Genetic relatedness of selected clinical Vibrio cholerae O139 isolates from the southern coastal area of China over a 20-year period.

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Li, B S; Xiao, Y; Wang, D C; Tan, H L; Ke, B X; He, D M; Ke, C W; Zhang, Y H

2016-09-01

Vibrio cholerae O139 emerged as a causative agent of epidemic cholera in 1992 in India and Bangladesh, and was subsequently reported in China in 1993. The genetic relatedness and molecular characteristics of V. cholerae O139 in Guangdong Province, located in the southern coastal area of China, remains undetermined. In this study, we investigated 136 clinical V. cholerae O139 isolates from 1993 to 2013 in Guangdong. By conventional PCR, 123 (90·4%) isolates were positive for ctxB, ace and zot. Sequencing of the positive amplicons indicated 113 (91·7%) isolates possessed the El Tor allele of ctxB (genotype 3); seven carried the classical ctxB type (genotype 1) and three harboured a novel ctxB type (genotype 5). With respect to tcpA, 123 (90·4%) isolates were positive for the El Tor allele. In addition, pulsed-field gel electrophoresis (with NotI digestion) differentiated the isolates into clusters A and B. Cluster A contained seven of the non-toxigenic isolates from 1998 to 2000; another six non-toxigenic isolates (from 1998 and 2007) and all of the toxigenic isolates formed cluster B. Our results suggest that over a 20-year period, the predominant O139 clinical isolates have maintained a relatively tight clonal structure, although some genetic variance and shift has occurred. Our data highlight the persistence of toxigenic V. cholerae O139 in clinical settings in the southern coastal area of China.

[Cytotoxic effect of Vibrio cholerae non-O1 on Vero cells].

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Figueroa-Arredondo, P; García-Lozano, H; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

1994-01-01

At the present time there is still in Mexico a diarrhoeal outbreak due to Vibrio cholerae O1. In INDRE we have isolated from the same outbreak last year (jan-apr), 70 strains of Vibrio cholerae Non-O1. These were isolated from patients with a diarrhoeal illness different from cholera. Patients were of different ages and sex, and from various geographic areas. The isolated strains were confirmed by serological agglutination test with polyclonal antisera, and they neither belong to O1 serogroup or O139. We assayed all the 70 strains in Vero cells, searching for cytotoxic effect, probably attributed to cholera toxin, or any other toxin. The strains were screened by PCR for cholera toxin gene detection, and negative results were obtained. We have found only one CT-producer strain, but it was a rough one so, we are not able to affirm that is not a V. cholerae O1 serotype. Vibrio cholerae Non-O1 strains, tested in Vero cells assay, produced cytotoxic effect within 24 h. It was found that 48/70 strains (66.6%), had cytotoxic activity, showing rounding and then lysis of cells. From our results we concluded that this cytotoxic effect, is not cholera toxin related, instead we propose it could be due to an unknown virulence factor, probably a different toxin in mexican Vibrio cholerae Non-O1 strains.

Immunogenicity of a killed bivalent (O1 and O139 whole cell oral cholera vaccine, Shanchol, in Haiti.

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Richelle C Charles

2014-05-01

Full Text Available Studies of the immunogenicity of the killed bivalent whole cell oral cholera vaccine, Shanchol, have been performed in historically cholera-endemic areas of Asia. There is a need to assess the immunogenicity of the vaccine in Haiti and other populations without historical exposure to Vibrio cholerae.We measured immune responses after administration of Shanchol, in 25 adults, 51 older children (6-17 years, and 47 younger children (1-5 years in Haiti, where cholera was introduced in 2010. A≥4-fold increase in vibriocidal antibody titer against V. cholerae O1 Ogawa was observed in 91% of adults, 74% of older children, and 73% of younger children after two doses of Shanchol; similar responses were observed against the Inaba serotype. A≥2-fold increase in serum O-antigen specific polysaccharide IgA antibody levels against V. cholerae O1 Ogawa was observed in 59% of adults, 45% of older children, and 61% of younger children; similar responses were observed against the Inaba serotype. We compared immune responses in Haitian individuals with age- and blood group-matched individuals from Bangladesh, a historically cholera-endemic area. The geometric mean vibriocidal titers after the first dose of vaccine were lower in Haitian than in Bangladeshi vaccinees. However, the mean vibriocidal titers did not differ between the two groups after the second dose of the vaccine.A killed bivalent whole cell oral cholera vaccine, Shanchol, is highly immunogenic in Haitian adults and children. A two-dose regimen may be important in Haiti, and other populations lacking previous repeated exposures to V. cholerae.

Water sources as reservoirs of Vibrio cholerae O1 and non-O1 strains in Bepanda, Douala (Cameroon): relationship between isolation and physico-chemical factors.

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Akoachere, Jane-Francis Tatah Kihla; Mbuntcha, Christelle Kwedjeu Pulcherie

2014-07-30

Cholera has been endemic in Douala since 1971. Most outbreaks start from Bepanda, an overcrowded neighbourhood with poor hygiene and sanitary conditions. We investigated water sources in Bepanda as reservoirs of Vibrio cholerae, the causative agent of cholera, determined its antibiotic susceptibility and some physico-chemical characteristics that could maintain the endemicity of this organism in Bepanda. Three hundred and eighteen water samples collected from 45 wells, 8 taps and 1 stream from February to July 2009 were analyzed for V. cholerae using standard methods. Isolates were characterized morphologically, biochemically and serologically. The disc diffusion technique was employed to investigate antibiotic susceptibility. Differences in prevalence of organism between seasons were analysed. Correlation strength and direction of association between physico-chemical parameters and occurrence of V. cholerae was analyzed using the Kendall tau_b non-parametric correlation. This was further confirmed with the forward-stepwise binary logistic regression. Eighty-seven (27.4%) samples were positive for V. cholerae. Isolation was highest from wells. The organism was isolated in the rainy season and dry season but the frequency of isolation was significantly higher (χ2 = 7.009, df = 1, P = 0.008) in the rainy season. Of the 96 confirmed V. cholerae isolates, 32 (33.3%) belonged to serogroup O1 and 64 (66.6%) were serogroup non-O1/non-O139. Isolates from tap (municipal water) were non-O1/non-O139 strains. Salinity had a significant positive correlation with isolation in the dry season (+0.267, P = 0.015) and rainy season (+0.223, P = 0.028). The forward-stepwise method of binary logistic regression indicated that as pH (Wald = 11.753, df = 1), P = 0.001) increased, odds of isolation of V. cholerae also increased (B = 1.297, S.E = 0.378, Exp(B) = 3.657). All isolates were sensitive to ciprofloxacin and ofloxacin. Multi-drug resistance was predominant among the non-O1/non-O

Genetic characterization of ØVC8 lytic phage for Vibrio cholerae O1.

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Solís-Sánchez, Alejandro; Hernández-Chiñas, Ulises; Navarro-Ocaña, Armando; De la Mora, Javier; Xicohtencatl-Cortes, Juan; Eslava-Campos, Carlos

2016-03-22

Epidemics and pandemics of cholera, a diarrheal disease, are attributed to Vibrio cholera serogroups O1 and O139. In recent years, specific lytic phages of V. cholera have been proposed to be important factors in the cyclic occurrence of cholera in endemic areas. However, the role and potential participation of lytic phages during long interepidemic periods of cholera in non-endemic regions have not yet been described. The purpose of this study was to isolate and characterize specific lytic phages of V. cholera O1 strains. Sixteen phages were isolated from wastewater samples collected at the Endhó Dam in Hidalgo State, Mexico, concentrated with PEG/NaCl, and purified by density gradient. The lytic activity of the purified phages was tested using different V. cholerae O1 and O139 strains. Phage morphology was visualized by transmission electron microscopy (TEM), and phage genome sequencing was performed using the Genome Analyzer IIx System. Genome assembly and bioinformatics analysis were performed using a set of high-throughput programs. Phage structural proteins were analyzed by mass spectrometry. Sixteen phages with lytic and lysogenic activity were isolated; only phage ØVC8 showed specific lytic activity against V. cholerae O1 strains. TEM images of ØVC8 revealed a phage with a short tail and an isometric head. The ØVC8 genome comprises linear double-stranded DNA of 39,422 bp with 50.8 % G + C. Of the 48 annotated ORFs, 16 exhibit homology with sequences of known function and several conserved domains. Bioinformatics analysis showed multiple conserved domains, including an Ig domain, suggesting that ØVC8 might adhere to different mucus substrates such as the human intestinal epithelium. The results suggest that ØVC8 genome utilize the "single-stranded cohesive ends" packaging strategy of the lambda-like group. The two structural proteins sequenced and analyzed are proteins of known function. ØVC8 is a lytic phage with specific activity against V. cholerae

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

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

2015-01-01

Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain, in order to identify novel genes potentially responsible for virulence. In this study, we compared the whole genome of the non-O1 PS15 strain to the whole genomes of toxigenic serotypes at the phylogenetic level, and found that the PS15 genome was distantly related to those of toxigenic V. cholerae. Thus we focused on a detailed gene comparison between PS15 and the distantly related O1 V. cholerae N16961. Based on sequence alignment we tentatively assigned chromosome numbers 1 and 2 to elements within the genome of non-O1 V. cholerae PS15. Further, we found that PS15 and O1 V. cholerae N16961 shared 98% identity and 766 genes, but of the genes present in N16961 that were missing in the non-O1 V. cholerae PS15 genome, 56 were predicted to encode not only for virulence–related genes (colonization, antimicrobial resistance, and regulation of persister cells) but also genes involved in the metabolic biosynthesis of lipids, nucleosides and sulfur compounds. Additionally, we found 113 genes unique to PS15 that were predicted to encode other properties related to virulence, disease, defense, membrane transport, and DNA metabolism. Here, we identified distinctive and novel genomic elements between O1 and non-O1 V. cholerae genomes as potential virulence factors and, thus, targets for future therapeutics. Modulation of such novel targets may eventually enhance eradication efforts of endemic and pandemic disease cholera in afflicted nations. PMID:25722857

Plasma and Mucosal Immunoglobulin M, Immunoglobulin A, and Immunoglobulin G Responses to the Vibrio cholerae O1 Protein Immunome in Adults With Cholera in Bangladesh.

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Charles, Richelle C; Nakajima, Rie; Liang, Li; Jasinskas, Al; Berger, Amanda; Leung, Daniel T; Kelly, Meagan; Xu, Peng; Kovác, Pavol; Giffen, Samantha R; Harbison, James D; Chowdhury, Fahima; Khan, Ashraful I; Calderwood, Stephen B; Bhuiyan, Taufiqur Rahman; Harris, Jason B; Felgner, Philip L; Qadri, Firdausi; Ryan, Edward T

2017-07-01

Cholera is a severe dehydrating illness of humans caused by toxigenic strains of Vibrio cholerae O1 or O139. Identification of immunogenic V. cholerae antigens could lead to a better understanding of protective immunity in human cholera. We probed microarrays containing 3652 V. cholerae antigens with plasma and antibody-in-lymphocyte supernatant (ALS, a surrogate marker of mucosal immune responses) from patients with severe cholera caused by V. cholerae O1 in Bangladesh and age-, sex-, and ABO-matched Bangladeshi controls. We validated a subset of identified antigens using enzyme-linked immunosorbent assay. Overall, we identified 608 immunoreactive V. cholerae antigens in our screening, 59 of which had higher immunoreactivity in convalescent compared with acute-stage or healthy control samples (34 in plasma, 39 in mucosal ALS; 13 in both sample sets). Identified antigens included cholera toxin B and A subunits, V. cholerae O-specific polysaccharide and lipopolysaccharide, toxin coregulated pilus A, sialidase, hemolysin A, flagellins (FlaB, FlaC, and FlaD), phosphoenolpyruvate-protein phosphotransferase, and diaminobutyrate-2-oxoglutarate aminotransferase. This study is the first antibody profiling of the mucosal and systemic antibody responses to the nearly complete V. cholerae O1 protein immunome; it has identified antigens that may aid in the development of an improved cholera vaccine. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Structural and Functional Annotation of Hypothetical Proteins of O139

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Md. Saiful Islam

2015-06-01

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

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

OpenAIRE

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

2014-01-01

Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain,...

The protective activity of tea against infection by Vibrio cholerae O1.

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Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Shimamura, T

1991-02-01

Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

A novel kit for rapid detection of Vibrio cholerae O1.

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Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

1994-01-01

We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bacterial strains, including both O1 and non-O1 serotypes of V. cholerae isolated from samples collected from a variety of geographical regions, were tested, and positive reactions were observed only with V. cholerae O1. Also, results of a field trial in Bangladesh, employing Cholera SMART, showed 100% specificity and 96% sensitivity compared with conventional culture methods. Another field trial, in Mexico, showed that Cholera SMART was 100% in agreement with a recently described coagglutination test when 108 stool specimens were tested.

Detection of viable and viable nonculturable Vibrio cholerae O1 through cultures and immunofluorescence in the Tucumán rivers, Argentina Detecção de Vibrio cholerae O1 viável e viável não cultivável, através de técnicas de cultivo e imunofluorescência nos rios de Tucumán, Argentina

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Olga Aulet

2007-08-01

Full Text Available Vibrio cholerae has been sporadically isolated from rivers in Tucumán, Argentina, since the outbreak in 1991. The aim of this study was to determine the environmental reservoir of the bacterium in these rivers, assessing the presence of Vibrio cholerae non-O1 and O1 (the latter both in its viable culturable and non culturable state and its relationship to environmental physicochemical variables. 18 water samplings were collected in the Salí River (in Canal Norte and Banda and the Lules River between 2003 and 2005. Physical-chemical measurements (pH, water temperature, electrical conductivity and dissolved oxygen were examined. Vibrio cholerae was investigated with conventional culture methods and with Direct Immunofluorescence (DFA-VNC in order to detect viable non culturable organisms. All isolated microorganisms corresponded to Vibrio cholerae non-O1 and non-O139 (Lules 26%, Canal Norte 33% and Banda 41%. The majority was found during spring and summer and correlated with temperature and pH. Non culturable Vibrio cholerae O1 was detected year round in 38 of the 54 water samples analyzed. Application of the Pearson correlation coefficient revealed that there was no relationship between positive immunofluorescence results and environmental physicochemical parameters. Genes coding for somatic antigen O1 were confirmed in all DFA-VNC-positive samples, whereas the virulence-associated ctxA and tcpA genes were confirmed in 24 samples.Vibrio cholerae tem sido isolado esporadicamente nos rios da Província de Tucumán, Argentina, desde outubro de 1991. O objetivo deste estudo foi localizar os reservatórios nestes rios, identificar a presença de Vibrio cholerae O1 (em estado cultivável e não cultivável e relacionar a presença desta bactéria com as variações físico-químicos da água. Foram coletadas dezoito amostras de água do rio Salí (nas localidades de Canal Norte e Banda e do rio Lules, entre 2003 e 2005. Estas foram submetidas a an

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

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Fátima Reyes-López

2015-08-01

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

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras Radiosensibility of Vibrio cholerae o1 incorporated in oysters, to 60CO

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Ivany R de Moraes

2000-02-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Canan��ia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.OBJECTIVE: Evaluate the effect of ionizing irradiation by 60Co on Vibrio cholerae O1, El-Tor, Ogawa, non-toxigenic, incorporated in live oysters Crassostrea brasiliana. METHODS: Samples of oysters were selected from Cananéia town in the South coast of S. Paulo state, Brazil, contaminated with Vibrio cholerae and irradiated with 60Co at 0.5 and 1.0 kGy dosages. RESULTS: Showed significant reductions of the initial number of V. cholerae , ranging from 3.4 x10(7 to 10³ and 10², respectively. The D10 values related with the respective doses of irradiation were 0.173 and 0.235. CONCLUSION: Considering a 6 value as safety factor, it is concluded that 1.41 kGy irradiation dosage is necessary to eliminate a high number of V. cholerae viable cells in oysters. Controls were used in the experiment.

A novel kit for rapid detection of Vibrio cholerae O1.

OpenAIRE

Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

1994-01-01

We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bact...

Comparative genomic analysis of two isolates of Vibrio cholerae O1 Ogawa El Tor isolated during outbreak in Mariupol in 2011.

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Kuleshov, Konstantin V; Kostikova, Anna; Pisarenko, Sergey V; Kovalev, Dmitry A; Tikhonov, Sergey N; Savelievа, Irina V; Saveliev, Vilory N; Vasilieva, Oksana V; Zinich, Liliia S; Pidchenko, Nadiia N; Kulichenko, Alexander N; Shipulin, German A

2016-10-01

Cholera is a water-borne, severe enteric infection essentially caused by toxigenic strains of Vibrio cholera O1 and O139 serogroups. An outbreak of cholera was registered during May-July 2011 in Mariupol, Ukraine, with 33 cholera cases and 25 carriers of cholera. Following this outbreak, the toxigenic strain of V. cholerae 2011EL-301 was isolated from seawater in the recreation area of Taganrog city on the territory of Russia. The aim of our study was to understand genomic features of Mariupol isolates as well as to evaluate hypothesis about possible interconnection between the outbreak of cholera in Mariupol and the single case of isolation of V. cholerae from the Sea of Azov in Russia. Mariupol isolates were phenotypically characterized and subsequently subjected to whole genome sequencing procedure. Phylogenetic analysis based on high-quality SNPs of V. cholera O1 El Tor isolates of the 7th pandemic clade from different regions showed that clinical and environmental isolates from Mariupol outbreak were attributable to a unique phylogenetic clade within wave 3 of V. cholera O1 El Tor isolates and characterized by six clade-specific SNPs. Whereas Taganrog isolate belonged to distantly related clade which allows us to reject the hypothesis of transmission the outbreak strain of V. cholerae O1 from Ukraine to Russia in 2011. Mariupol isolates shared a common ancestor with Haiti\\Nepal-4\\India clade indicating that outbreak progenitor strain most likely originated in the South Asia region and later was introduced to Ukraine. Moreover, genomic data both based on hqSNPs and similarity of virulence-associated mobile genomic elements of Mariupol isolates suggests that environmental and clinical isolates are a part of joint outbreak which confirms the role of contaminated domestic sewage, as an element of the complex chain of infection spread during cholera outbreak. In general, the genome-wide comparative analysis of both genes and genomic regions of epidemiological

Viabilidade de Vibrio cholerae O1 em diferentes tipos de águas em condições experimentais Viability of Vibrio cholerae O1 in different types of water under experimental conditions

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Joseli Maria da Rocha Nogueira

2002-10-01

Full Text Available A natureza endêmica e sazonal da cólera depende da sobrevivência de Vibrio cholerae O1 em estado viável, mas não necessariamente cultivável em nichos ambientais aquáticos durante períodos interepidêmicos, sendo de suma importância o estudo da sobrevivência deste microrganismo nesses locais. Para tal, foram coletadas, semanalmente, alíquotas de água pertencentes a duas lagoas e dois rios do Estado do Rio de Janeiro. Esses volumes foram divididos em duas porções idênticas, uma das quais foi autoclavada. Uma diluição padronizada de V. cholerae O1 Inaba e de V. cholerae O1 Ogawa, foi inoculada em três alíquotas de 100ml dessas diferentes águas e mantidas em diferentes temperaturas. A sobrevivência desses microorganismos no âmbito aquático sob esses diferentes fatores foi então analisada. Os resultados demonstraram que o V. cholerae sorogrupo O1, independente do sorotipo, é capaz de se manter em água com salinidade abaixo de 0,5‰ e em diferentes temperaturas, por períodos suficientes para sua disseminação através de "corpos d'água", demonstrando a necessidade de monitoramento constante em áreas de possível contaminação, principalmente onde a água é utilizada para o consumo, evitando assim, a disseminação da doença para as populações próximas a esses ambientes.The endemic and seasonal nature of cholera depends upon the survival of Vibrio cholerae O1 in a viable but not necessarily culturable state in ecological niches in aquatic environments during inter-epidemic periods, and investigation on the survival of this microorganism in such sites is therefore of the utmost importance. Weekly water aliquots were thus taken from 2 ponds and 2 rivers in the State of Rio de Janeiro. The samples were divided into two identical portions, one of which was autoclaved. A standardized dilution of V. cholerae O1 Inaba and of V. cholerae O1 Ogawa was inoculated in three aliquots of 100ml of these different water samples and

Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

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Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

1984-07-01

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to three plasmids. The old and new isolates of classical V. cholerae had two HindIII chromosomal digest fragments containing cholera toxin subunit A genes, whereas the eltor strains from Eastern countries had one fragment. The eltor strains from areas surrounding the Gulf of Mexico also had two subunit A gene fragments, which were smaller and easily distinguished from the classical pattern. All classical strains had 8 to 10 HindIII fragments containing the defective VcA1 prophage genome; none of the Eastern eltor strains had these genes, and the Gulf Coast eltor strains contained a different array of weakly hybridizing genes. These data suggest that the recent isolates of classical cholera in Bangladesh are closely related to the bacterial strain(s) which caused classical cholera during the sixth pandemic. These data do not support hypotheses that either the eltor or the nontoxigenic O1 strains are precursors of the new classical strains.

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

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

2016-01-01

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

Efficacy of Ciprofloxacin for Treatment of Cholera Associated with Diminished Susceptibility to Ciprofloxacin to Vibrio cholerae O1.

Science.gov (United States)

Khan, Wasif Ali; Saha, Debasish; Ahmed, Sabeena; Salam, Mohammed Abdus; Bennish, Michael Louis

2015-01-01

We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera. To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161 patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility. Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (Ptreatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains. Single-dose ciprofloxacin is not effective for treating cholera caused by V. cholerae O1 with diminished

Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

OpenAIRE

Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

1984-01-01

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to thr...

The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

Science.gov (United States)

Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

1992-01-01

Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

Characterization and genetic variation of vibrio cholerae isolated from clinical and environmental sources in Thailand

DEFF Research Database (Denmark)

Siriphap, Achiraya; Leekitcharoenphon, Pimlapas; Kaas, Rolf Sommer

2017-01-01

Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic...... and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using...... online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found...

Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.

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Danielle E Baranova

Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.

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

Science.gov (United States)

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

2016-01-01

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

Label-free electrochemical immunosensor based on cerium oxide nanowires for Vibrio cholerae O1 detection

International Nuclear Information System (INIS)

Tam, Phuong Dinh; Thang, Cao Xuan

2016-01-01

This paper developed a label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application. The CeO 2 nanowires were synthesized by hydrothermal reaction. The immobilization of Anti-V. cholerae O1 onto CeO 2 nanowire-deposited sensor was performed via an amino ester, which was created by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and sulfo-N-hydroxysuccinimide. The electrochemical responses of the immunosensor were studied by electrochemical impedance spectroscopy with [Fe (CN) 6 ] 3−/4− as redox probe. A linear response in electron transfer resistance for cell of V. cholerae O1 concentration was found in the range of 1.0 × 10 2 CFU/mL to 1.0 × 10 4 CFU/mL. The detection limit of the immunosensor was 1.0 × 10 2 CFU/mL. The immunosensor sensitivity was 56.82 Ω/CFU·mL −1 . Furthermore, the parameters affecting immunosensor response were also investigated, as follows: pH value, immunoreaction time, incubation temperature, and anti-V. cholerae O1 concentration. - Highlights: • A label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application was developed. • A linear response was found in the range of 1.0 × 10 2 CFU/mL to 1.0 × 10 4 CFU/mL. • The detection limit of the immunosensor was 1.0 × 10 2 CFU/mL. • The immunosensor sensitivity was 56.82 Ω/CFU.mL −1 .

Phase variable O antigen biosynthetic genes control expression of the major protective antigen and bacteriophage receptor in Vibrio cholerae O1.

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Kimberley D Seed

2012-09-01

Full Text Available The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage.

Genetic diversity of clinical and environmental isolates of Vibrio cholerae determined by amplified fragment length polymorphism fingerprinting.

Science.gov (United States)

Jiang, S C; Matte, M; Matte, G; Huq, A; Colwell, R R

2000-01-01

Vibrio cholerae, the causative agent of major epidemics of diarrheal disease in Bangladesh, South America, Southeastern Asia, and Africa, was isolated from clinical samples and from aquatic environments during and between epidemics over the past 20 years. To determine the evolutionary relationships and molecular diversity of these strains, in order to understand sources, origin, and epidemiology, a novel DNA fingerprinting technique, amplified fragment length polymorphism (AFLP), was employed. Two sets of restriction enzyme-primer combinations were tested for fingerprinting of V. cholerae serogroup O1, O139, and non-O1, O139 isolates. Amplification of HindIII- and TaqI-digested genomic DNA produced 30 to 50 bands for each strain. However, this combination, although capable of separating environmental isolates of O1 and non-O1 strains, was unable to distinguish between O1 and O139 clinical strains. This result confirmed that clinical O1 and O139 strains are genetically closely related. On the other hand, AFLP analyses of restriction enzyme ApaI- and TaqI-digested genomic DNA yielded 20 to 30 bands for each strain, but were able to separate O1 from O139 strains. Of the 74 strains examined with the latter combination, 26 serogroup O1 strains showed identical banding patterns and were represented by the O1 El Tor strain of the seventh pandemic. A second group, represented by O139 Bengal, included 12 strains of O139 clinical isolates, with 7 from Thailand, 3 from Bangladesh, and 2 from India. Interestingly, an O1 clinical isolate from Africa also grouped with the O139 clinical isolates. Eight clinical O1 isolates from Mexico grouped separately from the O1 El Tor of the seventh pandemic, suggesting an independent origin of these isolates. Identical fingerprints were observed between an O1 environmental isolate from a river in Chile and an O1 clinical strain from Kenya, both isolated more than 10 years apart. Both strains were distinct from the O1 seventh pandemic strain

Label-free electrochemical immunosensor based on cerium oxide nanowires for Vibrio cholerae O1 detection

Energy Technology Data Exchange (ETDEWEB)

Tam, Phuong Dinh, E-mail: phuongdinhtam@gmail.com; Thang, Cao Xuan, E-mail: thang.caoxuan@hust.edu.vn

2016-01-01

This paper developed a label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application. The CeO{sub 2} nanowires were synthesized by hydrothermal reaction. The immobilization of Anti-V. cholerae O1 onto CeO{sub 2} nanowire-deposited sensor was performed via an amino ester, which was created by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and sulfo-N-hydroxysuccinimide. The electrochemical responses of the immunosensor were studied by electrochemical impedance spectroscopy with [Fe (CN) {sub 6}] {sup 3−/4−} as redox probe. A linear response in electron transfer resistance for cell of V. cholerae O1 concentration was found in the range of 1.0 × 10{sup 2} CFU/mL to 1.0 × 10{sup 4} CFU/mL. The detection limit of the immunosensor was 1.0 × 10{sup 2} CFU/mL. The immunosensor sensitivity was 56.82 Ω/CFU·mL{sup −1}. Furthermore, the parameters affecting immunosensor response were also investigated, as follows: pH value, immunoreaction time, incubation temperature, and anti-V. cholerae O1 concentration. - Highlights: • A label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application was developed. • A linear response was found in the range of 1.0 × 10{sup 2} CFU/mL to 1.0 × 10{sup 4} CFU/mL. • The detection limit of the immunosensor was 1.0 × 10{sup 2} CFU/mL. • The immunosensor sensitivity was 56.82 Ω/CFU.mL{sup −1}.

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras

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Ivany R de Moraes

2000-02-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Cananéia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.

Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras

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Moraes Ivany R de

2000-01-01

Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Cananéia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.

Cholera Epidemiology in Nigeria: an overview | Adagbada | Pan ...

African Journals Online (AJOL)

Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium, Vibrio cholera. Choleragenic V. cholera O1 and O139 are the only causative agents of the disease. The two most distinguishing epidemiologic features of the disease are its tendency to appear in explosive ...

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

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Kazuhisa Okada

Full Text Available BACKGROUND: Vibrio cholerae O1 El Tor dominated the seventh cholera pandemic which occurred in the 1960s. For two decades, variants of V. cholerae O1 El Tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic El Tor biotype. This study aims to characterize V. cholerae O1 isolates from outbreaks in Thailand with special reference to genotypic variations over time. METHODS/FINDINGS: A total of 343 isolates of V. cholerae O1 from cholera outbreaks from 2007 to 2010 were investigated, and 99.4% were found to carry the classical cholera toxin B subunit (ctxB and El Tor rstR genes. Pulsed-field gel electrophoresis (PFGE differentiated the isolates into 10 distinct pulsotypes, clustered into two major groups, A and B, with an overall similarity of 88%. Ribotyping, multiple-locus variable-number tandem-repeat analysis (MLVA, and PCR to detect Vibrio seventh pandemic island II (VSP-II related genes of randomly selected isolates from each pulsotype corresponded to the results obtained by PFGE. Epidemiological investigations revealed that MLVA type 2 was strongly associated with a cholera outbreak in northeastern Thailand in 2007, while MLVA type 7 dominated the outbreaks of the southern Gulf areas in 2009 and MLVA type 4 dominated the outbreaks of the central Gulf areas during 2009-2010. Only MLVA type 16 isolates were found in a Thai-Myanmar border area in 2010, whereas those of MLVA types 26, 39, and 41 predominated this border area in 2008. Type 39 then disappeared 1-2 years later as MLVA type 41 became prevalent. Type 41 was also found to infect an outbreak area. CONCLUSIONS: MLVA provided a high-throughput genetic typing tool for understanding the in-depth epidemiology of cholera outbreaks. Our epidemiological surveys suggest that some clones of V. cholerae O1 with similar but distinctive genetic traits circulate in outbreak sites, while others disappear over time.

Prevalence of Vibrio cholerae O1 serogroup in Assam, India: A hospital-based study.

Science.gov (United States)

Sharma, Ajanta; Dutta, Bornali Sarmah; Rasul, Elmy Samsun; Barkataki, Dipa; Saikia, Anjanamoyee; Hazarika, Naba Kumar

2017-09-01

Although cholera remains to be an important public health problem, studies on reliable population-based estimates of laboratory confirmed cholera in endemic areas are limited worldwide. The aim of this hospital-based study was to evaluate the prevalence of Vibrio cholerae serogroup in Assam, India, during 2003-2013. Stool samples/rectal swabs were collected from acute watery diarrhoea (AWD) cases during 2003-2013 and processed by standard microbiological procedures. Antibiotic sensitivity test was done following the Clinical and Laboratory Standards Institute guidelines. Year-wise epidemiological trend of cholera was analyzed. Cholera contributed to 3.93 per cent of AWD cases. In Assam, cholera was found to be more prevalent in the rural areas (6.7%) followed by the tea gardens (5.06%), urban slum (1.9%) and urban areas (1.4%). Highest proportion of cholera (13.7%) was observed in 0-10 yr age group. Of them, 11.5 per cent belonged to 0-5 yr age group. V. cholerae O1 El Tor serotype Ogawa was the predominant isolate. Multiple drug-resistant isolates of V. cholerae O1 Ogawa were reported in the study. Emergence of resistance amongst V. cholerae towards many antibiotics is a matter of concern. Hence, continuous surveillance for diarrhoeal disorders is necessary to control the future outbreaks of cholera in this region.

Genetic diversity and population structure of Vibrio cholerae.

Science.gov (United States)

Beltrán, P; Delgado, G; Navarro, A; Trujillo, F; Selander, R K; Cravioto, A

1999-03-01

Multilocus enzyme electrophoresis (MLEE) of 397 Vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from Mexico and Guatemala, identified 279 electrophoretic types (ETs) distributed in two major divisions (I and II). Linkage disequilibrium was demonstrated in both divisions and in subdivision Ic of division I but not in subdivision Ia, which includes 76% of the ETs. Despite this evidence of relatively frequent recombination, clonal lineages may persist for periods of time measured in at least decades. In addition to the pandemic clones of serogroups O1 and O139, which form a tight cluster of four ETs in subdivision Ia, MLEE analysis identified numerous apparent clonal lineages of non-O1 strains with intercontinental distributions. A clone of serogroup O37 that demonstrated epidemic potential in the 1960s is closely related to the pandemic O1/O139 clones, but the nontoxigenic O1 Inaba El Tor reference strain is not. A strain of serogroup O22, which has been identified as the most likely donor of exogenous rfb region DNA to the O1 progenitor of the O139 clone, is distantly related to the O1/O139 clones. The close evolutionary relationships of the O1, O139, and O37 epidemic clones indicates that new cholera clones are likely to arise by the modification of a lineage that is already epidemic or is closely related to such a clone.

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

Science.gov (United States)

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

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 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. PMID:26904604

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

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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.

Viabilidade de Vibrio cholerae O1 em diferentes tipos de águas em condições experimentais

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Nogueira Joseli Maria da Rocha

2002-01-01

Full Text Available A natureza endêmica e sazonal da cólera depende da sobrevivência de Vibrio cholerae O1 em estado viável, mas não necessariamente cultivável em nichos ambientais aquáticos durante períodos interepidêmicos, sendo de suma importância o estudo da sobrevivência deste microrganismo nesses locais. Para tal, foram coletadas, semanalmente, alíquotas de água pertencentes a duas lagoas e dois rios do Estado do Rio de Janeiro. Esses volumes foram divididos em duas porções idênticas, uma das quais foi autoclavada. Uma diluição padronizada de V. cholerae O1 Inaba e de V. cholerae O1 Ogawa, foi inoculada em três alíquotas de 100ml dessas diferentes águas e mantidas em diferentes temperaturas. A sobrevivência desses microorganismos no âmbito aquático sob esses diferentes fatores foi então analisada. Os resultados demonstraram que o V. cholerae sorogrupo O1, independente do sorotipo, é capaz de se manter em água com salinidade abaixo de 0,5? e em diferentes temperaturas, por períodos suficientes para sua disseminação através de "corpos d'água", demonstrando a necessidade de monitoramento constante em áreas de possível contaminação, principalmente onde a água é utilizada para o consumo, evitando assim, a disseminação da doença para as populações próximas a esses ambientes.

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

Science.gov (United States)

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

2014-01-01

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

Genomic Epidemiology of Vibrio cholerae O1 Associated with Floods, Pakistan, 2010

Science.gov (United States)

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

2014-01-01

In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks. PMID:24378019

Diversity and distribution of cholix toxin, a novel ADP-ribosylating factor from Vibrio cholerae.

