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Sample records for cholerae amazonia strain

  1. 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

  2. antimicrobial susceptibility pattern of vibrio cholerae 01 strains

    African Journals Online (AJOL)

    hi-tech

    East African Medical Journal Vol. 77 No. 7 July 2000. ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF VIBRIO CHOLERAE 01 STRAINS DURING TWO CHOLERA OUTBREAKS IN DAR ES SALAAM,. TANZANIA. W.K. Urassa, MD, MSc, MMed, Lecturer, Department of Microbiology and Immunology, Muhimbili University ...

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Vibrio cholerae classical biotype strains reveal distinct signatures in Mexico.

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  6. Cholera

    Science.gov (United States)

    ... causes a large amount of watery diarrhea. Causes Cholera is caused by the bacterium Vibrio cholerae . These bacteria release a toxin that causes an ... include: Africa Some parts of Asia India Bangladesh Mexico South and Central America ... Symptoms of cholera can be mild to severe. They include: Abdominal ...

  7. Detection of cholera (ctx) and zonula occludens (zot) toxin genes in Vibrio cholerae O1, O139 and non-O1 strains.

    Science.gov (United States)

    Rivera, I G; Chowdhury, M A; Sanchez, P S; Sato, M I; Huq, A; Colwell, R R; Martins, M T

    1995-09-01

    Vibrio cholerae O1 and V. cholerae non-O1 strains isolated from environmental samples collected in São Paulo, Brazil, during cholera epidemics and pre-epidemic periods were examined for the presence of toxin genes. V. cholerae O1 strains isolated from clinical samples in Peru and Mexico, and V. cholerae O139 strains from India were also examined for the presence of ctx (cholera toxin gene) and zot (zonula occludens toxin gene) by polymerase chain reaction (PCR). A modified DNA-extraction method applied in this study yielded satisfactory recovery of genomic DNA from vibrios. Results showed that strains of V. cholerae O1 isolated during the preepidemic period were ctx (-)/zot (-) whereas strains isolated during the epidemic were ctx (+)/zot (+). All V. cholerae non-O1 strains tested in the study were ctx (-)/zot (-), whereas all V. cholerae O139 strains were ctx (+)/zot (+). Rapid detection of the virulence genes (ctx and zot) can be achieved by PCR and this can serve as an important tool in the epidemiology and surveillance of V. cholerae.

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

    Directory of Open Access Journals (Sweden)

    Daniel Rios Garza

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

  9. 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...

  10. [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.

  11. [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.

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

    Directory of Open Access Journals (Sweden)

    Mustafizur Rahman

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

  13. Impact of solar irradiation on cholera toxin secretion by different strains of Vibrio cholerae

    CSIR Research Space (South Africa)

    Ssemakalu, CC

    2013-09-01

    Full Text Available , Salomon RN, Garrity K, Reveillaud I, Kopin A, Jackson FR, et al. Vibrio cholerae infection of Drosophila melanogaster mimics the human disease cholera. PLoS Pathog. 2005;1(1):e8. http://dx.doi.org/10.1371/ journal.ppat.0010008 2. World Health...

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

    NARCIS (Netherlands)

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

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

  15. 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...

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

    Science.gov (United States)

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

    2009-03-01

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

  17. Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains.

    OpenAIRE

    Rivera, I G; Chowdhury, M A; Huq, A; Jacobs, D; Martins, M T; Colwell, R R

    1995-01-01

    Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR. A total of 17 fingerprint patterns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (F...

  18. [Algorithm of toxigenic genetically altered Vibrio cholerae El Tor biovar strain identification].

    Science.gov (United States)

    Smirnova, N I; Agafonov, D A; Zadnova, S P; Cherkasov, A V; Kutyrev, V V

    2014-01-01

    Development of an algorithm of genetically altered Vibrio cholerae biovar El Tor strai identification that ensures determination of serogroup, serovar and biovar of the studied isolate based on pheno- and genotypic properties, detection of genetically altered cholera El Tor causative agents, their differentiation by epidemic potential as well as evaluation of variability of key pathogenicity genes. Complex analysis of 28 natural V. cholerae strains was carried out by using traditional microbiological methods, PCR and fragmentary sequencing. An algorithm of toxigenic genetically altered V. cholerae biovar El Tor strain identification was developed that includes 4 stages: determination of serogroup, serovar and biovar based on phenotypic properties, confirmation of serogroup and biovar based on molecular-genetic properties determination of strains as genetically altered, differentiation of genetically altered strains by their epidemic potential and detection of ctxB and tcpA key pathogenicity gene polymorphism. The algorithm is based on the use of traditional microbiological methods, PCR and sequencing of gene fragments. The use of the developed algorithm will increase the effectiveness of detection of genetically altered variants of the cholera El Tor causative agent, their differentiation by epidemic potential and will ensure establishment of polymorphism of genes that code key pathogenicity factors for determination of origins of the strains and possible routes of introduction of the infection.

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

    Directory of Open Access Journals (Sweden)

    Seon Young Choi

    2016-03-01

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  2. 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.

  3. [The development of reagents set in the format of DNA-chip for genetic typing of strains of Vibrio cholerae].

    Science.gov (United States)

    Pudova, E A; Markelov, M L; Dedkov, V G; Tchekanova, T A; Sadjin, A I; Kirdiyashkina, N P; Bekova, M V; Deviyatkin, A A

    2014-05-01

    The necessity of development of methods of genic diagnostic of cholera is conditioned by continuation of the Seventh pandemic of cholera, taxonomic variability of strains of Vibrio cholerae involved into pandemic and also permanent danger of delivery of disease to the territory of the Russian Federation. The methods of genic diagnostic of cholera make it possible in a comparatively short time to maximally minutely characterize strains isolated from patients or their environment. The article presents information about working out reagents set for genetic typing of agents of cholera using DNA-chip. The makeup of DNA-chip included oligonucleotide probes making possible to differentiate strains of V. cholerae on serogroups and biovars and to determine their pathogenicity. The single DNA-chip makes it possible to genetically type up to 12 samples concurrently. At that, duration of analysis without accounting stage of DNA separation makes up to 5 hours. In the progress of work, 23 cholera and non-cholera strains were analyzed. The full compliance of DNA-chip typing results to previously known characteristics of strains. Hence, there is a reason to consider availability of further development of reagents set and possibility of its further application in laboratories of regional level and reference centers.

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

    Directory of Open Access Journals (Sweden)

    Goddeeris Bruno M

    2009-12-01

    Full Text Available Abstract Background Over the last decade, cholera outbreaks in parts of Kenya have become common. Although a number of recent studies describe the epidemiology of cholera in Kenya, there is paucity of information concerning the diversity and occurrence of mobile genetic elements in Vibrio cholerae strains implicated in these outbreaks. A total of 65 Vibrio cholerae O1 El Tor serotype Inaba isolated between 1994 and 2007 from various outbreaks in Kenya were investigated for mobile genetic elements including integrons, transposons, the integrating conjugative elements (ICEs, conjugative plasmids and for their genotypic relatedness. Results All the strains were haemolytic on 5% sheep blood and positive for the Vibrio cholerae El Tor-specific haemolysin toxin gene (hylA by PCR. They all contained strB, sulII, floR and the dfrA1 genes encoding resistance to streptomycin, sulfamethoxazole, chloramphenicol and trimethoprim respectively. These genes, together with an ICE belonging to the SXT/R391 family were transferable to the rifampicin-resistant E. coli C600 en bloc. All the strains were negative for integron class 1, 2 and 3 and for transposase gene of transposon Tn7 but were positive for integron class 4 and the trpM gene of transposon Tn21. No plasmids were isolated from any of the 65 strains. All the strains were also positive for all V. cholera El Tor pathogenic genes except the NAG- specific heat-stable toxin (st gene. None of the strains were positive for virulence genes associated with the V. cholerae classical biotype. All the strains were positive for El Tor-specific CTXphi bacteriophage rstrR repressor gene (CTXETΦ but negative for the Classical, Calcutta, and the Environmental repressor types. Pulse Field Gel Electrophoresis (PFGE showed that regardless of the year of isolation, all the strains bearing the SXT element were clonally related. Conclusions This study demonstrates that the V. cholerae O1 strains carrying an SXT/R391-like

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

    International Nuclear Information System (INIS)

    Das, G.; Das, J.

    1983-01-01

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

  6. IncA/C plasmids harboured in serious multidrug-resistant Vibrio cholerae serogroup O139 strains in China.

    Science.gov (United States)

    Wang, Ruibai; Yu, Dong; Zhu, Lianhui; Li, Jie; Yue, Junjie; Kan, Biao

    2015-03-01

    Vibrio cholerae serogroup O139 emerged in 1992 and is one of two major serogroups to have caused cholera epidemics. After 1998, serious multidrug-resistant (MDR) O139 strains quickly became common in China, showing a multidrug resistance profile to eight antibiotics. It is a great threat to public health, and elucidation of its mechanisms of resistance will provide a helpful guide for the clinical treatment and prevention of cholera. In this study, mega-plasmids from MDR V. cholerae O139 strains were identified by pulsed-field gel electrophoresis (PFGE) without enzyme digestion. One plasmid was isolated and sequenced, belonging to the IncA/C family. Ten antibiotic resistance genes were found in the MDR regions, including a blaTEM-20 gene, and these genes endowed the host with resistance to seven antibiotics. This kind of plasmid was positive in 71.2% (198/278) of toxigenic O139 strains, and the rate of plasmid positivity was consistent with the yearly change in MDR rates of these strains. This study reveals an important role of the IncA/C family plasmid in the spread of multiple antibiotic resistance of epidemic V. cholerae serogroup O139 strains, which has recombined with plasmids from different bacterial species and transferred among V. cholerae strains. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains.

    Science.gov (United States)

    Rivera, I G; Chowdhury, M A; Huq, A; Jacobs, D; Martins, M T; Colwell, R R

    1995-08-01

    Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR. A total of 17 fingerprint patterns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (FP1). The nontoxigenic V. cholerae O1 also yielded four fragments but constituted a different FP group (FP2). A total of 15 different patterns were observed among the V. cholerae non-O1 strains. Two patterns were observed most frequently for V. cholerae non-01 strains, 25% of which have FP3, with five fragments, and 16.7% of which have FP4, with two fragments. Three fragments, 1.75, 0.79, and 0.5 kb, were found to be common to both toxigenic and nontoxigenic V. cholerae O1 strains as well as to group FP3, containing V. cholerae non-O1 strains. Two fragments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2 respectively. The 0.5-kb fragment was common to all strains and serogroups of V. cholerae analyzed. It is concluded from the results of this study, based on DNA FPs of environmental isolates, that it is possible to detect an emerging virulent strain in a cholera-endemic region. ERIC-PCR constitutes a powerful tool for determination of the virulence potential of V. cholerae O1 strains isolated in surveillance programs and for molecular epidemiological investigations.

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

    Science.gov (United States)

    Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; Montes-Colima, Norma Angélica; Moreno-Pérez, María Asunción; Galicia-Nicolás, Adriana Guadalupe; López-Martínez, Irma; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ortíz-Alcántara, Joanna María; Garcés-Ayala, Fabiola; Ramírez-González, José Ernesto

    2016-05-01

    The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by PFGE and by PCR-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the four strains obtained in this study confirmed the presence of Pathogenicity Islands VPI-1 and -2, VSP-1 and -2, and of the integrative element SXT. The genomic structure of the 4 isolates was similar to that of V. cholerae strain 2010 EL-1786, identified during the epidemic in Haiti in 2010. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

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

  12. 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.

    Science.gov (United States)

    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.

  13. 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...

  14. [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.

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

    Science.gov (United States)

    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.

  16. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation

    International Nuclear Information System (INIS)

    Moraes, Ivany Rodrigues de

    1998-01-01

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of 60 Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  17. Molecular analysis of Pasteurella multocida strains isolated from fowl cholera infection in backyard chickens

    Directory of Open Access Journals (Sweden)

    Mohamed-Wael Abdelazeem Mohamed

    2014-01-01

    Conclusion: Based on the previous findings, there are three spreading clusters that may indicate the association of a small number of P. multocida variants with the majority of cases suggesting that certain clones of P. multocida are able to colonize the examined backyard chickens. Also, the ease and rapidity of RAPD-PCR support the use of this technique as alternative to the more labour-intensive SDS-PAGE system for strain differentiation and epidemiological studies of avian P. multocida. Further application of RAPD technology to the examination of avian cholera outbreaks in commercially available flocks may facilitate more effective management of this disease by providing the potential to investigate correlations of P. multocida genotypes, to identify affiliations between bird types and bacterial genotypes, and to elucidate the role of specific bird species in disease transmission.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

  3. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation; Estudo da sensibilidade in vitro de diferentes cepas de Vibio cholerae 01 a radiacao gama de 60Co

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ivany Rodrigues de [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Servicos de Saude; Gelli, Dilma Scala; Jakabi, Miyoko [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Microbiologia; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@net.ipen.br

    1998-07-01

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of {sup 60} Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Bo Pang

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

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Cholera Treatment

    Science.gov (United States)

    ... Diagnosis and Detection Laboratory Testing for Cholera Treatment Rehydration Therapy Antibiotic Treatment Zinc Treatment Prevention & Control Five ... page for current cholera treatment recommendations. Cholera Treatments Rehydration therapy , meaning prompt restoration of lost fluids and ...

  8. 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...

  9. Proteins involved in difference of sorbitol fermentation rates of the toxigenic and nontoxigenic Vibrio cholerae El Tor strains revealed by comparative proteome analysis

    Science.gov (United States)

    2009-01-01

    Background The nontoxigenic V. cholerae El Tor strains ferment sorbitol faster than the toxigenic strains, hence fast-fermenting and slow-fermenting strains are defined by sorbitol fermentation test. This test has been used for more than 40 years in cholera surveillance and strain analysis in China. Understanding of the mechanisms of sorbitol metabolism of the toxigenic and nontoxigenic strains may help to explore the genome and metabolism divergence in these strains. Here we used comparative proteomic analysis to find the proteins which may be involved in such metabolic difference. Results We found the production of formate and lactic acid in the sorbitol fermentation medium of the nontoxigenic strain was earlier than of the toxigenic strain. We compared the protein expression profiles of the toxigenic strain N16961 and nontoxigenic strain JS32 cultured in sorbitol fermentation medium, by using fructose fermentation medium as the control. Seventy-three differential protein spots were found and further identified by MALDI-MS. The difference of product of fructose-specific IIA/FPR component gene and mannitol-1-P dehydrogenase, may be involved in the difference of sorbitol transportation and dehydrogenation in the sorbitol fast- and slow-fermenting strains. The difference of the relative transcription levels of pyruvate formate-lyase to pyruvate dehydrogenase between the toxigenic and nontoxigenic strains may be also responsible for the time and ability difference of formate production between these strains. Conclusion Multiple factors involved in different metabolism steps may affect the sorbitol fermentation in the toxigenic and nontoxigenic strains of V. cholerae El Tor. PMID:19589152

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

    Directory of Open Access Journals (Sweden)

    2005-09-01

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

  11. In vitro evaluation of capsaicin inhibitory effects on zonula occludens toxin in vibrio cholerae ATCC14035 strain

    Directory of Open Access Journals (Sweden)

    Soroor Erfanimanesh

    2014-10-01

    Conclusion: Capsaicin is one of the active compounds of red chili that can drastically suppress zot gene expression and shows promising inhibitory effect against V. cholerae zot production. Thus, routine intake of red chilli, which is easily available and inexpensive, may be an alternative approach to prevent and control symptoms of cholera.

  12. Genome Sequence Analysis of Vibrio cholerae clinical isolates from 2013 in Mexico reveals the presence of the strain responsible for the 2010 Haiti outbreak.

    Science.gov (United States)

    Díaz-Quiñonez, José Alberto

    2017-01-01

    La primera semana de septiembre de 2013, el Sistema Nacional de Vigilancia Epidemiológica identificó dos casos de cólera en Ciudad de México. Los cultivos de ambas muestras se confirmaron como Vibrio cholerae serogrupo O1, serotipo Ogawa, biotipo El Tor. Los análisis iniciales por electroforesis por campos pulsados y por reacción en cadena de la polimerasa indicaron que ambas cepas eran similares, pero diferentes de las previamente reportadas en México. La semana siguiente se identificaron cuatro casos más en una comunidad del Estado de Hidalgo, ubicada a 121 kilómetros al noreste de Ciudad de México. Posteriormente se inició un brote de cólera en la región de La Huasteca. Los análisis genómicos de cuatro cepas obtenidas en este estudio confirmaron la presencia de las islas de patogenicidad VPI -1 y VPI-2, VSP-1 y VSP-2, y del elemento integrador SXT. La estructura genómica de los cuatro aislamientos fue similar a la de V. cholerae cepa 2010 EL-1786, identificada durante la epidemia en Haití en 2010. Este estudio pone de manifiesto que la epidemiología molecular es una herramienta muy poderosa para vigilar, prevenir y controlar enfermedades de importancia en salud pública en México. 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 pulsed-field gel electrophoresis and by polymerase chain reaction-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 strains obtained in this study confirmed the presence of pathogenicity islands VPI-1 and

  13. Host Response in Rabbits to Infection with Pasteurella multocida Serogroup F Strains Originating from Fowl Cholera

    Science.gov (United States)

    The ability of two avian Pasteurella multocida serogroup F strains to induce disease in rabbits was investigated in this study. Two groups of 18 Pasteurella-free rabbits each were intranasally challenged with strains isolated from chicken and turkey, respectively. Half the animals in each challenge ...

  14. [An oral chemical vaccine from the hypertoxigenic strains of the causative agent of cholera KM-76 Inaba and KM-68 Ogawa].

    Science.gov (United States)

    Dzhaparidze, M N; Naumov, A V; Nikitina, G P; Meleshchenko, M V; Dobrova, G V; Zavorotnykh, V I; Gracheva, V P; Zakharova, T L

    1991-04-01

    The material on the development of chemical vaccine, prepared from two newly formed strains (KM-76 Inaba and KM-68 Ogawa) and intended for oral administration, is presented. The conditions for the submerged cultivation of these strains have been established, which makes it possible to increase the production of choleragen 8- to 10-fold and O-antigen 3- to 4-fold in comparison with V. cholerae natural strain 569B. The maximum accumulation of neuraminidase, protease, phospholipase, along with choleragen, has been registered in the logarithmic phase and that of O-antigen, in the stationary phase of growth. The use of strains KM-76 and KM-68 has led to the fourfold increase of the specific activity of the main immunogens, thus permitting the respective increase of the yield of the oral vaccine without changes in its high capacity for the formation of specific antibodies and its low residual toxigenicity.

  15. Cholera in Azov area

    Directory of Open Access Journals (Sweden)

    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

  16. Drinking cholera

    DEFF Research Database (Denmark)

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

    2015-01-01

    . cholerae can survive in the river systems in Bangladesh; however,water sources which have been contaminated with river water are avoided as potential drinkingwater sources. Furthermore, there are no physical connecting points between the river system anddrinking water sources among the study population......, indicating that the primary driver for choleracases in Bangladesh is likely not through the contamination of saline-rich river water into drinkingwater sources.......Objectives: To measure the salinity levels of common water sources in coastal Bangladesh andexplore perceptions of water palatability among the local population to investigate the plausibility oflinking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water...

  17. Development of fowl cholera vaccine: I. Protection of Pasteurella multocida local isolate vaccine against challenge of homologous and heterologous strains.

    Directory of Open Access Journals (Sweden)

    Supar

    2001-03-01

    Full Text Available Pasteurella multocida locally isolated from chicken and ducks (BCC 299, BCC 2331, DY1, DY2, 12TG, 15TG andimported strains (BCC 1359, 1362; HEDDLESTON group 1 and 6 respectively had been tested for its pathogenicity in theprevious study. The aims of this experiment were to study the preparation of local isolate pasteurellosis vaccines and to determine the protective effect of that vaccines in chicken against the highly pathogenic local isolates of P. multocida. Killed monovalent, bivalent and polyvalent pasteurellosis vaccines were prepared and each was adjunvanted with aluminum hydroxide gel at a final concentration of 1.5% and the cell concentration was equal to the No 10 of MacFarland tube standard. Each of the vaccine prepared was used to vaccinated on a group of six week old of layer chicken (8 per group. Each chicken was subcutaneously injected with 0.2 ml of vaccine, four weeks later each was boostered with similar vaccine with the same dose. Two weeks after giving the boostered vaccine each group of chicken were challenged, half with life bacterium of P. Multocida BCC 2331 and other with DY2. Any chick which survive after challenge was designated as protected by vaccination. Before vaccination 1 ml of blood was drawn from each of chicken and then two weeks apart up to challenge. Serum from each sample was separated and kept in deep freeze until tested by enzyme-linked immunosorbent assay (ELISA. Chicken vaccinated with killed whole cell P. multocida vaccines of monovalent (BCC 2331 or DY2 and bivalent (BCC 2331 + DY2 were protected against challenge with live bacterium of either BCC 2331 or DY2 at rate 67-100%. There was no protection in chicken vaccinated with either BCC 299, DY1, 12TG, 15TG, BCC 1359, or 1362 killed vaccine. Similarly no protection of chicken vaccinated with either DY1 + BCC299, 12TG + 15TG or BCC 1359 + BCC 1362 bivalent vaccines. The protection rate of the polyvalent local isolate vaccine was at average 50-75%. All

  18. 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...

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

    Science.gov (United States)

    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.

  20. 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...

  1. The cholera

    International Nuclear Information System (INIS)

    Castaneda, Elizabeth; De la Hoz, Fernando

    1996-01-01

    The cholera is a sharp intestinal infection, characterized by the abrupt appearance of abundant watery diarrhea and vomit, severe dehydration, metabolic imbalance and circulatory collapse; although it can study a symptomatic or to cause light symptomatology. In the cases serious non-treaties the death can take place in the 24 later hours to its appearance; the lethality in these cases can exceed 50 percent. However. With the treatment of re-hydration appropriate. This decreases to less ten percent. The cholera is related in direct form with the poverty; it is presented where accumulation and lack of measures of hygiene exist and of drinkable water. It is for it that the best strategy to prevent the illness is to eliminate the factors that favor its transmission: to improve the quality of the water and to implement elementary measures of hygiene. When the environmental conditions are favorable, the cholera has been absent

  2. 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.

