehlich, J L

    1982-01-01

    Berberine, an alkaloid from the plant Berberis aristata, which has been known since ancient times as an antidiarrheal medication in India and China, inhibited by approximately 70% the secretory responses of the heat-labile enterotoxins of Vibrio cholerae and Escherichia coli in the rabbit ligated intestinal loop model. The drug was effective when given either before or after enterotoxin binding and when given either intraluminally or parenterally; it did not inhibit the stimulation of adenyla...

  3. Vibrio parahaemolyticus, enterotoxigenic Escherichia coli, enterohemorrhagic Escherichia coli and Vibrio cholerae

    OpenAIRE

    Takeda, Yoshifumi

    2011-01-01

    This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure–activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) produced by enterohemorrhagic Escherichia coli O157:H7, (iv) discovery of Vibrio cholerae O139, (v) ...

  4. Differential Management of the Replication Terminus Regions of the Two Vibrio cholerae Chromosomes during Cell Division

    OpenAIRE

    Gaëlle Demarre; Elisa Galli; Leila Muresan; Evelyne Paly; Ariane David; Christophe Possoz; François-Xavier Barre

    2014-01-01

    The replication terminus region (Ter) of the unique chromosome of most bacteria locates at mid-cell at the time of cell division. In several species, this localization participates in the necessary coordination between chromosome segregation and cell division, notably for the selection of the division site, the licensing of the division machinery assembly and the correct alignment of chromosome dimer resolution sites. The genome of Vibrio cholerae, the agent of the deadly human disease choler...

  5. Grape extracts inhibit multiple events in the cell biology of cholera intoxication.

    Directory of Open Access Journals (Sweden)

    Srikar Reddy

    Full Text Available Vibrio cholerae produces cholera toxin (CT, an AB5 protein toxin that is primarily responsible for the profuse watery diarrhea of cholera. CT is secreted into the extracellular milieu, but the toxin attacks its Gsα target within the cytosol of a host cell. Thus, CT must cross a cellular membrane barrier in order to function. This event only occurs after the toxin travels by retrograde vesicular transport from the cell surface to the endoplasmic reticulum (ER. The catalytic A1 polypeptide then dissociates from the rest of the toxin and assumes an unfolded conformation that facilitates its transfer to the cytosol by a process involving the quality control system of ER-associated degradation. Productive intoxication is blocked by alterations to the vesicular transport of CT and/or the ER-to-cytosol translocation of CTA1. Various plant compounds have been reported to inhibit the cytopathic activity of CT, so in this work we evaluated the potential anti-CT properties of grape extract. Two grape extracts currently sold as nutritional supplements inhibited CT and Escherichia coli heat-labile toxin activity against cultured cells and intestinal loops. CT intoxication was blocked even when the extracts were added an hour after the initial toxin exposure. A specific subset of host-toxin interactions involving both the catalytic CTA1 subunit and the cell-binding CTB pentamer were affected. The extracts blocked toxin binding to the cell surface, prevented unfolding of the isolated CTA1 subunit, inhibited CTA1 translocation to the cytosol, and disrupted the catalytic activity of CTA1. Grape extract could thus potentially serve as a novel therapeutic to prevent or possibly treat cholera.

  6. Phenotypic diversity of toxigenic Vibrio cholerae O1 E1 Tor strains identified in China

    Institute of Scientific and Technical Information of China (English)

    赵璇

    2014-01-01

    Objective To understand the phenotypic diversity of toxigenic Vibrio cholerae O1 E1 Tor strains isolated from different provinces in China during the last 50 years.Methods Traditional biotyping testings including susceptibility to polymyxin B,sensitivity to groupⅣphage,Voges-Proskauer test and haemolysis of sheep erythrocytes were conducted.Results Data from Biotype-specific phenotype analysis revealed that only 133 isolates carried the typical E1 Tor phenotypes while the other 251

  7. Characteristics of Vibrio cholerae O1 isolated from water of the River Ganga, Varanasi, India

    Directory of Open Access Journals (Sweden)