Science.gov (United States)

Purdy, Alexandra E; Balch, Deborah; Lizárraga-Partida, Marcial Leonardo; Islam, Mohammad Sirajul; Martinez-Urtaza, Jaime; Huq, Anwar; Colwell, Rita R; Bartlett, Douglas H

2010-02-01

Non-toxigenic non-O1, non-O139 Vibrio cholerae strains isolated from both environmental and clinical settings carry a suite of virulence factors aside from cholera toxin. Among V. cholerae strains isolated from coastal waters of southern California, this includes cholix toxin, an ADP-ribosylating factor that is capable of halting protein synthesis in eukaryotic cells. The prevalence of the gene encoding cholix toxin, chxA, was assessed among a collection of 155 diverse V. cholerae strains originating from both clinical and environmental settings in Bangladesh and Mexico and other countries around the globe. The chxA gene was present in 47% of 83 non-O1, non-O139 strains and 16% of 72 O1/O139 strains screened as part of this study. A total of 86 chxA gene sequences were obtained, and phylogenetic analysis revealed that they fall into two distinct clades. These two clades were also observed in the phylogenies of several housekeeping genes, suggesting that the divergence observed in chxA extends to other regions of the V. cholerae genome, and most likely has arisen from vertical descent rather than horizontal transfer. Our results clearly indicate that ChxA is a major toxin of V. cholerae with a worldwide distribution that is preferentially associated with non-pandemic strains. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Acalculous cholecystitis and septicemia caused by non-O1 Vibrio cholerae: first reported case and review of biliary infections with Vibrio cholerae.

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West, B C; Silberman, R; Otterson, W N

1998-03-01

The first case of septicemic acute acalculous cholecystitis caused by non-O1 Vibrio cholerae is described in a healthy traveler, and biliary tract infections from V. cholerae are reviewed. Immediately after a vacation in Cancun, Mexico, a 55-year-old man developed acute cholecystitis. Blood and bile cultures grew non-O1 V. cholerae. At surgery, the gallbladder was acalculous, inflamed, distended, and nearly ruptured. Pathogenetic factors may have included diarrhea prophylaxis with bismuth subsalicylate, distension of the gallbladder from illness-induced fasting, and bacterial toxins in the gallbladder. The patient received i.v. cephapirin, followed by oral cephradine for a total of 10 days, and he made a quick and complete recovery. V. cholerae should be considered in the differential diagnosis of persons from endemic areas who present with cholecystitis or acute jaundice.

Survival of Vibrio cholerae O1 on fomites

DEFF Research Database (Denmark)

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

2016-01-01

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...

Vibrio cholerae No O1 en muestras de aguas no cloradas consumidas por pobladores de las localidades de Santa y Coishco (Ancash, 2003 - 2004

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Ana García P

2006-07-01

Full Text Available Objetivo: Identificar la presencia de Vibrio cholerae en muestras de agua no cloradas para consumo humano en las localidades de Santa y Coishco. Materiales y métodos: Entre julio de 2003 a junio de 2004 se tomaron muestras de agua, en forma semanal, provenientes de siete pozos con bomba manuable y de seis pozos con reservorio. A cada muestra de agua se le midió in situ el cloro residual mediante un comparador de cloro Hatch, método colorimétrico, usando para ello las pastillas DPD 1. En las muestras con cloro <0,05mg/L se realizó el cultivo según los manuales de procedimientos del Instituto Nacional de Salud (INS, Lima. Las cepas aisladas se enviaron al INS para confirmación diagnóstica y pruebas serológicas. Resultados: Se incluyeron 308 muestras de agua para consumo humano en ambos distritos (201 de pozos con bomba manuable y 107 con reservorio. Se realizó el aislamiento en 70(22,7% muestras: Aeromonas caviae 34(11,0%, Aeromonas hidrophyla 17(5,5% y Vibrio cholerae No O1 19(6,2%, no se encontró V. cholerae del serotipo O139. El Vibrio cholerae No O1 se aisló en 11(5,5% muestras de pozos con bomba manuable y en 8(7,4% pozos con reservorio, respectivamente. Conclusión: El agua de consumo humano proveniente de pozos tubulares representa un reservorio potencial para bacterias como Aeromonas y Vibrio cholerae, resaltando la necesidad de realizar la desinfección correspondiente de ésta antes de su consumo.

Tiempo de excreción de Vibrio cholerae O1 en pacientes con tratamiento

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Elizabeth Castañeda

1992-12-01

Full Text Available El tiempo de excreción del Vibrio cholerae O1 en pacientes con cólera está influenciado por el tratamiento antimicrobiano. Se determinó en un grupo de pacientes con diagnóstico bacteriológico de cólera, que empezaron a recibir tratamiento con antibióticos una vez establecido el diagnóstico clínico, el tiempo de excreción del V. cholerae O1 empleando muestras de materia fecal obtenidas dentro de los cinco días siguientes al diagnóstico clínico inicial. En las 32 muestras obtenidas en ese período de cinco días el porcentaje de negativos fue del 81,2% (26/ 32; en 21 muestras obtenidas 24 horas después de haberse establecido el diagnóstico, se observó negativización en el 81% (17/21. Con nuestros datos podemos confirmar, al compararlos con los datos de la literatura en pacientes no tratados, que el tratamiento acorta el periodo de excreción del V. cholerae O1.

Vibrio cholerae O1 epidemic variants in Angola: a retrospective study between 1992 and 2006.

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Romy eValia

2013-11-01

Full Text Available Cholera is still a major public health concern in many African countries. In Angola, after a decade of absence, cholera reemerged in 1987, spreading throughout the country until 1996, with outbreaks recurring in a seasonal pattern. In 2006 Angola was hit by one of the most severe outbreaks of the last decade, with ca. 240,000 cases reported.We analyzed 21 clinical strains isolated between 1992 and 2006 from several provinces throughout the country: Benguela, Bengo, Luanda, Cuando Cubango and Cabinda. We used two multiplex PCR assays to investigate discriminatory mobile genetic elements (ICEs, VSP-II, GI12, GI14, GI15, K and TLC phages and we compared the profiles obtained with those of different reference V. cholerae O1 variants (prototypical, altered and hybrid, responsible for the ongoing 7th pandemic. We also tested the strains for the presence of specific VSP-II variants and for the presence of a genomic island (WASA-1, correlated with the transmission of seventh pandemic cholera from Africa to South America. Based on the presence/absence of the analyzed genetic elements, five novel profiles were detected in the epidemic strains circulating in the 1990s. The most frequent profiles, F and G, were characterized by the absence of ICEs and the three GIs tested, and the presence of genomic island WASA-1 and the WASA variant of the VSP-II island. Our results identified unexpected variability within the 1990s epidemic, showing different rearrangements in a dynamic part of the genome not present in the prototypical V. cholerae O1 N16961. Moreover the 2006 strains differed from the current pandemic V. cholerae O1 strain. Taken together, our results highlight the role of horizontal gene transfer in diversifying the genetic background of V. cholerae within a single epidemic.

Vibrio cholerae O1 epidemic variants in Angola: a retrospective study between 1992 and 2006.

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Valia, Romy; Taviani, Elisa; Spagnoletti, Matteo; Ceccarelli, Daniela; Cappuccinelli, Piero; Colombo, Mauro M

2013-01-01

Cholera is still a major public health concern in many African countries. In Angola, after a decade of absence, cholera reemerged in 1987, spreading throughout the country until 1996, with outbreaks recurring in a seasonal pattern. In 2006 Angola was hit by one of the most severe outbreaks of the last decade, with ca. 240,000 cases reported. We analyzed 21 clinical strains isolated between 1992 and 2006 from several provinces throughout the country: Benguela, Bengo, Luanda, Cuando Cubango, and Cabinda. We used two multiplex PCR assays to investigate discriminatory mobile genetic elements (MGE) [Integrative Conjugative Elements (ICEs), VSP-II, GI12, GI14, GI15, K, and TLC phages] and we compared the profiles obtained with those of different reference V. cholerae O1 variants (prototypical, altered, and hybrid), responsible for the ongoing 7th pandemic. We also tested the strains for the presence of specific VSP-II variants and for the presence of a genomic island (GI) (WASA-1), correlated with the transmission of seventh pandemic cholera from Africa to South America. Based on the presence/absence of the analyzed genetic elements, five novel profiles were detected in the epidemic strains circulating in the 1990s. The most frequent profiles, F and G, were characterized by the absence of ICEs and the three GIs tested, and the presence of GI WASA-1 and the WASA variant of the VSP-II island. Our results identified unexpected variability within the 1990s epidemic, showing different rearrangements in a dynamic part of the genome not present in the prototypical V. cholerae O1 N16961. Moreover the 2006 strains differed from the current pandemic V. cholerae O1 strain. Taken together, our results highlight the role of horizontal gene transfer (HGT) in diversifying the genetic background of V. cholerae within a single epidemic.

gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples.

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Luigi Vezzulli

Full Text Available The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA is a chitin-binding protein involved in V. cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V. cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V. cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR samples. Overall, the method is sensitive (50 gene copies, highly specific for V. cholerae and failed to amplify strains of the closely-related species Vibrio mimicus. The sensitivity of the assay applied to environmental and stool samples spiked with V. cholerae ATCC 39315 was comparable to that of pure cultures and was of 102 genomic units/l for drinking and seawater samples, 101 genomic units/g for sediment and 102 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V. cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V. cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies.

Molecular analyses of Vibrio cholerae O1 clinical strains, including new nontoxigenic variants isolated in Mexico during the Cholera epidemic years between 1991 and 2000.

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Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

2009-05-01

We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1.

El Niño, Rainfall, and the Shifting Geography of Cholera in Africa

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Moore, S.; Azman, A. S.; Zaitchik, B. F.; McKay, H.; Lessler, J.

2017-12-01

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between El Niño patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa where many cholera cases and deaths are reported. To understand how ENSO affects the geographic distribution of cholera incidence in Africa, we used a hierarchical Bayesian approach to integrate over 17,000 annual observations of cholera incidence from 2000-2014 in over 3,000 unique locations of varying spatial extent, ranging from entire countries to neighborhoods. The resulting maps reflect modeled cholera incidence at a fine spatial resolution using reported counts of cholera cases, key explanatory variables, and a spatially-dependent covariance term. We then examined the potential mechanistic association between ENSO-related changes in cholera incidence and several environmental variables including rainfall. El Niño profoundly changed the annual geographic distribution of cholera in Africa from 2000-2014, shifting the burden to continental East Africa, where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall suggesting a complex relationship between rainfall and cholera incidence. Here we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño and non-El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with El Niño forecasting could be used to notify countries in Africa when they are likely to see

Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000▿

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Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

2009-01-01

We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1. PMID:19213700

Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

DEFF Research Database (Denmark)

Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

2016-01-01

gene (tcpA) and the haemolysin gene (hlyA). RESULTS: The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while......BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...

The aquatic environment as a reservoir of Vibrio cholerae O1 in hydrographic basins of the state of Pernambuco, Brazil.

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Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

2013-01-01

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.

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

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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.

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

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Seon Young Choi

2016-03-01

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

Comparative genomic characterization of a Thailand-Myanmar isolate, MS6, of Vibrio cholerae O1 El Tor, which is phylogenetically related to a "US Gulf Coast" clone.

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Okada, Kazuhisa; Na-Ubol, Mathukorn; Natakuathung, Wirongrong; Roobthaisong, Amonrattana; Maruyama, Fumito; Nakagawa, Ichiro; Chantaroj, Siriporn; Hamada, Shigeyuki

2014-01-01

The cholera outbreaks in Thailand during 2007-2010 were exclusively caused by the Vibrio cholerae O1 El Tor variant carrying the cholera toxin gene of the classical biotype. We previously isolated a V. cholerae O1 El Tor strain from a patient with diarrhea and designated it MS6. Multilocus sequence-typing analysis revealed that MS6 is most closely related to the U. S. Gulf Coast clone with the exception of two novel housekeeping genes. The nucleotide sequence of the genome of MS6 was determined and compared with those of 26 V. cholerae strains isolated from clinical and environmental sources worldwide. We show here that the MS6 isolate is distantly related to the ongoing seventh pandemic V. cholerae O1 El Tor strains. These strains differ with respect to polymorphisms in housekeeping genes, seventh pandemic group-specific markers, CTX phages, two genes encoding predicted transmembrane proteins, the presence of metY (MS6_A0927) or hchA/luxR in a highly conserved region of the V. cholerae O1 serogroup, and a superintegron (SI). We found that V. cholerae species carry either hchA/luxR or metY and that the V. cholerae O1 clade commonly possesses hchA/luxR, except for MS6 and U. S. Gulf Coast strains. These findings illuminate the evolutionary relationships among V. cholerae O1 strains. Moreover, the MS6 SI carries a quinolone-resistance gene cassette, which was closely related with those present in plasmid-borne integrons of other gram-negative bacteria. Phylogenetic analysis reveals that MS6 is most closely related to a U. S. Gulf Coast clone, indicating their divergence before that of the El Tor biotype strains from a common V. cholerae O1 ancestor. We propose that MS6 serves as an environmental aquatic reservoir of V. cholerae O1.

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

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

2003-06-01

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

Anethole inhibits growth of recently emerged multidrug resistant toxigenic Vibrio cholerae O1 El Tor variant strains in vitro.

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Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Hinenoya, Atsushi; Yamasaki, Shinji

2015-05-01

To search natural compounds having inhibitory effect on bacterial growth is important, particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens. Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent of diarrheal disease cholera, is becoming a great concern. As an approach of searching new antimicrobial agents, here, we show that anethole, a well-studied natural component of sweet fennel and star anise seeds, could potentially inhibit the growth of MDR O1 El Tor biotype, the ongoing 7th cholera pandemic variant strains of toxigenic V. cholerae. The minimum inhibitory concentration (MIC) of anethole against diverse O1 El Tor biotype strains is evaluated as 200 µg/ml. Moreover, the effect of anethole is bactericidal and exerts rapid-killing action on V. cholerae cells. This study is the first report which demonstrates that anethole, purified from natural compound, is a potent inhibitor of growth of toxigenic V. cholerae. Our data suggest that anethole could be a potential antimicrobial drug candidate, particularly against MDR V. cholerae mediated infections.

Molecular characterisation of Vibrio cholerae O1 strains carrying an SXT/R391-like element from cholera outbreaks in Kenya: 1994-2007

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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

Recommendations of the Advisory Committee on Immunization Practices for Use of Cholera Vaccine.

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Wong, Karen K; Burdette, Erin; Mahon, Barbara E; Mintz, Eric D; Ryan, Edward T; Reingold, Arthur L

2017-05-12

Cholera, caused by infection with toxigenic Vibrio cholerae bacteria of serogroup O1 (>99% of global cases) or O139, is characterized by watery diarrhea that can be severe and rapidly fatal without prompt rehydration. Cholera is endemic in approximately 60 countries and causes epidemics as well. Globally, cholera results in an estimated 2.9 million cases of disease and 95,000 deaths annually (1). Cholera is rare in the United States, and most U.S. cases occur among travelers to countries where cholera is endemic or epidemic. Forty-two U.S. cases were reported in 2011 after a cholera epidemic began in Haiti (2); however, <25 cases per year have been reported in the United States since 2012.

Vibrio cholerae Colonization of Soft-Shelled Turtles.

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Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

2017-07-15

Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

Ecología de Vibrio cholerae en relación al Fitoplancton y variables fisicoquímicas en ríos de Tucumán (Argentina Ecology of Vibrio cholerae in relation to phytoplankton and physico-chemical variables in rivers of Tucumán (Argentina

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V. Mirande

Full Text Available Vibrio cholerae muestra gran diversidad serológica en base a su antígeno somático O, conociéndose al menos 200 serogrupos. De éstos, solamente O1 y O139 son causantes de epidemias o pandemias. En Latinoamérica el serogrupo O1 reapareció en 1991, tras cien años de no presentar brotes en el continente. Esta bacteria sobrevive y se multiplica asociada al plancton, independientemente de la aparición de infecciones humanas. Desde la década del noventa, en Tucumán, se detectaron casos esporádicos de diarrea por Vibrio cholerae no-O1. El objetivo del presente trabajo fue estudiar la posible relación entre la presencia de especímenes de fitoplancton, variables fisicoquímicas y aislamientos de Vibrio cholerae en ríos de Tucumán. Se realizaron 18 campañas en los ríos Lules y Salí entre 2003-2005. Se estudiaron las variables fisicoquímicas del agua (pH, temperatura, conductividad y oxígeno disuelto, el fitoplancton (riqueza y frecuencia relativa y las cepas aisladas de V. cholerae. Los resultados evidenciaron diferencias en la calidad del agua, observándose períodos de anoxia en el río Salí. Las diatomeas sobresalieron en la mayoría de los meses y generalmente estuvieron en porcentajes superiores al 85 %. Sólo se aisló Vibrio cholerae no-O1, no-O139, detectándose más frecuentemente en los meses cálidos, con pH alcalino, aún con baja concentración de oxígeno.Vibrio cholerae shows a great serologic diversity in relation to his O somatic antigen and we know at least 200 serogroups. About these, only O1 and O139 are responsible of epidemics and pandemics. The serogroup O1 reemerged in Latin America in 1991 after being absent from the continent for nearly a century. This bacterium survives and grows up associated to plankton, independently of appearance of human infections. From 90 th decade, there were sporadic cases of diarrhea because of Vibrio cholerae O1 in Tucumán. The aims of this paper were to study the possible

Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

Science.gov (United States)

Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

2016-06-01

No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000

OpenAIRE

Lizárraga-Partida, Leonardo; Quilici, Marie-Laure

2009-01-01

International audience; We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI r...

Development of simple and rapid PCR-fingerprinting methods for Vibrio cholerae on the basis of genetic diversity of the superintegron.

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Chowdhury, N; Asakura, M; Neogi, S B; Hinenoya, A; Haldar, S; Ramamurthy, T; Sarkar, B L; Faruque, S M; Yamasaki, S

2010-07-01

To develop simple and rapid PCR-fingerprinting methods for Vibrio cholerae O1 (El Tor and classical biotypes) and O139 serogroup strains which cause major cholera epidemics, on the basis of the diversity of superintegron (SI) carried by these strains. PCR-restriction fragment length polymorphism (PCR-RFLP) assay was developed targeting region between integrase gene in the SI and its nearby ORF, followed by BglI digestion. Besides, a V. cholerae repeat-amplified fragment length polymorphism (VCR-AFLP) assay was also developed. In the PCR-RFLP, 94 El Tor, 29 classical and 54 O139 strains produced nine, three and six different DNA fingerprints, respectively. On the other hand, VCR-AFLP distinguished these El Tor, classical and O139 strains into five, nine and two DNA fingerprints, respectively. Combining both assays the El Tor, classical and O139 strains could be differentiated into 11, 10 and seven different types, respectively. In a comparative study, pulsed-field gel electrophoresis (PFGE) showed similar differentiation for El Tor (11 types), but lower discrimination for O139 (two types) and classical strains (five types). The PCR assays based on SI diversity can be used as a useful typing tool for epidemiological studies of V. cholerae. This newly developed method is more discriminatory, simple, rapid and cost-effective in comparison with PFGE, and thus can be widely applicable. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Isolation of Vibrio cholerae serotype O1 from the eastern oyster, Crassostrea virginica.

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Hood, M A; Ness, G E; Rodrick, G E

1981-01-01

Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination. PMID:7235700

Investigation of water sources as reservoirs of Vibrio cholerae in Bepanda, Douala and determination of physico-chemical factors maintaining its endemicity

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Akoachere J.-F.K. Tatah

2012-06-01

Full Text Available Cholera remains a significant cause of mortality in developing countries. Outbreaks of the disease are associated with poverty, lack of potable water and poor sanitation. The survival and persistence of Vibrio cholerae in water has been shown to depend on physico-chemical factors. We studied water sources in Bepanda, an overcrowded neighbourhood in Douala, Cameroon, with limited access to portable water and very poor sanitary conditions as reservoirs of V. cholerae. We analysed 318 samples from various sources (well, tap, stream from February to July 2009 using standard microbiological techniques and characterised isolates serologically using the polyvalent O1/O139 antisera. Susceptibility to antibiotics previously used for cholera treatment in Douala was studied using the disk diffusion method. Physico-chemical factors (temperature, pH and salinity that could maintain the endemicity of the organism were analysed using standard methods. Eighty-seven (27.4% samples were contaminated, with high isolation rates being obtained from streams (52.4% and wells (29.8%. The number of isolates was significantly higher (P < 0.05 in the rainy season (35.5%. We detected 23 (24% O1 serogroup isolates in streams and wells, whilst 64 (66.6% were non-O1/non-O139. Temperature and salinity correlated positively with the occurrence of the organisms. All isolates were susceptible to fluoroquinolones but high resistance rates to trimethoprim or sulfamethozaxole and tetracycline were observed. Vibrio cholerae is endemic in Bepanda with O1 and non-O1/non-O139 serogroups co-existing in the streams and wells hence the possibility of future outbreaks of cholera if sanitation and drinking water quality are not improved. Temperature and salinity are amongst the factors maintaining the endemicity of the organism.

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

DEFF Research Database (Denmark)

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

water fish may serve as a transmission vehicle of potential emerging epidemic causing strains. For this, we studied 9 toxigenic V. cholerae strains isolated from Hilsha fish including 6 V. cholerae O1 and 3 non O1/O139 serogroups for virulence associated genotype and their pathogenic potential on animal......Exposure to contaminated fish may upsurge the virulent strains of Vibrio cholerae, the deadly human pathogen in the households of rural and urban Bangladesh. Since V. cholerae spreading was reported from the Bay of Bengal, this study hypothesized that Hilsha (Tenualosa ilisha), a marine and fresh...

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

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

2016-03-15

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. Sequencing of genomes of V. cholerae is critical if genetic changes occurring over time in the circulating population of an area of endemicity are to be understood. Although cholera outbreaks occurred rarely

El Niño, Climate, and Cholera Associations in Piura, Peru, 1991-2001: A Wavelet Analysis.

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Ramírez, Iván J; Grady, Sue C

2016-03-01

In Peru, it was hypothesized that epidemic cholera in 1991 was linked to El Niño, the warm phase of El Niño-Southern Oscillation. While previous studies demonstrated an association in 1997-1998, using cross-sectional data, they did not assess the consistency of this relationship across the decade. Thus, how strong or variable an El Niño-cholera relationship was in Peru or whether El Niño triggered epidemic cholera early in the decade remains unknown. In this study, wavelet and mediation analyses were used to characterize temporal patterns among El Niño, local climate variables (rainfall, river discharge, and air temperature), and cholera incidence in Piura, Peru from 1991 to 2001 and to estimate the mediating effects of local climate on El Niño-cholera relationships. The study hypothesis is that El Niño-related connections with cholera in Piura were transient and interconnected via local climate pathways. Overall, our findings provide evidence that a strong El Niño-cholera link, mediated by local hydrology, existed in the latter part of the 1990s but found no evidence of an El Niño association in the earlier part of the decade, suggesting that El Niño may not have precipitated cholera emergence in Piura. Further examinations of cholera epicenters in Peru are recommended to support these results in Piura. For public health planning, the results may improve existing efforts that utilize El Niño monitoring for preparedness during future climate-related extremes in the region.

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

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

2009-03-01

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

Microcrustáceos y Vibrio cholerae O1 viable no cultivable (VNC: resultados en la Cuenca del Río Salí, Tucumán, Argentina Microcrustaceans and viable but nonculturable (VNC Vibrio cholerae O1: results in the Salí River basin, Tucumán, Argentina

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Cecilia Locascio de Mitrovich

2010-01-01

Full Text Available Vibrio cholerae reside habitualmente en aguas marinas y continentales. Según las condiciones ambientales y los recursos le sean “favorables” o “desfavorables”, se generan estados viables cultivables (VC o viables no cultivables (VNC respectivamente y, bajo esta última forma sobrevive. Para abordar la problemática del cólera en la Cuenca del Río Salí (Tucumán, Argentina, se realizaron muestreos durante los años 2003-2005 donde se consideraron aspectos fisicos, químicos, biológicos y sanitarios. Para evaluar los probables reservorios del patógeno, se analizó el zooplancton del Río Salí (Canal Norte y Banda Río Salí y Río Lules. La mayor representatividad taxonómica la registraron los copépodos, especialmente Eucyclops neumani (Pesta, 1927, junto a Acanthocyclops robustus (Sars, 1863, Metacyclops sp., Paracyclops chiltoni y Notodiaptomus incompositus (Brian, 1925, además de algunos rotíferos y cladóceros como (Lecane sp., y (Brachionus sp., Moina sp. y Leydigia sp.. La frecuencia de ocurrencia fue baja y no superó el 25%. El Canal Norte fue ambiente más propicio por la riqueza específica, abundancia y constancia de la comunidad. Las variables fisicas y químicas asociadas al zooplancton coincidirían con los valores que por nuestros registros y los antecedentes, se conocen para el desarrollo del patógeno. En el período estival hubo coincidencia entre la presencia de la forma VNC de V. cholerae O1 (inmunofluorescencia con anticuerpos anti O1 y el desarrollo del zooplancton. Se observaron formas VNC sobre apéndices o estructuras de copépodos ciclopoideos y cladóceros quidóridos, reflejando probablemente afinidad con sustratos quitinosos.Vibrio cholerae habitually lives in marine and continental waters. According to "favourable" or "unfavourable" resources and environmental conditions, viable (VC or viable non-culturable (VNC states will be generated, surviving only the latter form. To address the problem of

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

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Bazargan SA

1996-07-01

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

Comparative genome analysis of VSP-II and SNPs reveals heterogenic variation in contemporary strains of Vibrio cholerae O1 isolated from cholera patients in Kolkata, India.

Science.gov (United States)

Imamura, Daisuke; Morita, Masatomo; Sekizuka, Tsuyoshi; Mizuno, Tamaki; Takemura, Taichiro; Yamashiro, Tetsu; Chowdhury, Goutam; Pazhani, Gururaja P; Mukhopadhyay, Asish K; Ramamurthy, Thandavarayan; Miyoshi, Shin-Ichi; Kuroda, Makoto; Shinoda, Sumio; Ohnishi, Makoto

2017-02-01

Cholera is an acute diarrheal disease and a major public health problem in many developing countries in Asia, Africa, and Latin America. Since the Bay of Bengal is considered the epicenter for the seventh cholera pandemic, it is important to understand the genetic dynamism of Vibrio cholerae from Kolkata, as a representative of the Bengal region. We analyzed whole genome sequence data of V. cholerae O1 isolated from cholera patients in Kolkata, India, from 2007 to 2014 and identified the heterogeneous genomic region in these strains. In addition, we carried out a phylogenetic analysis based on the whole genome single nucleotide polymorphisms to determine the genetic lineage of strains in Kolkata. This analysis revealed the heterogeneity of the Vibrio seventh pandemic island (VSP)-II in Kolkata strains. The ctxB genotype was also heterogeneous and was highly related to VSP-II types. In addition, phylogenetic analysis revealed the shifts in predominant strains in Kolkata. Two distinct lineages, 1 and 2, were found between 2007 and 2010. However, the proportion changed markedly in 2010 and lineage 2 strains were predominant thereafter. Lineage 2 can be divided into four sublineages, I, II, III and IV. The results of this study indicate that lineages 1 and 2-I were concurrently prevalent between 2007 and 2009, and lineage 2-III observed in 2010, followed by the predominance of lineage 2-IV in 2011 and continued until 2014. Our findings demonstrate that the epidemic of cholera in Kolkata was caused by several distinct strains that have been constantly changing within the genetic lineages of V. cholerae O1 in recent years.

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

Science.gov (United States)

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

2014-01-01

Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Household Transmission of Vibrio cholerae in Bangladesh.

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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

Laboratory evaluation of immunochromatographic rapid diagnostic tests for cholera in Haiti.

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Wilfredo R Matias

Full Text Available Rapid diagnostic tests (RDT for cholera are promising tools for detecting cholera in areas with limited laboratory infrastructure. However, evidence on the characteristics of the many available RDTs is scarce, and their use has been limited by suboptimal performance. We evaluated the performance characteristics of three cholera RDTs from Span Diagnostics, Artron Laboratories, and Standard Diagnostics in a regional laboratory in Haiti.We retrospectively reviewed records from May 2014 to October 2015 of a laboratory-based surveillance program for Vibrio cholerae at Hôpital Saint-Nicolas in Saint-Marc, Haiti. We compared the results of 511 Crystal VC, 129 Artron and 451 SD Bioline RDTs to bacterial culture as the gold standard. Of 905 cultures, 477 (52.7% were positive for V. cholerae O1, of which 27.7% were serotype Inaba. No cultures grew V. cholerae O139. Sensitivity and specificity of Crystal VC were 98.6% (95%CI: 96.5%-99.6% and 71.1% (95%CI: 64.7%-76.9%, respectively. Artron demonstrated a sensitivity of 98.6% (95%CI: 92.7%-100% and specificity of 69.1% (95%CI: 55.2%-80.9%. SD Bioline demonstrated a sensitivity of 81.1% (95%CI: 75.6%-85.8% and specificity of 92.8% (95%CI: 88.4%-95.9%. Crystal VC and Artron frequently showed false positive O139 bands, whereas none were seen with SD Bioline.There is significant variation in the performance of different cholera diagnostic RDTs. Artron and Crystal VC RDTs have high sensitivity and low specificity, while SD Bioline RDT has low to moderate sensitivity and high specificity when performed by laboratory technicians in Haiti. Study limitations included its retrospective design. The suboptimal characteristics of these tests limit their use as clinical point-of-care tests; however, they may be useful in outbreak response, surveillance, and research in resource-limited settings.

Phenotypic and genetic characterization of Vibrio cholerae O1 clinical isolates collected through national antimicrobial resistance surveillance network in Nepal.

Science.gov (United States)

Shakya, Geeta; Kim, Dong Wook; Clemens, John D; Malla, Sarala; Upadhyaya, Bishnu Prasad; Dumre, Shyam Prakash; Shrestha, Sirjana Devi; Adhikari, Shailaja; Sharma, Supriya; Rijal, Nisha; Shrestha, Sanjaya K; Mason, Carl; Kansakar, Palpasa

2012-08-01

Cholera occurs in sporadic cases and outbreaks in Nepal each year. Vibrio cholerae O1 (n = 522) isolated during 2007-2010 from diarrheal patients at 10 different hospital laboratories in Nepal were characterized. Biochemical and serologic identifications showed that all the isolates belonged to serogroup O1, El Tor biotype. Except 72 isolates of Inaba serotype isolated in the year 2007, all the remaining isolates were of Ogawa serotype. All isolates were resistant to nalidixic acid and furazolidone. Resistance to tetracycline, ciprofloxacin, erythromycin and co-trimoxazole were 21, 4, 16 and 90 % respectively. Seventy-seven of these isolates were selected for further characterization for ctxB gene and MLVA typing. Two different variants of classical type cholera toxin were observed. Ogawa strains from 2007 and 2010-Western Nepal outbreak harbored CTX-3 type cholera toxin, whereas Inaba serotypes in 2007 and the remaining Ogawa serotypes in 2008-2010 harbored CTX 3b-type toxin. MLVA analysis showed circulation of four different groups of altered V. cholerae O1 El Tor strains. Two different profiles were seen among 2007 Inaba (9, 3, 6, x, x) and Ogawa (10, 7, 6, x, x) isolates. The MLVA profile of 2008 and 2009 Ogawa isolates were similar to those of Inaba strains of 2007. Isolates from 2010 also showed three different MLVA profiles; profile 9, 3, 6, x, x in 3 isolates, 11, 7, 6, x, x among 2010 Western Nepal outbreak strains and profile 8, 3, 6, x, x among isolates from Butwal and Kathmandu.

[Phenotypic diversity of toxigenic Vibrio cholerae O1 El Tor strains identified in China].

Science.gov (United States)

Zhao, Xuan; Zhang, Li; Li, Jie; Kan, Biao; Liang, Weili

2014-05-01

To understand the phenotypic diversity of toxigenic Vibrio cholerae O1 El Tor strains isolated from different provinces in China during the last 50 years. Traditional biotyping testings including susceptibility to polymyxin B, sensitivity to group IV phage, Voges-Proskauer test and haemolysis of sheep erythrocytes were conducted. Data from Biotype-specific phenotype analysis revealed that only 133 isolates carried the typical El Tor phenotypes while the other 251 isolates displayed atypical El Tor phenotypes. Combined with ctxB, rstR genotypes and phenotypic characteristics, 64 isolates were identified as typical El Tor biotype, 21 were El Tor variants that showing the typical El Tor biotype-specific phenotype but with ctxB(class). 280 isolates were defined as the hybrid groups with traits of both classical and El Tor biotypes that could be further classified into 45 groups, based on the combination of genotypes of ctxB, rstR and phenotypic characteristics. Toxigenic Vibrio cholerae O1 El Tor strains that isolated from different provinces in China displayed high phenotypic diversity. The traditional biotype traits could not be used to correctly distinguish the two different biotypes.

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

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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

Molecular insights into the evolutionary pathway of Vibrio cholerae O1 atypical El Tor variants.

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Kim, Eun Jin; Lee, Dokyung; Moon, Se Hoon; Lee, Chan Hee; Kim, Sang Jun; Lee, Jae Hyun; Kim, Jae Ouk; Song, Manki; Das, Bhabatosh; Clemens, John D; Pape, Jean William; Nair, G Balakrish; Kim, Dong Wook

2014-09-01

Pandemic V. cholerae strains in the O1 serogroup have 2 biotypes: classical and El Tor. The classical biotype strains of the sixth pandemic, which encode the classical type cholera toxin (CT), have been replaced by El Tor biotype strains of the seventh pandemic. The prototype El Tor strains that produce biotype-specific cholera toxin are being replaced by atypical El Tor variants that harbor classical cholera toxin. Atypical El Tor strains are categorized into 2 groups, Wave 2 and Wave 3 strains, based on genomic variations and the CTX phage that they harbor. Whole-genome analysis of V. cholerae strains in the seventh cholera pandemic has demonstrated gradual changes in the genome of prototype and atypical El Tor strains, indicating that atypical strains arose from the prototype strains by replacing the CTX phages. We examined the molecular mechanisms that effected the emergence of El Tor strains with classical cholera toxin-carrying phage. We isolated an intermediary V. cholerae strain that carried two different CTX phages that encode El Tor and classical cholera toxin, respectively. We show here that the intermediary strain can be converted into various Wave 2 strains and can act as the source of the novel mosaic CTX phages. These results imply that the Wave 2 and Wave 3 strains may have been generated from such intermediary strains in nature. Prototype El Tor strains can become Wave 3 strains by excision of CTX-1 and re-equipping with the new CTX phages. Our data suggest that inter-chromosomal recombination between 2 types of CTX phages is possible when a host bacterial cell is infected by multiple CTX phages. Our study also provides molecular insights into population changes in V. cholerae in the absence of significant changes to the genome but by replacement of the CTX prophage that they harbor.

