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Sample records for cholera toxin

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. Role of 6-Gingerol in Reduction of Cholera Toxin Activity In Vitro and In Vivo

    OpenAIRE

    Saha, Pallashri; Das, Bornita; Chaudhuri, Keya

    2013-01-01

    Vibrio cholerae is one of the major bacterial pathogens responsible for the devastating diarrheal disease called cholera. Chemotherapy is often used against V. cholerae infections; however, the emergence of V. cholerae with multidrug resistance (MDR) toward the chemotherapeutic agents is a serious clinical problem. This scenario has provided us with the impetus to look into herbal remediation, especially toward blocking the action of cholera toxin (CT). Our studies were undertaken to determin...

  8. 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

  9. 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 the cell membrane. This involves a large number (17 million per cell) of high affinity binding sites which belong to a single class. Binding of biologically active 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 in the isolated cells. The response (elevation of cellular cAMP) of the enterocytes to cholera toxin is linear with time for 40-50 min and causes a six- to eight-fold increase over control levels at steady stae. cAMP and agents that increase cAMP production inhibit Cl--independent Na+ influx into the isolated enterocytes whereas chlorporomazine (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 into the enterocytes provides evidence for a cAMP-mediated control of intestinal Na+ uptake, which may represent the mechanistic basis for the antiabsorptive effect of CT and Na+ during induction of intestinal secretion. The effect of cAMP on Na+ but no Cl- influx in our villus cell preparation can be partially explained in terms of a cAMP-regulated Na+/H+ neutral exchange system

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we...... report that CTB binds cell surface glycoproteins. Relative contributions of gangliosides and glycoproteins to CTB binding depend on cell type, and CTB binds primarily to glycoproteins in colonic epithelial cell lines. Using a metabolically incorporated photocrosslinking sugar, we identified one CTB...

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Recombinant toxin-coregulated pilus A (TcpA) as a candidate subunit cholera vaccine.

    OpenAIRE

    Somayeh Kiaie; Hamid Abtahi; Ghasem Mosayebi; MohammadYosef Alikhani; Iraj Pakzad

    2014-01-01

    Background and Objectives The toxin co-regulated pilus A (TcpA) has been described as a critical pathogenicity factor of Vibrio cholerae. TcpA is a candidate for making subunit vaccine against cholera. The aim of this study was to produce a candidate vaccine by expressing recombinant TcpA in E. coli. Materials and Methods In this study, the toxin co-regulated pilus A gene from EL-Tor, V. cholerae subspecies, was amplified by PCR and sub-cloned into prokaryotic expression vector pGEX4T1. E. co...

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

    Science.gov (United States)

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

    2015-12-01

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

  17. Identification in traditional herbal medications and confirmation by synthesis of factors that inhibit cholera toxin-induced fluid accumulation

    OpenAIRE

    Oi, Hiroshi; Matsuura, Daisuke; Miyake, Masami; Ueno, Masamiti; Takai, Izumi; Yamamoto, Takeshi; Kubo, Masayoshi; Moss, Joel; Noda, Masatoshi

    2002-01-01

    Kampo formulations are traditional herbal medications used in China and Japan for many centuries to treat diarrheal diseases such as cholera. Our studies were undertaken to identify and verify by chemical synthesis the active components that inhibited cholera toxin (CT), the virulence factor secreted by Vibrio cholerae, the causative agent of cholera. The Kampo formulation, Daio-kanzo-to, inhibited CT activities (i.e., ADP-ribosylation, Chinese hamster ovary cell elongation); in Daio-kanzo-to...

  18. Recombinant toxin-coregulated pilus A (TcpA as a candidate subunit cholera vaccine.

    Directory of Open Access Journals (Sweden)

    Somayeh Kiaie

    2014-04-01

    Full Text Available The toxin co-regulated pilus A (TcpA has been described as a critical pathogenicity factor of Vibrio cholerae. TcpA is a candidate for making subunit vaccine against cholera. The aim of this study was to produce a candidate vaccine by expressing recombinant TcpA in E. coli.In this study, the toxin co-regulated pilus A gene from EL-Tor, V. cholerae subspecies, was amplified by PCR and sub-cloned into prokaryotic expression vector pGEX4T1. E. coli BL21 (DE3 was transformed with pGEX4T1- TcpA and gene expression was induced by IPTG and purified by GST resin. The integrity of the product was confirmed by Western blot analysis using a standard rabbit anti-V. cholerae antibody. Sera reactivity of infected individuals was further analyzed against the recombinant TcpA protein.The concentration of purified recombinant protein was calculated to be 8 mg/L of initial culture. The integrity of product was confirmed by Western blot analysis using a standard rabbit anti V. cholerae antibody. Sera reactivity of infected individual was further analyzed against the recombinant TcpA protein. The obtained data indicated that recombinant TcpA protein from V. cholerae was recognized by patient serum and animal sera.These results show that the recombinant TcpA is antigenic and could be used in a carrier host as an oral vaccine against cholera.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-15

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

  20. Targeted vaccine adjuvants based on modified cholera toxin.

    Science.gov (United States)

    Lycke, Nils

    2005-09-01

    The present review describes immunomodulation with targeted adjuvants that will allow for the development of efficacious mucosal vaccines. We have studied cholera toxin (CT) and derivatives thereof, to rationally design vaccine adjuvant vectors that are both highly efficacious as well as safe and non-toxic. Two strategies were exploited; the first using CT or the enzymatically inactive receptor-binding B-subunit of CT (CTB) and the second, using CTA1 or an enzymatically inactive mutant CTA1R7K., that was linked, in a fusion protein, to the B-cell targeting moiety, DD, from Staphylococcus areus proteinA. Our studies provide compelling evidence that delivery of Ag in the absence of ADP-ribosylation can promote tolerance, whereas, ADP-ribosyltransferase-active conjugates, prevent tolerance but induce IgA immunity. Our analysis revealed unique subsets of mucosal and systemic DC that appeared to be responsible for the ADP-ribosyltransferase sensitive dichotomy between tolerance and IgA immunity. Whether targeting of B cells suffice for tolerance-induction or requires participation of DCs, is at present an unresolved issue. Nevertheless, enzymatic modulation differentiates and matures the DC to promote CD4 T cell help for IgA B cell development. Ag-presentation in the absence of enzyme, as seen with CTA1R7K-DD, expands specific T cells to a similar extent as enzymatically active CTA1-DD, but fails to recruit help for germinal center expansion of activated B cells. We have given special attention to the genes that adjuvants turn on using Affymetrix technology. In particular, modulation of the expression of co-stimulatory molecules on the targeted APC; CD80, CD86, CD83 and B7RP-1, play important roles for the effect of the ADP-ribosylating CTA1-based adjuvants for the development of tolerance or active IgA immunity. PMID:16178769

  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. Ingestion of yogurt containing Lactobacillus acidophilus and Bifidobacterium to potentiate immunoglobulin A responses to cholera toxin in mice.

    Science.gov (United States)

    Tejada-Simon, M V; Lee, J H; Ustunol, Z; Pestka, J J

    1999-04-01

    Lactic acid bacteria have been reported to have benefits for the prevention and treatment of some forms of diarrhea and related conditions. To determine whether these effects might involve direct stimulation of the gastrointestinal immune response, we administered yogurt to try to enhance mucosal and systemic antibodies against an orally presented immunogen, cholera toxin. Yogurts were manufactured with starter cultures containing different species and strains of lactic acid bacteria. Mice were fed these yogurts for 3 wk, during which they were also orally immunized twice with 10 micrograms of cholera toxin. Blood was collected on d 0 and 21, and fecal pellets were collected weekly. Mice that were immunized orally with cholera toxin responded by producing specific intestinal and serum immunoglobulin (Ig)A anti-cholera toxin. Antibody responses of the IgA isotype were significantly increased in mice fed yogurts made with starters containing the conventional yogurt bacteria Lactobacillus bulgaricus and Streptococcus thermophilus supplemented with Lactobacillus acidophilus, Bifidobacterium bifidum, and Bifidobacterium infantis. Yogurt that was manufactured with starters containing only conventional yogurt bacteria produced less IgA anti-cholera toxin than did the control group fed nonfat dry milk. Although strong responses were also observed for IgG anti-cholera toxin in serum, the responses did not differ among groups. Thus, administration of yogurt supplemented with L. acidophilus and Bifidobacterium spp. enhanced mucosal and systemic IgA responses to the cholera toxin immunogen. PMID:10212452

  3. Cholera toxin binding affinity and specificity for gangliosides determined by surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kuziemko, G.M.; Stroh, M.; Stevens, R.C. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1996-05-21

    The present study determines the affinity of cholera toxin for the ganglioside series GM1, GM2, GM3, GD1A, GD1B, GT1B, asialo GM1, globotriosyl ceramide, and lactosyl ceramide using real time biospecific interaction analysis (surface plasmon resonance, SPR). SPR shows that cholera toxin preferably binds to gangliosides in the following sequence: GM1 > GM2 > GD1A > GM3 > GT1B > GD1B > asialo-GM1. The measured binding affinity of cholera toxin for the ganglioside sequence ranges from 4.61 {times} 10{sup {minus}12} M for GM1 to 1.88 {times} 10{sup {minus}10} M for asialo GM1. The picomolar values obtained by surface plasmon resonance are similar to K{sub d} values determined with whole-cell binding assays. Both whole-cell assays ans SPR measurements on synthetic membranes are higher than free solution measurements by several orders of magnitude. This difference may be caused by the effects of avidity and charged lipid head-groups, which may play a major role in the binding between cholera toxin, the receptor, and the membrane surface. The primary difference between free solution binding studies and surface plasmon resonance studies is that the latter technique is performed on surfaces resembling the cell membrane. Surface plasmon resonance has the further advantage of measuring apparent kinetic association and dissociation rates in real time, providing direct information about binding events at the membrane surface. 34 refs., 8 figs., 2 tabs.

  4. 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

    inserted. 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...

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

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, Bodil; Pallesen, Lars; Jensen, Lars Bogø; Christiansen, Gunnar; Klemm, Per

    inserted. 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...

  6. 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...

  7. OBTAINING OF MONOCLONAL ANTIBODIES AGAINST CHOLERA TOXIN AND HEAT LABILE ENTEROTOXIN OF E. coli FOR DEVELOPMENT OF THE TOXINS DIPLEX ANALYSIS IN ENVIRONMENTAL SPECIMENS

    Directory of Open Access Journals (Sweden)

    Eu. V. Grishin

    2013-08-01

    Full Text Available The present study focuses on development of monoclonal antibodies (MAbs which specifically interact with cholera toxin or heat labile enterotoxin of E. coli. Such monoclonal antibodies MAbs are possessed of ability to identify cholera toxin or heat labile enterotoxin in different immunochemical assays. We obtained hybridoma clones which produced monoclonal antibodies of IgG isotypes to cholera toxin and heat labile enterotoxin. On application of the method of serial dilutions we selected the clones which produced monoclonal antibodies with specific activity against only one of the toxins. We found the 16 pairs of monoclonal antibodies to cholera toxin and 28 ones to heat labile enterotoxin. By means of these monoclonal antibodies it was possible to realize the quantitative analysis of theses toxins in sandwich immunoassay ELISA and diplex sandwich xMAP-assay. The limits of detection of cholera toxin and heat labile enterotoxin in ELISA in control buffer were 0.2 and 0.4 ng/ml, respectively, and in xMAP assay — 0.01 and 0.08 ng/ml, respectively. In probes of cow milk, meat soup, pond water and nasopharyngeal washes cholera toxin was detected in the both assays with the same limits of detections, but heat labile enterotoxin limits of detections were above the ones in control buffers.

  8. 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

  9. 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.

  10. 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.

  11. 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 ...

  12. Construction of a Vibrio cholerae prototype vaccine strain O395-N1-E1 which accumulates cell-associated cholera toxin B subunit.

    Science.gov (United States)

    Rhie, Gi-eun; Jung, Hae-Mi; Kim, Bong Su; Mekalanos, John J

    2008-10-01

    Because of its production and use in Vietnam, the most widely used oral cholera vaccine consists of heat- or formalin-killed Vibrio cholerae whole cells (WC). An earlier version of this type of vaccine called whole cell-recombinant B subunit vaccine (BS-WC) produced in Sweden also contained the B subunit of cholera toxin (CTB). Both WC and BS-WC vaccines produced moderate levels of protection in field trials designed to evaluate their cholera efficacy. V. cholerae cells in these vaccines induce antibacterial immunity, and CTB contributes to the vaccine's efficacy presumably by stimulating production of anti-toxin neutralizing antibody. Although more effective than the WC vaccine, the BS-WC vaccine has not been adopted for manufacture by developing world countries primarily because the CTB component is difficult to manufacture and include in the vaccine in the doses needed to induce significant immune responses. We reasoned this was a technical problem that might be solved by engineering strains of V. cholerae that express cell-associated CTB that would co-purify with the bacterial cell fraction during the manufacture of WC vaccine. Here we report that construction of a V. cholerae O1 classical strain, O395-N1-E1, that has been engineered to accumulate CTB in the periplasmic fraction by disrupting the epsE gene of type II secretion pathway. O395-N1-E1 induces anti-CTB IgG and vibriocidal antibodies in mice immunized with two doses of formalin killed whole cells. Intraperitoneal immunization of mice with O395-N1-E1 induced a significantly higher anti-CTB antibody response compared to that of the parental strain, O395-N1. Our results suggest that this prototype cholera vaccine candidate strain may assist in preparing improved and inexpensive oral BS-WC cholera vaccine without the need to purify CTB separately. PMID:18582519

  13. The three-dimensional crystal structure of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)

    1996-02-01

    The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.

  14. Effect of in vivo injection of cholera and pertussis toxin on glucose transport in rat skeletal muscle

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Han, X; Petersen, L N; Galbo, H

    Cholera toxin (CTX) and pertussis toxin (PTX) were examined for their ability to inhibit glucose transport in perfused skeletal muscle. Twenty-five hours after an intravenous injection of CTX, basal transport was decreased approximately 30%, and insulin- and contraction-stimulated transport was...... transport, at least in part from a decrease in intramuscular GLUT-4 protein....

  15. Cholera toxin B subunit-binding and ganglioside GM1 immuno-expression are not necessarily correlated in human salivary glands

    DEFF Research Database (Denmark)

    Kirkeby, Svend

    2014-01-01

    OBJECTIVE: To determine and compare the presence and in situ localization of the glycosphingolipid ganglioside GM1 in human salivary glands using the biomarkers for GM1: cholera toxin and antibodies against GM1. MATERIALS AND METHODS: Immunohistochemical analyses were performed on sections of adult...... human submandibular, parotid and palatinal glands using cholera toxin sub-unit B and two polyclonal antibodies against ganglioside GM1 as biomarkers. RESULTS: Immunofluorescence microscopy showed that the toxin and antibodies were co-localized in some acini but not in others. The cholera toxin mainly...... plasma membranes reacted with anti-GM1. The plasma membranes in the parotid excretory ducts appeared to react to anti-GM1, but not to cholera toxin. CONCLUSIONS: Cholera toxin induces the expression of ion channels and carriers in the small intestine and increases the production of secretory mucins...

  16. 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.

  17. 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.

  18. Cholera

    Science.gov (United States)

    ... 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 ...

  19. Cholera

    Science.gov (United States)

    ... 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 ...

  20. Cholera toxin enhances vaccine-induced protection against Mycobacterium tuberculosis challenge in mice.

    Directory of Open Access Journals (Sweden)

    Kristin L Griffiths

    Full Text Available Interleukin (IL-17 is emerging as an important cytokine in vaccine-induced protection against tuberculosis disease in animal models. Here we show that compared to parenteral delivery, BCG delivered mucosally enhances cytokine production, including interferon gamma and IL-17, in the lungs. Furthermore, we find that cholera toxin, delivered mucosally along with BCG, further enhances IL-17 production by CD4(+ T cells over mucosal BCG alone both in the lungs and systemically. This boosting effect of CT is also observed using a vaccine regimen of BCG followed by the candidate vaccine MVA85A. Using a murine Mycobacterium tuberculosis (M.tb aerosol challenge model, we demonstrate the ability of cholera toxin delivered at the time of a priming BCG vaccination to improve protection against tuberculosis disease in a manner at least partially dependent on the observed increase in IL-17. This observed increase in IL-17 in the lungs has no adverse effect on lung pathology following M.tb challenge, indicating that IL-17 can safely be boosted in murine lungs in a vaccine/M.tb challenge setting.

  1. Structural and Molecular Mechanism for Autoprocessing of MARTX Toxin of Vibrio cholerae at Multiple Sites

    Energy Technology Data Exchange (ETDEWEB)

    Prochazkova, Katerina; Shuvalova, Ludmilla A.; Minasov, George; Voburka, Zden& #283; k; Anderson, Wayne F.; Satchell, Karla J.F.; (NWU); (Czech Academy)

    2009-10-05

    The multifunctional autoprocessing repeats-in-toxin (MARTX) toxin of Vibrio cholerae causes destruction of the actin cytoskeleton by covalent cross-linking of actin and inactivation of Rho GTPases. The effector domains responsible for these activities are here shown to be independent proteins released from the large toxin by autoproteolysis catalyzed by an embedded cysteine protease domain (CPD). The CPD is activated upon binding inositol hexakisphosphate (InsP{sub 6}). In this study, we demonstrated that InsP{sub 6} is not simply an allosteric cofactor, but rather binding of InsP{sub 6} stabilized the CPD structure, facilitating formation of the enzyme-substrate complex. The 1.95-{angstrom} crystal structure of this InsP{sub 6}-bound unprocessed form of CPD was determined and revealed the scissile bond Leu{sup 3428}-Ala{sup 3429} captured in the catalytic site. Upon processing at this site, CPD was converted to a form with 500-fold reduced affinity for InsP{sub 6}, but was reactivated for high affinity binding of InsP{sub 6} by cooperative binding of both a new substrate and InsP{sub 6}. Reactivation of CPD allowed cleavage of the MARTX toxin at other sites, specifically at leucine residues between the effector domains. Processed CPD also cleaved other proteins in trans, including the leucine-rich protein YopM, demonstrating that it is a promiscuous leucine-specific protease.

  2. Comparison of DOT-ELISA and Standard-ELISA for Detection of the Vibrio cholerae Toxin in Culture Supernatants of Bacteria Isolated from Human and Environmental Samples.

    Science.gov (United States)

    Meza-Lucas, Antonio; Pérez-Villagómez, María-Fernanda; Martínez-López, José-Patricio; García-Rodea, Ricardo; Martínez-Castelán, María-Guadalupe; Escobar-Gutiérrez, Alejandro; de-la-Rosa-Arana, Jorge-Luis; Villanueva-Zamudio, Altagracia

    2016-09-01

    A comparison of DOT-ELISA and Standard-ELISA was made for detection of Vibrio cholerae toxin in culture supernatants of bacteria isolated from human and environmental samples. A total of 293 supernatants were tested in a double blind assay. A correlation of 100 % was obtained between both techniques. The cholera toxin was found in 20 Inaba and 3 Ogawa strains. Positive samples were from seafood (17 samples), potable water (1 sample) and sewage (5 samples). The DOT-ELISA was useful as the standard-ELISA to confirm the presence of cholera toxin in the environmental samples. PMID:27407304

  3. 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

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

    Directory of Open Access Journals (Sweden)

    Nobuyuki eMatoba

    2015-12-01

    Full Text Available 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 cells – a eukaryotic post-translational modification that is not present in native CTB. While functionally active aglycosylated variants have been successfully engineered to circumvent potential safety and regulatory issues related to glycosylation, this modification may actually provide advantageous characteristics to the protein as a vaccine platform. Based on data from our recent studies, I discuss the unique features of N-glycosylated CTB produced in plants for the development of novel vaccines.

  5. 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

  6. Cholera Outbreaks Caused by an Altered Vibrio cholerae O1 El Tor Biotype Strain Producing Classical Cholera Toxin B in Vietnam in 2007 to 2008 ▿

    OpenAIRE

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

    2009-01-01

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

  7. Cholera Toxin Subunit B as Adjuvant––An Accelerator in Protective Immunity and a Break in Autoimmunity

    Directory of Open Access Journals (Sweden)

    Thomas Stratmann

    2015-07-01

    Full Text Available Cholera toxin subunit B (CTB is the nontoxic portion of cholera toxin. Its affinity to the monosialotetrahexosylganglioside (GM1 that is broadly distributed in a variety of cell types including epithelial cells of the gut and antigen presenting cells, macrophages, dendritic cells, and B cells, allows its optimal access to the immune system. CTB can easily be expressed on its own in a variety of organisms, and several approaches can be used to couple it to antigens, either by genetic fusion or by chemical manipulation, leading to strongly enhanced immune responses to the antigens. In autoimmune diseases, CTB has the capacity to evoke regulatory responses and to thereby dampen autoimmune responses, in several but not all animal models. It remains to be seen whether the latter approach translates to success in the clinic, however, the versatility of CTB to manipulate immune responses in either direction makes this protein a promising adjuvant for vaccine development.

  8. Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy

    DEFF Research Database (Denmark)

    Kroghsbo, S.; Christensen, Hanne Risager; Frøkiær, Hanne

    2003-01-01

    Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle immunomodu......Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle...... interested in characterizing the individual effects of the parameters in the CT-based model: CT dose, antigen type and dose, and number of immunizations. Methods: BALB/c mice were orally sensitized weekly for 3 or 7 weeks with graded doses of CT and various food antigens (soy-trypsin inhibitor, ovalbumin or...

  9. Cholera toxin disrupts barrier function by inhibiting exocyst-mediated trafficking of host proteins to intestinal cell junctions

    Science.gov (United States)

    Guichard, Annabel; Moreno, Beatriz Cruz; Aguilar, Berenice; van Sorge, Nina M.; Kuang, Jennifer; Kurkciyan, Adrianne A.; Wang, Zhipeng; Hang, Saiyu; Pineton de Chambrun, Guillaume P.; McCole, Declan F.; Watnick, Paula; Nizet, Victor; Bier, Ethan

    2013-01-01

    Summary Cholera toxin (CT), a virulence factor elaborated by Vibrio cholerae, is sufficient to induce the severe diarrhea characteristic of cholera. The enzymatic moiety of CT (CtxA) increases cAMP synthesis in intestinal epithelial cells, leading to chloride ion (Cl−) efflux through the CFTR Cl− channel. To preserve electroneutrality and osmotic balance, sodium ions and water also flow into the intestinal lumen via a paracellular route. We find that CtxA-driven cAMP increase also inhibits Rab11/exocyst-mediated trafficking of host proteins including E-cadherin and Notch signaling components to cell-cell junctions in Drosophila, human intestinal epithelial cells, and ligated mouse ileal loops, thereby disrupting barrier function. Additionally, CtxA induces junctional damage, weight loss, and dye leakage in the Drosophila gut, contributing to lethality from live V. cholerae infection, all of which can be rescued by Rab11 over-expression. These barrier-disrupting effects of CtxA may act in parallel with Cl− secretion to drive the pathophysiology of cholera. PMID:24034615

  10. Purification and characterization of Yersinia enterocolitica and Yersinia pestis LcrV–cholera toxin A2/B chimeras

    OpenAIRE

    Tinker, Juliette K.; Chadwick T Davis; Arlian, Britni M.

    2010-01-01

    Yersinia pestis is a virulent human pathogen and potential biological weapon. Despite a long history of research on this organism, there is no licensed vaccine to protect against pneumonic forms of Y. pestis disease. In the present study, plasmids were constructed to express cholera toxin A2/B chimeric molecules containing the LcrV protective antigen from Y. enterocolitica and Y. pestis. These chimeras were expressed and purified to high yields from the supernatant of transformed E. coli. Wes...

  11. A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

    Science.gov (United States)

    Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

    2015-09-01

    The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde

  12. 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.

  13. 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...

  14. Cholera toxin B suppresses allergic inflammation through induction of secretory IgA.

    Science.gov (United States)

    Smits, H H; Gloudemans, A K; van Nimwegen, M; Willart, M A; Soullié, T; Muskens, F; de Jong, E C; Boon, L; Pilette, C; Johansen, F-E; Hoogsteden, H C; Hammad, H; Lambrecht, B N

    2009-07-01

    In healthy individuals, humoral immune responses to allergens consist of serum IgA and IgG4, whereas cellular immune responses are controlled by regulatory T (Treg) cells. In search of new compounds that might prevent the onset of allergies by stimulating this type of immune response, we have focused on the mucosal adjuvant, cholera toxin B (CTB), as it induces the formation of Treg cells and production of IgA. Here, we have found that CTB suppresses the potential of dendritic cells to prime for Th2 responses to inhaled allergen. When we administered CTB to the airways of naïve and allergic mice, it strongly suppressed the salient features of asthma, such as airway eosinophilia, Th2 cytokine synthesis, and bronchial hyperreactivity. This beneficial effect was only transferable to other mice by transfer of B but not of T lymphocytes. CTB caused a transforming growth factor-beta-dependent rise in antigen-specific IgA in the airway luminal secretions, which was necessary for its preventive and curative effect, as all effects of CTB were abrogated in mice lacking the luminal IgA transporting polymeric Ig receptor. Not only do these findings show a novel therapeutic avenue for allergy, they also help to explain the complex relationship between IgA levels and risk of developing allergy in humans. PMID:19404246

  15. Mutants of Escherichia coli heat-labile enterotoxin and cholera toxin as mucosal adjuvants

    Institute of Scientific and Technical Information of China (English)

    FENG Qiang; CAI Shaoxi; ZOU Quanming

    2003-01-01

    Mucosal vaccination has been getting more and more recognition because of its compliance and low risk of spreading infectious disease by contaminated syringes used in subcutaneous immunization. However, most vaccines are unable to induce immune responses when given mucosally, and require the use of strong adjuvant for effective delivery systems. Heat-labile enterotoxin (LT) and Cholera toxin(CT) are powerful mucosal adjuvants when co-administered with soluble antigens. But high toxicity hampers their use in humans. Thanks to the fine knowledge of the structure-function relationship of LT and CT, many nontoxic or low toxic mutants have been generated, part of them retain high adjuvanticity of mucosal immunization. Among these mutants, LTS63K, LTA72R, LTR192G and CTE29H, CTE112K have been widely investigated. LTS63K and CTE112K are fully non toxic, whereas LTA72R and CTE29H are low toxic, and LTR192G is nontoxic in vitro(it remains the same toxicity as wild type LT in vivo). These mutants are extremely active as mucosal adjuvants when co-administrated with a variety of antigens in different animal models. They will be investigated more widely and deeply in the future. Some of them will be tested soon in human bodies.

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

    Science.gov (United States)

    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

  17. Live Staining and Isolation of Specific Hormone-Producing Cells from Rat Anterior Pituitary by Cytochemistry with Lectins and Cholera Toxin B Subunit

    International Nuclear Information System (INIS)

    Anterior pituitary glands contain five types of hormone-producing cells. Distinguishing and isolating specific types of living cells are essential for studying their function. Although many such attempts have been made, the results have been disappointing. In the present study, we labeled specific types of living hormone-producing cells by using potential differences in sugar chains on the cell surfaces. Cytochemical analysis with lectins and cholera toxin B subunit revealed that PNA, S-WGA, and cholera toxin B subunit recognized sugar chains specific to prolactin cells, ACTH cells, and GH cells, respectively, and that UEA-I recognized most of prolactin cells and GH cells. Next, fluorescence-activated cell sorting was used to isolate GH cells labeled by fluoresceinated cholera toxin B. The purity of the GH cell fraction estimated by immunocytochemistry and quantitative real-time PCR for cell type-specific genes was more than 98%, which was higher than that reported in earlier studies, including those using transgenic animals. We conclude that cytochemistry with lectins and cholera toxin B subunit is a straightforward, acceptable method of isolating specific types of anterior pituitary cells and that the cells isolated by this method can serve as useful materials in the study of anterior pituitary cells

  18. Enhancement of anti-Shigella lipopolysaccharide (LPS) response by addition of the cholera toxin B subunit to oral and intranasal proteosome-Shigella flexneri 2a LPS vaccines.

    OpenAIRE

    Orr, N; Arnon, R; Rubin, G; Cohen, D; Bercovier, H; Lowell, G H

    1994-01-01

    Addition of the cholera toxin B subunit to oral and intranasal proteosome-Shigella flexneri 2a lipopolysaccharide vaccines improved their immunogenicities. Enhancement of anti-O-Shigella immunoglobulin A levels was most evident in lung lavages following oral immunization and in lung and intestinal fluids when suboptimal doses were used with either immunization route.

  19. Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy

    DEFF Research Database (Denmark)

    Kroghsbo, S.; Christensen, Hanne Risager; Frøkiær, Hanne

    2003-01-01

    Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle...... interested in characterizing the individual effects of the parameters in the CT-based model: CT dose, antigen type and dose, and number of immunizations. Methods: BALB/c mice were orally sensitized weekly for 3 or 7 weeks with graded doses of CT and various food antigens (soy-trypsin inhibitor, ovalbumin or...... antibody response depended on the type of antigen and number of immunizations. Conclusions: The critical parameters of the CT-based murine allergy model differentially control the intensity and kinetics of the developing immune response. Adjustment of these parameters could be a key tool for tailoring the...

  20. Analysis of a Cholera Toxin B Subunit (CTB) and Human Mucin 1 (MUC1) Conjugate Protein in a MUC1 Tolerant Mouse Model

    OpenAIRE

    Pinkhasov, Julia; Alvarez, M. Lucrecia; Pathangey, Latha B; Tinder, Teresa L; Mason, Hugh S.; Walmsley, Amanda M.; Gendler, Sandra J.; Mukherjee, Pinku

    2010-01-01

    Since epithelial mucin 1 (MUC1) is associated with several adenocarcinomas at mucosal sites, it is pertinent to test the efficacy of a mucosally targeted vaccine formulation. The B subunit of the Vibrio cholerae cholera toxin (CTB) has great potential to act as a mucosal carrier for subunit vaccines. In the present study we evaluated whether a MUC1 tandem repeat (TR) peptide chemically linked to CTB would break self-antigen tolerance in the transgenic MUC1 tolerant mouse model (MUC1.Tg) throu...

  1. Cholera toxin-induced ADP-ribosylation of a 46 kDa protein is decreased in brains of ethanol-fed mice

    International Nuclear Information System (INIS)

    The acute in vitro effects of ethanol on cerebral cortical adenylate cyclase activity and beta-adrenergic receptor characteristics suggested a site of action of ethanol at Gs, the stimulatory guanine nucleotide binding protein. After chronic ethanol ingestion, the beta-adrenergic receptor appeared to be uncoupled (i.e., the form of the receptor with high affinity for agonist was undetectable), and stimulation of adenylate cyclase activity by isoproterenol or guanine nucleotides was reduced, suggesting an alteration in the properties of Gs. To further characterize this change, cholera and pertussis toxin-mediated 32P-ADP-ribosylation of mouse cortical membranes was assessed in mice that had chronically ingested ethanol in a liquid diet. 32P-labeled proteins were separated by SDS-PAGE and quantitated by autoradiography. There was a selective 30-50% decrease in cholera toxin-induced labeling of 46 kDa protein band in membranes of ethanol-fed mice, with no apparent change in pertussis toxin-induced labeling. The 46 kDa protein has a molecular weight similar to that of the alpha subunit of Gs, suggesting a reduced amount of this protein or a change in its characteristics as a substrate for cholera toxin-induced ADP-ribosylation in cortical membranes of ethanol-fed mice

  2. 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.

  3. Binding of fluorescently labeled cholera toxin subunit B to glycolipids in the human submandibular gland and inhibition of binding by periodate oxidation and by galactose

    DEFF Research Database (Denmark)

    Kirkeby, S

    2016-01-01

    remained unaffected even after increased oxidation. Staining with the subunit was also reduced significantly by adding galactose to the incubation medium. Binding of CTB to cell surfaces apparently requires intact sialic groups on most, but not all, cell surfaces. Oxidation of the sialic acid residues may...... influence the structure of the sialylated GM1 molecules on the cell surface in different ways. It is possible that both the sialic acid residue and the terminal galactose are oxidized. Alternatively, the sialic acid may be resistant to acid hydrolysis in gangliosides in which the sialic acid is attached to...... the internal galactose residue linked to GalNAc, as in the GM1 glycolipid. Inhibition of the GM1 receptor binding to cholera toxin has potential for protection of humans against cholera. Galactose and agents that modify sialic acid inhibit the accessibility of the toxin to the GM1 carbohydrate...

  4. Crystallization of two operator complexes from the Vibrio cholerae HigBA2 toxin-antitoxin module

    DEFF Research Database (Denmark)

    Hadzi, San; Garcia-Pino, Abel; Gerdes, Kenn;

    2015-01-01

    The HigA2 antitoxin and the HigBA2 toxin-antitoxin complex from Vibrio cholerae were crystallized in complex with their operator box. Screening of 22 different DNA duplexes led to two crystal forms of HigA2 complexes and one crystal form of a HigBA2 complex. Crystals of HigA2 in complex with a 17...

  5. Binding of fluorescently labeled cholera toxin subunit B to glycolipids in the human submandibular gland and inhibition of binding by periodate oxidation and by galactose.