    Science.gov (United States)

    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.

  3. 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

    Directory of Open Access Journals (Sweden)

    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

  4. Vibrio cholerae infection, novel drug targets and phage therapy.

    Science.gov (United States)

    Fazil, Mobashar Hussain Urf Turabe; Singh, Durg V

    2011-10-01

    Vibrio cholerae is the causative agent of the diarrheal disease cholera. Although antibiotic therapy shortens the duration of diarrhea, excessive use has contributed to the emergence of antibiotic resistance in V. cholerae. Mobile genetic elements have been shown to be largely responsible for the shift of drug resistance genes in bacteria, including some V. cholerae strains. Quorum sensing communication systems are used for interaction among bacteria and for sensing environmental signals. Sequence analysis of the ctxB gene of toxigenic V. cholerae strains demonstrated its presence in multiple cholera toxin genotypes. Moreover, bacteriophage that lyse the bacterium have been reported to modulate epidemics by decreasing the required infectious dose of the bacterium. In this article, we will briefly discuss the disease, its clinical manifestation, antimicrobial resistance and the novel approaches to locate drug targets to treat cholera.

  5. Avian cholera

    Science.gov (United States)

    Friend, Milton

    1999-01-01

    Avian cholera is a contagious disease resulting from infection by the bacterium Pasteurella multocida. Several subspecies of bacteria have been proposed for P. multocida, and at least 16 different P. multocida serotypes or characteristics of antigens in bacterial cells that differentiate bacterial variants from each other have been recognized. The serotypes are further differentiated by other methods, including DNA fingerprinting. These evaluations are useful for studying the ecology of avian cholera (Fig. 7.1), because different serotypes are generally found in poultry and free-ranging migratory birds. These evaluations also show that different P. multocida serotypes are found in wild birds in the eastern United States than those that are found in the birds in the rest of the Nation (Fig. 7.2).

  6. 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...

  7. 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,...

  8. 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.

  9. 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.

    Directory of Open Access Journals (Sweden)

    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.

  10. [Mexican phenotype and genotype Vibrio cholerae 01].

    Science.gov (United States)

    Giono, S; Gutiérrez Cogno, L; Rodríguez Angeles, G; del Rio Zolezzi, A; Valdespino González, J L; Sepúlveda Amor, J

    1995-01-01

    This paper presents the phenotypical and genotypical characterization of 26922 Vibrio cholerae 01 strains isolated in Mexico from 1991 to 1993. All strains isolated were El Tor biovar. Strains were sensitive to antibiotics excluding furazolidone, streptomycin and sulfisoxasole to which we found resistance in 97% and we are using this characteristic as epidemiological markers. We detected a marked change in frequency of Inaba serotype from 1991, when it was dominant, with 99.5%, until 1992 when Ogawa serotype turned to be dominant with 95% of isolates. All Vibrio cholerae 01 strains, except one Ogawa strain, were to igenic, and V. choleraeno 01 were not toxigenic by ELISA, PCR and cell culture tests. Dominant ribotype was 5, but we found some strains with 6a pattern and two with ribotype 12. We are searching for ribotype 2 among hemolytic strains in order to learn if there is any relation to Gulf Coast strains prevalent in the USA, but until now we have not found any V. cholerae ribotype 2 in our isolates. Even if rapid tests are recommended for immediate diagnosis of cholera, it is necessary to continue bacterial isolation in order to have strains for phenotyping and genotyping studies that may support epidemiological analysis.

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

    Directory of Open Access Journals (Sweden)

    Liliana Candida Dengo-Baloi

    /97 Tetracycline, 56% (5/13 Doxycycline, 56% (39/70 Azithromycin and 0% (0/101 for Ciprofloxacin. PCR analysis suggested strains of V. cholerae O1 being descendants of the current seventh pandemic V. cholerae O1 CIRS 101 hybrid variant. The V. cholerae O1 currently causing cholera epidemics in north and central Mozambique confirmed a CTXΦ genotype and a molecular arrangement similar to the V. cholerae O1 CIRS 101.Although V. cholerae infections in Mozambique are generally not treated with antibiotics circulating strains of the bacteria showed high frequency of in vitro resistance to available antibiotics. Continuous monitoring of antibiotic resistance pattern of epidemic strains is therefore crucial since the appearance of antibiotic resistance can influence cholera control strategies.

  12. 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

    /97) Tetracycline, 56% (5/13) Doxycycline, 56% (39/70) Azithromycin and 0% (0/101) for Ciprofloxacin. PCR analysis suggested strains of V. cholerae O1 being descendants of the current seventh pandemic V. cholerae O1 CIRS 101 hybrid variant. The V. cholerae O1 currently causing cholera epidemics in north and central Mozambique confirmed a CTXΦ genotype and a molecular arrangement similar to the V. cholerae O1 CIRS 101. Although V. cholerae infections in Mozambique are generally not treated with antibiotics circulating strains of the bacteria showed high frequency of in vitro resistance to available antibiotics. Continuous monitoring of antibiotic resistance pattern of epidemic strains is therefore crucial since the appearance of antibiotic resistance can influence cholera control strategies.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  14. Cholera Illness and Symptoms

    Science.gov (United States)

    ... Share Compartir Cholera is an acute, diarrheal illness caused by infection of the intestine with the bacterium Vibrio cholerae and is spread by ingestion of contaminated food or water. The infection is often mild or without symptoms, ...

  15. Cholera Prevention and Control

    Science.gov (United States)

    ... name=”commit” type=”submit” value=”Submit” /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention & Control Topics Ending Cholera: The Global Roadmap to 2030 ...

  16. Cholera in Zimbabwe

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

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

  17. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

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

    . cholerae El Tor strain N16961, showed hemolysis and proteolysis activity but none of them exhibited any hemagglutinin activity on human erythrocytes. The study findings indicate that V. cholerae contamination is mostly originated in and around kitchen area rather than latrine area. Contaminated food...... and water supply may be the reason behind this relatively high presence of virulence factors in food plates and water pots. Direct exposure routes of disease transmission should be a major consideration in cholera prevention policies. Investigation of household contamination of Vibrio cholerae in Bangladesh......The role of in-house transmission on the incidence of Vibrio cholerae, the deadly waterborne pathogen, is still not developed. The aim of the current study was to investigate possible contamination routes in household domain for effective cholera control in Bangladesh. To examine the prevalence...

  18. Vibrio cholerae Colonization of Soft-Shelled Turtles.

    Science.gov (United States)

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

    2017-07-15

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

  19. Association of Heavy Rainfall on Genotypic Diversity in V. cholerae Isolates from an Outbreak in India

    Directory of Open Access Journals (Sweden)

    A. K. Goel

    2011-01-01

    Full Text Available The outbreak of waterborne disease cholera has been associated with rainfall and flooding events by contamination of potable water with environmental Vibrio cholerae. The continuation of the epidemic in a region, however, is often due to secondary transmission of the initial outbreak strain through human waste. This paper reports, on the contrary, a rapid shift of genotype from one V. cholerae strain to another one in an epidemic region. V. cholerae isolated from patients during 2005 cholera epidemic in Chennai, India were characterized using PCR identification of toxin genes, antibiogram, and genomic fingerprinting analysis. The results showed that in spite of the similarity of toxin genes and antibiogram, the Vibrio isolates grouped into two different clusters based on the ERIC-PCR fingerprinting. Each cluster corresponded to a distinct peak of cholera outbreak, which occurred after separate heavy rainfall. The results suggest that the rainfall event can bring various genotypes of V. cholerae strains causing multiple outbreaks.

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

    Science.gov (United States)

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

    2014-09-01

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

  1. A novel kit for rapid detection of Vibrio cholerae O1.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  4. 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

  5. [The cholera epidemic in Latin America].

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Structural organization of the transfer RNA operon I of Vibrio cholerae

    Indian Academy of Sciences (India)

    Nine major transfer RNA (tRNA) gene clusters were analysed in various Vibrio cholerae strains. Of these, only the tRNA operon I was found to differ significantly in V. cholerae classical (sixth pandemic) and El Tor (seventh pandemic) strains. Amongst the sixteen tRNA genes contained in this operon, genes for tRNA Gln3 ...

  8. Cholera Fact Sheet

    Science.gov (United States)

    ... news-room/fact-sheets/detail/cholera","@context":"http://schema.org","@type":"Article"}; العربية 中文 français русский español ... that includes feedback at the local level and information-sharing at the global level. Cholera cases are ...

  9. What is cholera?

    DEFF Research Database (Denmark)

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

    2016-01-01

    more commonly described than death (47%) as negative effects of cholera. Conclusions: The results from this study are suggestive of a need for reformulation of cholera and diarrhea communication. Messaging should be based on signs of dehydration, foregoing the use of medical terminology....

  10. 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....

  11. Characterization of a clinical Vibrio cholerae O139 isolate from Mexico.

    Science.gov (United States)

    Parveen, Salina; Farrah, Samuel R; Gonzalez-Bonilla, Celia; Zamudio, Altagracia V; Tamplin, Mark L

    2003-01-01

    Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.

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

    Directory of Open Access Journals (Sweden)

    Jussi A. O. Meriluoto

    2012-06-01

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

  13. Radiolabelling of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-11-01

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

  14. Cholera - management and prevention.

    Science.gov (United States)

    Davies, Hannah G; Bowman, Conor; Luby, Stephen P

    2017-06-01

    Cholera is an acute secretory diarrhoeal infection caused by the bacterium Vibrio cholerae. It is likely to have originated in the Indian sub-continent; however, it spread to cause six worldwide pandemics between 1817-1923. The ongoing seventh worldwide pandemic of cholera began in 1961. The intensity, duration and severity of cholera epidemics have been increasing, signaling the need for more effective control and prevention measures. The response to the cholera pandemics of the 19th century led to the development of safe and effective sanitation and water systems which have effectively removed the risk of cholera in many settings. However, such systems are not in place to protect billions of people worldwide. Although some progress has been made in expanding access to water in recent years, achieving optimal infrastructure will, in the most optimistic scenario, take decades. Climate change, extreme weather events and rapid urbanisation suggests that alternatives to the current paradigm of providing large centralised water and sanitation systems should be considered, including smaller decentralised systems. The aim of this review paper is to provide an overview of current knowledge regarding management of cholera with a focus on prevention measures including vaccination and water and sanitation interventions. © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  15. Radiolabelling of cholera toxin

    International Nuclear Information System (INIS)

    Santos, R.G.; Neves, Nicoli M.J.; Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L.; Lima, M.E. de; Nicoli, J.R.

    1999-01-01

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

  16. 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

    Directory of Open Access Journals (Sweden)

    Jorge Timenetsky

    1992-10-01

    Brazil for microbiological qualification of chemical disinfectants for commercial purposes. Domestic disinfectants are tested in this way against Salmonella choleraesuis and Staphylococcus aureus ATCC strains, was chosen for this evaluation Vibrio cholerae in view of its current importance in Brazil, in terms of Public Health associated with the study of the disinfectant's antimicrobial activities. Nineteen disinfectant products for domestic use for available to the public were evaluated microbiologically by means of simplified Use-Dilution test with 10 carriers. The active compounds of the products included formaldeyde, phenols, cresols, quaternary ammonium compouds, chlorine and ethanol. Seven were mixtures of these. According to the recommendations for their use, sixteen products should be used undiluted. Under these conditions, 9 disinfectants were vibriocides and 7 did not demonstrate this antibacterial activity. Four products in dilutions not clearly specificated were also ineffective. The vibriocide products which must used without dilution were tested again, diluted at 1:2. These solutions did not inactivate V. cholerae showing that, microbiologically, their active compounds are used in limited concentrations. Commercial alcohol (95.5°GL at 1:3, chlorine 2.8% Água sanitária at 1:200 and Lysoform at 1:20 came up to the standards required by the test.

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

    Directory of Open Access Journals (Sweden)

    Gregory A Price

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

  18. What is Cholera?

    Indian Academy of Sciences (India)

    Cholera is a rapidly dehydrating watery diarrheal disease that can lead to death in less than 24 hours if untreated, making it, according to WHO, “one of the most rapidly fatal infectious illnesses known” ...

  19. Cholera in the Americas.

    Science.gov (United States)

    1991-01-01

    The cholera epidemic 1st hit South America in January 1991 in the coastal town of Chancay, Peru. In 2 weeks, it spread over 2000 km of the Pacific coast. By the end of the 1st month, it had already reached the mountains and tropical forests. By August 1991, cholera cases were reported in order of appearances in Ecuador, Colombia, Chile, Brazil, the US, Mexico, Guatemala, Bolivia, and El Salvador. Health authorities still do not know how it was introduced into South America. The case fatality rate has remained at a low of 1%, probably due to the prompt actions of health authorities in informing the public of the epidemic and what preventive cautions should be taken. This epidemic is part of the 7th pandemic which originated in Celebes, Indonesia in 1961. Cholera can spread relatively unchecked in Latin America because sewage in urban areas is not treated even though they do have sewage collection systems. The untreated wastewater enters rivers and the ocean. Consumption of raw seafood is not unusual and has been responsible for cholera infection in some cases. In fact, many countries placed import restrictions on marine products from Peru following the outbreak at a loss of $US10-$US40 million. Municipal sewage treatment facilities, especially stabilization ponds, would prevent the spread of cholera and other pathogens. In rural areas, pit latrines located away from wells can effectively dispose of human wastes. Most water supplies in Latin America are not disinfected. Disinfection drinking water with adequate levels of chlorine would effectively destroy V. cholera. If this is not possible, boiling the water for 2-3 minutes would destroy the pathogen. Any cases of cholera must be reported to PAHO. PAHO has responded to the outbreak by forming a Cholera Task Force and arranged transport of oral rehydration salts, intravenous fluids, antibiotics, and other essential medical supplies.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  2. [Cholera in pediatrics].

    Science.gov (United States)

    Lezama-Basulto, L A; Mota-Hernández, F

    1993-09-01

    Cholerae is a grave and acute bacterial intestine infection which is caused by a bacilo, V. cholerae 01, that produces toxic products. Its clinical symptoms range from abundant liquid diarrhoea combined with vomiting and rapid dehydration. It is highly lethal when right treatment is not applied. There are also cases of cholera where victims do not show any symptoms of it, that is asymptomatic carriers. Any clinical suspicion of cholerae has to be corroborated by epidemiological data and its diagnostic confirmation should be done by isolating the bacteria, V. cholerae. When beginning the treatment, it is not necessary to confirm the diagnostic and this is based on the restitution of the liquids lost through vomiting and facing using any methods that are recommended for any other type of diarrhoea. The antimicrobial treatment is used only for grave cases. This present revision includes recent knowledge about cholerae emphasising on the effective management of cases through an adequate use of right treatment methods and also using the principal prevention measures against dissemination of this disease.

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

    Science.gov (United States)

    Christenson, Bernard

    2008-01-01

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

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

    Science.gov (United States)

    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.

  5. 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

  6. 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.

  7. 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

  8. The global burden of cholera

    Science.gov (United States)

    Lopez, Anna Lena; You, Young Ae; Kim, Young Eun; Sah, Binod; Maskery, Brian; Clemens, John

    2012-01-01

    Abstract Objective To estimate the global burden of cholera using population-based incidence data and reports. Methods Countries with a recent history of cholera were classified as endemic or non-endemic, depending on whether they had reported cholera cases in at least three of the five most recent years. The percentages of the population in each country that lacked access to improved sanitation were used to compute the populations at risk for cholera, and incidence rates from published studies were applied to groups of countries to estimate the annual number of cholera cases in endemic countries. The estimates of cholera cases in non-endemic countries were based on the average numbers of cases reported from 2000 to 2008. Literature-based estimates of cholera case-fatality rates (CFRs) were used to compute the variance-weighted average cholera CFRs for estimating the number of cholera deaths. Findings About 1.4 billion people are at risk for cholera in endemic countries. An estimated 2.8 million cholera cases occur annually in such countries (uncertainty range: 1.4–4.3) and an estimated 87 000 cholera cases occur in non-endemic countries. The incidence is estimated to be greatest in children less than 5 years of age. Every year about 91 000 people (uncertainty range: 28 000 to 142 000) die of cholera in endemic countries and 2500 people die of the disease in non-endemic countries. Conclusion The global burden of cholera, as determined through a systematic review with clearly stated assumptions, is high. The findings of this study provide a contemporary basis for planning public health interventions to control cholera. PMID:22461716

  9. [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)

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

    International Nuclear Information System (INIS)

    Ahmed, S.

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Daniel Unterweger

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

  12. The environment and the hydroelectric in Amazonia

    International Nuclear Information System (INIS)

    La Rovere, E.L.

    1992-01-01

    Some aspects about social and environmental impacts due to the hydroelectric power plants constructed in Amazonia region are presented, including considerations of energy planning and management with international example. (C.G.C.)

  13. Cholera in Children

    Science.gov (United States)

    ... oral antibiotic will be given. More serious skin infections and bacteria in the blood are treated in the hospital with intravenous antibiotics. In some cases, your child may require surgery to drain pus and damaged tissues. Prevention V cholerae can be killed by boiling, filtering, ...

  14. Improving immunization approaches to cholera.

    Science.gov (United States)

    Saha, Amit; Rosewell, Alexander; Hayen, Andrew; MacIntyre, C Raina; Qadri, Firdausi

    2017-03-01

    Cholera's impact is greatest in resource-limited countries. In the last decade several large epidemics have led to a global push to improve and implement the tools for cholera prevention and control. Areas covered: PubMed, Google Scholar and the WHO website were searched to review the literature and summarize the current status of cholera vaccines to make recommendations on improving immunization approaches to cholera. Oral cholera vaccines (OCVs) have demonstrated their effectiveness in endemic, outbreak response and emergency settings, highlighting their potential for wider adoption. While two doses of the currently available OCVs are recommended by manufacturers, a single dose would be easier to implement. Encouragingly, recent studies have shown that cold chain requirements may no longer be essential. The establishment of the global OCV stockpile in 2013 has been a major advance in cholera preparedness. New killed and live-attenuated vaccines are being actively explored as candidate vaccines for endemic settings and/or as a traveller's vaccine. The recent advances in cholera vaccination approaches should be considered in the global cholera control strategy. Expert commentary: The development of affordable cholera vaccines is a major success to improve cholera control. New vaccines and country specific interventions will further reduce the burden of this disease globally.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Yan Boucher

    2016-07-01

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

  17. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    ). This communalis- tic and symbiotic relationship enables V. cholerae, to sur- vive in unfavorable environmental conditions (Deborah et al., 2001; Menon et al., 2000). Some strains under certain conditions assume spore like or dormant forms (viable but non...

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

    International Nuclear Information System (INIS)

    Smirnova, N.I.; Livanova, L.F.; Shaginyan, I.A.; Motin, V.L.

    1986-01-01

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

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

    OpenAIRE

    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 cou...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Brendan J O'Hara

    2017-06-01

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

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

    Science.gov (United States)

    O'Hara, Brendan J; Barth, Zachary K; McKitterick, Amelia C; Seed, Kimberley D

    2017-06-01

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

  4. Two-year participatory monitoring of extractivism in Brazilian Amazonia

    DEFF Research Database (Denmark)

    Cámara-Leret, Rodrigo; Newton, Peter; Hawes, Joseph

    basin of western Brazilian Amazonia. We discuss the most important extractive activities for ~100 households, how socio-economic factors influence NTFP extractive patterns across households, and the benefits and constraints of using participatory approaches to monitor extractivism in Amazonia....

  5. 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...

  6. 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.

  7. 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

  8. 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.

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

    Science.gov (United States)

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

    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

  10. 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.

  11. 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

  12. 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.

  13. 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...

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

    KAUST Repository

    Weynberg, Karen D.

    2015-12-08

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

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

    KAUST Repository

    Weynberg, Karen D.; Voolstra, Christian R.; Neave, Matthew J.; Buerger, Patrick; van Oppen, Madeleine J. H.

    2015-01-01

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

  16. Greenhouse gases study in Amazonia

    International Nuclear Information System (INIS)

    D'Amelio, Monica Tais Siqueira

    2006-01-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO 2 sources. The Amazon forest is a significant source of N 2 O by soil process, and CH 4 by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO 2 , CH 4 , CO, H 2 , N 2 O and SF 6 have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO 2 flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO 2 flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H 2 gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO 2 sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that, in the 2004 and 2005 wet seasons and 2004 dry season comparison it was

  17. 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.

    Science.gov (United States)

    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.

  18. Environmental Monitoring of Endemic Cholera

    Science.gov (United States)

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

    2012-12-01

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

  19. Flow cytofluorometric monitoring of leukocyte apoptosis in experimental cholera

    Science.gov (United States)

    Lotsmanova, Ekaterina Y.; Kravtsov, Alexander L.; Livanova, Ludmila F.; Kobkova, Irina M.; Kuznetsov, Oleg S.; Shchukovskaya, Tatyana N.; Smirnova, Nina I.; Kutyrev, Vladimir V.

    2003-10-01

    Flow cytofluorometric DNA analysis was applied to determine of the relative contents of proliferative (more then 2C DNA per cell) and apoptotic (less then 2C DNA per cell) leukocytes in blood of adult rabbits, challenged with 10,000 times the 50 % effective dose of Vibrio cholerae virulent strain by the RITARD technique. It has been shown that irreversible increase the percentage of cells carrying DNA in the degradation stage brings to disbalance between the genetically controlled cell proliferation and apoptosis that leads to animal death from the cholera infection. Such fatal changes were not observed in challenging of immunized animals that were not died. Thus received data show that the flow cytofluorometric measurements may be used for detection of transgressions in homeostasis during acute infection diseases, for outlet prognosis of the cholera infection.

  20. Ultraviolet inactivation and photoreactivation of the cholera phage 'Kappa'

    International Nuclear Information System (INIS)

    Samad, S.A.; Bhattacharyya, S.C.; Chatterjee, S.N.