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

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Pappu Kumar Gupta

2016-06-01

Full Text Available Abstract 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 from watery diarrhea during July to December 2012 were obtained from outbreak areas from all over Nepal. Alkaline peptone water and thiosulphate citrate bile salt sucrose agar (TCBS were used to isolate the Vibrio cholerae. The isolates were identified with the help of colony morphology, Gram’s staining, conventional biochemical testing, serotyping and biotyping. Antimicrobial susceptibility testing was performed by determining the minimum inhibitory concentration (MIC by agar dilution method. Results Vibrio cholerae was isolated from 26.72 % of total samples. All isolated Vibrio cholerae were confirmed to be Vibrio cholerae serogoup O1 biotype El Tor and serotype Ogawa. All isolates were resistant to ampicillin and cotrimoxazole. Twenty nine isolates were resistant toward two different classes of antibiotics, one strain was resistant to three different classes of antibiotics and one strain was resistant to four different classes of antibiotics. According to the definition of the multidrug resistant bacteria; 6.45 % of the strains of Vibrio cholerae were found to be multidrug resistant. Conclusions Cholera due to multidrug resistant Vibrio cholerae is also possible in Nepal. According to the antimicrobial susceptibility pattern of Vibrio cholerae in our study we recommend to use any antibiotics among tetracycline, doxycycline, levofloxacin, azithromycin, chloramphenicol and ciprofloxacin for preliminary treatment of cholera in Nepal.

Transcriptional and post-transcriptional regulation of pst2 operon expression in Vibrio cholerae O1.

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da C Leite, Daniel M; Barbosa, Livia C; Mantuano, Nathalia; Goulart, Carolina L; Veríssimo da Costa, Giovani C; Bisch, Paulo M; von Krüger, Wanda M A

2017-07-01

One of the most abundant proteins in V. cholerae O1 cells grown under inorganic phosphate (Pi) limitation is PstS, the periplasmic Pi-binding component of the high-affinity Pi transport system Pst2 (PstSCAB), encoded in pst2 operon (pstS-pstC2-pstA2-pstB2). Besides its role in Pi uptake, Pst2 has been also associated with V. cholerae virulence. However, the mechanisms regulating pst2 expression and the non-stoichiometric production of the Pst2 components under Pi-limitation are unknown. A computational-experimental approach was used to elucidate the regulatory mechanisms behind pst2 expression in V. cholerae O1. Bioinformatics analysis of pst2 operon nucleotide sequence revealed start codons for pstS and pstC genes distinct from those originally annotated, a regulatory region upstream pstS containing potential PhoB-binding sites and a pstS-pstC intergenic region longer than predicted. Analysis of nucleotide sequence between pstS-pstC revealed inverted repeats able to form stem-loop structures followed by a potential RNAse E-cleavage site. Another putative RNase E recognition site was identified within the pstA-pstB intergenic sequence. In silico predictions of pst2 operon expression regulation were subsequently tested using cells grown under Pi limitation by promoter-lacZ fusion, gel electrophoresis mobility shift assay and quantitative RT-PCR. The experimental and in silico results matched very well and led us to propose a pst2 promoter sequence upstream of pstS gene distinct from the previously annotated. Furthermore, V. cholerae O1 pst2 operon transcription is PhoB-dependent and generates a polycistronic mRNA molecule that is rapidly processed into minor transcripts of distinct stabilities. The most stable was the pstS-encoding mRNA, which correlates with PstS higher levels relative to other Pst2 components in Pi-starved cells. The relatively higher stability of pstS and pstB transcripts seems to rely on the secondary structures at their 3' untranslated regions

Occurrence of Vibrio cholerae in fish and water from a reservoir and a neighboring channel in Ouagadougou, Burkina Faso.

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Traoré, Oumar; Martikainen, Outi; Siitonen, Anja; Traoré, Alfred S; Barro, Nicolas; Haukka, Kaisa

2014-10-15

Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. In this study, we surveyed the occurrence of V. cholerae in fish harvested from a reservoir that receives discharges from the population in Ouagadougou through several channels. A total of 238 fish and 80 water samples were analyzed for the presence of V. cholerae. Altogether, 13 V. cholerae strains were isolated. They were all identified as non-O1/non-O139 V. cholerae without the ctxA gene. The strains were mostly susceptible to the antimicrobials tested. Although no strains of epidemic V. cholerae serotypes were encountered, it is important to monitor the microbiological quality of this extensively used water resource and its fish.

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.

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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.

Vibrio cholerae interactions with Mytilus galloprovincialis hemocytes mediated by serum components.

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Laura eCanesi

2013-12-01

Full Text Available Edible bivalves (e.g., mussels, oysters can accumulate large amount of bacteria in their tissues and act as passive carriers of pathogens to humans. Bacterial persistence inside bivalves depends, at least in part, on hemolymph anti-bacterial activity that is exerted by both serum soluble factors and phagocytic cells (i.e., the hemocytes. It was previously shown that Mytilus galloprovincialis hemolymph serum contains opsonins that mediate D-mannose-sensitive interactions between hemocytes and V. cholerae O1 El Tor bacteria that carry the Mannose–Sensitive Hemagglutinin (MSHA. These opsonins enhance phagocytosis and killing of vibrios by facilitating their binding to hemocytes. Since V. cholerae strains not carrying the MSHA ligand (O1 classical, non O1/O139 are present in coastal water and can be entrapped by mussels, we studied whether in mussel serum, in addition to opsonins directed towards MSHA, other components can mediate opsonization of these bacteria. By comparing interactions of O1 classical and non O1/O139 strains with hemocytes in ASW and serum, it was found that M. galloprovincialis serum contains components that increase by at approximately two fold their adhesion to, association with and killing by hemocytes. Experiments conducted with high and low molecular mass fractions obtained by serum ultrafiltration indicated that these compounds have molecular mass higher than 5000 Da. Serum exposure to high temperature (80°C abolished its opsonizing capability suggesting that the involved serum active components are of protein nature. Further studies are needed to define the chemical properties and specificity of both the involved bacterial ligands and hemolymph opsonins. This information will be central not only to better understand V. cholerae ecology, but also to improve current bivalve depuration practices and properly protect human health.

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

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Verena Olivier

2009-10-01

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.

[VNTR-genotyping of Vibrio cholerae strains isolated from objects in the territory of Russian Federation in 2012].

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Vodop'ianov, A S; Mazrukho, A B; Vodop'ianov, S O; Mishan'kin, B N; Kruglikov, V D; Apkhangel'skaia, I V; Oleĭnikov, I P; Zubkova, D A; Monakhova, E V; Grigorenko, L V

2014-01-01

VNTR-typing of Vibrio cholerae strains isolated in the territory of Russian Federation in 2012. 71 Vibrio cholerae O3 and 3 V cholerae O1/O139 strains were used in the study. Genotyping was performed by using PCR for 5 VNTR-loci. Multilocus VNTR-typing allowed to group the strains into 31 VNTR-genotypes. Genotypes were divided among 10 discrete clusters by results of a cluster analysis. The presence of tcpA gene is clearly linked with the presence of VcB locus. Each geographic region was characterized by their own VNTR-genotypes. In the course of the carried out VNTR-genotyping of V. cholerae isolated in 2012, 2 types of vibrio population formation were detected. A geographic attachment to specific regions was characteristic for most of the genotypes.

Distribution and content of class 1 integrons in different Vibrio cholerae O-serotype strains isolated in Thailand

DEFF Research Database (Denmark)

Dalsgaard, Anders; Forslund, Anita; Serichantalergs, Oralak

2000-01-01

only a single antibiotic resistance gene. Although resistance genes in class 1 integrons were found in strains from the same epidemic, as well as in unrelated non-O1, non-O139 strains isolated from children with diarrhea, they were found to encode only some of the antibiotic resistance expressed...

Pandemic serotypes of Vibrio cholerae isolated from ships' ballast tanks and coastal waters: assessment of antibiotic resistance and virulence genes (tcpA and ctxA).

Science.gov (United States)

Dobbs, Fred C; Goodrich, Amanda L; Thomson, Frank K; Hynes, Wayne

2013-05-01

There is concern that ships' ballasting operations may disseminate Vibrio cholerae to ports throughout the world. Given evidence that the bacterium is indeed transported by ships, we isolated pandemic serotypes O1 and O139 from ballast tanks and characterized them with respect to antibiotic resistance and virulence genes ctxA and tcpA. We carried out concurrent studies with V. cholerae isolated from coastal waters. Of 284 isolates, 30 were serotype O1 and 59 were serotype O139. These serotypes were overrepresented in ballast tanks relative to the coastal waters sampled. All locations, whether coastal waters or ballast tanks, yielded samples from which serotype O1, O139, or both were isolated. There were three groups among the 62 isolates for which antibiotic characterization was conclusive: those exhibiting β-lactamase activity and resistance to at least one of the 12 antibiotics tested; those negative for β-lactamase but having antibiotic resistance; those negative for β-lactamase and registering no antibiotic resistance. When present, antibiotic resistance in nearly all cases was to ampicillin; resistance to multiple antibiotics was uncommon. PCR assays revealed that none of the isolates contained the ctxA gene and only two isolates, one O139 and one O1, contained the tcpA gene; both isolates originated from ballast water. These results support the bacteriological regulations proposed by the International Maritime Association for discharged ballast water.

Culture supernatants from V. cholerae O1 ElTor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity Cepas de V. cholerae O1 biotipo ElTor aisladas de diferente origen geográfico inducen vacuolización celular y citotoxicidad

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Jorge E Vidal

2009-02-01

Full Text Available OBJECTIVE: To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. MATERIAL AND METHODS: Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. RESULTS: All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+ and a non-toxigenic Mexican strain (CM 91-3, ctxAB-. Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. CONCLUSION: The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.OBJETIVO: Analizar el efecto vacuolizante de cepas de V. cholerae O1 ElTor aisladas de diferente origen geográfico, incluyendo México. MATERIAL Y MÉTODOS: Se realizaron pruebas de hemolisis, vacuolización y citotoxicidad en células Vero, así como PCR, análisis por RFLP y clonación molecular. RESULTADOS: Todas las cepas indujeron el efecto vacuolizante. Las cepas del ribotipo 2, aisladas de las costas del Golfo en Estados Unidos, presentaron títulos altos de vacuolización. El gen hlyA fue amplificado en las nueve cepas mediante PCR, aunque sólo ocho fueron hemolíticas. Se clonó el gen hlyA de una cepa toxigénica (2514-88, ctxAB+ y de una cepa no toxigénica aislada en México (CM 91-3, ctxAB-. El sobrenadante de las clonas recombinantes indujo hemólisis, efecto vacuolizante y citotoxicidad. El RFLP mostró alta similitud del gen hlyA de las cepas estudiadas. CONCLUSIÓN: El efecto vacuolizante es un

A simple filtration method to remove plankton-associated Vibrio cholerae in raw water supplies in developing countries.

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Huq, A; Xu, B; Chowdhury, M A; Islam, M S; Montilla, R; Colwell, R R

1996-07-01

Plankton to which cells of Vibrio cholerae O1 and/or O139 were attached was introduced into 0.5% Instant Ocean microcosms maintained at 25 degrees C. The bulk of the plankton and associated particulates was removed with a filter constructed from either nylon net and one of several different types of sari material, the latter being very inexpensive and readily available in villages in Bangladesh, where V. cholerae is endemic. V. cholerae was enumerated before and after filtration to evaluate the efficiency of the filtration procedure. The results obtained indicate that 99% of V. cholerae, i.e., those cells attached to plankton, were removed from the water samples. Epidemic strains of V. cholerae O1 and O139 from various geographical sources, including Bangladesh, Brazil, India, and Mexico, were included in the experiments. Removal of vibrios from water by this simple filtration method was found to yield consistent results with all strains examined in this study. Thus, it is concluded that a simple filtration procedure involving the use of domestic sari material can reduce the number of cholera vibrios attached to plankton in raw water from ponds and rivers commonly used for drinking. Since untreated water from such sources serves as drinking water for millions of people living in developing countries (e.g., Bangladesh), filtration should prove effective at reducing the incidence and severity of outbreaks, especially in places that lack fuel wood for boiling water and/or municipal water treatment plants. The results of this study provide the basis for determining such reductions, which are to be carried out in the near future.

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

DEFF Research Database (Denmark)

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

patients was co-infected with two V. cholerae strains (VC-1 and VC-3). Major virulence factors, biotype and antimicrobial resistance genes were identified by WGS. A global phylogenetic tree was inferred using genome wide SNPs (Single Nucleotide Polymorphism) analysis. RESULTS: All the V. cholerae strains...

A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh.

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Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B; Tasnimuzzaman, Md; Nordland, Andreas; Begum, Anowara; Jensen, Peter K M

2018-01-01

Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae ( V. cholerae ) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from "point-of-drinking" and "source" in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds ( P source [OR = 17.24 (95% CI = 7.14-42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds ( p source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point

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

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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 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

Detection of Vibrio parahaemolyticus and Vibrio cholerae in oyster, Crassostrea rhizophorae, collected from a natural nursery in the Cocó river estuary, Fortaleza, Ceará, Brazil Isolamento de Vibrio parahaemolyticus e Vibrio cholerae em ostras, Crassostrea rhizophorae, coletadas em um criadouro natural no estuário do rio Cocó, Fortaleza, Ceará, Brasil

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Oscarina Viana de Sousa

2004-04-01

Full Text Available Oysters are edible organisms that are often ingested partially cooked or even raw, presenting therefore a very high risk to the consumers' health, especially in tropical regions. The presence of Vibrio cholerae and Vibrio parahaemolyticus in oysters sampled at an estuary in the Brazilian northeastern region was studied, with 300 oysters tested through an 8-months period. The salinity of the water at the sampling point varied between 3% and 27‰. V. cholerae was the most frequently detected species (33.3% of the samples, and of the 22 V. cholerae isolates, 20 were identified as non-O1/non-O139, with two of the colonies presenting a rough surface and most of remaining ones belonging to the Heiberg II fermentation group. V. parahaemolyticus was isolated from just one of the samples. Other bacteria such as Providencia spp., Klebsiella spp. and Morganella morganii were also isolated.As ostras são alimentos marinhos freqüentemente ingeridos crus ou parcialmente cozidos. Por esta razão, o risco para a saúde dos consumidores desses produtos é muito elevado, principalmente, quando são de regiões tropicais. Foi estudada a presença de Vibrio cholerae e Vibrio parahaemolyticus em ostras de um estuário na região Nordeste do Brasil. Trezentas ostras foram analisadas, em um período de 8 meses. A salinidade da água, no local de coleta, variou de 3 a 27‰. V. cholerae foi o vibrio mais freqüentemente detectado (33,3% das amostras. Dos 22 isolados, 20 foram identificados como V. cholerae não-O1/não-O139, duas delas apresentando forma rugosa sendo a maioria das demais pertencente ao tipo fermentativo Heiberg II. V. parahaemolyticus foi isolado em apenas umas das coletas. Foram, também, identificadas nas amostras isolados de Providencia spp., Klebsiella spp., Proteus spp. e Morganella morganii.

Zinc oxide nanoparticles provide anti-cholera activity by disrupting the interaction of cholera toxin with the human GM1 receptor.

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Sarwar, Shamila; Ali, Asif; Pal, Mahadeb; Chakrabarti, Pinak

2017-11-03

Vibrio cholerae causes cholera and is the leading cause of diarrhea in developing countries, highlighting the need for the development of new treatment strategies to combat this disease agent. While exploring the possibility of using zinc oxide (ZnO) nanoparticles (NPs) in cholera treatment, we previously found that ZnO NPs reduce fluid accumulation in mouse ileum induced by the cholera toxin (CT) protein. To uncover the mechanism of action of ZnO NPs on CT activity, here we used classical (O395) and El Tor (C6706) V. cholerae biotypes in growth and biochemical assays. We found that a ZnO NP concentration of 10 μg/ml did not affect the growth rates of these two strains, nor did we observe that ZnO NPs reduce the expression levels of CT mRNA and protein. It was observed that ZnO NPs form a complex with CT, appear to disrupt the CT secondary structure, and block its interaction with the GM1 ganglioside receptor in the outer leaflet of the plasma membrane in intestinal (HT-29) cells and thereby reduce CT uptake into the cells. In the range of 2.5-10 μg/ml, ZnO NPs exhibited no cytotoxicity on kidney (HEK293) and HT-29 cells. We conclude that ZnO NPs prevent the first step in the translocation of cholera toxin into intestinal epithelial cells without exerting measurable toxic effects on HEK293 and HT-29 cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Tipificación Molecular del Vibrio cholerae O1 en el Perú

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Huguet T José

2000-01-01

Full Text Available Este estudio de ribotipificación en 75 cepas de Vibrio cholerae O1 permitió identificar tres variantes ribotípicas, referidas como Per1, Per2 y Per3, aisladas durante el periodo 1991- 1999 en el Perú. La variante Per1 fue reportada tanto en la etapa epidémica y endémica del cólera, mientras que Per2 y Per3 se relacionaron sólo con la etapa endémica. Los resultados mostraron además una aparición constante y mayoritaria de la variante Per1, poniendo en evidencia la emergencia de un mismo grupo clonal en los brotes epidémicos del Perú. Las variantes ribotípicas encontradas fueron comparadas con los ribotipos de diferentes cepas referenciales de V. cholerae previamente caracterizadas. Se observó una identidad total del ribotipo Per1 con la variante ribotípica de aislamientos Asiáticos (Tailandia, encontrándose además altos índices de similitud entre los ribotipos Per1, Per2 y Per3, y evidenciándose una estrecha relación entre las cepas peruanas y los aislamientos asiáticos.

Detection of Salmonella Spp., Shigella (Flexneri and Sonnei) and Vibrio Cholerae O1 by Polymerase Chain Reaction (PCR) in Exported Shrimp from the Mexican Northeast Coast

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Perez, L.; Nuñez, F.; Rubio, M.; Nicoli, M. [Universidad Nacional Autónoma de México, Facultad de Medicina Veterinaria y Zootecnia (Mexico)

2005-01-15

The objective of the present work was to use the PCR technique for the simultaneous detection of Salmonella spp and Vibrio cholerae O1 in frozen shrimp for export. The DNA segments located in the gene A [284 pairs of bases (pb)] from Salmonella spp. locus ial (217 and 320 pb) from Shigella flexneri and Shigella sonnei and the gene ctxA and ctxB (777 pb) from Vibrio cholerae O1 were amplified. The different primers that amplify these segments were assayed in a PCR reaction for the simultaneous detection of DNA from the microorganisms. It was not possible to amplify the gene of Shigella sonnei and Shigella flexneri under the assay’s conditions, whilst those of Salmonella spp. and Vibrio cholerae O1 were successfully amplified. The amplification conditions for the PCR were: 94° C, 58° C and 72° C during 30 cycles, allowing a reduction from 15 days test time with the official microbiological methods to 28 hours (24 for the pre-enrichment and four for the PCR). Samples of raw-frozen-headless shrimps were taken from production plants located in the State of Sinaloa, Mexico. A random sampling procedure was used, according to the guidelines described by the International Commission of Microbiological Specifications for Foods (ICMSF, 1999). Five packages per lot per production plant were obtained. From each individual package (5 pounds 80 OZ ≈ 2.27 kg) three samples were taken for the bacteriological assays to search for Salmonella spp. and Vibrio cholerae O1, respectively. The samples were also analyzed by PCR. Results showed that none of the samples were positive by PCR to any of the studied bacteria. Salmonella spp. and Vibrio cholerae O1 were not detected in these samples by the official methods. However, the latter were able to identify other Vibrio species and enterobacteria like Proteus and Acromobacter. These results confirmed PCR’s rapidity, sensitivity and specificity. (author)

Culture supernatants from V. cholerae O1 El Tor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity.

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Vidal, Jorge E; Enríquez-Rincón, Fernando; Giono-Cerezo, Silvia; Ribas-Aparicio, Rosa María; Figueroa-Arredondo, Paula

2009-01-01

To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+) and a non-toxigenic Mexican strain (CM 91-3, ctxAB-). Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.

Surface and virulence properties of environmental Vibrio cholerae non-O1 from Albufera Lake (Valencia, Spain).

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Amaro, C; Toranzo, A E; González, E A; Blanco, J; Pujalte, M J; Aznar, R; Garay, E

1990-04-01

A total of 140 environmental Vibrio cholerae non-O1 isolates, together with several culture collection strains from both environmental and clinical sources, were studied in relation to hemagglutination, surface hydrophobicity, and the enzymatic, hemolytic, cytotoxic, and enterotoxic activities of their extracellular products. A total of 78 and 62% of the strains produced hemagglutinins and exohemagglutinins, respectively. Four different hemagglutinating and two exohemagglutinating activities were found by using eight sugars in the inhibition assays. Cell-bound mannose-sensitive hemagglutination was detected mainly in chicken blood, whereas fucose-sensitive hemagglutination was recorded only in human blood. Cell-bound hemagglutinin resistant to all sugars tested was the only one related to surface hydrophobicity. The surface properties varied along the growth curves. The non-O1 strains displayed strong enzymatic and hemolytic activities, except for esculin hydrolysis. Of 26 non-O1 isolates selected for cytotoxin and enterotoxin production, 23 showed a wide spectrum of cytotoxic effects on cell lines of poikilothermic and homoiothermic species, but they were weakly enterotoxigenic in the infant mouse test. All extracellular products of cytotoxic strains were proteolytic, lipolytic, and hemolytic, and a high percentage produced hemagglutination of chicken blood. The cytotoxic factors in the non-O1 strains analyzed were not R plasmid mediated.

The increased severity in patients presenting to hospital with diarrhea in Dhaka, Bangladesh since the emergence of the hybrid strain of Vibrio cholerae O1 is not unique to cholera patients.

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Chowdhury, Fahima; Kuchta, Alison; Khan, Ashraful Islam; Faruque, A S G; Calderwood, Stephen B; Ryan, Edward T; Qadri, Firdausi

2015-11-01

A hybrid strain of Vibrio cholerae O1 El Tor that expresses a classical cholera toxin (CT) emerged in 2001. This hybrid variant rapidly replaced the previous El Tor strain around the world. The global emergence of this variant coincided with anecdotal reports that cholera patients were presenting with more severe dehydration and disease in many locations. A comparison was made of the severity of disease before and after the emergence of the hybrid strain in cholera patients attending an icddr,b hospital in Dhaka, Bangladesh. It was found that cholera patients presented with more severe dehydration and severe disease in the later period. However, this was also true for all non-cholera patients as well. In addition, in sub-analyses of patients who presented with rotavirus and enterotoxigenic Escherichia coli (ETEC), similar results were found. Comparing the two periods for differences in patient characteristics, nutritional status, vaccination status, and income, no plausible cause for patients presenting with more severe disease was identified in the later period. As a shift in severity for both cholera and non-cholera was observed, these results indicate that the altered El Tor strain cannot fully explain the difference in cholera severity before and after 2001. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

OpenAIRE

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

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...

Cólera e condições de vida da população Cholera and living conditions, Brazil

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Moacir Gerolomo

2000-08-01

Full Text Available INTRODUÇÃO: Fatores relacionados às condições de vida da população e condições ambientais precárias são freqüentemente citados como os maiores obstáculos para o controle de surtos e epidemias por cólera. Nesse sentido, realizou-se estudo com o objetivo de avaliar o peso de fatores referentes às condições de vida da população, relacionando questões ambientais com a instalação e o impacto da cólera. MÉTODO: Através de uma regressão linear múltipla, pelo método "backward stepwise", com influência do investigador, foram correlacionados os indicadores socioeconômicos com as taxas de incidência por cólera observadas nos municípios do Estado de Pernambuco, no ano de 1992. RESULTADOS/CONCLUSÕES: O modelo ajustado indica que a proporção de domicílios que utilizam água não proveniente de uma rede geral é a variável que tem maior peso na flutuação positiva das taxas de incidência de cólera. As variáveis "proporção de domicílios não ligados à rede geral de esgotos" e "proporção de chefes de família com renda igual ou menor do que um salário-mínimo mensal" também se associam positivamente, com coeficientes de regressão estatisticamente significativos, às taxas de incidência de cólera. A proporção de domicílios sem nenhuma instalação sanitária, por outro lado, se associa negativamente às taxas de incidência de cólera, sugerindo que instalações sanitárias, sem existência de rede de esgoto, aumentam o risco de contaminação ambiental. Os resultados apontam que a maior prioridade em saneamento é a oferta de água de boa qualidade.INTRODUCTION: Factors associated with precarious living and environmental conditions are frequently cited as major obstacles for the control of cholera outbreaks and epidemics. The purposes of the study are to evaluate the contribution of factors associated with the population living conditions and correlate the environmental problems with the onset of cholera

[Antibiotic resistance pattern of 24, 526 strains of Vibrio cholerae O1 isolated in Mexico from 1991 to 1993].

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Giono-Cerezo, S; Zárate, A; Gutiérrez, L; Valdespino, J L

1994-01-01

Profile of antimicrobial resistance by Kirby-Bauer method was performed on 24526 Vibrio cholerae O1 strains isolated in México (1991-1993) from fecal swabs in cholera cases and from asymptomatic carriers. Minimal inhibitory concentration (MIC) tests for tetracycline (Te) and doxycycline (D) were done on selected strains. Single antibiotic discs were used at concentrations of: Te, 30 micrograms; D, 30 micrograms; erythromycin (E), 15 micrograms; chloramphenicol (CM), 30 micrograms; ampicillin (AM), 10 micrograms; trimethoprim-sulfamethoxazole (SXT) 1.25 micrograms/23.75 micrograms. Strains whose halos were of a smaller diameter than the intermediate value were considered resistant. It is important to maintain surveillance on antimicrobial susceptibility as epidemiological marker on geographical selected areas in order to detect changes of resistant patterns.

Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador.

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Ryan, Sadie J; Stewart-Ibarra, Anna M; Ordóñez-Enireb, Eunice; Chu, Winnie; Finkelstein, Julia L; King, Christine A; Escobar, Luis E; Lupone, Christina; Heras, Froilan; Tauzer, Erica; Waggoner, Egan; James, Tyler G; Cárdenas, Washington B; Polhemus, Mark

2018-03-10

Cholera emergence is strongly linked to local environmental and ecological context. The 1991-2004 pandemic emerged in Perú and spread north into Ecuador's El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae , by polymerase chain reaction (PCR). We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera-estuarine system to anticipate potential future cholera outbreaks.

Avaliação de desinfetantes químicos de uso doméstico contra Vibrio cholerae EL TOR (amostra não toxigênica

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Timenetsky Jorge

1992-01-01

Full Text Available As metodologias de avaliação microbiológica de desinfetantes são permanentemente questionadas porque os protocolos laboratoriais não representam as condições reais de uso desses produtos. Em 1985, adotou-se no Brasil, a metodologia da Diluição-Uso da AOAC, para a qualificação microbiológica de desinfetantes químicos, para fins comerciais. Desta maneira, os desinfetantes domésticos são testados contra amostras padrões de Salmonella choleraesuis e Staphylococcus aureus. Pesquisou-se o emprego de Vibrio cholerae devido a sua atual importância, no Brasil, em termos de Saúde Pública, associada ao estudo da atividade antimicrobiana de desinfetantes. Dezenove produtos desinfetantes de uso doméstico encontrados no comércio foram microbiologicamente avaliados. A metodologia foi a Diluição-Uso com 10 carreadores. Os compostos ativos dos produtos incluíam: formaldeído, fenóis, cresóis, amônio quaternário, cloro e etanol, sendo que sete, eram de composição associada. Conforme as recomendações de uso, dezesseis produtos, devem ser utilizados sem diluição. Nestas condições, 9 desinfetantes foram vibriocidas e sete não revelaram tal atividade antibacteriana. Quatro produtos em diluições não esclarecedoras para a desinfecção também mostraram-se ineficazes. Os produtos vibriocidas que devem ser utilizados sem diluição, foram reavaliados diluídos ao dobro. Estas soluções não inativaram V.cholerae, demonstrando microbiologicamente que os seus compostos ativos estão em concentrações limítrofes. O álcool comercial (95,5degrees GL a 1:3, a "água sanitária" (2,8% de cloro ativo a 1:200, creolina a 1:10 e o "Lysoform" a 1:20 atingiram os padrões do teste.

Avaliação de desinfetantes químicos de uso doméstico contra Vibrio cholerae EL TOR (amostra não toxigênica Evaluation of the effect of chemical domestic disinfectants on Vibrio cholerae EL TOR (non toxigenic strain

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Jorge Timenetsky

1992-10-01

Full Text Available As metodologias de avaliação microbiológica de desinfetantes são permanentemente questionadas porque os protocolos laboratoriais não representam as condições reais de uso desses produtos. Em 1985, adotou-se no Brasil, a metodologia da Diluição-Uso da AOAC, para a qualificação microbiológica de desinfetantes químicos, para fins comerciais. Desta maneira, os desinfetantes domésticos são testados contra amostras padrões de Salmonella choleraesuis e Staphylococcus aureus. Pesquisou-se o emprego de Vibrio cholerae devido a sua atual importância, no Brasil, em termos de Saúde Pública, associada ao estudo da atividade antimicrobiana de desinfetantes. Dezenove produtos desinfetantes de uso doméstico encontrados no comércio foram microbiologicamente avaliados. A metodologia foi a Diluição-Uso com 10 carreadores. Os compostos ativos dos produtos incluíam: formaldeído, fenóis, cresóis, amônio quaternário, cloro e etanol, sendo que sete, eram de composição associada. Conforme as recomendações de uso, dezesseis produtos, devem ser utilizados sem diluição. Nestas condições, 9 desinfetantes foram vibriocidas e sete não revelaram tal atividade antibacteriana. Quatro produtos em diluições não esclarecedoras para a desinfecção também mostraram-se ineficazes. Os produtos vibriocidas que devem ser utilizados sem diluição, foram reavaliados diluídos ao dobro. Estas soluções não inativaram V.cholerae, demonstrando microbiologicamente que os seus compostos ativos estão em concentrações limítrofes. O álcool comercial (95,5° GL a 1:3, a "água sanitária" (2,8% de cloro ativo a 1:200, creolina a 1:10 e o "Lysoform" a 1:20 atingiram os padrões do teste.The methodology of microbiological evaluation of disinfectants is permanently being questioned because the laboratorial protocols do not correspond to the real conditions under which these products are used. In 1985 the Use-Dilution method of AOAC was adopted in

Sequences of a co-existing SXT element, a chromosomal integron (CI) and an IncA/C plasmid and their roles in multidrug resistance in a Vibrio cholerae O1 El Tor strain.

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Wang, Ruibai; Li, Jie; Kan, Biao

2016-09-01

The ongoing seventh cholera pandemic is attributed to Vibrio cholerae O1 El Tor biotype strains. Although antibiotic therapy ameliorates symptoms in patients and reduces pathogen transfer to the environment, multidrug resistance remains a major clinical threat. An O1 El Tor strain isolated from a patient in 1998 was intermediate or resistant to 13 antibiotics and could potentially produce extended-spectrum β-lactamase (ESBL), which is very rare in O1 strains. Using genome sequencing, three relevant genetic elements were identified in this strain: a hybrid SXT element (ICEVchCHN1307); a new IncA/C plasmid (pVC1307); and a chromosomal integron. Twenty antibiotic resistance genes were located on them, including blaTEM-1, blaCTX-M-14 and phenotypically silenced tetRA genes. These data elucidate the role of individual genetic components in antibiotic resistance and the accumulation of drug resistance genes in V. cholerae. Copyright © 2016. Published by Elsevier B.V.

Cholera forecast for Dhaka, Bangladesh, with the 2015-2016 El Niño: Lessons learned

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Martinez, Pamela P.; Reiner, Robert C.; Cash, Benjamin A.; Rodó, Xavier; Shahjahan Mondal, Mohammad; Roy, Manojit; Yunus, Mohammad; Faruque, A. S. G.; Huq, Sayeeda; King, Aaron A.; Pascual, Mercedes

2017-01-01

A substantial body of work supports a teleconnection between the El Niño-Southern Oscillation (ENSO) and cholera incidence in Bangladesh. In particular, high positive anomalies during the winter (Dec-Feb) in sea surface temperatures (SST) in the tropical Pacific have been shown to exacerbate the seasonal outbreak of cholera following the monsoons from August to November. Climate studies have indicated a role of regional precipitation over Bangladesh in mediating this long-distance effect. Motivated by this previous evidence, we took advantage of the strong 2015–2016 El Niño event to evaluate the predictability of cholera dynamics for the city in recent times based on two transmission models that incorporate SST anomalies and are fitted to the earlier surveillance records starting in 1995. We implemented a mechanistic temporal model that incorporates both epidemiological processes and the effect of ENSO, as well as a previously published statistical model that resolves space at the level of districts (thanas). Prediction accuracy was evaluated with “out-of-fit” data from the same surveillance efforts (post 2008 and 2010 for the two models respectively), by comparing the total number of cholera cases observed for the season to those predicted by model simulations eight to twelve months ahead, starting in January each year. Although forecasts were accurate for the low cholera risk observed for the years preceding the 2015–2016 El Niño, the models also predicted a high probability of observing a large outbreak in fall 2016. Observed cholera cases up to Oct 2016 did not show evidence of an anomalous season. We discuss these predictions in the context of regional and local climate conditions, which show that despite positive regional rainfall anomalies, rainfall and inundation in Dhaka remained low. Possible explanations for these patterns are given together with future implications for cholera dynamics and directions to improve their prediction for the city

Cholera forecast for Dhaka, Bangladesh, with the 2015-2016 El Niño: Lessons learned.

Science.gov (United States)

Martinez, Pamela P; Reiner, Robert C; Cash, Benjamin A; Rodó, Xavier; Shahjahan Mondal, Mohammad; Roy, Manojit; Yunus, Mohammad; Faruque, A S G; Huq, Sayeeda; King, Aaron A; Pascual, Mercedes

2017-01-01

A substantial body of work supports a teleconnection between the El Niño-Southern Oscillation (ENSO) and cholera incidence in Bangladesh. In particular, high positive anomalies during the winter (Dec-Feb) in sea surface temperatures (SST) in the tropical Pacific have been shown to exacerbate the seasonal outbreak of cholera following the monsoons from August to November. Climate studies have indicated a role of regional precipitation over Bangladesh in mediating this long-distance effect. Motivated by this previous evidence, we took advantage of the strong 2015-2016 El Niño event to evaluate the predictability of cholera dynamics for the city in recent times based on two transmission models that incorporate SST anomalies and are fitted to the earlier surveillance records starting in 1995. We implemented a mechanistic temporal model that incorporates both epidemiological processes and the effect of ENSO, as well as a previously published statistical model that resolves space at the level of districts (thanas). Prediction accuracy was evaluated with "out-of-fit" data from the same surveillance efforts (post 2008 and 2010 for the two models respectively), by comparing the total number of cholera cases observed for the season to those predicted by model simulations eight to twelve months ahead, starting in January each year. Although forecasts were accurate for the low cholera risk observed for the years preceding the 2015-2016 El Niño, the models also predicted a high probability of observing a large outbreak in fall 2016. Observed cholera cases up to Oct 2016 did not show evidence of an anomalous season. We discuss these predictions in the context of regional and local climate conditions, which show that despite positive regional rainfall anomalies, rainfall and inundation in Dhaka remained low. Possible explanations for these patterns are given together with future implications for cholera dynamics and directions to improve their prediction for the city.