    S S Mohaptra

    2015-01-01

    Full Text Available Background: Vibrio cholerae is an autochthonous inhabitant of fresh and brackish water and estuarine system. Investigation of V. cholerae from the River Ganga seems important to find variation in CTX arrangement and genomic diversity. Objectives: To investigate V. cholerae O1 strains for the presence of virulence and regulatory genes, variation in number and organisation of the pre-CTXΦ and/or CTXΦ, and for the genomic diversity. Materials and Methods: Polymerase chain reaction (PCR was used to detect virulence and regulatory genes, type of rstR and location of CTXΦ on the chromosome. Southern hybridisation was conducted to see the number and arrangement of pre-CTXΦ and CTXΦ. Ribotyping and pulsed-field gel electrophoresis were used to find genetic relatedness. Results: Seven strains gave positive results by PCR for the gene encoding for ctx A, zot, ace, tcp A (El Tor, omp U, and tox R, except one strain that was negative for the ctx A. Three strains were positive for the tcp A (El Tor, omp U and tox R genes. Determination of CTX organisation showed that among the ctx-positive strains, four harboured two copies of CTXETΦ arranged in tandem and two harboured one copy of CTXETΦ, and one ctx-negative strain harboured only one copy of pre-CTXETΦ. Pulsotype and ribotype analysis showed existence of at least three pulsotype and ribotypes indicating diversity in genomic content among them. Conclusion: This study thus indicates that multiple clones (ribotypes/pulsotypes of V. cholerae O1 carrying pre-CTXΦ and/or CTXΦ and ctx-negative strains were present in the water of the River Ganga, Varanasi, India.

  8. Post-licensure deployment of oral cholera vaccines: a systematic review

    OpenAIRE

    Martin, Stephen; Lopez, Anna Lena; Bellos, Anna; Deen, Jacqueline; Ali, Mohammad; Alberti, Kathryn; Anh, Dang Duc; Costa, Alejandro; Grais, Rebecca F.; Legros, Dominique; Francisco J Luquero; Ghai, Megan B; Perea, William; Sack, David A.

    2014-01-01

    Abstract Objective To describe and analyse the characteristics of oral cholera vaccination campaigns; including location, target population, logistics, vaccine coverage and delivery costs. Methods We searched PubMed, the World Health Organization (WHO) website and the Cochrane database with no date or language restrictions. We contacted public health personnel, experts in the field and in ministries of health and did targeted web searches. Findings A total of 33 documents were included in the...

  9. N-Glycosylation of cholera toxin B subunit: serendipity for novel plant-made vaccines?

    OpenAIRE

    Nobuyuki eMatoba

    2015-01-01

    The non-toxic B subunit of cholera toxin (CTB) has attracted considerable interests from vaccinologists due to strong mucosal immunomodulatory effects and potential utility as a vaccine scaffold for heterologous antigens. Along with other conventional protein expression systems, various plant species have been used as recombinant production hosts for CTB and its fusion proteins. However, it has recently become clear that the protein is N-glycosylated within the endoplasmic reticulum of plant ...

  10. Urban Cholera transmission hotspots and their implications for Reactive Vaccination: evidence from Bissau city, Guinea Bissau

    OpenAIRE

    Azman, Andrew S.; Francisco J Luquero; Amabelia Rodrigues; Pedro Pablo Palma; Grais, Rebecca F.; Cunhate Na Banga; Grenfell, Bryan T.; Justin Lessler

    2012-01-01

    BACKGROUND: Use of cholera vaccines in response to epidemics (reactive vaccination) may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of...

  11. Epidemic cholera in Ecuador: multidrug-resistance and transmission by water and seafood

    OpenAIRE

    Weber, J. T.; Mintz, E. D.; Cañizares, R.; Semiglia, A.; Gomez, I.; Sempértegui, R.; Dávila, A.; GREENE, K. D.; Puhr, N D; Cameron, D N; Tenover, F C; Barrett, T. J.; Bean, N. H.; C. Ivey; Tauxe, R. V.