    1987-01-01

    The lysogenic cholera phage, 'Kappa' is some ten to twenty folds more resistant to UV (254 nm) than are most of the T. phages of E. coli, or the cholera phage PL 163/10, or the host V. cholerae strain H218 Sm r , the 37% (D 37 ) and 10% (D 10 ) survival doses being 255.8 J/m 2 and 633.6 J/m 2 respectively. The UV-irradiated 'Kappa' phages could be photoreactivated in the host V. cholerae strain H218 Sm r to a maximum extent of 40%. The removal of the number of lethal hits per phage by the survival-enhancement treatment (photoreactivation) with time followed an exponential relation, the constant probability of removal of lethal hit per unit time being 2.8x10 -2 min -1 . The UV-irradiated phages could also be Weigle reactivated in the host strain of H218 Sm r by a small degree, the maximum reactivation factor (ratio of survivals in UV-irradiated and non-irradiated hosts) being 1.50. (orig.)

  1. Epidemic cholera spreads like wildfire

    Science.gov (United States)

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

    2014-01-01

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

  2. Environmental Factors Influencing Epidemic Cholera

    Science.gov (United States)

    Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

    2013-01-01

    Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

  3. Social and cultural features of cholera and shigellosis in peri-urban and rural communities of Zanzibar

    Directory of Open Access Journals (Sweden)

    Hutubessy Raymond

    2010-11-01

    Full Text Available Abstract Background Responding to the high burden of cholera in developing countries, the WHO now considers vaccination as a supplement to the provision of safe drinking water and improved sanitation in the strategy for cholera control in endemic settings. Cultural concepts of illness affect many aspects of public health. In the first step of a two-step strategy to examine determinants of cholera vaccine acceptance, this study identified social and cultural features of diarrhoeal illness for cholera control in endemic communities. Methods A cultural epidemiological study with locally adapted vignette-based interviews was conducted in two cholera-endemic communities of Zanzibar. A random sample of unaffected peri-urban (n = 179 and rural (n = 177 adults was interviewed to study community ideas of cholera and shigellosis, considering categories of distress, perceived causes, and help-seeking behaviour. Results Cholera was recognised by 88%. Symptoms of dehydration were most prominent in reports at the peri-urban site. Interference with work leading to strain on household finances was frequently emphasised. Dirty environment was the most prominent perceived cause, followed by unsafe drinking water and germ-carrying flies. Causes unrelated to the biomedical basis of cholera were reported more often by rural respondents. Rural women had more difficulty (20% to identify a cause than men (7.1%, p = 0.016. Peri-urban self treatment emphasised rehydration; the rural community preferred herbal treatment and antibiotics. Shigellosis was recognised by 70%. Fewer regarded it as very serious compared with cholera (76% vs. 97%, p Conclusions This study clarified local views of cholera and shigellosis relevant for diarrhoeal disease control in Zanzibar. The finding that rural women were less likely than men to specify causes of cholera suggests more attention to them is required. Better health education is needed for cholera in rural areas and for shigellosis

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

    Directory of Open Access Journals (Sweden)

    Rolf S Kaas

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

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

    Science.gov (United States)

    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.

  6. In a time of cholera.

    Science.gov (United States)

    Grace, P A

    2014-03-01

    Dr. Nathaniel Alcock in his book A treatise on cholera described 22 cases of cholera that he treated in 1832. Blood-letting, either by leeches or venesection, was an essential part of the treatment. The belief was that reducing the blood volume would relieve stress on the heart and lungs allowing for better function. The receipts of the Townsend Street Cholera Hospital where Dr. Alcock worked show how extensive the practice was. Outside Dublin, local Boards of Health dealt with the cholera epidemic. Various public measures such as street cleaning and removal of patients to temporary hospitals were undertaken and various cures were tried. The overall mortality rate from cholera in Ireland during the epidemic was 38 %, but in some areas much higher. Even as cholera was spreading in the 1830s, a number of doctors were showing that intravenous fluids could dramatically alter the course of the disease. Unfortunately, their work was ignored and blood-letting continued to be a major component of the treatment of cholera for another 55 years.

  7. The domestication of Amazonia before European conquest.

    Science.gov (United States)

    Clement, Charles R; Denevan, William M; Heckenberger, Michael J; Junqueira, André Braga; Neves, Eduardo G; Teixeira, Wenceslau G; Woods, William I

    2015-08-07

    During the twentieth century, Amazonia was widely regarded as relatively pristine nature, little impacted by human history. This view remains popular despite mounting evidence of substantial human influence over millennial scales across the region. Here, we review the evidence of an anthropogenic Amazonia in response to claims of sparse populations across broad portions of the region. Amazonia was a major centre of crop domestication, with at least 83 native species containing populations domesticated to some degree. Plant domestication occurs in domesticated landscapes, including highly modified Amazonian dark earths (ADEs) associated with large settled populations and that may cover greater than 0.1% of the region. Populations and food production expanded rapidly within land management systems in the mid-Holocene, and complex societies expanded in resource-rich areas creating domesticated landscapes with profound impacts on local and regional ecology. ADE food production projections support estimates of at least eight million people in 1492. By this time, highly diverse regional systems had developed across Amazonia where subsistence resources were created with plant and landscape domestication, including earthworks. This review argues that the Amazonian anthrome was no less socio-culturally diverse or populous than other tropical forested areas of the world prior to European conquest. © 2015 The Author(s).

  8. Miocene freshwater Mollusca from western Brazilian Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.; Ranzi, A.; Räsänen, M.E.

    2006-01-01

    Thirteen species of fossil molluscs are reported from the Solimões Formation of western Brazilian Amazonia. Based on mammalian chronology of the Solimões Formation and radiometric ages reported from coeval deposits in adjacent Peru, the age of the fauna is established as Late Miocene. The fauna

  9. Lizards of Brazilian Amazonia (Reptilia: Squamata)

    NARCIS (Netherlands)

    Avila-Pires, T.C.S.

    1995-01-01

    Eighty-nine species of lizards, six of which polytypic (forming a total of 97 taxa), are presently known from Brazilian Amazonia. This number includes six species and one subspecies described as new to science in this paper: Stenocercus fimbriatus, Lepidoblepharis hoogmoedi, Leposoma osvaldoi, L.

  10. The absence of a flagellum leads to altered colony morphology, biofilm development and virulence in Vibrio cholerae O139

    Science.gov (United States)

    Watnick, Paula I.; Lauriano, Crystal M.; Klose, Karl E.; Croal, Laura; Kolter, Roberto

    2010-01-01

    Summary Throughout most of history, epidemic and pandemic cholera was caused by Vibrio cholerae of the serogroup O1. In 1992, however, a V. cholerae strain of the serogroup O139 emerged as a new agent of epidemic cholera. Interestingly, V. cholerae O139 forms biofilms on abiotic surfaces more rapidly than V. cholerae O1 biotype El Tor, perhaps because regulation of exopolysaccharide synthesis in V. cholerae O139 differs from that in O1 El Tor. Here, we show that all flagellar mutants of V. cholerae O139 have a rugose colony morphology that is dependent on the vps genes. This suggests that the absence of the flagellar structure constitutes a signal to increase exopolysaccharide synthesis. Furthermore, although exopolysaccharide production is required for the development of a three-dimensional biofilm, inappropriate exopolysaccharide production leads to inefficient colonization of the infant mouse intestinal epithelium by flagellar mutants. Thus, precise regulation of exopolysaccharide synthesis is an important factor in the survival of V. cholerae O139 in both aquatic environments and the mammalian intestine. PMID:11136445

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

    International Nuclear Information System (INIS)

    Tiganova, I.G.; Evdokimova, N.M.; Aleshkin, G.I.

    1988-01-01

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

  12. 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.

  13. 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.

  14. [Genodiagnosis and molecular typing of the pathogens for plague, cholera, and anthrax].

    Science.gov (United States)

    Kutyrev, V V; Smirnova, N I

    2003-01-01

    The paper contains a survey of published data about the use of DNA-diagnostics in indicating and identifying the causative agents of highly dangerous infections like plague, cholera and anthrax. A discussion of data about the genetic relationship between strains of the mentioned causative agents isolated from different sources by using the molecular-typing methods as well as about the evolution ties between strains of different origins is in the focus of attention. Results of comparative studies of nucleotide sequences of genomes or of individual genomes in different Yersinia pestis, Vibrio cholerae and Bacillus anthracis strains, which are indicative of the evolution of their pathogenicity, are also under discussion.

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

    Directory of Open Access Journals (Sweden)

    Kevin eEsteves

    2015-07-01

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

  16. Ocorrência de linhagens humana e silvestre de Schistosoma mansoni, na pré-amazônia: I - estudo em moluscos Occurrence of wild and human strains of Schistosoma mansoni in lower Amazonia: I - study in moluscs

    Directory of Open Access Journals (Sweden)

    Othon de Carvalho Bastos

    1982-10-01

    Full Text Available Foram isoladas na região da Baixada Maranhense (Brasil, linhagens humana (H e silvestre(S de Schistosoma mansoni a partir de miracídios eclodidos de ovos encontrados em fezes de doentes humanos autóctones da Região e de fígados de roedores silvestres naturalmente infectados. Biomphalaria glabrata, descentes de caramujos coletados no campo, foram expostos, isoladamente, aos miracídios H e S, mantidos isolados em moluscário e observados durante 100 dias. Moluscos normais foram mantidos nas mesmas condições de ambiente em que foram submetidos os infectados e tomados como controle da experiência. Foram anotados os indices de infecção dos moluscos, as datas da eliminação de cercárias, quantidade de larvas eliminadas e mortalidade dos moluscos. Os dados sugeriram melhor adaptação do esquistossomo da linhagem H à B. glabrata. A linhagem S, por sua vez, foi três vezes mais virulenta do que a linhagem H. Estes dados foram comparados com os encontrados na literatura especializada e verificado diversidades nos comportamentos parasitológicos das linhagens em estudo, quando comparados com os encontrados nas linhagens H e S oriundas do Vale do Rio Paraíba do Sul, no Estado de São Paulo (Brasil.The wild (W and human (H strains of Schistosoma mansoni were isolated in the Lowland Region of the Maranhão State (Brazil. The snail progenies from Biomphalaria glabrata collected from that region were exposed to the W miracidia, obtained from livers of wild rodents, and H miracidia from eggs in human stools. A control gruop of normal snails was kept in the same conditions as the infected one. The date of the elimination of cercariae, the quantity of eliminated larvae, the infection index of the moluscs and the mortality rate of the snails were recorded. These data suggested better adaptation of the H strain to B. glabrata. The W strain presented three times more virulence to snails than the H strain. These results were compared with published

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  19. Update: cholera--Western Hemisphere, and recommendations for treatment of cholera.

    Science.gov (United States)

    1991-08-16

    Epidemic cholera appeared in Peru in January 1991 and subsequently spread to Ecuador, Colombia, Chile, Brazil, Mexico, and Guatemala. Cholera can be a severe, life-threatening illness but is highly preventable and easily treated; however, few health-care practitioners in the United States have experience identifying and treating cholera. This report provides an update on cholera in the Western Hemisphere and provides recommendations on the clinical diagnosis and treatment of cholera in the United States.

  20. Epidemic Risk from Cholera Introductions into Mexico

    OpenAIRE

    Moore, Sean M.; Shannon, Kerry L.; Zelaya, Carla E.; Azman, Andrew S.; Lessler, Justin

    2014-01-01

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resultin...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  3. Prevailing clone (ST69) of Vibrio cholerae O139 in India over 10 years.

    Science.gov (United States)

    Anandan, Shalini; Devanga Ragupathi, Naveen Kumar; Muthuirulandi Sethuvel, Dhiviya Prabaa; Thangamani, Suji; Veeraraghavan, Balaji

    2017-01-01

    Vibrio cholerae is responsible for the cause of severe life-threatening infection known as cholera. The study aimed to analyze the genetic make-up of V. cholerae O139 isolates from India and compare its phylogeny with the global strains. The genome data revealed that all isolates were of same sequence type (ST69) which belongs to seventh pandemic clone, with same virulence gene profile and, antimicrobial resistance gene profile except for two isolates. No known CRISPR repeats were identified in any of these isolates. Three different phages were identified among the isolates. All the isolates were found to harbour int SXT and seventh pandemic-specific gene (VC2346). Results from this study enhance our understanding on the persistence of ST69 V. cholerae O139 over 20 years.

  4. 9 CFR 311.3 - Hog cholera.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hog cholera. 311.3 Section 311.3... CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.3 Hog cholera. (a) The carcasses of all hogs affected with hog cholera shall be condemned. (b) Inconclusive but suspicious symptoms...

  5. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn-Beckers, Petronella; Doldersum, Tom; Useya, Juliana; Augustijn, Dionysius C.M.

    2016-01-01

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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Soni Priya Valeru

    2014-01-01

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

  8. Genetic characterization of ØVC8 lytic phage for Vibrio cholerae O1.

    Science.gov (United States)

    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

  9. [Complications and treatment of cholera during pregnancy].

    Science.gov (United States)

    Figueroa Damian, R; Villagrana Zesati, R; Kasis Ariceaga, D

    1994-07-01

    Since 1961 cholera has spread in many countries reaching a pandemic form. Since 1991 Mexico has been involved in this pandemia. Near 20% of all cases of cholera in our country happen in fertile women, so the possibility of the association between cholera and pregnancy is high. We present the case of a pregnant woman, who during her third trimester presented a episode of cholera, developing premature labor. Furthermore is revised the medical literature about the general principles of the management of cholera, and the association between pregnancy and the intestinal infection.

  10. [Seroepidemiology of cholera in Mexico].

    Science.gov (United States)

    González-Bonilla, C; Valle-Valdez, J G; Núñez-León, A; Moguel-Pech, L; Villanueva-Zamudio, A

    1994-01-01

    Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera. Samples from their contacts and from healthy people living in the same communities were also analyzed. Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples. An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera. Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year.

  11. [Performance of Cholera-SMART and Pathogen-Detection-Kit in the quick diagnosis of cholera].

    Science.gov (United States)

    Bolaños, Hilda María; Acuña, María Teresa; Serrano, Ana María; Obando, Xinia; Mairena, Hazel; Cháves, Lorena; Sandí, Flor; Rodríguez, Gina; Tamplin, Mark L; Pérez, Enrique; Campos, Elena

    2004-10-01

    To compare the performance of two rapid systems for the diagnosis of cholera with the culture method, and to propose a strategy for improving the specificity and sensitivity of these systems and reducing the costs involved in making a diagnosis. The following institutions participated in the study: the National Bacteriology Referral Center (Centro Nacional de Referencia en Bacteriologia, CNRB) of the Costa Rican Institute for Research and Teaching in Nutrition and Health (Instituto Costarricense de Investigacion y Ensenanza en Nutricion y Salud, INCIENSA) and various hospitals in the provinces of Alajuela, Guanacaste and San Jose, in Costa Rica. A total of 237 feces samples were used to asses the performance of two tests for the rapid detection of Vibrio cholerae 01: the Pathogen Detection Kit (PDK, Intelligent Monitoring Systems, Gainesville, Florida, USA) and Cholera-SMART (New Horizons Diagnostics Corp., Columbia, Maryland, USA), both when applied directly (direct SMART and direct PDK) and when applied to specimens cultured in broth-enriched medium for 6 hours (SMART-6 and CPK-6) and for 18 hours (SMART-18 and PDK-18) at 37 degrees C in alkaline peptone water. Liquid and partially formed stools were cultured and examined by means of the rapid direct test; when the initial result was negative, the tests were repeated after culture for periods of 6 and 18 hours. Rectal and fecal swabs were obtained from feces cultured in enriched-broth medium for 6 and 18 hours. In addition, we studied the sensitivity of the rapid testing systems by using pure cultures of V. cholerae 01 (strain SOS-833, CNRB, Costa Rica) that were incubated for 18 to 24 hours, and we assessed the usefulness of observing motility under the microscope in order to rationalize the use of rapid methods. The sensitivity of the direct SMART test and of the direct PDK test was 100% when samples obtained from liquid and partially formed stools and from the intestinal contents of dead bodies were used. With

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

    International Nuclear Information System (INIS)

    Hannan, A.; Humayun, T.; Hussain, M.B.; Yasir, M.; Sikandar, S.

    2010-01-01

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

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

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

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

  14. Cholera in the United States

    Centers for Disease Control (CDC) Podcasts

    2011-11-08

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

  15. How Will Climate Change Impact Cholera Outbreaks?

    Science.gov (United States)

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

    2014-12-01

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

  16. Lipopolysaccharide-specific memory B cell responses to an attenuated live cholera vaccine are associated with protection against Vibrio cholerae infection.

    Science.gov (United States)

    Haney, Douglas J; Lock, Michael D; Gurwith, Marc; Simon, Jakub K; Ishioka, Glenn; Cohen, Mitchell B; Kirkpatrick, Beth D; Lyon, Caroline E; Chen, Wilbur H; Sztein, Marcelo B; Levine, Myron M; Harris, Jason B

    2018-05-11

    The single-dose live attenuated vaccine CVD 103-HgR protects against experimental Vibrio cholerae infection in cholera-naïve adults for at least 6 months after vaccination. While vaccine-induced vibriocidal seroconversion is associated with protection, vibriocidal titers decline rapidly from their peak 1-2 weeks after vaccination. Although vaccine-induced memory B cells (MBCs) might mediate sustained protection in individuals without detectable circulating antibodies, it is unknown whether oral cholera vaccination induces a MBC response. In a study that enrolled North American adults, we measured lipopolysaccharide (LPS)- and cholera toxin (CtxB)-specific MBC responses to PXVX0200 (derived from the CVD 103-HgR strain) and assessed stool volumes following experimental Vibrio cholerae infection. We then evaluated the association between vaccine-induced MBC responses and protection against cholera. There was a significant increase in % CT-specific IgG, % LPS-specific IgG, and % LPS-specific IgA MBCs which persisted 180 days after vaccination as well as a significant association between vaccine-induced increase in % LPS-specific IgA MBCs and lower post-challenge stool volume (r = -0.56, p < 0.001). Oral cholera vaccination induces antigen-specific MBC responses, and the anamnestic LPS-specific responses may contribute to long-term protection and provide correlates of the duration of vaccine-induced protection. NCT01895855. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  17. 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.

  18. 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.

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

    Science.gov (United States)

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

    2016-06-01

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

  20. Antimicrobial drugs for treating cholera

    Science.gov (United States)

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

    2014-01-01

    Background Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. Objectives To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Selection criteria Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Data collection and analysis Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Main results Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43

  1. Deciphering the Origin of the 2012 Cholera Epidemic in Guinea by Integrating Epidemiological and Molecular Analyses

    Science.gov (United States)

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

    2014-01-01

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

  2. Sialic Acid Catabolism Confers a Competitive Advantage to Pathogenic Vibrio cholerae in the Mouse Intestine▿

    Science.gov (United States)

    Almagro-Moreno, Salvador; Boyd, E. Fidelma

    2009-01-01

    Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae ΔnanA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment. PMID:19564383

  3. Sialic acid catabolism confers a competitive advantage to pathogenic vibrio cholerae in the mouse intestine.

    Science.gov (United States)

    Almagro-Moreno, Salvador; Boyd, E Fidelma

    2009-09-01

    Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae DeltananA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment.

  4. Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016

    OpenAIRE

    Bwire, Godfrey; Ali, Mohammad; Sack, David A.; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K.; Ngwa, Moise C.; Brooks, W. Abdullah; Garimoi Orach, Christopher

    2017-01-01

    Background Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. Methodology/Principle findings We obtained district level confirmed cholera outbreak data from 2011 t...

  5. Small farmers and deforestation in Amazonia

    Science.gov (United States)

    Brondízio, Eduardo S.; Cak, Anthony; Caldas, Marcellus M.; Mena, Carlos; Bilsborrow, Richard; Futemma, Celia T.; Ludewigs, Thomas; Moran, Emilio F.; Batistella, Mateus

    This chapter discusses the relationship between small farmers' land use and deforestation, with particular attention paid to the past 30 years of Amazonian colonization in Brazil and Ecuador. Our analysis calls attention to common features uniting different social groups as small farmers (e.g., social identity, access to land and resources, technology, market, and credit), as well as the variability between small farmers in terms of time in the region (from native populations to recent colonists), contribution to regional deforestation, types of land use systems. At a regional level, small farmers contribute to the majority of deforestation events, but are responsible for only a fraction of the total deforested area in Amazonia. We discuss three misconceptions that have been used to define small farmers and their contribution to the regional economy, development, and deforestation: (1) small farmers have backward land use systems associated with low productivity and extensive deforestation and subsistence production, (2) small farmers contribute to Amazonian deforestation as much as large farmers, and (3) small farmers, particularly colonist farmers, follow an inexorable path of deforestation unless curbed by government action. We conclude the chapter discussing their growing regional importance and the need for more inclusive public policies concerning infrastructure and services and valorization of resources produced in rural areas of Amazonia.

  6. A simple and convenient microtiter plate assay for the detection of bactericidal antibodies to Vibrio cholerae O1 and Vibrio cholerae O139.

    Science.gov (United States)

    Boutonnier, Alain; Dassy, Bruno; Duménil, Rémy; Guénolé, Alain; Ratsitorahina, Maherisoa; Migliani, René; Fournier, Jean-Michel

    2003-12-01

    It is believed that the correlate of protection for cholera can be determined by the serum vibriocidal assay. The currently available vibriocidal assays, based on the conventional agar plating technique, are labor intensive. We developed a simple and convenient microtiter plate assay for the detection of vibriocidal antibodies that is equally as efficient for Vibrio cholerae O1 and for V. cholerae O139. The addition of succinate and neotetrazolium made it possible to measure the growth of surviving bacterial target cells by monitoring a color change. We evaluated assay parameters (target strains, growth of target cells, complement source and concentration) that may affect the reproducibility of the method for V. cholerae O139. The results obtained with the microtiter plate assay were uniformly similar to those obtained with the conventional agar plating assay, when testing both the Inaba and Ogawa serotypes of V. cholerae O1. The microtiter plate assay was also convenient for measuring the activity of animal sera and mouse monoclonal antibodies.