Phylodynamic analysis of clinical and environmental Vibrio cholerae isolates from Haiti reveals diversification driven by positive selection.

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Azarian, Taj; Ali, Afsar; Johnson, Judith A; Mohr, David; Prosperi, Mattia; Veras, Nazle M; Jubair, Mohammed; Strickland, Samantha L; Rashid, Mohammad H; Alam, Meer T; Weppelmann, Thomas A; Katz, Lee S; Tarr, Cheryl L; Colwell, Rita R; Morris, J Glenn; Salemi, Marco

2014-12-23

Phylodynamic analysis of genome-wide single-nucleotide polymorphism (SNP) data is a powerful tool to investigate underlying evolutionary processes of bacterial epidemics. The method was applied to investigate a collection of 65 clinical and environmental isolates of Vibrio cholerae from Haiti collected between 2010 and 2012. Characterization of isolates recovered from environmental samples identified a total of four toxigenic V. cholerae O1 isolates, four non-O1/O139 isolates, and a novel nontoxigenic V. cholerae O1 isolate with the classical tcpA gene. Phylogenies of strains were inferred from genome-wide SNPs using coalescent-based demographic models within a Bayesian framework. A close phylogenetic relationship between clinical and environmental toxigenic V. cholerae O1 strains was observed. As cholera spread throughout Haiti between October 2010 and August 2012, the population size initially increased and then fluctuated over time. Selection analysis along internal branches of the phylogeny showed a steady accumulation of synonymous substitutions and a progressive increase of nonsynonymous substitutions over time, suggesting diversification likely was driven by positive selection. Short-term accumulation of nonsynonymous substitutions driven by selection may have significant implications for virulence, transmission dynamics, and even vaccine efficacy. Cholera, a dehydrating diarrheal disease caused by toxigenic strains of the bacterium Vibrio cholerae, emerged in 2010 in Haiti, a country where there were no available records on cholera over the past 100 years. While devastating in terms of morbidity and mortality, the outbreak provided a unique opportunity to study the evolutionary dynamics of V. cholerae and its environmental presence. The present study expands on previous work and provides an in-depth phylodynamic analysis inferred from genome-wide single nucleotide polymorphisms of clinical and environmental strains from dispersed geographic settings in

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

International Nuclear Information System (INIS)

Naseer, M.; Jamali, T.

2014-01-01

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

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

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Liliana Candida Dengo-Baloi

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

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

Science.gov (United States)

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

2017-01-01

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

Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador

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Sadie J. Ryan

2018-03-01

Full Text Available Cholera emergence is strongly linked to local environmental and ecological context. The 1991–2004 pandemic emerged in Perú and spread north into Ecuador’s El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae, by polymerase chain reaction (PCR. We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera–estuarine system to anticipate potential future cholera outbreaks.

El Tor hemolysin of Vibrio cholerae O1 forms channels in planar lipid bilayer membranes.

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Ikigai, H; Ono, T; Iwata, M; Nakae, T; Shimamura, T

1997-05-15

We investigated the channel formation by El Tor hemolysin (molecular mass, 65 kDa) of Vibrio cholerae O1 biotype El Tor in planar lipid bilayers. The El Tor hemolysin channel exhibited asymmetric and hyperbolic membrane current with increasing membrane potential, meaning that the channel is voltage dependent. The zero-current membrane potential measured in KCI solution showed that permeability ratio PK+/PCl- was 0.16, indicating that the channel is 6-fold more anion selective over cation. The hemolysin channel frequently flickered in the presence of divalent cations, suggesting that the channel spontaneously opens and closes. These data imply that the El Tor hemolysin damages target cells by the formation of transmembrane channels and, consequently, is the cause of osmotic cytolysis.

Outbreak of Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor strain--La Huasteca Region, Mexico, 2013.

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Díaz-Quiñonez, Alberto; Hernández-Monroy, Irma; Montes-Colima, Norma; Moreno-Pérez, Asunción; Galicia-Nicolás, Adriana; Martínez-Rojano, Hugo; Carmona-Ramos, Concepción; Sánchez-Mendoza, Miroslava; Rodríguez-Martínez, José Cruz; Suárez-Idueta, Lorena; Jiménez-Corona, María Eugenia; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo

2014-06-27

On September 2 and 6, 2013, Mexico's National System of Epidemiological Surveillance identified two cases of cholera in Mexico City. Rectal swab cultures from both patients were confirmed as toxigenic Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Pulsed-field gel electrophoresis and virulence gene amplification (ctxA, ctxB, zot, and ace) demonstrated that the strains were identical to one another but different from strains circulating in Mexico previously. The strains were indistinguishable from the strain that has caused outbreaks in Haiti, the Dominican Republic, and Cuba. The strain was susceptible to doxycycline, had intermediate susceptibility to ampicillin and chloramphenicol, was less than fully susceptible to ciprofloxacin, and was resistant to furazolidone and trimethoprim-sulfamethoxazole. An investigation failed to identify a common source of infection, additional cases, or any epidemiologic link between the cases. Both patients were treated with a single, 300-mg dose of doxycycline, and their symptoms resolved.

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

Science.gov (United States)

Boucher, Yan

2016-05-03

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. Copyright © 2016 Boucher.

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

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Yan Boucher

2016-07-01

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

Cholera in endemic districts in Uganda during El Niño rains: 2002 ...

African Journals Online (AJOL)

Background: El Niño phenomenon causing increased rainfall and flooding has been linked to flare ups and emergence of several disease outbreaks including cholera. The latter has been reported in many districts in Uganda in recent years. Therefore an understanding of factors influencing its pattern of occurrence is ...

Vigilancia en red de los serotipos y la susceptibilidad antimicrobiana de Salmonella spp., Shigella spp. Y Vibrio cholerae O1, 1997 - 1999

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Nélida Muñoz

2000-09-01

Full Text Available En 1997, el Grupo de Microbiología del INS estableció un programa en red con los Laboratorios de Salud Pública (LSP del país y el apoyo de la OPS, para la vigilancia de los principales patógenos causantes de enfermedad diarreica aguda. El objetivo fue conocer los serotipos y los patrones de resistencia antimicrobiana de Salmonella spp., Shigella spp. y Vibrio cholerae O1. Los aislamientos fueron confirmados de acuerdo con los esquemas de identificación bioquímica y serológica estandarizados y la determinación de la susceptibilidad antimicrobiana se realizó por la técnica de difusión de disco (Kirby-Bauer. De 1997 a 1999, participaron 22 LSP con el envio de 976 aislamientos, 96% de origen clínico y 4% de alimentos; 34% Salmonella spp., 23% Shigella spp. y 42% V. cholerae 01. La distribución por serotipo de Salmonella fue 39% S. Enteritidis, 27% S. Typhimurium, 9% grupo El, 5% S. Typhi y 20% otros serotipos; de los aislamientos de Shigella, 67% fueron S. grupo flexneriza, 30% S sonnei, 2% S. dysenteriae y 1% S. boydii. Para V. cholerae 01, 99% fue serotipo Ogawa. La susceptibilidad antimicrobiana determinó que 56% de los aislamientos de Salmonella eran resistentes y 22% multirresistentes, con un patrón predominante de ampicilina, tetraciclina y trimetoprim-sulfa (SXT. De los aislamientos de Shigella, 97% fueron resistentes y 57% multirresistentes, con un patrón de ampicilina, tetraciclina, cloranfenicol y SXT. No se observaron cambios en la susceptibilidad de V. cholerae O1. Este estudio enfatiza la importancia de continuar con el programa de vigilancia, para conocer la epidemiologia de la EDA en Colombia, darle un tratamiento óptimo a estas infecciones y poder diseñar programas para disminuir la diseminación de bacterias resistentes.

A factor converting viable but nonculturable Vibrio cholerae to a culturable state in eukaryotic cells is a human catalase.

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Senoh, Mitsutoshi; Hamabata, Takashi; Takeda, Yoshifumi

2015-08-01

In our previous work, we demonstrated that viable but nonculturable (VBNC) Vibrio cholerae O1 and O139 were converted to culturable by coculture with eukaryotic cells. Furthermore, we isolated a factor converting VBNC V. cholerae to culturable (FCVC) from a eukaryotic cell line, HT-29. In this study, we purified FCVC by successive column chromatographies comprising UNO Q-6 anion exchange, Bio-Scale CHT2-1 hydroxyapatite, and Superdex 200 10/300 GL. Homogeneity of the purified FCVC was demonstrated by SDS-PAGE. Nano-LC MS/MS analysis showed that the purified FCVC was a human catalase. An experiment of RNAi knockdown of catalase mRNA from HT-29 cells and treatment of the purified FCVC with a catalase inhibitor, 3-amino-1,2,4-triazole confirmed that the FCVC was a catalase. A possible role of the catalase in converting a VBNC V. cholerae to a culturable state in the human intestine is discussed. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

The molecular epidemiology of cholera in Latin America.

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Wachsmuth, I K; Evins, G M; Fields, P I; Olsvik, O; Popovic, T; Bopp, C A; Wells, J G; Carrillo, C; Blake, P A

1993-03-01

To explain the sudden appearance and rapid spread of cholera in Latin America in January 1991, molecular techniques were used to define Vibrio cholerae O1 isolates from around the world. Restriction fragment length polymorphisms of rRNA and ctxA genes, DNA sequence of cholera toxin B subunit gene ctxB, and multilocus enzyme electrophoresis data were used to characterize 197 isolates. Worldwide, there are at least four distinct toxigenic El Tor V. cholerae O1 clones: the seventh pandemic (Eastern Hemisphere), US Gulf Coast, Australian, and Latin American. Nontoxigenic V. cholerae O1 previously isolated in Brazil, Mexico, and Peru are unlike current toxigenic isolates. The Latin American clone probably represents an extension of the seventh pandemic into the Western Hemisphere, while the US Gulf Coast clone most likely evolved separately. These data will be useful in monitoring the spread of cholera, determining the origin of outbreaks in both hemispheres, and implicating specific vehicles of transmission.

Molecular Characterization of Vibrio cholerae Isolated From Clinical Samples in Kurdistan Province, Iran.

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Ramazanzadeh, Rashid; Rouhi, Samaneh; Shakib, Pegah; Shahbazi, Babak; Bidarpour, Farzam; Karimi, Mohammad

2015-05-01

Vibrio cholerae causes diarrhoeal disease that afflicts thousands of people annually. V. cholerae is classified on the basis of somatic antigens into serovars or serogroups and there are at least 200 known serogroup. Two serogroups, O1 and O139 have been associated with epidemic diseases. Virulence genes of these bacteria are OmpW, ctxA and tcpA. Due to the importance of V. cholerae infection and developing molecular diagnostics of this organism in medical and microbiology sciences, this study aimed to describe molecular characterization of V. cholerae isolated from clinical samples using a molecular method. In this study, 48 samples were provided during summer 2013 (late August and early September) by reference laboratory. Samples were assessed using biochemical tests initially. The primer of OmpW, ctxA and tcpA genes was used in Polymerase Chain Reaction (PCR) protocols. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR and Repetitive Extragenic Palindromic (REP)-PCR methods were used to subtype V. cholerae. In this study, from a total of 48 clinical stool samples 39 (81.2 %) were positive for V. cholerae in biochemical tests and bacteria culture tests. The PCR results showed that of 39 positive isolates 35 (89.7%), 34 (87.1%) and 37 (94.8%) were positive for ctxA, tcpA and OmpW gene, respectively. Also, in the REP-PCR method with ERIC primer strains were divided into 10 groups. In the REP-PCR method with REP primer, strains were divided into 13 groups. Polymerase chain reaction has specificity and accuracy for identification of the organism and is able to differentiate biotypes. Enterobacterial repetitive intergenic consensus sequence is one of the informative and discriminative methods for the analysis of V. cholerae diversity. The REP-PCR is a less informative and discriminative method compared to other methods for the analysis of V. cholerae diversity.

Mechanism of membrane damage by El Tor hemolysin of Vibrio cholerae O1.

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Ikigai, H; Akatsuka, A; Tsujiyama, H; Nakae, T; Shimamura, T

1996-08-01

El Tor hemolysin (ETH; molecular mass, 65 kDa) derived from Vibrio cholerae O1 spontaneously assembled oligomeric aggregates on the membranes of rabbit erythrocyte ghosts and liposomes. Membrane-associated oligomers were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting into two to nine bands with apparent molecular masses of 170 to 350 kDa. ETH assembled oligomers on a liposomal membrane consisting of phosphatidylcholine and cholesterol, but not on a membrane of phosphatidylcholine alone. Cholesterol could be replaced with diosgenin or ergosterol but not with 5alpha-cholestane-3-one, suggesting that sterol is essential for the oligomerization. The treatment of carboxyfluorescein-encapsulated liposomes with ETH caused a rapid release of carboxyfluorescein into the medium. Because dextrin 20 (molecular mass, 900 Da) osmotically protected ETH-mediated hemolysis, this hemolysis is likely to be caused by pore formation on the membrane. The pore size(s) estimated from osmotic protection assays was in the range of 1.2 to 1.6 nm. The pore formed on a rabbit erythrocyte membrane was confirmed morphologically by electron microscopy. Thus, we provide evidence that ETH damages the target by the assembly of hemolysin oligomers and pore formation on the membrane.

Cloning, expression, purification, crystallization and preliminary X-ray analysis of a fructokinase from Vibrio cholerae O395

International Nuclear Information System (INIS)

Paul, Rakhi; Nath, Seema; Sen, Udayaditya

2012-01-01

A fructokinase from V. cholerae O395 has been cloned, expressed, purified and crystallized in the apo form; the crystals belonged to the orthorhombic space group P2 1 2 1 2 and diffracted to 2.45 Å resolution. Fructokinase with ADP and fructose bound has also been crystallized and the crystals diffracted to a resolution of 1.75 Å. Fructokinase (FK), one of the crucial enzymes for sugar metabolism in bacterial systems, catalyses the unidirectional phosphorylation reaction from fructose to fructose 6-phosphate, thereby allowing parallel entry of fructose into glycolysis beside glucose. The cscK gene from Vibrio cholerae O395 coding for the enzyme FK has been cloned, overexpressed in Escherichia coli BL21 (DE3) and purified using Ni–NTA affinity chromatography. Crystals of V. cholerae FK (Vc-FK) and its cocrystal with fructose, adenosine diphosphate (ADP) and Mg 2+ were grown in the presence of polyethylene glycol 6000 and diffracted to 2.45 and 1.75 Å resolution, respectively. Analysis of the diffraction data showed that both crystal forms have symmetry consistent with space group P2 1 2 1 2, but with different unit-cell parameters. Assuming the presence of two molecules in the asymmetric unit, the Matthews coefficient for the apo Vc-FK crystals was estimated to be 2.4 Å 3 Da −1 , which corresponds to a solvent content of 48%. The corresponding values for the ADP- and sugar-bound Vc-FK crystals were 2.1 Å 3 Da −1 and 40%, respectively, assuming the presence of one molecule in the asymmetric unit

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

OpenAIRE

Yan Boucher

2016-01-01

ABSTRACT 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 coun...

Two-step processing for activation of the cytolysin/hemolysin of Vibrio cholerae O1 biotype El Tor: nucleotide sequence of the structural gene (hlyA) and characterization of the processed products.

Science.gov (United States)

Yamamoto, K; Ichinose, Y; Shinagawa, H; Makino, K; Nakata, A; Iwanaga, M; Honda, T; Miwatani, T

1990-12-01

Vibrio cholerae O1 biotype El Tor produces and secretes a 65-kDa cytolysin/hemolysin into the culture medium. We cloned the structural gene (hlyA) for the cytolysin from the total DNA of a V. cholerae O1 El Tor strain, N86. Nucleotide sequence analysis of hlyA revealed an open reading frame consisting of 2,223 bp which can code for a protein of 741 amino acids with a molecular weight of 81,961. Consistent with this, a 79-kDa protein was identified as the product of hlyA by maxicell analysis in Escherichia coli. N-terminal amino acids of this 79-kDa HlyA protein and those of a 65-kDa El Tor cytolysin purified from V. cholerae were Asn-26 and Asn-158, respectively. The 82- and 79-kDa precursors of the 65-kDa mature cytolysin were found in V. cholerae by pulse-chase labeling and Western blot (immunoblot) analysis of hlyA products. Hemolytic activity of the 79-kDa HlyA protein from E. coli was less than 5% that for the 65-kDa cytolysin from V. cholerae. Our results suggest that in V. cholerae, the 82-kDa preprotoxin synthesized in the cytoplasm is secreted through the membranes into the culture medium as the 79-kDa inactive protoxin after cleavage of the signal peptide and is then further processed into the 65-kDa active cytolysin by release of the N-terminal 15-kDa fragment.

IncA/C plasmids conferring high azithromycin resistance in vibrio cholerae.

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Wang, Ruibai; Liu, Haican; Zhao, Xiuqin; Li, Jie; Wan, Kanglin

2018-01-01

Azithromycin (AZM) is a clinically important antibiotic against Vibrio cholerae, especially for inhibiting V. cholerae colonisation of the intestine and for the treatment of severe cholera in children and pregnant women. An IncA/C plasmid was isolated from two high minimum inhibitory concentration (MIC) AZM-resistant V. cholerae strains of the two mainly pathogenic serogroups (O1 and O139) isolated in China. In the 172 predicted open reading frames (ORFs), 16 genes were related to antibiotic resistance, of which 5 were well-defined genes associated with macrolide resistance. The five macrolide resistance genes distributed in two clusters, mphR-mrx-mph(K) and mel-mph2, flanked by insertion sequence elements and involving two kinds of resistance mechanism. Deletion of the complete region of the two clusters deceased the AZM MIC from ≥64 µg/mL to ≤0.5 µg/mL. This IncA/C plasmid shows great ability to accumulate antibiotic resistance genes. In addition to 11 resistance genes to other antibiotics, 5 macrolide resistance genes with different function were gathered repeatedly through transposition on one plasmid. This genotype could not be simply explained by antibiotic stress applied on the host from the environment or treatment. These phosphorylases and transmembrane transporters might be involved in the transport and metabolism of other non-antibiotic substances, enabling this kind of plasmid to propagate better in the host. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Cell envelope proteins of environmental Vibrio cholerae non O1 isolates from Albufera Lake (Valencia, Spain) influence of some factors on OMP expression.

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Amaro, C; Herrero, E; Arnau, A; Garay, E

1989-11-01

The cell envelope proteins of 89 environmental Vibrio cholerae non O1 strains isolated from lake and coastal waters near Valencia, Spain, and six Vibrio cholerae strains from culture collections were analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Considerable heterogeneity was found in the major proteins of the environmental non-O1 strains, but bands between 25,000 and 48,000 daltons were observed in the majority of the strains. Estimated relative mobilities of the total protein profile ranged between 11 and more than 100 Kd. Cluster analysis revealed four groups of strains distinguishable by presence or absence of high and low molecular weight proteins. After treatment with Sarkosyl, the outer membrane proteins (OMPs) were characterized in all strains by densitometric methods. They ranged from 19 to 87 Kilodaltons, and corresponded to the major proteins observed in the total membrane preparations. The major OMP most frequently found had a molecular weight around 37 Kd, similar to that of porins in other Gram-negative bacteria. The OMP composition varied in response to culture medium and growth phase. Generally the OMP expression was affected only in a quantitative way by the growth phase while the growth medium had both a qualitative and a quantitative effect.

Pandemics, pathogenicity and changing molecular epidemiology of cholera in the era of global warming.

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Chowdhury, Fazle Rabbi; Nur, Zannatun; Hassan, Nazia; von Seidlein, Lorenz; Dunachie, Susanna

2017-03-07

Vibrio cholerae, a Gram-negative, non-spore forming curved rod is found in diverse aquatic ecosystems around the planet. It is classified according to its major surface antigen into around 206 serogroups, of which O1 and O139 cause epidemic cholera. A recent spatial modelling technique estimated that around 2.86 million cholera cases occur globally every year, and of them approximately 95,000 die. About 1.3 billion people are currently at risk of infection from cholera. Meta-analysis and mathematical modelling have demonstrated that due to global warming the burden of vector-borne diseases like malaria, leishmaniasis, meningococcal meningitis, viral encephalitis, dengue and chikungunya will increase in the coming years in the tropics and beyond. This review offers an overview of the interplay between global warming and the pathogenicity and epidemiology of V. cholerae. Several distinctive features of cholera survival (optimal thriving at 15% salinity, 30 °C water temperature, and pH 8.5) indicate a possible role of climate change in triggering the epidemic process. Genetic exchange (ctxAB, zot, ace, cep, and orfU) between strains and transduction process allows potential emergence of new toxigenic clones. These processes are probably controlled by precise environmental signals such as optimum temperature, sunlight and osmotic conditions. Environmental influences on phytoplankton growth and chitin remineralization will be discussed alongside the interplay of poor sanitary conditions, overcrowding, improper sewage disposal and global warming in promoting the growth and transmission of this deadly disease. The development of an effective early warning system based on climate data could help to prevent and control future outbreaks. It may become possible to integrate real-time monitoring of oceanic regions, climate variability and epidemiological and demographic population dynamics to predict cholera outbreaks and support the design of cost-effective public health

Studies on a novel serine protease of a ΔhapAΔprtV Vibrio cholerae O1 strain and its role in hemorrhagic response in the rabbit ileal loop model.

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Aurelia Syngkon

Full Text Available BACKGROUND: Two well-characterized proteases secreted by Vibrio cholerae O1 strains are hemagglutinin protease (HAP and V. cholerae protease (PrtV. The hapA and prtV knock out mutant, V. cholerae O1 strain CHA6.8ΔprtV, still retains residual protease activity. We initiated this study to characterize the protease present in CHA6.8ΔprtV strain and study its role in pathogenesis in rabbit ileal loop model (RIL. METHODOLOGY/PRINCIPAL FINDINGS: We partially purified the residual protease secreted by strain CHA6.8ΔprtV from culture supernatant by anion-exchange chromatography. The major protein band in native PAGE was identified by MS peptide mapping and sequence analysis showed homology with a 59-kDa trypsin-like serine protease encoded by VC1649. The protease activity was partially inhibited by 25 mM PMSF and 10 mM EDTA and completely inhibited by EDTA and PMSF together. RIL assay with culture supernatants of strains C6709 (FA ratio 1.1+/-0.3 n = 3, CHA6.8 (FA ratio 1.08+/-0.2 n = 3, CHA6.8ΔprtV (FA ratio 1.02+/-0.2 n = 3 and partially purified serine protease from CHA6.8ΔprtV (FA ratio 1.2+/-0.3 n = 3 induced fluid accumulation and histopathological studies on rabbit ileum showed destruction of the villus structure with hemorrhage in all layers of the mucosa. RIL assay with culture supernatant of CHA6.8ΔprtVΔVC1649 strain (FA ratio 0.11+/-0.005 n = 3 and with protease incubated with PMSF and EDTA (FA ratio 0.3+/-0.05 n = 3 induced a significantly reduced FA ratio with almost complete normal villus structure. CONCLUSION: Our results show the presence of a novel 59-kDa serine protease in a ΔhapAΔprtV V. cholerae O1 strain and its role in hemorrhagic response in RIL model.

Development of stable Vibrio cholerae O1 Hikojima type vaccine strains co-expressing the Inaba and Ogawa lipopolysaccharide antigens.

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Stefan L Karlsson

Full Text Available We describe here the development of stable classical and El Tor V. cholerae O1 strains of the Hikojima serotype that co-express the Inaba and Ogawa antigens of O1 lipopolysaccharide (LPS. Mutation of the wbeT gene reduced LPS perosamine methylation and thereby gave only partial transformation into Ogawa LPS on the cell surface. The strains express approximately equal amounts of Inaba- and Ogawa-LPS antigens which are preserved after formalin-inactivation of the bacteria. Oral immunizations of both inbred and outbred mice with formalin-inactivated whole-cell vaccine preparations of these strains elicited strong intestinal IgA anti-LPS as well as serum vibriocidal antibody responses against both Inaba and Ogawa that were fully comparable to the responses induced by the licensed Dukoral vaccine. Passive protection studies in infant mice showed that immune sera raised against either of the novel Hikojima vaccine strains protected baby mice against infection with virulent strains of both serotypes. This study illustrates the power of using genetic manipulation to improve the properties of bacteria strains for use in killed whole-cell vaccines.

A Differential Effect of Indian Ocean Dipole and El Niño on Cholera Dynamics in Bangladesh

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Hashizume, Masahiro; Chaves, Luis Fernando; Faruque, A. S. G.; Yunus, Md; Streatfield, Kim; Moji, Kazuhiko

2013-01-01

Background A stationary (i.e., constant through time) association between El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and epidemics of cholera in Bangladesh has been widely assumed. However, whether or not elements of the local climate that are relevant for cholera transmission have stationary signatures of the IOD on their dynamics over different time scales is still not clear. Here we report results on the time-varying relationships between the various remote and local environmental drivers and cholera incidence in Bangladesh. Methodology/Principal Findings We performed a cross wavelet coherency analysis to examine patterns of association between monthly cholera cases in the hospitals in Dhaka and Matlab (1983–2008) and indices for both IOD and ENSO. Our results showed that the strength of both the IOD and ENSO associations with cholera hospitalizations changed across time scales during the study period. In Dhaka, 4-year long coherent cycles were observed between cholera and the index of IOD in 1988–1997. In Matlab, the effect of ENSO was more dominant while there was no evidence for an IOD effect on cholera hospitalizations. Conclusions/Significance Our results call for the consideration of non-stationary, possibly non-linear, patterns of association between cholera hospitalizations and climatic factors in cholera epidemic early warning systems. PMID:23555861

Structural characterization of the extracellular polysaccharide from Vibrio cholerae O1 El-Tor.

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Fitnat Yildiz

Full Text Available The ability to form biofilms is important for environmental survival, transmission, and infectivity of Vibrio cholerae, the causative agent of cholera in humans. To form biofilms, V. cholerae produces an extracellular matrix composed of proteins, nucleic acids and a glycoconjugate, termed Vibrio exopolysaccharide (VPS. Here, we present the data on isolation and characterization of the polysaccharide part of the VPS (VPS-PS, which has the following structure: -4-α-GulpNAcAGly3OAc-(1-4-β-D-Glcp-(1-4-α-Glcp-(1-4-α-D-Galp-(1- where α-D-Glc is partially (∼20% replaced with α-D-GlcNAc. α-GulNAcAGly is an amide between 2-acetamido-2-deoxy-α-guluronic acid and glycine. Apparently, the polysaccharide is bound to a yet unidentified component, which gives it high viscosity and completely suppresses any NMR signals belonging to the sugar chains of the VPS. The only reliable method to remove this component at present is a treatment of the whole glycoconjugate with concentrated hydrochloric acid.

139La and 63Cu NMR investigation of charge order in La2CuO4 +y (Tc=42 K)

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Imai, T.; Lee, Y. S.

2018-03-01

We report 139La and 63Cu NMR investigation of the successive charge order, spin order, and superconducting transitions in superoxygenated La2CuO4 +y single crystal with stage-4 excess oxygen order at Tstage≃290 K. We show that the stage-4 order induces tilting of CuO6 octahedra below Tstage, which in turn causes 139La NMR line broadening. The structural distortion continues to develop far below Tstage, and completes at Tcharge≃60 K, where charge order sets in. This sequence is reminiscent of the the charge-order transition in Nd codoped La1.88Sr0.12CuO4 that sets in once the low-temperature tetragonal phase is established. We also show that the paramagnetic 63Cu NMR signals are progressively wiped out below Tcharge due to enhanced low-frequency spin fluctuations in charge-ordered domains, but the residual 63Cu NMR signals continue to exhibit the characteristics expected for optimally doped superconducting CuO2 planes. This indicates that charge order in La2CuO4 +y does not take place uniformly in space. In addition, unlike the typical second-order magnetic phase transitions, low-frequency Cu spin fluctuations as probed by 139La nuclear spin-lattice relaxation rate do not exhibit critical divergence at Tspin(≃Tc ) =42 K. These findings, including the spatially inhomogeneous nature of the charge-ordered state, are qualitatively similar to the case of La1.885Sr0.115CuO4 [Imai et al., Phys. Rev. B 96, 224508 (2017), 10.1103/PhysRevB.96.224508 and Arsenault et al., Phys. Rev. B 97, 064511 (2018), 10.1103/PhysRevB.97.064511], but both charge and spin order take place more sharply in the present case.

Modulating the Global Response Regulator, LuxO of V. cholerae Quorum Sensing System Using a Pyrazine Dicarboxylic Acid Derivative (PDCApy: An Antivirulence Approach

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M. Hema

2017-10-01

Full Text Available Vibrio cholerae is a Gram-negative pathogen which causes acute diarrhoeal disease, cholera by the expression of virulence genes through quorum sensing (QS mechanism. The QS circuit of V. cholerae is controlled by the global quorum regulator, LuxO, which at low cell density (LCD state produces major virulence factors such as, toxin co-regulated pilus (TCP and cholera toxin (CT to mediate infection. On the contrary, at the high cell density (HCD state the virulent genes are downregulated and the vibrios are detached from the host intestinal epithelial cells, promoted by HapA protease. Hence, targeting the global regulator LuxO would be a promising approach to modulate the QS to curtail V. cholerae pathogenesis. In our earlier studies, LuxO targeted ligand, 2,3 pyrazine dicarboxylic acid (PDCA and its derivatives having desired pharmacophore properties were chemically synthesized and were shown to have biofilm inhibition as well as synergistic activity with the conventionally used antibiotics. In the present study, the QS modulatory effect of the PDCA derivative with pyrrolidine moiety designated as PDCApy against the V. cholerae virulence gene expression was analyzed at various growth phases. The data significantly showed a several fold reduction in the expression of the genes, tcp and ct whereas the expression of hapR was upregulated at the LCD state. In addition, PDCApy reduced the adhesion and invasion of the vibrios onto the INT407 intestinal cell lines. Collectively, our data suggest that PDCApy could be a potential QS modulator (QSM for the antivirulence therapeutic approach.

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African Journals Online (AJOL)

UDSM

In this study, the occurrence of culturable Vibrio cholerae serogroup O1 and O139 in three selected Tanzanian Estuaries ... INTRODUCTION. Cholera is a waterborne infectious disease ..... Brazil, Peru, Chile, Mexico, India and. United States of ...

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

OpenAIRE

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-01-01

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ.

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

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Kambang Sariadji

2013-05-01

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

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013.

Science.gov (United States)

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-10-30

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. Copyright © 2014 Díaz-Quiñonez et al.

Two forms of Vibrio cholerae O1 El Tor hemolysin derived from identical precursor protein.

Science.gov (United States)

Ikigai, H; Ono, T; Nakae, T; Otsuru, H; Shimamura, T

1999-01-08

Vibrio cholerae O1 grown in heart infusion broth produces two forms of El Tor hemolysin (ETH) monomers of 65 and 50 kDa. These monomers form several different sizes of mixed oligomers ranging from 180 to 280 kDa in the liposomal membranes. We found that the N-terminal amino acid sequences, NH2-Trp-Pro-Ala-Pro-Ala-Asn-Ser-Glu, of both the 65- and 50-kDa toxins were identical. We assumed, therefore, that the 65- and 50-kDa toxins were derivatives of the identical precursor protein and the 50-kDa protein was a truncated derivative of 65-kDa ETH. To substantiate this assumption, we treated the 260-kDa oligomer with trypsin and obtained a 190-kDa oligomer. This 190-kDa oligomer consisted of only the 50-kDa subunits. Both 260- and 190-kDa oligomers formed ion channels indistinguishable from each other in planar lipid bilayers. These results suggest that the essential part of the ETH in forming the membrane-damaging aggregate is a 50-kDa protein.

Complicações pós-operatórias em 139 casos de impressão basilar e/ou malformação de Arnold-Chiari

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José Alberto Gonçalves da Silva

1981-09-01

Full Text Available No presente trabalho, foram analisadas as complicações pós-operatórias observadas em 139 casos de impressão basilar e/ou malformação de Arnold-Chiari. Os autores chamam a atenção para a menor ocorrência de complicações e de mortalidade verificadas nos pacientes que foram submetidos à plástica da dura-mater da fossa posterior.

Evaluation of Cholera Toxin Expression in Acidic, Alkaline and Neutral Conditions

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Narges Rahimi

2015-02-01

Full Text Available Background: Cholera is a severe disease which is caused by Vibrio cholerae and it is typically transmitted by either contaminated food or water particularly in developing countries. The most important virulence factor of this bacterium is an enterotoxin called cholera toxin which is a protein complex secreted by the Vibrio cholerae. Objectives: In this project, we determined the production of cholera toxin at different pH values. Materials and Methods: Two standard strain of Vibrio cholerae O1 biovar EL Tor N16961 and Vibrio cholerae O1 biovar Classic ATCC 14035 were used. After overnight cultivation of both the strains the total mRNA extracted and converted to total cDNA. Results: By Relative Real-Time PCR analysis the most cholera toxin production in classical and El Tor strains was at pH 8.5 and 8, respectively. Conclusions: Therefore, We may conclude that use of acidic diet will help in reduction of cholera toxin production.

Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

Science.gov (United States)

Islam, M Sirajul; Islam, M Shafiqul; Mahmud, Zahid H; Cairncross, Sandy; Clemens, John D; Collins, Andrew E

2015-09-01

In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

NCBI nr-aa BLAST: CBRC-CFAM-16-0042 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-CFAM-16-0042 gb|AAC46251.1| putative epimerase/dehydratase [Vibrio cholerae O1...39] dbj|BAA33614.1| unknown [Vibrio cholerae] gb|EAZ47467.1| UDP-D-quinovosamine 4-dehydrogenase [Vibrio cholerae MO10] AAC46251.1 0.46 27% ...

Vaxchora: A Single-Dose Oral Cholera Vaccine.

Science.gov (United States)

Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

2017-07-01

To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

Cholera: an overview with reference to the Yemen epidemic.

Science.gov (United States)

Rabaan, Ali A

2018-06-22

Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

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

Science.gov (United States)

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

2011-01-01

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

Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

International Nuclear Information System (INIS)

Sharma, Anshu; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B; Baral, Dinesh

2015-01-01

We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe 3 O 4 )) 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 Fe 3 O 4 and CA-Fe 3 O 4 /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 Fe 3 O 4 , CA-Fe 3 O 4 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 (Fe 3 O 4 ) and 189.51 nm (CA-Fe 3 O 4 ) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe 2 O 3 /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. (paper)

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......, all originating from shrimp produced in aquaculture. Six isolated strains agglutinated in polyvalent O antisera, but did not agglutinate in Ogawa or Inaba antisera. The six strains were resistant to colistin and sulfisoxazole; three strains also showed resistance to ampicillin. None of the strains...... 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....