    Science.gov (United States)

    Kirkeby, S

    2016-01-01

    FITC-labeled cholera toxin subunit B (CTB) stained the surfaces of cells of mucous acini in the submandibular gland. CTB, also called choleragenoid, binds to the GM1 glycolipid in the cell membrane. The binding in most acini was inhibited by periodic acid oxidation of the sections, while some acini remained unaffected even after increased oxidation. Staining with the subunit was also reduced significantly by adding galactose to the incubation medium. Binding of CTB to cell surfaces apparently requires intact sialic groups on most, but not all, cell surfaces. Oxidation of the sialic acid residues may influence the structure of the sialylated GM1 molecules on the cell surface in different ways. It is possible that both the sialic acid residue and the terminal galactose are oxidized. Alternatively, the sialic acid may be resistant to acid hydrolysis in gangliosides in which the sialic acid is attached to the internal galactose residue linked to GalNAc, as in the GM1 glycolipid. Inhibition of the GM1 receptor binding to cholera toxin has potential for protection of humans against cholera. Galactose and agents that modify sialic acid inhibit the accessibility of the toxin to the GM1 carbohydrate receptor. Human milk contains high levels of sialic acid glycoconjugates that may provide defense mechanisms. PMID:26472148

  6. Measurement of the binding of cholera toxin to GM1 gangliosides on solid supported lipid bilayer vesicles and inhibition by europium (III) chloride.

    Science.gov (United States)

    Williams, Thomas L; Jenkins, A Toby A

    2008-05-21

    In this paper the immobilization of small unilamellar DMPC/GM1 lipid vesicles containing a water-soluble bodipy dye is described. The binding of the complete alphabeta toxin expressed by Vibrio cholerae to the attached vesicles was measured using Surface Plasmon Resonance (SPR) and a value of the dissociation constant K d obtained. Further measurements showed that the interaction of both the alphabeta-toxin and the beta-subunit alone resulted in the permeation of the lipid membrane, with release of a fluorophore contained within the vesicle being measured by combined SPR and Surface Plasmon enhanced Fluorescence Spectroscopy (SPFS). The leakage of dye through the membrane, measured by following the change in fluorescence, was fitted to a simple diffusion model. Finally, SPFS measurements of the effect of europium(III) chloride (EuCl 3) showed that cholera toxin binding and subsequent membrane permeation could be blocked by 1 micromol dm (-3) europium chloride. In view of the low oral toxicity of europium chloride, we speculate on the potential pharmaceutical applications of this molecule in the treatment of cholera infection. PMID:18412339

  7. 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; Immerdal, Lissi; Niels-Christiansen, Lise-Lotte; Danielsen, E Michael

    2005-01-01

    microvilli 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...

  8. Influence of tunicamycin, sialidase, and cholera toxin on gangliosides and T-lymphocyte responses to interleukin 2

    International Nuclear Information System (INIS)

    The authors have shown that gangliosides inhibit interleukin 2 (IL 2)-dependent proliferation of murine T cells. Tunicamycin (TM), sialidase, and cholera toxin-β subunit (β-CT) are known modulators of cell surface glycoconjugates. To test the possible role of endogenous gangliosides in T cell responses to IL-2, the effect of these agents on ganglioside expression and cell proliferation was studied. Gangliosides were labelled for 24 hrs with 3H-glucosamine/galactose in the presence of IL-2 and purified sialidase, TM or β-CT. Gangliosides were isolated and the species separated by TLC. Alternatively, proliferation was assayed by 3H-thymidine uptake after 48 hrs culture. TM treatment at a concentration (10 μg/ml) that completely inhibited proliferation resulted in a 86% reduction of incorporation of saccharide precursors into gangliosides compared to a 50% reduction into proteins. Sialidase treatment (0.1 IU/ml) resulted in a 70% inhibition of proliferation and 30% reduction of radiolabel into gangliosides, of which 3 species were specifically reduced. β-CT, which binds to GM1 and to a lesser extent GD/sub 1a/, caused a 50% reduction in proliferation response at 35 units/ml. The results support the hypothesis that gangliosides are involved in IL-2-dependent proliferation

  9. Molecular cloning, characterization, and expression of human ADP-ribosylation factors: Two guanine nucleotide-dependent activators of cholera toxin

    International Nuclear Information System (INIS)

    ADP-ribosylation factors (ARFs) are small guanine nucleotide-binding proteins that enhance the enzymatic activities of cholera toxin. Two ARF cDNAs, ARF1 and ARF3, were cloned from a human cerebellum library. Based on deduced amino acid sequences and patterns of hybridization of cDNA and oligonucleotide probes with mammalian brain poly(A)+ RNA, human ARF1 is the homologue of bovine ARF1. Human ARF3, which differs from bovine ARF1 and bovine ARF2, appears to represent a newly identified third type of ARF. Hybridization patterns of human ARF cDNA and clone-specific oligonucleotides with poly(A)+ RNA are consistent with the presence of at least two, and perhaps four, separate ARF messages in human brain. In vitro translation of ARF1, ARF2, and ARF3 produced proteins that behaved, by SDS/PAGE, similar to a purified soluble brain ARF. Deduced amino acid sequences of human ARF1 and ARF3 contain regions, similar to those in other G proteins, that are believed to be involved in GTP binding and hydrolysis. ARFS also exhibit a modest degree of homology with a bovine phospholipase C. The observations reported here support the conclusion that the ARFs are members of a multigene family of small guanine nucleotide-binding proteins. Definition of the regulation of ARF mRNAs and of function(s) of recombinant ARF proteins will aid in the elucidation of the physiologic role(s) of ARFs

  10. Role of the RS1 sequence of the cholera vibrio in amplification of the segment of plasmid DNA carrying the gene of resistance to tetracycline and the genes of cholera toxin

    International Nuclear Information System (INIS)

    The hybrid plasmid pCO107, representing cointegrate 14(2)-5(2) of two plasmids, an F-derivative (pOX38) and a PBR322-derivative (pCT105) with an RS1 sequence of the cholera vibrio cloned in its makeup, contains two copes of RS1 at the sites of union of the two plasmids. Using a tetracycline resistance marker (TcR) of the plasmid pCT105, clones were isolated which have an elevated level of resistance to tetracycline (an increase of from 4- to 30-fold). Using restriction analysis and the Southern blot method of hybridization it was shown that the increase in the level of resistance of tetracycline is associated with the amplification of pCT105 portion of the cointegrate, and that the process of amplification is governed by the presence of direct repeats of the RS1 sequence at its ends. The increase in the number of copies of the pCT105 segment, which contains in its composition the genes of cholera toxin (vct), is accompanied by an increase in toxin production

  11. Induction of indoleamine 2, 3-dioxygenase in human dendritic cells by a cholera toxin B subunit-proinsulin vaccine.

    Directory of Open Access Journals (Sweden)

    Jacques C Mbongue

    Full Text Available Dendritic cells (DC interact with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this study, immature human dendritic cells (iDC were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS. Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1. Increased biosynthesis of the immunosuppressive enzyme was detected in DCs inoculated with the CTB-INS fusion protein but not in DCs inoculated with proinsulin, CTB, or an unlinked combination of the two proteins. Immunoblot and PCR analyses of vaccine treated DCs detected IDO1mRNA by 3 hours and IDO1 protein synthesis by 6 hours after vaccine inoculation. Determination of IDO1 activity in vaccinated DCs by measurement of tryptophan degradation products (kynurenines showed increased tryptophan cleavage into N-formyl kynurenine. Vaccination did not interfere with monocytes differentiation into DC, suggesting the vaccine can function safely in the human immune system. Treatment of vaccinated DCs with pharmacological NF-κB inhibitors ACHP or DHMEQ significantly inhibited IDO1 biosynthesis, suggesting a role for NF-κB signaling in vaccine up-regulation of dendritic cell IDO1. Heat map analysis of the proteomic data revealed an overall down-regulation of vaccinated DC functions, suggesting vaccine suppression of DC maturation. Together, our experimental data indicate that CTB-INS vaccine induction of IDO1 biosynthesis in human DCs may result in the inhibition of DC maturation generating a durable state of immunological tolerance. Understanding how CTB-INS modulates IDO1 activity in human DCs will facilitate vaccine efficacy and safety, moving this immunosuppressive strategy closer to clinical applications for prevention

  12. Selection of cholera toxin specific IgNAR single-domain antibodies from a naïve shark library.

    Science.gov (United States)

    Liu, Jinny L; Anderson, George P; Delehanty, James B; Baumann, Richard; Hayhurst, Andrew; Goldman, Ellen R

    2007-03-01

    Shark immunoglobulin new antigen receptor (IgNAR, also referred to as NAR) variable domains (Vs) are single-domain antibody (sdAb) fragments containing only two hypervariable loop structures forming 3D topologies for a wide range of antigen recognition and binding. Their small size ( approximately 12kDa) and high solubility, thermostability and binding specificity make IgNARs an exceptional alternative source of engineered antibodies for sensor applications. Here, two new shark NAR V display libraries containing >10(7) unique clones from non-immunized (naïve) adult spiny dogfish (Squalus acanthias) and smooth dogfish (Mustelus canis) sharks were constructed. The most conserved consensus sequences derived from random clone sequence were compared with published nurse shark (Ginglymostoma cirratum) sequences. Cholera toxin (CT) was chosen for panning one of the naïve display libraries due to its severe pathogenicity and commercial availability. Three very similar CT binders were selected and purified soluble monomeric anti-CT sdAbs were characterized using Luminex(100) and traditional ELISA assays. These novel anti-CT sdAbs selected from our newly constructed shark NAR V sdAb library specifically bound to soluble antigen, without cross reacting with other irrelevant antigens. They also showed superior heat stability, exhibiting slow loss of activity over the course of one hour at high temperature (95 degrees C), while conventional antibodies lost all activity in the first 5-10min. The successful isolation of target specific sdAbs from one of our non-biased NAR libraries, demonstrate their ability to provide binders against an unacquainted antigen of interest. PMID:17007931

  13. Identification of a TcpC-TcpQ Outer Membrane Complex Involved in the Biogenesis of the Toxin-Coregulated Pilus of Vibrio cholerae

    OpenAIRE

    Bose, Niranjan; Taylor, Ronald K.

    2005-01-01

    The toxin-coregulated pilus (TCP) of Vibrio cholerae and the soluble TcpF protein that is secreted via the TCP biogenesis apparatus are essential for intestinal colonization. The TCP biogenesis apparatus is composed of at least nine proteins but is largely uncharacterized. TcpC is an outer membrane lipoprotein required for TCP biogenesis that is a member of the secretin protein superfamily. In the present study, analysis of TcpC in a series of strains deficient in each of the TCP biogenesis p...

  14. 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...

  15. Evidence for TLR4 and FcRγ-CARD9 activation by cholera toxin B subunit and its direct bindings to TREM2 and LMIR5 receptors.

    Science.gov (United States)

    Phongsisay, Vongsavanh; Iizasa, Ei'ichi; Hara, Hiromitsu; Yoshida, Hiroki

    2015-08-01

    Cholera toxin (CTX) is a virulent factor of Vibrio cholerae that causes life-threatening diarrheal disease. Its non-toxic subunit CTB has been extensively studied for vaccine delivery. In immune cells, CTB induces a number of signaling molecules related to cellular activation and cytokine production. The mechanisms by which CTB exerts its immunological effects are not understood. We report here the immunological targets of CTB. The unexpected finding that GM1 ganglioside inhibited NF-κB activation in human monocytes stimulated with CTX and agonists of Toll-like receptors (TLR) suggests the possibility of CTX-TLR interaction. Indeed, CTX-induced IL-6 production was substantially reduced in MyD88(-/-) or TLR4(-/-) macrophages. Ectopic expression of TLR4 was required for CTX-induced NF-κB activation in HEK 293 cells. Furthermore, the inflammatory capacity of CTB was lost in the absence of TLR4, adaptor protein FcRγ, or its downstream signaling molecule CARD9. Attempts have been made to identify CTB-binding targets from various C-type lectin and immunoglobulin-like receptors. CTB targeted not only GM1 and TLR4 but also TREM2 and LMIR5/CD300b. CTB-TREM2 interaction initiated signal transduction through adaptor protein DAP12. The binding of CTB inhibited LMIR5 activation induced by its endogenous ligand 3-O-sulfo-β-d-galactosylceramide C24:1. In summary, CTB targets TLR4, FcRγ-CARD9, TREM2, and LMIR5. These findings provide new insights into the immunobiology of cholera toxin. PMID:26021803

  16. Toxins

    Science.gov (United States)

    Toxins are substances created by plants and animals that are poisonous to humans. Toxins also include some medicines that are helpful in small doses, but poisonous in large amounts. Most toxins that ...

  17. 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,...

  18. Analysis of a Cholera Toxin B Subunit (CTB) and Human Mucin 1 (MUC1) Conjugate Protein in a MUC1 Tolerant Mouse Model

    Science.gov (United States)

    Pinkhasov, Julia; Alvarez, M. Lucrecia; Pathangey, Latha B.; Tinder, Teresa L.; Mason, Hugh S.; Walmsley, Amanda M.; Gendler, Sandra J.; Mukherjee, Pinku

    2011-01-01

    Since epithelial mucin 1 (MUC1) is associated with several adenocarcinomas at mucosal sites, it is pertinent to test the efficacy of a mucosally targeted vaccine formulation. The B subunit of the Vibrio cholerae cholera toxin (CTB) has great potential to act as a mucosal carrier for subunit vaccines. In the present study we evaluated whether a MUC1 tandem repeat (TR) peptide chemically linked to CTB would break self-antigen tolerance in the transgenic MUC1 tolerant mouse model (MUC1.Tg) through oral or parenteral immunizations. We report that oral immunization with the CTB-MUC1 conjugate along with mucosal adjuvant, unmethylated CpG oligodeoxynucleotide (ODN) and interleukin-12 (IL-12), did not break self-antigen tolerance in MUC1.Tg mice, but induced a strong humoral response in wild-type C57BL/6 mice. However, self-antigen tolerance in the MUC1.Tg mouse model was broken after parenteral immunizations with different doses of the CTB-MUC1 conjugate protein and with the adjuvant CpG ODN co-delivered with CTB-MUC1. Importantly, mice immunized systemically with CpG ODN alone and with CTB-MUC1 exhibited decreased tumor burden when challenged with a mammary gland tumor cell line that expresses human MUC1. PMID:20824430

  19. Analysis of a cholera toxin B subunit (CTB) and human mucin 1 (MUC1) conjugate protein in a MUC1-tolerant mouse model.

    Science.gov (United States)

    Pinkhasov, Julia; Alvarez, M Lucrecia; Pathangey, Latha B; Tinder, Teresa L; Mason, Hugh S; Walmsley, Amanda M; Gendler, Sandra J; Mukherjee, Pinku

    2010-12-01

    Since epithelial mucin 1 (MUC1) is associated with several adenocarcinomas at the mucosal sites, it is pertinent to test the efficacy of a mucosally targeted vaccine formulation. The B subunit of the Vibrio cholerae cholera toxin (CTB) has great potential to act as a mucosal carrier for subunit vaccines. In the present study we evaluated whether a MUC1 tandem repeat (TR) peptide chemically linked to CTB would break self-antigen tolerance in the transgenic MUC1-tolerant mouse model (MUC1.Tg) through oral or parenteral immunizations. We report that oral immunization with the CTB-MUC1 conjugate along with mucosal adjuvant, unmethylated CpG oligodeoxynucleotide (ODN) and interleukin-12 (IL-12) did not break self-antigen tolerance in MUC1.Tg mice, but induced a strong humoral response in wild-type C57BL/6 mice. However, self-antigen tolerance in the MUC1.Tg mouse model was broken after parenteral immunizations with different doses of the CTB-MUC1 conjugate protein and with the adjuvant CpG ODN co-delivered with CTB-MUC1. Importantly, mice immunized systemically with CpG ODN alone and with CTB-MUC1 exhibited decreased tumor burden when challenged with a mammary gland tumor cell line that expresses human MUC1. PMID:20824430

  20. 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.

  1. A Mutational Analysis of Residues in Cholera Toxin A1 Necessary for Interaction with Its Substrate, the Stimulatory G Protein Gsα

    Directory of Open Access Journals (Sweden)

    Michael G. Jobling

    2015-03-01

    Full Text Available Pathogenesis of cholera diarrhea requires cholera toxin (CT-mediated adenosine diphosphate (ADP-ribosylation of stimulatory G protein (Gsα in enterocytes. CT is an AB5 toxin with an inactive CTA1 domain linked via CTA2 to a pentameric receptor-binding B subunit. Allosterically activated CTA1 fragment in complex with NAD+ and GTP-bound ADP-ribosylation factor 6 (ARF6-GTP differs conformationally from the CTA1 domain in holotoxin. A surface-exposed knob and a short α-helix (formed, respectively, by rearranging “active-site” and “activation” loops in inactive CTA1 and an ADP ribosylating turn-turn (ARTT motif, all located near the CTA1 catalytic site, were evaluated for possible roles in recognizing Gsα. CT variants with one, two or three alanine substitutions at surface-exposed residues within these CTA1 motifs were tested for assembly into holotoxin and ADP-ribosylating activity against Gsα and diethylamino-(benzylidineamino-guanidine (DEABAG, a small substrate predicted to fit into the CTA1 active site. Variants with single alanine substitutions at H55, R67, L71, S78, or D109 had nearly wild-type activity with DEABAG but significantly decreased activity with Gsα, suggesting that the corresponding residues in native CTA1 participate in recognizing Gsα. As several variants with multiple substitutions at these positions retained partial activity against Gsα, other residues in CTA1 likely also participate in recognizing Gsα.

  2. A Cholera Conjugate Vaccine Containing O-specific Polysaccharide (OSP of V. cholerae O1 Inaba and Recombinant Fragment of Tetanus Toxin Heavy Chain (OSP:rTTHc Induces Serum, Memory and Lamina Proprial Responses against OSP and Is Protective in Mice.

    Directory of Open Access Journals (Sweden)

    Md Abu Sayeed

    Full Text Available Vibrio cholerae is the cause of cholera, a severe watery diarrhea. Protection against cholera is serogroup specific. Serogroup specificity is defined by the O-specific polysaccharide (OSP component of lipopolysaccharide (LPS.Here we describe a conjugate vaccine for cholera prepared via squaric acid chemistry from the OSP of V. cholerae O1 Inaba strain PIC018 and a recombinant heavy chain fragment of tetanus toxin (OSP:rTTHc. We assessed a range of vaccine doses based on the OSP content of the vaccine (10-50 μg, vaccine compositions varying by molar loading ratio of OSP to rTTHc (3:1, 5:1, 10:1, effect of an adjuvant, and route of immunization.Immunized mice developed prominent anti-OSP and anti-TT serum IgG responses, as well as vibriocidal antibody and memory B cell responses following intramuscular or intradermal vaccination. Mice did not develop anti-squarate responses. Intestinal lamina proprial IgA responses targeting OSP occurred following intradermal vaccination. In general, we found comparable immune responses in mice immunized with these variations, although memory B cell and vibriocidal responses were blunted in mice receiving the highest dose of vaccine (50 μg. We found no appreciable change in immune responses when the conjugate vaccine was administered in the presence or absence of immunoadjuvant alum. Administration of OSP:rTTHc resulted in 55% protective efficacy in a mouse survival cholera challenge model.We report development of an Inaba OSP:rTTHc conjugate vaccine that induces memory responses and protection against cholera in mice. Development of an effective cholera conjugate vaccine that induces high level and long-term immune responses against OSP would be beneficial, especially in young children who respond poorly to polysaccharide antigens.

  3. 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 ...

  4. Intranasal Immunization with Influenza Virus-Like Particles Containing Membrane-Anchored Cholera Toxin B or Ricin Toxin B Enhances Adaptive Immune Responses and Protection against an Antigenically Distinct Virus

    Science.gov (United States)

    Ji, Xianliang; Ren, Zhiguang; Xu, Na; Meng, Lingnan; Yu, Zhijun; Feng, Na; Sang, Xiaoyu; Li, Shengnan; Li, Yuanguo; Wang, Tiecheng; Zhao, Yongkun; Wang, Hualei; Zheng, Xuexing; Jin, Hongli; Li, Nan; Yang, Songtao; Cao, Jinshan; Liu, Wensen; Gao, Yuwei; Xia, Xianzhu

    2016-01-01

    Vaccination is the most effective means to prevent influenza virus infection, although current approaches are associated with suboptimal efficacy. Here, we generated virus-like particles (VLPs) composed of the hemagglutinin (HA), neuraminidase (NA) and matrix protein (M1) of A/Changchun/01/2009 (H1N1) with or without either membrane-anchored cholera toxin B (CTB) or ricin toxin B (RTB) as molecular adjuvants. The intranasal immunization of mice with VLPs containing membrane-anchored CTB or RTB elicited stronger humoral and cellular immune responses when compared to mice immunized with VLPs alone. Administration of VLPs containing CTB or RTB significantly enhanced virus-specific systemic and mucosal antibody responses, hemagglutination inhibiting antibody titers, virus neutralizing antibody titers, and the frequency of virus-specific IFN-γ and IL-4 secreting splenocytes. VLPs with and without CTB or RTB conferred complete protection against lethal challenge with a mouse-adapted homologous virus. When challenged with an antigenically distinct H1N1 virus, all mice immunized with VLPs containing CTB or RTB survived whereas mice immunized with VLPs alone showed only partial protection (80% survival). Our results suggest that membrane-anchored CTB and RTB possess strong adjuvant properties when incorporated into an intranasally-delivered influenza VLP vaccine. Chimeric influenza VLPs containing CTB or RTB may represent promising vaccine candidates for improved immunological protection against homologous and antigenically distinct influenza viruses. PMID:27110810

  5. Cholera toxin B subunit-five-stranded α-helical coiled-coil fusion protein: "five-to-five" molecular chimera displays robust physicochemical stability.

    Science.gov (United States)

    Arakawa, Takeshi; Harakuni, Tetsuya

    2014-09-01

    To create a physicochemically stable cholera toxin (CT) B subunit (CTB), it was fused to the five-stranded α-helical coiled-coil domain of cartilage oligomeric matrix protein (COMP). The chimeric fusion protein (CTB-COMP) was expressed in Pichia pastoris, predominantly as a pentamer, and retained its affinity for the monosialoganglioside GM1, a natural receptor of CT. The fusion protein displayed thermostability, tolerating the boiling temperature of water for 10min, whereas unfused CTB readily dissociated to its monomers and lost its affinity for GM1. The fusion protein also displayed resistance to strong acid at pHs as low as 0.1, and to the protein denaturant sodium dodecyl sulfate at concentrations up to 10%. Intranasal administration of the fusion protein to mice induced anti-B subunit serum IgG, even after the protein was boiled, whereas unfused CTB showed no thermostable mucosal immunogenicity. This study demonstrates that CTB fused to a pentameric α-helical coiled coil has a novel physicochemical phenotype, which may provide important insight into the molecular design of enterotoxin-B-subunit-based vaccines and vaccine delivery molecules. PMID:25045819

  6. NKp46+ Innate Lymphoid Cells Dampen Vaginal CD8 T Cell Responses following Local Immunization with a Cholera Toxin-Based Vaccine.

    Directory of Open Access Journals (Sweden)

    Carmelo Luci

    Full Text Available Innate and adaptive immune cells work in concert to generate efficient protection at mucosal surface. Vaginal mucosa is an epithelial tissue that contains innate and adaptive immune effector cells. Our previous studies demonstrated that vaginal administration of Cholera toxin -based vaccines generate antigen-specific CD8 T cells through the stimulation of local dendritic cells (DC. Innate lymphoid cells (ILC are a group of lymphocytes localized in epithelial tissues that have important immune functions against pathogens and in tissue homeostasis. Their contribution to vaccine-induced mucosal T cell responses is an important issue for the design of protective vaccines. We report here that the vaginal mucosa contains a heterogeneous population of NKp46+ ILC that includes conventional NK cells and ILC1-like cells. We show that vaginal NKp46+ ILC dampen vaccine-induced CD8 T cell responses generated after local immunization. Indeed, in vivo depletion of NKp46+ ILC with anti-NK1.1 antibody or NKG2D blockade increases the magnitude of vaginal OVA-specific CD8 T cells. Furthermore, such treatments also increase the number of DC in the vagina. NKG2D ligands being expressed by vaginal DC but not by CD8 T cells, these results support that NKp46+ ILC limit mucosal CD8 T cell responses indirectly through the NKG2D-dependent elimination of vaginal DC. Our data reveal an unappreciated role of NKp46+ ILC in the regulation of mucosal CD8 T cell responses.

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

    Science.gov (United States)

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

    2014-06-01

    Vibrio cholerae is the causative agent of the acute diarrheal disease of cholera. Innate immune responses to V. cholerae are not a major cause of cholera pathology, which is characterized by severe, watery diarrhea induced by the action of cholera toxin. Innate responses may, however, contribute to resolution of infection and must be required to initiate adaptive responses after natural infection and oral vaccination. Here we investigated whether a well-established infant mouse model of cholera can be used to observe an innate immune response. We also used a vaccination model in which immunized dams protect their pups from infection through breast milk antibodies to investigate innate immune responses after V. cholerae infection for pups suckled by an immune dam. At the peak of infection, we observed neutrophil recruitment accompanied by induction of KC, macrophage inflammatory protein 2 (MIP-2), NOS-2, interleukin-6 (IL-6), and IL-17a. Pups suckled by an immunized dam did not mount this response. Accessory toxins RtxA and HlyA played no discernible role in neutrophil recruitment in a wild-type background. The innate response to V. cholerae deleted for cholera toxin-encoding phage (CTX) and part of rtxA was significantly reduced, suggesting a role for CTX-carried genes or for RtxA in the absence of cholera toxin (CTX). Two extracellular V. cholerae DNases were not required for neutrophil recruitment, but DNase-deficient V. cholerae caused more clouds of DNA in the intestinal lumen, which appeared to be neutrophil extracellular traps (NETs), suggesting that V. cholerae DNases combat NETs. Thus, the infant mouse model has hitherto unrecognized utility for interrogating innate responses to V. cholerae infection. PMID:24686062

  8. Binding Cooperativity Matters: A GM1-Like Ganglioside-Cholera Toxin B Subunit Binding Study Using a Nanocube-Based Lipid Bilayer Array.

    Science.gov (United States)

    Worstell, Nolan C; Krishnan, Pratik; Weatherston, Joshua D; Wu, Hung-Jen

    2016-01-01

    Protein-glycan recognition is often mediated by multivalent binding. These multivalent bindings can be further complicated by cooperative interactions between glycans and individual glycan binding subunits. Here we have demonstrated a nanocube-based lipid bilayer array capable of quantitatively elucidating binding dissociation constants, maximum binding capacity, and binding cooperativity in a high-throughput format. Taking cholera toxin B subunit (CTB) as a model cooperativity system, we studied both GM1 and GM1-like gangliosides binding to CTB. We confirmed the previously observed CTB-GM1 positive cooperativity. Surprisingly, we demonstrated fucosyl-GM1 has approximately 7 times higher CTB binding capacity than GM1. In order to explain this phenomenon, we hypothesized that the reduced binding cooperativity of fucosyl-GM1 caused the increased binding capacity. This was unintuitive, as GM1 exhibited higher binding avidity (16 times lower dissociation constant). We confirmed the hypothesis using a theoretical stepwise binding model of CTB. Moreover, by taking a mixture of fucosyl-GM1 and GM2, we observed the mild binding avidity fucosyl-GM1 activated GM2 receptors enhancing the binding capacity of the lipid bilayer surface. This was unexpected as GM2 receptors have negligible binding avidity in pure GM2 bilayers. These unexpected discoveries demonstrate the importance of binding cooperativity in multivalent binding mechanisms. Thus, quantitative analysis of multivalent protein-glycan interactions in heterogeneous glycan systems is of critical importance. Our user-friendly, robust, and high-throughput nanocube-based lipid bilayer array offers an attractive method for dissecting these complex mechanisms. PMID:27070150

  9. Expression of recombinant T-cell epitopes of major Japanese cedar pollen allergens fused with cholera toxin B subunit in Escherichia coli.

    Science.gov (United States)

    Hoang, Vinh Van; Zou, Yanshuang; Kurata, Kentaro; Enomoto, Keiichi

    2015-05-01

    Peptides containing T-cell epitopes from allergens, which are not reactive to allergen-specific IgE, are appropriate candidates as antigens for specific immunotherapy against allergies. To develop a vaccine that can be used in practical application to prevent and treat Japanese cedar pollen allergy, four major T-cell epitopes from the Cry j 1 antigen and six from the Cry j 2 antigen were selected to design cry j 1 epi and cry j 2 epi, DNA constructs encoding artificial polypeptides of the selected epitopes. To apply cholera toxin B subunit (CTB) as an adjuvant, cry j 1 epi and cry j 2 epi were linked and then fused to the CTB gene in tandem to construct a fusion gene, ctb-linker-cry j 1 epi- cry j 2 epi-flag. The fusion gene was introduced into a pET-28a(+) vector and expressed in Escherichia coli BL21(DE3). The expressed recombinant protein was purified by a His-tag affinity column and confirmed by western blot analysis using anti-CTB and anti-FLAG antibodies. The purified recombinant protein also proved to be antigenic against anti-Cry j 1 and anti-Cry j 2 antibodies. Expression of the recombinant protein induced with 1mM IPTG reached a maximum in 3-5h, and recovery of the affinity-purified recombinant protein was approximately 120mg/L of culture medium. The present study indicates that production of sufficient amounts of recombinant protein with antigenic epitopes may be possible by recombinant techniques using E. coli or other bacterial strains for protein expression. PMID:25665505

  10. Inhibition of virulence potential of Vibrio cholerae by natural compounds

    OpenAIRE

    Yamasaki, Shinji; Asakura, Masahiro; Neogi, Sucharit Basu; Hinenoya, Atsushi; Iwaoka, Emiko; Aoki, Shunji

    2011-01-01

    The rise in multi-drug resistant Vibrio cholerae strains is a big problem in treatment of patients suffering from severe cholera. Only a few studies have evaluated the potential of natural compounds against V. cholerae. Extracts from plants like ‘neem’, ‘guazuma’, ‘daio’, apple, hop, green tea and elephant garlic have been shown to inhibit bacterial growth or the secreted cholera toxin (CT). However, inhibiting bacterial growth like common antimicrobial agents may also impose selective pressu...

  11. Follicle-stimulating hormone receptor-mediated uptake of 45Ca2+ by cultured rat Sertoli cells does not require activation of cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding proteins or adenylate cyclase

    International Nuclear Information System (INIS)

    We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) consistently stimulated basal levels of androstenedione conversion to estradiol but had no effect on basal levels of 45Ca2+ uptake. Similarly, CT had no effect on FSH-induced 45Ca2+ uptake, but potentiated FSH-stimulated estradiol synthesis. PT (10 ng/ml) augmented basal and FSH-stimulated estradiol secretion without affecting 45Ca2+ influx. The adenosine analog N6-phenylisopropyladenosine, which binds to Gi-coupled adenosine receptors on Sertoli cells, inhibited FSH-stimulated androgen conversion to estradiol in a dose-related (1-1000 nM) manner, but FSH-stimulated 45Ca2+ influx remained unchanged. Our results show that in contrast to FSH-stimulated estradiol synthesis, the flux of 45Ca2+ into Sertoli cells in response to FSH is not mediated either directly or indirectly by CT- or PT-sensitive G protein, nor does it require activation of AC. Our data further suggest that the FSH receptor itself may function as a calcium channel

  12. Comparison of Intranasal Outer Membrane Vesicles with Cholera Toxin and Injected MF59C.1 as Adjuvants for Malaria Transmission Blocking Antigens AnAPN1 and Pfs48/45

    Science.gov (United States)

    Pritsch, Michael; Ben-Khaled, Najib; Chaloupka, Michael; Kobold, Sebastian; Berens-Riha, Nicole; Peter, Annabell; Liegl, Gabriele; Schubert, Sören; Hoelscher, Michael; Löscher, Thomas; Wieser, Andreas

    2016-01-01

    Purified protein vaccines often require adjuvants for efficient stimulation of immune responses. There is no licensed mucosal adjuvant on the market to adequately boost the immune response to purified antigens for intranasal applications in humans. Bacterial outer membrane vesicles (OMV) are attractive candidates potentially combining antigenic and adjuvant properties in one substance. To more precisely characterize the potential of Escherichia coli OMV for intranasal vaccination with heterologous antigens, immune responses for AnAPN1 and Pfs48/45 as well as ovalbumin as a reference antigen were assessed in mice. The intranasal adjuvant cholera toxin (CT) and parenteral adjuvant MF59C.1 were used in comparison. Vaccinations were administered intranasally or subcutaneously. Antibodies (total IgG and IgM as well as subclasses IgG1, IgG2a, IgG2b, and IgG3) were measured by ELISA. T cell responses (cytotoxic T cells, Th1, Th17, and regulatory T cells) were determined by flow cytometry. When OMV were used as adjuvant for intranasal immunization, antibody and cellular responses against all three antigens could be induced, comparable to cholera toxin and MF59C.1. Antigen-specific IgG titres above 1 : 105 could be detected in all groups. This study provides the rationale for further development of OMV as a vaccination strategy in malaria and other diseases.