  7. Evaluation of a highly discriminating multiplex multi-locus variable-number of tandem-repeats (MLVA) analysis for Vibrio cholerae.

    Science.gov (United States)

    Olsen, Jaran S; Aarskaug, Tone; Skogan, Gunnar; Fykse, Else Marie; Ellingsen, Anette Bauer; Blatny, Janet M

    2009-09-01

    Vibrio cholerae is the etiological agent of cholera and may be used in bioterror actions due to the easiness of its dissemination, and the public fear for acquiring the cholera disease. A simple and highly discriminating method for connecting clinical and environmental isolates of V. cholerae is needed in microbial forensics. Twelve different loci containing variable numbers of tandem-repeats (VNTRs) were evaluated in which six loci were polymorphic. Two multiplex reactions containing PCR primers targeting these six VNTRs resulted in successful DNA amplification of 142 various environmental and clinical V. cholerae isolates. The genetic distribution inside the V. cholerae strain collection was used to evaluate the discriminating power (Simpsons Diversity Index=0.99) of this new MLVA analysis, showing that the assay have a potential to differentiate between various strains, but also to identify those isolates which are collected from a common V. cholerae outbreak. This work has established a rapid and highly discriminating MLVA assay useful for track back analyses and/or forensic studies of V. cholerae infections.

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

    Science.gov (United States)

    Holmgren, Jan

    1981-07-01

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

  9. 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

  10. Neogene climate evolution in Amazonia and the Brazilian Northeast

    NARCIS (Netherlands)

    Hoorn, C.; Bernardes-de-Oliveira, M.E.C.; Dino, R.; Garcia, M.J.; Antonioli, L.; da Costa Casado, F.; Hooghiemstra, H.; de Souza Carvalho, I.; Garcia, M.J.; Strohschoen, O.; Cunha Lana, C.

    2014-01-01

    Climate change follows from the interaction between global atmospheric and oceanic processes with regional processes. In this chapter we review which factors determined climate evolution in Amazonia and the Brazilian Northeast and present a recompilation of Neogene palynological and paleobotanical

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

    Directory of Open Access Journals (Sweden)

    Racheal W. Kimani

    2014-10-01

    Objectives: The objectives of the study were to determine the environmental reservoirs of V. cholerae during an interepidemic period in Kenya and to characterise their virulence factors. Methods: One hundred (50 clinical, 50 environmental samples were tested for V. cholerae isolates using both simplex and multiplex polymerase chain reaction. Results: Both sediments and algae from fishing and landing bays yielded isolates of V. cholerae. Clinical strains were characterised along with the environmental strains for comparison. All clinical strains harboured ctxA, tcpA (El Tor, ompU, zot, ace, toxR, hylA (El Tor and tcpI genes. Prevalence for virulence genes in environmental strains was hylA (El Tor (10%, toxR (24%, zot (22%, ctxA (12%,tcpI (8%, hylA (26% and tcpA (12%. Conclusion: The study sites, including landing bays and beaches, contained environmental V. cholerae, suggesting that these may be reservoirs for frequent epidemics. Improved hygiene and fish-handling techniques will be important in reducing the persistence of reservoirs.

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

    Science.gov (United States)

    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

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

    OpenAIRE

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

    1998-01-01

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

  14. Carbon stock loss from deforestation through 2013 in Brazilian Amazonia.

    Science.gov (United States)

    Nogueira, Euler Melo; Yanai, Aurora M; Fonseca, Frederico O R; Fearnside, Philip Martin

    2015-03-01

    The largest carbon stock in tropical vegetation is in Brazilian Amazonia. In this ~5 million km(2) area, over 750,000 km(2) of forest and ~240,000 km(2) of nonforest vegetation types had been cleared through 2013. We estimate current carbon stocks and cumulative gross carbon loss from clearing of premodern vegetation in Brazil's 'Legal Amazonia' and 'Amazonia biome' regions. Biomass of 'premodern' vegetation (prior to major increases in disturbance beginning in the 1970s) was estimated by matching vegetation classes mapped at a scale of 1 : 250,000 and 29 biomass means from 41 published studies for vegetation types classified as forest (2317 1-ha plots) and as either nonforest or contact zones (1830 plots and subplots of varied size). Total biomass (above and below-ground, dry weight) underwent a gross reduction of 18.3% in Legal Amazonia (13.1 Pg C) and 16.7% in the Amazonia biome (11.2 Pg C) through 2013, excluding carbon loss from the effects of fragmentation, selective logging, fires, mortality induced by recent droughts and clearing of forest regrowth. In spite of the loss of carbon from clearing, large amounts of carbon were stored in stands of remaining vegetation in 2013, equivalent to 149 Mg C ha(-1) when weighted by the total area covered by each vegetation type in Legal Amazonia. Native vegetation in Legal Amazonia in 2013 originally contained 58.6 Pg C, while that in the Amazonia biome contained 56 Pg C. Emissions per unit area from clearing could potentially be larger in the future because previously cleared areas were mainly covered by vegetation with lower mean biomass than the remaining vegetation. Estimates of original biomass are essential for estimating losses to forest degradation. This study offers estimates of cumulative biomass loss, as well as estimates of premodern carbon stocks that have not been represented in recent estimates of deforestation impacts. © 2014 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2014-12-23

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

  16. Pre-Columbian Earthworks in Coastal Amazonia

    Directory of Open Access Journals (Sweden)

    Stéphen Rostain

    2010-03-01

    Full Text Available As in other parts of Amazonia, pre-Columbian Indians have profoundly modified the coast of the Guianas. Between 650 and 1650 AD, Arauquinoid people occupied a territory that was approximately 600 km long and used the raised field technique intensively before the European conquest. They erected thousands of raised fields of various shapes, dug canals, ditches, and pathways, and built artificial mounds to establish their villages. All these earthworks changed forever the face of the coastal flooded savannas and their ecology. Such labor was probably organized under the leadership of a central authority: it seems that Arauquinoid societies were organized in a chiefdom system. Statistical calculations, based on the known surface area of raised fields and on their estimated productivity, suggest a population density of 50 to 100 inhabitants per km2. Pre-Columbian inhabitants of the Guianas coast carefully organized, managed and “anthropisized” their territory following a specific pattern.

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

    Science.gov (United States)

    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

  18. Within-canopy sesquiterpene ozonolysis in Amazonia

    Science.gov (United States)

    Jardine, K.; YañEz Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; van Haren, J.; Artaxo, P.; Rizzo, L. V.; Ishida, F. Y.; Karl, T.; Kesselmeier, J.; Saleska, S.; Huxman, T.

    2011-10-01

    Through rapid reactions with ozone, which can initiate the formation of secondary organic aerosols, the emission of sesquiterpenes from vegetation in Amazonia may have significant impacts on tropospheric chemistry and climate. Little is known, however, about sesquiterpene emissions, transport, and chemistry within plant canopies owing to analytical difficulties stemming from very low ambient concentrations, high reactivities, and sampling losses. Here, we present ambient sesquiterpene concentration measurements obtained during the 2010 dry season within and above a primary tropical forest canopy in Amazonia. We show that by peaking at night instead of during the day, and near the ground instead of within the canopy, sesquiterpene concentrations followed a pattern different from that of monoterpenes, suggesting that unlike monoterpene emissions, which are mainly light dependent, sesquiterpene emissions are mainly temperature dependent. In addition, we observed that sesquiterpene concentrations were inversely related with ozone (with respect to time of day and vertical concentration), suggesting that ambient concentrations are highly sensitive to ozone. These conclusions are supported by experiments in a tropical rain forest mesocosm, where little atmospheric oxidation occurs and sesquiterpene and monoterpene concentrations followed similar diurnal patterns. We estimate that the daytime dry season ozone flux of -0.6 to -1.5 nmol m-2 s-1 due to in-canopy sesquiterpene reactivity could account for 7%-28% of the net ozone flux. Our study provides experimental evidence that a large fraction of total plant sesquiterpene emissions (46%-61% by mass) undergo within-canopy ozonolysis, which may benefit plants by reducing ozone uptake and its associated oxidative damage.

  19. Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016.

    Science.gov (United States)

    Bwire, Godfrey; Ali, Mohammad; Sack, David A; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K; Ngwa, Moise C; Brooks, W Abdullah; Garimoi Orach, Christopher

    2017-12-01

    Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. We obtained district level confirmed cholera outbreak data from 2011 to 2016 from the Ministry of Health, Uganda. Population and rainfall data were obtained from the Uganda Bureau of Statistics, and water, sanitation and hygiene data from the Ministry of Water and Environment. A spatial scan test was performed to identify the significantly high risk clusters. Cholera hotspots were defined as districts whose center fell within a significantly high risk cluster or where a significantly high risk cluster was completely superimposed onto a district. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. In total 11,030 cases of cholera were reported during the 6-year period. 37(33%) of 112 districts reported cholera outbreaks in one of the six years, and 20 (18%) districts experienced cholera at least twice in those years. We identified 22 districts as high risk for cholera, of which 13 were near a border of Democratic Republic of Congo (DRC), while 9 districts were near a border of Kenya. The relative risk of having cholera inside the high-risk districts (hotspots) were 2 to 22 times higher than elsewhere in the country. In total, 7 million people were within cholera hotspots. The negative binomial component of the ZINB model shows people living near a lake or the Nile river were at increased risk for cholera (incidence rate ratio, IRR = 0.98, 95% CI: 0.97 to 0.99, p cholera in a district (IRR = 0.99, 95% CI: 0.98 to 1.00, p = .02 and IRR = 1.02, 95% CI: 1.01 to 1.03, p cholera in the district. The study identified cholera

  20. DksA-HapR-RpoS axis regulates haemagglutinin protease production in Vibrio cholerae.

    Science.gov (United States)

    Basu, Pallabi; Pal, Ritesh Ranjan; Dasgupta, Shreya; Bhadra, Rupak K

    2017-06-01

    DksA acts as a co-factor for the intracellular small signalling molecule ppGpp during the stringent response. We recently reported that the expression of the haemagglutinin protease (HAP), which is needed for shedding of the cholera pathogen Vibrio cholerae during the late phase of infection, is significantly downregulated in V. cholerae ∆dksA mutant (∆dksAVc) cells. So far, it has been shown that HAP production by V. cholerae cells is critically regulated by HapR and also by RpoS. Here, we provide evidence that V. cholerae DksA (DksAVc) positively regulates HapR at both the transcriptional and post-transcriptional levels. We show that in ∆dksAVc cells the CsrB/C/D sRNAs, required for the maintenance of intracellular levels of hapR transcripts during the stationary growth, are distinctly downregulated. Moreover, the expression of exponential phase regulatory protein Fis, a known negative regulator of HapR, was found to continue even during the stationary phase in ∆dksAVc cells compared to that of wild-type strain, suggesting another layer of complex regulation of HapR by DksAVc. Extensive reporter construct-based and quantitative reverse-transcriptase PCR (qRT-PCR) analyses supported that RpoS is distinctly downregulated at the post-transcriptional/translational levels in stationary phase-grown ∆dksAVc cells. Since HAP expression through HapR and RpoS is stationary phase-specific in V. cholerae, it appears that DksAVc is also a critical stationary phase regulator for fine tuning of the expression of HAP. Moreover, experimental evidence provided in this study clearly supports that DksAVc is sitting at the top of the hierarchy of regulation of expression of HAP in V. cholerae.

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

    Science.gov (United States)

    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

  2. Twee Nederlandse reizigers uit Thailand met cholera

    NARCIS (Netherlands)

    Smit, A. A.; Kuijper, E. J.; Schultz, M. J.; Wieling, W.; Speelman, P.

    1994-01-01

    Cholera is a disease rarely imported in the Netherlands. Recently a 34-year-old woman who had returned from a trip through Thailand was admitted to our hospital with complaints of vomiting, watery stools and moderate dehydration. Vibrio cholerae OI serotype Ogawa biotype El Tor was isolated from the

  3. High case fatality cholera outbreak in Western Kenya, August 2010 ...

    African Journals Online (AJOL)

    Introduction: Cholera is a disease caused by the bacterium Vibrio cholera and has been an important public health problem since its first pandemic in 1817. Kenya has had numerous outbreaks of cholera ever since it was first detected there during 1971. In August 2010 an outbreak of cholera occurred in Kuria West District ...

  4. High case fatality cholera outbreak in Western Kenya, August 2010

    African Journals Online (AJOL)

    abp

    Abstract. Introduction: Cholera is a disease caused by the bacterium Vibrio cholera and has been an important public health problem since its first pandemic in 1817. Kenya has had numerous outbreaks of cholera ever since it was first detected there during 1971. In August 2010 an outbreak of cholera occurred in Kuria ...

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

    International Nuclear Information System (INIS)

    Palit, B.N.; Das, G.; Das, J.

    1983-01-01

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

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

    Science.gov (United States)

    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.

  7. Crystallization of isoelectrically homogeneous cholera toxin

    International Nuclear Information System (INIS)

    Spangler, B.D.; Westbrook, E.M.

    1989-01-01

    Past difficulty in growing good crystals of cholera toxin has prevented the study of the crystal structure of this important protein. The authors have determined that failure of cholera toxin to crystallize well has been due to its heterogeneity. They have now succeeded in overcoming the problem by isolating a single isoelectric variant of this oligomeric protein (one A subunit and five B subunits). Cholera toxin purified by their procedure readily forms large single crystals. The crystal form has been described previously. They have recorded data from native crystals of cholera toxin to 3.0-angstrom resolution with our electronic area detectors. With these data, they have found the orientation of a 5-fold symmetry axis within these crystals, perpendicular to the screw dyad of the crystal. They are now determining the crystal structure of cholera toxin by a combination of multiple heavy-atom isomorphous replacement and density modification techniques, making use of rotational 5-fold averaging of the B subunits

  8. 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

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

    Science.gov (United States)

    Sánchez, Eduardo; García, Santos; Heredia, Norma

    2010-10-01

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

  10. On the Relationship of Rainfall and Temperature across Amazonia

    Science.gov (United States)

    Ribeiro Lima, C. H.; AghaKouchak, A.

    2017-12-01

    Extreme droughts in Amazonia seem to become more frequent and have been associated with local and global impacts on society and the ecosystem. The understanding of the dynamics and causes of Amazonia droughts have attracted some attention in the last years and pose several challenges for the scientific community. For instance, in previous work we have identified, based on empirical data, a compounding effect during Amazonia droughts: periods of low rainfall are always associated with positive anomalies of near surface air temperature. This inverse relationship of temperature and rainfall appears at multiple time scales and its intensity varies across Amazonia. To our knowledge, these findings have not been properly addressed in the literature, being not clear whether there is a causal relationship between these two variables, and in this case, which one leads the other one, or they are just responding to the same causal factor. Here we investigate the hypothesis that high temperatures during drought periods are a major response to an increase in the shortwave radiation (due to the lack of clouds) not compensating by an expected increase in the evapotranspiration from the rainforest. Our empirical analysis is based on observed series of daily temperature and rainfall over the Brazilian Amazonia and reanalysis data of cloud cover, outgoing longwave radiation (OLR) and moisture fluxes. The ability of Global Circulation Models (GCMs) to reproduce such compounding effect is also investigated for the historical period and for future RCP scenarios of global climate change. Preliminary results show that this is a plausible hypothesis, despite the complexity of land-atmosphere processes of mass and energy fluxes in Amazonia. This work is a step forward in better understanding the compounding effects of rainfall and temperature on Amazonia droughts, and what changes one might expect in a future warming climate.

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

    Science.gov (United States)

    Sealfon, Rachel; Gire, Stephen; Ellis, Crystal; Calderwood, Stephen; Qadri, Firdausi; Hensley, Lisa; Kellis, Manolis; Ryan, Edward T; LaRocque, Regina C; Harris, Jason B; Sabeti, Pardis C

    2012-09-11

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

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

    Directory of Open Access Journals (Sweden)

    Sealfon Rachel

    2012-09-01

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

  13. The Large-Scale Biosphere-Atmosphere Experiment in Amazonia: Analyzing Regional Land Use Change Effects.

    Science.gov (United States)

    Michael Keller; Maria Assunção Silva-Dias; Daniel C. Nepstad; Meinrat O. Andreae

    2004-01-01

    The Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multi-disciplinary, multinational scientific project led by Brazil. LBA researchers seek to understand Amazonia in its global context especially with regard to regional and global climate. Current development activities in Amazonia including deforestation, logging, cattle ranching, and agriculture...

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

    Science.gov (United States)

    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.

  15. Antimicrobial drugs for treating cholera.

    Science.gov (United States)

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

    2014-06-19

    Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43.51 to -30.03, 19 trials, 1013 participants, moderate quality evidence). Antimicrobial therapy also

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

    Directory of Open Access Journals (Sweden)

    Shuchismita Dey

    2014-01-01

    Full Text Available Background & objectives: Successive outbreaks of acute watery diarrhoea occurred in Talikoti and Harnal, located in Bijapur District of the southern Indian s0 tate of Karnataka, in July and August 2012, respectively. These outbreaks were investigated to identify the aetiology and epidemiology. Methods: Information was collected from the local population and health centres. Stool and water samples were collected from the admitted patients and their drinking water sources. Standard microbiological and PCR techniques were employed for isolation and characterization of the pathogen. Results: While 101 people (0.38% were affected in Talikoti, 200 (20.94% were affected in Harnal which is a small remote village. All age groups were affected but no death occurred. While the outbreak was smaller, longer and apparently spread by person to person contact in Talikoti, it occurred as a single source flash outbreak at Harnal. A single clone of toxigenic Vibrio cholerae O1 Ogawa biotype El Tor was isolated from the two stool samples obtained from Talikoti and subsequently from three of five stool samples obtained from Harnal indicating village to village spread of the aetiological agent. Striking similarity in antibiotic resistance profiles of these isolates with a particular strain isolated from the city of Belgaum, 250 km away, in 2010, prompted tracking the lineage of the V. cholerae isolates by DNA fingerprinting. Random amplified polymorphic DNA (RAPD fingerprinting assay helped confirm the origin of the incriminating strain to Belgaum. Interpretation & conclusions: Our study reported the first twin outbreak of cholera in two remote areas of Bijapur district, Karnataka, south India. It also indicated the need for immediate preparedness to deal with such emergencies.

  17. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

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

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...

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

    Science.gov (United States)

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

    2016-09-01

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

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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

  1. Epidemic risk from cholera introductions into Mexico.

    Science.gov (United States)

    Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

    2014-02-21

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

  2. The Burden of Cholera in Uganda

    Science.gov (United States)

    Bwire, Godfrey; Malimbo, Mugagga; Maskery, Brian; Kim, Young Eun; Mogasale, Vittal; Levin, Ann

    2013-01-01

    Introduction In 2010, the World Health Organization released a new cholera vaccine position paper, which recommended the use of cholera vaccines in high-risk endemic areas. However, there is a paucity of data on the burden of cholera in endemic countries. This article reviewed available cholera surveillance data from Uganda and assessed the sufficiency of these data to inform country-specific strategies for cholera vaccination. Methods The Uganda Ministry of Health conducts cholera surveillance to guide cholera outbreak control activities. This includes reporting the number of cases based on a standardized clinical definition plus systematic laboratory testing of stool samples from suspected cases at the outset and conclusion of outbreaks. This retrospective study analyzes available data by district and by age to estimate incidence rates. Since surveillance activities focus on more severe hospitalized cases and deaths, a sensitivity analysis was conducted to estimate the number of non-severe cases and unrecognized deaths that may not have been captured. Results Cholera affected all ages, but the geographic distribution of the disease was very heterogeneous in Uganda. We estimated that an average of about 11,000 cholera cases occurred in Uganda each year, which led to approximately 61–182 deaths. The majority of these cases (81%) occurred in a relatively small number of districts comprising just 24% of Uganda's total population. These districts included rural areas bordering the Democratic Republic of Congo, South Sudan, and Kenya as well as the slums of Kampala city. When outbreaks occurred, the average duration was about 15 weeks with a range of 4–44 weeks. Discussion There is a clear subdivision between high-risk and low-risk districts in Uganda. Vaccination efforts should be focused on the high-risk population. However, enhanced or sentinel surveillance activities should be undertaken to better quantify the endemic disease burden and high-risk populations

  3. 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.

  4. Microbial glycolipoprotein-capped silver nanoparticles as emerging antibacterial agents against cholera.

    Science.gov (United States)

    Gahlawat, Geeta; Shikha, Sristy; Chaddha, Baldev Singh; Chaudhuri, Saumya Ray; Mayilraj, Shanmugam; Choudhury, Anirban Roy

    2016-02-01

    With the increased number of cholera outbreaks and emergence of multidrug resistance in Vibrio cholerae strains it has become necessary for the scientific community to devise and develop novel therapeutic approaches against cholera. Recent studies have indicated plausibility of therapeutic application of metal nano-materials. Among these, silver nanoparticles (AgNPs) have emerged as a potential antimicrobial agent to combat infectious diseases. At present nanoparticles are mostly produced using physical or chemical techniques which are toxic and hazardous. Thus exploitation of microbial systems could be a green eco-friendly approach for the synthesis of nanoparticles having similar or even better antimicrobial activity and biocompatibility. Hence, it would be worth to explore the possibility of utilization of microbial silver nanoparticles and their conjugates as potential novel therapeutic agent against infectious diseases like cholera. The present study attempted utilization of Ochrobactrum rhizosphaerae for the production of AgNPs and focused on investigating their role as antimicrobial agents against cholera. Later the exopolymer, purified from the culture supernatant, was used for the synthesis of spherical shaped AgNPs of around 10 nm size. Further the exopolymer was characterized as glycolipoprotein (GLP). Antibacterial activity of the novel GLP-AgNPs conjugate was evaluated by minimum inhibitory concentration, XTT reduction assay, scanning electron microscopy (SEM) and growth curve analysis. SEM studies revealed that AgNPs treatment resulted in intracellular contents leakage and cell lysis. The potential of microbially synthesized nanoparticles, as novel therapeutic agents, is still relatively less explored. In fact, the present study first time demonstrated that a glycolipoprotein secreted by the O. rhizosphaerae strain can be exploited for production of AgNPs which can further be employed to treat infectious diseases. Although this type of polymer has

  5. Impact of oral cholera vaccines in cholera-endemic countries: A mathematical modeling study.

    Science.gov (United States)

    Kim, Jong-Hoon; Mogasale, Vittal; Burgess, Colleen; Wierzba, Thomas F

    2016-04-19

    Impact evaluation of vaccination programs is necessary for making decisions to introduce oral cholera vaccines (OCVs) in cholera-endemic countries. We analyzed data to forecast the future global burden of cholera. We developed a mathematical model of cholera transmission in three countries as examples: Nigeria, Uganda, and Indonesia. After fitting the model, we evaluated the impact of OCVs delivered in four vaccination strategies varying by target age group and frequency of vaccination over the period of 2015-2030. Data suggest that the global annual incidence of cholera will increase from 3046238 in 2015 to 3787385 in 2030 with the highest burden in Asia and Africa where overall population size is large and the proportion of population with access to improved sanitation facilities is low. We estimate that OCV will reduce the cumulative incidence of cholera by half in Indonesia and >80% in Nigeria and Uganda when delivered to 1+ year olds every three years at a coverage rate of 50%, although cholera may persist through higher coverage rates (i.e., >90%). The proportion of person-to-person transmission compared to water-to-person transmission is positively correlated with higher vaccination impact in all three countries. Periodic OCV vaccination every three or five years can significantly reduce the global burden of cholera although cholera may persist even with high OCV coverage. Vaccination impact will likely vary depending on local epidemiological conditions including age distribution of cases and relative contribution of different transmission routes. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Barkha Khilwani

    2015-08-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Biogeochemistry and ecology of terrestrial ecosystems of Amazonia

    Science.gov (United States)

    Malhi, Yadvinder; Davidson, Eric A.