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

African Journals Online (AJOL)

2013-08-20

Aug 20, 2013 ... mental water samples, as well as for confirmation of clinical isolates. Keywords: ... Monitoring the presence of V. cholerae in drinking water sources ... have several advantages: they are rapid, sensitive, highly selective and do ...

Clinical isolates of Vibrio cholerae O1 El Tor Ogawa of 2009 from Kolkata, India: preponderance of SXT element and presence of Haitian ctxB variant.

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Braj M R N S Kutar

Full Text Available BACKGROUND: Increase in the number of multidrug resistant pathogens and the accompanied rise in case fatality rates has hampered the treatment of many infectious diseases including cholera. Unraveling the mechanisms responsible for multidrug resistance in the clinical isolates of Vibrio cholerae would help in understanding evolution of these pathogenic bacteria and their epidemic potential. This study was carried out to identify genetic factors responsible for multiple drug resistance in clinical isolates of Vibrio cholerae O1, serotype Ogawa, biotype El Tor isolated from the patients admitted to the Infectious Diseases Hospital, Kolkata, India, in 2009. METHODOLOGY/PRINCIPAL FINDINGS: One hundred and nineteen clinical isolates of V. cholerae were analysed for their antibiotic resistance phenotypes. Antibiogram analysis revealed that majority of the isolates showed resistance to co-trimoxazole, nalidixic acid, polymixin B and streptomycin. In PCR, SXT integrase was detected in 117 isolates and its sequence showed 99% identity notably to ICEVchInd5 from Sevagram, India, ICEVchBan5 from Bangladesh and VC1786ICE sequence from Haiti outbreak among others. Antibiotic resistance traits corresponding to SXT element were transferred from the parent Vibrio isolate to the recipient E. coli XL-1 Blue cells during conjugation. Double-mismatch-amplification mutation assay (DMAMA revealed the presence of Haitian type ctxB allele of genotype 7 in 55 isolates and the classical ctxB allele of genotype 1 in 59 isolates. Analysis of topoisomerase sequences revealed the presence of mutation Ser83 → Ile in gyrA and Ser85→ Leu in parC. This clearly showed the circulation of SXT-containing V. cholerae as causative agent for cholera in Kolkata. CONCLUSIONS: There was predominance of SXT element in these clinical isolates from Kolkata region which also accounted for their antibiotic resistance phenotype typical of this element. DMAMA PCR showed them to be a mixture

A arte de curar dos profissionais de saúde popular em tempo de cólera: Grão-Pará do século XIX The curative art of specialists in folk medicine in times of cholera: 19th century Grão-Pará

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Jane Felipe Beltrão

2000-09-01

Full Text Available Durante a epidemia de cólera que assolou o Grão-Pará, em 1855, pouco mais de uma dezena de anônimos profissionais de saúde popular inscreveram suas artes de curar nos anais da história. As terapias não eram muitas, mas foram disseminadas nos jornais provinciais ou pela forte tradição oral presente na Amazônia. Uma dessas terapias - o uso do sumo de limão - chegou a ser avalizada pelos médicos da província como cientificamente correta. Os homens que "não eram médicos, nem cirurgiões" usavam ervas e frutos medicinais preparados em sumos, infusões, banhos, emplastos e supositórios, rompendo as fronteiras estabelecidas pela arte oficial de curar, a medicina alopática, que tentava estabelecer-se hegemonicamente. Descrevo a trilha da cólera até o Grão-Pará e analiso o contexto social da epidemia; os conhecimentos sobre a cólera: as possibilidades de socorro oferecidas à população e as práticas curativas então adotadas.During the cholera epidemics that affected the Grão-Pará Province in 1855, not more than ten anonymous public health professionals registered in history their curing powers as they relieved cholera victims. There were not too many therapies, but they were publicized in letters printed in local newspapers. The therapeutical powers of alternative medicine was disseminated throughout the Amazon thanks to the strong oral history tradition. One of such therapies - the usage of lemon juice - was adopted by medical doctors in the Province and later on scientifically accredited. Citizens who "were not doctors, nor surgeons" used medicinal herbs and fruits to prepare juices, infusions, baths, plasters and suppositories. They went over the limits established by the official medicine, allopathy, which acted hegemonically. The article describes the path that cholera traveled to reach Grão-Pará and the ensuing scourge of Belém. Data are presented on mortality, the social context of the event, health-care knowledge

Características de la epidemia de cólera de 1998 en Ecuador, durante el fenómeno de "El Niño" Characteristics of the cholera epidemic of 1998 in Ecuador during El Niño

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Jean-Marc Gabastou

2002-09-01

Full Text Available Objetivos. Caracterizar el brote de cólera ocurrido en Ecuador en 1998 durante el fenómeno de "El Niño", presentar los datos sobre la resistencia de las cepas circulantes de Vibrio cholerae a los antimicrobianos y describir las medidas preventivas tomadas por las autoridades sanitarias para reducir el impacto de la enfermedad. Métodos. Los datos epidemiológicos provienen de los registros de la Dirección Nacional de Epidemiología del Ministerio de Salud Pública de Ecuador y del Instituto Nacional de Higiene y Medicina Tropical, y el informe final del Programa de Formación para la Lucha contra el Cólera y las Enfermedades Diarreicas (PROCED ALA 93/25. Se procedió a aislar, identificar y serotipificar V. cholerae en las muestras de heces de 10% de los pacientes con posible cólera identificados entre el 1 de enero y el 31 de diciembre de 1998. Los casos sospechados se definieron por la aparición súbita de diarrea acuosa, con o sin deshidratación, en zonas epidémicas. Las cepas aisladas se sometieron a un antibiograma estándar por el método de difusión, en el que se probaron los siguientes antibióticos: amoxicilina, tetraciclina, sulfametoxazol con trimetoprim, compuesto vibriostático O/129, ácido nalidíxico, eritromicina, norfloxacino, ciprofloxacino, gentamicina, cloranfenicol y colistina. Resultados. En 1998 se notificaron 3 755 casos en 17 de las 21 provincias del país, lo que corresponde a una tasa de incidencia de 53,96 por 100 000 habitantes. Treinta y siete pacientes fallecieron, lo cual supone una tasa de letalidad del 0,97%. Se aislaron 301 cepas de V. cholerae en las 637 muestras con sospechosa de cólera que se procesaron; todas correspondieron a V. cholerae O:1, El Tor, subtipo Ogawa. La totalidad de las cepas fueron sensibles a la tetraciclina y a las quinolonas, y 5,6% resistentes a la eritromicina. La única cepa resistente a la amoxicilina fue multirresistente. Las autoridades nacionales pusieron en pr

Report of the Working Group on Strengthening the Biosecurity of the United States

Science.gov (United States)

2009-10-01

Typhi (Typhoid) 9 Vibrio cholerae ( Cholera ) (serotypes O1 and O139 only) 10 Yellow fever virus (non-vaccine strains) APPENDIX 4-A 123 Appendix 4-A...is unknown. Scientists at Los Alamos National Laboratory in New Mexico determined the spores were derived from least four different strains of B

Cholera after the consumption of raw oysters. A case report.

Science.gov (United States)

Klontz, K C; Tauxe, R V; Cook, W L; Riley, W H; Wachsmuth, I K

1987-12-01

In August 1986, a 76-year-old woman in Miami, Florida, developed profuse watery diarrhea and abdominal cramps. Two and four days before the onset of her illness, she had eaten six raw oysters at each of two restaurants in Miami. A stool specimen yielded toxigenic Vibrio cholerae O1 biotype El Tor, serotype Inaba. The results of toxin gene probing of the organism recovered from the patient differed significantly from those of other V. cholerae O1 isolates from the Gulf Coast and elsewhere in the world. A program of active surveillance identified no other cases of cholera in Miami. The source of the raw oysters eaten by the patient was traced to Louisiana. Her case represents the first reported case of cholera associated with eating raw oysters.

[Synthesis of protective antigens during submerged cultivation of Vibrio cholerae].

Science.gov (United States)

Fedorova, V A; Syrova, N A; Gromova, O V; Tershkina, N E; Devdariani, Z L; Dzhaparidze, M N; Meleshchenko, M V; Dobrova, G V; Beliakova, N I; Ermakov, N M; Eliseev, Iu Iu

2000-01-01

The effectiveness of dot immunoanalysis for evaluating the dynamics of the synthesis of O-antigen, cholera toxin, neuraminidase, adhesin CFA1 in the process of the reactor cultivation of V. cholerae used for the production of oral chemical cholera vaccine is shown. The established regularities of the synthesis of the protective antigens of V. cholerae in the process of scaled-up cultivation are discussed.

Prevalence of Vibrio cholerae O1 serogroup in Assam, India: A hospital-based study

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Ajanta Sharma

2017-01-01

Interpretation & conclusions: Emergence of resistance amongst V. cholerae towards many antibiotics is a matter of concern. Hence, continuous surveillance for diarrhoeal disorders is necessary to control the future outbreaks of cholera in this region.

Comparison and Evaluation of the Molecular Typing Methods for Toxigenic Vibrio cholerae in Southwest China.

Science.gov (United States)

Liao, Feng; Mo, Zhishuo; Chen, Meiling; Pang, Bo; Fu, Xiaoqing; Xu, Wen; Jing, Huaiqi; Kan, Biao; Gu, Wenpeng

2018-01-01

Vibrio cholerae O1 strains taken from the repository of Yunnan province, southwest China, were abundant and special. We selected 70 typical toxigenic V. cholerae (69 O1 and one O139 serogroup strains) isolated from Yunnan province, performed the pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and MLST of virulence gene (V-MLST) methods, and evaluated the resolution abilities for typing methods. The ctxB subunit sequence analysis for all strains have shown that cholera between 1986 and 1995 was associated with mixed infections with El Tor and El Tor variants, while infections after 1996 were all caused by El Tor variant strains. Seventy V. cholerae obtained 50 PFGE patterns, with a high resolution. The strains could be divided into three groups with predominance of strains isolated during 1980s, 1990s, and 2000s, respectively, showing a good consistency with the epidemiological investigation. We also evaluated two MLST method for V. cholerae , one was used seven housekeeping genes ( adk , gyrB , metE , pntA , mdh , purM , and pyrC ), and all the isolates belonged to ST69; another was used nine housekeeping genes ( cat , chi , dnaE , gyrB , lap , pgm , recA , rstA , and gmd ). A total of seven sequence types (STs) were found by using this method for all the strains; among them, rstA gene had five alleles, recA and gmd have two alleles, and others had only one allele. The virulence gene sequence typing method ( ctxAB , tcpA , and toxR ) showed that 70 strains were divided into nine STs; among them, tcpA gene had six alleles, toxR had five alleles, while ctxAB was identical for all the strains. The latter two sequences based typing methods also had consistency with epidemiology of the strains. PFGE had a higher resolution ability compared with the sequence based typing method, and MLST used seven housekeeping genes showed the lower resolution power than nine housekeeping genes and virulence genes methods. These two sequence typing methods

Comparison and Evaluation of the Molecular Typing Methods for Toxigenic Vibrio cholerae in Southwest China

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Feng Liao

2018-05-01

Full Text Available Vibrio cholerae O1 strains taken from the repository of Yunnan province, southwest China, were abundant and special. We selected 70 typical toxigenic V. cholerae (69 O1 and one O139 serogroup strains isolated from Yunnan province, performed the pulsed field gel electrophoresis (PFGE, multilocus sequence typing (MLST, and MLST of virulence gene (V-MLST methods, and evaluated the resolution abilities for typing methods. The ctxB subunit sequence analysis for all strains have shown that cholera between 1986 and 1995 was associated with mixed infections with El Tor and El Tor variants, while infections after 1996 were all caused by El Tor variant strains. Seventy V. cholerae obtained 50 PFGE patterns, with a high resolution. The strains could be divided into three groups with predominance of strains isolated during 1980s, 1990s, and 2000s, respectively, showing a good consistency with the epidemiological investigation. We also evaluated two MLST method for V. cholerae, one was used seven housekeeping genes (adk, gyrB, metE, pntA, mdh, purM, and pyrC, and all the isolates belonged to ST69; another was used nine housekeeping genes (cat, chi, dnaE, gyrB, lap, pgm, recA, rstA, and gmd. A total of seven sequence types (STs were found by using this method for all the strains; among them, rstA gene had five alleles, recA and gmd have two alleles, and others had only one allele. The virulence gene sequence typing method (ctxAB, tcpA, and toxR showed that 70 strains were divided into nine STs; among them, tcpA gene had six alleles, toxR had five alleles, while ctxAB was identical for all the strains. The latter two sequences based typing methods also had consistency with epidemiology of the strains. PFGE had a higher resolution ability compared with the sequence based typing method, and MLST used seven housekeeping genes showed the lower resolution power than nine housekeeping genes and virulence genes methods. These two sequence typing methods could

An outbreak of cholera in Medipally village, Andhra Pradesh, India, 2013.

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Uthappa, Chengappa K; Allam, Ramesh R; Nalini, Chava; Gunti, Deepak; Udaragudi, Prasada R; Tadi, Geetha P; Murhekar, Manoj V

2015-07-24

Cholera continues to remain endemic in over 50 countries and has caused large epidemics with around 3-5 million cases occurring every year in Asia alone. In India, cholera is endemic in many states. However, etiological information and age-specific incidence related to cholera outbreaks is limited. In November 2013, district authorities reported a cluster of diarrheal disease among residents of Medipally to the state surveillance unit. We investigated this cluster to confirm its etiology, describe its magnitude, identify potential risk factors, and make recommendations for control. A house-to-house active search was conducted to identify cases of acute diarrhea and collect information on drinking water source. Drinking water samples were collected from common water sources and sampled households to test for bacteriological quality. Ten stool samples were collected for culture. A matched case-control study was conducted to identify the risk factors. A total of 138 case-patients of diarrhea (Attack rate: 11.5/100; 15 1,200) and 1 death (Case Fatality Ratio: 0.72/100) were identified. Five of the 10 stool samples were culture positive for V. cholerae, serogroup O1 El Tor. Drinking water from the overhead tank [Adjusted OR (AOR): 31.94, 95% CI: 7.3-139.5] was associated with risk of developing illness. This outbreak affected nearly 11% of the village population and was due to contamination of the main drinking water source. Outbreaks such as this can be prevented by constructing the drain away from the water pipelines and by monitoring regular chlorination of drinking water source and inspection of pipelines for damage.

In situ measured elimination of Vibrio cholerae from brackish water.

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Pérez, María Elena Martínez; Macek, Miroslav; Galván, María Teresa Castro

2004-01-01

In situ elimination of fluorescently labelled Vibrio cholerae (FLB) was measured in two saline water bodies in Mexico: in a brackish water lagoon, Mecoacán (Gulf of Mexico; State of Tabasco) and an athalassohaline lake, Alchichica (State of Puebla). Disappearance rates of fluorescently labelled V. cholera O1 showed that they were eliminated from the environment at an average rate of 32% and 63%/day, respectively (based on the bacterial standing stocks). The indirect immunofluorescence method confirmed the presence of V. cholerae O1 in the lagoon. However, the elimination of FLB was not directly related either to the presence or absence of the bacterium in the water body or to the phytoplankton concentration.

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

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John Kiiru

Full Text Available Cholera remains a significant public health challenge in many sub-Saharan countries including Kenya. We have performed a combination of phylogenetic and phenotypic analysis based on whole genome DNA sequences derived from 40 environmental and 57 clinical V. cholerae from different regions of Kenya isolated between 2005 and 2010. Some environmental and all clinical isolates mapped back onto wave three of the monophyletic seventh pandemic V. cholerae El Tor phylogeny but other environmental isolates were phylogenetically very distinct. Thus, the genomes of the Kenyan V. cholerae O1 El Tor isolates are clonally related to other El Tor V. cholerae isolated elsewhere in the world and similarly harbour antibiotic resistance-associated STX elements. Further, the Kenyan O1 El Tor isolates fall into two distinct clades that may have entered Kenya independently.

Single-layer TiO x reconstructions on SrTiO₃ (111): (√7 × √7)R19.1°, (√13 × √13)R13.9°, and related structures

Energy Technology Data Exchange (ETDEWEB)

Andersen, Tassie K.; Wang, Shuqiu; Castell, Martin R.; Fong, Dillon D.; Marks, Laurence D.

2018-09-01

The atomic structures of two reconstructions, (√7 × √7)R19.1° and (√13 × √13)R13.9°, on the SrTiO₃ (111) surface were determined using a combination of density functional theory and scanning tunneling microscopy data and simulations. The combination of these methods allows for potential surface structures to be generated and verified in the absence of diffraction data, providing another tool for solving surface reconstructions. These reconstructions belong to the same stoichiometric, nSrTiO₃ • mTiO₂, structural family made up of an interconnected, single layer of edge-sharing TiO₆ and TiO₅[] octahedra. This family is found to include the previously-solved (2 × 2)a reconstruction as its smallest unit-cell sized member and serves as a tool for better understanding and predicting the structure of other reconstructions of arbitrary surface unit-cell size on SrTiO₃ (111). This reconstruction family and the calculations of surface energies for different hypothesis structures also shed light on the structure of Schottky defects observed on these reconstructed SrTO₃ (111) surfaces.

Emergência da múltipla resistência a antimicrobianos em Vibrio cholerae isolados de pacientes com gastroenterite no Ceará, Brasil

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Hofer Ernesto

1999-01-01

Full Text Available Das 7058 amostras de Vibrio cholerae isoladas de pacientes com suspeita de síndrome coleriforme, no período de 1991 a 1993, no Estado do Ceará, foram detectadas duas com as características de múltipla resistência aos antimicrobianos (tetraciclina, ampicilina, eritromicina, sulfametoxazol-trimetoprima e ao composto vibriostático O/129 (2,4-diamino-6,7-diisopropilpteridina. Do ponto de vista bacteriológico uma amostra foi identificada como V. cholerae sorogrupo O:1, biotipo El Tor e sorovar Inaba e a outra, caracterizada como V. cholerae sorogrupo O:22, classificada bioquimicamente no tipo II de Heiberg. Foi demonstrado que apenas na amostra do sorogrupo O:1, a multirresistência era codificada por um plasmídio, transferível por conjugação para Escherichia coli K12 e amostras sensíveis de V. cholerae O1 e não O1, numa freqüência entre 8x10-2 a 5x10-6. O plasmídio responsável pela multirresistência apresentou um peso molecular de 147 Kb, compatível com as descrições em outras partes do mundo.

Vibriocidal antibody responses to a bivalent killed whole-cell oral cholera vaccine in a phase III trial in Kolkata, India.

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Suman Kanungo

Full Text Available BACKGROUND: During the development of a vaccine, identification of the correlates of protection is of paramount importance for establishing an objective criterion for the protective performance of the vaccine. However, the ascertainment of correlates of immunity conferred by any vaccine is a difficult task. METHODS: While conducting a phase three double-blind, cluster-randomized, placebo-controlled trial of a bivalent killed whole-cell oral cholera vaccine in Kolkata, we evaluated the immunogenicity of the vaccine in a subset of participants. Randomly chosen participants (recipients of vaccine or placebo were invited to provide blood samples at baseline, 14 days after the second dose and one year after the first dose. At these time points, serum geometric mean titers (GMT of vibriocidal antibodies and seroconversion rates for vaccine and placebo arms were calculated and compared across the age strata (1 to 5 years, 5 to 15 years and more than 15 years as well as for all age groups. RESULTS: Out of 137 subjects included in analysis, 69 were vaccinees and 68 received placebo. There were 5•7 and 5•8 geometric mean fold (GMF rises in titers to Vibrio cholerae Inaba and Ogawa, respectively at 14 days after the second dose, with 57% and 61% of vaccinees showing a four-fold or greater titer rise, respectively. After one year, the titers to Inaba and Ogawa remained 1•7 and 2•8 fold higher, respectively, compared to baseline. Serum vibriocidal antibody response to V. cholerae O139 was much lower than that to Inaba or Ogawa. No significant differences in the GMF-rises were observed among the age groups. CONCLUSIONS: The reformulated oral cholera vaccine induced a statistically significant anti-O1 Inaba and O1 Ogawa vibriocidal antibody response 14 days after vaccination, which although declined after one year remained significantly higher than baseline. Despite this decline, the vaccine remained protective five years after vaccination.

[DETERMINATION OF TYPES OF EPIDEMIC MANIFESTATIONS OF CHOLERA IN REGIONS OF THE CRIMEA FEDERAL DISTRICT (REPUBLIC OF CRIMEA)].

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Onischenko, G G; Popova, A Yu; Moskvitina, E A; Penkovskaya, N A; Listopad, S A; Titova, S V; Kruglikov, V D

2015-01-01

The aim of the study was determination of the type of epidemic manifestations of cholera in the Republic of Crimea based on evaluation of epidemic manifestations of cholera risk of introduction and spread of the infection. It was concluded, that, based on the cholera outbreaks, that had taken place, contamination of surface water bodies (fresh and sea) and sewage by Vibrio cholerae O1 ctxA+ and Vibrio cholerae O1 ctXA- potential epidemic danger of introduction of the infection by various types of international transport, population migration, the presence of epidemiologic risk in realization of water pathway of transmission of cholera causative agent and several other social conditions, the Republic of Crimea remains in the group of territories of type I by epidemic manifestations of cholera.

Household and Individual Risk Factors for Cholera among Cholera Vaccine Recipients in Rural Haiti.

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Matias, Wilfredo R; Teng, Jessica E; Hilaire, Isabelle J; Harris, Jason B; Franke, Molly F; Ivers, Louise C

2017-08-01

Oral cholera vaccination was used as part of cholera control in Haiti, but the vaccine does not provide complete protection. We conducted secondary data analyses of a vaccine effectiveness study in Haiti to evaluate risk factors for cholera among cholera vaccine recipients. Individuals vaccinated against cholera that presented with acute watery diarrhea and had a stool sample positive for Vibrio cholerae O1 were included as cases. Up to four vaccinated individuals who did not present for treatment of diarrhea were included as controls for each case, and matched by location of residence, enrollment time, and age. We evaluated sociodemographic characteristics and risk factors for cholera. Univariable and multivariable logistic regression were performed to identify risk factors for cholera among vaccinees. Thirty-three vaccine recipients with culture-confirmed cholera were included as cases. One-hundred-and-seventeen of their matched controls reported receiving vaccine and were included as controls. In a multivariable analysis, self-reporting use of branded household water disinfection products as a means of treating water (adjusted relative risk [aRR] = 44.3, 95% confidence interval [CI] = 4.19-468.05, P = 0.002), and reporting having a latrine as the main household toilet (aRR = 4.22, 95% CI = 1.23-14.43, P = 0.02), were independent risk factors for cholera. Self-reporting always treating water (aRR = 0.09, 95% CI = 0.01-0.57, P = 0.01) was associated with protection against cholera. The field effectiveness of water, sanitation, and hygiene interventions used in combination with cholera vaccination in cholera control should be measured and monitored over time to identify and remediate shortcomings, and ensure successful impact on disease control.

Vibrio cholerae Classical Biotype Strains Reveal Distinct Signatures in Mexico

OpenAIRE

Alam, Munirul; Islam, M. Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A.; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R.; Cravioto, Alejandro

2012-01-01

Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 199...

Desempeño de los sistemas Cholera-SMART® y Pathogen-Detection-Kit® en el diagnóstico rápido del cólera Performance of Cholera-SMART® and Pathogen-Detection-Kit® in the quick diagnosis of cholera

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Hilda María Bolaños

2004-10-01

Full Text Available OBJETIVOS: Comparar el desempeño de dos sistemas rápidos de diagnóstico de cólera con el método de cultivo y proponer una estrategia que permita mejorar la especificidad y la sensibilidad de estos sistemas y disminuir los costos del diagnóstico. MÉTODOS: En el estudio participaron el Centro Nacional de Referencia en Bacteriología (CNRB del Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA y hospitales de las provincias de Alajuela, Guanacaste y San José, en Costa Rica. Se emplearon 237 muestras de heces para evaluar el desempeño de dos pruebas rápidas para el diagnóstico de Vibrio cholerae O1: Pathogen Detection Kit® (PDK, Intelligent Monitoring Systems, Gainsville, Florida, EUA y Cholera-SMART® (New Horizons Diagnostics Corp., Columbia, Maryland, EUA, tanto en forma directa (SMART directo y PDK directo como a partir de cultivos de enriquecimiento de 6 horas (SMART-6 y PDK-6 y de 18 horas (SMART-18 y PDK-18 a 37 °C en agua de peptona alcalina. Las muestras diarreicas y semiformadas se cultivaron y se evaluaron con las pruebas rápidas directas; cuando el resultado inicial era negativo se repitieron a las 6 y 18 horas de cultivo. Los hisopados rectales y fecales se evaluaron a partir de cultivos de enriquecimiento de 6 y de 18 horas. Adicionalmente se estudió la sensibilidad analítica de los sistemas rápidos con cultivos puros de 18 a 24 horas de incubación de V. cholerae O1 (cepa SOS-833, CNRB, Costa Rica y se evaluó la utilidad del análisis microscópico de la motilidad para racionalizar el uso de las técnicas rápidas. RESULTADOS: La sensibilidad, tanto de SMART directo como de PDK directo, fue de 100% en muestras de heces diarreicas y semiformadas y en contenido intestinal de cadáveres. Con estas muestras, el procedimiento SMART directo mostró una especificidad de 100%, mientras que con el PDK directo esta fue de 85,7% a 77,4%, en dependencia del tipo de muestra. Los resultados

Molecular Epidemiology of Cholera Outbreaks during the Rainy Season in Mandalay, Myanmar.

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Roobthaisong, Amonrattana; Okada, Kazuhisa; Htun, Nilar; Aung, Wah Wah; Wongboot, Warawan; Kamjumphol, Watcharaporn; Han, Aye Aye; Yi, Yi; Hamada, Shigeyuki

2017-11-01

Cholera, caused by Vibrio cholerae , remains a global threat to public health. In Myanmar, the availability of published information on the occurrence of the disease is scarce. We report here that cholera incidence in Mandalay generally exhibited a single annual peak, with an annual average of 312 patients with severe dehydration over the past 5 years (since 2011) and was closely associated with the rainy season. We analyzed cholera outbreaks, characterized 67 isolates of V. cholerae serogroup O1 in 2015 from patients from Mandalay, and compared them with 22 V. cholerae O1 isolates (12 from Mandalay and 10 from Yangon) in 2014. The isolates carried the classical cholera toxin B subunit ( ctxB ), the toxin-coregulated pilus A ( tcpA ) of Haitian type, and repeat sequence transcriptional regulator ( rstR ) of El Tor type. Two molecular typing methods, pulsed-field gel electrophoresis and multiple-locus variable-number tandem repeat analysis (MLVA), differentiated the 89 isolates into seven pulsotypes and 15 MLVA profiles. Pulsotype Y15 and one MLVA profile (11, 7, 7, 16, 7) were predominantly found in the isolates from cholera outbreaks in Mandalay, 2015. Pulsotypes Y11, Y12, and Y15 with some MLVA profiles were detected in the isolates from two remote areas, Mandalay and Yangon, with temporal changes. These data suggested that cholera spread from the seaside to the inland area in Myanmar.

ADP-ribosylation by cholera toxin: functional analysis of a cellular system that stimulates the enzymic activity of cholera toxin fragment A1

International Nuclear Information System (INIS)

Gill, D.M.; Coburn, J.

1987-01-01

The authors have clarified relationships between cholera toxin, cholera toxin substrates, a membrane protein S that is required for toxin activity, and a soluble protein CF that is needed for the function of S. The toxin has little intrinsic ability to catalyze ADP-ribosylations unless it encounters the active form of the S protein, which is S liganded to GTP or to a GTP analogue. In the presence of CF, S x GTP forms readily, though reversibly, but a more permanent active species, S-guanosine 5'-O-(3-thiotriphosphate) (S x GTPγS), forms over a period of 10-15 min at 37 0 C. Both guanosine 5'-O-(2-thiodiphosphate) and GTP block this quasi-permanent activation. Some S x GTPγS forms in membranes that are exposed to CF alone and then to GTPγS, with a wash in between, and it is possible that CF facilitates a G nucleotide exchange. S x GTPγS dissolved by nonionic detergents persists in solution and can be used to support the ADP-ribosylation of nucleotide-free substrates. In this circumstance, added guanyl nucleotides have no further effect. This active form of S is unstable, especially when heated, but the thermal inactivation above 45 0 C is decreased by GTPγS. Active S is required equally for the ADP-ribosylation of all of cholera toxin's protein substrates, regardless of whether they bind GTP or not. They suggest that active S interacts directly with the enzymic A 1 fragments of cholera toxin and not with any toxin substrate. The activation and activity of S are independent of the state, or even the presence, of adenylate cyclase and seem to be involved with the cyclase system only via cholera toxin. S is apparently not related by function to certain other GTP binding proteins, including p21/sup ras/, and appears to be a new GTP binding protein whose physiologic role remains to be identified

Prevalence of Vibrio cholerae in Coastal Alternative Supplies of Drinking Water and Association with Bacillus-Like Spore Formers

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Md. Asaduzzaman Shishir

2018-02-01

Full Text Available The scarcity of hygienic drinking water is a normal phenomenon in the coastal areas of Bangladesh due to the high salinity of ground water. The inhabitants of this locality, therefore, live on alternative supplies of water including rain-fed pond water, and rainwater with persistent complex microbial interactions therein, often contaminated with life-threatening pathogens. Hence, this study was aimed at analyzing the prevalence of Vibrio cholerae (Vc in the alternative drinking waters of Mathbaria, a coastal subdistrict neighboring the Bay of Bengal, the efficacy of pond sand filter (PSF and the co-association among Bacillus-like spore formers (Sf and Vc. Vc presumably entrapped into the membrane filter was enriched in alkaline peptone water medium and was isolated on selective thiosulfate-citrate-bile salts-sucrose and taurocholate-tellurite-gelatin agar media. They were finally identified by immunochromatographic one step rapid test and serology test. A total of 26% Vc positive samples were obtained out of 100 [ponds—48, household (HH—29, and PSFs—23] where 13% cases were pathogenic (Vc O1 and 13% were non-pathogenic (Vc non-O1/non-O139. The distribution of Vc as observed was 33, 26, and 13.8% in waters derived from pond surface, PSF, and HH reservoirs, respectively, and for pathogenic type, it was 62.5%, 50%, and nil, respectively. Although none of the samples was identified with pathogenic Vc O139, the statistics represents a significant and augmentative risk of cholera outbreak in the focused area. The antibiotic sensitivity pattern in this study resembled the trend observed during last few years for Vc. The PSF demonstrated its inability to remove Vc from any of the samples and in addition, the filter itself was evidenced to be the source of pathogens and spores in further contamination and transmission. The development of biofilm in the PSF could be hypothesized as the reservoir in contaminating pathogen-free water samples. From the

Prevalence of Vibrio cholerae in Coastal Alternative Supplies of Drinking Water and Association with Bacillus-Like Spore Formers.

Science.gov (United States)

Shishir, Md Asaduzzaman; Mamun, Md Al; Mian, Md Mahmuduzzaman; Ferdous, Umme Tamanna; Akter, Noor Jahan; Suravi, Rajia Sultana; Datta, Suvamoy; Kabir, Md Ehsanul

2018-01-01

The scarcity of hygienic drinking water is a normal phenomenon in the coastal areas of Bangladesh due to the high salinity of ground water. The inhabitants of this locality, therefore, live on alternative supplies of water including rain-fed pond water, and rainwater with persistent complex microbial interactions therein, often contaminated with life-threatening pathogens. Hence, this study was aimed at analyzing the prevalence of Vibrio cholerae ( Vc ) in the alternative drinking waters of Mathbaria, a coastal subdistrict neighboring the Bay of Bengal, the efficacy of pond sand filter (PSF) and the co-association among Bacillus -like spore formers (Sf) and Vc . Vc presumably entrapped into the membrane filter was enriched in alkaline peptone water medium and was isolated on selective thiosulfate-citrate-bile salts-sucrose and taurocholate-tellurite-gelatin agar media. They were finally identified by immunochromatographic one step rapid test and serology test. A total of 26% Vc positive samples were obtained out of 100 [ponds-48, household (HH)-29, and PSFs-23] where 13% cases were pathogenic ( Vc O1) and 13% were non-pathogenic ( Vc non-O1/non-O139). The distribution of Vc as observed was 33, 26, and 13.8% in waters derived from pond surface, PSF, and HH reservoirs, respectively, and for pathogenic type, it was 62.5%, 50%, and nil, respectively. Although none of the samples was identified with pathogenic Vc O139, the statistics represents a significant and augmentative risk of cholera outbreak in the focused area. The antibiotic sensitivity pattern in this study resembled the trend observed during last few years for Vc . The PSF demonstrated its inability to remove Vc from any of the samples and in addition, the filter itself was evidenced to be the source of pathogens and spores in further contamination and transmission. The development of biofilm in the PSF could be hypothesized as the reservoir in contaminating pathogen-free water samples. From the test of

[The cholera epidemic in Latin America].

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Olsvik, O

1992-05-30

An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

[Microbiological characterization of non-O1 Vibrio cholerae isolated in Cuba].

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Bravo Fariñas, Laura; Fernández, Anabel; Ramírez, María M; Llop, Alina; Martínez, Gerardo; Hernández, Raquel I; Cabrera, Luis E; Morier, Luis; Fraga, Jorge; Núñez, Fidel A; Aguila, Adalberto

2007-01-01

The study of 422 non-01 Vibrio cholerae strains from nine provinces, 9 of them isolated from a water-borne disease outbreak, was performed. All the strains exhibited antimicrobial susceptibility and virulence factors. The nine strains from the outbreak were subjected to a DNA macrorestriction study based on the pulsed field electrophoresis technique. For the first time in Cuba and the Caribbean. The circulation of atypical non-01 V cholerae strains (resistent to vibriostatic compound 0129 and trimethoprim/sulfamethoxazole). The behavior of antimicrobial susceptibility evinced for the first time the circulation of two different resistence patterns in Cuba (ampicilline, trimethoprim/ sulfamethoxazole, sulfonamide and tetracycline, trimethoprim/ sulfamethoxazole, sulfonamide). The frequency of trimethoprim/ sulfamethoxazole-resistent strains was similar during the whole period of study. However, resistance to ampicilline decreased whereas resistance to tetracycline increased. The main found virulence factors were gelatinase, hemolysine, elastase and adherence to Hep-2 cells. On the other hand, the outbreak strains showed higher percentages than the others due to the presence of heat-liable toxin and fimbriae. The results of the molecular and epidemiological studies allowed giving a speedy and accurate response that explained the etiology of the first food-borne disease outbreak.

Epidemic waves of cholera in the last two decades in Mozambique.