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

    Directory of Open Access Journals (Sweden)

    Salah Shanan

    2016-04-01

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

  14. 霍乱毒素黏膜免疫佐剂作用研究进展%Cholera toxin as an adjuvant for mucosal immunization

    Institute of Scientific and Technical Information of China (English)

    陈晓月; 金宁一; 邹伟; 海洋

    2007-01-01

    @@ 霍乱(cholera)是由霍乱弧菌(vibrio cholerae)引起的急性传染病,属三大国际检疫传染病之一,也是我国法定管理的甲类传染病.其病理变化主要由霍乱弧菌的肠毒素所致,临床表现为不同程度的腹泻、呕吐、失水,少数患者出现肌肉痉挛、代谢性酸中毒、循环衰竭等.

  15. Low-dose oral tolerance due to antigen in the diet suppresses differentially the cholera toxin-adjuvantized IgE, IgA and IgG response

    DEFF Research Database (Denmark)

    Christensen, Hanne Risager; Kjær, Tanja; Frøkiær, Hanne

    2003-01-01

    Background: Cholera toxin (CT) is used as a mucosal adjuvant amongst other applications for studying food allergy because oral administration of antigen with CT induces an antigen-specific type 2 response, including IgE and IgA production. Priorly established oral tolerance due to antigen in the......G response. The results revealed that low-dose oral tolerance includes the mucosal IgA response and that CT, albeit mediating an antigen-specific response, does not fully abrogate priorly established oral tolerance....... diet may radically impact on the CT-adjuvantized immune response. The present study served to evaluate the effect of priorly established low-dose oral tolerance on the CT-adjuvantized immune response towards a food antigen. Methods: Mice fed a diet containing microgram levels of the soy protein Kunitz...

  16. Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

    Directory of Open Access Journals (Sweden)

    T. Petr

    2010-05-01

    Full Text Available A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde, which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at -20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion, and removal of cholesterol, which can act as a hydrophobic blocking barrier.

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

    Directory of Open Access Journals (Sweden)

    StefanPukatzki

    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.

  18. Drinking cholera

    DEFF Research Database (Denmark)

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

    2015-01-01

    . Methods: Hundred participants took part in a taste-testing experiment of water with varying levelsof salinity. Salinity measurements were taken of both drinking and non-drinking water sources.Informal group discussions were conducted to gain an in-depth understanding of water sources andwater uses...... beconducive to V. cholerae survival. Furthermore, salinity levels of participant’s drinking water sourceswere all well below the levels required for optimal survival of V. cholerae. Respondents explainedthat they preferred less salty and more aesthetically pleasing drinking water. Conclusion: Theoretically, V...

  19. 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

  20. 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

  1. Merozoite surface protein-1 of Plasmodium yoelii fused via an oligosaccharide moiety of cholera toxin B subunit glycoprotein expressed in yeast induced protective immunity against lethal malaria infection in mice.

    Science.gov (United States)

    Miyata, Takeshi; Harakuni, Tetsuya; Taira, Toki; Matsuzaki, Goro; Arakawa, Takeshi

    2012-01-20

    Methylotrophic yeast (Pichia pastoris) secreted cholera toxin B subunit (CTB) predominantly as a biologically active pentamer (PpCTB) with identical ganglioside binding affinity profiles to that of choleragenoid. Unlike choleragenoid, however, the PpCTB did not induce a footpad edema response in mice. Of the two potential glycosylation sites (NIT(4-6) and NKT(90-92)) for this protein, a N-linked oligosaccharide was identified at Asn4. The oligosaccharide, presumed to extend from the lateral circumference of the CTB pentamer ring structure, was exploited as a site-specific anchoring scaffold for the C-terminal 19-kDa merozoite surface protein-1 (MSP1-19) of the rodent malaria parasite, Plasmodium yoelii. Conjugation of MSP1-19 to PpCTB via its oligosaccharide moiety induced higher protective efficacy against lethal parasite infection than conjugation directly to the PpCTB protein body in both intranasal and subcutaneous immunization regimes. Such increased protection was potentially due to the higher antigen loading capacity of CTB achieved when the antigen was linked to the extended branches of the oligosaccharide. This might have allowed the antigen to reside in more spacious molecular environment with less steric hindrance between the constituent molecules of the fusion complex. PMID:22119928

  2. Expression of cholera toxin B-lumbrokinase fusion protein in Pichia pastoris--the use of transmucosal carriers in the delivery of therapeutic proteins to protect rats against thrombosis.

    Science.gov (United States)

    Chunfeng, Guan; Xiaozhou, Li; Gang, Wang; Jing, Ji; Chao, Jin; Josine, Tchouopou Lontchi

    2013-01-01

    Cholera toxin B-subunit (CTB) has been widely used to facilitate antigen delivery by serving as an effective mucosal carrier molecule for the induction of oral tolerance. However, whether CTB can be used as a transmucosal carrier in the delivery of not only vaccines but also therapeutic proteins has not been widely studied. Thus, we investigate here the concept of receptor-mediated oral delivery of lumbrokinase (LK) proteins which is an important fibrinolytic enzyme derived from earthworm. CTB and LK, separated by a furin cleavage site, was expressed via Pichia pastoris. The activity and proper folding of recombinant protein in yeast were confirmed by Western blot analysis, fibrin plate assays, and G(M1)-ganglioside ELISA. Following oral administration of recombinant protein, the thrombosis model of rats and mice revealed that the oral treatment of rCTB-LK has a more significant anti-thrombotic effect on animals compared with rLK. It is possible to conclude that CTB can successfully enhance its fusion protein LK to be absorbed. The use of CTB as a transmucosal carrier in the delivery of not only vaccines but also therapeutic proteins was supported. PMID:23269637

  3. Nucleotide sequence homology between the heat-labile enterotoxin gene of Escherichia coli and Vibrio cholerae deoxyribonucleic acid.

    OpenAIRE

    Moseley, S L; Falkow, S

    1980-01-01

    Isolated deoxyribonucleic acid fragments encoding the heat-labile enterotoxin of Escherichia coli were used to probe for homologous sequences in restricted whole-cell deoxyribonucleic acid from Vibrio cholerae. Significant sequence homology between the heat-labile enterotoxin gene and V. cholerae deoxyribonucleic acid was demonstrated, and apparent differences were observed in the organization of the cholera toxin gene among different strains of V. cholerae.

  4. 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

  5. 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

  6. 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

  7. High-Resolution Crystal Structures Elucidate the Molecular Basis of Cholera Blood Group Dependence

    Science.gov (United States)

    Heggelund, Julie Elisabeth; Burschowsky, Daniel; Bjørnestad, Victoria Ariel; Hodnik, Vesna; Anderluh, Gregor; Krengel, Ute

    2016-01-01

    Cholera is the prime example of blood-group-dependent diseases, with individuals of blood group O experiencing the most severe symptoms. The cholera toxin is the main suspect to cause this relationship. We report the high-resolution crystal structures (1.1–1.6 Å) of the native cholera toxin B-pentamer for both classical and El Tor biotypes, in complexes with relevant blood group determinants and a fragment of its primary receptor, the GM1 ganglioside. The blood group A determinant binds in the opposite orientation compared to previously published structures of the cholera toxin, whereas the blood group H determinant, characteristic of blood group O, binds in both orientations. H-determinants bind with higher affinity than A-determinants, as shown by surface plasmon resonance. Together, these findings suggest why blood group O is a risk factor for severe cholera. PMID:27082955

  8. Cholera Prevention and Control

    Science.gov (United States)

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

  9. 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.

  10. Colera y Vibrio cholerae Cholera and Vibrio cholerae

    OpenAIRE

    Sandra Fernandez F; Guillermina Alonso

    2009-01-01

    El Colera es una diarrea infecciosa aguda producida por Vibrio cholerae. La transmision se produce predominantemente a traves de agua o alimentos contaminados. La administracion de antibioticos puede disminuir la severidad de los sintomas. A partir de 1977, se han caracterizado cepas de V.cholerae O1 con resistencia multiple a los antibioticos. Los determinantes de resistencia han sido reportados principalmente asociados a plasmidos e integrones. Historicamente, solo las cepas del serogrupo O...

  11. 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.

  12. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Anisia J Silva

    2016-02-01

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

  13. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-04

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

  15. 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.

  16. 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.

  17. 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.

  18. Cholera in Azov area

    Directory of Open Access Journals (Sweden)

    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

  19. 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

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

    Science.gov (United States)

    Eibach, Daniel; Herrera-León, Silvia; Gil, Horacio; Hogan, Benedikt; Ehlkes, Lutz; Adjabeng, Michael; Kreuels, Benno; Nagel, Michael; Opare, David; Fobil, Julius N; May, Jürgen

    2016-01-01

    Background Ghana is affected by regular cholera epidemics and an annual average of 3,066 cases since 2000. In 2014, Ghana experienced one of its largest cholera outbreaks within a decade with more than 20,000 notified infections. In order to attribute this rise in cases to a newly emerging strain or to multiple simultaneous outbreaks involving multi-clonal strains, outbreak isolates were characterized, subtyped and compared to previous epidemics in 2011 and 2012. Methodology/Principal Findings Serotypes, biotypes, antibiotic susceptibilities were determined for 92 Vibrio cholerae isolates collected in 2011, 2012 and 2014 from Southern Ghana. For a subgroup of 45 isolates pulsed-field gel electrophoresis, multilocus sequence typing and multilocus-variable tandem repeat analysis (MLVA) were performed. Eighty-nine isolates (97%) were identified as ctxB (classical type) positive V. cholerae O1 biotype El Tor and three (3%) isolates were cholera toxin negative non-O1/non-O139 V. cholerae. Among the selected isolates only sulfamethoxazole/trimethoprim resistance was detectable in 2011, while 95% of all 2014 isolates showed resistance towards sulfamethoxazole/trimethoprim, ampicillin and reduced susceptibility to ciprofloxacin. MLVA achieved the highest subtype discrimination, revealing 22 genotypes with one major outbreak cluster in each of the three outbreak years. Apart from those clusters genetically distant genotypes circulate during each annual epidemic. Conclusions/Significance This analysis suggests different endemic reservoirs of V. cholerae in Ghana with distinct annual outbreak clusters accompanied by the occurrence of genetically distant genotypes. Preventive measures for cholera transmission should focus on aquatic reservoirs. Rapidly emerging multidrug resistance must be monitored closely. PMID:27232338

  1. Prevalence and characterization of Vibrio cholerae isolated from shrimp products imported into Denmark

    DEFF Research Database (Denmark)

    Dalsgaard, A.; Bjergskov, T.; Jeppesen, V.F.;

    1996-01-01

    A total of 3,555 metric tonnes of warm water shrimp were imported into Denmark from December 1994 to July 1995. V. cholerae O1 was not detected in any of the 748 samples analyzed. Non-Ol V. cholerae was found in a single (0.1%) cooked frozen shrimp product and in five (0.7%) raw frozen products...... contained plasmids or genes encoding cholera toxin (CT) or heat-stable enterotoxin (NAG-ST), The absence of V. cholerae O1 and the low number of samples containing CT and NAG-ST negative non-Ol strains in imported shrimp suggest that I! cholerae in such products may not constitute a public health problem....

  2. Synthetic peptides with antigenic specificity for bacterial toxins.

    Science.gov (United States)

    Sela, M; Arnon, R; Jacob, C O

    1986-01-01

    The attachment of a diphtheria toxin-specific synthetic antigenic determinant and a synthetic adjuvant to a synthetic polymeric carrier led to production of a totally synthetic macromolecule which provoked protective antibodies against diphtheria when administered in aqueous solution. When peptides related to the B subunit of cholera toxin were synthesized and attached to tetanus toxoid, antibodies produced against the conjugate reacted in some but not all cases with intact cholera toxin and (especially with peptide CTP 3, residues 50-64) neutralized toxin reactivity, as tested by permeability in rabbit skin, fluid accumulation in ligated small intestinal loops and adenylate cyclase activation. Polymerization of the peptide without any external carrier, or conjugation with the dipalmityl lysine group, had as good an effect in enhancing the immune response as its attachment to tetanus toxoid. Prior exposure to the carrier suppressed the immune response to the epitope attached to it, whereas prior exposure to the synthetic peptide had a good priming effect when the intact toxin was given; when two different peptides were attached to the same carrier, both were expressed. Antisera against peptide CTP 3 were highly cross-reactive with the heat-labile toxin of Escherichia coli and neutralized it to the same extent as cholera toxin, which is not surprising in view of the great homology between the two proteins. A synthetic oligonucleotide coding for CTP 3 has been used to express the peptide in a form suitable for immunization. It led to a priming effect against the intact cholera toxin. PMID:2426052

  3. 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

  4. 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, ...

  5. 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...

  6. Retrograde transport of protein toxins through the Golgi apparatus

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; Skotland, Tore; van Deurs, Bo; Klokk, Tove Irene

    2013-01-01

    A number of protein toxins from plants and bacteria take advantage of transport through the Golgi apparatus to gain entry into the cytosol where they exert their action. These toxins include the plant toxin ricin, the bacterial Shiga toxins, and cholera toxin. Such toxins bind to lipids or proteins...... at the cell surface, and they are endocytosed both by clathrin-dependent and clathrin-independent mechanisms. Sorting to the Golgi and retrograde transport to the endoplasmic reticulum (ER) are common to these toxins, but the exact mechanisms turn out to be toxin and cell-type dependent. In the ER......, the enzymatically active part is released and then transported into the cytosol, exploiting components of the ER-associated degradation system. In this review, we will discuss transport of different protein toxins, but we will focus on factors involved in entry and sorting of ricin and Shiga toxin...

  7. 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...

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

    Directory of Open Access Journals (Sweden)

    Lucantonio Debellis

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

  9. Genome Sequencing Reveals Unique Mutations in Characteristic Metabolic Pathways and the Transfer of Virulence Genes between V. mimicus and V. cholerae

    Science.gov (United States)

    Zhou, Yanyan; Zhang, Qiuxiang; Zhang, Fanfei; Du, Pengcheng; Wang, Shujing; Chen, Chen; Kan, Biao

    2011-01-01

    Vibrio mimicus, the species most similar to V. cholerae, is a microbe present in the natural environmental and sometimes causes diarrhea and internal infections in humans. It shows similar phenotypes to V. cholerae but differs in some biochemical characteristics. The molecular mechanisms underlying the differences in biochemical metabolism between V. mimicus and V. cholerae are currently unclear. Several V. mimicus isolates have been found that carry cholera toxin genes (ctxAB) and cause cholera-like diarrhea in humans. Here, the genome of the V. mimicus isolate SX-4, which carries an intact CTX element, was sequenced and annotated. Analysis of its genome, together with those of other Vibrio species, revealed extensive differences within the Vibrionaceae. Common mutations in gene clusters involved in three biochemical metabolism pathways that are used for discrimination between V. mimicus and V. cholerae were found in V. mimicus strains. We also constructed detailed genomic structures and evolution maps for the general types of genomic drift associated with pathogenic characters in polysaccharides, CTX elements and toxin co-regulated pilus (TCP) gene clusters. Overall, the whole-genome sequencing of the V. mimicus strain carrying the cholera toxin gene provides detailed information for understanding genomic differences among Vibrio spp. V. mimicus has a large number of diverse gene and nucleotide differences from its nearest neighbor, V. cholerae. The observed mutations in the characteristic metabolism pathways may indicate different adaptations to different niches for these species and may be caused by ancient events in evolution before the divergence of V. cholerae and V. mimicus. Horizontal transfers of virulence-related genes from an uncommon clone of V. cholerae, rather than the seventh pandemic strains, have generated the pathogenic V. mimicus strain carrying cholera toxin genes. PMID:21731695

  10. Genome sequencing reveals unique mutations in characteristic metabolic pathways and the transfer of virulence genes between V. mimicus and V. cholerae.

    Directory of Open Access Journals (Sweden)

    Duochun Wang

    Full Text Available Vibrio mimicus, the species most similar to V. cholerae, is a microbe present in the natural environmental and sometimes causes diarrhea and internal infections in humans. It shows similar phenotypes to V. cholerae but differs in some biochemical characteristics. The molecular mechanisms underlying the differences in biochemical metabolism between V. mimicus and V. cholerae are currently unclear. Several V. mimicus isolates have been found that carry cholera toxin genes (ctxAB and cause cholera-like diarrhea in humans. Here, the genome of the V. mimicus isolate SX-4, which carries an intact CTX element, was sequenced and annotated. Analysis of its genome, together with those of other Vibrio species, revealed extensive differences within the Vibrionaceae. Common mutations in gene clusters involved in three biochemical metabolism pathways that are used for discrimination between V. mimicus and V. cholerae were found in V. mimicus strains. We also constructed detailed genomic structures and evolution maps for the general types of genomic drift associated with pathogenic characters in polysaccharides, CTX elements and toxin co-regulated pilus (TCP gene clusters. Overall, the whole-genome sequencing of the V. mimicus strain carrying the cholera toxin gene provides detailed information for understanding genomic differences among Vibrio spp. V. mimicus has a large number of diverse gene and nucleotide differences from its nearest neighbor, V. cholerae. The observed mutations in the characteristic metabolism pathways may indicate different adaptations to different niches for these species and may be caused by ancient events in evolution before the divergence of V. cholerae and V. mimicus. Horizontal transfers of virulence-related genes from an uncommon clone of V. cholerae, rather than the seventh pandemic strains, have generated the pathogenic V. mimicus strain carrying cholera toxin genes.

  11. Insights on the trafficking and retro-translocation of glycosphingolipid-binding bacterial toxins

    OpenAIRE

    Cho, Jin A.; Chinnapen, Daniel J.-F.; Aamar, Emil; te Welscher, Yvonne M.; Lencer, Wayne I.; Massol, Ramiro

    2012-01-01

    Some bacterial toxins and viruses have evolved the capacity to bind mammalian glycosphingolipids to gain access to the cell interior, where they can co-opt the endogenous mechanisms of cellular trafficking and protein translocation machinery to cause toxicity. Cholera toxin (CT) is one of the best-studied examples, and is the virulence factor responsible for massive secretory diarrhea seen in cholera. CT enters host cells by binding to monosialotetrahexosylganglioside (GM1 gangliosides) at th...

  12. Inhibition of heat-labile cholera and Escherichia coli enterotoxins by brefeldin A.

    Science.gov (United States)

    Donta, S T; Beristain, S; Tomicic, T K

    1993-08-01

    Cholera enterotoxin and the related heat-labile enterotoxins of Escherichia coli enter their target cells through noncoated vesicles, but how the toxins are processed intracellularly and how they get to their targeted enzyme, adenylate cyclase, remain to be defined. Brefeldin A, an inhibitor of the trans-Golgi network, is shown herein to transiently block the morphologic and enzymatic effects of the toxin at a step distal to the initial binding process but prior to activation of adenylate cyclase by the toxin. It is likely, therefore, that these toxins are processed by the Golgi apparatus before trafficking to the membrane adenylate cyclase. PMID:8392970

  13. [Cases of gastroenteritis associated to Vibrio cholerae no 01 in Oran, Salta].

    Science.gov (United States)

    Rivas, M; Cacace, M L; Ayala, L T; Baschkier, A; Miliwebsky, E; Caffer, M I

    1996-01-01

    Forty-one sporadic cases of non-O group 1 Vibrio cholerae gastroenteritis were detected in Orán, Salta, between February 1992 and February 1995. The frequency of isolation was 0.9% of the diarrhea cases. Out of 41 patients, 21 (51.2%) were older than 15 years and 25 (60.9%) were male. All the patients had diarrhea, 24 (58.5%) had watery stools and 6 (14.6%) cholera-like diarrhea; 10 (24.4%) presented vomiting and 12 (29%) mild dehydration. Six malnourished children who suffered from diarrhea with moderate dehydration for more than a week, were hospitalized. V. cholerae non O1 and Shigella flexneri were isolated from one patient, during the first outbreak and V. cholerae non O1 and Salmonella IV 50:b:- were recovered simultaneously from another patient during the fourth outbreak. A 72 year old woman died during the second cholera outbreak. The symptoms were: watery diarrhea, vomiting, fever and mild dehydration. A strain of V. cholerae O5, that did not produce cholera toxin, heat-stable enterotoxin, Kanagawa-like hemolysin or verocitotoxin was detected. It was positive for El Tor hemolysin and D-mannose and L-fucose resistant cells-associated hemagglutinins. Among the 41 isolates studied, all were oxidase and indole positive, fermented glucose, saccharose and mannitol. They were all motile, produced lysine and ornithine decarboxylases but not arginine dihydrolase or hydrogen sulfide. They were sensitive to O129 vibriostatic compound. None of them belonged to O1 or O139 serogroup and they did not produce cholera troxin. Among the V. cholerae non O1 strains isolated, 9.5% were resistant to ampicillin and 4.9% to trimethoprim-sulfamethoxazole. Active surveillance had shown that V. cholerae non-O1 is not an important agent of diarrhea in Orán, Salta. PMID:9102658

  14. 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.

  15. 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.

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

    KAUST Repository

    Weynberg, Karen D.

    2015-12-08

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

  17. [Cholera++ epidemic in Kenya].

    Science.gov (United States)

    Paugam, H

    1999-03-01

    A cholera epidemic in 1997 followed on the heels of the 1992 epidemic that claimed thousands of victims in Kenya. This time, it emerged in the Migori district near the Tanzanian border, when a woman who had married in Tanzania brought her five-month-old baby to visit her parents. The infant, who contracted serious diarrhea and vomiting, died before the mother could reach a dispensary. During the funeral, a perfect opportunity for the disease to spread, those attending observed the traditional ritual of touching the corpse, and then ate and drank with the next of kin. Many developed symptoms of cholera, and several died in the next few days, even before first aid could be administered. At the Public Health Laboratory in Nairobi, analyses confirmed the presence of the Ogawa strain of Vibrio cholerae. Given the global reputation of Médecins Sans Frontières [Doctors Without Borders] in the field of cholera, the head of public health for Homa Bay District issued a call for help in August 1997, asking the team to provide preventive solutions and assess the gravity of the situation. Despite intense logistical, technical and health initiatives, the epidemic spread like wildfire. Five months after the initial outbreak, in February 1998, two Canadian nurses working for MSF in Homa Bay hurriedly surveyed the situation in Nyanza Province, which has a population of three million. The author accompanied one of these nurses, Joceline Roy, a Quebecer in her forties, on a tour that lasted more than 15 hours. Roy worked conscientiously, with great precision and energy. This narrative conveys much more than the fatigue and hazards of travel in the developing world; it tells the story of an important, but little publicized, aspect of nursing. PMID:10362941

  18. 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

  19. Cholera in Vietnam: changes in genotypes and emergence of class I integrons containing aminoglycoside resistance gene cassettes in vibrio cholerae O1 strains isolated from 1979 to 1996.

    Science.gov (United States)

    Dalsgaard, A; Forslund, A; Tam, N V; Vinh, D X; Cam, P D

    1999-03-01

    The number of cholera cases and the mortality rates reported from different regions of Vietnam varied considerably in the period from 1979 to 1996, with between 2,500 and 6,000 cases reported annually from 1992 to 1995. Annual mortality rates ranged from 2.0 to 9.6% from 1979 to 1983 to less than 1.8% after 1983. Major cholera outbreaks were reported from the High Plateau region for the first time in 1994 and 1995; this is an area with limited access to health services and safe drinking-water supplies. All cases were associated with Vibrio cholerae O1. Using ribotyping, cholera toxin (CT) genotyping, and characterization of antibiotic susceptibility patterns and antibiotic resistance genes by PCR, we show that strains isolated after 1990 were clearly different from strains isolated before 1991. In contrast to strains isolated before 1991, 94% of 104 strains isolated after 1990 showed an identical ribotype R1, were resistant to sulfamethoxazole and streptomycin, and showed a different CT genotype. Furthermore, PCR analysis revealed that sulfamethoxazole-resistant strains harbored class I integrons containing a gene cassette ant(3")-1a encoding resistance to streptomycin and spectinomycin. This is, to our knowledge, the first report of class I integrons in V. cholerae. The development of cholera and the changes in the phenotypic and genotypic properties of V. cholerae O1 shown in the present study highlight the importance of monitoring V. cholerae O1 in Vietnam as in other parts of the world. In particular, the emergence of the new ribotype R1 strain containing class I integrons should be further studied. PMID:9986842

  20. ToxR interferes with CRP-dependent transcriptional activation of ompT in Vibrio cholerae

    OpenAIRE

    Li, Caiyi C.; Merrell, D. Scott; Camilli, Andrew; Kaper*, James B.

    2002-01-01

    In pathogenic Vibrio cholerae, the transmembrane DNA-binding protein ToxR co-ordinates the expression of over 20 genes, including those encoding important virulence factors such as cholera toxin and the toxin-co-regulated pilus. The outer membrane protein OmpT is the only member of the ToxR regulon known to be repressed by ToxR. In this study, we examined the environmental conditions that regulate OmpT expression and demonstrated that ompT transcription is upregulated 14-fold when the bacteri...

  1. 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.

  2. 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

  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. vttRA and vttRB Encode ToxR Family Proteins That Mediate Bile-Induced Expression of Type Three Secretion System Genes in a Non-O1/Non-O139 Vibrio cholerae Strain▿

    OpenAIRE

    Alam, Ashfaqul; Tam, Vincent; Hamilton, Elaine; Dziejman, Michelle

    2010-01-01

    Strain AM-19226 is a pathogenic non-O1/non-O139 serogroup Vibrio cholerae strain that does not encode the toxin-coregulated pilus or cholera toxin but instead causes disease using a type three secretion system (T3SS). Two genes within the T3SS pathogenicity island, herein named vttRA (locus tag A33_1664) and vttRB (locus tag A33_1675), are predicted to encode proteins that show similarity to the transcriptional regulator ToxR, which is found in all strains of V. cholerae. Strains with a delet...

  5. 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...

  6. 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...

  7. 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.

  8. 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

  9. 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.)

  10. 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

  11. 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

  12. 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.

  13. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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...

  16. Glucose- but Not Rice-Based Oral Rehydration Therapy Enhances the Production of Virulence Determinants in the Human Pathogen Vibrio cholerae

    Science.gov (United States)

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

    2014-01-01

    Despite major attempts to prevent cholera transmission, millions of people worldwide still must address this devastating disease. Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT), whereby water and electrolytes are replenished. Commonly distributed oral rehydration salts also contain glucose. Here, we analyzed the effects of glucose and alternative carbon sources on the production of virulence determinants in the causative agent of cholera, the bacterium Vibrio cholerae during in vitro experimentation. We demonstrate that virulence gene expression and the production of cholera toxin are enhanced in the presence of glucose or similarly transported sugars in a ToxR-, TcpP- and ToxT-dependent manner. The virulence genes were significantly less expressed if alternative non-PTS carbon sources, including rice-based starch, were utilized. Notably, even though glucose-based ORT is commonly used, field studies indicated that rice-based ORT performs better. We therefore used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORT could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti. Our results strongly support a change of carbon source for the treatment of cholera, especially in epidemic settings. PMID:25474211

  17. Polyamine toxins

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Jensen, Lars S; Vogensen, Stine B

    2005-01-01

    Polyamine toxins, isolated from spiders and wasps, have been used as pharmacological tools for the study of ionotropic receptors, but their use have so far been hampered by their lack of selectivity. In this mini-review, we describe how careful synthetic modification of native polyamine toxins ha...

  18. 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) ...

  19. 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

  20. 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.

  1. 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.

  2. 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. PMID:24106192

  3. Mechanisms of immune regulation by norepinephrine and cholera toxin

    International Nuclear Information System (INIS)

    Norepinephrine has previously been demonstrated by this laboratory to potentiate the in vitro T-dependent antibody response through the stimulation of β-adrenergic receptors. The role of β-adrenergic receptor subtypes in norepinephrine-induced potentiation of the antibody responses was examined with selective β-adrenergic antagonists. The antagonists were metoprolol (β1-selective), ICI 118-551 (β2-selective), and propranolol (β-non-selective). Both propranolol and ICI 118-551 blocked norepinephrine-induced potentiation of the antibody response, but metoprolol was ineffective. Receptor binding competition of antagonists with the radioligant, [3H]CGP-12177 was examined and results were analyzed with the computer program, LIGAND. Competition by ICI 118-551 identified 75% β2- and 25% β1-adrenergic receptors on splenic mononuclear cells. Enriched T lymphocytes exhibited 75% β2-adrenergic receptors, while enriched B lymphocytes contained 90% β2-adrenergic receptors as identified by ICI 118-551. Greater than twice as many total receptors were identified on B lymphocytes than T lymphocytes. A T cell lymphoma contained about 60% β2-receptors, while 100% were β2 receptors on a B cell lymphoma, as assessed by ICI 118-551. Results support a heterogeneous β-adrenergic receptor population on T lymphocytes and a more homogeneous β2-population on B lymphocytes

  4. Mechanisms of immune regulation by norepinephrine and cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, K.S.

    1988-01-01

    Norepinephrine has previously been demonstrated by this laboratory to potentiate the in vitro T-dependent antibody response through the stimulation of {beta}-adrenergic receptors. The role of {beta}-adrenergic receptor subtypes in norepinephrine-induced potentiation of the antibody responses was examined with selective {beta}-adrenergic antagonists. The antagonists were metoprolol ({beta}{sub 1}-selective), ICI 118-551 ({beta}{sub 2}-selective), and propranolol ({beta}-non-selective). Both propranolol and ICI 118-551 blocked norepinephrine-induced potentiation of the antibody response, but metoprolol was ineffective. Receptor binding competition of antagonists with the radioligant, ({sup 3}H)CGP-12177 was examined and results were analyzed with the computer program, LIGAND. Competition by ICI 118-551 identified 75% {beta}{sub 2}- and 25% {beta}{sub 1}-adrenergic receptors on splenic mononuclear cells. Enriched T lymphocytes exhibited 75% {beta}{sub 2}-adrenergic receptors, while enriched B lymphocytes contained 90% {beta}{sub 2}-adrenergic receptors as identified by ICI 118-551. Greater than twice as many total receptors were identified on B lymphocytes than T lymphocytes. A T cell lymphoma contained about 60% {beta}{sub 2}-receptors, while 100% were {beta}{sub 2} receptors on a B cell lymphoma, as assessed by ICI 118-551. Results support a heterogeneous {beta}-adrenergic receptor population on T lymphocytes and a more homogeneous {beta}{sub 2}-population on B lymphocytes.

  5. Influence of bacterial toxins on the GTPase activity of transducin from bovine retinal rod outer segments

    International Nuclear Information System (INIS)

    The action of cholera toxin, capable of ADP-ribosylation of the activator N/sub s/ protein, and pertussis toxin, capable of ADP-ribosylation of the inhibitor N/sub i/ protein of the adenylate cyclase complex, on transducin, the GTP-binding protein of the rod outer segments of the retina, was investigated. It was shown that under the action of pertussis and cholera toxins, the GTPase activity of transducin is inhibited. Pertussin toxin inhibits the GTPase of native retinal rod outer segments by 30-40%, while GTPase of homogeneous transducin produces a 70-80% inhibition. The action of toxins on transducin depends on the presence and nature of the guanylic nucleotide with which incubation is performed. On the basis of the data obtained it is suggested that pertussis toxin interacts with pretransducin and with the transducin-GDP complex, while cholera toxin ADP-ribosylates the transducin-GTP complex and does not act on transducin lacking GTP

  6. Botulinum toxin.

    OpenAIRE

    Savardekar Preeti

    1989-01-01

    Botulinum toxin, one of the most poisonous biological substances known, is a neurotoxin produced by the bacterium Clostridium botulinum. C. botulinum elaborates eight antigenically distinguishable exotoxins (A, B, C 1 , C 2 , D, E, F and G). All serotypes interfere with neural transmission by blocking the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. The weakness induced by injection with botulinum toxin A usually lasts about...

  7. 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

  8. 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

  9. 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.

  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 expr...... expression during infection of the rabbit ligated ileal loop model of cholera. Genes encoding the toxin-coregulated pilus (TCP) and cholera toxin (CT) were powerfully expressed early in the infectious process in bacteria adjacent to epithelial surfaces. Increased growth was found to co......-localize with virulence gene expression. Significant heterogeneity in the expression of tcpA, the repeating subunit of TCP, was observed late in the infectious process. The expression of tcpA, studied in single cells in a homogeneous medium, demonstrated unimodal induction of tcpA after addition of bicarbonate......, a chemical inducer of virulence gene expression. Striking bifurcation of the population occurred during entry into stationary phase: one subpopulation continued to express tcpA, whereas the expression declined in the other subpopulation. ctxA, encoding the A subunit of CT, and toxT, encoding the proximal...

  11. Small Molecule-Induced Allosteric Activation of the Vibrio Cholerae RTX Cysteine Protease Domain

    Energy Technology Data Exchange (ETDEWEB)

    Lupardus, P.J.; Shen, A.; Bogyo, M.; Garcia, K.C.