    The last decade of research associated with the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) has led to substantial advances in our understanding of the biogeochemistry and ecology of Amazonian forests and savannas, in particular in relation to the carbon cycle of Amazonia. In this chapter, we present a synthesis of results and ideas that are presented in more detail in subsequent chapters, drawing together evidence from studies of forest ecology, ecophysiology, trace gas fluxes and atmospheric flux towers, large-scale rainfall manipulation experiments and soil surveys, satellite remote sensing, and quantification of carbon and nutrient stocks and flows. The studies have demonstrated the variability of the functioning and biogeochemistry of Amazonian forests at a range of spatial and temporal scales, and they provide clues as to how Amazonia will respond to ongoing direct pressure and global atmospheric change. We conclude by highlighting key questions for the next decade of research to address.

  9. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. IV. Alopoglossidae, Gymnophthalmidae.

    Science.gov (United States)

    Ribeiro-Júnior, Marco A; Amaral, Silvana

    2017-05-22

    We present distribution data of all Alopoglossidae and Gymnophthalmidae lizards known from the Brazilian Amazonia, totaling 54 species-level taxa, belonging to 17 genera and two families. This represents 22 more species-level taxa than previously reported. Data were based on 17,431 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~80%) are endemic to Amazonia; non-endemic species are mainly associated with open vegetation (savanna) enclaves or open dry (semideciduous) forest in Amazonia, with a few exceptions. As a whole, seven taxa (including one species complex) are widespread in Amazonia, six are restricted to eastern Amazonia, seven to western Amazonia, two to southwestern Amazonia, 11 to southern Amazonia, 11 to northern Amazonia (either in part of it or widespread in the Guiana region), and six to the southern peripheral portion of Amazonia. Besides, four species present unique distributions. Considering this study and the other three catalogues of distribution of lizards already published, the total number of lizard species from Brazilian Amazonia increased from 97 to 142 species-level tava. It represents an increase of 45 species from the region since the last revision.

  10. Dynamics, patterns and causes of fires in Northwestern Amazonia.

    Science.gov (United States)

    Armenteras, Dolors; Retana, Javier

    2012-01-01

    According to recent studies, two widespread droughts occurred in the Amazon basin, one during 2005 and one during 2010. The drought increased the prevalence of climate-driven fires over most of the basin. Given the importance of human-atmosphere-vegetation interactions in tropical rainforests, these events have generated concerns over the vulnerability of this area to climate change. This paper focuses on one of the wettest areas of the basin, Northwestern Amazonia, where the interactions between the climate and fires are much weaker and where little is known about the anthropogenic drivers of fires. We have assessed the response of fires to climate over a ten-year period, and analysed the socio-economic and demographic determinants of fire occurrence. The patterns of fires and climate and their linkages in Northwestern Amazonia differ from the enhanced fire response to climate variation observed in the rest of Amazonia. The highest number of recorded fires in Northwestern Amazonia occurred in 2004 and 2007, and this did not coincide with the periods of extreme drought experienced in Amazonia in 2005 and 2010. Rather, during those years, Northwestern Amazonia experienced a relatively small numbers of fire hotspots. We have shown that fire occurrence correlated well with deforestation and was determined by anthropogenic drivers, mainly small-scale agriculture, cattle ranching (i.e., pastures) and active agricultural frontiers (including illegal crops). Thus, the particular climatic conditions for air convergence and rainfall created by proximity to the Andes, coupled with the presence of one of the most active colonisation fronts in the region, make this region differently affected by the general drought-induced fire patterns experienced by the rest of the Amazon. Moreover, the results suggest that, even in this wet region, humans are able to modify the frequency of fires and impact these historically well preserved forests.

  11. The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus

    Directory of Open Access Journals (Sweden)

    James L Crainey

    2016-01-01

    Full Text Available We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource.

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

    Directory of Open Access Journals (Sweden)

    Erika Acosta-Smith

    2018-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  14. Misidentification of Vibrio cholerae O155 isolated from imported shrimp as O serogroup O139 due to cross-agglutination with commercial O139 antisera

    DEFF Research Database (Denmark)

    Dalsgaard, A.; Mazur, J.; Dalsgaard, Inger

    2002-01-01

    . The strain contained two plasmids, in contrast to other O139 strains, which normally do not contain plasmids. The characteristics of the strain led to further agglutination testing with other antisera that are not commercially available, and the strain was found to agglutinate O155 antiserum in repeated...... was isolated from imported raw frozen shrimp. The toxigenicity of the strain was analyzed, and the results of a polymerase chain reaction showed that the V. cholerae strain did not contain the virulence genes ctx, tcp9, and zot, which are normally found in V. cholerae O1 and O139. The strain was resistant...... to colistin and spectinomycin. The high susceptibility of the strain to antimicrobial agents was confirmed by the lack of an SXT element, a self-transmissible, chromosomal genetic element that is normally present in O139 strains and encodes resistance to sulfonamides, trimethoprim, and streptomycin...

  15. EPIDEMIOLOGY OF CHOLERA OUTBREAK IN KAMPALA ...

    African Journals Online (AJOL)

    hi-tech

    77 No. 7 July 2000. EPIDEMIOLOGY OF CHOLERA OUTBREAK IN KAMPALA, UGANDA ... spread much (106 cases in 1995), resulting in a low level of immunity ... An intensive social ... development of a network of community health workers,.

  16. Influence of human behavior on cholera dynamics.

    Science.gov (United States)

    Wang, Xueying; Gao, Daozhou; Wang, Jin

    2015-09-01

    This paper is devoted to studying the impact of human behavior on cholera infection. We start with a cholera ordinary differential equation (ODE) model that incorporates human behavior via modeling disease prevalence dependent contact rates for direct and indirect transmissions and infectious host shedding. Local and global dynamics of the model are analyzed with respect to the basic reproduction number. We then extend the ODE model to a reaction-convection-diffusion partial differential equation (PDE) model that accounts for the movement of both human hosts and bacteria. Particularly, we investigate the cholera spreading speed by analyzing the traveling wave solutions of the PDE model, and disease threshold dynamics by numerically evaluating the basic reproduction number of the PDE model. Our results show that human behavior can reduce (a) the endemic and epidemic levels, (b) cholera spreading speeds and (c) the risk of infection (characterized by the basic reproduction number). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Intestinal Colonization Dynamics of Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Salvador Almagro-Moreno

    2015-05-01

    Full Text Available To cause the diarrheal disease cholera, Vibrio cholerae must effectively colonize the small intestine. In order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. The bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. In this review, we discuss recent developments and known aspects of the early stages of V. cholerae intestinal colonization and highlight areas that remain to be fully understood. We propose mechanisms and postulate a model that covers some of the steps that are required in order for the bacterium to efficiently colonize the human host. A deeper understanding of the colonization dynamics of V. cholerae and other intestinal pathogens will provide us with a variety of novel targets and strategies to avoid the diseases caused by these organisms.

  18. Costs of Illness Due to Endemic Cholera

    Science.gov (United States)

    Poulos, C.; Riewpaiboon, A.; Stewart, J.F.; Clemens, J.; Guh, S.; Agtini, M.; Sur, D.; Islam, Z.; Lucas, M.; Whittington, D.

    2013-01-01

    Summary Economic analyses of cholera immunization programmes require estimates of the costs of cholera. The Diseases of the Most Impoverished programme measured the public, provider, and patient costs of culture-confirmed cholera in four study sites with endemic cholera using a combination of hospital- and community-based studies. Families with culture-proven cases were surveyed at home 7 and 14 days after confirmation of illness. Public costs were measured at local health facilities using a micro-costing methodology. Hospital-based studies found that the costs of severe cholera were USD 32 and 47 in Matlab and Beira. Community-based studies in North Jakarta and Kolkata found that cholera cases cost between USD 28 and USD 206, depending on hospitalization. Patient costs of illness as a percentage of average monthly income were 21% and 65% for hospitalized cases in Kolkata and North Jakarta, respectively. This burden on families is not captured by studies that adopt a provider perspective. PMID:21554781

  19. BIOFILM FORMATION OF Vibrio cholerae ON STAINLESS STEEL USED IN FOOD PROCESSING

    Directory of Open Access Journals (Sweden)

    Milagro FERNÁNDEZ-DELGADO

    2016-01-01

    Full Text Available Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM. Results showed no cell adhesion at 4 h and scarce surface colonization at 24 h. Biofilms from the environmental strain were observed at 48 h with high cellular aggregations embedded in Vibrio exopolysaccharide (VPS, while less confluence and VPS production with microcolonies of elongated cells were observed in biofilms produced by the clinical strain. At 96 h the biofilms of the environmental strain were released from the surface leaving coccoid cells and residual structures, whereas biofilms of the clinical strain formed highly organized structures such as channels, mushroom-like and pillars. This is the first study that has shown the in vitro ability of V. cholerae to colonize and form biofilms on stainless steel used in food processing.

  20. BIOFILM FORMATION OF Vibrio cholerae ON STAINLESS STEEL USED IN FOOD PROCESSING.

    Science.gov (United States)

    Fernández-Delgado, Milagro; Rojas, Héctor; Duque, Zoilabet; Suárez, Paula; Contreras, Monica; García-Amado, M Alexandra; Alciaturi, Carlos

    2016-01-01

    Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM). Results showed no cell adhesion at 4 h and scarce surface colonization at 24 h. Biofilms from the environmental strain were observed at 48 h with high cellular aggregations embedded in Vibrio exopolysaccharide (VPS), while less confluence and VPS production with microcolonies of elongated cells were observed in biofilms produced by the clinical strain. At 96 h the biofilms of the environmental strain were released from the surface leaving coccoid cells and residual structures, whereas biofilms of the clinical strain formed highly organized structures such as channels, mushroom-like and pillars. This is the first study that has shown the in vitro ability of V. cholerae to colonize and form biofilms on stainless steel used in food processing.

  1. Astrocaryum (palmae in Amazonia a preliminary treatment

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available ASTROCARYUM (PALMAE EN AMAZONIE. TRAITEMENT PRÉLIMINAIRE. Le genre Astrocaryum est composé de 24 espèces amazoniennes: cinq appartiennent au sous-genre Pleiogynanthus et 19 au sous-genre Monogynanthus (3 à la section Munbaca et 16 à la section Ayri. Une clé d’identification est proposée, ainsi que la description de chaque espèce, complétée par de nouvelles observations et suivie de notes sur la distribution géographique, l’écologie et les utilisations. Six espeses nouvelles sont décrites. ASTROCARYUM (PALMAE EN LA AMAZONIA. TRATAMIENTO PRELIMINAR. Astrocaryum consta de 24 especies amazónicas, 5 de las cuales pertenecen al subgénero Pleiogynanthus y 19 al subgénero Monogynanthus (3 a la sección Munbaca, 16 a la sección Ayri. Se presenta una clave para diferenciar las especies, y para cada una, su descripción con nuevos datos, así como notas sobre la distribución geográfica, la ecología y los usos. Se describen seis especies nuevas. In the Amazon, Astrocaryum includes 24 species of which five belong to the subgenus Pleiogynanthus and 19 to the subgenus Monogynanthus - three in the section Munbaca and 16 in the section Ayri. A key to these 24 species is presented followed by description based on new data, and notes on their distribution, ecology and uses. Six new species are described.

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

    Directory of Open Access Journals (Sweden)

    Fátima Reyes-López

    2015-08-01

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

  3. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. III. Anguidae, Scincidae, Teiidae.

    Science.gov (United States)

    Ribeiro-Júnior, Marco A; Amaral, Silvana

    2016-12-09

    We present distribution data of all Anguidae, Scincidae, and Teiidae lizards known from the Brazilian Amazonia, totaling 29 species-level taxa, belonging to 14 genera. This represents 11 more species-level taxa than previously reported for these families in this area. Data were based on literature and 46,806 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~55%) are endemic to Amazonia. Except for Ameiva ameiva, that is present in several environments and domains, non-endemic species are either associated with open dry (semideciduous) forest or open vegetation (savanna) enclaves in Amazonia, occupying similar environments outside Amazonia, gallery forests within the Cerrado, or present disjunct populations in the Atlantic Forest. As a whole, six taxa are widespread in Amazonia, four are restricted to eastern Amazonia, four to western Amazonia, three to southwestern Amazonia, one to northern Amazonia, and seven to the southern peripheral portion of Amazonia. Besides, two species present apparently more restricted, unique distributions. Only three species have a distribution that is congruent with one of the areas of endemism (AE) recognized for other organisms (birds and primates), of which two occur in AE Guiana and one in AE Inambari.

  4. Paleoclimates of Amazonia: An ice-age view

    NARCIS (Netherlands)

    Bush, M.B.; De Oliveira, P.E.; Raczka, M.F.; Gosling, W.D.; Mayle, F.E.; McMichael, C.H.; Urrego, D.H.; de Souza Carvalho, I.; Garcia, M.J.; Cunha Lana, C.; Strohschoen Jr., O.

    2014-01-01

    A growing body of evidence points to climatic complexity during the Ice-Ages. Amazonia does not respond uniformly to modern climatic forcing, and the same was true of the past. Although some climatic forcings were probably expressed everywhere, they were manifested differently. Consequently, climate

  5. Evapotranspiration of deforested areas in central and southwestern Amazonia

    NARCIS (Netherlands)

    Randow, von R.C.S.; Randow, C.; Hutjes, R.W.A.; Tomasella, J.; Kruijt, B.

    2012-01-01

    Considering the high rates of evapotranspiration of Amazonian forests, understanding the impacts of deforestation on water loss rates is important for assessing those impacts on a regional and global scale. This paper quantifies evapotranspiration rates in two different pasture sites in Amazonia and

  6. Molluscan radiations and landscape evolution in Miocene Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.

    2008-01-01

    This PhD study aims to exploit the rich archive provided by the Miocene mollusc fauna of the Pebas Formation and other inland Miocene Amazonian formations to reconstruct landscape evolution and biotic development in lowland Amazonia during the Neogene. Over 160 samples from more than 70 Pebas

  7. Household Transmission of Vibrio cholerae in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jonathan D Sugimoto

    2014-11-01

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

  8. Global climate and infectious disease: the cholera paradigm.

    Science.gov (United States)

    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.

  9. The case of cholera preparedness, response and prevention in the ...

    African Journals Online (AJOL)

    2011-10-07

    Oct 7, 2011 ... Keywords: Cholera prevention, preparedness and response, socio-political understanding of cholera, socio-cultural understanding .... cies of bacteria or viruses. ... quality such as boiling, chlorination, and filtration are not eco-.

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

    International Nuclear Information System (INIS)

    Das, G.; Sil, K.; Das, J.

    1981-01-01

    Repair of ultraviolet-light-induced DNA damage in a highly pathogenic Gram-negative bacterium, Vibrio cholerae, has been examined. All three strains of V. cholerae belonging to two serotypes, Inaba and Ogawa, are very sensitive to ultraviolet irradiation, having inactivation cross-sections ranging from 0.18 to 0.24 m 2 /J. Although these cells are proficient in repairing the DNA damage by a photoreactivation mechanism, they do not possess efficient dark repair systems. The mild toxinogenic strain 154 of classical Vibrios presumably lacks any excision repair mechanism and studies of irradiated cell DNA indicate that the ultraviolet-induced pyrimidine dimers may not be excised. Ultraviolet-irradiated cells after saturation of dark repair can be further photoreactivated. (Auth.)

  11. Droughts in Amazonia: Spatiotemporal Variability, Teleconnections, and Seasonal Predictions

    Science.gov (United States)

    Lima, Carlos H. R.; AghaKouchak, Amir

    2017-12-01

    Most Amazonia drought studies have focused on rainfall deficits and their impact on river discharges, while the analysis of other important driver variables, such as temperature and soil moisture, has attracted less attention. Here we try to better understand the spatiotemporal dynamics of Amazonia droughts and associated climate teleconnections as characterized by the Palmer Drought Severity Index (PDSI), which integrates information from rainfall deficit, temperature anomalies, and soil moisture capacity. The results reveal that Amazonia droughts are most related to one dominant pattern across the entire region, followed by two seesaw kind of patterns: north-south and east-west. The main two modes are correlated with sea surface temperature (SST) anomalies in the tropical Pacific and Atlantic oceans. The teleconnections associated with global SST are then used to build a seasonal forecast model for PDSI over Amazonia based on predictors obtained from a sparse canonical correlation analysis approach. A unique feature of the presented drought prediction method is using only a few number of predictors to avoid excessive noise in the predictor space. Cross-validated results show correlations between observed and predicted spatial average PDSI up to 0.60 and 0.45 for lead times of 5 and 9 months, respectively. To the best of our knowledge, this is the first study in the region that, based on cross-validation results, leads to appreciable forecast skills for lead times beyond 4 months. This is a step forward in better understanding the dynamics of Amazonia droughts and improving risk assessment and management, through improved drought forecasting.

  12. Neogene Amazonia: Introduction to the special issue Journal of South American Earth Sciences, New contributions on Neogene geography and depositional environments in Amazonia

    NARCIS (Netherlands)

    Hoorn, C.; Vonhof, H.B.

    2006-01-01

    The paleontological data presented in this special issue provide a new insight into species migration and radiation in Amazonia during the Miocene. At the time, Amazonia was characterized by a very extensive, long-lived, semi-isolated, freshwater wetland ecosystem that was supplied with water and

  13. [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.

  14. 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...

  15. A mutation in the dam gene of Vibrio cholerae: 2-aminopurine sensitivity with intact GATC methylase activity

    International Nuclear Information System (INIS)

    Bandyopadhyay, R.; Sengupta, A.; Das, J.

    1989-01-01

    Vibrio cholerae mutants sensitive to 2-aminopurine (2AP) but with DNA adenine methylase activity similar to parental cells have been isolated. The mutant strains were sensitive to ultraviolet light (UV), methyl methanesulfonate (MMS) and 9-aminoacridine. The spontaneous mutation frequency of the mutants were not significantly affected. Attempts to isolate dam V. cholerae cells by screening 2AP sensitive cells have not been successful. All the mutant phenotypes could be suppressed by introducing the plasmid pRB103 carrying the dam gene of Escherichia coli into the mutant cells

  16. 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 ...

  17. Combating cholera epidemics by targeting reservoirs of infection ...

    African Journals Online (AJOL)

    Objectives: To determine the parameters which can be investigated for prevention and effective control of cholera. Data sources: Literature search on compact disk-read only memory (CD-ROM), medline and internet, using the key words: cholera outbreaks, and cholera transmission. A few reviews were manually reviewed.

  18. Cholera in Pregnancy: Outcomes from a Specialized Cholera Treatment Unit for Pregnant Women in L?og?ne, Haiti

    OpenAIRE

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

    2013-01-01

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

  19. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands

    OpenAIRE

    Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

    2016-01-01

    Background In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1?15 years in selected communities in Choiseul and Western Provinces. Methodology and Principal Findings We conducted a post-vaccination campaign, household-level survey about knowledg...

  20. 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.

    Directory of Open Access Journals (Sweden)

    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.

  1. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands.

    Science.gov (United States)

    Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

    2016-08-01

    In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1-15 years in selected communities in Choiseul and Western Provinces. We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04), to know signs and symptoms (64% vs. 22%; p = 0.02) and treatment (96% vs. 50%; p = 0.02) of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02). There were no differences in water, sanitation, and hygiene practices. This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH). Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities.

  2. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands.

    Directory of Open Access Journals (Sweden)

    Eleanor Burnett

    2016-08-01

    Full Text Available In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1-15 years in selected communities in Choiseul and Western Provinces.We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04, to know signs and symptoms (64% vs. 22%; p = 0.02 and treatment (96% vs. 50%; p = 0.02 of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02. There were no differences in water, sanitation, and hygiene practices.This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH. Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities.