    1994-01-01

    To determine risk factors for cholera in an epidemic-disease area in South America, a case—control investigation was performed in Guayaquil, Ecuador, in July 1991. Residents > 5 years old who were hospitalized for treatment of acute, watery diarrhoea and two matched controls for each were interviewed regarding sources of water and food, and eating, drinking, and hygienic habits. Interviewers inspected homes of case-patients and controls to document water treatment, food-handling, and hygienic...

  12. FtsK-dependent dimer resolution on multiple chromosomes in the pathogen Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Marie-Eve Val

    Full Text Available Unlike most bacteria, Vibrio cholerae harbors two distinct, nonhomologous circular chromosomes (chromosome I and II. Many features of chromosome II are plasmid-like, which raised questions concerning its chromosomal nature. Plasmid replication and segregation are generally not coordinated with the bacterial cell cycle, further calling into question the mechanisms ensuring the synchronous management of chromosome I and II. Maintenance of circular replicons requires the resolution of dimers created by homologous recombination events. In Escherichia coli, chromosome dimers are resolved by the addition of a crossover at a specific site, dif, by two tyrosine recombinases, XerC and XerD. The process is coordinated with cell division through the activity of a DNA translocase, FtsK. Many E. coli plasmids also use XerCD for dimer resolution. However, the process is FtsK-independent. The two chromosomes of the V. cholerae N16961 strain carry divergent dimer resolution sites, dif1 and dif2. Here, we show that V. cholerae FtsK controls the addition of a crossover at dif1 and dif2 by a common pair of Xer recombinases. In addition, we show that specific DNA motifs dictate its orientation of translocation, the distribution of these motifs on chromosome I and chromosome II supporting the idea that FtsK translocation serves to bring together the resolution sites carried by a dimer at the time of cell division. Taken together, these results suggest that the same FtsK-dependent mechanism coordinates dimer resolution with cell division for each of the two V. cholerae chromosomes. Chromosome II dimer resolution thus stands as a bona fide chromosomal process.

  13. Effect of cholera enterotoxin on carbohydrate metabolism in the liver and small intestinal mucosa of rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Vengrov, P.R.; Cherkasova, T.D.; Yurkiv, V.A.; Pokrovskii, V.I.

    1987-09-01

    The effect of cholera enterotoxin injected in vivo on glucose formation from alanine, and also on glucose-6-phosphatase activity in the liver and mucosa of the small intestine was studied. L-(2,3-/sup 3/H)-alanine was added to the incubation medium. Chromatograms were developed with 5% AgNO/sub 3/ with the addition of an aqueous solution of ammonia. The quantity of radioactive glucose was determined in a scintillation counter.

  14. Availability of safe drinking-water: the answer to cholera outbreak? Nabua, Camarines Sur, Philippines, 2012

    Directory of Open Access Journals (Sweden)

    Alethea De Guzman

    2015-08-01

    Full Text Available Background: In May 2012, there were increasing diarrhoea cases and deaths reported from Nabua, Camarines Sur to the Philippines event-based surveillance system. An investigation was conducted to identify risk factors and determine transmission dynamics. Methods: A suspected case was defined as a resident of Nabua with at least three episodes of watery diarrhoea per day from 16 March to 22 June 2012. A confirmed case was defined as a suspected case positive for Vibrio cholerae. An environmental investigation was conducted and rectal swabs and water samples sent to the national reference laboratory for bacterial isolation. A 1:2 case-control study matching for age and sex was conducted. Data were analyzed using Epi Info. Results: There were 309 suspected cases with two deaths, and the most affected age group was children under five years (45%. Eight cases were positive for Vibrio cholerae Ogawa El Tor and one for Non-01. Water samples were positive for faecal coliforms and Aeromonas caviae. The case-control study showed that cases had a higher odds than controls of using unchlorinated water sources (odds ratio [OR] = 3.6; 95% confidence interval [CI]:1.6–8.5 and having toilets located within 20 metres of a septic tank (OR = 2.7; 95% CI: 1.4–5.3. In multivariate analysis, the only significant factor was drinking from piped water (OR = 0.21; 95% CI: 0.09–0.49. Discussion: In this cholera outbreak, drinking-water from unchlorinated wells was a significant risk factor. Future cholera control efforts should include not just improving water and sanitation systems but also intensified behaviour change campaigns.