    2009-05-19

    Vibrio cholerae RTX (repeats in toxin) is an actin-disrupting toxin that is autoprocessed by an internal cysteine protease domain (CPD). The RTX CPD is efficiently activated by the eukaryote-specific small molecule inositol hexakisphosphate (InsP{sub 6}), and we present the 2.1 angstrom structure of the RTX CPD in complex with InsP{sub 6}. InsP{sub 6} binds to a conserved basic cleft that is distant from the protease active site. Biochemical and kinetic analyses of CPD mutants indicate that InsP{sub 6} binding induces an allosteric switch that leads to the autoprocessing and intracellular release of toxin-effector domains.

  12. 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.

  13. 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.

  14. 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

  15. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-01-01

    Full Text Available After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1 positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR; 2 of these were also ctxA (cholera toxin positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR, and pulsed field gel electrophoresis (PFGE. The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012 and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  16. Would Cholera become a Neglected Tropical Disease?

    Directory of Open Access Journals (Sweden)

    Anil K. Bhola

    2011-07-01

    Full Text Available Cholera is a serious public health problem, particularly in Africa, Asia, South and Central America. Similar to the neglected tropical diseases (NTD, it is common in places with unsafe water, poor sanitation and limited access to the basic health care. In the concurrent times when the world is shrinking into a Global village, the definition of NTD itself has lost significance owing to rapid transmission of such diseases. Even, the cholera non-endemic developed countries in Europe, Russia and Oceania have become vulnerable to imported cholera. The seventh pandemic of cholera is in its 51st year without any sign of abatement despite improvements in sanitation, safe drinking water supply, promotion of oral rehydration therapy and availability of alternative preventive interventions like oral cholera vaccines. Cholera is markedly under reported due to a myriad of reasons including economic ones. The under reporting is also resulted from weakening surveillance system across countries which in turn contributes to changing perceptions and attitudes on burden of the disease and deteriorating public health services. In addition to this, lack of evidence-based sector wide programmatic approach and inequitable resource allocation for prevention and control of cholera may also risk the disease to become a NTD in future.

  17. [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

  18. Designing an efficient multi-epitope peptide vaccine against Vibrio cholerae via combined immunoinformatics and protein interaction based approaches.

    Science.gov (United States)

    Nezafat, Navid; Karimi, Zeinab; Eslami, Mahboobeh; Mohkam, Milad; Zandian, Sanam; Ghasemi, Younes

    2016-06-01

    Cholera continues to be a major global health concern. Among different Vibrio cholerae strains, only O1 and O139 cause acute diarrheal diseases that are related to epidemic and pandemic outbreaks. The currently available cholera vaccines are mainly lived and attenuated vaccines consisting of V. cholerae virulence factors such as toxin-coregulated pili (TCP), outer membrane proteins (Omps), and nontoxic cholera toxin B subunit (CTB). Nowadays, there is a great interest in designing an efficient epitope vaccine against cholera. Epitope vaccines consisting of immunodominant epitopes and adjuvant molecules enhance the possibility of inciting potent protective immunity. In this study, V. cholerae protective antigens (OmpW, OmpU, TcpA and TcpF) and the CTB, which is broadly used as an immunostimulatory adjuvant, were analyzed using different bioinformatics and immunoinformatics tools. The common regions between promiscuous epitopes, binding to various HLA-II supertype alleles, and B-cell epitopes were defined based upon the aforementioned protective antigens. The ultimately selected epitopes and CTB adjuvant were fused together using proper GPGPG linkers to enhance vaccine immunogenicity. A three-dimensional model of the thus constructed vaccine was generated using I-TASSER. The model was structurally validated using the ProSA-web error-detection software and the Ramachandran plot. The validation results indicated that the initial 3D model needed refinement. Subsequently, a high-quality model obtained after various refinement cycles was used for defining conformational B-cell epitopes. Several linear and conformational B-cell epitopes were determined within the epitope vaccine, suggesting likely antibody triggering features of our designed vaccine. Next, molecular docking was performed between the 3D vaccine model and the tertiary structure of the toll like receptor 2 (TLR2). To gain further insight into the interaction between vaccine and TLR2, molecular dynamics

  19. El plasmidio críptico pTLC de Vibrio cholerae podría ser un vestigio evolutivo del genoma de un fago filamentoso

    OpenAIRE

    Lourdes Proenza; Edith Suzarte; Talena Ledón; Karen Marrero; Boris Luis Rodríguez; Rafael Fando; Javier Campos

    2007-01-01

    El elemento críptico ligado a la toxina (TLC, del inglés, toxin-linked criptic) es una secuencia duplicada en tándem de alrededor de 4,7 kb localizada cuesta arriba del profago CTX¿ en el cromosoma de Vibrio cholerae. TLC se encuentra en la mayoría de las cepas de V .cholerae que expresan la toxina colérica y el pilus corregulado con la toxina, dos factores de virulencia esenciales en este microorganis-mo. Algunos descubrimientos previos sugieren que TLC está relacionado con los bacteriófagos...

  20. Botox (Botulinum Toxin)

    Science.gov (United States)

    ... and rashes clinical tools newsletter | contact Share | Botox (Botulinum Toxin) A A A BEFORE: Crow's feet before Botox ... wrinkles. One such procedure involves the use of botulinum toxin injections. Botulinum toxin is produced by the fermentation ...

  1. 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...

  2. O-Specific Polysaccharide-Specific Memory B Cell Responses in Young Children, Older Children, and Adults Infected with Vibrio cholerae O1 Ogawa in Bangladesh.

    Science.gov (United States)

    Aktar, Amena; Rahman, M Arifur; Afrin, Sadia; Faruk, M Omar; Uddin, Taher; Akter, Aklima; Sami, M Israk Nur; Yasmin, Tahirah; Chowdhury, Fahima; Khan, Ashraful I; Leung, Daniel T; LaRocque, Regina C; Charles, Richelle C; Bhuiyan, Taufiqur Rahman; Mandlik, Anjali; Kelly, Meagan; Kováč, Pavol; Xu, Peng; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; Ryan, Edward T

    2016-05-01

    Cholera caused by Vibrio cholerae O1 confers at least 3 to 10 years of protection against subsequent disease regardless of age, despite a relatively rapid fall in antibody levels in peripheral blood, suggesting that memory B cell responses may play an important role in protection. The V. cholerae O1-specific polysaccharide (OSP) component of lipopolysaccharide (LPS) is responsible for serogroup specificity, and it is unclear if young children are capable of developing memory B cell responses against OSP, a T cell-independent antigen, following cholera. To address this, we assessed OSP-specific memory B cell responses in young children (2 to 5 years, n = 11), older children (6 to 17 years, n = 21), and adults (18 to 55 years, n = 28) with cholera caused by V. cholerae O1 in Dhaka, Bangladesh. We also assessed memory B cell responses against LPS and vibriocidal responses, and plasma antibody responses against OSP, LPS, and cholera toxin B subunit (CtxB; a T cell-dependent antigen) on days 2 and 7, as well as days 30, 90, and 180 after convalescence. In all age cohorts, vibriocidal responses and plasma OSP, LPS, and CtxB-specific responses peaked on day 7 and fell toward baseline over the follow-up period. In comparison, we were able to detect OSP memory B cell responses in all age cohorts of patients with detectable responses over baseline for 90 to 180 days. Our results suggest that OSP-specific memory B cell responses can occur following cholera, even in the youngest children, and may explain in part the age-independent induction of long-term immunity following naturally acquired disease. PMID:27009211

  3. 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.

  4. Household Transmission of Vibrio cholerae in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jonathan D Sugimoto

    2014-11-01

    Full Text Available Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures.Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1 direct exposure within the household and 2 contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001 occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%-22.8% risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length. The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%-8.0%. The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%-16.6% and 8.2% (2.1%-27.1% through direct exposure, and 3.4% (1.7%-6.7% and 2.0% (0.5%-7.3% through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered.Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of

  5. Toxin-mediated effects on the innate mucosal defenses: implications for enteric vaccines

    DEFF Research Database (Denmark)

    Glenn, Gregory M; Francis, David H; Danielsen, E Michael

    2009-01-01

    mucosal barrier as a key step in enteric pathogen survival. We review key observations relevant to the roles of LT and cholera toxin in protective immunity and the effects of these toxins on innate mucosal defenses. We suggest either that toxin-mediated fluid secretion mechanically disrupts the mucus...... layer or that toxins interfere with innate mucosal defenses by other means. Such a breach gives pathogens access to the enterocyte, leading to binding and pathogenicity by enterotoxigenic E. coli (ETEC) and other organisms. Given the common exposure to LT(+) ETEC by humans visiting or residing in...... regions of endemicity, barrier disruption should frequently render the gut vulnerable to ETEC and other enteric infections. Conversely, toxin immunity would be expected to block this process by protecting the innate mucosal barrier. Years ago, Peltola et al. (Lancet 338:1285-1289, 1991) observed...

  6. 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.

  7. 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.

  8. Does Water Hyacinth on East African Lakes Promote Cholera Outbreaks?

    OpenAIRE

    Feikin, Daniel R.; Tabu, Collins W.; Gichuki, John

    2010-01-01

    Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate on the floating aquatic plant, water hyacinth, which is periodically widespread in East African lakes since the late 1980s. From 1994 to 2008, Nyanza Province, which is the Kenyan province bordering Lake Victoria, accounted for a larger proportion of cholera cases than expected by its population size (38.7...

  9. 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...

  10. Comparing sociocultural features of cholera in three endemic African settings

    OpenAIRE

    Schaetti, Christian; Sundaram, Neisha; Merten, Sonja; Ali, Said M; Nyambedha, Erick O; Lapika, Bruno; Chaignat, Claire-Lise; Hutubessy, Raymond; Weiss, Mitchell G.

    2013-01-01

    Background Cholera mainly affects developing countries where safe water supply and sanitation infrastructure are often rudimentary. Sub-Saharan Africa is a cholera hotspot. Effective cholera control requires not only a professional assessment, but also consideration of community-based priorities. The present work compares local sociocultural features of endemic cholera in urban and rural sites from three field studies in southeastern Democratic Republic of Congo (SE-DRC), western Kenya and Za...

  11. 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...

  12. 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.

  13. 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.

  14. Cholera in Pregnancy: Outcomes from a Specialized Cholera Treatment Unit for Pregnant Women in Léogâne, Haiti

    OpenAIRE

    Ciglenecki, Iza; Bichet, Mathieu; Tena, Javier; Mondesir, Erneau; Bastard, Mathieu; Tran, Nguyen-Toan; Antierens, Annick; Staderini, Nelly

    2013-01-01

    Background The association between cholera in pregnancy and negative fetal outcome has been described since the 19th century. However, there is limited published literature on the subject. We describe pregnancy outcomes from a specialized multidisciplinary hospital unit at the onset of a large cholera outbreak in Haiti in 2010 and 2011. Methods Pregnant women with cholera were hospitalized in a specialized unit within the MSF hospital compound in Léogâne and treated using standard cholera tre...

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

    Science.gov (United States)

    Choi, Seon Young; Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Huq, Anwar; Cravioto, Alejandro

    2016-01-01

    ABSTRACT 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. PMID:26980836

  16. Conformation of protein secreted across bacterial outer membranes: a study of enterotoxin translocation from Vibrio cholerae

    International Nuclear Information System (INIS)

    The secretion of enterotoxin by Vibrio cholerae is punctuated by the transient entry of the toxin subunits into the periplasm. In this paper, the authors show that the subunits oligomerize into an assembled holotoxin within the periplasm prior to their secretion across the outer membrane. The rate of toxin assembly was studied by pulse-labeling cells with [35S]-methionine and then monitoring the turnover of radiolabeled subunits as they assembled within the periplasm. The subunits entered the periplasm as monomers and assembled into oligomers with a half-time of ≅ 1 min. Since assembly was a rapid event compared to the rate of toxin efflux from the periplasm, which had a half-time of ≅ 13 min, they conclude that all of the subunits that pass through the periplasm assemble before they traverse the outer membrane. The average concentration of subunit monomers and assembled holotoxin within the periplasm was calculated to be ≅ 20 and ≅ 260 μg/ml, respectively. This indicates that the periplasm is a suitably concentrated milieu where spontaneous toxin assembly can occur. These findings suggest that protein movement across bacterial outer membranes, in apparent contrast to export across other biological membranes, involves translocation of polypeptides that have already folded into tertiary and even quaternary conformations

  17. Occurrence, Diversity, and Pathogenicity of Halophilic Vibrio spp. and Non-O1 Vibrio cholerae from Estuarine Waters along the Italian Adriatic Coast

    OpenAIRE

    Barbieri, Elena; Falzano, Loredana; Fiorentini, Carla; Pianetti, Anna; Baffone, Wally; Fabbri, Alessia; Matarrese, Paola; Casiere, Annarita; Katouli, Mohammad; Kühn, Inger; Möllby, Roland; Bruscolini, Francesca; Donelli, Gianfranco

    1999-01-01

    The occurrence, diversity, and pathogenicity of Vibrio spp. were investigated in two estuaries along the Italian Adriatic coast. Vibrio alginolyticus was the predominant species, followed by Vibrio parahaemolyticus, non-O1 Vibrio cholerae, and Vibrio vulnificus. By using a biochemical fingerprinting method, all isolates were grouped into nine phenotypes with similarity levels of 75 to 97.5%. The production of toxins capable of causing cytoskeleton-dependent changes was detected in a large num...

  18. Does water hyacinth on East African lakes promote cholera outbreaks?

    Science.gov (United States)

    Feikin, Daniel R; Tabu, Collins W; Gichuki, John

    2010-08-01

    Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate on the floating aquatic plant, water hyacinth, which is periodically widespread in East African lakes since the late 1980s. From 1994 to 2008, Nyanza Province, which is the Kenyan province bordering Lake Victoria, accounted for a larger proportion of cholera cases than expected by its population size (38.7% of cholera cases versus 15.3% of national population). Yearly water-hyacinth coverage on the Kenyan section of Lake Victoria was positively associated with the number of cholera cases reported in Nyanza Province (r = 0.83; P = 0.0010). Water hyacinth on freshwater lakes might play a role in initiating cholera outbreaks and causing sporadic disease in East Africa. PMID:20682884

  19. 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.

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

    Science.gov (United States)

    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.

    2016-01-01

    Following mass population displacements in South Sudan, preventive cholera vaccination campaigns were conducted in displaced persons camps before a 2014 cholera outbreak. We compare cholera transmission in vaccinated and unvaccinated areas and show vaccination likely halted transmission within vaccinated areas, illustrating the potential for oral cholera vaccine to stop cholera transmission in vulnerable populations. PMID:27192187

  1. 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

  2. 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.

  3. 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...

  4. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Directory of Open Access Journals (Sweden)

    Pawin Pongkorpsakol

    2014-09-01

    Full Text Available Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84 cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+-K(+ ATPases and Na(+-K(+-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+ channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+-activated basolateral K(+ channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  5. *CYANOBACTERIA AND THEIR TOXINS

    Science.gov (United States)

    Cyanobacteria, or blue-green algae, are naturally-occurring contaminants of surface waters worldwide. These photosynthesizing prokaryotes thrive in warm, shallow, nutrient-rich waters. Many produce potent toxins as secondary metabolites. Cyanobacteria toxins have been document...

  6. Botulinum toxin injection - larynx

    Science.gov (United States)

    Injection laryngoplasty; Botox-larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography-guided botulinum toxin treatment; Percutaneous indirect laryngoscopy-guided botulinum toxin Treatment; ...

  7. Stool C. difficile toxin

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003590.htm Stool C. difficile toxin To use the sharing features on this page, please enable JavaScript. The stool C. difficile toxin test detects harmful substances produced by ...

  8. 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.

  9. 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.

  10. 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...

  11. 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).

  12. Bordetella protein toxins

    Czech Academy of Sciences Publication Activity Database

    Mašín, Jiří; Šebo, Peter; Locht, C.

    New York : Elsevier, Academic Press, 2006, s. 291-309. ISBN 978-0-12-088445-2 R&D Projects: GA AV ČR IAA5020406; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50200510 Keywords : pertussis toxin * adenylate cyclase toxin * dermonecrotic toxin Subject RIV: EE - Microbiology, Virology

  13. 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

  14. 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.

  15. 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

  16. Epidemic tvpe and antibiotic resistance of cholera strains isolated%霍乱疫情分离株流行菌型及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    王少玲; 吴捷; 刁保卫; 崔志刚; 王衍德; 朱建华; 黄昌和; 马焱

    2012-01-01

    Objective To assess the epidemic type and antibiotic resistance of cholere strains isolated and to provide basis for clinical treatment and prevention of cholera. Methods Six samples from an outbreak of cholera epidemic were collected in Hainan province in June 2008 and analyzed by serotyping and phage-biotyping. The cholera toxin gene was detected with PCR according to the " Manual for the Prevention and Control of Cholera" (version 5). Pulsed field gel electro-phoresis( PFGE) was used for subtyping of the isolates. The antibiotic susceptibility test of the 6 strains to 17 kinds of antibacterial was determined with improved K-B method recommended by WHO. Results The 6 strains were confirmed as Vibrio cholerae El Tor biotype, with 5 strains of 01 group of Vibrio cholerae El Tor serotype Inaba lc and 1 strains was Vibrio cholerae Ogawa( lc). The cholera toxin gene was identified in all 6 strains. The mapping of the strains were belonged to two pattern by PFGE and the similarity was 100 %. The 6 strains were all resistant to streptomycin,sulphamethoxazole/trim-ethoprim, sulphafurazole, and polymyxin B. High drug susceptibility of the samples was found to 9 kinds of antibiotics such as norfloxacin.cefotaxime and cephalothin(53% ,9/17). Conclusion The bacterium type of Vibrio cholerae causing the epidemic outbreak of cholera was Ol group of Vibrio cholerae El Tor serotype Inaba lc. Norfloxacin.cefotaxime and cepha-lothin could be the choice of clinical treatment for the cases and carriers of Vibrio cholerae in Hainan province. But streptomycin, sulphamethoxazole/trimethoprim,sulphafurazole,and polymyxin B could not be used.%目的 了解霍乱疫情分离株的流行菌型及其耐药性,为霍乱疫情的快速有效控制和临床治疗提供科学依据.方法 对2008年6月海南省某地霍乱疫情采集的6株霍乱弧菌分离株进行血清学分型、噬菌体-生物分型、霍乱毒素基因检测、脉冲场凝胶电泳(PFGE)分子分型

  17. 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.

  18. Independent Regulation of Type VI Secretion in Vibrio cholerae by TfoX and TfoY

    Directory of Open Access Journals (Sweden)

    Lisa C. Metzger

    2016-05-01

    Full Text Available Type VI secretion systems (T6SSs are nanomachines used for interbacterial killing and intoxication of eukaryotes. Although Vibrio cholerae is a model organism for structural studies on T6SSs, the underlying regulatory network is less understood. A recent study showed that the T6SS is part of the natural competence regulon in V. cholerae and is activated by the regulator TfoX. Here, we identify the TfoX homolog TfoY as a second activator of the T6SS. Importantly, despite inducing the same T6SS core machinery, the overall regulons differ significantly for TfoX and TfoY. We show that TfoY does not contribute to competence induction. Instead, TfoY drives the production of T6SS-dependent and T6SS-independent toxins, together with an increased motility phenotype. Hence, we conclude that V. cholerae uses its sole T6SS in response to diverse cues and for distinctive outcomes: either to kill for the prey’s DNA, leading to horizontal gene transfer, or as part of a defensive escape reaction.

  19. Independent Regulation of Type VI Secretion in Vibrio cholerae by TfoX and TfoY.

    Science.gov (United States)

    Metzger, Lisa C; Stutzmann, Sandrine; Scrignari, Tiziana; Van der Henst, Charles; Matthey, Noémie; Blokesch, Melanie

    2016-05-01

    Type VI secretion systems (T6SSs) are nanomachines used for interbacterial killing and intoxication of eukaryotes. Although Vibrio cholerae is a model organism for structural studies on T6SSs, the underlying regulatory network is less understood. A recent study showed that the T6SS is part of the natural competence regulon in V. cholerae and is activated by the regulator TfoX. Here, we identify the TfoX homolog TfoY as a second activator of the T6SS. Importantly, despite inducing the same T6SS core machinery, the overall regulons differ significantly for TfoX and TfoY. We show that TfoY does not contribute to competence induction. Instead, TfoY drives the production of T6SS-dependent and T6SS-independent toxins, together with an increased motility phenotype. Hence, we conclude that V. cholerae uses its sole T6SS in response to diverse cues and for distinctive outcomes: either to kill for the prey's DNA, leading to horizontal gene transfer, or as part of a defensive escape reaction. PMID:27117415

  20. 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)

  1. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

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

    2013-12-01

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

  2. Phenotypic and genetic characteristics of Vibrio cholerae O1 carrying Haitian ctxB and attributes of classical and El Tor biotypes isolated from Silvassa, India.

    Science.gov (United States)

    Das, Moon Moon; Bhotra, Tilothama; Zala, Dolatsinh; Singh, Durg Vijai

    2016-08-01

    Vibrio cholerae O1 biotype El Tor, the causative agent of the seventh pandemic, has recently been replaced by strains carrying classical and Haitian ctxB in India, Haiti and other parts of the world. We conducted phenotypic and genetic tests to characterize V. cholerae O1 isolated between 2012 and 2014 from Silvassa, India, to examine the presence of virulence and regulatory genes, seventh pandemic marker, ctxB type and biofilm formation and to study genomic diversity. Of the 59 V. cholerae O1, eight isolates belong to El Tor prototype, one to classical prototype and the remaining isolates have attributes of both classical and El Tor biotypes. PCR and ctxB gene sequencing revealed the presence of classical ctxB in four strains and Haitian ctxB in 55 isolates; indicating that isolates were either an El Tor or hybrid variant. All isolates carried virulence, regulatory, adherence, Vibrio seventh pandemic pathogenicity island I and seventh pandemic group-specific marker VC2346, in addition to tcpAET and rstRET, the features of seventh pandemic strains, and produced cholera toxin and biofilm. PFGE analysis showed that the majority of isolates are clonal and belong to fingerprint pattern A; however, pattern B is unrelated and patterns C and D are distinct, suggesting considerable diversity in the genomic content among them. These data thus show that isolates from Silvassa are genetically diverse and that Haitian ctxB and hybrid phenotypes are undergoing global dissemination. PMID:27255911

  3. Hybridoma as a specific, sensitive, and ready to use sensing element: a rapid fluorescence assay for detection of Vibrio cholerae O1.

    Science.gov (United States)

    Zamani, Parichehr; Sajedi, Reza H; Hosseinkhani, Saman; Zeinoddini, Mehdi

    2016-09-01

    Over the last decade, isolation and purification of monoclonal antibodies, for diagnostic analysis, have been carried out using the hybridoma expression system. The present study describes a novel example of a detection system using hybridoma cells containing antibody against O1 antigen directly for V. cholerae diagnosis, which is a major health problem in many parts of the world, especially in developing countries. This method has advantages such as simplicity, ease of process, and it does not require manipulation of hybridoma cell. For this approach, an efficient amount of fluorescence calcium indicator, fura 2-AM, was utilized, which emitted light when the intracellular calcium concentration increased as result of antigen binding to specific antibody. More reliable results are obtained via this method and it is considerably faster than other methods, which has the response time of less than 45 s for detection of V. Cholerae O1. Also, the limit of detection was computed to be 50 CFU/mL (cholerae O1. Furthermore, this method was successfully applied to V. cholerae O1 detection in spiked environmental samples, including water and stool samples without any pretreatment. All results reveal that hybridoma cells can provide a valuable, simple, and ready to use tool for rapid detection of other pathogenic bacteria, toxins, and analytes. PMID:27438715

  4. 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

  5. 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.

  6. 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.

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

    DEFF Research Database (Denmark)

    Qureshi, Katja; Mølbak, Kåre; Sandström, Anita;

    2006-01-01

    BACKGROUND: A protective effect of breastfeeding against cholera has been demonstrated in areas endemic of cholera. To assess the protection offered by breast milk from mothers living in an area that had been free from cholera for 7 years, we investigated mothers with cholera and their children d...

  8. 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.

  9. 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.

  10. 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

  11. 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

  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. The Cholera Pandemic, Still with Us after Half a Century: Time to Rethink

    OpenAIRE

    Reyburn, Rita; Deen, Jacqueline L; Grais, Rebecca F.; Sujit K Bhattacharya; Sur, Dipika; Lopez, Anna L; Jiddawi, Mohamed S; Clemens, John D.; von Seidlein, Lorenz

    2011-01-01

    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 ou...

  14. Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

    OpenAIRE

    Kabir, Shahjahan

    2014-01-01

    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...

  15. A 6-Week Oral Toxicity Study of Oral Cholera Vaccine in Sprague-Dawley Rats

    OpenAIRE

    Baek, Yeong-Ok; Choi, Seuk-Keun; Shin, Seo-Ho; Koo, Kyo-Hwan; Choi, Ho-Young; Cha, Seung-Bum; Li, Yong-Chun; Yoo, Hyeon-Jeong; Lee, Joo-Young; Kil, Ki-Hyun; Kim, Hak-Soo; Kang, Min-Soo; Kang, Boo-Hyun; Kim, Kap-Ho; Bae, Jin-Sook

    2012-01-01

    The present study was carried out to examine the toxicity and target organs of oral cholera vaccine (OCV) after repeated oral administration in Sprague-Dawley rats for 6 weeks (3 administrations, once every 2 weeks). OCV is an inactivated oral cholera vaccine that contains Vibrio cholerae and confers protection against cholera caused by V. cholera serogroups O1 (Inaba and Ogawa serotypes) and O139 (strain 4260B). The animals were orally administered either OCV placebo (negative control) or OC...

  16. 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...

  17. 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...

  18. Virulence Gene PCR and PFGE Genotyping analysis of Vibrio cholerae strains isolated from cholera epidemics in Hunan province from 2005 to 2010%湖南省2005年-2010年霍乱疫情分离株的毒力基因PCR及PFGE分型分析

    Institute of Scientific and Technical Information of China (English)

    夏昕; 湛志飞; 覃迪; 刘运芝; 高立冬; 胡世雄; 邓志红; 张红

    2012-01-01

    Objective; To understand the pathogenic characteristics of Vibrio cholerae 0139 strains isolated from Vibrio cholerae epidemics in Hunan province from 2005 to 2010; to study the colone relations among the strains. Methods: K - B method was employed to test drug sensitivity; ctxAB virulence gene was tested by PCR, and finally molecular typing was carried out by pulsed field gel electrophoresis ( PFGE) for representative strains isolated from Vibrio cholerae epidemics. Results; 33 Vibrio cholerae 0139 stains presented a higher drug resistance rate against doxycycline and sulphame -thoxazole of 39. 39% and 75.76% , while a sensitivity of 100% to ciprofloxacin, nor-floxacin and amikacin; The virulence gene PCR results showed all the Vibrio cholerae 0139 strains were cholera toxin genes ctxAB - positive; 24 Vibrio cholerae 0139 strains isolated from Vibrio cholerae epidemics in 2005 and 2010 showed 3 PFGE banding types,and all the strains were homology of 83% - 100% by cluster analysis. Conclusion; Vibrio cholerae 0139 strains isolated from cholera epidemic in Hunan province from 2005 to 2010 were all ctxAB positive. The strains from different years and regions were found the closely related epidemic clone group strains of cholera; Resistance monitoring and further molecular typing analysis of Cholera strains contribute to the efficient surveillance of cholera and infectious source tracking.%目的:了解2005年-2010年湖南省霍乱疫情分离到的O139群霍乱弧菌菌株的病原学特征,研究疫情分离株之间的克隆相关性.方法:采用K-B法进行药敏试验;聚合酶链反应(PCR)检测ctxAB毒力基因;脉冲场凝胶电泳对疫情分离代表株进行PFGE分型分析.结果:33株霍乱弧菌对强力霉素、复方新诺明的耐药率较高,分别为39.39%和75.76%,对环丙沙星、诺氟沙星以及丁胺卡那100%敏感;毒力基因的PCR结果显示为所有疫情分离的O139霍乱弧菌均为产毒株,即

  19. Understanding malarial toxins.

    Science.gov (United States)

    Starkl Renar, Katarina; Iskra, Jernej; Križaj, Igor

    2016-09-01

    Recognized since antiquity, malaria is one of the most infamous and widespread infectious diseases in humans and, although the death rate during the last century has been diminishing, it still accounts for more than a half million deaths annually. It is caused by the Plasmodium parasite and typical symptoms include fever, shivering, headache, diaphoresis and nausea, all resulting from an excessive inflammatory response induced by malarial toxins released into the victim's bloodstream. These toxins are hemozoin and glycosylphosphatidylinositols. The former is the final product of the parasite's detoxification of haeme, a by-product of haemoglobin catabolism, while the latter anchor proteins to the Plasmodium cell surface or occur as free molecules. Currently, only two groups of antimalarial toxin drugs exist on the market, quinolines and artemisinins. As we describe, they both target biosynthesis of hemozoin. Other substances, currently in various phases of clinical trials, are directed towards biosynthesis of glycosylphosphatidylinositol, formation of hemozoin, or attenuation of the inflammatory response of the patient. Among the innovative approaches to alleviating the effects of malarial toxins, is the development of antimalarial toxin vaccines. In this review the most important lessons learned from the use of treatments directed against the action of malarial toxins in antimalarial therapy are emphasized and the most relevant and promising directions for future research in obtaining novel antimalarial agents acting on malarial toxins are discussed. PMID:27353131

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

    Science.gov (United States)

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

    1984-09-01

    To determine the modes of transmission of cholera in the regency of Pidie, Indonesia, and to consider strategies for its control, we set up a laboratory to identify Vibrio cholerae 01 from patients with severe diarrhea in all government clinics in the regency and questioned culture-positive cases and neighborhood controls about possible exposures to V. cholerae 01. Between 12 July and 15 August 1982, 63 of 138 suspected cholera cases were confirmed by the laboratory; 53 of these patients were seen and followed up. We were unable to identify a single, indisputable mode of transmission for cholera which was amenable to immediate control. Nonetheless, a number of factors, including exposure to water from the Tiro-Sigli River and consumption of ice, were associated with disease. Other findings bring into question the value of current practices of chlorinating dugwells and disinfecting homes with Lysol during a cholera outbreak. The case-control approach to investigating the mode of transmission of cholera has distinct limitations when applied in endemic setting where there may not be a single predominant vehicle of transmission, or where the vehicle such as river water is used by all and is only periodically contaminated. PMID:6486303

  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 knowledge of the population about cholera].

    Science.gov (United States)

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

    1996-01-01

    In order to determine the impact of the educational campaign about cholera on the knowledge and believes of the population, a survey was made in 1993 among 1324 persons from 14 provinces and from Isla de la Juventud special municipality. 85% were 20-59 years old and 89% had an secondary basic or higher educational level. 69% had the minimum knowledge to face the disease, 90% would see a doctor if they had and suspicion, 72% knew that diarrhea is the main symptom of cholera, 54% new how it is transmitted 89% thought that they may be infected by drinking water, 54% understood the importance of giving liquids to the sick subject, and 78% realized the significance of washing their hands before eating anf cooking. It is concluded that even though our population has a general knowledge about the disease, due to the fact that our country is located in an endemic zone, health education must be reinforced, specifically those aspects connected with the communication and with the increase of liquids administration to the patients. PMID:9805048

  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. Cell-associated hemagglutinin-deficient mutant of Vibrio cholerae.

    OpenAIRE

    Finn, T M; Reiser, J; Germanier, R.; Cryz, S J

    1987-01-01

    Cell-associated hemagglutinin-negative mutants were derived from cholera enterotoxin-negative Vibrio cholerae JBK70 by Tn5 mutagenesis. One of the mutants identified, SB001, was characterized in greater detail. Its ability to colonize ilea of adult rabbits was determined by feeding approximately 10(8) V. cholerae to each animal. At 17 h after feeding, the numbers of viable vibrios in the ilea were determined. There was a significant, 4 log, decrease in the ability of the hemagglutinin-negativ...

  8. Staphylococcus aureus toxins

    OpenAIRE

    Otto, Michael

    2013-01-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon agai...

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

    Directory of Open Access Journals (Sweden)

    Fernanda S Freitas

    2002-06-01

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

  10. Identification of Critical Amino Acids Conferring Lethality in VopK, a Type III Effector Protein of Vibrio cholerae: Lessons from Yeast Model System

    OpenAIRE

    Bankapalli, Leela Krishna; Mishra, Rahul Chandra; Singh, Balvinder; Raychaudhuri, Saumya

    2015-01-01

    VopK, a type III effector protein, has been implicated in the pathogenesis of Vibrio cholerae strains belonging to diverse serogroups. Ectopic expression of this protein exhibits strong toxicity in yeast model system. In order to map critical residues in VopK, we scanned the primary sequence guided by available data on various toxins and effector proteins. Our in silico analysis of VopK indicated the presence of predicted MCF1-SHE (SHxxxE) serine peptidase domain at the C-terminus region of t...

  11. Survival of Vibrio cholerae O1 on fomites

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  12. Chemical ions affect survival of avian cholera organisms in pondwater

    Science.gov (United States)

    Price, J.I.; Yandell, B.S.; Porter, W.P.

    1992-01-01

    Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

  13. 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...