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

    Science.gov (United States)

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

    2016-12-07

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

  4. Greenhouse gases study in Amazonia; Estudo de gases de efeito estufa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    D' Amelio, Monica Tais Siqueira

    2006-07-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO{sub 2} sources. The Amazon forest is a significant source of N{sub 2}O by soil process, and CH{sub 4} by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO{sub 2}, CH{sub 4}, CO, H{sub 2}, N{sub 2}O and SF{sub 6} have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO{sub 2} flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO{sub 2} flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H{sub 2} gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO{sub 2} sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that

  5. Greenhouse gases study in Amazonia; Estudo de gases de efeito estufa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    D' Amelio, Monica Tais Siqueira

    2006-07-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO{sub 2} sources. The Amazon forest is a significant source of N{sub 2}O by soil process, and CH{sub 4} by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO{sub 2}, CH{sub 4}, CO, H{sub 2}, N{sub 2}O and SF{sub 6} have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO{sub 2} flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO{sub 2} flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H{sub 2} gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO{sub 2} sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that, in the 2004 and

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-01-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Rütten, Thomas

    2009-01-01

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

  10. Killing mediated spatial structure in V. Cholerae biofilms

    Science.gov (United States)

    Yanni, David

    Most bacteria live in biofilms, which are implicated in 60 - 80 % of microbial infections in the body. The spatial structure of a biofilm confers advantages to its member-cells, such as antibiotic resistance, and is strongly affected by competition between strains and taxa. However, A complete picture of how competition affects the self-organized structure of these complex, far-from-equilibrium systems, is yet to emerge. To that end, we investigate phase separation dynamics driven by T6SS-facilitated bacterial warfare in a system composed of two strains of mutually antagonistic V. cholerae. T6SS is a contact mediated killing mechanism present in 25 % of all gram negative bacteria, and has been shown by recent work to play a major role in the spatial assortment of biofilms. T6SS events induce lysis, causing variations in local mechanical pressure, and acting as thermalizing events. We study cells immobilized in biofilms at the air-solid interface, so our experimental system represents a different type active matter, wherein activity is due to cell death and reproduction, not mobility. Here, we show how that activity imposes a constraint of minimal curvature on strain-strain interfaces; an effective Laplace pressure is characterized which governs interfacial dynamics.

  11. The Vibrio cholerae Extracellular Chitinase ChiA2 Is Important for Survival and Pathogenesis in the Host Intestine

    Science.gov (United States)

    Mondal, Moumita; Nag, Dhrubajyoti; Koley, Hemanta; Saha, Dhira Rani; Chatterjee, Nabendu Sekhar

    2014-01-01

    In aquatic environments, Vibrio cholerae colonizes mainly on the chitinous surface of copepods and utilizes chitin as the sole carbon and nitrogen source. Of the two extracellular chitinases essential for chitin utilization, the expression of chiA2 is maximally up-regulated in host intestine. Recent studies indicate that several bacterial chitinases may be involved in host pathogenesis. However, the role of V. cholerae chitinases in host infection is not yet known. In this study, we provide evidence to show that ChiA2 is important for V. cholerae survival in intestine as well as in pathogenesis. We demonstrate that ChiA2 de-glycosylates mucin and releases reducing sugars like GlcNAc and its oligomers. Deglycosylation of mucin corroborated with reduced uptake of alcian blue stain by ChiA2 treated mucin. Next, we show that V. cholerae could utilize mucin as a nutrient source. In comparison to the wild type strain, ΔchiA2 mutant was 60-fold less efficient in growth in mucin supplemented minimal media and was also ∼6-fold less competent to survive when grown in the presence of mucin-secreting human intestinal HT29 epithelial cells. Similar results were also obtained when the strains were infected in mice intestine. Infection with the ΔchiA2 mutant caused ∼50-fold less fluid accumulation in infant mice as well as in rabbit ileal loop compared to the wild type strain. To see if the difference in survival of the ΔchiA2 mutant and wild type V. cholerae was due to reduced adhesion of the mutant, we monitored binding of the strains on HT29 cells. The initial binding of the wild type and mutant strain was similar. Collectively these data suggest that ChiA2 secreted by V. cholerae in the intestine hydrolyzed intestinal mucin to release GlcNAc, and the released sugar is successfully utilized by V. cholerae for growth and survival in the host intestine. PMID:25244128

  12. Characterization of the Vibrio cholerae extracellular matrix: a top-down solid-state NMR approach.

    Science.gov (United States)

    Reichhardt, Courtney; Fong, Jiunn C N; Yildiz, Fitnat; Cegelski, Lynette

    2015-01-01

    Bacterial biofilms are communities of bacterial cells surrounded by a self-secreted extracellular matrix. Biofilm formation by Vibrio cholerae, the human pathogen responsible for cholera, contributes to its environmental survival and infectivity. Important genetic and molecular requirements have been identified for V. cholerae biofilm formation, yet a compositional accounting of these parts in the intact biofilm or extracellular matrix has not been described. As insoluble and non-crystalline assemblies, determinations of biofilm composition pose a challenge to conventional biochemical and biophysical analyses. The V. cholerae extracellular matrix composition is particularly complex with several proteins, complex polysaccharides, and other biomolecules having been identified as matrix parts. We developed a new top-down solid-state NMR approach to spectroscopically assign and quantify the carbon pools of the intact V. cholerae extracellular matrix using ¹³C CPMAS and ¹³C{(¹⁵N}, ¹⁵N{³¹P}, and ¹³C{³¹P}REDOR. General sugar, lipid, and amino acid pools were first profiled and then further annotated and quantified as specific carbon types, including carbonyls, amides, glycyl carbons, and anomerics. In addition, ¹⁵N profiling revealed a large amine pool relative to amide contributions, reflecting the prevalence of molecular modifications with free amine groups. Our top-down approach could be implemented immediately to examine the extracellular matrix from mutant strains that might alter polysaccharide production or lipid release beyond the cell surface; or to monitor changes that may accompany environmental variations and stressors such as altered nutrient composition, oxidative stress or antibiotics. More generally, our analysis has demonstrated that solid-state NMR is a valuable tool to characterize complex biofilm systems. Copyright © 2014. Published by Elsevier B.V.

  13. Cholera epidemic among Rwandan refugees: experience of ICDDR,B in Goma, Zaire.

    Science.gov (United States)

    Siddique, A K

    1994-01-01

    In July 1994, one of the worst cholera epidemics broke out among the nearly a million Rwandan refugees in Goma, eastern Zaire. The United Nations High Commission for Refugees estimated that nearly 12,000 people died during the epidemic. The International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) sent an eight-member medical team to Goma headed by Dr AK Siddique, a senior scientist of the Center and head of the Epidemic Control Preparedness Program, Dacca, Bangladesh. During their two-week stay, the team, in collaboration with UNICEF and the Ministry of Health, Zaire, conducted epidemiological assessment, operated a temporary treatment center and provided technical advice on case management of cholera and shigellosis to other health workers. The team also set up a microbiology laboratory in Goma to identify the pathogens responsible for the epidemic and their drug sensitivity patterns. The team visited a number of temporary treatment facilities in two of the five camp sites and provided technical advice to the health-care providers. They also visited treatment facilities in Goma city, where an estimated 200,000 refugees were affected by the epidemic. Deaths from cholera even in the treatment centers were much higher than expected. The overall case-fatality rate in the treatment centers was nearly 15%. Laboratory investigations showed that the initial epidemic was indeed caused by Vibrio cholerae strains resistant to tetracycline and doxycycline. By the first week of August, the number of cholera cases was declining, but the number of dysentery cases was increasing rapidly. Predominantly Shigella dysenteriae type 1 was responsible, which was resistant to most drugs used for treating shigellosis, except mecillinam. Inappropriate rehydration therapy and inadequate experience of health workers failed to prevent deaths. The team took over the operation of temporary treatment center at Katindo in Goma city with one of the highest case-fatality rates (14

  14. Cholera in pregnancy: Clinical and immunological aspects.

    Science.gov (United States)

    Khan, Ashraful I; Chowdhury, Fahima; Leung, Daniel T; Larocque, Regina C; Harris, Jason B; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi

    2015-10-01

    The objective of this study was to examine the clinical and immunological features of cholera in pregnancy. Women of reproductive age presenting to the icddr,b Dhaka hospital with cholera, and enrolled as part of a larger cohort study, were tested for pregnancy on admission. We compared initial clinical features and immune responses of pregnant patients with non-pregnant female patients at days 2, 7 and 21 after infection. Among reproductive age women enrolled between January 2001 and May 2006, 9.7% (14/144) were pregnant. The duration of diarrhoea prior to admission tended to be higher in pregnant compared to non-pregnant patients (p=0.08), but other clinical characteristics did not differ. Antibody responses to cholera toxin B subunit (CtxB), toxin-coregulated pilus A (TcpA), Vibrio cholerae lipopolysaccharide (LPS), and serum vibriocidal antibody responses, were comparable between pregnant and non-pregnant patients. There were no deaths among the pregnant cases or non-pregnant controls, and no adverse foetal outcomes, including stillbirths, during 21 days of follow up of pregnant cases. To our knowledge, this is the first report of immune responses in pregnant women with cholera. We found that pregnant woman early in pregnancy has comparable clinical illness and subsequent immune responses compared to non-pregnant women. These findings suggest that the evaluation of safety and immunogenicity of oral cholera vaccines in pregnancy should be an area of future investigations. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Efficiency of hospital cholera treatment in Ecuador

    Directory of Open Access Journals (Sweden)

    Creamer Germán

    1999-01-01

    Full Text Available This study analyzed the efficiency of cholera treatment in three hospitals representative of the Ecuadorian public health system in order to provide hospital directors and administrators and health service policy-makers with information to plan responses to future epidemics and to reduce the costs of cholera treatment in general. For the study, total and excess cholera treatment costs were calculated using hospital files and statistics and an in-hospital surveillance system of the cholera cases. The type and quantity of each input used for each treatment were analyzed, as well as the number of days hospitalized, according to the severity of the illness. With this process, excess costs were determined in relation to a "treatment norm" that would have been appropriate for each patient. The researchers found that 45% of the cholera treatment costs were excessive. The most important contributor was excess recurrent costs (90%, including extended hospital stays, disproportionate use of intravenous rehydration solutions, and unnecessary laboratory tests. Excess capital costs, from land, buildings, and hospital equipment, represented 10% of the total excess treatment costs. No significant relationship was found between treatment costs and the severity of the illness, nor between costs and a patient's age. A patient's sex appeared to be an important variable, with the cost of treating women being notably higher than for men. An inverse relationship was found between treatment costs and the complexity of the hospital. The researchers concluded there was an inefficient use of resources in the treatment of cholera in the three hospitals where the research was performed.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Stefan ePukatzki

    2013-12-01

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

  18. Novel type of specialized transduction for CTX phi or its satellite phage RS1 mediated by filamentous phage VGJ phi in Vibrio cholerae.

    Science.gov (United States)

    Campos, Javier; Martínez, Eriel; Marrero, Karen; Silva, Yussuan; Rodríguez, Boris L; Suzarte, Edith; Ledón, Talena; Fando, Rafael

    2003-12-01

    The main virulence factor of Vibrio cholerae, the cholera toxin, is encoded by the ctxAB operon, which is contained in the genome of the lysogenic filamentous phage CTX phi. This phage transmits ctxAB genes between V. cholerae bacterial populations that express toxin-coregulated pilus (TCP), the CTX phi receptor. In investigating new forms of ctxAB transmission, we found that V. cholerae filamentous phage VGJ phi, which uses the mannose-sensitive hemagglutinin (MSHA) pilus as a receptor, transmits CTX phi or its satellite phage RS1 by an efficient and highly specific TCP-independent mechanism. This is a novel type of specialized transduction consisting in the site-specific cointegration of VGJ phi and CTX phi (or RS1) replicative forms to produce a single hybrid molecule, which generates a single-stranded DNA hybrid genome that is packaged into hybrid viral particles designated HybP phi (for the VGJ phi/CTX phi hybrid) and HybRS phi (for the VGJ phi/RS1 hybrid). The hybrid phages replicate by using the VGJ phi replicating functions and use the VGJ phi capsid, retaining the ability to infect via MSHA. The hybrid phages infect most tested strains more efficiently than CTX phi, even under in vitro optimal conditions for TCP expression. Infection and lysogenization with HybP phi revert the V. cholerae live attenuated vaccine strain 1333 to virulence. Our results reinforce that TCP is not indispensable for the acquisition of CTX phi. Thus, we discuss an alternative to the current accepted evolutionary model for the emergence of new toxigenic strains of V. cholerae and the importance of our findings for the development of an environmentally safer live attenuated cholera vaccine.

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

    Science.gov (United States)

    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.

  20. 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

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

    Science.gov (United States)

    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.

  2. Incidence of Vibrio cholerae and related vibrios in a coastal lagoon and seawater influenced by lake discharges along an annual cycle.

    Science.gov (United States)

    Garay, E; Arnau, A; Amaro, C

    1985-08-01

    Most probable numbers of Vibrio cholerae and related vibrios were determined in Albufera Lake, Valencia, Spain, and in coastal waters under the influence of the lake discharges over the course of an annual cycle. The influence of temperature, kind of water, and characteristics of the different sampling sites on the numbers of vibrios recovered was evaluated. Maximum recovery of vibrios reached 10(3)/ml in both types of waters analyzed. V. cholerae numbers reached 10(3)/ml in the lake and 10(2) in one of the coastal sites. Frequently during the warm season, all vibrios isolated were identified as V. cholerae. Occasionally, no V. cholerae was recovered. The recovery of vibrios was significantly influenced by the temperature of the water and the type of water analyzed. Most of the V. cholerae isolates were included in Heiberg groups I and II, and nearly 50% of the strains used chitin as sole carbon source. Indole was not produced by 100% of the strains. All strains tested were non-O1 serovars.

  3. UNA NUEVA ESPECIE DE COSTUS (COSTACEAE DE LA AMAZONIA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    SALINAS NELSON

    2007-12-01

    Full Text Available Se describe e ilustra Costus fissicalyx N. R. Salinas, Clavijo & Betancur, una especienueva del sudeste de la Amazonia colombiana; además, se presenta información sobresus relaciones taxonómicas, distribución y hábitat. Costus fissicalyx se diferencia delas otras especies del género principalmente por la forma y el tipo de crecimientodel cáliz

  4. [The immunology of cholera and the molecular biology of cholera toxin. Recent progress and future perspectives].

    Science.gov (United States)

    Carrada-Bravo, T

    1994-01-01

    Vibrio cholerae has recently called the attention of researchers due to its strong immunogenicity and also because it serves as coadjunct immunomodulator of the immune response of the intestinal mucosae for the mixed added antigens as well as for those covalently linked to the toxin. The immunopathogeny of cholera is a complex phenomenon. This article presents the preliminary results of experiments conducted with laboratory rats in order to find the IgA intestinal response of rodents and humans.

  5. Age of depositional and weathering events in Central Amazonia

    Science.gov (United States)

    Sant'Anna, Lucy Gomes; Soares, Emílio Alberto do Amaral; Riccomini, Claudio; Tatumi, Sonia Hatsue; Yee, Marcio

    2017-08-01

    In the last three decades, several studies have been devoted to understanding the role of Late Pleistocene-Holocene climate changes in the Amazonia lowlands environment. However, most of these studies used data obtained from sedimentary deposits (lakes, swamps, and colluvium) located away from the central plain or on the edges of the Amazonia region. This article integrates optically stimulated luminescence and accelerated mass spectrometry 14C ages with sedimentological and geomorphological data obtained during this study or compiled from the literature for fluvial and lacustrine deposits of the central alluvial plain of the Solimões-Amazon River. The age data allow us to present a chronological framework for the Late Pleistocene-Holocene deposits and conclude that (i) the dryness of the LGM in central Amazonia lowlands is recorded by the formation of fluvial terraces and their weathering to pedogenic hematite between 25.3 ka and 17.7 ka; (ii) floodplain deposition was contemporaneous with terrace weathering and occurred in a context of decreased water volume in fluvial channels, lowering of river base level and sea level, and isostatic rebound of the continent; and (iii) lateral and mid-channel fluvial bars in the Solimões-Amazon River have a minimum age of 11.5 ± 1.5 ka, and their deposition responded to increased precipitation at the beginning of the Holocene.

  6. Las palmeras en los valles principales de la Amazonia peruana

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available LES PALMIERS DES PRINCIPALES VALLEES DE L’AMAZONIE PERUVIENNE. La distribution géographique des espèces de palmiers de l’Amazonie péruvienne est présentée selon les principales vallées. Pour chaque affluent important est donnée la liste des espèces récoltées, et pour chaque espèce sont réunies les références des échantillons d’herbiers, collecteur(s et numéro de collection, ainsi que les herbiers de dépôt. Se presenta la distribución de las palmeras de la Amazonia en función de los valles principales. Por cada río de mayor importancia, se da la lista de las especies colectadas, las referencias de las muestras botánicas, colector(es y número de colección, y los herbarios de depósito de dichas muestras. PALMS OF THE MAJOR RIVER VALLEYS OF PERUVIAN AMAZONIA. Palm species distribution in Peruvian Amazonia is presented according to the major river valleys. The species collected are listed for each tributary valley. The collection references, collector(s and number of the specimen and the herbaria of deposit are given for each species.

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    . Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...... with respect to host background in three different Escherichia coli strains, i.e. an isogenic set of K-12 strains, differing in the presence of an indigenous fim gene cluster, as well as a wild-type isolate. Immunization of rabbits with purified chimeric fimbriae resulted in serum which specifically recognized...

  8. Pasteurella multocida from outbreaks of avian cholera in wild and captive birds in Denmark

    DEFF Research Database (Denmark)

    Pedersen, Karl; Dietz, Hans-Henrik; Jørgensen, J.C.

    2003-01-01

    An outbreak of avian cholera was observed among wild birds in a few localities in Denmark in 2001. The highest mortalities were among breeding ciders (Somateria mollissima) and gulls (Larus spp.). Pulsed-field gel electrophoresis (PFGE) was conducted using ApaI and SmaI as restriction enzymes...... the outbreak strain. Among 68 isolates from wild birds, only one PFGE and one REA pattern were demonstrated, whereas among 23 isolates from domestic poultry, 14 different SmaI, 12 different ApaI, and 10 different HpaII patterns were found. The results suggest that a P. multocida strain has survived during...

  9. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. I. Dactyloidae, Hoplocercidae, Iguanidae, Leiosauridae, Polychrotidae, Tropiduridae.

    Science.gov (United States)

    Ribeiro-Júnior, Marco A

    2015-07-08

    I present distribution data of all Dactyloidae, Hoplocercidae, Iguanidae, Leiosauridae, Polychrotidae and Tropiduridae lizards known from the Brazilian Amazonia, totaling 40 species-level taxa, belonging to 11 genera. This represents four more species-level taxa than previously reported for these families. Data were based on the direct examination of 41,243 specimens deposited in three North American and eight Brazilian musea, including the main collections harboring Amazonian material. Most species (62.5%) are endemic to the Amazonia; non-endemic species are mainly associated with open dry (semideciduous) forest or open vegetation (savanna) enclaves in Amazonia, with a few exceptions. As a whole, seven taxa are widespread in Amazonia, one is restricted to eastern Amazonia, three to western Amazonia, five to northern Amazonia (either in part of it or widespread in the Guiana region), two to northwestern Amazonia, one to southern Amazonia, nine to southwestern Amazonia, and seven to the southern peripheral portion of Amazonia. Five species have unique distributions and five species have a distribution that is congruent with one of the areas of endemism (AE) recognized for other organisms (birds and primates). The first herpetological gazetteer for the Brazilian Amazonia with about 3,600 georeferenced localities was also produced.

  10. Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP-cAMP Receptor Protein Signaling System.

    Directory of Open Access Journals (Sweden)

    M Shamim Hasan Zahid

    Full Text Available Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT and toxin coregulated pilus (TCP, the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP-cAMP receptor protein (CRP is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.

  11. Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System.

    Science.gov (United States)

    Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Asakura, Masahiro; Chatterjee, Shruti; Hinenoya, Atsushi; Faruque, Shah M; Yamasaki, Shinji

    2015-01-01

    Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT) and toxin coregulated pilus (TCP), the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP)-cAMP receptor protein (CRP) is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.

  12. [A prognostic model of a cholera epidemic].

    Science.gov (United States)

    Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

    1994-01-01

    A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

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

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

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

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

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

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

  15. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Malawi Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE ...

  16. 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.

  17. New Odostomia species (Gastropoda, Heterobranchia, Pyramidellidae) from the Miocene Pebas Formation of Western Amazonia (Peru, Colombia)

    NARCIS (Netherlands)

    Aartsen, van J.J.; Wesselingh, F.P.

    2000-01-01

    Odostomia nuttalli spec. nov. and O. coluhensis spec. nov. are described from the Miocene Pebas Formation of Peruvian and Columbian Amazonia. A third pyramidellid snail is also diagnosed. These species are indicators for marine influence in the late Middle to early Late Miocence of Western Amazonia.

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

    Directory of Open Access Journals (Sweden)

    Salvador Almagro-Moreno

    2015-04-01

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

  19. Fuzzy expert systems and GIS for cholera health risk prediction in southern Africa

    CSIR Research Space (South Africa)

    Fleming, GJ

    2007-01-01

    Full Text Available Cholera (Vibrio cholerae) is endemic in southern Africa and frequently breaks out in epidemics along the eastern seaboard. Extensive resources are directed at combating cholera yet it remains a significant problem. Limited resources could better...

  20. SURVEY ON V. CHOLERAE, V. VULNIFICUS AND V. PARAHAEMOLYTICUS IN BIVALVE MOLLUSCS OF THE ADRIATIC SEA AND PROPOSAL OF AN ANALYTICAL PROTOCOL

    Directory of Open Access Journals (Sweden)

    M.L. Valeri

    2009-06-01

    Full Text Available Bivalve molluscs from Adriatic sea were analyzed for V. parahaemolyticus, V. cholerae e V. vulnificus presence. The isolates on TCBS Agar and m-CPC Agar were selected on the basis of a new biochemical screening, that showed a good performance, because among 2344 strains from primary culture only 237 (10% were presumptively assigned to the species of interest. The PCR analyses was performed for the target genes toxR hlyA, ctxA, tcpI (V. cholerae, toxR, tl, tdh, trh (V. parahaemolyticus, vvhA and viuB (V. vulnificus. Among the 9 strains confirmed to belong to V. parahaemolyticus specie, 6 were sucrose positive. On 215 samples of molluscs only 5 resulted positive for V. parahaemolyticus being toxR+, tl+, although non pathogenic (tdh-, trh-, and none for V. cholerae e V. vulnificus.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  4. 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

  5. Use of a real time PCR assay for detection of the ctxA gene of Vibrio cholerae in an environmental survey of Mobile Bay.