  15. Quantitative and qualitative analysis of the knowledge, attitudes and social representations of cholera in the extreme northern region of Cameroon: the case of Maroua I, Maroua Ii And Mokolo

    OpenAIRE

    Amaah, Penn

    2014-01-01

    Introduction An effective fight against cholera requires an in-depth consideration of the knowledge, attitudes and social representations of cholera within a population. Cholera outbreaks persist in the Extreme North of Cameroon because of the inadequate integration of representations of cholera, water and hygiene in the fight against this disease. Through a constructivist intercultural approach not conflicting with the western ethnocentric model, socio-cultural/religious and historical ideol...

  16. The 2.3 {angstrom} crystal structure of cholera toxin B subunit pentamer: Choleragenoid

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L. [Argonne National Lab., IL (United States); Maulik, P.R.; Reed, R.A.; Shipley, G. [Boston Univ., MA (United States). School of Medicine; Westbrook, E.M. [Argonne National Lab., IL (United States)]|[Northwestern Univ., Evanston, IL (United States); Scott, D.L.; Otwinowski, Z. [Yale Univ., New Haven, CT (United States)

    1996-02-01

    Cholera toxin, a heterohexameric AB{sub 5} enterotoxin released by Vibrio cholera, induces a profuse secretory diarrhea in susceptible hosts. Choleragenoid, the B subunit pentamer of cholera toxin, directs the enzymatic A subunit to its target by binding to GM{sub 1} gangliosides exposed on the luminal surface of intestinal epithelial cells. We have solved the crystal structure of choleragenoid at 2.3 {Angstrom} resolution by combining single isomorphous replacement with non-crystallographic symmetry averaging. The structure of the B subunits, and their pentameric arrangement, closely resembles that reported for the intact holotoxin (choleragen), the heat-labile enterotoxin from E. coli, and for a choleragenoid-GM{sub 1} pentasaccharide complex. In the absence of the A subunit the central cavity of the B pentamer is a highly solvated channel. The binding of the A subunit or the receptor pentasaccharide to choleragenoid has only a modest effect on the local stereochemistry and does not perceptibly alter the subunit interface.

  17. Multi-scale molecular dynamics study of cholera pentamer binding to a GM1-phospholipid membrane.

    Science.gov (United States)

    Sridhar, Akshay; Kumar, Amit; Dasmahapatra, Ashok Kumar

    2016-07-01

    The AB5 type toxin produced by the Vibrio cholerae bacterium is the causative agent of the cholera disease. The cholera toxin (CT) has been shown to bind specifically to GM1 glycolipids on the membrane surface. This binding of CT to the membrane is the initial step in its endocytosis and has been postulated to cause significant disruption to the membrane structure. In this work, we have carried out a combination of coarse-grain and atomistic simulations to study the binding of CT to a membrane modelled as an asymmetrical GM1-DPPC bilayer. Simulation results indicate that the toxin binds to the membrane through only three of its five B subunits, in effect resulting in a tilted bound configuration. Additionally, the binding of the CT can increase the area per lipid of GM1 leaflet, which in turn can cause the membrane regions interacting with the bound subunits to experience significant bilayer thinning and lipid tail disorder across both the leaflets. PMID:27474868

  18. A Label-Free Photoluminescence Genosensor Using Nanostructured Magnesium Oxide for Cholera Detection

    Science.gov (United States)

    Patel, Manoj Kumar; Ali, Md. Azahar; Krishnan, Sadagopan; Agrawal, Ved Varun; Al Kheraif, Abdulaziz A.; Fouad, H.; Ansari, Z. A.; Ansari, S. G.; Malhotra, Bansi D.