  14. 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

  15. 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...

  16. Risk of Cholera Among Western and Japanese Travelers.

    Science.gov (United States)

    Wittlinger; Steffen; Watanabe; Handszuh

    1995-09-01

    Background: There has been concern about an increased risk of cholera in travelers to Latin America since the spread of the pandemic to this part of the world. Additionally, before this study the continuous high incidence of imported cholera to Japan had so far not been analyzed. Methods: A retrospective analysis of cases notified in 1991 to national surveillance centers in industrialized countries and to the World Health Organization was carried out. Denominator data were obtained by the World Tourism Organization. Results: The reported rate of imported cholera in European and North American travelers visiting endemic areas remains in the range of 0,2 per 100,000, as was observed 10 years ago. This rate is, however, is manyfold higher in Japanese travelers, with a highest value of 13,0 per 100,000 reported in those returning from Indonesia, usually Bali. No secondary outbreaks were observed in those countries to which cholera was imported. Conclusions: It is assumed that the higher rates in Japanese travelers are mainly due to more intensive surveillance. On Bali and elsewhere, further studies are needed to determine both the role of V. cholerae as a cause of traveler's diarrhea in tourists and to re-evaluate the need for cholera vaccination at specific high-risk destinations. PMID:9815376

  17. Medico - historical study of "Visŭcikă" (Cholera).

    Science.gov (United States)

    Prasad, P V V

    2005-01-01

    The Sanskrit word Visŭcikă refers to a condition in which vitiated văta dŏşa causes pain like pricking with a needle over the body. It occurs in a person suffering with ajĭrna (indigestion) and its detailed description is available in Ayurvedic literature. This disease has its existence in India since ancient times; it has also been referred in Mahăhărata and Tripitikas. Its etiology, signs, symptoms, complications, prognosis and treatment etc. as described in Ayurveda may be correlated with the disease Cholera, which is commonly known as "Haiza" in Hindi. In Greek language, the word Cholera means a flow of bile or the bilious disease. Cholera is an acute infectious diarrheal disease, caused by comma bacillus or vibrio cholerae sero groups 01 or 0139. Aretaetus, Benjamin Rush, Chadwick, John Snow, Robert Koch, etc. were some of the pioneers in Cholera research. Medico- historical importance of Cholera, its transmission, description and references from Ayurvedic texts etc., are being presented in this article. PMID:17333658

  18. [Cholera epidemic in Brescia in 1836].

    Science.gov (United States)

    Vaglia, Alberto

    2013-09-01

    Cholera first made its appearance in Italy in 1836. According to reports of the time the consequences were catastrophic: both the number of the people falling ill and the incidence of mortality were high. On the basis of extensive documentation from various archives, the disease appears to have been known in its clinical aspect but its aetiology remained obscure. Hence physicians were powerless to combat such a scourge. The sense of unease and confusion that accompanied the evolution of these sad events drove the population to the use of religious practices of various kinds. It is still possible to find signs of such devotion in churches, votive chapels and ex voto offerings. PMID:24008858

  19. Diversity and Impact of Prokaryotic Toxins on Aquatic Environments: A Review

    Directory of Open Access Journals (Sweden)

    Rogério Tenreiro

    2010-10-01

    Full Text Available Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS, involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking

  20. Diversity and impact of prokaryotic toxins on aquatic environments: a review.

    Science.gov (United States)

    Valério, Elisabete; Chaves, Sandra; Tenreiro, Rogério

    2010-10-01

    Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS), involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking and irrigation water

  1. 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...

  2. 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)

  3. 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

  4. Cholera Surveillance in Siming District of Xiamen, 2005 -2010%2005-2010年厦门市思明区霍乱监测结果分析

    Institute of Scientific and Technical Information of China (English)

    陈沁; 阮菁如; 刘建明; 苏志寿

    2011-01-01

    目的 为了解思明区食品及外环境水体中霍乱弧菌的污染状况,为制订霍乱防控策略提供依据.方法根据2005-2010年《福建省霍乱监测方案》要求,对思明区食品及外环境水体开展霍乱弧菌监测.结果共采集各类标本4861份,检出霍乱弧菌78份,总阳性率1.60%.食品检测3517份,检出霍乱弧菌73份,阳性率2.08%,各类食品以蛙类阳性率(12.30%)最高,其次为甲壳类(2.69%)、鱼类(2.18%).水体检测1344份,检出霍乱弧茵5份,阳性率0.43%.检出的霍乱弧菌中,45例为01群稻叶型,33例为01群小川型,经霍乱毒素基因检测均为非产毒株.结论思明区水产品中的霍乱弧菌污染程度较高,应加强对蛙类食品的监测和管理.%Objective To investigate the contamination situation of Vibrio Cholera in foods and external environmental water bodies in Siming district, and provide scientific evidence for the prevention and control of cholera. Methods Foods and external environmental water bodies were monitored for Vibrio Cholera in Siming district according to the requirements of Cholera Surveillance Program In Fujian Province (2005 -2010). Results A total of 4 861 specimens of different types were collected, and 78 samples with Vibrio Cholera were detected. The total positive rate was 1. 60%. In which 3 517 foods were collected, and Vibrio Cholera were detected in 73 samples, with positive rate 2.08%. The highest positive rate was from frog species (12. 30% ) in food, fol-lowed by crustaceans (2. 69% ) , and fishes (2. 18% ); 1 344 water bodies were collected, and 5 samples with Vibrio Cholera were detected, with positive rate 0.43%. Among the detections, Vibrio Cholera in 45 samples were Inaba type and in 33 samples were Ogawa type, and all the bacterial strains were non - toxigenic strains according to the cholera toxin gene detection. Conclusion The contamination levels of Vibrio Cholera in the aquatic products are higher than expected, the

  5. Structure of the Minor Pseudopilin EpsH From the Type 2 Secretion System of Vibrio Cholerae

    Energy Technology Data Exchange (ETDEWEB)

    Yanez, M.E.; Korotkov, K.V.; Abendroth, J.; Hol, W.G.J.

    2009-05-28

    Many Gram-negative bacteria use the multi-protein type II secretion system (T2SS) to selectively translocate virulence factors from the periplasmic space into the extracellular environment. In Vibrio cholerae the T2SS is called the extracellular protein secretion (Eps) system, which translocates cholera toxin and several enzymes in their folded state across the outer membrane. Five proteins of the T2SS, the pseudopilins, are thought to assemble into a pseudopilus, which may control the outer membrane pore EpsD, and participate in the active export of proteins in a 'piston-like' manner. We report here the 2.0 {angstrom} resolution crystal structure of an N-terminally truncated variant of EpsH, a minor pseudopilin from Vibrio cholerae. While EpsH maintains an N-terminal {alpha}-helix and C-terminal {beta}-sheet consistent with the type 4a pilin fold, structural comparisons reveal major differences between the minor pseudopilin EpsH and the major pseudopilin GspG from Klebsiella oxytoca: EpsH contains a large {beta}-sheet in the variable domain, where GspG contains an {alpha}-helix. Most importantly, EpsH contains at its surface a hydrophobic crevice between its variable and conserved {beta}-sheets, wherein a majority of the conserved residues within the EpsH family are clustered. In a tentative model of a T2SS pseudopilus with EpsH at its tip, the conserved crevice faces away from the helix axis. This conserved surface region may be critical for interacting with other proteins from the T2SS machinery.

  6. Uptake of Vibrio cholerae Biotype eltor from Contaminated Water by Water Hyacinth (Eichornia crassipes)

    OpenAIRE

    Spira, William M.; Huq, Anwarul; Ahmed, Qazi Shafi; Saeed, Yusuf A.

    1981-01-01

    Vibrio cholerae biotype eltor appears to concentrate on the surface of the water hyacinth (Eichornia crassipes), thereby enhancing its survival and its potential for transmission through waterways of cholera-endemic regions such as Bangladesh.

  7. “Non-Toxic” Proteins of the Botulinum Toxin Complex Exert In-vivo Toxicity

    Science.gov (United States)

    Miyashita, Shin-Ichiro; Sagane, Yoshimasa; Suzuki, Tomonori; Matsumoto, Takashi; Niwa, Koichi; Watanabe, Toshihiro

    2016-01-01

    The botulinum neurotoxin (BoNT) causes muscle paralysis and is the most potent toxin in nature. BoNT is associated with a complex of auxiliary “Non-Toxic” proteins, which constitute a large-sized toxin complex (L-TC). However, here we report that the “Non-Toxic” complex of serotype D botulinum L-TC, when administered to rats, exerts in-vivo toxicity on small-intestinal villi. Moreover, Serotype C and D of the “Non-Toxic” complex, but not BoNT, induced vacuole-formation in a rat intestinal epithelial cell line (IEC-6), resulting in cell death. Our results suggest that the vacuole was formed in a manner distinct from the mechanism by which Helicobacter pylori vacuolating toxin (VacA) and Vibrio cholerae haemolysin induce vacuolation. We therefore hypothesise that the serotype C and D botulinum toxin complex is a functional hybrid of the neurotoxin and vacuolating toxin (VT) which arose from horizontal gene transfer from an ancestral BoNT-producing bacterium to a hypothetical VT-producing bacterium. PMID:27507612

  8. "Non-Toxic" Proteins of the Botulinum Toxin Complex Exert In-vivo Toxicity.

    Science.gov (United States)

    Miyashita, Shin-Ichiro; Sagane, Yoshimasa; Suzuki, Tomonori; Matsumoto, Takashi; Niwa, Koichi; Watanabe, Toshihiro

    2016-01-01

    The botulinum neurotoxin (BoNT) causes muscle paralysis and is the most potent toxin in nature. BoNT is associated with a complex of auxiliary "Non-Toxic" proteins, which constitute a large-sized toxin complex (L-TC). However, here we report that the "Non-Toxic" complex of serotype D botulinum L-TC, when administered to rats, exerts in-vivo toxicity on small-intestinal villi. Moreover, Serotype C and D of the "Non-Toxic" complex, but not BoNT, induced vacuole-formation in a rat intestinal epithelial cell line (IEC-6), resulting in cell death. Our results suggest that the vacuole was formed in a manner distinct from the mechanism by which Helicobacter pylori vacuolating toxin (VacA) and Vibrio cholerae haemolysin induce vacuolation. We therefore hypothesise that the serotype C and D botulinum toxin complex is a functional hybrid of the neurotoxin and vacuolating toxin (VT) which arose from horizontal gene transfer from an ancestral BoNT-producing bacterium to a hypothetical VT-producing bacterium. PMID:27507612

  9. Toxins Best Paper Award 2015

    OpenAIRE

    Tesh, Vernon L.

    2015-01-01

    In order to recognize outstanding papers related to biotoxins and toxinology that have been published in Toxins, the Editorial Board established an annual “Toxins Best Paper Award”. We are pleased to announce the first “Toxins Best Paper Award” for 2015. Nominations were selected by the Editorial Board members, with all papers published in 2011 eligible for consideration. Reviews and original research articles were evaluated separately. Following review and voting by the Toxins Best Paper Awa...

  10. Toxin plasmids of Clostridium perfringens.

    Science.gov (United States)

    Li, Jihong; Adams, Vicki; Bannam, Trudi L; Miyamoto, Kazuaki; Garcia, Jorge P; Uzal, Francisco A; Rood, Julian I; McClane, Bruce A

    2013-06-01

    In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

  11. 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.

  12. Cholera toxin B suppresses allergic inflammation through induction of secretory IgA

    NARCIS (Netherlands)

    H.H. Smits; A.K. Gloudemans; M. van Nimwegen; M.A. Willart; T. Soullié; F. Muskens; E.C. de Jong; L. Boon; C. Pilette; F.E. Johansen; H.C. Hoogsteden; H. Hammad; B.N. Lambrecht

    2009-01-01

    In healthy individuals, humoral immune responses to allergens consist of serum IgA and IgG4, whereas cellular immune responses are controlled by regulatory T (Treg) cells. In search of new compounds that might prevent the onset of allergies by stimulating this type of immune response, we have focuse

  13. Botulinum Toxin Therapy

    Science.gov (United States)

    ... resources Meet our partners Español Donate Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ... toxin therapy public SPOT Skin Cancer™ Diseases and treatments Acne and rosacea Bumps and growths Color problems Contagious skin diseases ...

  14. Toxins Best Paper Award 2015

    Directory of Open Access Journals (Sweden)

    Vernon L. Tesh

    2015-03-01

    Full Text Available In order to recognize outstanding papers related to biotoxins and toxinology that have been published in Toxins, the Editorial Board established an annual “Toxins Best Paper Award”. We are pleased to announce the first “Toxins Best Paper Award” for 2015. Nominations were selected by the Editorial Board members, with all papers published in 2011 eligible for consideration. Reviews and original research articles were evaluated separately. Following review and voting by the Toxins Best Paper Award Committee, the following three papers have won Toxins Best Paper Awards for 2015:[...

  15. 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

  16. CHOLERA IN BIDAR DISTRICT OF KARNATAKA STATE, INDIA

    Directory of Open Access Journals (Sweden)

    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

  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. Whole genome PCR scanning reveals the syntenic genome structure of toxigenic Vibrio cholerae strains in the O1/O139 population.

    Directory of Open Access Journals (Sweden)

    Bo Pang

    Full Text Available Vibrio cholerae is commonly found in estuarine water systems. Toxigenic O1 and O139 V. cholerae strains have caused cholera epidemics and pandemics, whereas the nontoxigenic strains within these serogroups only occasionally lead to disease. To understand the differences in the genome and clonality between the toxigenic and nontoxigenic strains of V. cholerae serogroups O1 and O139, we employed a whole genome PCR scanning (WGPScanning method, an rrn operon-mediated fragment rearrangement analysis and comparative genomic hybridization (CGH to analyze the genome structure of different strains. WGPScanning in conjunction with CGH revealed that the genomic contents of the toxigenic strains were conservative, except for a few indels located mainly in mobile elements. Minor nucleotide variation in orthologous genes appeared to be the major difference between the toxigenic strains. rrn operon-mediated rearrangements were infrequent in El Tor toxigenic strains tested using I-CeuI digested pulsed-field gel electrophoresis (PFGE analysis and PCR analysis based on flanking sequence of rrn operons. Using these methods, we found that the genomic structures of toxigenic El Tor and O139 strains were syntenic. The nontoxigenic strains exhibited more extensive sequence variations, but toxin coregulated pilus positive (TCP+ strains had a similar structure. TCP+ nontoxigenic strains could be subdivided into multiple lineages according to the TCP type, suggesting the existence of complex intermediates in the evolution of toxigenic strains. The data indicate that toxigenic O1 El Tor and O139 strains were derived from a single lineage of intermediates from complex clones in the environment. The nontoxigenic strains with non-El Tor type TCP may yet evolve into new epidemic clones after attaining toxigenic attributes.

  19. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  20. Characterization of Undermethylated Sites in Vibrio cholerae

    Science.gov (United States)

    Dalia, Ankur B.; Lazinski, David W.

    2013-01-01

    The activities of DNA methyltransferases are important for a variety of cellular functions in bacteria. In this study, we developed a modified high-throughput technique called methyl homopolymer tail mediated sequencing (methyl HTM-seq) to identify the undermethylated sites in the Vibrio cholerae genome for the two DNA methyltransferases, Dam, an adenine methyltransferase, and VchM, a cytosine methyltransferase, during growth in rich medium in vitro. Many of the undermethylated sites occurred in intergenic regions, and for most of these sites, we identified the transcription factors responsible for undermethylation. This confirmed the presence of previously hypothesized DNA-protein interactions for these transcription factors and provided insight into the biological state of these cells during growth in vitro. DNA adenine methylation has previously been shown to mediate heritable epigenetic switches in gene regulation. However, none of the undermethylated Dam sites tested showed evidence of regulation by this mechanism. This study is the first to identify undermethylated adenines and cytosines genomewide in a bacterium using second-generation sequencing technology. PMID:23504020

  1. Cholera outbreak in Tumpat, Kelantan-1990.

    Science.gov (United States)

    Isa, A R; Othman, W M; Ishak, A

    1990-09-01

    Two episodes of El Tor cholera outbreak occurred in Tumpat, Kelantan between the 13th of January and the 16th of May 1990. Every case and carrier reported were investigated to determine the source and mode of transmission and to identify specific preventive measures to break the chain of transmission. There were 109 cases and 85 carriers involved in this study. The first episode of one case only was of Inaba serotype while the second episode was caused by the imported Ogawa serotype. Two foci of spread were identified from cluster occurrence but the majority of infection had no discernible link between them. The outbreak became both explosive and protracted indicating poor basic sanitation and personal hygiene. Person-to-person transmission via food and water was the main mode of spread. The Kelantan river water and river clams were confirmed sources of reservoir during the outbreak. Recommendations for prevention are intensified surveillance throughout the year,urgent upgrading of potable water supply and concerted effort in public health education especially against the use of river water and the consumption of raw food. PMID:2152079

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Mortality Rates during Cholera Epidemic, Haiti, 2010-2011.

    Science.gov (United States)

    Luquero, Francisco J; Rondy, Marc; Boncy, Jacques; Munger, André; Mekaoui, Helmi; Rymshaw, Ellen; Page, Anne-Laure; Toure, Brahima; Degail, Marie Amelie; Nicolas, Sarala; Grandesso, Francesco; Ginsbourger, Maud; Polonsky, Jonathan; Alberti, Kathryn P; Terzian, Mego; Olson, David; Porten, Klaudia; Ciglenecki, Iza

    2016-03-01

    The 2010 cholera epidemic in Haiti was one of the largest cholera epidemics ever recorded. To estimate the magnitude of the death toll during the first wave of the epidemic, we retrospectively conducted surveys at 4 sites in the northern part of Haiti. Overall, 70,903 participants were included; at all sites, the crude mortality rates (19.1-35.4 deaths/1,000 person-years) were higher than the expected baseline mortality rate for Haiti (9 deaths/1,000 person-years). This finding represents an excess of 3,406 deaths (2.9-fold increase) for the 4.4% of the Haiti population covered by these surveys, suggesting a substantially higher cholera mortality rate than previously reported. PMID:26886511

  4. What is cholera? A preliminary study on caretakers knowledge in Bangladesh

    DEFF Research Database (Denmark)

    Tamason, Charlotte Crim; Tulsiani, Suhella; Amin Hoque, Bilqis;

    2016-01-01

    Abstract Background: Cholera has afflicted the Indian sub-continent for centuries, predominantly in West Bengal and modern-day Bangladesh. This preliminary study aims to understand the current level of knowledge of cholera in female Bangladeshi caretakers, which is important in the outcome of the...... disease and its spread. A pilot study was conducted among 85 women in Bangladesh using qualitative questionnaires to explore the ability of female caretakers in identifying cholera and its transmission. Findings: The survey revealed that though all the female caretakers were aware of the term “cholera....... Keywords: Bangladesh, Cholera, Diarrhea, Qualitative research, Social stigma...

  5. 多重荧光定量PCR甄别霍乱弧菌方法的建立%Development of multiplex real time PCR methodology for better identification and discrimination of Vibrio cholerae and O139 serotype

    Institute of Scientific and Technical Information of China (English)

    张政; 金大智; 朱水荣; 叶菊莲; 罗芸

    2010-01-01

    Objective To develop a rapid, sensitive and specific assay method, based on multiplex real time PCR for identifying Vibrio cholerae and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae. Methods Cholera toxin A subunit gene (ctxA) and glycosyltransferase gene (LPSgt) were chosen as targets according to Vibrio cholerae and Vibrio cholerae O139 serotype,and then the primers and TaqMan-MGB probe were designed. The 5'end of probes was labeled with FAM and VIC fluoresceins respectively while the 3' end of probes was labeled with MGB. The PCR reaction was optimized systematically. Then the specificity, sensitivity and reproducibility of multiplex real time PCR were estimated. Finally, multiplex real time PCR was applied to detect the clinical specimens. Results Vibrio cholerae was identified by multiplex real time PCR accurately and quickly,which could distinguish Vibrio cholerae O139 serotype from Vibrio cholerae. Vibrio cholerae was identified positive for primer pairs and probes from ctxA gene, and Vibrio cholerae O139 serotype tested was positive for LPSgt gene. Meanwhile, none of other bacteria was identified. Sensitivity of the test was 2 × 102 cfu/ml. When this assay was applied directly to identify 45 clinical specimens, results showed that 10 were positive to Vibrio cholerae, in which 4 clinical specimens were positive to Vibrio cholerae O139 serotype. All the results were the same to the one that had been obtained from the conventional assays. Conclusion Our rsults showed that the multiplex real time PCR was a reliable,accurate and feasible method for identifying Vibrio cholerae that carrying toxin gene and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae. This method could be applied to the cholera surveillance, prevention and control system for identifying and distinguishing Vibrio cholerae in the labs.%目的 利用多重荧光定量PCR技术,建立一种快速、准确、特异甄别霍乱弧菌的定量方法.方法 分

  6. Cholera in metropolitan Manila: foodborne transmission via street vendors.

    OpenAIRE

    Lim-Quizon, M. C.; Benabaye, R. M.; White, F M; Dayrit, M. M.; White, M E

    1994-01-01

    Reported are the results of an unmatched case-control study to determine the risk factors associated with acquisition of cholera in Manila. Cases were patients admitted to the San Lazaro Hospital between July and September 1989 and whose stools yielded Vibrio cholerae O1 on culture. Controls were patients admitted to the same hospital and who had no history of diarrhoea or of having taken antibiotics during the 3 days prior to admission. Of the 158 cases and 158 controls who had bought food f...

  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. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2011-05-08

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17β-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17β-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17β-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective permeabilization of apical or basolateral membranes with amphotericin B or nystatin was used to isolate basolateral K(+) channel and apical Cl(-) channel activity, respectively. 17β-Estradiol dose-dependently inhibited secretory responses to both toxins with IC(50) values of approximately 1nM. This effect was female-gender specific, with no inhibition observed in male tissues. 17β-Estradiol responses were insensitive to the pure anti-estrogen ICI 182,720. 17β-Estradiol exerted its effects downstream of enterotoxin-induced production of second messengers (cAMP and cGMP) but was dependent on PKCδ activation. In nystatin-permeabilized tissues, apical Cl(-) currents were unaffected by 17β-estradiol treatment while basolateral K(+) current was profoundly inhibited by the hormone. This current was sensitive to the specific KCNQ1 channel inhibitors chromanol 293B and HMR-1556. In conclusion, 17β-estradiol inhibits enterotoxin-induced Cl(-) secretion via a PKCδ-dependent mechanism involving inhibition of basolateral KCNQ1 channels. These data elucidate mechanisms of 17β-estradiol inhibition of Cl(-) secretion induced by enterotoxins in intestinal epithelia, which may be relevant for the treatment of diarrheal diseases.

  10. Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2012-02-01

    Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17beta-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17beta-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17beta-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective permeabilization of apical or basolateral membranes with amphotericin B or nystatin was used to isolate basolateral K(+) channel and apical Cl(-) channel activity, respectively. 17beta-Estradiol dose-dependently inhibited secretory responses to both toxins with IC(50) values of approximately 1nM. This effect was female-gender specific, with no inhibition observed in male tissues. 17beta-Estradiol responses were insensitive to the pure anti-estrogen ICI 182,720. 17beta-Estradiol exerted its effects downstream of enterotoxin-induced production of second messengers (cAMP and cGMP) but was dependent on PKCdelta activation. In nystatin-permeabilized tissues, apical Cl(-) currents were unaffected by 17beta-estradiol treatment while basolateral K(+) current was profoundly inhibited by the hormone. This current was sensitive to the specific KCNQ1 channel inhibitors chromanol 293B and HMR-1556. In conclusion, 17beta-estradiol inhibits enterotoxin-induced Cl(-) secretion via a PKCdelta-dependent mechanism involving inhibition of basolateral KCNQ1 channels. These data elucidate mechanisms of 17beta-estradiol inhibition of Cl(-) secretion induced by enterotoxins in intestinal epithelia, which may be relevant for the treatment of diarrheal diseases.

  11. Toxins and drug discovery.

    Science.gov (United States)

    Harvey, Alan L

    2014-12-15

    Components from venoms have stimulated many drug discovery projects, with some notable successes. These are briefly reviewed, from captopril to ziconotide. However, there have been many more disappointments on the road from toxin discovery to approval of a new medicine. Drug discovery and development is an inherently risky business, and the main causes of failure during development programmes are outlined in order to highlight steps that might be taken to increase the chances of success with toxin-based drug discovery. These include having a clear focus on unmet therapeutic needs, concentrating on targets that are well-validated in terms of their relevance to the disease in question, making use of phenotypic screening rather than molecular-based assays, and working with development partners with the resources required for the long and expensive development process. PMID:25448391

  12. 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

  13. PAR-1 mediated apoptosis of breast cancer cells by V. cholerae hemagglutinin protease.

    Science.gov (United States)

    Ray, Tanusree; Pal, Amit

    2016-05-01

    Bacterial toxins have emerged as promising agents in cancer treatment strategy. Hemagglutinin (HAP) protease secreted by Vibrio cholerae induced apoptosis in breast cancer cells and regresses tumor growth in mice model. The success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity for normal tissues. Increased expression of Protease Activated Receptor-1 (PAR-1) has been reported in different malignant cells. In this study we report that HAP induced activation and over expression of PAR-1 in breast cancer cells (EAC). Immunoprecipitation studies have shown that HAP specifically binds with PAR-1. HAP mediated activation of PAR-1 caused nuclear translocation of p50-p65 and the phosphorylation of p38 which triggered the activation of NFκB and MAP kinase signaling pathways. These signaling pathways enhanced the cellular ROS level in malignant cells that induced the intrinsic pathway of cell apoptosis. PAR-1 mediated apoptosis by HAP of malignant breast cells without effecting normal healthy cells in the same environment makes it a good therapeutic agent for treatment of cancer. PMID:26897170

  14. Development of an ELISA kit using monoclonal antibody to Clostridium difficile toxin A

    Institute of Scientific and Technical Information of China (English)

    Si-Wu Fu; Ya-Li Zhang; Dian-Yuan Zhou

    2004-01-01

    AIM: To establish an ELISA kit using monoclonal antibodiesagainst Clostridium difficile ( C. difficile) toxin A.METHODS: An indirect sandwich ElISA was described using the purified rabbit monospecific antiserum as capturing antibody. After the polystyrene microtitre plates with 96 fiat-bottomed wells were coated with rabbit antiserum, the wells were blocked with 100 g/L BSA in PBS-T. C. difficiletoxin A or culture filtrates were added to each well and then monoclonal antibodies IgG-horseradish peroxidase conjugate was added as detecting antibody, tetramethylbenzidine was used as substrate and A450 of the stopped reacting product was recorded in an automated plate reader. RESULTS: The tested specimens included culture filtrates of 2 strains of toxigenic C. difficile, 2 strains of non-toxigenic C. difficile, 26 strains of E. coli, 2 strains of S. dysenteriae, 1 strain of Bif infantis, 5 strains of V. cholera, 2 strains ofS. typhi, 7 strains of C. botulinum, 1 strain of toxigenic C. sordllii, and 1 strain of C. butyricum. A total of 47 strains of culture filtrates were all negative except for 2 strains of toxigenic C. difficile. The detective limitation of toxin A was 0.1 ng/mL.CONCLUSION: An ELISA kit with high specificity and excellent sensitivity for the rapid detection of C. difficile toxin A was established. It will be a useful tool for diagnostic test of C. difficile toxin A.

  15. Photolabelling of mutant forms of the S1 subunit of pertussis toxin with NAD+.

    Science.gov (United States)

    Cieplak, W; Locht, C; Mar, V L; Burnette, W N; Keith, J M

    1990-01-01

    The S1 subunit of pertussis toxin catalyses the hydrolysis of NAD+ (NAD+ glycohydrolysis) and the NAD(+)-dependent ADP-ribosylation of guanine-nucleotide-binding proteins. Recently, the S1 subunit of pertussis toxin was shown to be photolabelled by using radiolabelled NAD+ and u.v.; the primary labelled residue was Glu-129, thereby implicating this residue in the binding of NAD+. Studies from various laboratories have shown that the N-terminal portion of the S1 subunit, which shows sequence similarity to cholera toxin and Escherichia coli heat-labile toxin, is important to the maintenance of both glycohydrolase and transferase activity. In the present study the photolabelling technique was applied to the analysis of a series of recombinant-derived S1 molecules that possessed deletions or substitutions near the N-terminus of the S1 molecule. The results revealed a positive correlation between the extent of photolabelling with NAD+ and the magnitude of specific NAD+ glycohydrolase activity exhibited by the mutants. Enzyme kinetic analyses of the N-terminal mutants also identified a mutant with substantially reduced activity, a depressed photolabelling efficiency and a markedly increased Km for NAD+. The results support a direct role for the N-terminal region of the S1 subunit in the binding of NAD+, thereby providing a rationale for the effect of mutations in this region on enzymic activity. Images Fig. 1. PMID:2363691

  16. Clostridium difficile binary toxin CDT

    OpenAIRE

    Gerding, Dale N.; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

    2013-01-01

    Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylatio...

  17. 霍乱弧菌及肠出血性大肠杆菌多重PCR检测方法的建立%Development of multiplex PCR for detection of Vibrio cholerae and enterohemorrhagic Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    刘彦晶; 吴大成; 孟福强; 袁洁; 孙洋; 冯书章

    2012-01-01

    A multiplex PCR method was developed for the rapid detection of genes encoding Shiga toxins 1 and 2(stx1 and stx2) of enterohemorrhagic Escherichia coli(EHEC) and Cholera toxin gene(ctx) of Vibrio cholerae.Three pairs of primers were synthesized.The size of amplified products is different,so it is easy to distinguish the bands on agarose gel.The method includes enrichment before the PCR reaction.The specificity of the multiplex PCR method was determined by using 25 strains of pure-cultured bacteria,including Vibrio cholerae O1 and O139 and 4 EHEC strains.All 6 EHEC strains and Vibrio cholerae strains produced positive bands,whereas the others did not.The sensitivity was evaluated by detection of artificially contaminated samples,with a range of 100-1 000 CFU/mL in contaminated water samples and 1 CFU/mL after enrichment.These results indicated that the Multi-PCR method exhibited high specificity and sensitivity in the detection of EHEC and Vibrio cholerae.It could be used to detec environment samples contaminated by EHEC and Vibrio cholerae.%针对霍乱弧菌肠毒素和肠出血性大肠杆菌志贺毒素基因(ctx、stx1和stx2)设计引物,扩增大小不同的特异性片段,优化反应条件,建立多重PCR方法,对人工污染的水样品进行模拟检测。结果显示,多重PCR扩增系统针对目的菌具有高度的特异性。敏感性试验证实,当多重PCR反应体系中模板含量在10CFU时仍能检出。模拟水样品多重PCR检测的敏感性试验证明,人工污染的河水直接集菌检测敏感性为100~1 000CFU/mL,增菌培养后多重PCR检测敏感性可达1CFU/mL。本试验于同一PCR体系检测霍乱弧菌和肠出血性大肠杆菌的毒素基因,可用于这2种致腹泻性病原菌的快速检测。

  18. 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.

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

    Science.gov (United States)

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

    1994-01-01

    Natural products of several plants, according to the geographic location, are used by Peruvian people in the popular treatment of diarrhea, with good success. When cholerae cases appeared in Peru, we were interested to know the "in vitro" effect against Vibrio cholerae 01, of these useful plants to treat diarrhea. The following plants were tested: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Punica granatum, Malus sativa, Cydonia oblonga, Chenopodium ambrosoides, Krameria triandria, Tea chinensis, Daucus carota, Persea gratissima, Psidium guayaba and Lippia dulcis. Decoction or infusion of the plants were used in the "in vitro" experiments. The following plants showed no "in vitro" effect against V. cholerae: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Chenopodium ambrosoides, Krameria triandria, Psidium guayaba, Lippia dulcis and Daucus carota. Decoction of Malus sativa and Cydenia oblonga showed bactericidal effect for their acidity and stone avocado (Persea gratissima) a late bactericidal effect. Tea infusión and the decoction of Punica granatum peel, showed the best bactericidal effect and we suggest to use them as to stop cholera spreading. PMID:8018898

  20. 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.

  1. 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-

  2. 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

  3. Requirements for anthrax toxin entry into cells

    OpenAIRE

    Ryan, Patricia Lynn

    2010-01-01

    Bacillus anthracis secretes a harmful exotoxin called anthrax toxin. Anthrax toxin has deleterious effects on several host cell types and is a significant contributor to anthrax pathogenesis. Toxin-deleted strains of B. anthracis are highly attenuated and many of the symptoms of anthrax can be replicated with anthrax toxin alone. Anthrax toxin is an AB-type toxin with two catalytic A moieties. PA, the B moiety, is responsible for receptor binding, pore formation and translocation of the catal...

  4. Shiga Toxin Detection Methods : A Short Review

    OpenAIRE

    Guerrero, Y. Castaño; González-Aguilar, G.

    2013-01-01

    The Shiga toxins comprise a family of related protein toxins secreted by certain types of bacteria. Shigella dysenteriae, some strain of Escherichia coli and other bacterias can express toxins which caused serious complication during the infection. Shiga toxin and the closely related Shiga-like toxins represent a group of very similar cytotoxins that may play an important role in diarrheal disease and hemolytic-uremic syndrome. The outbreaks caused by this toxin raised serious public health c...