    Science.gov (United States)

    Blackstone, George M; Nordstrom, Jessica L; Bowen, Michael D; Meyer, Richard F; Imbro, Paula; DePaola, Angelo

    2007-02-01

    Toxigenic Vibrio cholerae, the etiological agent of cholera, is a natural inhabitant of the marine environment and causes severe diarrheal disease affecting thousands of people each year in developing countries. It is the subject of extensive testing of shrimp produced and exported from these countries. We report the development of a real time PCR (qPCR) assay to detect the gene encoding cholera toxin, ctxA, found in toxigenic V. cholerae strains. This assay was tested against DNA isolated from soil samples collected from diverse locations in the US, a panel of eukaryotic DNA from various sources, and prokaryotic DNA from closely related and unrelated bacterial sources. Only Vibrio strains known to contain ctxA generated a fluorescent signal with the 5' nuclease probe targeting the ctxA gene, thus confirming the specificity of the assay. In addition, the assay was quantitative in pure culture across a six-log dynamic range down to <10 CFU per reaction. To test the robustness of this assay, oysters, aquatic sediments, and seawaters from Mobile Bay, AL, were analyzed by qPCR and traditional culture methods. The assay was applied to overnight alkaline peptone water enrichments of these matrices after boiling the enrichments for 10 min. Toxigenic V. cholerae strains were not detected by either qPCR or conventional methods in the 16 environmental samples examined. A novel exogenous internal amplification control developed by us to prevent false negatives identified the samples that were inhibitory to the PCR. This assay, with the incorporated internal control, provides a highly specific, sensitive, and rapid detection method for the detection of toxigenic strains of V. cholerae.

  6. The molecular epidemiology of cholera in Latin America.

    Science.gov (United States)

    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.

  7. Updated Global Burden of Cholera in Endemic Countries

    Science.gov (United States)

    Ali, Mohammad; Nelson, Allyson R.; Lopez, Anna Lena; Sack, David A.

    2015-01-01

    Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control. PMID:26043000

  8. The Orphans of Cholera Morbus in Yucatan, 1833

    OpenAIRE

    Elsa Malvido; Paola Peniche Moreno

    2013-01-01

    This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socia...

  9. Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

    Directory of Open Access Journals (Sweden)

    S. González Fraga

    2009-03-01

    its virulence factors by PCR, antimicrobial susceptibility patterns and genetic diversity by pulsed-field gel electrophoresis. Eight virulence patterns were obtained although no isolate was positive for the cholera toxin or the thermostable toxin. Four isolates were positive for the type three secretion system. The 17.6% of the isolates were resistant or intermediate to ampicillin and 5.9% were resistant to trimethoprim-sulfamethoxazole. By SfiI-PFGE, all isolates were genetically very diverse, as 27 different patterns were identified in 29 typeable isolates by pulsed-field gel electrophoresis. Although it has a low incidence, V. cholerae continues to be a causative agent of diarrhea in children, who are affected by a variety of circulating strains of V. cholerae non-O1, non-O139.

  10. Human Gut Microbiota Predicts Susceptibility to Vibrio cholerae Infection.

    Science.gov (United States)

    Midani, Firas S; Weil, Ana A; Chowdhury, Fahima; Begum, Yasmin A; Khan, Ashraful I; Debela, Meti D; Durand, Heather K; Reese, Aspen T; Nimmagadda, Sai N; Silverman, Justin D; Ellis, Crystal N; Ryan, Edward T; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; David, Lawrence A; LaRocque, Regina C

    2018-04-12

    Cholera is a public health problem worldwide and the risk factors for infection are only partially understood. We prospectively studied household contacts of cholera patients to compare those who were infected with those who were not. We constructed predictive machine learning models of susceptibility using baseline gut microbiota data. We identified bacterial taxa associated with susceptibility to Vibrio cholerae infection and tested these taxa for interactions with V. cholerae in vitro. We found that machine learning models based on gut microbiota predicted V. cholerae infection as well as models based on known clinical and epidemiological risk factors. A 'predictive gut microbiota' of roughly 100 bacterial taxa discriminated between contacts who developed infection and those who did not. Susceptibility to cholera was associated with depleted levels of microbes from the phylum Bacteroidetes. By contrast, a microbe associated with cholera by our modeling framework, Paracoccus aminovorans, promoted the in vitro growth of V. cholerae. Gut microbiota structure, clinical outcome, and age were also linked. These findings support the hypothesis that abnormal gut microbial communities are a host factor related to V. cholerae susceptibility.

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

    Directory of Open Access Journals (Sweden)

    Md Abu Sayeed

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

  12. 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...

  13. Eficiencia reproductiva de diferentes genotipos bovinos en la Amazonia Ecuatoriana

    OpenAIRE

    Ortiz Naveda, N. R.; Castro Guamán, W. E.; Marin, P. R.; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca; DIUC

    2015-01-01

    Los problemas reproductivos en el centro de la Amazonia Ecuatoriana, están condicionados por un sin número de factores, que directa e indirectamente conspiran para mejorar los parámetros productivos de la zona. Las condiciones ambientales, el manejo, la falta de energía en la dieta, la salud, la infraestructura y los genotipos utilizados influyen para no lograr una eficiente reproducción Lopez et al., 2014). El anestro posparto es el principal factor que afecta negativamente el desempeño repr...

  14. Ozone concentrations in the Brazilian Amazonia during BASE-A

    International Nuclear Information System (INIS)

    Setzer, A.W.; Kirchhoff, V.W.J.H.; Pereira, M.C.

    1991-01-01

    During the Biomass Burning Airborne and Spaceborne Experiment--Amazonia, thermal images of fires were made with the Advanced Very High Resolution Radiometer (AVHRR) on board meteorological NOAA series satellites. The results of ozone measurements made on board the Brazilian Institute for Space Research (INPE) airplane during September of 1989 are presented and analyzed in relation to the temporal and geographical location of fires detected before and during the sampling. Results show that on a synoptic scale, concentrations of ozone rise sharply in regions of more intense burning

  15. Outbreaks of cholera-like diarrhoea caused by enterotoxigenic Escherichia coli in the Brazilian Amazon Rainforest.

    Science.gov (United States)

    Vicente, Ana C P; Teixeira, Luiz F M; Iniguez-Rojas, L; Luna, M G; Silva, L; Andrade, J R C; Guth, B E C

    2005-09-01

    The relationship between enteropathogens and severe diarrhoea in the Brazilian Amazon is poorly understood. In 1998, outbreaks of acute diarrhoea clinically diagnosed as cholera occurred in two small villages localized far from the main cholera route in the Brazilian rainforest. PCR was performed on some enteropathogens and heat-labile (LT) and/or heat-stable (STh) toxin genes, the virulence determinants of enterotoxigenic Escherichia coli (ETEC), were detected. Further characterization of ETEC isolates revealed the presence of two clones, one from each outbreak. One presenting serotype O167:H5 harboured LT-I and STh toxin genes and expressed the CS5CS6 colonization factor. The other, a non-typeable serotype, was positive for the LT-I gene and expressed the CS7 colonization factor. The current study demonstrates the importance of molecular diagnosis in regions such as the Amazon basin, where the enormous distances and local support conditions make standard laboratory diagnosis difficult. Here we also show that the mis-identified cholera cases were in fact associated with ETEC strains. This is the first report of ETEC, molecularly characterized as the aetiological agent of severe diarrhoea in children and adults in the Brazilian Amazon Rainforest.

  16. Mapping to Support Fine Scale Epidemiological Cholera Investigations: A Case Study of Spatial Video in Haiti

    Directory of Open Access Journals (Sweden)

    Andrew Curtis

    2016-02-01

    Full Text Available The cartographic challenge in many developing world environments suffering a high disease burden is a lack of granular environmental covariates suitable for modeling disease outcomes. As a result, epidemiological questions, such as how disease diffuses at intra urban scales are extremely difficult to answer. This paper presents a novel geospatial methodology, spatial video, which can be used to collect and map environmental covariates, while also supporting field epidemiology. An example of epidemic cholera in a coastal town of Haiti is used to illustrate the potential of this new method. Water risks from a 2012 spatial video collection are used to guide a 2014 survey, which concurrently included the collection of water samples, two of which resulted in positive lab results “of interest” (bacteriophage specific for clinical cholera strains to the current cholera situation. By overlaying sample sites on 2012 water risk maps, a further fifteen proposed water sample locations are suggested. These resulted in a third spatial video survey and an additional “of interest” positive water sample. A potential spatial connection between the “of interest” water samples is suggested. The paper concludes with how spatial video can be an integral part of future fine-scale epidemiological investigations for different pathogens.

  17. Using mobile phone data to predict the spatial spread of cholera.

    Science.gov (United States)

    Bengtsson, Linus; Gaudart, Jean; Lu, Xin; Moore, Sandra; Wetter, Erik; Sallah, Kankoe; Rebaudet, Stanislas; Piarroux, Renaud

    2015-03-09

    Effective response to infectious disease epidemics requires focused control measures in areas predicted to be at high risk of new outbreaks. We aimed to test whether mobile operator data could predict the early spatial evolution of the 2010 Haiti cholera epidemic. Daily case data were analysed for 78 study areas from October 16 to December 16, 2010. Movements of 2.9 million anonymous mobile phone SIM cards were used to create a national mobility network. Two gravity models of population mobility were implemented for comparison. Both were optimized based on the complete retrospective epidemic data, available only after the end of the epidemic spread. Risk of an area experiencing an outbreak within seven days showed strong dose-response relationship with the mobile phone-based infectious pressure estimates. The mobile phone-based model performed better (AUC 0.79) than the retrospectively optimized gravity models (AUC 0.66 and 0.74, respectively). Infectious pressure at outbreak onset was significantly correlated with reported cholera cases during the first ten days of the epidemic (p Mobile operator data is a highly promising data source for improving preparedness and response efforts during cholera outbreaks. Findings may be particularly important for containment efforts of emerging infectious diseases, including high-mortality influenza strains.

  18. CHOLERA EL-TOR EN IRAN

    Directory of Open Access Journals (Sweden)

    M. Ghodssi

    1969-01-01

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

  19. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

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

    2013-12-01

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

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

    Science.gov (United States)

    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.

  1. Antibacterial activity of polyphenolic fraction of Kombucha against Vibrio cholerae: targeting cell membrane.

    Science.gov (United States)

    Bhattacharya, D; Ghosh, D; Bhattacharya, S; Sarkar, S; Karmakar, P; Koley, H; Gachhui, R

    2018-02-01

    The present study was undertaken to determine the mechanism of antibacterial activity of a polyphenolic fraction, composed of mainly catechin and isorhamnetin, previously isolated from Kombucha, a 14-day fermented beverage of sugared black tea, against the enteropathogen Vibrio cholerae N16961. Bacterial growth was found to be seriously impaired by the polyphenolic fraction in a dose-dependent manner. Scanning Electron Microscopy demonstrated morphological alterations in bacterial cells when exposed to the polyphenolic fraction in a concentration-dependent manner. Permeabilization assays confirmed that the fraction disrupted bacterial membrane integrity in both time- and dose-dependent manners, which were proportional to the production of intracellular reactive oxygen species (ROS). Furthermore, each of the polyphenols catechin and isorhamnetin showed the ability to permeate bacterial cell membranes by generating oxidative stress, thereby suggesting their role in the antibacterial potential of Kombucha. Thus, the basic mechanism of antibacterial activity of the Kombucha polyphenolic fraction against V. cholerae involved bacterial membrane permeabilization and morphological changes, which might be due to the generation of intracellular ROS. To the best of our knowledge, this is the first report on the investigation of antibacterial mechanism of Kombucha, which is mostly attributed to its polyphenolic content. The emergence of multidrug-resistant Vibrio cholerae strains has hindered an efficient anti-Vibrio therapy. This study has demonstrated the membrane damage-mediated antibacterial mechanism of Kombucha, a popular fermented beverage of sugared tea, which is mostly attributed to its polyphenolic content. This study also implies the exploitation of Kombucha as a potential new source of bioactive polyphenols against V. cholerae. © 2017 The Society for Applied Microbiology.

  2. Local population and regional environmental drivers of cholera in Bangladesh

    Directory of Open Access Journals (Sweden)

    Escamilla Veronica

    2010-01-01

    Full Text Available Abstract Background Regional environmental factors have been shown to be related to cholera. Previous work in Bangladesh found that temporal patterns of cholera are positively related to satellite-derived environmental variables including ocean chlorophyll concentration (OCC. Methods This paper investigates whether local socio-economic status (SES modifies the effect of regional environmental forces. The study area is Matlab, Bangladesh, an area of approximately 200,000 people with an active health and demographic surveillance system. Study data include (1 spatially-referenced demographic and socio-economic characteristics of the population; (2 satellite-derived variables for sea surface temperature (SST, sea surface height (SSH, and OCC; and (3 laboratory confirmed cholera case data for the entire population. Relationships between cholera, the environmental variables, and SES are measured using generalized estimating equations with a logit link function. Additionally two separate seasonal models are built because there are two annual cholera epidemics, one pre-monsoon, and one post-monsoon. Results SES has a significant impact on cholera occurrence: the higher the SES score, the lower the occurrence of cholera. There is a significant negative association between cholera incidence and SSH during the pre-monsoon period but not for the post-monsoon period. OCC is positively associated with cholera during the pre-monsoon period but not for the post-monsoon period. SST is not related to cholera incidence. Conclusions Overall, it appears cholera is influenced by regional environmental variables during the pre-monsoon period and by local-level variables (e.g., water and sanitation during the post-monsoon period. In both pre- and post-monsoon seasons, SES significantly influences these patterns, likely because it is a proxy for poor water quality and sanitation in poorer households.

  3. Plasticity of regulation of mannitol phosphotransferase system operon by CRP-cAMP complex in Vibrio cholerae.

    Science.gov (United States)

    Zhou, Yan Yan; Zhang, Hong Zhi; Liang, Wei Li; Zhang, Li Juan; Zhu, Jun; Kan, Biao

    2013-10-01

    The complex of the cyclic AMP receptor protein (CRP) and cAMP is an important transcriptional regulator of numerous genes in prokaryotes. The transport of mannitol through the phosphotransferase systems (PTS) is regulated by the CRP-cAMP complex. The aim of the study is to investigate how the CRP-cAMP complex acting on the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype. The crp mutant strain was generated by homologous recombination to assess the need of CRP to activate the mannitol PTS operon of V. cholerae El Tor. Electrophoretic mobility shift assays (EMSA) and the reporter plasmid pBBRlux were used to confirm the role that the CRP-cAMP complex playing on the mannitol PTS operon mtl. In this study, we confirmed that CRP is strictly needed for the activation of the mtl operon. We further experimentally identified five CRP binding sites within the promoter region upstream of the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype and found that these sites display different affinities for CRP and provide different contributions to the activation of the operon. The five binding sites collectively confer the strong activation of mannitol transfer by CRP in V. cholerae, indicating an elaborate and subtle CRP activation mechanism. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  4. Response of Vibrio cholerae to Low-Temperature Shifts: CspV Regulation of Type VI Secretion, Biofilm Formation, and Association with Zooplankton.

    Science.gov (United States)

    Townsley, Loni; Sison Mangus, Marilou P; Mehic, Sanjin; Yildiz, Fitnat H

    2016-07-15

    The ability to sense and adapt to temperature fluctuation is critical to the aquatic survival, transmission, and infectivity of Vibrio cholerae, the causative agent of the disease cholera. Little information is available on the physiological changes that occur when V. cholerae experiences temperature shifts. The genome-wide transcriptional profile of V. cholerae upon a shift in human body temperature (37°C) to lower temperatures, 15°C and 25°C, which mimic those found in the aquatic environment, was determined. Differentially expressed genes included those involved in the cold shock response, biofilm formation, type VI secretion, and virulence. Analysis of a mutant lacking the cold shock gene cspV, which was upregulated >50-fold upon a low-temperature shift, revealed that it regulates genes involved in biofilm formation and type VI secretion. CspV controls biofilm formation through modulation of the second messenger cyclic diguanylate and regulates type VI-mediated interspecies killing in a temperature-dependent manner. Furthermore, a strain lacking cspV had significant defects for attachment and type VI-mediated killing on the surface of the aquatic crustacean Daphnia magna Collectively, these studies reveal that cspV is a major regulator of the temperature downshift response and plays an important role in controlling cellular processes crucial to the infectious cycle of V. cholerae Little is known about how human pathogens respond and adapt to ever-changing parameters of natural habitats outside the human host and how environmental adaptation alters dissemination. Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, experiences fluctuations in temperature in its natural aquatic habitats and during the infection process. Furthermore, temperature is a critical environmental signal governing the occurrence of V. cholerae and cholera outbreaks. In this study, we showed that V. cholerae reprograms its transcriptome in response to

  5. 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

    2010-01-01

    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 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 (CTXCL) prophage, ctxBCL and rstRCL, in addition to resident rstRET, 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. PMID:20668130

  6. Secondary Forests from Agricultural Abandonment in Amazonia 2000-2009

    Science.gov (United States)

    Morton, Douglas

    2010-01-01

    Ongoing negotiations to include reducing emissions from tropical deforestation and forest degradation (REDD+) in a post-Kyoto climate agreement highlight the critical role of satellite data for accurate and transparent accounting of forest cover changes. In addition to deforestation and degradation, knowledge of secondary forest dynamics is essential for full carbon accounting under REDD+. Land abandonment to secondary forests also frames one of the key tradeoffs for agricultural production in tropical forest countries-whether to incentivize secondary forest growth (for carbon sequestration and biodiversity conservation) or low-carbon expansion of agriculture or biofuels production in areas of secondary forests. We examined patterns of land abandonment to secondary forest across the arc of deforestation in Brazil and Bolivia using time series of annual Landsat and MODIS data from 2000-2009. Rates of land abandonment to secondary forest during 2002-2006 were less than 5% of deforestation rates in these years. Small areas of new secondary forest were scattered across the entire arc of deforestation, rather than concentrated in any specific region of the basin. Taken together, our analysis of the satellite data record emphasizes the difficulties of addressing the pool of new secondary forests in the context of REDD+ in Amazonia. Due to the small total area of secondary forests, land sparing through agricultural intensification will be an important element of efforts to reduce deforestation rates under REDD+ while improving agricultural productivity in Amazonia.

  7. The expansion of intensive agriculture and ranching in Brazilian Amazonia

    Science.gov (United States)

    Walker, Robert; DeFries, Ruth; del Carmen Vera-Diaz, Maria; Shimabukuro, Yosio; Venturieri, Adriano

    Agriculture in Amazonia has often provoked controversy, given the tremendous ecological value of the region's environment. First with ranching, and now with the soybean boom, tractors and cattle have marched across lands that for millennia supported only closed moist forest, resident ecosystems, and dispersed indigenous peoples. The present chapter considers this expansion, focusing on the Brazilian portion of the basin. Its premise is that effective Amazonian policy must be grounded on an understanding of the region's agriculture. The chapter pursues its objectives by first addressing the development initiatives that created the preconditions for Amazonia's current agricultural economy. The region is remote and has therefore required sustained government intervention to release its potential. The policy discussion is followed by descriptions of cattle ranching and soy farming. For each, market settings and trajectories of expansion are presented. Although these sectoral descriptions are data rich, they do not provide a conceptual framework for analyzing the environmental impacts of evolving market conditions. To accomplish this, the chapter invokes the classical land use model of von Thünen to explain Amazonian land cover dynamics in relation to soy-cattle linkages. It addresses these dynamics with remote sensing data from Mato Grosso, Pará, and Rondônia, and then discusses scenarios of agricultural advances on the forest. Conclusions follow, considering possible policy responses to deforestation, and the social context of agricultural intensification, with special attention to the issues of land tenure security and distributional equity.

  8. 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

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

    1987-01-01

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

  12. Cholera outbreak in districts around Lake Chilwa, Malawi: Lessons ...

    African Journals Online (AJOL)

    Cholera is endemic in Malawi with seasonal outbreaks during the wet season. People living around Lake Chilwa rely on the lake for their water supply. From May 2009 to May 2010, a cholera outbreak occurred in fishing communities around Lake Chilwa. This paper describes the outbreak response and lessons learned for ...

  13. Dealing with cholera: exclusively the domain of environmental ...

    African Journals Online (AJOL)

    Cholera outbreaks have a profound impact on the health and well-being of communities. Especially young children are vulnerable to the disease and schools report high absenteeism during epidemics. There is both the perception and evidence thereof, that educating communities about cholera (its prevention and ...

  14. Cultural influences behind cholera transmission in the Far North ...

    African Journals Online (AJOL)

    Introduction: in recent years, the Far North Region of Cameroon has experienced serious and recurrent cholera outbreaks. Yet, understanding of cultural influences on outbreaks and spread remain poorly understood. This qualitative study explored cultural influences on cholera exposure in this region. Methods: interviews ...

  15. Risk factors associated with cholera in Harare City, Zimbabwe, 2008 ...

    African Journals Online (AJOL)

    Objective: Two suspected cholera cases at Beatrice Road Infectious Diseases Hospital were reported to Harare City Health on 14 October 2008 setting in motion investigation and control measures. We determined the extent of the epidemic and risk factors for contracting cholera. Methods: An unmatched 1:1 case-control ...

  16. Potential impact of reactive vaccination in controlling cholera ...

    African Journals Online (AJOL)

    Background. To contain ongoing cholera outbreaks, the World Health Organization has suggested that reactive vaccination should be considered in addition to its previous control measures. Objectives. To explore the potential impact of a hypothetical reactive oral cholera vaccination using the example of the recent ...

  17. The cholera epidemic in South Africa, 1980 - 1987 Epidemiological ...

    African Journals Online (AJOL)

    During the cholera epidemic in South Africa, 1980-1987, 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in most years. The vast ...

  18. Geographical patterns of cholera in Mexico, 1991-1996.

    Science.gov (United States)

    Borroto, R J; Martinez-Piedra, R

    2000-08-01

    The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera. Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level. Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04). This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance.