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Langa, José Paulo; Sema, Cynthia; De Deus, Nilsa; Colombo, Mauro Maria; Taviani, Elisa

2015-07-04

Africa is increasingly affected by cholera. In Mozambique, cholera appeared in the early 1970s when the seventh pandemic entered Africa from the Indian subcontinent. In the following decades, several epidemics were registered in the country, the 1997-1999 epidemic being the most extended. Since then, Mozambique has been considered an endemic area for cholera, characterized by yearly outbreaks occurring with a seasonal pattern. At least three pandemic variants are thought to have originated in the Indian subcontinent and spread worldwide at different times. To understand the epidemiology of cholera in Mozambique, whether the disease re-emerges periodically or is imported by different routes of transmission, we investigated clinical V. cholerae O1 isolated during 1997-1999 and 2012-2014 epidemics. By detecting and characterizing seven genetic elements, the mobilome profile of each isolate was obtained. By comparing it to known seventh pandemic reference strains, it was possible to discern among different V. cholerae O1 variants active in the country. During 1997-1999, epidemic strains showed two different genetic profiles, both related to a pandemic clone that originated from India and was reported in other African countries in the 1990s. Isolates from 2012-2014 outbreaks showed a genetic background related to the pandemic strains currently active as the prevalent causative agent of cholera worldwide. Despite cholera being endemic in Mozambique, the epidemiology of the disease in the past 20 years has been strongly influenced by the cholera seventh pandemic waves that originated in the Indian subcontinent.

Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011-2015.

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Semá Baltazar, Cynthia; Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D Gessner, Bradford; Munier, Aline; A Mengel, Martin

2017-10-01

Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and control efforts during major cholera outbreaks in recent years.

A Animação de Imagens no 1.º Ciclo do Ensino Básico Programa CRIANÇAS PRIME1Rº do Serviço Educativo CINANIMA

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Paulo Oliveira Fernandes

2017-07-01

Full Text Available Este artigo apresenta o programa CRIANÇAS PRIME1Rº, uma iniciativa do Serviço Educativo CINANIMA – Festival Internacional de Cinema de Animação de Espinho, com o apoio da Direção-geral de Educação – Plano Nacional de Cinema, dirigido a crianças do 1.º ciclo do Ensino Básico, com o objetivo de proporcionar o contacto com a animação de imagens e a realização de filmes de animação em contexto educativo. Para além das questões técnicas associadas ao cinema de animação, este programa tem na sua base preocupações eminentemente pedagógicas, desenvolvendo-se através de metodologias de projeto e didática da imagem animada. No seu primeiro ano de desenvolvimento (ano letivo 2015/2016 estiveram envolvidas 139 crianças de 7 turmas do 1.º ciclo do ensino básico. No final do processo os filmes foram exibidos em duas sessões especiais inseridas no programa da 40ª edição do Festival CINANIMA, editados em suporte DVD e oferecidos a todos os alunos intervenientes, professores e parceiros deste programa.

Cholera in Azov area

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O. N. Domashenko

2015-01-01

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

Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011–2015

Science.gov (United States)

Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D. Gessner, Bradford; Munier, Aline; A. Mengel, Martin

2017-01-01

Background Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Methodology/Principal findings Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Conclusions/Significance Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and

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

Science.gov (United States)

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

2015-11-01

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

Poly[di-μ-aqua-diaquabis(μ7-oxalato-κ9O1:O1:O1,O2:O2:O2′:O2′,O1′:O1′calciumdicaesium

Directory of Open Access Journals (Sweden)

Hamza Kherfi

2013-09-01

Full Text Available In the title compound, [CaCs2(C2O42(H2O4]n, the Ca2+ ion, lying on a twofold rotation axis, is coordinated by four O atoms from two oxalate ligands and two bridging water molecules in an octahedral geometry. The Cs+ ion is coordinated by seven O atoms from six oxalate ligands, one bridging water and one terminal water molecule. The oxalate ligand displays a scarce high denticity. The structure contains parallel chain units runnig along [10-1], formed by two edge-sharing Cs polyhedra connected by CsO9 polyhedra connected by a face-sharing CaO6 octahedron. These chains are further linked by the oxalate ligands to build up a three-dimensional framework. O—H...O hydrogen bonds involving the water molecules and the carboxylate O atoms enhance the extended structure.

Occurrence in Mexico, 1998-2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage.

Science.gov (United States)

Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A; Huq, Anwar; Sack, R Bradley; Colwell, Rita R; Cravioto, Alejandro

2014-07-08

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ(-). Most CTXΦ(-) V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpA(ET) or a variant tcpA with noticeable sequence dissimilarity from tcpA(CL). The tcpA variants were not detected in 2005 after CTXΦ(+) ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005-2008 in Mexico were CTXΦ(+) ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ(-) ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ(+) ET isolated during 2004-2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru.

Biochemical and full genome sequence analyses of clinical Vibrio cholerae isolates in Mexico reveals the presence of novel V. cholerae strains.

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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. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries.

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Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

2017-01-01

Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs) in environmental ctx -negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples) collected from ten sites on the river (January and February 2014) were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA) was the most isolated gene. The cholera toxin (ctxAB) and non-O1 heat-stable (stn/sto) genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries

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Akebe Luther King Abia

2017-01-01

Full Text Available Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs in environmental ctx-negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples collected from ten sites on the river (January and February 2014 were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA was the most isolated gene. The cholera toxin (ctxAB and non-O1 heat-stable (stn/sto genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

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

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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.

Global climate and infectious disease: the cholera paradigm.

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Colwell, R R

1996-12-20

The origin of cholera has been elusive, even though scientific evidence clearly shows it is a waterborne disease. However, standard bacteriological procedures for isolation of the cholera vibrio from environmental samples, including water, between epidemics generally were unsuccessful. Vibrio cholerae, a marine vibrio, requiring salt for growth, enters into a dormant, viable but nonculturable stage when conditions are unfavorable for growth and reproduction. The association of Vibrio cholerae with plankton, notably copepods, provides further evidence for the environmental origin of cholera, as well as an explanation for the sporadic and erratic occurrence of cholera epidemics. On a global scale, cholera epidemics can now be related to climate and climatic events, such as El Niño, as well as the global distribution of the plankton host. Remote sensing, with the use of satellite imagery, offers the potential for predicting conditions conducive to cholera outbreaks or epidemics.

Occurrence in Mexico, 1998–2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage

Science.gov (United States)

Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A.; Huq, Anwar; Sack, R. Bradley; Colwell, Rita R.; Cravioto, Alejandro

2014-01-01

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ−. Most CTXΦ− V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpAET or a variant tcpA with noticeable sequence dissimilarity from tcpACL. The tcpA variants were not detected in 2005 after CTXΦ+ ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005–2008 in Mexico were CTXΦ+ ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ− ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ+ ET isolated during 2004–2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru. PMID:24958870

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

African Journals Online (AJOL)

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

Cholera and Shigellosis: Different Epidemiology but Similar Responses to Climate Variability

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Cash, Benjamin A.; Rodó, Xavier; Emch, Michael; Yunus, Md.; Faruque, Abu S. G.; Pascual, Mercedes

2014-01-01

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

Nanostructured magnesium oxide biosensing platform for cholera detection

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

2013-04-01

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

Structural organization of the transfer RNA operon I of Vibrio cholerae

Indian Academy of Sciences (India)

Unknown

[Ghatak A, Majumdar A and Ghosh R K 2005 Structural organization of the transfer RNA operon I of Vibrio cholerae: Differences ..... clonal relationship are of utmost importance. ... rately derived from environmental, nontoxigenic, non-O1.

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

Science.gov (United States)

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

2015-11-01

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

Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

Science.gov (United States)

Sinyange, Nyambe; Brunkard, Joan M; Kapata, Nathan; Mazaba, Mazyanga Lucy; Musonda, Kunda G; Hamoonga, Raymond; Kapina, Muzala; Kapaya, Fred; Mutale, Lwito; Kateule, Ernest; Nanzaluka, Francis; Zulu, James; Musyani, Chileshe Lukwesa; Winstead, Alison V; Davis, William W; N'cho, Hammad S; Mulambya, Nelia L; Sakubita, Patrick; Chewe, Orbie; Nyimbili, Sulani; Onwuekwe, Ezinne V C; Adrien, Nedghie; Blackstock, Anna J; Brown, Travis W; Derado, Gordana; Garrett, Nancy; Kim, Sunkyung; Hubbard, Sydney; Kahler, Amy M; Malambo, Warren; Mintz, Eric; Murphy, Jennifer; Narra, Rupa; Rao, Gouthami G; Riggs, Margaret A; Weber, Nicole; Yard, Ellen; Zyambo, Khozya D; Bakyaita, Nathan; Monze, Namani; Malama, Kennedy; Mulwanda, Jabbin; Mukonka, Victor M

2018-05-18

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

International dissemination of epidemic Vibrio cholerae by cargo ship ballast and other nonpotable waters.

Science.gov (United States)

McCarthy, S A; Khambaty, F M

1994-07-01

In 1991 and 1992, toxigenic Vibrio cholerae O1, serotype Inaba, biotype El Tor, was recovered from nonpotable (ballast, bilge, and sewage) water from five cargo ships docked in ports of the U.S. Gulf of Mexico. Four of these ships had taken on ballast water in cholera-infected countries; the fifth took on ballast in a noninfected country. Isolates examined by pulsed-field gel electrophoresis were indistinguishable from the Latin American epidemic strain, C6707; however, they differed significantly from the endemic Gulf Coast strain (VRL 1984), the sixth-pandemic strain (569-B), and a V. cholerae non-O1 strain isolated from a ship arriving from a foreign port. On the basis of our findings, the Food and Drug Administration recommended that the U.S. Coast Guard issue an advisory to shipping agents and captains requesting that ballast waters be exchanged on the high seas before entry of ships into U.S. ports.

Obtención de extractos de membrana externa de Vibrio cholerae O1, mediante el uso de diferentes detergentes

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José Luis Pérez

2006-04-01

Full Text Available En la actualidad existen dos variantes principales de vacunas orales contra el cólera: una basada en células inactivadas de diferentes biotipos y serotipos y otra basada en la administración de cepas vivas genéticamente atenuadas. Una vacuna por subunidades pudiera ser una variante muy atractiva. Este trabajo describe la purificación parcial y caracterización preliminar de extractos de proteínas de membrana externa-lipopolisacárido (PME-LPS, obtenidos a partir de Vibrio cholerae O1, con el interés de seleccionar un proteoliposoma que posteriormente será estructurado en forma de cocleatos para su uso por vía oral en humanos. Las preparaciones fueron obtenidas a través del uso de diferentes detergentes. La cantidad de LPS en cada preparación fue estimada mediante la determinación de las unidades endotóxicas en el ensayo del Limulus (LAL. La composición de cada muestra fue evaluada mediante SDS-PAGE y Dot Blot. La inoculación intranasal (IN en ratones Balb/c se utilizó para la evaluación de la inmunogenicidad de las preparaciones, y la respuesta inmune fue determinada por ELISA y el título de anticuerpos vibriocidas. El tamaño molecular de la preparación con mejores resultados en inmunogenicidad se estimó mediante la cromatografía en Sephacryl S-1000. Se obtuvieron diferentes perfiles electroforéticos de acuerdo con el tipo de detergente utilizado. El LPS fue identificado en todas las preparaciones y aquella obtenida con el SDS al 15% mostró la más baja relación proteínas/LPS y los mejores resultados en los ensayos de inmunogenicidad. Adicionalmente se comprobó que su tamaño molecular es similar al observado en el proteoliposoma de VAMENGOC- BC. La preparación obtenida con el SDS al 15% constituye un proteoliposoma, con capacidad para estimular altos niveles de anticuerpos IgG anti-LPS y altos títulos de anticuerpos vibriocidas, luego de su administración por vía intranasal en ratones. Estos resultados constituyen

Escape of O(3P), O(1D), and O(1S) from the Martian atmosphere

Science.gov (United States)

Fox, Jane L.; Hać, Aleksander B.

2018-01-01

We have computed here the escape probabilities, fluxes and rates for hot O atoms that are initially produced in the ground state and the first two excited metastable states, O(1D)and O(1S), in the Martian thermosphere by dissociative recombination of O2+. In order to compare our results with those of our previous calculations and with those of others, we have employed here the pre-MAVEN models that we have used previously. To compute the escape probabilities, we have employed the Monte Carlo escape code that has been described previously, but we here use for the first time energy-dependent elastic cross sections for collisions of the energetic O atoms with each of the twelve background species in our model. We also incorporate three mechanisms that interchange identities of the O(3P) and O(1D) atoms, including collisional excitation of O(3P) to O(1D), quenching of O(1D) to O(3P), and excitation exchange of O(1D) with O(3P). We find that the escape probabilities of O atoms that are produced initially as O(1D) are reduced compared to those in which these processes are not included, but the escape probabilities of O atoms that are initially produced as O(3P) are not significantly reduced. As a guide for our future research and those of other investigators, we review here what is known about the interactions of O atoms with other species in which the energies of the O atoms are altered, and several other sources of hot and escaping O, many of which have been suggested by other investigators. We will incorporate these data in a future MAVEN-like model.

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

Science.gov (United States)

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

2013-03-01

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

Oxidative and antibacterial activity of Mn3O4

International Nuclear Information System (INIS)

Chowdhury, Al-Nakib; Azam, Md. Shafiul; Aktaruzzaman, Md.; Rahim, Abdur

2009-01-01

Mn 3 O 4 nanoparticles with diameter ca. 10 nm were synthesized by the forced hydrolysis of Mn(II) acetate at 80 deg. C. The X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques were employed to study structural features and chemical composition of the nanoparticles. The unique oxidative activity of the Mn 3 O 4 nanoparticles was demonstrated in the polymerization and dye degradation reactions. On adding Mn 3 O 4 suspension to an acidic solution of aniline, yielded immediately green sediment of polyaniline (PANI). The organic dyes, viz., methylene blue (MB) and procion red (PR) were found to be completely decolorized from their aqueous solution on treating the dyes with Mn 3 O 4 suspension in acidic media. The Mn 3 O 4 nanoparticles also showed a clear antibacterial activity against the Vibrio cholerae, Shigella sp., Salmonella sp., and Escherichi coli bacteria that cause cholera, dysentery, typhoid, and diarrhea diseases, respectively.

Cell Vacuolation Caused by Vibrio cholerae Hemolysin

Science.gov (United States)

Figueroa-Arredondo, Paula; Heuser, John E.; Akopyants, Natalia S.; Morisaki, J. Hiroshi; Giono-Cerezo, Silvia; Enríquez-Rincón, Fernando; Berg, Douglas E.

2001-01-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (∼1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (∼16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses. PMID:11179335

Cell vacuolation caused by Vibrio cholerae hemolysin.

Science.gov (United States)

Figueroa-Arredondo, P; Heuser, J E; Akopyants, N S; Morisaki, J H; Giono-Cerezo, S; Enríquez-Rincón, F; Berg, D E

2001-03-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (approximately 1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (approximately 16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses.

The cocrystal μ-oxalato-κ4O1,O2:O1′,O2′-bis(aqua(nitrato-κO{[1-(2-pyridyl-κNethylidene]hydrazine-κN}copper(II μ-oxalato-κ4O1,O2:O1′,O2′-bis((methanol-κO(nitrato-κO{[1-(2-pyridyl-κNethylidene]hydrazine-κN}copper(II (1/1

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Youssouph Bah

2008-09-01

Full Text Available The title cocrystal, [Cu2(C2O4(NO32(C7H9N32(H2O2][Cu2(C2O4(NO32(C7H9N32(CH4O2], is a 1:1 cocrystal of two centrosymmetric CuII complexes with oxalate dianions and Schiff base ligands. In each molecule, the CuII centre is in a distorted octahedral cis-CuN2O4 environment, the donor atoms of the N,N′-bidentate Schiff base ligand and the bridging O,O′-bidentate oxalate group lying in the equatorial plane. In one molecule, a monodentate nitrate anion and a water molecule occupy the axial sites, and in the other, a monodentate nitrate anion and a methanol molecule occupy these sites. In the crystal structure, intermolecular N—H...O, O—H...O and N—H...N hydrogen bonds link the molecules into a network. Weak intramolecular N—H...O interactions are also observed.

O2(a1Δ) Quenching In The O/O2/O3 System

Science.gov (United States)

Azyazov, V. N.; Mikheyev, P. A.; Postell, D.; Heaven, M. C.

2010-10-01

The development of discharge singlet oxygen generators (DSOG's) that can operate at high pressures is required for the power scaling of the discharge oxygen iodine laser. In order to achieve efficient high-pressure DSOG operation it is important to understand the mechanisms by which singlet oxygen (O2(a1Δ)) is quenched in these devices. It has been proposed that three-body deactivation processes of the type O2(a1Δ)+O+M→2O2+M provide significant energy loss channels. To further explore these reactions the physical and reactive quenching of O2(a1Δ) in O(3P)/O2/O3/CO2/He/Ar mixtures has been investigated. Oxygen atoms and singlet oxygen molecules were produced by the 248 nm laser photolysis of ozone. The kinetics of O2(a1Δ) quenching were followed by observing the 1268 nm fluorescence of the O2a1Δ-X3∑ transition. Fast quenching of O2(a1Δ) in the presence of oxygen atoms and molecules was observed. The mechanism of the process has been examined using kinetic models, which indicate that quenching by vibrationally excited ozone is the dominant reaction.

O2(a1Δ) Quenching In The O/O2/O3 System

International Nuclear Information System (INIS)

Azyazov, V. N.; Mikheyev, P. A.; Postell, D.; Heaven, M. C.

2010-01-01

The development of discharge singlet oxygen generators (DSOG's) that can operate at high pressures is required for the power scaling of the discharge oxygen iodine laser. In order to achieve efficient high-pressure DSOG operation it is important to understand the mechanisms by which singlet oxygen (O 2 (a 1 Δ)) is quenched in these devices. It has been proposed that three-body deactivation processes of the type O 2 (a 1 Δ)+O+M→2O 2 +M provide significant energy loss channels. To further explore these reactions the physical and reactive quenching of O 2 (a 1 Δ) in O( 3 P)/O 2 /O 3 /CO 2 /He/Ar mixtures has been investigated. Oxygen atoms and singlet oxygen molecules were produced by the 248 nm laser photolysis of ozone. The kinetics of O 2 (a 1 Δ) quenching were followed by observing the 1268 nm fluorescence of the O 2 a 1 Δ-X 3 Σ transition. Fast quenching of O 2 (a 1 Δ) in the presence of oxygen atoms and molecules was observed. The mechanism of the process has been examined using kinetic models, which indicate that quenching by vibrationally excited ozone is the dominant reaction.

Pulmão e transplante renal

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Patrícia Caetano Mota

2009-11-01

Full Text Available Resumo: O transplante renal é o transplante de órgãos sólidos mais frequente, sendo os transplantados renais alvo de complicações pulmonares inerentes à própria terapêutica imunossupressora, as quais constituem, por vezes, um desafio diagnóstico e terapêutico.Objectivo: Avaliar os doentes admitidos na Unidade de Transplante Renal (UTR do Hospital de S. João com o diagnóstico de patologia respiratória.Material e métodos: Estudo retrospectivo de todos os doentes admitidos na UTR por doença respiratória, durante um período de 12 meses.Resultados: Foram incluídos 36 doentes, com uma média de idades de 55,2 (±13,4 anos; 61,1% do sexo masculino. Os esquemas imunossupressores mais utilizados foram: prednisolona e micofenolato mofetil com ciclosporina (38,9% ou tacrolimus (22,2% ou rapamicina (13,9%. Trinta e um doentes (86,1% apresentaram doença infecciosa respiratória. Neste grupo destacaram-se: 23 casos (74,2% de pneumonia, 5 casos (16,1% de infecção oportunista, 2 (6,5% de traqueobronquite, e 1 (3,2% de abcessos pulmonares. O agente etiológico foi identificado em 7 casos (22,6%. Cinco doentes (13,9% apresentaram doença pulmonar iatrogénica pela rapamicina. Em 15 doentes (41,7% foi necessário recorrer à realização de broncofibroscopia, diagnóstica em 10 casos (66,7%. O tempo médio de internamento foi de 17,1 (±18,5 dias, e não se verificou nenhum óbito.Conclusão: A infecção constituiu a principal complicação pulmonar no grupo de doentes estudado. O diagnóstico de doença pulmonar induzida por fármacos implica reconhecimento das suas características e monitorização rigorosa dos níveis séricos dos mesmos. O recurso a técnicas de diagnóstico invasivas contribuiu para maior precocidade e especificidade terapêuticas.Rev Port Pneumol 2009; XV (6: 1073-1099 Abstract: Renal transplantation is the most common type of solid organ transplantation and kidney transplant recipients are susceptible to pulmonary

Radiation decontamination of Peruvian marine ''lead snail'' (Thais chocolata) inoculated with Vibrio cholerae O1 El Tor

International Nuclear Information System (INIS)

Torres, Z.; Arias, F.

2001-01-01

In vivo studies were conducted using marine snails (Thais chocolata) artificially contaminated in a tank containing sea water inoculated with a pure culture of Vibrio cholerae, such that 10 5 colony forming units per gram (CFU/g) were uptaken by the mollusks in 1.5 h. A radiation D 10 value of 0.12 kGy was determined for V. cholerae upon subsequent irradiation of the live snails at doses in the range 0.0-4.0 kGy. A second series of tests were conducted using naturally contaminated, non-inoculated snails, shelled and packaged simulating commercial procedures, irradiated at 0.0-3.0 kGy, and stored at 2-4 deg. C. These tests indicated that a dose of 2.0 kGy was optimal to extend the microbiological shelf-life of the snails to 21 days without inducing significant adverse sensory or chemical effects. Non-irradiated snails similarly treated and stored spoiled after only seven days. (author)

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

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Daniel Unterweger

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

Overexpression, purification, crystallization and preliminary X-ray analysis of CheY4 from Vibrio cholerae O395

International Nuclear Information System (INIS)

Biswas, Maitree; Khamrui, Susmita; Sen, Udayaditya; Dasgupta, Jhimli

2011-01-01

The chemotaxis response regulator CheY4 from V. cholerae has been cloned, overexpressed, purified and crystallized in monoclinic and hexagonal space groups; the crystals diffracted to 1.67 and 1.9 Å resolution, respectively. Chemotaxis and motility greatly influence the infectivity of Vibrio cholerae, although the role of chemotaxis genes in V. cholerae pathogenesis is poorly understood. In contrast to the single copy of CheY found in Escherichia coli and Salmonella typhimurium, four CheYs (CheY1–CheY4) are present in V. cholerae. While insertional disruption of the cheY4 gene results in decreased motility, insertional duplication of this gene increases motility and causes enhanced expression of the two major virulence genes. Additionally, cheY3/cheY4 influences the activation of the transcription factor NF-κB, which triggers the generation of acute inflammatory responses. V. cholerae CheY4 was cloned, overexpressed and purified by Ni–NTA affinity chromatography followed by gel filtration. Crystals of CheY4 grown in space group C2 diffracted to 1.67 Å resolution, with unit-cell parameters a = 94.4, b = 31.9, c = 32.6 Å, β = 96.5°, whereas crystals grown in space group P3 2 21 diffracted to 1.9 Å resolution, with unit-cell parameters a = b = 56.104, c = 72.283 Å, γ = 120°

Determination of tetracycline resistance genes in Vibrio cholerae O1 biotype El Tor serotype Inaba strains isolated from outbreaks occurred in Iran in 2013

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Azin Khany

2016-05-01

Full Text Available V. cholerae is the causative agent of potentially life threatening diarrheal disease named as cholera. Cholera is an endemic disease in Iran. Encountered increasing resistance of V. cholerae to commonly used antibiotics such as tetracycline has led to major challenges in the treatment of this disease .The present study was carried out to determine the prevalence of drug resistance as well as molecular bases of resistant V.cholerae strains which were isolated from patients in cholera outbreaks during summer of 2013 in Iran. Susceptibly testing was performed on V.cholerae strains isolated from stool of patients suffering from cholera in Iranian reference health laboratory by E -test MIC method as recommended by CLSI guideline. Antibiotic strips used included Ampicillin, Ciprofloxacin, Nalidixic acid, Cefixime , Tetracycline, Erythromycin and Trimethoprim-sulfamethoxazole .Regarding observed dominant pattern of tetracycline resistance comparing to results of previous years ,we decided to confirm the resistance by detecting the tetA , tetB and tetC by Polymerase chain reaction method. The results of antibiotic susceptibility testing revealed 100% resistance of isolated strains to tetracycline. Data obtained from PCR reaction on resistant strains for tetA, tetB and tetC showed that 45(44.1%, 37(36.2% and 70(68.6% were containing tetA, tetB and tetC gene respectively. Moreover, the frequency of tetA+tetB, tetA+C, tetB+tetC , tetA+tetB+tetC also were determined as 9(8.8%, 32(31.3%, 19(18.6% and 8(7.8% respectively. This study revealed the pattern of drug resistance distribution of isolates harboring tetA, tetB, tetC genes in relation to sex, age and nationality of patients and the cities where the cases were reported. A significant correlation was obtained between reported geographical incidence and drug resistant strains.

Improved laboratory capacity is required to respond better to future cholera outbreaks in Papua New Guinea

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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.

Influence of water temperature and salinity on seasonal occurrences of Vibrio cholerae and enteric bacteria in oyster-producing areas of Veracruz, México.

Science.gov (United States)

Castañeda Chávez, Maria del Refugio; Pardio Sedas, Violeta; Orrantia Borunda, Erasmo; Lango Reynoso, Fabiola

2005-12-01

The influence of temperature and salinity on the occurrence of Vibrio cholerae, Escherichia coli and Salmonella spp. associated with water and oyster samples was investigated in two lagoons on the Atlantic Coast of Veracruz, Mexico over a 1-year period. The results indicated that seasonal salinity variability and warm temperatures, as well as nutrient influx, may influence the occurrence of V. cholera. non-O1 and O1. The conditions found in the Alvarado (31.12 degrees C, 6.27 per thousand, pH=8.74) and La Mancha lagoons (31.38 degrees C, 24.18 per thousand, pH=9.15) during the rainy season 2002 favored the occurrence of V. cholera O1 Inaba enterotoxin positive traced in oysters. Vibrio alginolyticus was detected in Alvarado lagoon water samples during the winter season. E. coli and Salmonella spp. were isolated from water samples from the La Mancha (90-96.7% and 86.7-96.7%) and Alvarado (88.6-97.1% and 88.6-100%) lagoons. Occurrence of bacteria may be due to effluents from urban, agricultural and industrial areas.

Cholera between 1991 and 1997 in Mexico Was Associated with Infection by Classical, El Tor, and El Tor Variants of Vibrio cholerae▿

OpenAIRE

Alam, Munirul; Nusrin, Suraia; Islam, Atiqul; Bhuiyan, Nurul A.; Rahim, Niaz; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Gil, Ana I.; Watanabe, Haruo; Morita, Masatomo; Nair, G. Balakrish; Cravioto, Alejandro

2010-01-01

Vibrio cholerae O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of V. cholerae causing endemic cholera in Latin America is lacking. The present ...

The small nucleoid protein Fis is involved in Vibrio cholerae quorum sensing.

Science.gov (United States)

Lenz, Derrick H; Bassler, Bonnie L

2007-02-01

Quorum sensing is a process of cell-cell communication that bacteria use to relay information to one another about the cell density and species composition of the bacterial community. Quorum sensing involves the production, secretion and population-wide detection of small signalling molecules called autoinducers. This process allows bacteria to synchronize group behaviours and act as multicellular units. The human pathogen, Vibrio cholerae, uses quorum sensing to co-ordinate such complex behaviours as pathogenicity and biofilm formation. The quorum-sensing circuit of V. cholerae consists of two autoinducer/sensor systems, CAI-1/CqsS and AI-2/LuxPQ, and the VarS/A-CsrA/BCD growth-phase regulatory system. Genetic analysis suggests that an additional regulatory arm involved in quorum sensing exists in V. cholerae. All of these systems channel information into the histidine phosphotransfer protein, LuxU, and/or the response regulator, LuxO. LuxO, when phosphorylated, activates the expression of four genes encoding the Qrr (quorum regulatory RNAs) small RNAs (sRNAs). The Qrr sRNAs destabilize the hapR transcript encoding the master regulator of quorum sensing, HapR. Here we identify the nucleoid protein Fis as playing a major role in the V. cholerae quorum-sensing circuit. Fis fulfils the predictions required to be the putative additional component that inputs information into the cascade: its expression is regulated in a growth phase-dependent manner; it requires LuxO but acts independently of LuxU, and it regulates all four qrr genes and, in turn, HapR by directly binding to the qrr gene promoters and modulating their expression.

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

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IGP Dhinarananta

2014-01-01

Full Text Available 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 usage process.Type of ice that widely used were cube and tube ice which each of them have a differentin making and usage process. The purpose of this study is to obtain the contamination ofV.cholera in cube and tube ice. The method of this study is descriptive observationalstudy with quota sampling technique. Sample were obtained from a restaurants andstreet vendor which use a block and tube ice with total 10 sample and 5 for each type ofice.Sample then cultured in Alkaline Peptone Water(APW and Thiosulfate Citrate Bilesalt Sucrose(TCBS agar. Bacteriacolony then identified using a gram staining andLatex Serotyping. The result are 3 over 5 (60% sample of cube ice contaminated byV.cholera O1 Inaba serotype and 3 over 5 (60% sample of tube ice contaminated byV.cholera O1 Inaba serotype.

Density of Na2O-Li2O-SiO2-B2O3 Molten Slag at 1 803-1 873 K

Institute of Scientific and Technical Information of China (English)

XIAO Feng; FANG Liang

2004-01-01

The density of three kinds of molten slags was measured by modified sessile drop method at 1 803-1 873 K. The density of molten slag is found to decrease with increasing temperature. The temperature coefficients of Na2O-Li2O-SiO2 and Li2O-SiO2-B2O3 slag are smaller than that of Na2O-B2O3 slag. The molar volume of slags increases with increasing temperature.

Effectiveness of an oral cholera vaccine campaign to prevent clinically-significant cholera in Odisha State, India.

Science.gov (United States)

Wierzba, Thomas F; Kar, Shantanu K; Mogasale, Vijayalaxmi V; Kerketta, Anna S; You, Young Ae; Baral, Prameela; Khuntia, Hemant K; Ali, Mohammad; Kim, Yang Hee; Rath, Shyam Bandhu; Bhattachan, Anuj; Sah, Binod

2015-05-15

A clinical trial conducted in India suggests that the oral cholera vaccine, Shanchol, provides 65% protection over five years against clinically-significant cholera. Although the vaccine is efficacious when tested in an experimental setting, policymakers are more likely to use this vaccine after receiving evidence demonstrating protection when delivered to communities using local health department staff, cold chain equipment, and logistics. We used a test-negative, case-control design to evaluate the effectiveness of a vaccination campaign using Shanchol and validated the results using a cohort approach that addressed disparities in healthcare seeking behavior. The campaign was conducted by the local health department using existing resources in a cholera-endemic area of Puri District, Odisha State, India. All non-pregnant residents one year of age and older were offered vaccine. Over the next two years, residents seeking care for diarrhea at one of five health facilities were asked to enroll following informed consent. Cases were patients seeking treatment for laboratory-confirmed V. cholera-associated diarrhea. Controls were patients seeking treatment for V. cholerae negative diarrhea. Of 51,488 eligible residents, 31,552 individuals received one dose and 23,751 residents received two vaccine doses. We identified 44 V. cholerae O1-associated cases and 366 non V. cholerae diarrhea controls. The adjusted protective effectiveness for persons receiving two doses was 69.0% (95% CI: 14.5% to 88.8%), which is similar to the adjusted estimates obtained from the cohort approach. A statistical trend test suggested a single dose provided a modicum of protection (33%, test for trend, p=0.0091). This vaccine was found to be as efficacious as the results reported from a clinical trial when administered to a rural population using local health personnel and resources. This study provides evidence that this vaccine should be widely deployed by public health departments in

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Phase diagram study for the PbO-ZnO-CaO-SiO_2 -“Fe_2O_3 ” system in air with CaO/SiO_2 in 1.1 and PbO/(CaO+SiO_2) in 2.4 weight ratios

International Nuclear Information System (INIS)

Lopez-Rodriguez, Josue; Romero-Serrano, Antonio; Hernandez-Ramirez, Aurelio; Cruz-Ramirez, Alejandro; Almaguer-Guzman, Isaias; Benavides-Perez, Ricardo; Flores-Favela, Manuel

2017-01-01

An experimental study on the phase equilibrium and the liquidus isotherms for the PbO-ZnO-CaO-SiO_2 -“Fe_2O_3 ” system with CaO/SiO_2 in 1.1 and PbO/(CaO+SiO_2) in 2.4 weight ratios, respectively, was carried out in the temperature range 1100-1300 deg C (1373-1573 K). High temperature phases were determined by the equilibrium-quenching method. Results are presented in the form of pseudo-ternary sections “Fe_2O_3 ”-ZnO-(PbO+CaO+SiO_2). X-Ray diffraction (XRD) and SEM-EDS results showed that the phase equilibria in this system are dominated by the high melting temperature spinel and zincite phases. It was observed that if the system is at a temperature below 1300 deg C and the total (Fe_2O_3 + ZnO) is greater than 20 wt%, spinel and/or zincite will be present in the slag system. As an application of the phase diagram, the liquid phase compositions below the liquidus surface were estimated, then their viscosities were calculated using FACTSage software. (author)

Anethole inhibits growth of recently emerged multidrug resistant toxigenic Vibrio cholerae O1 El Tor variant strains in vitro

OpenAIRE

ZAHID, M. Shamim Hasan; AWASTHI, Sharda Prasad; HINENOYA, Atsushi; YAMASAKI, Shinji

2015-01-01

To search natural compounds having inhibitory effect on bacterial growth is important, particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens. Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent of diarrheal disease cholera, is becoming a great concern. As an approach of searching new antimicrobial agents, here, we show that anethole, a well-studied natural component of sweet fennel and star anise seeds, could potentially inhibit the grow...