  5. Lymphocyte receptors for pertussis toxin

    International Nuclear Information System (INIS)

    We have investigated human T-lymphocyte receptors for pertussis toxin by affinity isolation and photoaffinity labeling procedures. T lymphocytes were obtained from peripheral human blood, surface iodinated, and solubilized in Triton X-100. The iodinated mixture was then passed through pertussis toxin-agarose, and the fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography of the fixed, dried gels revealed several bands in the pertussis toxin-bound fraction that were not observed in fractions obtained from histone or fetuin-agarose. Further investigations employed a photoaffinity labeling reagent, sulfosuccinimidyl 2-(p-azido-salicylamido)-1,3'-dithiopropionate, to identify pertussis toxin receptors in freshly isolated peripheral blood monocytic cells, T lymphocytes, and Jurkat cells. In all three cell systems, the pertussis toxin affinity probe specifically labeled a single protein species with an apparent molecular weight of 70,000 that was not observed when the procedure was performed in the presence of excess unmodified pertussis toxin. A protein comparable in molecular weight to the one detected by the photoaffinity labeling technique was also observed among the species that bound to pertussis toxin-agarose. The results suggest that pertussis toxin may bind to a 70,000-Da receptor in human T lymphocytes

  6. Toxin-Based Therapeutic Approaches

    Directory of Open Access Journals (Sweden)

    Itai Benhar

    2010-10-01

    Full Text Available Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmaceutical potential of such toxins when they are used to efficiently impair essential cellular processes and/or damage the integrity of their target cells. The following review summarizes major advances in the field of toxin based therapeutics and offers a comprehensive description of the mode of action of each applied toxin.

  7. Engineered bacterial communication prevents Vibrio cholerae virulence in an infant mouse model

    OpenAIRE

    Duan, Faping; March, John C.

    2010-01-01

    To investigate the possibility of using commensal bacteria as signal mediators for inhibiting the disease cholera, we stably transformed Escherichia coli Nissle 1917 (Nissle) to express the autoinducer molecule cholera autoinducer 1 (CAI-1) (shown previously to prevent virulence when present with another signaling molecule, autoinducer 2, at high concentrations) and determined the effect on Vibrio cholerae virulence gene expression and colonization in an infant mouse model. We found that pret...

  8. 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.

  9. Local perceptions of cholera and anticipated vaccine acceptance in Katanga province, Democratic Republic of Congo

    OpenAIRE

    Merten, Sonja; Schaetti, Christian; Manianga, Cele; Lapika, Bruno; Chaignat, Claire-Lise; Hutubessy, Raymond; Weiss, Mitchell G

    2013-01-01

    Background In regions where access to clean water and the provision of a sanitary infrastructure has not been sustainable, cholera continues to pose an important public health burden. Although oral cholera vaccines (OCV) are effective means to complement classical cholera control efforts, still relatively little is known about their acceptability in targeted communities. Clarification of vaccine acceptability prior to the introduction of a new vaccine provides important information for future...

  10. 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...

  11. 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...

  12. 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 ...

  13. 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.

  14. 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

  15. 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...

  16. 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.

  17. "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

  18. 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...

  19. [Shiga toxin and tetanus toxin as a potential biologic weapon].

    Science.gov (United States)

    Toczyska, Izabela; Płusa, Tadeusz

    2015-09-01

    Toxins produced by the bacteria are of particular interest as potential cargo combat possible for use in a terrorist attack or war. Shiga toxin is usually produced by shiga toxigenic strains of Escherichia coli (STEC - shigatoxigenic Escherichia coli). To infection occurs mostly after eating contaminated beef. Clinical syndromes associated with Shiga toxin diarrhea, hemorrhagic colitis, hemolytic uremic syndrome (HUS - hemolytic uremic syndrome) or thrombotic thrombocytopenic purpura. Treatment is symptomatic. In HUS, in which mortality during an epidemic reaches 20%, extending the kidney injury dialysis may be necessary. Exposure to tetanus toxin produced by Clostridium tetani, resulting in the most generalized tetanus, characterized by increased muscle tension and painful contractions of individual muscle groups. In the treatment beyond symptomatic behavior (among others spasticity medications, anticonvulsants, muscle relaxants) is used tetanus antitoxin and antibiotics (metronidazole choice). A common complication is acute respiratory failure - then it is necessary to implement mechanical ventilation. PMID:26449578

  20. Management of multipartite genomes: the Vibrio cholerae model.

    Science.gov (United States)

    Val, Marie-Eve; Soler-Bistué, Alfonso; Bland, Michael J; Mazel, Didier

    2014-12-01

    A minority of bacterial species has been found to carry a genome divided among several chromosomes. Among these, all Vibrio species harbor a genome split into two chromosomes of uneven size, with distinctive replication origins whose replication firing involves common and specific factors. Most of our current knowledge on replication and segregation in multi-chromosome bacteria has come from the study of Vibrio cholerae, which is now the model organism for this field. It has been firmly established that replication of the two V. cholerae chromosomes is temporally regulated and coupled to the cell cycle, but the mediators of these processes are as yet mostly unknown. The two chromosomes are also organized along different patterns within the cell and occupy different subcellular domains. The selective advantages provided by this partitioning into two replicons are still unclear and are a key motivation for these studies. PMID:25460805

  1. An Entamoeba histolytica ADP-ribosyl transferase from the diphtheria toxin family modifies the bacterial elongation factor Tu.

    Science.gov (United States)

    Avila, Eva E; Rodriguez, Orlando I; Marquez, Jaqueline A; Berghuis, Albert M

    2016-06-01

    ADP-ribosyl transferases are enzymes involved in the post-translational modification of proteins; they participate in multiple physiological processes, pathogenesis and host-pathogen interactions. Several reports have characterized the functions of these enzymes in viruses, prokaryotes and higher eukaryotes, but few studies have reported ADP-ribosyl transferases in lower eukaryotes, such as parasites. The locus EHI_155600 from Entamoeba histolytica encodes a hypothetical protein that possesses a domain from the ADP-ribosylation superfamily; this protein belongs to the diphtheria toxin family according to a homology model using poly-ADP-ribosyl polymerase 12 (PARP12 or ARTD12) as a template. The recombinant protein expressed in Escherichia coli exhibited in vitro ADP-ribosylation activity that was dependent on the time and temperature. Unlabeled βNAD(+), but not ADP-ribose, competed in the enzymatic reaction using biotin-βNAD(+) as the ADP-ribose donor. The recombinant enzyme, denominated EhToxin-like, auto-ADP-ribosylated and modified an acceptor from E. coli that was identified by MS/MS as the elongation factor Tu (EF-Tu). To the best of our knowledge, this is the first report to identify an ADP-ribosyl transferase from the diphtheria toxin family in a protozoan parasite. The known toxins from this family (i.e., the diphtheria toxin, the Pseudomonas aeruginosa toxin Exo-A, and Cholix from Vibrio cholerae) modify eukaryotic elongation factor two (eEF-2), whereas the amoeba EhToxin-like modified EF-Tu, which is another elongation factor involved in protein synthesis in bacteria and mitochondria. PMID:27234208

  2. Detection of extracellular toxin(s) produced by Vibrio vulnificus.

    OpenAIRE

    Kreger, A; Lockwood, D.

    1981-01-01

    Conditions are described for the production, in high titers, a heat-labile, antigenic, extracellular toxin(s) by Vibrio vulnificus, a recently recognized human pathogen. Bacteriologically sterile culture filtrate preparations obtained from mid-logarithmic-phase cultures of the bacterium possessed cytolytic activity against mammalian erythrocytes, cytotoxic activity for Chinese hamster ovary cells, vascular permeability factor activity in guinea pig skin, and lethal activity for mice. The spec...

  3. From Cholera to Burns: A Role for Oral Rehydration Therapy

    OpenAIRE

    Milner, S. M.; Green, W.B.; Asuku, M.E.; M. Feldman; Makam, R.; Noppenberger, D; Price, L A; Prosciak, M.; van Loon, I.N.

    2011-01-01

    According to the practice guidelines of the American Burn Association on burn shock resuscitation, intravenous (IV) fluid therapy is the standard of care for the replacement of fluid and electrolyte losses in burn injury of ≥20% of the total body surface area. However, in mass burn casualties, IV fluid resuscitation may be delayed or unavailable. Oral rehydration therapy (ORT), which has been shown to be highly effective in the treatment of dehydration in epidemics of cholera, could be an alt...

  4. 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.

  5. Antimicrobial Resistance Patterns of Isolated Vibrio cholerae Strains

    Directory of Open Access Journals (Sweden)

    Hajia

    2016-02-01

    Full Text Available Background Cholera is a potentially life-threatening acute diarrheal disease caused by the toxigenic bacteria, Vibrio cholerae. Antibiotics should be selected using local antibiotic susceptibility testing patterns. Objectives This study was performed to identify the patterns of antimicrobial resistance in isolates collected from laboratory-confirmed cases of cholera during three years, from 2011 to 2013. Materials and Methods All isolates at the Health Reference Laboratory were tested by the Minimum Inhibitory Concentration (MIC Test using Liofilchem against ciprofloxacin, nalidixic acid, cefixime, ampicillin, tetracycline, trimethoprim-sulfamethoxazole, and erythromycin. The following organisms were used as quality control strains for MIC E-testing; Escherichia coli (ATCC 25922, Staphylococcus aureus (ATCC 29213, and Pseudomonas aeruginosa (ATCC 27853. Results Results of susceptibility testing showed complete sensitivity to ciprofloxacin, cefixime and amplicillin for both isolated Inaba and Ogawa serotypes except all isolated Inaba serotypes from year 2011, which were resistant to cefixime. These resistant Inaba serotypes were not isolated in the next year. Inaba serotypes showed an increased resistance rate of up to 100% to nalidixic acid, tetracycline and trimethoprim-sulfamethaxazone, while Ogawa serotypes were 100% sensitive at the end of year 2013. The susceptibility pattern of erytromycine was similar in these two types. Sensitivity to erythromycin was decreased in both Inaba and Ogawa serotypes. Conclusions The analyzed results indicate that tetracycline should not be considered as a first line antibiotic therapy for patients infected with Ogawa serotypes. Also, national guidelines for confirmation of cholera should be improved by responsible authorities to cover new resistance during outbreaks.

  6. Epsilon toxin: a fascinating pore-forming toxin.

    Science.gov (United States)

    Popoff, Michel R

    2011-12-01

    Epsilon toxin (ETX) is produced by strains of Clostridium perfringens classified as type B or type D. ETX belongs to the heptameric β-pore-forming toxins including aerolysin and Clostridium septicum alpha toxin, which are characterized by the formation of a pore through the plasma membrane of eukaryotic cells consisting in a β-barrel of 14 amphipatic β strands. By contrast to aerolysin and C. septicum alpha toxin, ETX is a much more potent toxin and is responsible for enterotoxemia in animals, mainly sheep. ETX induces perivascular edema in various tissues and accumulates in particular in the kidneys and brain, where it causes edema and necrotic lesions. ETX is able to pass through the blood-brain barrier and stimulate the release of glutamate, which accounts for the symptoms of nervous excitation observed in animal enterotoxemia. At the cellular level, ETX causes rapid swelling followed by cell death involving necrosis. The precise mode of action of ETX remains to be determined. ETX is a powerful toxin, however, it also represents a unique tool with which to vehicle drugs into the central nervous system or target glutamatergic neurons. PMID:21535407

  7. 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.

  8. 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...

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

    OpenAIRE

    Lewnard, Joseph A.; Antillón, Marina; Gonsalves, Gregg; Alice M Miller; Ko, Albert I; Virginia E Pitzer

    2016-01-01

    Background 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 or...

  10. 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...

  11. 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

  12. Toxin-Based Therapeutic Approaches

    OpenAIRE

    Itai Benhar; Assaf Shapira

    2010-01-01

    Protein toxins confer a defense against predation/grazing or a superior pathogenic competence upon the producing organism. Such toxins have been perfected through evolution in poisonous animals/plants and pathogenic bacteria. Over the past five decades, a lot of effort has been invested in studying their mechanism of action, the way they contribute to pathogenicity and in the development of antidotes that neutralize their action. In parallel, many research groups turned to explore the pharmac...

  13. 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.

  14. 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.

  15. Household-Level Spatiotemporal Patterns of Incidence of Cholera, Haiti, 2011

    OpenAIRE

    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

    2014-01-01

    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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Travel Health Alert Notices and Haiti Cholera Outbreak, Florida, USA, 2011

    OpenAIRE

    Selent, Monica U.; McWhorter, Amanda; De Rochars, Valery M. Beau; Myers, Rebecca; Hunter, David W.; Brown, Clive M.; Cohen, Nicole J.; Molinari, Noelle A.; Warwar, Kirsten; Robbins, Danisha; Heiman, Katherine E.; Newton, Anna E.; Schmitz, Ann; Oraze, Michael J.; Marano, Nina

    2011-01-01

    To enhance the timeliness of medical evaluation for cholera-like illness during the 2011 cholera outbreak in Hispaniola, printed Travel Health Alert Notices (T-HANs) were distributed to travelers from Haiti to the United States. Evaluation of the T-HANs’ influence on travelers’ health care–seeking behavior suggested T-HANs might positively influence health care–seeking behavior.

  3. [Toxins of Clostridium perfringens].

    Science.gov (United States)

    Morris, W E; Fernández-Miyakawa, M E

    2009-01-01

    Clostridium perfringens is an anaerobic gram-positive spore-forming bacillus. It is one of the pathogens with larger distribution in the environment; it can be isolated from soil and water samples, which also belongs to the intestinal flora of animals and humans. However, on some occasions it can act as an opportunistic pathogen, causing diseases such as gas gangrene, enterotoxemia in sheep and goats and lamb dysentery, among others. In human beings, it is associated to diseases such as food poisoning, necrotic enterocolitis of the infant and necrotic enteritis or pigbel in Papua-New Guinea tribes. The renewed interest existing nowadays in the study of C. perfringens as a veterinarian and human pathogen, together with the advance of molecular biology, had enabled science to have deeper knowledge of the biology and pathology of these bacteria. In this review, we discuss and update the principal aspects of C. perfringens intestinal pathology, in terms of the toxins with major medical relevance at present. PMID:20085190

  4. Targeted Toxins in Brain Tumor Therapy

    Directory of Open Access Journals (Sweden)

    Walter A. Hall

    2010-11-01

    Full Text Available Targeted toxins, also known as immunotoxins or cytotoxins, are recombinant molecules that specifically bind to cell surface receptors that are overexpressed in cancer and the toxin component kills the cell. These recombinant proteins consist of a specific antibody or ligand coupled to a protein toxin. The targeted toxins bind to a surface antigen or receptor overexpressed in tumors, such as the epidermal growth factor receptor or interleukin-13 receptor. The toxin part of the molecule in all clinically used toxins is modified from bacterial or plant toxins, fused to an antibody or carrier ligand. Targeted toxins are very effective against cancer cells resistant to radiation and chemotherapy. They are far more potent than any known chemotherapy drug. Targeted toxins have shown an acceptable profile of toxicity and safety in early clinical studies and have demonstrated evidence of a tumor response. Currently, clinical trials with some targeted toxins are complete and the final results are pending. This review summarizes the characteristics of targeted toxins and the key findings of the important clinical studies with targeted toxins in malignant brain tumor patients. Obstacles to successful treatment of malignant brain tumors include poor penetration into tumor masses, the immune response to the toxin component and cancer heterogeneity. Strategies to overcome these limitations are being pursued in the current generation of targeted toxins.

  5. 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 (γ01 = −0.147, p = 0.041) and a higher probability of reporting no cholera cases (α01 = 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 SES

  6. 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.

  7. 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.

  8. 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....... Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. our data show that biofilms are the protective agent enabling V. cholerae to...... survive protozoan grazing while their planktonic counterparts are eliminated. Grazing on planktonic V. cholerae was found to select for the biofilm-enhancing rugose phase variant, which is adapted to the surf ace-associated niche by the production of exopolymers. Interestingly, grazing resistance in V...

  9. 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.

  10. 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

  11. Scorpion toxins prefer salt solutions.

    Science.gov (United States)

    Nikouee, Azadeh; Khabiri, Morteza; Cwiklik, Lukasz

    2015-11-01

    There is a wide variety of ion channel types with various types of blockers, making research in this field very complicated. To reduce this complexity, it is essential to study ion channels and their blockers independently. Scorpion toxins, a major class of blockers, are charged short peptides with high affinities for potassium channels. Their high selectivity and inhibitory properties make them an important pharmacological tool for treating autoimmune or nervous system disorders. Scorpion toxins typically have highly charged surfaces and-like other proteins-an intrinsic ability to bind ions (Friedman J Phys Chem B 115(29):9213-9223, 1996; Baldwin Biophys J 71(4):2056-2063, 1996; Vrbka et al. Proc Natl Acad Sci USA 103(42):15440-15444, 2006a; Vrbka et al. J Phys Chem B 110(13):7036-43, 2006b). Thus, their effects on potassium channels are usually investigated in various ionic solutions. In this work, computer simulations of protein structures were performed to analyze the structural properties of the key residues (i.e., those that are presumably involved in contact with the surfaces of the ion channels) of 12 scorpion toxins. The presence of the two most physiologically abundant cations, Na(+) and K(+), was considered. The results indicated that the ion-binding properties of the toxin residues vary. Overall, all of the investigated toxins had more stable structures in ionic solutions than in water. We found that both the number and length of elements in the secondary structure varied depending on the ionic solution used (i.e., in the presence of NaCl or KCl). This study revealed that the ionic solution should be chosen carefully before performing experiments on these toxins. Similarly, the influence of these ions should be taken into consideration in the design of toxin-based pharmaceuticals. PMID:26475740

  12. 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.

  13. Botulinum Toxin Injections: A Treatment for Muscle Spasms

    Science.gov (United States)

    ... A Treatment for Muscle Spasms What is botulinum toxin? Botulinum toxin is a protein that helps stop muscle ... won't have any harmful effects from the toxin. Botulinum toxin has been used safely for a number ...

  14. EROTYPE IDENTIFICATION OF VIBRIO CHOLERAE BACTERIAWHICH ISOLATED FROM ICE AMONGTUBE AND CUBE ICE TYPE IN FOOD AND BEVERAGES SELLER AT DENPASAR CITY, BALI

    OpenAIRE

    IGP Dhinarananta; IGM Wijaya P; P Ananta WS; P Yuniadi A; M Agus Hendrayana

    2014-01-01

    Cholera is a type of watery diarrhea with specific sign stool containing mucus which resembles rice water. Cholera caused by gram negative bacteria Vibrio cholerae (V.Cholerae). The transmissions of bacteria were through a contaminated food or water.Bali is an international tourism destination with tropical weather where ice is widelyused in food and beverage which bring a risk of cholera through a contaminated ice.Iceshave a risk of bacterial contamination whether from the making and the usa...

  15. Twin outbreak of cholera in rural North Karnataka, India

    Directory of Open Access Journals (Sweden)

    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.

  16. Twin outbreak of cholera in rural North Karnataka, India

    Science.gov (United States)

    Dey, Shuchismita; Parande, Mahantesh V.; Parande, Aisha M.; Lakkannavar, S.L.; Rathore, Poonam K.; Mantur, B.G.; Kholkute, Sanjiva D.; Roy, Subarna

    2014-01-01

    Background & objectives: Successive outbreaks of acute watery diarrhoea occurred in Talikoti and Harnal, located in Bijapur District of the southern Indian State 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. PMID:25366211

  17. Sodium Channel Inhibiting Marine Toxins

    Science.gov (United States)

    Llewellyn, Lyndon E.

    Saxitoxin (STX), tetrodotoxin (TTX) and their many chemical relatives are part of our daily lives. From killing people who eat seafood containing these toxins, to being valuable research tools unveiling the invisible structures of their pharmacological receptor, their global impact is beyond measure. The pharmacological receptor for these toxins is the voltage-gated sodium channel which transports Na ions between the exterior to the interior of cells. The two structurally divergent families of STX and TTX analogues bind at the same location on these Na channels to stop the flow of ions. This can affect nerves, muscles and biological senses of most animals. It is through these and other toxins that we have developed much of our fundamental understanding of the Na channel and its part in generating action potentials in excitable cells.

  18. Entry of Shiga toxin into cells

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; van Deurs, Bo

    Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport......Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport...

  19. Clostridium difficile and C. difficile Toxin Testing

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Clostridium difficile and C. difficile Toxin Testing Share this page: ... C. diff; C diff antigen; GDH Formal name: Clostridium difficile Culture; C. difficile Toxin, A and B; C. ...

  20. Proteomics analysis of toxins-producing dinoflagellates and toxins-contaminated marine organisms

    OpenAIRE

    蒋析文; Jiang, Xiwen

    2012-01-01

    Paralytic shellfish poisoning (PSP) and ciguatera fish poisoning (CFP) are the two major contributors to illnesses caused by dinoflagellate toxins. Paralytic shellfish poisoning toxins (PSTs) are produced by dinoflagellates in the genera Alexandrium, Gymnodinium, and Pyrodinium while ciguatera fish poisoning toxins, such as ciguatoxins (CTXs), are originated from benthic toxic dinoflagellates (Gambierdiscus, Prorocentrum, Ostreopsis, and Coolia species). These toxins are responsible for human...

  1. Bacterial toxin-antitoxin systems

    OpenAIRE

    Guglielmini, Julien; Van Melderen, Laurence

    2011-01-01

    Toxin-antitoxin (TA) systems are composed of two elements: a toxic protein and an antitoxin which is either an RNA (type I and III) or a protein (type II). Type II systems are abundant in bacterial genomes in which they move via horizontal gene transfer. They are generally composed of two genes organized in an operon, encoding a toxin and a labile antitoxin. When carried by mobile genetic elements, these small modules contribute to their stability by a phenomenon denoted as addiction. Recentl...

  2. 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

  3. Evaluation of a rapid polymerase chain reaction based identification technique for Vibrio cholerae isolates.

    Science.gov (United States)

    le Roux, W J; Masoabi, D; de Wet, C M E; Venter, S N

    2004-01-01

    Rapid and accurate identification of waterborne pathogens, such as Vibrio cholerae, in drinking-water sources is important to enable effective resource management and public health protection. Phenotypic systems currently being used for the identification of Vibrio cholerae isolates are time-consuming and the need exists for the development of suitable molecular techniques that can offer both fast and reliable identification. During this study, isolates identified as Vibrio cholerae by means of two different biochemical test systems (API 20E and VITEK 32) were analysed with the polymerase chain reaction (PCR) to compare the reliability of the various identification systems. The selected PCR technique amplified a sequence within the outer membrane protein of Vibrio cholerae, a gene specific for V. cholerae. It was found that out of 243 isolates biochemically identified as V. cholerae with either the API or VITEK system, 21 isolates did not give a positive result with the PCR detection method. Sequencing the 16S rDNA of more than half of these isolates and comparison of the sequences with Internet databases indicated that most of the isolates belonged to the genus Aeromonas. The results indicated that the rapid PCR procedure was more accurate than the API or VITEK systems currently being used for the phenotypic identification of Vibrio cholerae isolates. PMID:15318514

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

    Science.gov (United States)

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

    2015-01-01

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

  5. Effectiveness of Oral Cholera Vaccine in Haiti: 37-Month Follow-Up.

    Science.gov (United States)

    Sévère, Karine; Rouzier, Vanessa; Anglade, Stravinsky Benedict; Bertil, Claudin; Joseph, Patrice; Deroncelay, Alexandra; Mabou, Marie Marcelle; Wright, Peter F; Guillaume, Florence Duperval; Pape, Jean William

    2016-05-01

    The first oral cholera vaccine (OCV) campaign, since its prequalification by the World Health Organization, in response to an ongoing cholera epidemic (reactive vaccination) was successfully conducted in a poor urban slum of approximately 70,000 inhabitants in Port-au-Prince, Haiti, in 2012. Vaccine coverage was 75% of the target population. This report documents the impact of OCV in reducing the number of culture-confirmed cases of cholera admitted to the Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes (GHESKIO) cholera treatment center from that community in the 37 months postvaccination (April 2012-April 30, 2015). Of 1,788 patients with culture-confirmed cholera, 1,770 (99%) were either from outside the vaccine area (1,400 cases) or from the vaccinated community who had not received OCV (370 cases). Of the 388 people from the catchment area who developed culture-confirmed cholera, 370 occurred among the 17,643 people who had not been vaccinated (2.1%) and the remaining 18 occurred among the 52,357 people (0.034%) who had been vaccinated (P < 0.001), for an efficacy that approximates 97.5%. Despite not being designed as a randomized control trial, the very high efficacy is a strong evidence for the effectiveness of OCV as part of an integrated package for the control of cholera in outbreak settings. PMID:26928838

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Toxin yet not toxic: Botulinum toxin in dentistry.

    Science.gov (United States)

    Archana, M S

    2016-04-01

    Paracelsus contrasted poisons from nonpoisons, stating that "All things are poisons, and there is nothing that is harmless; the dose alone decides that something is a poison". Living organisms, such as plants, animals, and microorganisms, constitute a huge source of pharmaceutically useful medicines and toxins. Depending on their source, toxins can be categorized as phytotoxins, mycotoxins, or zootoxins, which include venoms and bacterial toxins. Any toxin can be harmful or beneficial. Within the last 100 years, the perception of botulinum neurotoxin (BTX) has evolved from that of a poison to a versatile clinical agent with various uses. BTX plays a key role in the management of many orofacial and dental disorders. Its indications are rapidly expanding, with ongoing trials for further applications. However, despite its clinical use, what BTX specifically does in each condition is still not clear. The main aim of this review is to describe some of the unclear aspects of this potentially useful agent, with a focus on the current research in dentistry. PMID:27486290

  8. 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.

  9. Quorum sensing-regulated chitin metabolism provides grazing resistance to Vibrio cholerae biofilms.

    Science.gov (United States)

    Sun, Shuyang; Tay, Qi Xiang Martin; Kjelleberg, Staffan; Rice, Scott A; McDougald, Diane

    2015-08-01

    Association of Vibrio cholerae with chitinous surfaces of zooplankton is important for its persistence in marine environments, as it provides accessibility to nutrients and resistance to stresses. Predation by heterotrophic protists has a major impact on the survival of V. cholerae. V. cholerae forms biofilms as its main defensive strategy, and quorum sensing (QS) additionally regulates the production of antiprotozoal factors. The role of chitin and QS regulation in V. cholerae grazing resistance was investigated by exposing V. cholerae wild-type (WT) and QS mutant biofilms grown on chitin flakes to the bacteriotrophic, surface-feeding flagellate Rhynchomonas nasuta. V. cholerae formed more biofilm biomass on chitin flakes compared with nonchitinous surfaces. The growth of R. nasuta was inhibited by WT biofilms grown on chitin flakes, whereas the inhibition was attenuated in QS mutant biofilms. The chitin-dependent toxicity was also observed when the V. cholerae biofilms were developed under continuous flow or grown on a natural chitin source, the exoskeleton of Artemia. In addition, the antiprotozoal activity and ammonium concentration of V. cholerae biofilm supernatants were quantified. The ammonium levels (3.5 mM) detected in the supernatants of V. cholerae WT biofilms grown on chitin flakes were estimated to reduce the number of R. nasuta by >80% in add-back experiments, and the supernatant of QS mutant biofilms was less toxic owing to a decrease in ammonium production. Transcriptomic analysis revealed that the majority of genes involved in chitin metabolism and chemotaxis were significantly downregulated in QS mutant biofilms when grown on chitin compared with the WT biofilms. PMID:25615438

  10. A metalloprotease secreted by the type II secretion system links Vibrio cholerae with collagen.

    Science.gov (United States)

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

    2015-03-01

    Vibrio cholerae is autochthonous to various aquatic niches and is the etiological agent of the life-threatening diarrheal disease cholera. The persistence of V. cholerae in natural habitats is a crucial factor in the epidemiology of cholera. In contrast to the well-studied V. cholerae-chitin connection, scarce information is available about the factors employed by the bacteria for the interaction with collagens. Collagens might serve as biologically relevant substrates, because they are the most abundant protein constituents of metazoan tissues and V. cholerae has been identified in association with invertebrate and vertebrate marine animals, as well as in a benthic zone of the ocean where organic matter, including collagens, accumulates. Here, we describe the characterization of the V. cholerae putative collagenase, VchC, encoded by open reading frame VC1650 and belonging to the subfamily M9A peptidases. Our studies demonstrate that VchC is an extracellular collagenase degrading native type I collagen of fish and mammalian origin. Alteration of the predicted catalytic residues coordinating zinc ions completely abolished the protein enzymatic activity but did not affect the translocation of the protease by the type II secretion pathway into the extracellular milieu. We also show that the protease undergoes a maturation process with the aid of a secreted factor(s). Finally, we propose that V. cholerae is a collagenovorous bacterium, as it is able to utilize collagen as a sole nutrient source. This study initiates new lines of investigations aiming to uncover the structural and functional components of the V. cholerae collagen utilization program. PMID:25561716

  11. Both, toxin A and toxin B, are important in Clostridium difficile infection

    OpenAIRE

    Kuehne, Sarah A; Cartman, Stephen T; Minton, Nigel P.

    2011-01-01

    The bacterium Clostridium difficile is the leading cause of healthcare associated diarrhoea in the developed world and thus presents a major financial burden. The main virulence factors of C. difficile are two large toxins, A and B. Over the years there has been some debate over the respective roles and importance of these two toxins. To address this, we recently constructed stable toxin mutants of C. difficile and found that they were virulent if either toxin A or toxin B was functional. Thi...

  12. 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.

  13. 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

  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. 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.

  16. Antibiotic Resistance and Integron of Vibrio cholerae Detection from School Street Foods in Jakarta

    OpenAIRE

    NADIA DEASHINTA; DIANA ELIZABETH WATURANGI; YOGIARA

    2007-01-01

    Street foods represent foods and beverages prepared by vendors in streets or other public places, i.e. schools. Food safety issues perceive street foods as a potential major public risk. Street foods contaminated with toxigenic Vibrio cholerae may lead to serious poisoning to school-age children. In this study, 17 isolates of V. cholerae were obtained from nine (45%) of total 20 street foods samples collected in Jakarta. Five (29%) were confirmed to be V. cholerae O1, serotype Ogawa using bio...

  17. 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...

  18. [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

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

    DEFF Research Database (Denmark)

    Matz, Carsten; McDougald, D.; Moreno, A.M.; Yung, P.Y.; Yildiz, F.H.; Kjelleberg, S.

    2005-01-01

    . Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. our data show that biofilms are the protective agent enabling V. cholerae to...... of V. cholerae biofilms was found to be widespread among toxigenic and nontoxigenic isolates. Our results provide a mechanistic explanation for the adaptive advantage of surf ace-associated growth in the environmental persistence of V. cholerae and suggest an important contribution of protozoan...

  20. Human immune response to Vibrio cholerae O1 whole cells and isolated outer membrane antigens.

    OpenAIRE

    Richardson, K; Kaper, J B; Levine, M M

    1989-01-01

    The serum immunoglobulin G (IgG) and mucosal secretory IgA (SIgA) response of human volunteers challenged with Vibrio cholerae O1 was analyzed for reactivity to V. cholerae O1 antigens by the immunoblot technique. Components of both in vitro- and in vivo (rabbit ligated ileal loop)-grown V. cholerae O1 were separated by sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis. Postchallenge serum IgG reacted uniquely with 15 antigens and with greater intensity than did prechallenge seru...

  1. Shigella Sonnei and Shiga Toxin

    Centers for Disease Control (CDC) Podcasts

    2016-07-28

    Katherine Lamba, an infectious disease epidemiologist with the California Department of Public Health, discusses Shiga Toxin producing Shigella sonnei.  Created: 7/28/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/28/2016.

  2. Risk Assessment of Shellfish Toxins

    Directory of Open Access Journals (Sweden)

    Rex Munday

    2013-11-01

    Full Text Available Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved.