    2015-11-01

    Nanomaterial-based photoluminescence (PL) diagnostic devices offer fast and highly sensitive detection of pesticides, DNA, and toxic agents. Here we report a label-free PL genosensor for sensitive detection of Vibrio cholerae that is based on a DNA hybridization strategy utilizing nanostructured magnesium oxide (nMgO; size >30 nm) particles. The morphology and size of the synthesized nMgO were determined by transmission electron microscopic (TEM) studies. The probe DNA (pDNA) was conjugated with nMgO and characterized by X-ray photoelectron and Fourier transform infrared spectroscopic techniques. The target complementary genomic DNA (cDNA) isolated from clinical samples of V. cholerae was subjected to DNA hybridization studies using the pDNA-nMgO complex and detection of the cDNA was accomplished by measuring changes in PL intensity. The PL peak intensity measured at 700 nm (red emission) increases with the increase in cDNA concentration. A linear range of response in the developed PL genosensor was observed from 100 to 500 ng/μL with a sensitivity of 1.306 emi/ng, detection limit of 3.133 ng/μL and a regression coefficient (R2) of 0.987. These results show that this ultrasensitive PL genosensor has the potential for applications in the clinical diagnosis of cholera.

  19. Purification, crystallization and preliminary X-ray crystallographic analysis of TssL from Vibrio cholerae

    Science.gov (United States)

    Jeong, Jae-Hee; Chang, Jeong Ho; Kim, Yeon-Gil

    2014-01-01

    The type VI secretion system (T6SS) is a macromolecular complex that is conserved in Gram-negative bacteria. The T6SS secretes effector proteins into recipient cells in a contact-dependent manner in order to accomplish cooperative and competitive interactions with the cells. Although the composition and mechanism of the T6SS have been intensively investigated across many Gram-negative bacteria, to date structural information on T6SS components from the important pathogen Vibrio cholerae has been rare. Here, the cloning, purification, crystallization and preliminary X-ray crystallographic analysis of the cytoplasmic domain of TssL, an inner membrane protein of the T6SS, from V. cholerae are reported. Diffraction data were collected to 1.5 Å resolution using synchrotron radiation. The crystal belonged to the hexagonal space group P61, with unit-cell parameters a = 78.4, b = 78.4, c = 49.5 Å. The successful structural characterization of TssL from V. cholerae will contribute to understanding the role of the membrane-associated subunits of the T6SS in more detail. PMID:25195905

  20. Development of a live, oral, attenuated vaccine against El Tor cholera.

    Science.gov (United States)

    Taylor, D N; Killeen, K P; Hack, D C; Kenner, J R; Coster, T S; Beattie, D T; Ezzell, J; Hyman, T; Trofa, A; Sjogren, M H

    1994-12-01

    Vibrio cholerae El Tor strains from Peru, Bangladesh, and Bahrain were attenuated by deletion of a genetic element that encodes virulence factors and RS1. The B subunit of ctx (ctxB) was reintroduced into the recA gene of the deletion mutants, rendering them unable to recombine with exogenous genetic elements and generating Peru-3, Bang-3, and Bah-3. Fifteen volunteers received one dose of various vaccine strains at 4 x 10(6) to 1 x 10(8) cfu. All strains colonized the gut. A > or = 4-fold rise in vibriocidal titer was observed in 14 volunteers, with titers of > or = 1600 in 13. Peru-3 was the least reactogenic, but 2 of 6 volunteers had loose stools. Peru-14, a filamentous motility-deficient mutant of Peru-3, was well tolerated and colonized 18 of 21 volunteers at doses of 2 x 10(6) to 1 x 10(9) cfu. Also, when 8 Peru-3 or Peru-5 vaccinees, 5 Peru-14 vaccinees, and 8 controls were challenged with 2 x 10(6) cfu V. cholerae El Tor Inaba (N16961), 11 vaccinees were protected compared with no controls. Peru-14 shows promise as a safe, effective, single-dose oral vaccine against El Tor cholera.