Vibrios among patients of good socioeconomic conditions during the cholera epidemic in Recife, Brazil Vibriões coléricos e não coléricos entre pacientes de boas condições sódo-econômicas durante a epidemia de coléra no Recife, Brasil

Directory of Open Access Journals (Sweden)

Vera Magalhães

1993-08-01

Full Text Available Between March and July, 1992, we screened for Vibrio all fecal samples submitted for bacteriologic diagnosis at a private clinical laboratory in Recife. Of 1435 cultures examined only 1 (0.07% was positive for V.cholerae 01, biovar Eltor, serovar Inaba, but 17 (1.2% yielded non-cholera Vibrio (V.cholerae non-01; V.fluvialis; V.furnissii, V.parahaemolyticus and Vibrio spp. Thus, V.cholerae 01, differently of other enteropathogenic vibrios, spared individuals of good socioeconomic conditions even during the cholera epidemic, which made hundreds of victims in the neighboring slums.Entre março e julho de 1992, pesquisou-se Vibrio em todos os espécimes fecais enviados para diagnóstico bacteriológico a um laboratório clínico privado do Recife. De 1435 culturas examinadas apenas 1 (0.07% foi positiva para V.cholerae 01, biovar Eltor, sorovar Inaba, porém 17 (1,2% forneceram outras espécies de Vibrio (V.cholerae nao-01; V.fluvialis; V.furnissii; V.parahaemolyticus e Vibrio spp. Portanto, V.cholerae 01, diferentemente de outros vibriões entero patogênicos, poupou indivíduos de boas condições sócio-econômicas, mesmo durante uma epidemia de cólera que atingiu centenas de pessoas nas favelas vizinhas.

O2(a1Δ) quenching in O/O2/O3/CO2/He/Ar mixtures

Science.gov (United States)

Azyazov, V. N.; Mikheyev, P. A.; Postell, D.; Heaven, M. C.

2010-02-01

The development of discharge singlet oxygen generators (DSOG's) that can operate at high pressures is required for the power scaling of the discharge oxygen iodine laser. In order to achieve efficient high-pressure DSOG operation it is important to understand the mechanisms by which singlet oxygen (O2(a1Δ)) is quenched in these devices. It has been proposed that three-body deactivation processes of the type O2(a1Δ))+O+M-->2O2+M provide significant energy loss channels. To further explore these reactions the physical and reactive quenching of O2(a1Δ)) in O(3P)/O2/O3/CO2/He/Ar mixtures has been investigated. Oxygen atoms and singlet oxygen molecules were produced by the 248 nm laser photolysis of ozone. The kinetics of O2(a1Δ)) quenching were followed by observing the 1268 nm fluorescence of the O2 a1Δ-X3Ε transition. Fast quenching of O2(a1Δ)) in the presence of oxygen atoms and molecules was observed. The mechanism of the process has been examined using kinetic models, which indicate that quenching by vibrationally excited ozone is the dominant reaction.

Cholera ante portas – The re-emergence of cholera in Kinshasa after a ten-year hiatus

Science.gov (United States)

Bompangue, Didier; Vesenbeckh, Silvan Manuel; Giraudoux, Patrick; Castro, Marcia; Muyembe, Jean-Jacques; Kebela Ilunga, Benoît; Murray, Megan

2012-01-01

Background: Cholera is an endemic disease in certain well-defined areas in the east of the Democratic Republic of Congo (DRC). The west of the country, including the mega-city Kinshasa, has been free of cases since mid 2001 when the last outbreak ended. Methods and Findings: We used routinely collected passive surveillance data to construct epidemic curves of the cholera cases and map the spatio-temporal progress of the disease during the first 47 weeks of 2011. We compared the spatial distribution of disease spread to that which occurred in the last cholera epidemic in Kinshasa between 1996 and 2001. To better understand previous determinants of cholera spread in this region, we conducted a correlation analysis to assess the impact of rainfall on weekly health zone cholera case counts between December 1998 and March 2001 and a Generalized Linear Model (GLM) regression analysis to identify factors that have been associated with the most vulnerable health zones within Kinshasa between October 1998 and June 1999. In February 2011, cholera reemerged in a region surrounding Kisangani and gradually spread westwards following the course of the Congo River to Kinshasa, home to 10 million people. Ten sampled isolates were confirmed to be Vibrio cholerae O1, biotype El Tor, serotype Inaba, resistant to trimethoprim-sulfa, furazolidone, nalidixic acid, sulfisoxaole, and streptomycin, and intermediate resistant to Chloramphenicol. An analysis of a previous outbreak in Kinshasa shows that rainfall was correlated with case counts and that health zone population densities as well as fishing and trade activities were predictors of case counts. Conclusion: Cholera is particularly difficult to tackle in the DRC. Given the duration of the rainy season and increased riverine traffic from the eastern provinces in late 2011, we expect further increases in cholera in the coming months and especially within the mega-city Kinshasa. We urge all partners involved in the response to remain

Single Nucleotide Polymorphisms in Regulator-Encoding Genes Have an Additive Effect on Virulence Gene Expression in a Vibrio cholerae Clinical Isolate.

Science.gov (United States)

Carignan, Bailey M; Brumfield, Kyle D; Son, Mike S

2016-01-01

Vibrio cholerae is the etiological agent of the infectious disease cholera, which is characterized by vomiting and severe watery diarrhea. Recently, V. cholerae clinical isolates have demonstrated increased virulence capabilities, causing more severe symptoms with a much higher rate of disease progression than previously observed. We have identified single nucleotide polymorphisms (SNPs) in four virulence-regulatory genes (hapR, hns, luxO, and vieA) of a hypervirulent V. cholerae clinical isolate, MQ1795. Herein, all SNPs and SNP combinations of interest were introduced into the prototypical El Tor reference strain N16961, and the effects on the production of numerous virulence-related factors, including cholera toxin (CT), the toxin-coregulated pilus (TCP), and ToxT, were analyzed. Our data show that triple-SNP (hapR hns luxO and hns luxO vieA) and quadruple-SNP combinations produced the greatest increases in CT, TCP, and ToxT production. The hns and hns luxO SNP combinations were sufficient for increased TCP and ToxT production. Notably, the hns luxO vieA triple-SNP combination strain produced TCP and ToxT levels similar to those of MQ1795. Certain SNP combinations (hapR and hapR vieA) had the opposite effect on CT, TCP, and ToxT expression. Interestingly, the hns vieA double-SNP combination strain increased TCP production while decreasing CT production. Our findings suggest that SNPs identified in the four regulatory genes, in various combinations, are associated with increased virulence capabilities observed in V. cholerae clinical isolates. These studies provide insight into the evolution of highly virulent strains. IMPORTANCE Cholera, an infectious disease of the small intestine caused by the aquatic bacterium Vibrio cholerae, often results in vomiting and acute watery diarrhea. If left untreated or if the response is too slow, the symptoms can quickly lead to extreme dehydration and ultimately death of the patient. Recent anecdotal evidence of cholera

Oxidative and antibacterial activity of Mn{sub 3}O{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Al-Nakib, E-mail: nakib@chem.buet.ac.bd [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Azam, Md. Shafiul, E-mail: azam@ualberta.ca [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Aktaruzzaman, Md.; Rahim, Abdur [Department of Chemistry, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh)

2009-12-30

Mn{sub 3}O{sub 4} nanoparticles with diameter ca. 10 nm were synthesized by the forced hydrolysis of Mn(II) acetate at 80 deg. C. The X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques were employed to study structural features and chemical composition of the nanoparticles. The unique oxidative activity of the Mn{sub 3}O{sub 4} nanoparticles was demonstrated in the polymerization and dye degradation reactions. On adding Mn{sub 3}O{sub 4} suspension to an acidic solution of aniline, yielded immediately green sediment of polyaniline (PANI). The organic dyes, viz., methylene blue (MB) and procion red (PR) were found to be completely decolorized from their aqueous solution on treating the dyes with Mn{sub 3}O{sub 4} suspension in acidic media. The Mn{sub 3}O{sub 4} nanoparticles also showed a clear antibacterial activity against the Vibrio cholerae, Shigella sp., Salmonella sp., and Escherichi coli bacteria that cause cholera, dysentery, typhoid, and diarrhea diseases, respectively.

Pulmão e transplante renal Lung and renal transplantation

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Patrícia Caetano Mota

2009-11-01

Full Text Available O transplante renal é o transplante de órgãos sólidos mais frequente, sendo os transplantados renais alvo de complicações pulmonares inerentes à própria terapêutica imunossupressora, as quais constituem, por vezes, um desafio diagnóstico e terapêutico. Objectivo: Avaliar os doentes admitidos na Unidade de Transplante Renal (UTR do Hospital de S. João com o diagnóstico de patologia respiratória. Material e métodos: Estudo retrospectivo de todos os doentes admitidos na UTR por doença respiratória, durante um período de 12 meses. Resultados: Foram incluídos 36 doentes, com uma média de idades de 55,2 (±13,4 anos; 61,1% do sexo masculino. Os esquemas imunossupressores mais utilizados foram: prednisolona e micofenolato mofetil com ciclosporina (38,9% ou tacrolimus (22,2% ou rapamicina (13,9%. Trinta e um doentes (86,1% apresentaram doença infecciosa respiratória. Neste grupo destacaram-se: 23 casos (74,2% de pneumonia, 5 casos (16,1% de infecção oportunista, 2 (6,5% de traqueobronquite, e 1 (3,2% de abcessos pulmonares. O agente etiológico foi identificado em 7 casos (22,6%. Cinco doentes (13,9% apresentaram doença pulmonar iatrogénica pela rapamicina. Em 15 doentes (41,7% foi necessário recorrer à realização de broncofibroscopia, diagnóstica em 10 casos (66,7%. O tempo médio de internamento foi de 17,1 (±18,5 dias, e não se verificou nenhum óbito. Conclusão: A infecção constituiu a principal complicação pulmonar no grupo de doentes estudado. O diagnóstico de doença pulmonar induzida por fármacos implica reconhecimento das suas características e monitorização rigorosa dos níveis séricos dos mesmos. O recurso a técnicas de diagnóstico invasivas contribuiu para maior precocidade e especificidade terapêuticas.Renal transplantation is the most common type of solid organ transplantation and kidney transplant recipients are susceptible to pulmonary complications of immunosuppressive therapy, which are a

Cobalt Oxide Catalysts Supported on CeO2–TiO2 for Ethanol Oxidation and N2O Decomposition.

Czech Academy of Sciences Publication Activity Database

Jirátová, Květa; Kovanda, F.; Balabánová, Jana; Koloušek, D.; Klegová, A.; Pacultová, K.; Obalová, L.

2017-01-01

Roč. 12, č. 1 (2017), s. 121-139 ISSN 1878-5190. [Pannonian Symposium on Catalysis. Siófok, 19.09.2016-23.09.2016] R&D Projects: GA ČR GA14-13750S Institutional support: RVO:67985858 Keywords : cobalt oxide catalysts * ethanol total oxidation * N2O decomposition Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 1.264, year: 2016

Architectural Processes and Physicochemical Properties of CoO/ZnO and Zn 1− x Co x O/Co 1− y Zn y O Nanocomposites

KAUST Repository

Yao, Ke Xin

2009-01-29

In this work we synthesized two inverse kinds of cobalt and zinc oxide nanocomposites (CoO/ZnO and Zn1-xCoxO/Co 1-yZnyO) and compared methodologistic features observed from the syntheses. The binary oxide system chosen herein is because divalent cobalt and zinc have very similar ion radii, and they interdiffuse easily when forming doped structures. A "two-pot" process was devised for the CoO/ZnO composites, in which mesocrystalline cores of CoO were formed first, followed by introduction of an overlayer of ZnO nanoparticles to the core surfaces. In contrast, a "one-pot" process was developed for the Zn1-xCoxO/Co1-yZnyO composites. In particular, hollow and/or multishelled Zn1-xCoxO cores (in wurtzite phase) serve as a support for the nanospheres of Co 1-yZnyO (in rock-salt phase) in this latter method. Our findings indicate that while "multi-pot" synthesis is a prevailing methodology for composite nanoparticles, simpler "one-pot" synthesis can be an effective approach for preparation of more complex nanocomposite materials, especially for interdoped metal oxides. As an example, our as-prepared binary oxide composites Zn1-xCoxO/Co 1-yZnyO have shown good catalytic activity for oxidation of carbon monoxide at relatively low reaction temperatures. © 2009 American Chemical Society.

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

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Rolf S Kaas

Full Text Available The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE elements were identified and annotated. A global phylogeny (378 genomes was inferred using a single nucleotide polymorphism (SNP analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

Cholera dynamics with Bacteriophage infection: A mathematical study

International Nuclear Information System (INIS)

Misra, A.K.; Gupta, Alok; Venturino, Ezio

2016-01-01

Highlights: • A mathematical model for the biological control of cholera has been proposed. • The feasibility and stability of all the equilibria have been investigated. • The ODE model is found to exhibit Hopf-bifurcation. • Conditions of global asymptotic stability have been obtained. • The impact of important parameters on cholera spread has been shown. - Abstract: Mathematical modeling of waterborne diseases, such as cholera, including a biological control using Bacteriophage viruses in the aquatic reservoirs is of great relevance in epidemiology. In this paper, our aim is twofold: at first, to understand the cholera dynamics in the region around a water body; secondly, to understand how the spread of Bacteriophage infection in the cholera bacterium V. cholerae controls the disease in the human population. For this purpose, we modify the model proposed by Codeço, for the spread of cholera infection in human population and the one proposed by Beretta and Kuang, for the spread of Bacteriophage infection in the bacteria population [1, 2]. We first discuss the feasibility and local asymptotic stability of all the possible equilibria of the proposed model. Further, in the numerical investigation, we have found that the parameter ϕ, called the phage adsorption rate, plays an important role. There is a critical value, ϕ c , at which the model possess Hopf-bifurcation. For lower values than ϕ c , the equilibrium E * is unstable and periodic solutions are observed, while above ϕ c , the equilibrium E * is locally asymptotically stable, and further shown to be also globally asymptotically stable. We investigate the effect of the various parameters on the dynamics of the infected humans by means of numerical simulations.

Detection mechanism and characteristics of ZnO-based N2O sensors operating with photons

Science.gov (United States)

Jeong, T. S.; Yu, J. H.; Mo, H. S.; Kim, T. S.; Youn, C. J.; Hong, K. J.

2013-11-01

N2O sensors made with ZnO-based ZnCdO films were grown on Pyrex substrates by using the RF co-sputtering method. The structure of the N2O sensor was electrode/sensor/glass/illuminant. The mechanism of the photo-assisted oxidation and reduction process on the surface of the N2O sensors was investigated using light from a UV lamp and violet light emitting diode (LED). For photon exposure wavelengths of 365 and 405 nm, the sensitivity of the ZnO-based ZnCdO sensors was measured. From these measurements, the values of the sensitivity of the sensors with x = 0, 0.01, and 0.05 were found to be S = 1.44, 1.39, and 1.33 under LED light with a wavelength of 405 nm, respectively. These sensitivities were compared to those of SnO2 and WO3 materials measured at operating temperatures of 300-600 °C. Also, under exposure with UV light, the response times were observed to be 130 to 270 sec. These response times were slightly slower than that for the traditional method of thermal heating. However, they indicate that the described photon exposure method for N2O detection can replace the conventional heating mode. Consequently, we demonstrated that portable N2O sensors for room-temperature operation could be fabricated without thermal heating.

KMoWP3O12, a tunnel structure of the KMo2O12-type

International Nuclear Information System (INIS)

Benmoussa, A.; Leclaire, A.; Grandin, A.; Raveau, B.

1989-01-01

Potassium molybdotungstotriphosphate(V), KMoWP 3 O 12 , M r =603.80, orthorhombic, Pbcm, a=8.8180(6), b=9.1574(8), c=12.3836(8) A, V=1000.0(2) A 3 , Z=4, D x =4.01 Mg m -3 , λ(Mo Kα)=0.71073 A, μ=13.9 mm -1 , T=294 K, F(000)=276, R=0.035 and wR=0.042 for 2291 observed reflections. The framework is built up from MoO 6 octahedra and PO 4 tetrahedra which delimit tunnels running along b, where the K ions are located. The structure leads to the formula KMoWO(PO 4 )(P 2 O 7 ). (orig.)

10 CFR 1.39 - Office of Human Resources.

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Office of Human Resources. 1.39 Section 1.39 Energy... § 1.39 Office of Human Resources. The Office of Human Resources— (a) Plans and implements NRC policies... agency's human resources; (b) Provides labor relations and personnel policy guidance and supporting...

Phase diagram study for the PbO-ZnO-CaO-SiO{sub 2} -“Fe{sub 2}O{sub 3} ” system in air with CaO/SiO{sub 2} in 1.1 and PbO/(CaO+SiO{sub 2}) in 2.4 weight ratios

Energy Technology Data Exchange (ETDEWEB)

Lopez-Rodriguez, Josue; Romero-Serrano, Antonio; Hernandez-Ramirez, Aurelio; Cruz-Ramirez, Alejandro, E-mail: romeroipn@hotmail.com [Instituto Politecnico Nacional-ESIQIE, Zacatenco, Mexico City (Mexico); Almaguer-Guzman, Isaias; Benavides-Perez, Ricardo; Flores-Favela, Manuel [Servicios Administrativos Penoles S.A de C.V., Torreon, Coahuila (Mexico)

2017-07-15

An experimental study on the phase equilibrium and the liquidus isotherms for the PbO-ZnO-CaO-SiO{sub 2} -“Fe{sub 2}O{sub 3} ” system with CaO/SiO{sub 2} in 1.1 and PbO/(CaO+SiO{sub 2}) in 2.4 weight ratios, respectively, was carried out in the temperature range 1100-1300 deg C (1373-1573 K). High temperature phases were determined by the equilibrium-quenching method. Results are presented in the form of pseudo-ternary sections “Fe{sub 2}O{sub 3} ”-ZnO-(PbO+CaO+SiO{sub 2}). X-Ray diffraction (XRD) and SEM-EDS results showed that the phase equilibria in this system are dominated by the high melting temperature spinel and zincite phases. It was observed that if the system is at a temperature below 1300 deg C and the total (Fe{sub 2}O{sub 3} + ZnO) is greater than 20 wt%, spinel and/or zincite will be present in the slag system. As an application of the phase diagram, the liquid phase compositions below the liquidus surface were estimated, then their viscosities were calculated using FACTSage software. (author)

Cólera en Apartadó, Antioquia: aspectos clínicos y epidemiológicos Cholera in Apartadó, Colombia: clinical and epidemiological aspects

Directory of Open Access Journals (Sweden)

Gustavo A. Uribe Miller

1994-04-01

Full Text Available Este trabajo fue realizado en el Hospital Regional de Apartadó, Antioquia, motivado por la falta de experiencia con cólera en la región y por la similitud clínica y epidemiológica que esta enfermedad presenta con otras enteritis agudas, endémicas en la zona. Los objetivos fueron: analizar algunas variables epidemiológicas y clínicas, verificar la eficacia del tratamiento y comparar el comportamiento del cólera con el de la Enfermedad Diarreica Aguda (EDA sin cólera. Se revisaron las historias clínicas y epidemiológicas de 181 pacientes atendidos entre agosto 11 y octubre 11 de 1991. Se configuró un estudio retrospectivo con las siguientes variables: coprocultivo para Vibrio cholerae, edad, sexo, ocupación, procedencia, estado de hidratación al consultar, duración de la estadía hospitalaria, equilibrio hídrico, asociación epidemio16gica y condiciones sanitarias. Se confirmó cólera por coprocultivo en 87 casos (48%. Al comparar el cólera con la EDA sin cólera, sólo se encontró diferencia significativa en cuanto al grupo de edad afectado (p=O.042 ya la duración de la hospitalización (p=O.O16. El tratamiento recomendado por la OMS fue eficaz según el criterio clínico. No hubo complicaciones ni reingresos; ningún paciente falleció.

One hundred and eighty one patients with acute diarrhea disease (ADD were analyzed from the clinical and epidemiological points of view; 87 of them (48.1% had confirmed cholera while the remaining 94 (51.9% were classified as non-cholera ADD; the only significant differences between these two groups were observed in age and days of hospital stay: cholera predominated In patients older than 5 years (p=O.O42 and the frequency of a hospital stay longer than 2 days was higher in cholera patients (p=O.O16. WHO recommended treatment was effective according to clinical criteria; neither complications nor deaths were found.

Diaqua-2κ2O-bis(μ-1-oxido-2-naphthoato-1:2κ3O1,O2:O2′;2:3κ3O2:O1,O2′-bis(1-oxido-2-naphthoato-1κ1O2,O2;3κ2O1,O2-hexapyridine-1κ2N,2κ2N,3κ2N-trimanganese(II/III pyridine disolvate dihydrate

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Daqi Wang

2008-12-01

Full Text Available The title complex, [Mn3(C11H6O34(C5H5N6(H2O2]·2H2O·2C5H5N, is a trinuclear mixed oxidation state complex of overline1 symmetry. The three Mn atoms are six-coordinated in the shape of distorted octahedra, each coordinated with an O4N2 set of donor atoms, where the ligands exhibit mono- and bidentate modes. However, the coordination of the MnII ion located on the inversion centre involves water molecules at two coordination sites, whereas that of the two symmetry-related MnIII ions involves an O4N2 set of donor atoms orginating from the organic ligands. Intramolecular C—H...π interactions between neighbouring pyridine ligands stabilize this arrangement. A two-dimensional network parallel to (001 is formed by intermolecular O—H...O hydrogen bonds.

Structural, dielectric and magnetic properties of Mn modified xBiFeO{sub 3}-(1−x)BaTiO{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Dai, Zhonghua, E-mail: zhdai@mail.xjtu.edu.cn [College of Mechanics and Materials, Hohai University, Nanjing 210098 (China); Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan); Liu, Lu; Ying, Guobing; Yuan, Ming [College of Mechanics and Materials, Hohai University, Nanjing 210098 (China); Ren, Xiaobing [Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan)

2017-07-15

Manganese doped xBiFeO{sub 3}-(1−x)BaTiO{sub 3}(x=0.67–0.82) ceramics were prepared by solid-state method. The structural, dielectric and magnetic properties were investigated after annealing in vacuum at 773 K. X-ray diffraction analysis indicated that all samples crystallized in pure perovskite structure. The ceramics displays a typical ferroelectric loop, with a max remnant polarization P{sub r} of 25.6 µC/cm{sup 2}. The piezoelectric coefficient d{sub 33} of Manganese doped 0.67BiFeO{sub 3}0.33BaTiO{sub 3} is 139 pC/N and its temperature dependence of dielectric constant exhibits a broad anomaly. The Manganese doped 0.75BiFeO{sub 3}0.25BaTiO{sub 3} ceramic shows ferrimagnetism at room temperature, with remnant magnetization M{sub r} of 0.31 emu/g and ferrimagnetic transition temperature T{sub N} of ~420 °C. - Highlights: • In this manuscript, a technique combined Mn doping which is able to fabricate point defects and annealing in vacuum which can stabilize the unstable ion was investigated. We studied the electrical properties of Mn doped BiFeO{sub 3}-BaTiO{sub 3} ceramics after vacuum annealing treatment at appropriate temperature. • Our result is that Mn modification and heat treatment are effective methods to solve the problem of high leakage of BiFeO{sub 3}-BaTiO{sub 3} system ceramic prepared by solid-state method. It exhibited a enhanced field-induced ferromagnetic ordering with promising potential in spintronics and recording media applications.

{6,6′-Dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne]diphenolato-1κ4O1,O1′,O6,O6′:2κ4O1,N,N′,O1′}(ethanol-1κO-μ-nitrato-1:2κ2O:O′-dinitrato-1κ4O,O′-samarium(IIIzinc(II

Directory of Open Access Journals (Sweden)

Qiang Huang

2009-10-01

Full Text Available In the title heteronuclear ZnII–SmIII complex, [SmZn(C18H18N2O4(NO33(CH3CH2OH], with the hexadentate Schiff base compartmental ligand N,N′-bis(3-methoxysalicylideneethylenediamine (H2L, the SmIII and ZnII ions are triply bridged by two phenolate O atoms from the Schiff base ligand and one nitrate anion. The five-coordinate ZnII ion is in a square-pyramidal geometry formed by the donor centers of two imine N atoms, two phenolate O atoms and one of the bridging nitrate O atoms. The SmIII center is in a ten-fold coordination of O atoms, involving the phenolate O atoms, two methoxy O atoms, one ethanol O atom, and two O atoms from two nitrate anions and one from the bridging nitrate anion. In the crystal, intermolecular O—H...O and C—H...O interactions generate a layer structure extending parallel to (101.

Density functional theory study of the adsorption and dissociation of O{sub 2} on CuO(1 1 1) surface

Energy Technology Data Exchange (ETDEWEB)

Sun, Shujuan, E-mail: sunshujuan@hebut.edu.cn [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Li, Chunyu [Science and Technology Innovation Center, Datang Technologies Industry Group Company Limited, Beijing (China); Zhang, Dongsheng [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Wang, Yanji, E-mail: yjwang@hebut.edu.cn [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China)

2015-04-01

Highlights: • The dissociation mechanisms of O{sub 2} on the CuO(1 1 1) surface have been obtained. • The energy barriers and reaction energies are calculated. • The presence of oxygen vacancy can obviously improve the catalytic activity of CuO. - Abstract: Density functional theory (DFT) have been performed to investigate the adsorption and dissociation of O{sub 2} on the perfect and oxygen-deficient CuO(1 1 1) surfaces. The calculated results indicate that the bridge site of two Cu{sub sub} atoms is the most favorable site for O adsorption on the perfect CuO(1 1 1) surface. But on the oxygen-deficient CuO(1 1 1) surface, the O atom adsorbed on O{sub vacancy} site after optimization. On the perfect and oxygen-deficient CuO(1 1 1) surfaces, the O{sub 2} are all paralleling to the surface after optimization. Possible dissociation pathways of molecularly adsorbed O{sub 2} on the two surfaces are identified. The calculated results suggest that the presence of oxygen vacancy exhibits a strong chemical reactivity towards the dissociation of O{sub 2} and can obviously improve the catalytic activity of CuO.

Poly[[tetraaqua(μ3-naphthalene-1,6-disulfonato-κ4O1:O6,O6′:O6′′strontium(II] monohydrate

Directory of Open Access Journals (Sweden)

Shan Gao

2011-12-01

Full Text Available In the crystal structure of the polymeric title compound, {[Sr(C10H6O6S2(H2O4]·H2O}n, the naphthalene-1,6-disulfonate dianion uses one –SO3 unit to O,O′-chelate to an SrII cation and its third O atom to bind to another SrII cation. The other –SO3 unit binds to yet another SrII atom. The four coordinated water molecules are monodentate but one is disordered over two positions in a 1:1 ratio. The μ3-bonding mode of the dianion generates a polymeric three-dimensional network; the network is consolidated by O—H...O hydrogen bonds. The SrII cation exists in an undefined eight-coordinate environment.

Electric Properties of Pb(Sb1/2Nb1/2)O3 PbTiO3 PbZrO3 Ceramics

Science.gov (United States)

Kawamura, Yasushi; Ohuchi, Hiromu

1994-09-01

Solid-solution ceramics of ternary system xPb(Sb1/2Nb1/2)O3 yPbTiO3 zPbZrO3 were prepared by the solid-state reaction of powder materials. Ceramic, electric, dielectric and piezoelectric properties and crystal structures of the system were studied. Sintering of the system xPb(Sb1/2Nb1/2)O3 yPbTiO3 zPbZrO3 is much easier than that of each end composition, and well-sintered high-density ceramics were obtained for the compositions near the morphotropic transformation. Piezoelectric ceramics with high relative dielectric constants, high radial coupling coefficient and low resonant resistance were obtained for the composition near the morphotropic transformation. The composition Pb(Sb1/2Nb1/2)0.075Ti0.45Zr0.475O3 showed the highest dielectric constant (ɛr=1690), and the composition Pb(Sb1/2Nb1/2)0.05Ti0.45Zr0.5O3 showed the highest radial coupling coefficient (kp=64%).

Crystallization behavior of (1 - x)Li2O.xNa2O.Al2O3.4SiO2 glasses

International Nuclear Information System (INIS)

Wang, Moo-Chin; Cheng, Chih-Wei; Chang, Kuo-Ming; Hsi, Chi-Shiung

2010-01-01

The crystallization behavior of the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED) and energy dispersive spectroscopy (EDS). The crystalline phase was composed of β-spodumene. The isothermal crystallization kinetics of β-spodumene from the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses has also been studied by a quantitative X-ray diffraction method. The activation energy of β-spodumene formation decreases from 359.2 to 317.8 kJ/mol when the Na 2 O content increases from 0 to 0.4 mol and it increases from 317.8 to 376.9 kJ/mol when the Na 2 O content increases from 0.4 to 0.6 mol. The surface nucleation and plate-like growth were dominant in the crystallization of the (1 - x)Li 2 O.xNa 2 O.Al 2 O 3 .4SiO 2 glasses.

Cholera returns to southern Vietnam in an outbreak associated with consuming unsafe water through iced tea: A matched case-control study.

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Nguyen, Thuong V; Pham, Quang D; Do, Quoc K; Diep, Tai T; Phan, Hung C; Ho, Thang V; Do, Hong T; Phan, Lan T; Tran, Huu N

2017-04-01

After more than a decade of steadily declining notifications, the number of reported cholera cases has recently increased in Vietnam. We conducted a matched case-control study to investigate transmission of cholera during an outbreak in Ben Tre, southern Vietnam, and to explore the associated risk factors. Sixty of 71 diarrheal patients confirmed to be infected with cholera by culture and diagnosed between May 9 and August 3, 2010 in Ben Tre were consecutively recruited as case-patients. Case-patients were matched 1:4 to controls by commune, sex, and 5-year age group. Risk factors for cholera were examined by multivariable conditional logistic regression. In addition, environmental samples from villages containing case-patients were taken to identify contamination of food and water sources. The regression indicated that drinking iced tea (adjusted odds ratio (aOR) = 8.40, 95% confidence interval (CI): 1.84-39.25), not always boiling drinking water (aOR = 2.62, 95% CI: 1.03-6.67), having the main source of water for use being close to a toilet (aOR = 4.36, 95% CI: 1.37-13.88), living with people who had acute diarrhea (aOR = 13.72, 95% CI: 2.77-67.97), and little or no education (aOR = 4.89, 95% CI: 1.18-20.19) were significantly associated with increased risk of cholera. In contrast, drinking stored rainwater (aOR = 0.17, 95% CI: 0.04-0.63), eating cooked seafood (aOR = 0.27, 95% CI: 0.10-0.73), and eating steamed vegetables (aOR = 0.22, 95% CI: 0.07-0.70) were protective against cholera. Vibrio cholerae O1 Ogawa carrying ctxA was found in two of twenty-five river water samples and one of six wastewater samples. The magnitude of the cholera outbreak in Ben Tre was lower than in other similar settings. This investigation identified several risk factors and underscored the importance of continued responses targeting cholera prevention in southern Vietnam. The association between drinking iced tea and cholera and the spread of V. cholerae O1, altered El Tor strains

Cholera returns to southern Vietnam in an outbreak associated with consuming unsafe water through iced tea: A matched case-control study.

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Thuong V Nguyen

2017-04-01

Full Text Available After more than a decade of steadily declining notifications, the number of reported cholera cases has recently increased in Vietnam. We conducted a matched case-control study to investigate transmission of cholera during an outbreak in Ben Tre, southern Vietnam, and to explore the associated risk factors.Sixty of 71 diarrheal patients confirmed to be infected with cholera by culture and diagnosed between May 9 and August 3, 2010 in Ben Tre were consecutively recruited as case-patients. Case-patients were matched 1:4 to controls by commune, sex, and 5-year age group. Risk factors for cholera were examined by multivariable conditional logistic regression. In addition, environmental samples from villages containing case-patients were taken to identify contamination of food and water sources. The regression indicated that drinking iced tea (adjusted odds ratio (aOR = 8.40, 95% confidence interval (CI: 1.84-39.25, not always boiling drinking water (aOR = 2.62, 95% CI: 1.03-6.67, having the main source of water for use being close to a toilet (aOR = 4.36, 95% CI: 1.37-13.88, living with people who had acute diarrhea (aOR = 13.72, 95% CI: 2.77-67.97, and little or no education (aOR = 4.89, 95% CI: 1.18-20.19 were significantly associated with increased risk of cholera. In contrast, drinking stored rainwater (aOR = 0.17, 95% CI: 0.04-0.63, eating cooked seafood (aOR = 0.27, 95% CI: 0.10-0.73, and eating steamed vegetables (aOR = 0.22, 95% CI: 0.07-0.70 were protective against cholera. Vibrio cholerae O1 Ogawa carrying ctxA was found in two of twenty-five river water samples and one of six wastewater samples.The magnitude of the cholera outbreak in Ben Tre was lower than in other similar settings. This investigation identified several risk factors and underscored the importance of continued responses targeting cholera prevention in southern Vietnam. The association between drinking iced tea and cholera and the spread of V. cholerae O1, altered El Tor

Cholera between 1991 and 1997 in Mexico was associated with infection by classical, El Tor, and El Tor variants of Vibrio cholerae.

Science.gov (United States)

Alam, Munirul; Nusrin, Suraia; Islam, Atiqul; Bhuiyan, Nurul A; Rahim, Niaz; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Gil, Ana I; Watanabe, Haruo; Morita, Masatomo; Nair, G Balakrish; Cravioto, Alejandro

2010-10-01

Vibrio cholerae O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of V. cholerae causing endemic cholera in Latin America is lacking. The present retrospective microbiological, molecular, and phylogenetic study of V. cholerae isolates recovered in Mexico (n = 91; 1983 to 1997) shows the existence of the pre-1991 CL biotype and the ET and CL biotypes together with the altered ET biotype in both epidemic and endemic cholera between 1991 and 1997. According to sero- and biotyping data, the altered ET, which has shown predominance in Mexico since 1991, emerged locally from ET and CL progenitors that were found coexisting until 1997. In Latin America, ET and CL variants shared a variable number of phenotypic markers, while the altered ET strains had genes encoding the CL CTX (CTX(CL)) prophage, ctxB(CL) and rstR(CL), in addition to resident rstR(ET), as the underlying regional signature. The distinct regional fingerprints for ET in Mexico and Peru and their divergence from ET in Asia and Africa, as confirmed by subclustering patterns in a pulsed-field gel electrophoresis (NotI)-based dendrogram, suggest that the Mexico epidemic in 1991 may have been a local event and not an extension of the epidemics occurring in Asia and South America. Finally, the CL biotype reservoir in Mexico is unprecedented and must have contributed to the changing epidemiology of global cholera in ways that need to be understood.

Synthesis of 1-primary alkylamino-o-carboranes by reduction of 1-primary alkylnitro-o-carboranes

International Nuclear Information System (INIS)

Zakharkin, L.I.; Ol'shevskaya, V.A.; Vinogradova, L.E.