  3. Food irradiation and bacterial toxins

    International Nuclear Information System (INIS)

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods. (author)

  4. 苏州市部分水产品分离的霍乱弧菌耐药状况及毒力基因分析%Analysis of antibiotc resistance and virulence genes of vibrio cholerae isolated from part of aquatic products in Suzhou

    Institute of Scientific and Technical Information of China (English)

    张梦寒; 王丽; 李建

    2013-01-01

    目的:分析苏州市部分养殖水产品霍乱弧菌分布情况,并对其进行耐药性分析和毒力基因检测.方法:对甲鱼、牛蛙及其养殖用水等样品,进行霍乱弧菌的分离、鉴定及耐药性分析和4种毒力基因的PCR检测.结果:分离到的18株霍乱弧菌标本中O139群8株,O1群4株,其余6株为非O1非O139群霍乱弧菌.经耐药性分析,对试验的12种抗生素均无100%敏感株;对多粘菌素B和红霉素的中介率高达83.3%.检测的4个毒力基因中,阳性率最高的是Zot基因.结论:分离到的18株霍乱弧菌血清型有一定的种属相关特性,中介耐药性突出,毒力基因阳性率较高.%Objective: To analyze the distribution of vibrio cholerae in some breeding aquatic products in Suzhou, to understand the antibiotic resistance and virulence genes. Methods; Vibrio cholerae was isolated from samples of soft - shelled turtles, bullfrogs and breeding water for identification. The detected vibrio cholerae strains were analyzed for antibiotic resistance. PCR method was adopted to detect 4 kinds of virulence genes. Results; Eighteen strains of vibrio cholerae were isolated, including serogroup 0139(8 strains) , serogroup 01 (4 strains) , non - 01 and non - 0139(6 strains). The antibiotic resistance result indicated that none of the 18 vibrio cholerae strains were 100% sensitive to 12 kinds of tested antibiotics; while the antibiotic intermediate resistance rate to polymyxin B and erythromycin was up to 83. 3%. Of four virulence genes, zonula occludens toxin gene was the most prevalent. Conclusion; There was certain species -dependent characteristics in 18 strains of vibrio cholerae by serological typing, prominent antibiotic intermediary resistance and high positive rate of virulence gene were also the features of the 18 vibrio cholerae strains.

  5. Antibiotic Resistance and Integron of Vibrio cholerae Detection from School Street Foods in Jakarta

    Directory of Open Access Journals (Sweden)

    NADIA DEASHINTA

    2007-06-01

    Full Text Available Street foods represent foods and beverages prepared by vendors in streets or other public places, i.e. schools. Food safety issues perceive street foods as a potential major public risk. Street foods contaminated with toxigenic Vibrio cholerae may lead to serious poisoning to school-age children. In this study, 17 isolates of V. cholerae were obtained from nine (45% of total 20 street foods samples collected in Jakarta. Five (29% were confirmed to be V. cholerae O1, serotype Ogawa using biochemical tests and serological identification. Of the 17 V. cholerae isolates 47% proved to be resistant to ampicillin, 35% to trimethoprim, 17.6% to tetracycline, and 17.6% to streptomycin. A class 1 integrons bearing streptomycin/spectinomycin resistant gene cassette of aadA1c were discovered on isolate Vc25n. This may leads to horizontal transfer of the antibiotic resistant genes to other bacteria.

  6. 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.

  7. 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).

  8. 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

  9. 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)

  10. 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.

  11. 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

  12. 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...

  13. 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

  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. Impact of Religious and Cultural practices on recent Cholera outbreak in a village of South India

    OpenAIRE

    Naveen K H; Sumanth Mallikarjuna Majgi; Khan, Mudassir A.

    2012-01-01

    Every year, there are an estimated 3–5 million cholera cases and 100000–120000 deaths due to cholera. Religion and culture continue to influence the sharing of water by certain communities of Indian villages, especially the scheduled casteMethodFollowing the information of many admissions in Krishnarajendra (K.R.) hospital and cheluvamba hospital, the department of Community Medicine, Mysore investigated the outbreak. Majority of cases were from Harohalli village. The data was collected by us...

  16. The Impact of Water, Sanitation and Hygiene Interventions to Control Cholera: A Systematic Review.

    OpenAIRE

    Taylor, DL; Kahawita, TM; Cairncross, S; Ensink, JH

    2015-01-01

    Background and Methods Cholera remains a significant threat to global public health with an estimated 100,000 deaths per year. Water, sanitation and hygiene (WASH) interventions are frequently employed to control outbreaks though evidence regarding their effectiveness is often missing. This paper presents a systematic literature review investigating the function, use and impact of WASH interventions implemented to control cholera. Results The review yielded eighteen studies and of the five st...

  17. Genetic Variation of Vibrio cholerae during Outbreaks, Bangladesh, 2010–2011

    OpenAIRE

    Rashed, Shah M.; Azman, Andrew S.; Alam, Munirul; Li, Shan; Sack, David A.; Morris, J Glenn; Longini, Ira; Siddique, Abul Kasem; Iqbal, Anwarul; Huq, Anwar; Colwell, Rita R.; Sack, R Bradley; Stine, O. Colin

    2014-01-01

    Cholera remains a major public health problem. To compare the relative contribution of strains from the environment with strains isolated from patients during outbreaks, we performed multilocus variable tandem repeat analyses on samples collected during the 2010 and 2011 outbreak seasons in 2 geographically distinct areas of Bangladesh. A total of 222 environmental and clinical isolates of V. cholerae O1 were systematically collected from Chhatak and Mathbaria. In Chhatak, 75 of 79 isolates w...

  18. 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...

  19. Identification of a Vibrio cholerae chemoreceptor that senses taurine and amino acids as attractants

    OpenAIRE

    So-ichiro Nishiyama; Yohei Takahashi; Kentaro Yamamoto; Daisuke Suzuki; Yasuaki Itoh; Kazumasa Sumita; Yumiko Uchida; Michio Homma; Katsumi Imada; Ikuro Kawagishi

    2016-01-01

    Vibrio cholerae, the etiological agent of cholera, was found to be attracted by taurine (2-aminoethanesulfonic acid), a major constituent of human bile. Mlp37, the closest homolog of the previously identified amino acid chemoreceptor Mlp24, was found to mediate taxis to taurine as well as L-serine, L-alanine, L-arginine, and other amino acids. Methylation of Mlp37 was enhanced upon the addition of taurine and amino acids. Isothermal titration calorimetry demonstrated that a purified periplasm...

  20. Use of oral cholera vaccines in an outbreak in Vietnam: a case control study.

    Directory of Open Access Journals (Sweden)

    Dang Duc Anh

    Full Text Available BACKGROUND: Killed oral cholera vaccines (OCVs are available but not used routinely for cholera control except in Vietnam, which produces its own vaccine. In 2007-2008, unprecedented cholera outbreaks occurred in the capital, Hanoi, prompting immunization in two districts. In an outbreak investigation, we assessed the effectiveness of killed OCV use after a cholera outbreak began. METHODOLOGY/PRINCIPAL FINDINGS: From 16 to 28 January 2008, vaccination campaigns with the Vietnamese killed OCV were held in two districts of Hanoi. No cholera cases were detected from 5 February to 4 March 2008, after which cases were again identified. Beginning 8 April 2008, residents of four districts of Hanoi admitted to one of five hospitals for acute diarrhea with onset after 5 March 2008 were recruited for a matched, hospital-based, case-control outbreak investigation. Cases were matched by hospital, admission date, district, gender, and age to controls admitted for non-diarrheal conditions. Subjects from the two vaccinated districts were evaluated to determine vaccine effectiveness. 54 case-control pairs from the vaccinated districts were included in the analysis. There were 8 (15% and 16 (30% vaccine recipients among cases and controls, respectively. The vaccine was 76% protective against cholera in this setting (95% CI 5% to 94%, P = 0.042 after adjusting for intake of dog meat or raw vegetables and not drinking boiled or bottled water most of the time. CONCLUSIONS/SIGNIFICANCE: This is the first study to explore the effectiveness of the reactive use of killed OCVs during a cholera outbreak. Our findings suggest that killed OCVs may have a role in controlling cholera outbreaks.

  1. Avian cholera causes marine bird mortality in the Bering Sea of Alaska

    Science.gov (United States)

    Bodenstein, Barbara; Kimberlee Beckmen; Gay Sheffield; Kathy Kuletz; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

    2015-01-01

    The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

  2. The complete genome sequence of Vibrio cholerae: a tale of two chromosomes and of two lifestyles

    OpenAIRE

    Schoolnik, Gary K.; Yildiz, Fitnat H.

    2000-01-01

    Vibrio cholerae O1 has figured prominently in the history of infectious diseases as a cause of periodic global epidemics, an affliction of refugees in areas of social strife and as the disease first subjected to modern epidemiological analysis during the classic investigations of John Snow in mid-19th century London [1]. Thus, publication of the entire genome sequence of V. cholerae O1 (biotype El Tor) in Nature [2] by a consortium of investigators from The Institute for Genomic Research, the...

  3. Social and News Media Enable Estimation of Epidemiological Patterns Early in the 2010 Haitian Cholera Outbreak

    OpenAIRE

    Chunara, Rumi; Andrews, Jason R.; Brownstein, John S.

    2012-01-01

    During infectious disease outbreaks, data collected through health institutions and official reporting structures may not be available for weeks, hindering early epidemiologic assessment. By contrast, data from informal media are typically available in near real-time and could provide earlier estimates of epidemic dynamics. We assessed correlation of volume of cholera-related HealthMap news media reports, Twitter postings, and government cholera cases reported in the first 100 days of the 201...

  4. 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.

  5. The Role of Temperature in the Environmental Survival and Transmission of Vibrio cholerae

    OpenAIRE

    Townsley, Yolanda Frances Anne

    2015-01-01

    V. cholerae the causative agent of the diarrheal disease cholera is able to thrive within the small intestines of human hosts, however, between epidemics is found as an autochthonous member of aquatic microbial communities throughout the world (Kaper, 1979; Gil, 2004; Huq, 2005). This pathogen must endure changes in environmental parameters such as temperature, salinity, pH, and iron availability between their human hosts and aquatic reservoirs as well as within the environment. Temperature...

  6. 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

  7. 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...

  8. 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...

  9. 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.

  10. 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.

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

    OpenAIRE

    Michael Emch; Mohammad Yunus; Mohammad Ali; Sophia Giebultowicz

    2011-01-01

    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 house...

  12. Solar disinfection of drinking water protects against cholera in children under 6 years of age

    OpenAIRE

    Conroy, R; Meegan, M; Joyce, T; McGuigan, K; Barnes, J

    2001-01-01

    BACKGROUND AND AIMS—We have previously reported a reduction in risk of diarrhoeal disease in children who used solar disinfected drinking water. A cholera epidemic, occurring in an area of Kenya in which a controlled trial of solar disinfection and diarrhoeal disease in children aged under 6 had recently finished, offered an opportunity to examine the protection offered by solar disinfection against cholera.
METHODS—In the original trial, all children aged under 6 in a Ma...

  13. Anthrax toxin receptor 2-dependent lethal toxin killing in vivo.

    Directory of Open Access Journals (Sweden)

    Heather M Scobie

    2006-10-01

    Full Text Available Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2 have a related integrin-like inserted (I domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in the absence of metal ions, we reasoned that D683 mutant forms of PA might specifically interact with ANTXR2. We show here that this is the case. The differential ability of ANTXR1 and ANTXR2 to bind D683 mutant PA proteins was mapped to nonconserved receptor residues at the binding interface with PA domain 2. Moreover, a D683K mutant form of PA that bound specifically to human and rat ANTXR2 mediated killing of rats by anthrax lethal toxin, providing strong evidence for the physiological importance of ANTXR2 in anthrax disease pathogenesis.

  14. Immunological cross-reactivity in the absence of DNA homology between Pseudomonas toxin A and diphtheria toxin.

    OpenAIRE

    Sadoff, J C; Buck, G A; Iglewski, B H; Bjorn, M J; Groman, N B

    1982-01-01

    The immunodominant determinant of Pseudomonas toxin A was shown to cross-react with a normally inaccessible determinant in fragment A of diphtheria toxin. Trypsin-treated diphtheria toxin and fragment A of diphtheria toxin inhibited binding of toxin A antibody to whole toxin A, whereas whole diphtheria toxin did not inhibit this reaction. However, even at the lowest stringency no hybridization was detected between diphtheria tox probe and Pseudomonas aeruginosa DNA.

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

    Science.gov (United States)

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

    2016-09-01

    Cell to cell communication facilitated by chemical signals plays crucial roles in regulating various cellular functions in bacteria. Indole, one such signaling molecule has been demonstrated to control various bacterial phenotypes such as biofilm formation and virulence in diverse bacteria including Vibrio cholerae. The present study explores some key factors involved in indole production and the subsequent pathogenesis of V. cholerae. Indole production was higher at 37 °C than at 30 °C, although the growth at 37 °C was slightly higher. A positive correlation was observed between indole production and biofilm formation in V. cholerae. Maximum indole production was detected at pH 7. There was no significant difference in indole production between clinical and environmental V. cholerae isolates, although indole production in one environmental isolate was significantly different. Both growth and indole production showed relevant changes with differences in salinity. An indole negative mutant strain was constructed using transposon mutagenesis and the direct effect of indole on the virulence of V. cholerae was evaluated using Galleria mellonella larvae model. Comparison to the wild type strain, the mutant significantly reduced the mortality of G. mellonella larvae which regained its virulence after complementation with exogenous indole. A gene involved in indole production and the virulence of V. cholerae was identified. PMID:27407302

  16. 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.

  17. 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.

  18. [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. PMID:27029123

  19. 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.

  20. 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)

  1. Nanodiscs for immobilization of lipid bilayers and membrane receptors: kinetic analysis of cholera toxin binding to a glycolipid receptor

    DEFF Research Database (Denmark)

    Borch, Jonas; Torta, Federico; Sligar, Stephen G; Roepstorff, Peter

    2008-01-01

    Nanodiscs are self-assembled soluble discoidal phospholipids bilayers encirculated by an amphipathic protein that together provide a functional stabilized membrane disk for the incorporation of membrane-bound and membrane-associated molecules. The scope of the present work is to investigate how n...

  2. CRYSTAL-STRUCTURE OF A CHOLERA TOXIN-RELATED HEAT-LABILE ENTEROTOXIN FROM ESCHERICHIA-COLI

    NARCIS (Netherlands)

    SIXMA, TK; PRONK, SE; KALK, KH; WARTNA, ES; VANZANTEN, BAM; WITHOLT, B; HOL, WGJ

    1991-01-01

    Examination of the structure of Escherichia coli heat-labile enterotoxin in the AB5 complex at a resolution of 2.3 angstrom reveals that the doughnut-shaped B pentamer binds the enzymatic A subunit using a hairpin of the A2 fragment, through a highly charged central pore. Putative ganglioside G(M1-)

  3. Why do we study animal toxins?

    Science.gov (United States)

    Zhang, Yun

    2015-07-18

    Venom (toxins) is an important trait evolved along the evolutionary tree of animals. Our knowledges on venoms, such as their origins and loss, the biological relevance and the coevolutionary patterns with other organisms are greatly helpful in understanding many fundamental biological questions, i.e., the environmental adaptation and survival competition, the evolution shaped development and balance of venoms, and the sophisticated correlations among venom, immunity, body power, intelligence, their genetic basis, inherent association, as well as the cost-benefit and trade-offs of biological economy. Lethal animal envenomation can be found worldwide. However, from foe to friend, toxin studies have led lots of important discoveries and exciting avenues in deciphering and fighting human diseases, including the works awarded the Nobel Prize and lots of key clinic therapeutics. According to our survey, so far, only less than 0.1% of the toxins of the venomous animals in China have been explored. We emphasize on the similarities shared by venom and immune systems, as well as the studies of toxin knowledge-based physiological toxin-like proteins/peptides (TLPs). We propose the natural pairing hypothesis. Evolution links toxins with humans. Our mission is to find out the right natural pairings and interactions of our body elements with toxins, and with endogenous toxin-like molecules. Although, in nature, toxins may endanger human lives, but from a philosophical point of view, knowing them well is an effective way to better understand ourselves. So, this is why we study toxins. PMID:26228472

  4. Optimal intervention strategies for cholera outbreak by education and chlorination

    Science.gov (United States)

    Bakhtiar, Toni

    2016-01-01

    This paper discusses the control of infectious diseases in the framework of optimal control approach. A case study on cholera control was studied by considering two control strategies, namely education and chlorination. We distinct the former control into one regarding person-to-person behaviour and another one concerning person-to-environment conduct. Model are divided into two interacted populations: human population which follows an SIR model and pathogen population. Pontryagin maximum principle was applied in deriving a set of differential equations which consists of dynamical and adjoin systems as optimality conditions. Then, the fourth order Runge-Kutta method was exploited to numerically solve the equation system. An illustrative example was provided to assess the effectiveness of the control strategies toward a set of control scenarios.

  5. 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

  6. Massive Fluid Requirements and an Unusual BUN/Creatinine Ratio for Pre-Renal Failure in Patients with Cholera

    OpenAIRE

    Tariq, Muhammad; Memon, Murtaza; Jafferani, Asif; Shoukat, Sana; Gowani, Saqib Ali; Nusrat, Rabeeya; Riaz, Mehmood; Patel, Junaid; Jamil, Bushra; Raymond A. Smego

    2009-01-01

    Background Cholera is an important infectious cause of secretory diarrhea. The primary symptom of infection is the sudden onset of watery diarrhea with subsequent volume depletion causing renal insufficiency. The objective of this research is to study the level of dehydration at presentation and subsequent fluid management in patients with cholera. Methods This study was conducted on 191 patients of Cholera admitted at a tertiary care hospital in Karachi, Pakistan during the period of 5 years...

  7. 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....

  8. A Survey of Etiologic , Clinical Manifestations and Laboratory Findings of Patients with Cholera in Province Hamadan Epidemy in 1998

    OpenAIRE

    F. Keramt; M. Ranjbar; H. Mahjub

    2003-01-01

    Cholera is a disease with acute diarrhea caused by vibrio cholera which it’s serogroups O1 is more responsible for several epidemy in numerous countries . There are two biotypes classic and eltor that has three serotypes ogawa , inaba and hikojima . This survey with beginning cholera epidemy in Hamadan was performed with aim to investigation etiology , clinical manifestation and laboratory findings in referred patients to health services in Hamadan province. The method...

  9. Sociocultural Determinants of Anticipated Oral Cholera Vaccine Acceptance in Three African Settings: a Meta-analytic Approach.

    OpenAIRE

    Sundaram, Neisha; Schaetti, Christian; Merten, Sonja; Schindler, Christian; Ali, Said M.; Nyambedha, Erick O; Lapika, Bruno; Chaignat, Claire-Lise; Hutubessy, Raymond; Weiss, Mitchell G

    2016-01-01

    Background Controlling cholera remains a significant challenge in Sub-Saharan Africa. In areas where access to safe water and sanitation are limited, oral cholera vaccine (OCV) can save lives. Establishment of a global stockpile for OCV reflects increasing priority for use of cholera vaccines in endemic settings. Community acceptance of vaccines, however, is critical and sociocultural features of acceptance require attention for effective implementation. This study identifies and compares soc...

  10. Exfoliative Toxins of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michal Bukowski

    2010-05-01

    Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  11. [Factors contributing to endemic cholera in Douala, Cameroon].

    Science.gov (United States)

    Guévart, E; Noeske, J; Solle, J; Essomba, J M; Edjenguele, Mbonji; Bita, A; Mouangue, A; Manga, B

    2006-06-01

    Cholera has been endemic in Douala, Cameroon since 1971. A number of environmental factors favourize the survival of the Vibrio in Douala including location at the mouth of Wouri delta on the Atlantic Ocean, sandy clay soil, shallow dirty polluted foul-smelling groundwater, presence of vast expanses of swamp, streams/drainage ditches infested with algae, and high temperatures with low rainfall and drought during certain periods of the year. Most outbreaks have started in Bepanda, a slum area built on a garbage dump in a swampy zone fed by drainage ditches carrying the faecal pollution from neighbouring upstream districts. It is a densely overcrowded area of uncontrolled urbanization generated by the influx of poor city new-comers who live without adequate access to clean water or basic sanitary facilities. The most affected areas are those resulting from recent unregulated urban sprawl in polluted swamp zones or garbage dumps. Since access to the public water system is inadequate with only 65000 persons connected for 3 million inhabitants, dwellers in most areas must take water from the 70000 urban wells (estimated in 2004) that are often not more than 1.5 m deep. Sewage facilities are insufficient to provide complete evacuation of solid and liquid waste. The network of rivers, streams and man-made ditches waste are poorly maintained and often overflow during the rainy season. The contents of latrines are often discharged directly into the environment. Social factors such as the reformation of urban tribes and persistence of traditional attitudes toward waste disposal and water use have not only led to high-risk behaviour but also created barriers to sanitation and hygiene education. With an inadequate sanitation inspection system, a large but purely accessible public health system and a highly disorganized private health sector exists, effective preventive measures are difficult to implement. The combination of these factors probably account for the endemicity of

  12. Botulinum toxin: Bioweapon & magic drug

    OpenAIRE

    Dhaked, Ram Kumar; Singh, Manglesh Kumar; Singh, Padma; Gupta, Pallavi

    2010-01-01

    Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal p...

  13. Botulinum Toxin in Pediatric Neurology

    OpenAIRE

    Moawad, Eman M. I.; Abdallah, Enas Abdallah Ali

    2015-01-01

    Botulinum neurotoxins are natural molecules produced by anaerobic spore-forming bacteria called Clostradium boltulinum. The toxin has a peculiar mechanism of action by preventing the release of acetylcholine from the presynaptic membrane. Consequently, it has been used in the treatment of various neurological conditions related to muscle hyperactivity and/or spasticity. Also, it has an impact on the autonomic nervous system by acting on smooth muscle, leading to its use in the management of p...

  14. Cost-benefit comparisons of investments in improved water supply and cholera vaccination programs.

    Science.gov (United States)

    Jeuland, Marc; Whittington, Dale

    2009-05-18

    This paper presents the first cost-benefit comparison of improved water supply investments and cholera vaccination programs. Specifically, we compare two water supply interventions -- deep wells with public hand pumps and biosand filters (an in-house, point-of-use water treatment technology) -- with two types of cholera immunization programs with new-generation vaccines -- general community-based and targeted and school-based programs. In addition to these four stand-alone investments, we also analyze five combinations of water and vaccine interventions: (1) borehole+hand pump and community-based cholera vaccination, (2) borehole+hand pump and school-based cholera vaccination, (3) biosand filter and community-based cholera vaccination, (4) biosand filter and school-based cholera vaccination, and (5) biosand filter and borehole+hand pump. Using recent data applicable to developing country locations for parameters such as disease incidence, the effectiveness of vaccine and water supply interventions against diarrheal diseases, and the value of a statistical life, we construct cost-benefit models for evaluating these interventions. We then employ probabilistic sensitivity analysis to estimate a frequency distribution of benefit-cost ratios for all four interventions, given a wide variety of possible parameter combinations. Our results demonstrate that there are many plausible conditions in developing countries under which these interventions will be attractive, but that the two improved water supply interventions and the targeted cholera vaccination program are much more likely to yield attractive cost-benefit outcomes than a community-based vaccination program. We show that implementing community-based cholera vaccination programs after borehole+hand pump or biosand filters have already been installed will rarely be justified. This is especially true when the biosand filters are already in place, because these achieve substantial cholera risk reductions on their own

  15. Cholera in Vietnam: Changes in Genotypes and Emergence of Class I Integrons Containing Aminoglycoside Resistance Gene Cassettes in Vibrio cholerae O1 Strains Isolated from 1979 to 1996

    OpenAIRE

    Dalsgaard, A; Forslund, A; Tam, N. V.; Vinh, D. X.; Cam, P. D.

    1999-01-01

    The number of cholera cases and the mortality rates reported from different regions of Vietnam varied considerably in the period from 1979 to 1996, with between 2,500 and 6,000 cases reported annually from 1992 to 1995. Annual mortality rates ranged from 2.0 to 9.6% from 1979 to 1983 to less than 1.8% after 1983. Major cholera outbreaks were reported from the High Plateau region for the first time in 1994 and 1995; this is an area with limited access to health services and safe drinking-water...

  16. 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.

  17. Oral cholera vaccine use in Zanzibar: socioeconomic and behavioural features affecting demand and acceptance

    Directory of Open Access Journals (Sweden)

    Chaignat Claire-Lise

    2009-04-01

    Full Text Available Abstract Background Cholera remains a serious public health problem in low-income countries despite efforts in the past to promote oral rehydration therapy as major treatment. In 2007, the majority of worldwide cases (94% and deaths (99% were reported from Africa. To improve cholera control efforts in addition to maintaining and improving existing water supply, sanitation and hygiene behaviour measures, the World Health Organization has recently started to consider the use of vaccines as an additional public health tool. To assess this new approach in endemic settings, a project was launched in Zanzibar to vaccinate 50,000 individuals living in communities at high risk of cholera with an oral two-dose vaccine (Dukoral®. Immunisation programmes in low-income countries have suffered a reduced coverage or were even brought to a halt because of an ignorance of local realities. To ensure the success of vaccination campaigns, implementers have to consider community-held perceptions and behaviours regarding the infectious disease and the vaccine of interest. The main aim of this study is to provide advice to the Ministry of Health and Social Welfare of Zanzibar regarding routine introduction of an oral cholera vaccine from a socioeconomic and behavioural perspective as part of a long-term development for a sustained cholera prevention strategy. Methods and design Qualitative and quantitative methods of health social science research will be applied on four stakeholder levels before and after the mass vaccination campaign. Rapid assessment individual interviews and focus groups will be used to describe cholera- and vaccine-related views of policy makers, health care professionals and community representatives. The cultural epidemiological approach will be employed on the individual household resident level in a repeated cross-sectional design to estimate determinants of anticipated and actual oral cholera vaccine acceptance. Discussion The study

  18. [Use of botulinum toxin in strabismus].

    Science.gov (United States)

    Wabbels, B

    2016-07-01

    Botulinum toxin can be a useful tool for treating acute sixth nerve palsy and excessive eye deviations due to unstable Graves' disease, when surgery is not yet possible. The diagnostic injection for estimation of possible postoperative double vision also makes sense. In convergence spasms, periocular botulinum toxin injections can be a therapeutic option. Botulinum toxin is not a first line option in infantile esotropia without binocularity or in adult horizontal strabismus. Side effects include ptosis and vertical deviations. PMID:27369733

  19. Quantitative microtiter cytotoxicity assay for Shigella toxin.

    OpenAIRE

    Gentry, M. K.; Dalrymple, J M

    1980-01-01

    The cytotoxic activity of Shigella dysenteriae 1 was assayed by exposing HeLa cells in microtiter cultures to dilutions of toxin. Exposure to toxin caused either failure of cells in suspension to attach or detachment of cells from established monolayers. Estimates of toxin potency were made by staining residual cells with crystal violet and visually inspecting the stained plates. Quantitation of the cytotoxic effect was made possible by eluting and spectrophotometrically measuring the stain. ...

  20. Application of Botulinum Toxin in Pain Management

    OpenAIRE

    Sim, Woo Seog

    2011-01-01

    Botulinum toxin has been used for the treatment of many clinical disorders by producing temporary skeletal muscle relaxation. In pain management, botulinum toxin has demonstrated an analgesic effect by reducing muscular hyperactivity, but recent studies suggest this neurotoxin could have direct analgesic mechanisms different from its neuromuscular actions. At the moment, botulinum toxin is widely investigated and used in many painful diseases such as myofascial syndrome, headaches, arthritis,...

  1. Amplified fragment length polymorphism of clinical and environmental Vibrio cholerae from a freshwater environment in a cholera-endemic area, India

    Directory of Open Access Journals (Sweden)

    Sharma Naresh C

    2011-09-01

    Full Text Available Abstract Background The region around Chandigarh in India has witnessed a resurgence of cholera. However, isolation of V. cholerae O1 from the environment is infrequent. Therefore, to study whether environmental nonO1-nonO139 isolates, which are native to the aquatic ecosystem, act as precursors for pathogenic O1 strains, their virulence potential and evolutionary relatedness was checked. Methods V. cholerae was isolated from clinical cases of cholera and from water and plankton samples collected from freshwater bodies and cholera-affected areas. PCR analysis for the ctxA, ctxB, tcpA, toxT and toxR genes and AFLP with six primer combinations was performed on 52 isolates (13 clinical, 34 environmental and 5 reference strains. Results All clinical and 3 environmental isolates belonged to serogroup O1 and remaining 31 environmental V. cholerae were nonO1-nonO139. Serogroup O1 isolates were ctxA, tcpA (ElTor, ctxB (Classical, toxR and toxT positive. NonO1-nonO139 isolates possessed toxR, but lacked ctxA and ctxB; only one isolate was positive for toxT and tcpA. Using AFLP, 2.08% of the V. cholerae genome was interrogated. Dendrogram analysis showed one large heterogeneous clade (n = 41, with two compact and distinct subclades (1a and 1b, and six small mono-phyletic groups. Although V. cholerae O1 isolates formed a distinct compact subclade, they were not clonal. A clinical O1 strain clustered with the nonO1-nonO139 isolates; one strain exhibited 70% similarity to the Classical control strain, and all O1 strains possessed an ElTor variant-specific fragment identified with primer ECMT. Few nonO1-nonO139 isolates from widely separated geographical locations intermingled together. Three environmental O1 isolates exhibited similar profiles to clinical O1 isolates. Conclusion In a unique study from freshwater environs of a cholera-endemic area in India over a narrow time frame, environmental V. cholerae population was found to be highly heterogeneous

  2. Synthesis and Biology of Cyclic Imine Toxins, An Emerging Class of Potent, Globally Distributed Marine Toxins

    OpenAIRE

    Stivala, Craig E.; Benoit, Evelyne; Araoz, Romulo; Servent, Denis; Novikov, Alexei; Molgó, Jordi; Zakarian, Armen

    2015-01-01

    From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulat...

  3. Protein Translocation by Bacterial Toxin Channels: A Comparison of Diphtheria Toxin and Colicin Ia

    OpenAIRE

    Wu, Zhengyan; Jakes, Karen S.; Samelson-Jones, Ben S.; Lai, Bing; Zhao, Gang; London, Erwin; Finkelstein, Alan

    2006-01-01

    Regions of both colicin Ia and diphtheria toxin N-terminal to the channel-forming domains can be translocated across planar phospholipid bilayer membranes. In this article we show that the translocation pathway of diphtheria toxin allows much larger molecules to be translocated than does the translocation pathway of colicin Ia. In particular, the folded A chain of diphtheria toxin is readily translocated by that toxin but is not translocated by colicin Ia. This difference cannot be attributed...

  4. Botulinum Toxin; Bioterror and Biomedicinal Agent

    Directory of Open Access Journals (Sweden)

    Jiri Patocka

    2006-04-01

    Full Text Available Botulinum toxin is a group of seven homologous, highly poisonous proteins isolated fromfermentation of the anaerobic bacterium Clostridium botulinum, which naturally occurs in soiland can grow on many meats and vegetables. Botulinum toxin causes neuromuscular disordercalled botulism, which is a potentially lethal disease. There are three types of botulism: Food,wound, and infant botulism. It can lead to death unless appropriate therapy is done. Due to theseverity and potency of botulinum toxin, its importance as a biological weapon is of majorconcern to public health officials. Nevertheless, botulinum toxin is also medicament.

  5. Shiga Toxin (Stx) Classification, Structure, and Function

    OpenAIRE

    Melton-Celsa, Angela R.

    2014-01-01

    Shiga toxin (Stx) is one of the most potent bacterial toxins known. Stx is found in Shigella dysenteriae 1 and in some serogroups of Escherichia coli (called Stx1 in E. coli). In addition to or instead of Stx1, some E. coli strains produce a second type of Stx, Stx2, that has the same mode of action as Stx/Stx1 but that is antigenically distinct. Because subtypes of each toxin have been identified, the prototype toxin for each group is now designated Stx1a or Stx2a. The Stxs consist of two ma...

  6. [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

  7. 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

  8. Characterization of Toxin Plasmids in Clostridium perfringens Type C Isolates▿

    OpenAIRE

    Gurjar, Abhijit; Li, Jihong; McClane, Bruce A.

    2010-01-01

    Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin and beta toxin but often produce additional toxins, e.g., beta2 toxin or enterotoxin. Since plasmid carriage of toxin-encoding genes has not been systematically investigated for type C isolates, the current study used Southern blot hybridization of pulsed-field gels to test whether several toxin genes are plasm...

  9. 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

  10. 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

  11. Botulinum toxin: The Midas touch.

    Science.gov (United States)

    Shilpa, P S; Kaul, Rachna; Sultana, Nishat; Bhat, Suraksha

    2014-01-01

    Botulinum Toxin (BT) is a natural molecule produced during growth and autolysis of bacterium called Clostridium botulinum. Use of BT for cosmetic purposes has gained popularity over past two decades, and recently, other therapeutic uses of BT has been extensively studied. BT is considered as a minimally invasive agent that can be used in the treatment of various orofacial disorders and improving the quality of life in such patients. The objective of this article is to review the nature, mechanism of action of BT, and its application in various head and neck diseases. PMID:24678189

  12. Serum Anti-Vibrio cholerae Immunoglobulin Isotype in BALB/c Mice Immunized With ompW-Loaded Chitosan

    Directory of Open Access Journals (Sweden)

    Fasihi-Ramandi

    2016-05-01

    Full Text Available Background Chitosan, a liner polysaccharide, is a biocompatible and safe material for the delivery of therapeutic proteins and antigens, particularly via mucosal systems. Objectives In this study, the production of antibodies in response to outer membrane protein W (ompW-loaded chitosan in BALB/c mice was evaluated. Materials and Methods Mice were subjected to intraperitoneal injection of ompW or nasal administration of ompW-loaded chitosan on days 1, 14, and 28, and the antibodies were measured on day 42 with ELISA. Results The titration of antibodies indicated that the nasal administration of ompW-loaded chitosan was better able to stimulate the immune response compared to intraperitoneal injections. However, the titration of total and IgG isotypes showed a significant difference between intraperitoneal and nasal immunization (P < 0.01. A significant difference was also seen in serum IgA isotypes at over 1/80 titrations, but not at lower dilutions (P < 0.01. Despite the serum antibodies, the results of lavage fluid analysis revealed that the IgG and IgA isotypes in the mice subjected to nasal immunization with ompW-loaded chitosan were significantly higher than in the other group (P < 0.01. Conclusions Based on the preliminary results presented in this research, it is suggested that ompW-loaded chitosan could be a suitable choice for nasal application to immunize the host against Vibrio cholerae. However, more work is required to determine the efficiency of the antibodies in neutralizing the bacterial toxin or bacterial movement.