1999-01-01

By action of 1-sodium-o-carboranes in liquid ammonia on α,β-unsaturated nitro compounds an easy addition of 1-sodium-o-carboranes to 1-4 positions of α,β-unsaturated nitro compounds is observed resulting in o-carborane nitro derivatives. Primary alkylamino-o-carboranes isolated as a hydrochlorides have been prepared by reducing some o-carborane nitro derivatives with LiAlH 4 in ether solutions [ru

(2-Formyl-6-methoxyphenolato-κ2O1,O2(perchlorato-κO(1,10-phenanthroline-κ2N,N′copper(II

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Zhi-Yong Wu

2008-05-01

Full Text Available In the title molecule, [Cu(C8H7O3(ClO4(C12H8N2], the CuII ion is five-coordinated by two N atoms [Cu—N = 1.995 (3 and 2.022 (3 Å] from a 1,10-phenanthroline ligand, two O atoms [Cu—O = 1.908 (2 and 1.927 (2 Å] from an o-vanillin ligand and one O atom [Cu—O = 2.510 (3 Å] from a perchlorate anion in a distorted square-pyramidal geometry. Three O atoms of the perchlorate anion are rotationally disordered between two orientations, with occupancies of 0.525 (13 and 0.475 (13. In the crystal structure, two molecules related by a centre of symmetry are paired in such a way that the phenolate O atom from one molecule completes the distorted octahedral Cu coordination in another molecule [Cu...O = 2.704 (2 Å].

[The role of food in cholera transmission].

Science.gov (United States)

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

1995-01-01

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

Vibrio cholerae classical biotype strains reveal distinct signatures in Mexico.

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Alam, Munirul; Islam, M Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R; Cravioto, Alejandro

2012-07-01

Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 1991 and 1997. In this study, CL biotype strains isolated from areas of cholera endemicity in Mexico between 1983 and 1997 were characterized in terms of major phenotypic and genetic traits and compared with CL biotype strains isolated in Bangladesh between 1962 and 1989. According to sero- and biotyping data, all V. cholerae strains tested had the major phenotypic and genotypic characteristics specific for the CL biotype. Antibiograms revealed the majority of the Bangladeshi strains to be resistant to trimethoprim-sulfamethoxazole, furazolidone, ampicillin, and gentamicin, while the Mexican strains were sensitive to all of these drugs, as well as to ciprofloxacin, erythromycin, and tetracycline. Pulsed-field gel electrophoresis (PFGE) of NotI-digested genomic DNA revealed characteristic banding patterns for all of the CL biotype strains although the Mexican strains differed from the Bangladeshi strains in 1 to 2 DNA bands. The difference was subtle but consistent, as confirmed by the subclustering patterns in the PFGE-based dendrogram, and can serve as a regional signature, suggesting the pre-1991 existence and evolution of the CL biotype strains in the Americas, independent from Asia.

Phosphide oxides RE2AuP2O (RE = La, Ce, Pr, Nd): synthesis, structure, chemical bonding, magnetism, and 31P and 139La solid state NMR.

Science.gov (United States)

Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer

2013-02-18

Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

Associação entre dois diferentes tipos de estrangulamento com a variação da pressão intraocular em atletas de jiu-jitsu Association between two different types of strangling and intraocular pressure variation in jiu-jitsu athletes

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Marinho Jorge Scarpi

2009-06-01

Full Text Available OBJETIVO: Verificar a associação entre dois diferentes tipos de estrangulamento com a variação da pressão intraocular em atletas de jiu-jitsu. MÉTODO: Estudo observacional em grupo de 9 atletas de jiu-jitsu, com mínimo 6 meses de treinamento, sexo masculino, idades entre 20 e 30 anos, sem presença de lesões físicas e do bulbo ocular. Buscou-se associação entre a variação da pressão intraocular e os estrangulamentos Frontal da Guarda (E1 e Frontal da Montada (E2. A pressão intraocular foi determinada com o tonômetro de Perkins, inicialmente sem que o atleta tivesse realizado atividade física nas 24 horas antecedentes e após cada golpe. Realizou-se medidas da pressão intraocular por 12 minutos, uma a cada 3 minutos de recuperação (R1; R2; R3; R4, com o indivíduo deitado. Como procedimento estatístico foi empregado o teste ANOVA e o pós-teste de Bonferroni. RESULTADOS: Ocorreu redução significativa da pressão intraocular em ambos os olhos durante a situação E2 comparada a E1 em todos os momentos da aferição de recuperação: R1 (OD: 8,22 ± 1,39 vs.11,33 ± 2,00 / OE: 8,55 ± 1,23 vs. 11,88 ± 1,90, R2 (OD: 8,44 ± 1,87 vs.10,22 ± 2,53 / OE: 9,00 ± 1,80 vs. 10,44 ± 2,35, R3 (OD: 8,44 ± 1,74 vs.9,78 ± 2,54 / OE: 8,55 + 1,42 vs. 10,33 ± 1,93 todos com pPURPOSE: To verify the association between two different types of strangling with intraocular pressure variation in jiu-jitsu athletes. METHODS: An observational study was performed on 9 athletes of jiu-jitsu, with at least 6 month of training, male, aged 20 to 30 years, without any physical and eyeball lesions. Associations between intraocular pressure and Cross Choke from the guard strangling (E1, and E2 - Cross Choke from mount strangling were gotten. Intraocular pressure was determined by using Perkins tonometer, at first in the absence of physical exercise over the last 24 hours and after each strangling. Then it was carried out the intraocular pressure

The vibration-rotation-tunneling levels of N2-H2O and N2-D2O

Science.gov (United States)

Wang, Xiao-Gang; Carrington, Tucker

2015-07-01

In this paper, we report vibration-rotation-tunneling levels of the van der Waals clusters N2-H2O and N2-D2O computed from an ab initio potential energy surface. The only dynamical approximation is that the monomers are rigid. We use a symmetry adapted Lanczos algorithm and an uncoupled product basis set. The pattern of the cluster's levels is complicated by splittings caused by H-H exchange tunneling (larger splitting) and N-N exchange tunneling (smaller splitting). An interesting result that emerges from our calculation is that whereas in N2-H2O, the symmetric H-H tunnelling state is below the anti-symmetric H-H tunnelling state for both K = 0 and K = 1, the order is reversed in N2-D2O for K = 1. The only experimental splitting measurements are the D-D exchange tunneling splittings reported by Zhu et al. [J. Chem. Phys. 139, 214309 (2013)] for N2-D2O in the v2 = 1 region of D2O. Due to the inverted order of the split levels, they measure the sum of the K = 0 and K = 1 tunneling splittings, which is in excellent agreement with our calculated result. Other splittings we predict, in particular those of N2-H2O, may guide future experiments.

139La NMR evidence for sensitivity of local structure to magnetic field in La0.5Ca0.5MnO3

International Nuclear Information System (INIS)

Yoshinari, Y.; Hammel, P.C.; Thompson, J.D.; Cheong, S.

1999-01-01

We report 139 La nuclear-magnetic-resonance measurements on La 0.5 Ca 0.5 MnO 3 . Two resonance peaks observed in zero applied field are identified as ferromagnetic (FM) resonances arising from FM domains with eight nearest Mn moments almost fully polarized. The two La sites are distinguished by experiencing different covalent configurations with respect to the nearest Mn ions, likely caused by the charge/orbital ordering. The two sites collapse into one in the presence of a strong magnetic field, indicating the close relationship between magnetism and the lattice deformation. copyright 1999 The American Physical Society

The burden of diarrhoea, shigellosis, and cholera in North Jakarta, Indonesia: findings from 24 months surveillance

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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.

Synthesis and Molecular Structure of the 5-Methoxycarbonylpentyl α-Glycoside of the Upstream, Terminal Moiety of the O-Specific Polysaccharide of Vibrio cholerae O1, Serotype Inaba

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Peng Xu

2015-02-01

Full Text Available The trimethylsilyl trifluoromethanesulfonate (TMSOTf-catalyzed reaction of methyl 6-hydroxyhexanoate with 3-O-benzyl-4-(2,4-di-O-acetyl-3-deoxy-L-glycero-tetronamido-4,6-dideoxy-2-O-levulinoyl-α-d-mannopyranosyl trichloroacetimidate followed by a two-step deprotection (hydrogenolysis over Pd/C catalyst and Zemplén deacylation, to simultaneously remove the acetyl and levulinoyl groups gave 5-(methoxycarbonylpentyl 4-(3-deoxy-L-glycero-tetronamido-4,6-dideoxy-α-D-mannopyranoside. The structure of the latter, for which crystals were obtained in the analytically pure state for the first time, followed from its NMR and high-resolution mass spectra and was confirmed by X-ray crystallography. The molecule has two approximately linear components; a line through the aglycon intersects a line through the mannosyl and tetronylamido groups at 120°. The crystal packing separates the aglycon groups from the tetronylamido and mannosyl groups, with only C-H…O hydrogen bonding among the aglycon groups and N-H…O, O-H…O and C-H…O links among the tetronylamido and mannosyl groups. A carbonyl oxygen atom accepts the strongest O-H…O hydrogen bond and two strong C-H…O hydrogen bonds. The geometric properties were compared with those of related molecules.

[GM1-dot-EIA for the detection of toxin-producing Vibrio cholerae strains].

Science.gov (United States)

Markina, O V; Alekseeva, L P; Telesmanich, N R; Chemisova, O S; Akulova, M V; Markin, N V

2011-05-01

A new variant of enzyme immunoassay (EIA) has been developed on the basis of GM1 gangliosides to detect the toxin-producing Vibrio cholerae strains--GM1-dot-EIA. Experiments were run using a nitrocellulose membrane to bind GM1 gangliosides and polyclonal antitoxic serum to detect cholerogen. GM1-dot-EIA testing identified cholera toxin in 11 of 13 supernatants of V. cholerae eltor ctx(+) strains isolated from man and in 3 of 7 supernatants of V. cholerae eltor ctx(+) strains isolated from water. These data agree with those obtained in CM1-EIA. There was no reaction with the supernatants of other microorganisms. The sensitivity of the technique was 10 ng/ml. Thus, the simple and specific GM1-dot-EIA may be recommended to detect toxin-producing V cholerae strains isolated from man and water.

Inactivation of Vibrio cholerae O1 El Tor inoculated into Peruvian ''choro'' mussels (Aulacomya ater) and two species of clams (Argopecten purpuratus and Gari solida) using medium-dose irradiation

International Nuclear Information System (INIS)

Torres, Z.; Bernuy, B.; Kahn, G.; Zapata, G.; Vivanco, M.; Guzman, E.; Leon, R.

2001-01-01

The radiation decimal reduction dose (D 10 ) for Vibrio cholerae O1 biotype El Tor inoculated through the natural feeding system into three species of bivalve mollusks from the Peruvian Pacific coast: ''choro'' mussels (Aulacome ater), ''abanico'' clams (Argopecten purpuratus), and common clams (Gari solida), was determined in vivo. The D 10 value obtained in vivo was 0.14 kGy in all mollusks tested. Concurrent studies conducted to determine the potential use of irradiation to extend the microbiological shelf-life of the mollusks during post-irradiation storage at 0-1 deg. C indicated that a dose of 1.0 kGy was optimal for choro mussels and abanico clams, whereas 2.0 kGy produced the best results when treating common clams. Shelf-life extension thus achieved was 31 days for choro mussels, 16 days for abanico clams, and 21 days for common clams. Non-irradiated control samples of all mollusks spoiled after 17 days of refrigerated storage. There were no significant (p<.05) adverse effects from the application of the optimal radiation treatments on the sensory characteristics (i.e. appearance, odor, flavor, and texture) of the mollusks. Total volatile basic nitrogen (VBN) and pH values were examined for use as indexes of seafood freshness. (author)

208Pb(16O,15O)209Pb reaction

International Nuclear Information System (INIS)

Becchetti, F.D.; Harvey, B.G.; Kovar, D.; Mahoney, J.; Maguire, C.; Scott, D.K.

1975-01-01

The neutron levels in 209 Pb have been studied with the 208 Pb( 16 O, 15 O) reaction at a bomdarding energy of 139 MeV. Spectroscopic factors (S) have been deduced using a finite-range distorted-wave Born approximation (DWBA) with recoil. The 2g 9 / 2 , 1i 11 / 2 , 2g 7 / 2 , and 3d 3 / 2 levels are found to have S approximately-greater-than 0.9 while S approx. = 0.7 for the 1j 15 / 2 level at 1.4 MeV excitation. Evidence is found for other 1j 15 / 2 fragments being at 3.05 MeV and approx. 3.8 MeV with S approx. = 0.08 and 0.26, respectively, which would place the centroid of the 1j 15 / 2 level at E/subx/ approx. = 2.2 MeV. DWBA predicts a shift in the maxima of the angular distributions as a function of Q value which is not observed experimentally. A comparison with the proton transfer reaction 208 Pb( 16 O, 15 N) 209 Bi has been used to deduce the geometrical parameters of a neutron shell model potential appropriate for nuclei with A approximately-greater-than 200. The parameters of this Wood-Saxon potential are: V/subR/=-50.5 MeV,r/subR/=1.19 fm, a/subR/=0.75 fm, V)=-5.5 MeV, r)=1.01 fm, and a)=0.75 fm

Situação vacinal da população discente da Universidade de São Paulo Vaccinal condition of the student population of the S. Paulo University

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Ernesto Lima Gonçalves

1977-06-01

Full Text Available São apresentados aspectos da situação vacinal dos alunos dos Institutos da Universidade de São Paulo, situados na capital e nos "campi" do interior em Ribeirão Preto, São Carlos, Bauru e Piracicaba, Estado de São Paulo, Brasil. Foi realizado inquérito preliminar mediante a aplicação de questionário especial a uma amostra de 13.139 alunos (42,3% do total de matriculados, sendo 1.707 alunos no interior (38,3% dos matriculados e 11.432 na capital (43% dos matriculados. Os principais dados sobre vacinação antivariólica foram: 20% dos alunos do interior e 30% dos da capital informaram não ter a cicatriz ou não saber de sua existência; 50% dos alunos do interior e 75% dos da capital informaram ter sido vacinados há menos de 5 anos; 35% do total de alunos afirmaram que o resultado da última vacina recebida foi positivo. Não foram vacinados contra o tétano ou não receberam a vacina de acordo com o esquema preconizado pela Secretaria de Estado da Saúde, 2/3 dos alunos. Os dados sobre vacinação antimeningocócica revelaram que 17% dos alunos do interior e 80% dos da capital declaravam ter sido vacinados. Foram examinados 3.113 estudantes, definindo-se pela vacinação antivariólica de 405 deles (13% do total; destes, 253 (62,5% retornaram para leitura, que foi positiva em 221 (87,3 deles. Em relação à vacina antitetânica, 1 .118 alunos da USP receberam as duas doses programadas, o que dá um índice de 66,9%; considerados separadamente os alunos de graduação e de pós-graduação, esse índice foi respectivamente de 66,1% e 80,2%.Some aspects regarding the vaccinal situation of students in the various "campi" of the São Paulo University (USP are presented. At first an inquest was made, by means of a questionnaire which was answered by 13.139 people (42.3% of the total university population. With respect to amallpox immunization, 20% of pupils from upcountry and 30% from São Paulo said they had no vaccination scar; 50% of

Coliform and Vibrio cholerae Analysis of Drinking Water Collected from Cholera Outbreak Region of Bhaktapur Municipality

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Upendra Thapa Shrestha

2014-09-01

Full Text Available Water borne infections in Nepal, especially in Kathmandu valley is one the major public health problems, causing thousands of deaths every year. Among three cities in the valley, the water borne infection including cholera is most predominant in Bhaktapur district. So the study was carried out to know the microbial drinking water quality in the city and to determine the prevalence of water borne infections in the specified region of the district in 2012. Altogether eighty (two samples from a single site at different interval-2/3 days water samples were collected from Bhaktapur Municipality, one of the most vulnerable regions for water borne diseases, following standard methods as described by APHA, 2010. All samples were transferred to Microbiology laboratory of Khwopa College, Dekocha, Bhaktapur and preceded immediately for Microbial analysis. The coliform density in the water samples were determined by Most Probable Number (MPN method followed by microscopy, colonial morphology and biochemical characterization. Subsequently, the presence of Vibrio cholerae, a causative agent of Cholera was analyzed in the same samples by enrichment in alkaline peptone water followed by culture on Thiosulphate citrate bile-salt sucrose (TCBS agar, a selective media for Vibrio spp. The biochemical tests were then performed to identify V. cholerae. Among eighty water samples, 87.5 percent water samples contained coliforms and half of which (45% contained feacal coliforms, Escherichia coli and remaining 12.5 percent water samples contained no coliforms. Vibrio cholerae were isolated from four water samples (5%. The drinking water quality in the region was found to be very poor. Therefore, the people in the region were suggested to treat the drinking water by using any of physical or chemical disinfection methods prior to drinking. DOI: http://dx.doi.org/10.3126/ije.v3i3.11073 International Journal of Environment Vol.3(3 2014: 139-145

Antibody Secreting Cell Responses following Vaccination with Bivalent Oral Cholera Vaccine among Haitian Adults.

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Wilfredo R Matias

2016-06-01

Full Text Available The bivalent whole-cell (BivWC oral cholera vaccine (Shanchol is effective in preventing cholera. However, evaluations of immune responses following vaccination with BivWC have been limited. To determine whether BivWC induces significant mucosal immune responses, we measured V. cholerae O1 antigen-specific antibody secreting cell (ASC responses following vaccination.We enrolled 24 Haitian adults in this study, and administered doses of oral BivWC vaccine 14 days apart (day 0 and day 14. We drew blood at baseline, and 7 days following each vaccine dose (day 7 and 21. Peripheral blood mononuclear cells (PBMCs were isolated, and ASCs were enumerated using an ELISPOT assay. Significant increases in Ogawa (6.9 cells per million PBMCs and Inaba (9.5 cells per million PBMCs OSP-specific IgA ASCs were detected 7 days following the first dose (P < 0.001, but not the second dose. The magnitude of V. cholerae-specific ASC responses did not appear to be associated with recent exposure to cholera. ASC responses measured against the whole lipolysaccharide (LPS antigen and the OSP moiety of LPS were equivalent, suggesting that all or nearly all of the LPS response targets the OSP moiety.Immunization with the BivWC oral cholera vaccine induced ASC responses among a cohort of healthy adults in Haiti after a single dose. The second dose of vaccine resulted in minimal ASC responses over baseline, suggesting that the current dosing schedule may not be optimal for boosting mucosal immune responses to V. cholerae antigens for adults in a cholera-endemic area.

Synthesis of 1-D ZnO nanorods and polypyrrole/1-D ZnO ...

Indian Academy of Sciences (India)

1-D ZnO nanorods and PPy/1-D ZnO nanocomposites were prepared by the surfactant-assisted precipitation and in situ polymerization method, respectively. The synthesized nanorods and nanocomposites were characterized by UV–Vis spectrophotometer, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction ...

DISCOVERY OF MAIN-BELT COMET P/2006 VW{sub 139} BY Pan-STARRS1

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Henry H.; Yang Bin; Haghighipour, Nader; Kaluna, Heather M.; Denneau, Larry; Jedicke, Robert; Wainscoat, Richard J.; Armstrong, James D.; Micheli, Marco; Keane, Jacqueline V.; Urban, Laurie; Riesen, Timm; Meech, Karen J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fitzsimmons, Alan [Astrophysics Research Centre, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Novakovic, Bojan [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Duddy, Samuel R.; Lowry, Stephen C. [Centre for Astrophysics and Planetary Science, The University of Kent, Canterbury CT2 7NH (United Kingdom); Trujillo, Chadwick A. [Gemini Observatory, Northern Operations Center, 670 N. Aohoku Place, Hilo, HI 96720 (United States); Abe, Shinsuke; Cheng, Yu-Chi, E-mail: hsieh@ifa.hawaii.edu [Institute of Astronomy, National Central University, 300 Jhongda Rd, Jhongli 32001, Taiwan (China); and others

2012-03-20

The main-belt asteroid (300163) 2006 VW{sub 139} (later designated P/2006 VW{sub 139}) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short ({approx}10'') antisolar dust tail and a longer ({approx}60'') dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event. Photometry showing the brightness of the near-nucleus coma remaining constant over {approx}30 days provides further evidence for this object's cometary nature, suggesting it is in fact an MBC, and not a disrupted asteroid. A spectroscopic search for CN emission was unsuccessful, though we find an upper limit CN production rate of Q{sub CN} < 1.3 Multiplication-Sign 10{sup 24} mol s{sup -1}, from which we infer a water production rate of Q{sub H{sub 2O}}<10{sup 26} mol s{sup -1}. We also find an approximately linear optical spectral slope of 7.2%/1000 A, similar to other cometary dust comae. Numerical simulations indicate that P/2006 VW{sub 139} is dynamically stable for >100 Myr, while a search for a potential asteroid family around the object reveals a cluster of 24 asteroids within a cutoff distance of 68 m s{sup -1}. At 70 m s{sup -1}, this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.

[Phylogenetic analysis of genomes of Vibrio cholerae strains isolated on the territory of Rostov region].

Science.gov (United States)

Kuleshov, K V; Markelov, M L; Dedkov, V G; Vodop'ianov, A S; Kermanov, A V; Pisanov, R V; Kruglikov, V D; Mazrukho, A B; Maleev, V V; Shipulin, G A

2013-01-01

Determination of origin of 2 Vibrio cholerae strains isolated on the territory of Rostov region by using full genome sequencing data. Toxigenic strain 2011 EL- 301 V. cholerae 01 El Tor Inaba No. 301 (ctxAB+, tcpA+) and nontoxigenic strain V. cholerae O1 Ogawa P- 18785 (ctxAB-, tcpA+) were studied. Sequencing was carried out on the MiSeq platform. Phylogenetic analysis of the genomes obtained was carried out based on comparison of conservative part of the studied and 54 previously sequenced genomes. 2011EL-301 strain genome was presented by 164 contigs with an average coverage of 100, N50 parameter was 132 kb, for strain P- 18785 - 159 contigs with a coverage of69, N50 - 83 kb. The contigs obtained for strain 2011 EL-301 were deposited in DDBJ/EMBL/GenBank databases with access code AJFN02000000, for strain P-18785 - ANHS00000000. 716 protein-coding orthologous genes were detected. Based on phylogenetic analysis strain P- 18785 belongs to PG-1 subgroup (a group of predecessor strains of the 7th pandemic). Strain 2011EL-301 belongs to groups of strains of the 7th pandemic and is included into the cluster with later isolates that are associated with cases of cholera in South Africa and cases of import of cholera to the USA from Pakistan. The data obtained allows to establish phylogenetic connections with V cholerae strains isolated earlier.

Isolation of Vibrio cholera El Tor Inaba From Lemna minor and Eichhornia crassipens Roots in Veracruz, Mexico

Science.gov (United States)

Cordoba Aguilar, Edgar; Herrera Rivero, Marisol; Rubi, Alberto; Arroyo-Helguera, Omar; Coutino Rodriguez, Rocio

2014-01-01

Background: During epidemic periods, the strain Vibrio cholera El Tor has been isolated from the aquatic macrophyte roots of Eichhornia crassipens and Lemna minor, suggesting that aquatic plants could be environmental reservoirs through either a non-specific association or a commensalism relationship. Therefore, it is important to understand V. cholera reservoirs in order to establish prevention strategies against this pathogen. Objectives: Our interest was to determine whether V. cholera could be isolated and typified from L. minor and E. crassipens roots. Materials and Methods: From 2004 to 2005, plants were collected from various ecological niches and the roots were used to isolate V. cholera. Standard bacteriological, biochemical and serological tests were used for its typification. Results: In five out of the nine ecological niches explored, we collected either L. minor or E. crassipens, as these specimens cohabited only in two niches. V. cholera was isolated from both L. minor and E. crassipens roots. The isolated V. cholera showed the same biochemical characteristics as the pure V. cholera strain which was used as a control. The isolated V. cholera corresponded to V. cholera O1 El Tor Inaba, which is the same serotype related to the last outbreak in Mexico. Conclusions: For first time V. cholera El Tor Inaba has been isolated several years after the last emergence of cholera in Mexico. A viable and cultivable V. cholera strain, sourced from freshwater niches in E. crassipens and L. minor roots, suggests the importance of these plants as a permanent aquatic reservoir for these organisms. The monitoring of E. crassipens and L. minor is the responsibility of health institutions in order to evaluate the ongoing risks. PMID:25147681

Isolation of Vibrio cholera El Tor Inaba From Lemna minor and Eichhornia crassipens Roots in Veracruz, Mexico.

Science.gov (United States)

Cordoba Aguilar, Edgar; Herrera Rivero, Marisol; Rubi, Alberto; Arroyo-Helguera, Omar; Coutino Rodriguez, Rocio

2014-03-01

During epidemic periods, the strain Vibrio cholera El Tor has been isolated from the aquatic macrophyte roots of Eichhornia crassipens and Lemna minor, suggesting that aquatic plants could be environmental reservoirs through either a non-specific association or a commensalism relationship. Therefore, it is important to understand V. cholera reservoirs in order to establish prevention strategies against this pathogen. Our interest was to determine whether V. cholera could be isolated and typified from L. minor and E. crassipens roots. From 2004 to 2005, plants were collected from various ecological niches and the roots were used to isolate V. cholera. Standard bacteriological, biochemical and serological tests were used for its typification. In five out of the nine ecological niches explored, we collected either L. minor or E. crassipens, as these specimens cohabited only in two niches. V. cholera was isolated from both L. minor and E. crassipens roots. The isolated V. cholera showed the same biochemical characteristics as the pure V. cholera strain which was used as a control. The isolated V. cholera corresponded to V. cholera O1 El Tor Inaba, which is the same serotype related to the last outbreak in Mexico. For first time V. cholera El Tor Inaba has been isolated several years after the last emergence of cholera in Mexico. A viable and cultivable V. cholera strain, sourced from freshwater niches in E. crassipens and L. minor roots, suggests the importance of these plants as a permanent aquatic reservoir for these organisms. The monitoring of E. crassipens and L. minor is the responsibility of health institutions in order to evaluate the ongoing risks.

Regulatory O-GlcNAcylation sites on FoxO1 are yet to be identified

Energy Technology Data Exchange (ETDEWEB)

Fardini, Yann [INSERM, U1016, Institut Cochin, Paris (France); CNRS, UMR8104, Paris (France); Université Paris Descartes, Sorbonne Paris Cité, Paris (France); Perez-Cervera, Yobana [Structural and Functional Glycobiology Unit, Lille 1 University, CNRS (UMR 8576), IFR 117, Villeneuve d' Ascq (France); Facultad de Odontología, Universidad Autónoma Benito Juárez de Oaxaca, Oaxaca (Mexico); Camoin, Luc [INSERM, U1068, CRCM, Marseille Protéomique IBiSA, Marseille, F-13009 (France); Institut Paoli-Calmettes Team, Cell Polarity, Cell Signaling and Cancer, Marseille, F-13009 (France); Aix-Marseille Université, F-13284, Marseille (France); CNRS, UMR7258, CRCM, Marseille, F-13009 (France); Pagesy, Patrick [INSERM, U1016, Institut Cochin, Paris (France); CNRS, UMR8104, Paris (France); Université Paris Descartes, Sorbonne Paris Cité, Paris (France); Lefebvre, Tony [Structural and Functional Glycobiology Unit, Lille 1 University, CNRS (UMR 8576), IFR 117, Villeneuve d' Ascq (France); Issad, Tarik, E-mail: tarik.issad@inserm.fr [INSERM, U1016, Institut Cochin, Paris (France); CNRS, UMR8104, Paris (France); Université Paris Descartes, Sorbonne Paris Cité, Paris (France)

2015-06-26

O-GlcNAcylation is a reversible post-translational modification that regulates cytosolic and nuclear proteins. We and others previously demonstrated that FoxO1 is O-GlcNAcylated in different cell types, resulting in an increase in its transcriptional activity. Four O-GlcNAcylation sites were identified in human FOXO1 but directed mutagenesis of each site individually had modest (T317) or no effect (S550, T648, S654) on its O-GlcNAcylation status and transcriptional activity. Moreover, the consequences of mutating all four sites had not been investigated. In the present work, we mutated these sites in the mouse Foxo1 and found that mutation of all four sites did not decrease Foxo1 O-GlcNAcylation status and transcriptional activity, and would even tend to increase them. In an attempt to identify other O-GlcNAcylation sites, we immunoprecipitated wild-type O-GlcNAcylated Foxo1 and analysed the tryptic digest peptides by mass spectrometry using High-energy Collisional Dissociation. We identified T646 as a new O-GlcNAcylation site on Foxo1. However, site directed mutagenesis of this site individually or together with all four previously identified residues did not impair Foxo1 O-GlcNAcylation and transcriptional activity. These results suggest that residues important for the control of Foxo1 activity by O-GlcNAcylation still remain to be identified. - Highlights: • We mutate four previously identified O-GlcNAcylation sites on Foxo1. • Unexpectedly, these mutations do not reduce Foxo1 O-GlcNAcylation. • These mutation do not reduce Foxo1 transcriptional activity. • We identify a new O-GlcNAcylation site on Foxo1 by mass spectrometry. • Mutation of this site increases Foxo1 transcriptional activity.

Regulatory O-GlcNAcylation sites on FoxO1 are yet to be identified

International Nuclear Information System (INIS)

Fardini, Yann; Perez-Cervera, Yobana; Camoin, Luc; Pagesy, Patrick; Lefebvre, Tony; Issad, Tarik

2015-01-01

O-GlcNAcylation is a reversible post-translational modification that regulates cytosolic and nuclear proteins. We and others previously demonstrated that FoxO1 is O-GlcNAcylated in different cell types, resulting in an increase in its transcriptional activity. Four O-GlcNAcylation sites were identified in human FOXO1 but directed mutagenesis of each site individually had modest (T317) or no effect (S550, T648, S654) on its O-GlcNAcylation status and transcriptional activity. Moreover, the consequences of mutating all four sites had not been investigated. In the present work, we mutated these sites in the mouse Foxo1 and found that mutation of all four sites did not decrease Foxo1 O-GlcNAcylation status and transcriptional activity, and would even tend to increase them. In an attempt to identify other O-GlcNAcylation sites, we immunoprecipitated wild-type O-GlcNAcylated Foxo1 and analysed the tryptic digest peptides by mass spectrometry using High-energy Collisional Dissociation. We identified T646 as a new O-GlcNAcylation site on Foxo1. However, site directed mutagenesis of this site individually or together with all four previously identified residues did not impair Foxo1 O-GlcNAcylation and transcriptional activity. These results suggest that residues important for the control of Foxo1 activity by O-GlcNAcylation still remain to be identified. - Highlights: • We mutate four previously identified O-GlcNAcylation sites on Foxo1. • Unexpectedly, these mutations do not reduce Foxo1 O-GlcNAcylation. • These mutation do not reduce Foxo1 transcriptional activity. • We identify a new O-GlcNAcylation site on Foxo1 by mass spectrometry. • Mutation of this site increases Foxo1 transcriptional activity

Investigation of a cholera outbreak in a tea garden of Sivasagar district of Assam

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Bhupendra Narayan Mahanta

2013-01-01

Full Text Available Background: In late May 2012, Bagjan division of Borbam tea estate, of Sivasagar district of Assam was affected by an outbreak of acute watery diarrhea, subsequently confirmed as Vibrio cholerae O1. Objectives: Our objective is to investigate and control the acute diarrheal disease outbreak in Sivasagar district of Assam. Materials and Methods: A physician-epidemiologist-led team did rapid outbreak investigation to confirm the outbreak and instituted treatment and control measures. Quantitative data collection was done using standard schedule and qualitative data by using key informant interview schedule. Results: Spot mapping of cases was done along the garden residential lines. About 120 suspected cases were line listed; with 1:1.23 male: female ratio. Ages ranged from 3 to 70 years (median - 40.5 years. Attack rate was 4.79% with one death; case fatality rate was 0.83%. Open air defecation was practiced by 94.6%. Rectal swabs were positive for V. cholerae O1 (Ogawa. All the piped water samples were class IV unsatisfactory for domestic use. Conclusions: There is a need to improve water and sanitation facility in the tea garden lines along with implementation of a strengthened disease surveillance system through integrated disease surveillance project covering all tea estates.

Revealing the glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of Vibrio cholerae O1, serotype Ogawa with the BSA protein carrier using LC-ESI-QqTOF-MS/MS

Science.gov (United States)

Jahouh, Farid; Saksena, Rina; Kováč, Pavol; Banoub, Joseph

2012-01-01

In this manuscript, we present the determination of glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of Vibrio cholerae O1 serotype Ogawa to BSA using nano- liquid chromatography electrospray ionization quadrupole time-of-flight tandem mass spectroscopy (LC-ESI-QqTOF-MS/MS). The matrix-assisted laser desorption/ionization-TOF/TOF-MS/MS analyses of the tryptic digests of the glycoconjugates having a hapten:BSA ratio of 4.3:1, 6.6:1 and 13.2:1 revealed only three glycation sites, on the following lysine residues: Lys 235, Lys 437 and Lys 455. Digestion of the neoglycoconjugates with the proteases trypsin and GluC V8 gave complementary structural information and was shown to maximize the number of recognized glycation sites. Here, we report identification of 20, 27 and 33 glycation sites using LC-ESI-QqTOF-MS/MS analysis of a series of synthetic neoglycoconjugates with a hapten:BSA ratio of, respectively, 4.3:1, 6.6:1 and 13.2:1. We also tentatively propose that all the glycated lysine residues are located mainly near the outer surface of the protein. PMID:22791257

Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

Science.gov (United States)

Wang, Shaohui; Meng, Qingmei; Dai, Jianjun; Han, Xiangan; Han, Yue; Ding, Chan; Liu, Haiwen; Yu, Shengqing

2014-01-01

Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR) assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs) bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

Directory of Open Access Journals (Sweden)

Shaohui Wang

Full Text Available Systemic infections by avian pathogenic Escherichia coli (APEC are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

The phase transformation and crystallization kinetics of (1 - x)Li2O-xNa2O-Al2O3-4SiO2 glasses

International Nuclear Information System (INIS)

Wang, Moo-Chin; Li, Wang-Long; Cheng, Chih-Wei; Chang, Kuo-Ming; Chen, Yong-Feng; Hsi, Chi-Shiung

2010-01-01

The phase transformation and crystallization kinetics of (1 - x)Li 2 O-xNa 2 O-Al 2 O 3 -4SiO 2 glasses have been studied by using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron diffraction (ED) analysis. The crystallization temperature at the exothermic peak increases from 1171 to 1212 K when the Na 2 O content increases from 0 to 0.6 mol. The crystalline phase is composed of spodumene crystallization when the Na 2 O content increases from 0 to 0.6 mol. The activation energy of spodumene crystallization decreases from 444.0 ± 22.2 to 284.0 ± 10.8 kJ mol -1 when the Na 2 O content increases from 0 to 0.4 mol. Moreover, the activation energy increases from 284.0 ± 10.8 to 446.0 ± 23.2 kJ mol -1 when the Na 2 O content increases from 0.4 to 0.6 mol. The crystallization parameters m and n approach 2, indicating that the surface nucleation and two-dimensional growth are dominant in (1 - x)Li 2 O-xNa 2 O-Al 2 O 3 -4SiO 2 glasses.