  13. Clostridial Glucosylating Toxins Enter Cells via Clathrin-Mediated Endocytosis

    OpenAIRE

    Papatheodorou, Panagiotis; Zamboglou, Constantinos; Genisyuerek, Selda; Guttenberg, Gregor; Aktories, Klaus

    2010-01-01

    Clostridium difficile toxin A (TcdA) and toxin B (TcdB), C. sordellii lethal toxin (TcsL) and C. novyi α-toxin (TcnA) are important pathogenicity factors, which represent the family of the clostridial glucosylating toxins (CGTs). Toxin A and B are associated with antibiotic-associated diarrhea and pseudomembraneous colitis. Lethal toxin is involved in toxic shock syndrome after abortion and α-toxin in gas gangrene development. CGTs enter cells via receptor-mediated endocytosis and require an ...

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. Plant Insecticidal Toxins in Ecological Networks

    Directory of Open Access Journals (Sweden)

    Sébastien Ibanez

    2012-04-01

    Full Text Available Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects’ vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  19. Toxin-Antitoxin Battle in Bacteria

    DEFF Research Database (Denmark)

    Cataudella, Ilaria

    This PhD thesis consists of three research projects revolving around the common thread of investigation of the properties and biological functions of Toxin-Antitoxin loci. Toxin-Antitoxin (TA) loci are transcriptionally regulated via an auto-inhibition mechanism called conditional cooperativity, ...

  20. Target-Driven Evolution of Scorpion Toxins.

    Science.gov (United States)

    Zhang, Shangfei; Gao, Bin; Zhu, Shunyi

    2015-01-01

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact with two adjacent loops in the voltage-sensor domain (DIV) of sodium channels, as validated by our newly constructed computational model of toxin-channel complex. Despite the lack of positive selection signals in these two loops, they accumulated extensive sequence variations by relaxed purifying selection in prey and predators of scorpions. The evolutionary variability in the toxin-bound regions of sodium channels indicates that accelerated substitutions in the multigene family of scorpion toxins is a consequence of dealing with the target diversity. This work presents an example of atypical co-evolution between animal toxins and their molecular targets, in which toxins suffered from more prominent selective pressure from the channels of their competitors. Our discovery helps explain the evolutionary rationality of gene duplication of toxins in a specific venomous species. PMID:26444071

  1. The Ins and Outs of Anthrax Toxin.

    Science.gov (United States)

    Friebe, Sarah; van der Goot, F Gisou; Bürgi, Jérôme

    2016-03-01

    Anthrax is a severe, although rather rare, infectious disease that is caused by the Gram-positive, spore-forming bacterium Bacillus anthracis. The infectious form is the spore and the major virulence factors of the bacterium are its poly-γ-D-glutamic acid capsule and the tripartite anthrax toxin. The discovery of the anthrax toxin receptors in the early 2000s has allowed in-depth studies on the mechanisms of anthrax toxin cellular entry and translocation from the endocytic compartment to the cytoplasm. The toxin generally hijacks the endocytic pathway of CMG2 and TEM8, the two anthrax toxin receptors, in order to reach the endosomes. From there, the pore-forming subunit of the toxin inserts into endosomal membranes and enables translocation of the two catalytic subunits. Insertion of the pore-forming unit preferentially occurs in intraluminal vesicles rather than the limiting membrane of the endosome, leading to the translocation of the enzymatic subunits in the lumen of these vesicles. This has important consequences that will be discussed. Ultimately, the toxins reach the cytosol where they act on their respective targets. Target modification has severe consequences on cell behavior, in particular on cells of the immune system, allowing the spread of the bacterium, in severe cases leading to host death. Here we will review the literature on anthrax disease with a focus on the structure of the toxin, how it enters cells and its immunological effects. PMID:26978402

  2. Stealth and mimicry by deadly bacterial toxins

    DEFF Research Database (Denmark)

    Yates, S.P.; Jørgensen, Rene; Andersen, Gregers Rom;

    2006-01-01

    Diphtheria toxin and exotoxin A are well-characterized members of the ADP-ribosyltransferase toxin family that serve as virulence factors in the pathogenic bacteria, Corynebacterium diphtheriae and Pseudomonas aeruginosa.  New high-resolution structural data of the Michaelis complex of the...

  3. 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

  4. 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 of...

  5. Molecular Characterization of Epidemic Isolates of Vibrio Cholerae O1 by Arbitrarily Primed PCR (AP-PCR

    Directory of Open Access Journals (Sweden)

    M Izadi

    2008-07-01

    Full Text Available Background: Epidemic and endemic cholera is a major public health problem for many countries. Aim of this study was to evaluate AP-PCR for investigation of clonal relatedness among the strains of Vibrio cholerae recovered from an outbreak occurred in different parts of Iran in 2005. Methods: The study was conducted during the cholera outbreak occurred in some of provinces in Iran in summer 2005. Bacterial isolation and identification was carried out according to the standard bacteriological methods. Arbitrarily primed PCR (AP-PCR used to study the genetic relatedness between the V.cholerae isolates. Results: Thirty-nine isolates of V.cholerae O1 were identified. All isolates belonged to serotype Inaba. AP-PCR could differentiate the isolates into five groups. AP-PCR cluster types 1 and 2 were the most prevalent groups, accounting for 36% and 41%, respectively, of V.cholerae isolates. Conclusion: The most of epidemic strains of V.cholerae O1 isolated in the year 2005 could be attributed to two predominant clusters including AP-PCR cluster types 1 and 2 accounting for more than 77% of isolates. In conclusion, a few epidemic clones were responsible for the apparently epidemic occurrence of cholera in provinces studied.

  6. 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 water) decrease in water availability in the basin increased odds of above normal cholera by 24% (confidence interval [CI] = 20-31%; P water by 1 unit, through floods, increased odds of above average cholera in the autumn by 29% (CI = 22-33%; P < 0.05). PMID:26526921

  7. 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.

  8. 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

  9. 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 ...

  10. Brown spider dermonecrotic toxin directly induces nephrotoxicity

    International Nuclear Information System (INIS)

    Brown spider (Loxosceles genus) venom can induce dermonecrotic lesions at the bite site and systemic manifestations including fever, vomiting, convulsions, disseminated intravascular coagulation, hemolytic anemia and acute renal failure. The venom is composed of a mixture of proteins with several molecules biochemically and biologically well characterized. The mechanism by which the venom induces renal damage is unknown. By using mice exposed to Loxosceles intermedia recombinant dermonecrotic toxin (LiRecDT), we showed direct induction of renal injuries. Microscopic analysis of renal biopsies from dermonecrotic toxin-treated mice showed histological alterations including glomerular edema and tubular necrosis. Hyalinization of tubules with deposition of proteinaceous material in the tubule lumen, tubule epithelial cell vacuoles, tubular edema and epithelial cell lysis was also observed. Leukocytic infiltration was neither observed in the glomerulus nor the tubules. Renal vessels showed no sign of inflammatory response. Additionally, biochemical analyses showed such toxin-induced changes in renal function as urine alkalinization, hematuria and azotemia with elevation of blood urea nitrogen levels. Immunofluorescence with dermonecrotic toxin antibodies and confocal microscopy analysis showed deposition and direct binding of this toxin to renal intrinsic structures. By immunoblotting with a hyperimmune dermonecrotic toxin antiserum on renal lysates from toxin-treated mice, we detected a positive signal at the region of 33-35 kDa, which strengthens the idea that renal failure is directly induced by dermonecrotic toxin. Immunofluorescence reaction with dermonecrotic toxin antibodies revealed deposition and binding of this toxin directly in MDCK epithelial cells in culture. Similarly, dermonecrotic toxin treatment caused morphological alterations of MDCK cells including cytoplasmic vacuoles, blebs, evoked impaired spreading and detached cells from each other and from

  11. The toxin component of targeted anti-tumor toxins determines their efficacy increase by saponins.

    Science.gov (United States)

    Weng, Alexander; Thakur, Mayank; Beceren-Braun, Figen; Bachran, Diana; Bachran, Christopher; Riese, Sebastian B; Jenett-Siems, Kristina; Gilabert-Oriol, Roger; Melzig, Matthias F; Fuchs, Hendrik

    2012-06-01

    Tumor-targeting protein toxins are composed of a toxic enzyme coupled to a specific cell binding domain that targets cancer-associated antigens. The anti-tumor treatment by targeted toxins is accompanied by dose-limiting side effects. The future prospects of targeted toxins for therapeutic use in humans will be determined by reduce side effects. Certain plant secondary metabolites (saponins) were shown to increase the efficacy of a particular epidermal growth factor receptor (EGFR)-targeted toxin, paralleled by a tremendous decrease of side effects. This study was conducted in order to investigate the effects of substituting different toxin moieties fused to an EGF ligand binding domain on the augmentative ability of saponins for each against therapeutic potential of the saponin-mediated efficacy increase for different anti-tumor toxins targeting the EGFR. We designed several EGFR-targeted toxins varying in the toxic moiety. Each targeted toxin was used in combination with a purified saponin (SA1641), isolated from the ornamental plant Gypsophila paniculata L. SA1641 was characterized and the SA1641-mediated efficacy increase was investigated on EGFR-transfected NIH-3T3 cells. We observed a high dependency of the SA1641-mediated efficacy increase on the nature of toxin used for the construction of the targeted toxin, indicating high specificity. Structural alignments revealed a high homology between saporin and dianthin-30, the two toxic moieties that benefit most from the combination with SA1641. We further demonstrate that SA1641 did not influence the plasma membrane permeability, indicating an intracellular interaction of SA1641 and the toxin components of targeted toxins. Surface plasmon resonance measurements point to a transient binding of SA1641 to the toxin components of targeted toxins. PMID:22309811

  12. Interplay between toxin transport and flotillin localization

    DEFF Research Database (Denmark)

    Pust, Sascha; Dyve, Anne Berit; Torgersen, Maria L; van Deurs, Bo; Sandvig, Kirsten

    2010-01-01

    for flotillin-1 or -2. However, the Golgi-dependent sulfation of both toxins was significantly reduced in flotillin knockdown cells. Interestingly, when the transport of ricin to the ER was investigated, we obtained an increased mannosylation of ricin in flotillin-1 and flotillin-2 knockdown cells....... The toxicity of both toxins was twofold increased in flotillin-depleted cells. Since BFA (Brefeldin A) inhibits the toxicity even in flotillin knockdown cells, the retrograde toxin transport is apparently still Golgi-dependent. Thus, flotillin proteins regulate and facilitate the retrograde transport......The flotillin proteins are localized in lipid domains at the plasma membrane as well as in intracellular compartments. In the present study, we examined the importance of flotillin-1 and flotillin-2 for the uptake and transport of the bacterial Shiga toxin (Stx) and the plant toxin ricin and we...

  13. Immunotoxins: The Role of the Toxin

    Directory of Open Access Journals (Sweden)

    David FitzGerald

    2013-08-01

    Full Text Available Immunotoxins are antibody-toxin bifunctional molecules that rely on intracellular toxin action to kill target cells. Target specificity is determined via the binding attributes of the chosen antibody. Mostly, but not exclusively, immunotoxins are purpose-built to kill cancer cells as part of novel treatment approaches. Other applications for immunotoxins include immune regulation and the treatment of viral or parasitic diseases. Here we discuss the utility of protein toxins, of both bacterial and plant origin, joined to antibodies for targeting cancer cells. Finally, while clinical goals are focused on the development of novel cancer treatments, much has been learned about toxin action and intracellular pathways. Thus toxins are considered both medicines for treating human disease and probes of cellular function.

  14. Botulinum toxin in poststroke spasticity.

    Science.gov (United States)

    Ozcakir, Suheda; Sivrioglu, Koncuy

    2007-06-01

    Poststroke hemiparesis, together with abnormal muscle tone, is a major cause of morbidity and disability. Although most hemiparetic patients are able to reach different ambulatory levels with rehabilitation efforts, upper and lower limb spasticity can impede activities of daily living, personal hygiene, ambulation and, in some cases, functional improvement. The goals of spasticity management include increasing mobility and range of motion, attaining better hygiene, improving splint wear and other functional activities. Conservative measures, such as positioning, stretching and exercise are essential in spasticity management, but alone often are inadequate to effectively control it. Oral antispastic medications often provide limited effects with short duration and frequent unwanted systemic side effects, such as weakness, sedation and dry mouth. Therefore, neuromuscular blockade by local injections have become the first choice for the treatment of focal spasticity, particularly in stroke patients. Botulinum toxin (BTX), being one of the most potent biological toxins, acts by blocking neuromuscular transmission via inhibiting acetylcholine release. Currently, focal spasticity is being treated successfully with BTX via injecting in the spastic muscles. Two antigenically distinct serotypes of BTX are available on the market as type A and B. Clinical studies of BTX used for spastic hemiplegic patients are reviewed in this article in two major categories, upper and lower limb applications. This review addresses efficacy in terms of outcome measures, such as muscle tone reduction and functional outcome, as well as safety issues. Application modifications of dose, dilutions, site of injections and combination therapies with BTX injections are also discussed. PMID:17607049

  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

    to climate change are shown to be in the range of 0.32 to 1.4 percent of GDP in Tanzania 2030. The results provide useful insights into national-level estimates of the implications of climate change on the health sector and offer information which can feed into both national and international debates......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...... 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. 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.

  17. 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.

  18. 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)

  19. 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)

  20. Afferent projections to the hamster intergeniculate leaflet demonstrated by retrograde and anterograde tracing

    DEFF Research Database (Denmark)

    Vrang, Niels; Mrosovsky, N.; Mikkelsen, Jens D.

    2003-01-01

    Circadian rhythms, Suprachiasmatic nucleus, Cholera toxin B, Phaseolus vulgaris-leucoagglutinin, Nonphotic......Circadian rhythms, Suprachiasmatic nucleus, Cholera toxin B, Phaseolus vulgaris-leucoagglutinin, Nonphotic...

  1. Roles of Anthrax Toxin Receptor 2 in Anthrax Toxin Membrane Insertion and Pore Formation

    Directory of Open Access Journals (Sweden)

    Jianjun Sun

    2016-01-01

    Full Text Available Interaction between bacterial toxins and cellular surface receptors is an important component of the host-pathogen interaction. Anthrax toxin protective antigen (PA binds to the cell surface receptor, enters the cell through receptor-mediated endocytosis, and forms a pore on the endosomal membrane that translocates toxin enzymes into the cytosol of the host cell. As the major receptor for anthrax toxin in vivo, anthrax toxin receptor 2 (ANTXR2 plays an essential role in anthrax toxin action by providing the toxin with a high-affinity binding anchor on the cell membrane and a path of entry into the host cell. ANTXR2 also acts as a molecular clamp by shifting the pH threshold of PA pore formation to a more acidic pH range, which prevents premature pore formation at neutral pH before the toxin reaches the designated intracellular location. Most recent studies have suggested that the disulfide bond in the immunoglobulin (Ig-like domain of ANTXR2 plays an essential role in anthrax toxin action. Here we will review the roles of ANTXR2 in anthrax toxin action, with an emphasis on newly updated knowledge.

  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. 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

  5. On Spatially Explicit Models of Epidemic and Endemic Cholera: The Haiti and Lake Kivu Case Studies.

    Science.gov (United States)

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

    2014-12-01

    The first part of the Lecture deals with the predictive ability of mechanistic models for the Haitian cholera epidemic. Predictive models of epidemic cholera need to resolve at suitable aggregation levels spatial data pertaining to local communities, epidemiological records, hydrologic drivers, waterways, patterns of human mobility and proxies of exposure rates. A formal model comparison framework provides a quantitative assessment of the explanatory and predictive abilities of various model settings with different spatial aggregation levels. Intensive computations and objective model comparisons show that parsimonious spatially explicit models accounting for spatial connections have superior explanatory power than spatially disconnected ones for short-to intermediate calibration windows. In general, spatially connected models show better predictive ability than disconnected ones. We suggest limits and validity of the various approaches and discuss the pathway towards the development of case-specific predictive tools in the context of emergency management. The second part deals with approaches suitable to describe patterns of endemic cholera. Cholera outbreaks have been reported in the Democratic Republic of the Congo since the 1970s. Here we employ a spatially explicit, inhomogeneous Markov chain model to describe cholera incidence in eight health zones on the shore of lake Kivu. Remotely sensed datasets of chlorophyll a concentration in the lake, precipitation and indices of global climate anomalies are used as environmental drivers in addition to baseline seasonality. The effect of human mobility is also modelled mechanistically. We test several models on a multi-year dataset of reported cholera cases. Fourteen models, accounting for different environmental drivers, are selected in calibration. Among these, the one accounting for seasonality, El Nino Southern Oscillation, precipitation and human mobility outperforms the others in cross-validation.

  6. High depth, whole-genome sequencing of cholera isolates from Haiti and the Dominican Republic

    Directory of Open Access Journals (Sweden)

    Sealfon Rachel

    2012-09-01

    Full Text Available Abstract Background Whole-genome sequencing is an important tool for understanding microbial evolution and identifying the emergence of functionally important variants over the course of epidemics. In October 2010, a severe cholera epidemic began in Haiti, with additional cases identified in the neighboring Dominican Republic. We used whole-genome approaches to sequence four Vibrio cholerae isolates from Haiti and the Dominican Republic and three additional V. cholerae isolates to a high depth of coverage (>2000x; four of the seven isolates were previously sequenced. Results Using these sequence data, we examined the effect of depth of coverage and sequencing platform on genome assembly and identification of sequence variants. We found that 50x coverage is sufficient to construct a whole-genome assembly and to accurately call most variants from 100 base pair paired-end sequencing reads. Phylogenetic analysis between the newly sequenced and thirty-three previously sequenced V. cholerae isolates indicates that the Haitian and Dominican Republic isolates are closest to strains from South Asia. The Haitian and Dominican Republic isolates form a tight cluster, with only four variants unique to individual isolates. These variants are located in the CTX region, the SXT region, and the core genome. Of the 126 mutations identified that separate the Haiti-Dominican Republic cluster from the V. cholerae reference strain (N16961, 73 are non-synonymous changes, and a number of these changes cluster in specific genes and pathways. Conclusions Sequence variant analyses of V. cholerae isolates, including multiple isolates from the Haitian outbreak, identify coverage-specific and technology-specific effects on variant detection, and provide insight into genomic change and functional evolution during an epidemic.

  7. 安徽省淮南市首起0139霍乱弧菌疫情检测分析%Experimental analysis the first cases of cholera epidemic detection of 0139 of Huainan

    Institute of Scientific and Technical Information of China (English)

    余寿杰; 刘笑梅; 曹敏; 胡守奎; 胡万富

    2011-01-01

    Objective To identify the first cases of cholera in Huainan,0139 epidemic causes and biological properties. Methods Conventional methods of serological and bacteriological methods of the strains were identified by polymerase chain reaction (PCR) to detect cholera virulence genes, susceptibility testing modified KB.Results 1 ,was isolated and serum agglutination results,2 patients were all positive stool samples,6 were in close contact with all the negative rectal swab;turtle pond-like 18,5 were positive;turtle egg in battle were like 9,2 were positive ; turtle eggs 7, the positive three copies; turtle waste 11, were negative. 2, or more positive culture drug sensitivity test of the pioneer B, doxycycline resistant; to ampicillin, tetracycline in sensitive;on norfloxacin, gentamicin, ciprofloxacin sensitive. 3,or more positive cultures gene DNA PCR test results,cholera toxin(CT) ,toxin coregulated pilus (TCP) all were positive. Conclusion From the outbreak of cholera 0139 is water pollution caused by turtle ponds,The trip types of 0139 Vibrio cholera were highly homologous with that isolated from green turtle;the bacteria of the pioneer B, doxycycline resistance and carrying cta, tcpa virulence genes.%目的 探讨淮南市首起0139霍乱弧菌疫情的发生原因和生物学特性。方法 血清学及常规细菌学方法对菌株进行鉴定,聚合酶链式反应(PCR)检测霍乱毒力基因,改良K-B药敏实验。结果 (1)培养分离及血清凝集试验结果,2例患者粪便标本全部阳性,密切接触者6人肛拭子全部阴性;甲鱼塘水样18份,阳性5份;甲鱼产蛋沙场样9份,2份阳性;甲鱼蛋7份,阳性3份;甲鱼排泄物11份,均为阴性。(2)血清凝集试验阳性培养物对头孢哌酮、强力霉素耐药;对氨苄西林、四环素中敏;对氟哌酸、庆大霉素、环丙沙星等敏感。(3)血清凝集试验阳性培养物霍乱毒素(CT)、毒素协同调节菌毛(TCP)全部阳性。结论

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

    OpenAIRE

    John Yew Huat Tang; Bariah Ibrahim Izenty; Ahmad Juanda Nur’ Izzati; Siti Rahmah Masran; Chew Chieng Yeo; Arshad Roslan; Che Abdullah Abu Bakar

    2013-01-01

    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 ag...

  9. 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 of...... V. cholerae that were able to survive the deletion of dam. In these mutants, homologous recombination and chromosome dimer resolution are essential, unless DNA mismatch repair is inactivated. Furthermore, the initiator of chr2 replication, RctB, is no longer required. We show that, instead...

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

    OpenAIRE

    Javad Alizadeh; Reza Ranjbar; Mehdi Kamali; Nima Farhadi; Amin Davari; Nourkhoda Sadeghifard

    2013-01-01

    Background and Objective 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. Materials and Methods A gene encoding ompW was cloned into the Ppicza vector downstream of alcohol oxidase promoter. Then recom...

  11. 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)

  12. Treatment of Cholera with Hydrotherapy by Lanaras: A Page from History

    OpenAIRE

    Emmanuel Katsogridakis

    2011-01-01

    Cholera is reemerging as a major public health concern in rural areas. The advances in our understanding of the pathophysiology and treatment of this disease have enriched the clinicians’ therapeutic armamentarium. Treatment of cholera however, was not always effective or straightforward. In this article we present the use of the controversial treatment of hydrotherapy, as described in the book Mémoire sur le Choléra Asiatique de 1894 à Samsoun by Dr. C. Lanaras. Klimik Dergisi 2011; 24(2): 8...

  13. Cyanobacterial toxins: risk management for health protection

    International Nuclear Information System (INIS)

    This paper reviews the occurrence and properties of cyanobacterial toxins, with reference to the recognition and management of the human health risks which they may present. Mass populations of toxin-producing cyanobacteria in natural and controlled waterbodies include blooms and scums of planktonic species, and mats and biofilms of benthic species. Toxic cyanobacterial populations have been reported in freshwaters in over 45 countries, and in numerous brackish, coastal, and marine environments. The principal toxigenic genera are listed. Known sources of the families of cyanobacterial toxins (hepato-, neuro-, and cytotoxins, irritants, and gastrointestinal toxins) are briefly discussed. Key procedures in the risk management of cyanobacterial toxins and cells are reviewed, including derivations (where sufficient data are available) of tolerable daily intakes (TDIs) and guideline values (GVs) with reference to the toxins in drinking water, and guideline levels for toxigenic cyanobacteria in bathing waters. Uncertainties and some gaps in knowledge are also discussed, including the importance of exposure media (animal and plant foods), in addition to potable and recreational waters. Finally, we present an outline of steps to develop and implement risk management strategies for cyanobacterial cells and toxins in waterbodies, with recent applications and the integration of Hazard Assessment Critical Control Point (HACCP) principles

  14. In silico analysis of putative paralytic shellfish poisoning toxins export proteins in cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Katia Soto-Liebe

    Full Text Available Paralytic shellfish poisoning toxins (PSTs are a family of more than 30 natural alkaloids synthesized by dinoflagellates and cyanobacteria whose toxicity in animals is mediated by voltage-gated Na(+ channel blocking. The export of PST analogues may be through SxtF and SxtM, two putative MATE (multidrug and toxic compound extrusion family transporters encoded in PSTs biosynthetic gene cluster (sxt. sxtM is present in every sxt cluster analyzed; however, sxtF is only present in the Cylindrospermopsis-Raphidiopsis clade. These transporters are energetically coupled with an electrochemical gradient of proton (H(+ or sodium (Na(+ ions across membranes. Because the functional role of PSTs remains unknown and methods for genetic manipulation in PST-producing organisms have not yet been developed, protein structure analyses will allow us to understand their function. By analyzing the sxt cluster of eight PST-producing cyanobacteria, we found no correlation between the presence of sxtF or sxtM and a specific PSTs profile. Phylogenetic analyses of SxtF/M showed a high conservation of SxtF in the Cylindrospermopsis-Raphidiopsis clade, suggesting conserved substrate affinity. Two domains involved in Na(+ and drug recognition from NorM proteins (MATE family of Vibrio parahaemolyticus and V. cholerae are present in SxtF/M. The Na(+ recognition domain was conserved in both SxtF/M, indicating that Na(+ can maintain the role as a cation anti-transporter. Consensus motifs for toxin binding differed between SxtF and SxtM implying differential substrate binding. Through protein modeling and docking analysis, we found that there is no marked affinity between the recognition domain and a specific PST analogue. This agrees with our previous results of PST export in R. brookii D9, where we observed that the response to Na(+ incubation was similar to different analogues. These results reassert the hypothesis regarding the involvement of Na(+ in toxin export, as well as

  15. In Silico Analysis of Putative Paralytic Shellfish Poisoning Toxins Export Proteins in Cyanobacteria

    Science.gov (United States)

    Soto-Liebe, Katia; López-Cortés, Xaviera A.; Fuentes-Valdes, Juan José; Stucken, Karina; Gonzalez-Nilo, Fernando; Vásquez, Mónica

    2013-01-01

    Paralytic shellfish poisoning toxins (PSTs) are a family of more than 30 natural alkaloids synthesized by dinoflagellates and cyanobacteria whose toxicity in animals is mediated by voltage-gated Na+ channel blocking. The export of PST analogues may be through SxtF and SxtM, two putative MATE (multidrug and toxic compound extrusion) family transporters encoded in PSTs biosynthetic gene cluster (sxt). sxtM is present in every sxt cluster analyzed; however, sxtF is only present in the Cylindrospermopsis-Raphidiopsis clade. These transporters are energetically coupled with an electrochemical gradient of proton (H+) or sodium (Na+) ions across membranes. Because the functional role of PSTs remains unknown and methods for genetic manipulation in PST-producing organisms have not yet been developed, protein structure analyses will allow us to understand their function. By analyzing the sxt cluster of eight PST-producing cyanobacteria, we found no correlation between the presence of sxtF or sxtM and a specific PSTs profile. Phylogenetic analyses of SxtF/M showed a high conservation of SxtF in the Cylindrospermopsis-Raphidiopsis clade, suggesting conserved substrate affinity. Two domains involved in Na+ and drug recognition from NorM proteins (MATE family) of Vibrio parahaemolyticus and V. cholerae are present in SxtF/M. The Na+ recognition domain was conserved in both SxtF/M, indicating that Na+ can maintain the role as a cation anti-transporter. Consensus motifs for toxin binding differed between SxtF and SxtM implying differential substrate binding. Through protein modeling and docking analysis, we found that there is no marked affinity between the recognition domain and a specific PST analogue. This agrees with our previous results of PST export in R. brookii D9, where we observed that the response to Na+ incubation was similar to different analogues. These results reassert the hypothesis regarding the involvement of Na+ in toxin export, as well as the motifs L398XGLQD

  16. The Enterotoxicity of Clostridium difficile Toxins

    OpenAIRE

    Hanping Feng; Tor Savidge; Xingmin Sun

    2010-01-01

    The major virulence factors of Clostridium difficile infection (CDI) are two large exotoxins A (TcdA) and B (TcdB). However, our understanding of the specific roles of these toxins in CDI is still evolving. It is now accepted that both toxins are enterotoxic and proinflammatory in the human intestine. Both purified TcdA and TcdB are capable of inducing the pathophysiology of CDI, although most studies have focused on TcdA. C. difficile toxins exert a wide array of biological activities by act...

  17. Identification of Critical Amino Acids Conferring Lethality in VopK, a Type III Effector Protein of Vibrio cholerae: Lessons from Yeast Model System.

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    Leela Krishna Bankapalli

    Full Text Available VopK, a type III effector protein, has been implicated in the pathogenesis of Vibrio cholerae strains belonging to diverse serogroups. Ectopic expression of this protein exhibits strong toxicity in yeast model system. In order to map critical residues in VopK, we scanned the primary sequence guided by available data on various toxins and effector proteins. Our in silico analysis of VopK indicated the presence of predicted MCF1-SHE (SHxxxE serine peptidase domain at the C-terminus region of the protein. Substitution of each of the predicted catalytic triad residues namely Ser314, His353 and Glu357 with alanine resulted in recombinant VopK proteins varying in lethality as evaluated in yeast model system. We observed that replacement of glutamate357 to alanine causes complete loss in toxicity while substitutions of serine314 and histidine353 with alanine exhibited partial loss in toxicity without affecting the stability of variants. In addition, replacement of another conserved serine residue at position 354 (S354 within predicted S314H353E357 did not affect toxicity of VopK. In essence, combined in silico and site directed mutagenesis, we have identified critical amino acids contributing to the lethal activity of VopK in yeast model system.

  18. Complete topology of the RNF complex from Vibrio cholerae.

    Science.gov (United States)

    Hreha, Teri N; Mezic, Katherine G; Herce, Henry D; Duffy, Ellen B; Bourges, Anais; Pryshchep, Sergey; Juarez, Oscar; Barquera, Blanca

    2015-04-21

    RNF is a redox-driven ion (Na(+) and in one case possibly H(+)) transporter present in many prokaryotes. It has been proposed that RNF performs a variety of reactions in different organisms, delivering low-potential reducing equivalents for specific cellular processes. RNF shares strong homology with the Na(+)-pumping respiratory enzyme Na(+)-NQR, although there are significant differences in subunit and redox cofactor composition. Here we report a topological analysis of the six subunits of RNF from Vibrio cholerae. Although individual subunits from other organisms have previously been studied, this is the first complete, experimentally derived, analysis of RNF from any one source. This has allowed us to identify and confirm key properties of RNF. The putative NADH binding site in RnfC is located on the cytoplasmic side of the membrane. FeS centers in RnfB and RnfC are also located on the cytoplasmic side. However, covalently attached FMNs in RnfD and RnfG are both located in the periplasm. RNF also contains a number of acidic residues that correspond to functionally important groups in Na(+)-NQR. The acidic residues involved in Na(+) uptake and many of those implicated in Na(+) translocation are topologically conserved. The topology of RNF closely matches the topology represented in the newly published structure of Na(+)-NQR, consistent with the close relation between the two enzymes. The topology of RNF is discussed in the context of the current structural model of Na(+)-NQR, and the proposed functionality of the RNF complex itself. PMID:25831459

  19. Binding and uptake of diphtheria toxin by toxin-resistant Chinese hamster ovary and mouse cells.

    OpenAIRE

    Didsbury, J R; Moehring, J M; Moehring, T. J.

    1983-01-01

    We investigated two phenotypically distinct types of diphtheria toxin-resistant mutants of Chinese hamster cells and compared their resistance with that of naturally resistant mouse cells. All are resistant due to a defect in the process of internalization and delivery of toxin to its target in the cytosol, elongation factor 2. By cell hybridization studies, analysis of cross-resistance, and determination of specific binding sites for 125I-labeled diphtheria toxin, we showed that these cell s...

  20. Assessing the knowledge, attitudes and practices regarding cholera preparedness and prevention in Ga-Mampuru village, Limpopo, South Africa

    Directory of Open Access Journals (Sweden)

    Alice Ncube

    2016-01-01

    Full Text Available The study assessed the knowledge, attitudes and practices of cholera prevention and preparedness in Ga-Mampuru village (Limpopo, South Africa. Interviewers collected data using a two-pronged method, namely a household questionnaire (open- and closed-ended questions to assess knowledge and attitudes about cholera and observations to assess practices in the prevention and management of the disease. Additionally, interviewers took pictures with the respondents’ permission. Ninety-six respondents were interviewed. Most respondents (86% indicated they knew how cholera was contracted with 84% indicating contaminated water as a source. Ninety percent of the respondents indicated they knew how to prevent contracting cholera. All respondents generally knew that cholera could be treated with medicine received at a health-care facility or worker. Fewer respondents (58% had specific knowledge such as the use of rehydration solutions. The respondents’ high level of prevention practices could be biased. Interviewers observed that many practices were not adhered to, like not washing hands, not using toilet paper and throwing waste in respondents’ yards. Therefore, the community of Ga-Mampuru had not reached a stage of adequate cholera prevention and preparedness in spite of the fact that they were aware of cholera risks and risk-reduction measures.