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

    African Journals Online (AJOL)

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

  20. Estimating effects of improved drinking water and sanitation on cholera.

    Science.gov (United States)

    Leidner, Andrew J; Adusumilli, Naveen C

    2013-12-01

    Demand for adequate provision of drinking-water and sanitation facilities to promote public health and economic growth is increasing in the rapidly urbanizing countries of the developing world. With a panel of data on Asia and Africa from 1990 to 2008, associations are estimated between the occurrence of cholera outbreaks, the case rates in given outbreaks, the mortality rates associated with cholera and two disease control mechanisms, drinking-water and sanitation services. A statistically significant and negative effect is found between drinking-water services and both cholera case rates as well as cholera-related mortality rates. A relatively weak statistical relationship is found between the occurrence of cholera outbreaks and sanitation services.

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

    Directory of Open Access Journals (Sweden)

    Murad Lesmana

    2012-09-01

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

  2. 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.

  3. The health economics of cholera: A systematic review.

    Science.gov (United States)

    Hsiao, Amber; Hall, Angela H; Mogasale, Vittal; Quentin, Wilm

    2018-06-12

    Vibrio cholera is a major contributor of diarrheal illness that causes significant morbidity and mortality globally. While there is literature on the health economics of diarrheal illnesses more generally, few studies have quantified the cost-of-illness and cost-effectiveness of cholera-specific prevention and control interventions. The present systematic review provides a comprehensive overview of the literature specific to cholera as it pertains to key health economic measures. A systematic review was performed with no date restrictions up through February 2017 in PubMed, Econlit, Embase, Web of Science, and Cochrane Review to identify relevant health economics of cholera literature. After removing duplicates, a total of 1993 studies were screened and coded independently by two reviewers, resulting in 22 relevant studies. Data on population, methods, and results (cost-of-illness and cost-effectiveness of vaccination) were compared by country/region. All costs were adjusted to 2017 USD for comparability. Costs per cholera case were found to be rather low: $1000/case. There is adequate evidence to support the economic value of vaccination for the prevention and control of cholera when vaccination is targeted at high-incidence populations and/or areas with high case fatality rates due to cholera. When herd immunity is considered, vaccination also becomes a cost-effective option for the general population and is comparable in cost-effectiveness to other routine immunizations. Cholera vaccination is a viable short-to-medium term option, especially as the upfront costs of building water, sanitation, and hygiene (WASH) infrastructure are considerably higher for countries that face a significant burden of cholera. While WASH may be the more cost-effective solution in the long-term when implemented properly, cholera vaccination can still be a feasible, cost-effective strategy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Killed oral cholera vaccines: history, development and implementation challenges.

    Science.gov (United States)

    Lopez, Anna Lena; Gonzales, Maria Liza Antoinette; Aldaba, Josephine G; Nair, G Balakrish

    2014-09-01

    Cholera is still a major global health problem, affecting mainly people living in unsanitary conditions and who are at risk for outbreaks of cholera. During the past decade, outbreaks are increasingly reported from more countries. From the early killed oral cholera vaccine, rapid improvements in vaccine development occurred as a result of a better understanding of the epidemiology of the disease, pathogenesis of cholera infection and immunity. The newer-generation oral killed cholera vaccines have been shown to be safe and effective in field trials conducted in cholera endemic areas. Likewise, they have been shown to be protective when used during outbreak settings. Aside from providing direct protection to vaccinated individuals, recent studies have demonstrated that these killed oral vaccines also confer indirect protection through herd immunity. Although new-generation oral cholera vaccines should not be considered in isolation from other preventive approaches in countries where they are most needed, especially improved water quality and sanitation, these vaccines serve as immediately available public health tools for preventing further morbidity and mortality from cholera. However, despite its availability for more than two decades, use of these vaccines has not been optimized. Although there are limitations of the currently available oral cholera vaccines, recent data show that the vaccines are safe, feasible to use even in difficult circumstances and able to provide protection in various settings. Clear identification of the areas and target population groups who will benefit from the use of the cholera vaccines will be required and strategies to facilitate accessibility and usage of these vaccines in these areas and population groups will need to be developed.

  5. Nuevas especies de Axonopus (Poaceae: Panicoideae: Paniceae de la Amazonia Colombiana

    Directory of Open Access Journals (Sweden)

    Giraldo Cañas Diego

    1998-11-01

    Full Text Available Two new species of Axonopus, A. morronei (series Axonopus and A. zuloagae (series Barbigen are described. The new species are known only from the savannas and sandstone plateau of Colombian northwest Amazonia.Se describen dos nuevas especies de Axonopus, A. morronei y A. zuloagae, de las series Axonopus y Barbigeri, respectivamente. Las nuevas especies son conocidas únicamente de las sabanas y afloramientos rocosos de la Amazonia noroccidental colombiana.

  6. 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

  7. 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.

  8. Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

    Science.gov (United States)

    Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

    2010-05-01

    The nature of waterborne diseases, among which cholera has a prominent importance, calls for a better understanding of the link between epidemic spreading, water and climate. To this end, we have developed a framework which involves a network-based description of a river system, connected with local communities which act as nodes of the network. This has allowed us to produce consistent simulations of real case studies. More recent investigations comprise the evaluation of the spreading velocity of an epidemic wave by means of a reaction-diffusion modeling approach. In particular, we have found that both transport processes and epidemiological quantities, such as the basic reproduction number, have a crucial effect in controlling the spreading of the epidemics. We first developed a description of bacterial movement along the network driven by advection and diffusion; afterward, we have included the movement of human populations. This latter model allowed us to establish the conditions that can trigger epidemic waves that start from the coastal region, where bacteria are autochthonous, and travel inland. In particular, our findings suggest that even relatively low values of human diffusion can have the epidemic propagate upstream. The interaction between climate, hydrology and epidemic events is still much debated, since no clear correlation between climatologic and epidemiological phenomena has emerged so far. However, a spatial assessment of hydrological and epidemiological mechanisms could be crucial to understand the evolution of cholera outbreaks. In particular, a hotly debated topic is the understanding of the mechanisms that can generate patterns of cholera incidence that exhibit an intra-annual double peak, as frequently observed in endemic region such as Bangladesh. One of the possible explanations proposed in the literature is that spring droughts cause bacteria concentration in water to rise dramatically, triggering the first peak. On the other hand

  9. Flagella-induced immunity against experimental cholera in adult rabbits.

    Science.gov (United States)

    Yancey, R J; Willis, D L; Berry, L J

    1979-07-01

    The adult rabbit ligated ileal loop model was used to evaluate the prophylactic potential of a crude flagellar (CF) vaccine produced from the classical. Inaba strain CA401. A greater than 1,000-fold increase in the challenge inoculum was required to induce an intestinal fluid response in actively immunized adult rabbits equivalent to that produced in unimmunized animals. Similar protection was afforded against challenge with classical and El Tor biotypes of both Inaba and Ogawa serotypes. Highly virulent 35S-labeled vibrios were inhibited in their ability to associated with the intestinal mucosa of CF-immunized rabbits. The protection conferred by CF immunization was found to be superior to that of a commercial bivalent vaccine and also to that of glutaraldehyde-treated cholera toxoid. The critical immunogenic component of CF appears to be a flagella-derived protein. The immunogenicity of CF was destroyed by heat treatment, and absorption of CF-immune serum with aflagellated mutant vibrios did not diminish its ability to confer a high level of passive protection. The intestinal protection of CF-immunized rabbits was completely reversed by the introduction of both goat anti-rabbit immunoglobulins A and G, but by neither alone.

  10. CHLOROCOCCALES DE LA AMAZONIA COLOMBIANA I: Chlorellaceae y Scenedesmaceae

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    ECHENIQUE RICARDO O.

    2004-06-01

    Full Text Available En este trabajo damos a conocer 41 taxones pertenecientes a las familias Chlorellaceaey Scenedesmaceae del orden Chlorococcales (Algae, Cholophyceae hallados entres cuencas de la Amazonia colombiana: Amazonas (Solimões, Putumayo (Içã yCaquetá (Japurá. Del total encontrado, 19 son nuevas citas para Colombia, nueveson nuevos registros para la cuenca en estudio y se propone una nueva entidadtaxonómica Tetraedron triangulare f. major Echenique nova forma. La mayor riquezase encontró en los lagos de inundación del río Amazonas, en particular en el lagoYahuarcaca que presenta amplio desarrollo de macrófitos y los mayores nivelestróficos de la región.

  11. Drug tourism or spiritual healing? Ayahuasca seekers in Amazonia.

    Science.gov (United States)

    Winkelman, Michael

    2005-06-01

    This research addresses the question of whether Westerners who seek traditional spiritual medicine known as ayahuasca can be best characterized as "drug tourists" or as people pursuing spiritual and therapeutic opportunities. Participants in an ayahuasca retreat in Amazonia were interviewed regarding their motivations for participation and the benefits they felt that they received. These findings from the interviews were organized to reveal common motivations and benefits. Contrary to the characterization as "drug tourists", the principal motivations can be characterized as: seeking spiritual relations and personal spiritual development; emotional healing; and the development of personal self-awareness, including contact with a sacred nature, God, spirits and plant and natural energies produced by the ayahuasca. The motivation and perceived benefits both point to transpersonal concerns, with the principal perceived benefits involving increased self awareness, insights and access to deeper levels of the self that enhanced personal development and the higher self, providing personal direction in life.

  12. Pervasive Rise of Small-scale Deforestation in Amazonia.

    Science.gov (United States)

    Kalamandeen, Michelle; Gloor, Emanuel; Mitchard, Edward; Quincey, Duncan; Ziv, Guy; Spracklen, Dominick; Spracklen, Benedict; Adami, Marcos; Aragão, Luiz E O C; Galbraith, David

    2018-01-25

    Understanding forest loss patterns in Amazonia, the Earth's largest rainforest region, is critical for effective forest conservation and management. Following the most detailed analysis to date, spanning the entire Amazon and extending over a 14-year period (2001-2014), we reveal significant shifts in deforestation dynamics of Amazonian forests. Firstly, hotspots of Amazonian forest loss are moving away from the southern Brazilian Amazon to Peru and Bolivia. Secondly, while the number of new large forest clearings (>50 ha) has declined significantly over time (46%), the number of new small clearings (<1 ha) increased by 34% between 2001-2007 and 2008-2014. Thirdly, we find that small-scale low-density forest loss expanded markedly in geographical extent during 2008-2014. This shift presents an important and alarming new challenge for forest conservation, despite reductions in overall deforestation rates.

  13. Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae: effects of insert position and host background

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, B; Pallesen, L; Jensen, LB

    1997-01-01

    . Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...... with respect to host background in three different Escherichia coli strains, i.e. an isogenic set of K-12 strains, differing in the presence of an indigenous fim gene cluster, as well as a wild-type isolate. Immunization of rabbits with purified chimeric fimbriae resulted in serum which specifically recognized...

  14. Cholera in travelers: shifting tides in epidemiology, management, and prevention.

    Science.gov (United States)

    Fillion, Katie; Mileno, Maria D

    2015-01-01

    The distribution of cholera's devastating effects has changed. While cholera is endemic in 50 countries mostly in Asia and Africa, more than half of the cases reported in 2012 were in the Western Hemisphere, predominantly Haiti. Since the current epidemic began in Haiti in 2010, there has been spread to the Dominican Republic, Cuba, and most recently Mexico. Several recent case reports document individuals returning home from affected areas with diarrhea from cholera, in some cases severe. Hopeful news reported the containment of an outbreak through the use of a Vibrio cholera vaccine. There are safe and effective oral cholera vaccines available and recommended in outbreaks and endemic areas, although they are not currently available in the USA or to travelers. This review aims to discuss the latest data to aid our current recommendations for the prevention of cholera in travelers beyond standard personal and food hygiene precautions for the prevention of travelers' diarrhea and to offer insights on the most current data available about cholera vaccine progress and potential use.

  15. Distribution of resistance genetic determinants among Vibrio cholerae isolates of 2012 and 2013 outbreaks in IR Iran.

    Science.gov (United States)

    Rezaie, Niloofar; Bakhshi, Bita; Najar-Peerayeh, Shahin

    2017-03-01

    The objective of this study was to characterize antimicrobial resistance determinants in relation to antimicrobial susceptibility and genotyping profile in 20 clinical isolates of Vibrio cholerae. All of the isolates were resistant to streptomycin. The second most prevalent resistance was observed to trimethoprim (75%), co-trimoxazole (60%), tetracycline (50%), and minocycline (45%). About 50% of the isolates fulfilled the criteria of Multi Drug Resistance (MDR) phenotype. None of the isolates carried tet A, B, C, and, D determinants. This finding shows that tetracycline resistance determinants recognized so far, does not satisfactorily describe the 50% tetracycline resistance phenotype in this study, suggesting the possible contribution of other not yet characterized resistance mechanisms involved. Class 1 integron, widely distributed among enteric bacteria, was not detected among V. cholerae strains under study. Conversely, 100% of the isolates harbored SXT constin (int) , among which 70% were positive for dfrA1, strA, and strB genes. The sul1gene was present in 60% of the isolates while none of them contained floR gene. All the isolates uniformly appeared to be identical in fingerprinting profiles expected from outbreak strains. In conclusion, SXT element with its mosaic structure was the exclusive antimicrobial resistance determinant of clonal V. cholerae isolates taken from outbreaks of 2012 and 2013 in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. USOS DE LAS PALMAS EN LA AMAZONIA COLOMBIANA

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    LAURA MESA

    2013-12-01

    Full Text Available Con el fin de obtener un diagnóstico del estado actual de conocimiento sobre usos de las palmas en la Amazonia colombiana, se revisaron las principales fuentes de información. Treinta y seis de las 41 etnias indígenas consideradas tuvieron registros de uso. Se registraron 82 especies de palmas usadas (78% de las potenciales y 165 usos distribuidos en ocho categorías; todos los usos se presentan de manera detallada en un catálogo. Las categorías de uso más importantes fueron: utensilios y herramientas, construcción, y alimentación humana. Las diez especies más importantes fueron Bactris gasipaes, Euterpe precatoria, Mauritia flexuosa, Oenocarpus bataua, Attalea maripa, Oenocarpus minor, Astrocaryum chambira, Iriartea deltoidea, Oenocarpus bacaba y Socratea exorrhiza; la mayoría de ellas también han sido registradas como las más importantes en otras partes del Neotrópico. No se encontró ninguna información sobre usos de palmas para varios grupos indígenas, especialmente para las etnias cocama, letuama, piaroa, pisamira y yurí, para las cuales se requieren investigaciones detalladas. Se concluye que a pesar de los vacíos de información, los resultados muestran que las palmas son un recurso muy importante con un gran potencial, y una pieza fundamental para la seguridad alimentaria y el desarrollo sustentable de la Amazonia colombiana. Sugerimos la inclusión de las especies más importantes en programas de manejo y agroforestales, al igual que la implementación y popularización de técnicas de cosecha no destructivas. Recomendamos además que las investigaciones futuras estén enfocadas en desarrollar estrategias de manejo que garanticen el uso sostenible de todas estas especies útiles.

  17. Marine intervals in Neogene fluvial deposits of western Amazonia

    Science.gov (United States)

    Boonstra, Melanie; Troelstra, Simon; Lammertsma, Emmy; Hoorn, Carina

    2014-05-01

    Amazonia is one of the most species rich areas on Earth, but this high diversity is not homogeneous over the entire region. Highest mammal and tree-alpha diversity is found in the fluvio-lacustrine Pebas system, a Neogene wetland associated with rapid radiation of species. The estuarine to marine origin of various modern Amazonian fish, plants, and invertebrates has been associated with past marine ingressions into this freshwater Pebas system. The exact nature and age of these invasions is, however, debated. Here we present new evidence from fluvial and fluvio-lacustrine deposits of Neogene age in southeast Colombia, that point to periods of widespread marine conditions in western Amazonia. Our evidence is based on an analysis of marine palynomorphs, such as organic linings of foraminifera and dinoflagellate cysts, present in dark sandy clay sediments that outcrop along the Caqueta and Amazon rivers. Characteristically, the foraminiferal linings can be assigned to three benthic morphotypes only, e.g. Ammonia, Elphidium and Trochammina. This low diversity assemblage is associated with estuarine/marginal marine conditions. No distinct marine elements such as shelf or planktonic species were encountered. The observed foraminiferal linings and dinocyst assemblages are typical for a (eutrophic) shallow marine environment, suggesting that the Pebas freshwater wetland system occasionally changed to (marginal) marine. Although some reworked elements are found, a typical Neogene dinocyst taxon is commonly found supporting in situ deposition. Sedimentological features typical for tidal conditions that are reported for sites in Peru and northeastern Brazil likely relate to these marine ingressions. Sea level changes as well as foreland basin development related to Andes formation may have facilitated the entry of marine water during the Neogene.

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

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    Guillaume Constantin de Magny

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

  19. Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins

    International Nuclear Information System (INIS)

    Kaslow, H.R.; Groppi, V.E.; Abood, M.E.; Bourne, H.R.

    1981-01-01

    Cholera toxin catalyzes transfer of radiolabel from [ 32 P]NAD + to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and [ 32 P]NAD + caused radiolabeling of purified microtubule and intermediate filament proteins

  20. The Orphans of Cholera Morbus in Yucatan, 1833

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    Elsa Malvido

    2013-07-01

    Full Text Available This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socially privileged groups to get hold of free labor force both for domestic service and hacienda work.

  1. Cholera in pregnancy: outcomes from a specialized cholera treatment unit for pregnant women in Léogâne, Haiti.

    Science.gov (United States)

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

    2013-01-01

    The association between cholera in pregnancy and negative fetal outcome has been described since the 19(th) century. However, there is limited published literature on the subject. We describe pregnancy outcomes from a specialized multidisciplinary hospital unit at the onset of a large cholera outbreak in Haiti in 2010 and 2011. Pregnant women with cholera were hospitalized in a specialized unit within the MSF hospital compound in Léogâne and treated using standard cholera treatment guidelines but with earlier, more intense fluid replacement. All women had intravenous access established at admission regardless of their hydration status, and all received antibiotic treatment. Data were collected on patient demographics, pregnancy and cholera status, and pregnancy outcome. In this analysis we calculated risk ratios for fetal death and performed logistic regression analysis to control for confounding factors. 263 pregnant women with cholera were hospitalized between December 2010 and July 2011. None died during hospitalization, 226 (86%) were discharged with a preserved pregnancy and 16 (6%) had live fullterm singleton births, of whom 2 died within the first 5 days postpartum. The remaining 21 pregnancies (8%) resulted in intrauterine fetal death. The risk of fetal death was associated with factors reflecting severity of the cholera episode: after adjusting for confounding factors, the strongest risk factor for fetal death was severe maternal dehydration (adjusted risk ratio for severe vs. mild dehydration was 9.4, 95% CI 2.5-35.3, p = 0.005), followed by severe vomiting (adjusted risk ratio 5.1, 95% 1.1-23.8, p = 0.041). This is the largest cohort of pregnant women with cholera described to date. The main risk factor identified for fetal death was severity of dehydration. Our experience suggests that establishing specialized multidisciplinary units which facilitate close follow-up of both pregnancy and dehydration status due to cholera could be beneficial

  2. Exoproteome and Secretome Derived Broad Spectrum Novel Drug and Vaccine Candidates in Vibrio cholerae Targeted by Piper betel Derived Compounds

    Science.gov (United States)

    Barh, Debmalya; Barve, Neha; Gupta, Krishnakant; Chandra, Sudha; Jain, Neha; Tiwari, Sandeep; Leon-Sicairos, Nidia; Canizalez-Roman, Adrian; Rodrigues dos Santos, Anderson; Hassan, Syed Shah; Almeida, Síntia; Thiago Jucá Ramos, Rommel; Augusto Carvalho de Abreu, Vinicius; Ribeiro Carneiro, Adriana; de Castro Soares, Siomar; Luiz de Paula Castro, Thiago; Miyoshi, Anderson; Silva, Artur; Kumar, Anil; Narayan Misra, Amarendra; Blum, Kenneth; Braverman, Eric R.; Azevedo, Vasco

    2013-01-01

    Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species. PMID:23382822

  3. Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds.

    Directory of Open Access Journals (Sweden)

    Debmalya Barh

    Full Text Available Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC for most of the pathogenic Vibrio strains. Two targets (uppP and yajC are novel to Vibrio, and two targets (uppP and ompU can be used to develop both drugs and vaccines (dual targets against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

  4. Vibrio cholerae cytolysin causes an inflammatory response in human intestinal epithelial cells that is modulated by the PrtV protease.

    Directory of Open Access Journals (Sweden)

    Gangwei Ou

    Full Text Available BACKGROUND: Vibrio cholerae is the causal intestinal pathogen of the diarrheal disease cholera. It secretes the protease PrtV, which protects the bacterium from invertebrate predators but reduces the ability of Vibrio-secreted factor(s to induce interleukin-8 (IL-8 production by human intestinal epithelial cells. The aim was to identify the secreted component(s of V. cholerae that induces an epithelial inflammatory response and to define whether it is a substrate for PrtV. METHODOLOGY/PRINCIPAL FINDINGS: Culture supernatants of wild type V. cholerae O1 strain C6706, its derivatives and pure V. cholerae cytolysin (VCC were analyzed for the capacity to induce changes in cytokine mRNA expression levels, IL-8 and tumor necrosis factor-alpha (TNF-alpha secretion, permeability and cell viability when added to the apical side of polarized tight monolayer T84 cells used as an in vitro model for human intestinal epithelium. Culture supernatants were also analyzed for hemolytic activity and for the presence of PrtV and VCC by immunoblot analysis. CONCLUSIONS/SIGNIFICANCE: We suggest that VCC is capable of causing an inflammatory response characterized by increased permeability and production of IL-8 and TNF-alpha in tight monolayers. Pure VCC at a concentration of 160 ng/ml caused an inflammatory response that reached the magnitude of that caused by Vibrio-secreted factors, while higher concentrations caused epithelial cell death. The inflammatory response was totally abolished by treatment with PrtV. The findings suggest that low doses of VCC initiate a local immune defense reaction while high doses lead to intestinal epithelial lesions. Furthermore, VCC is indeed a substrate for PrtV and PrtV seems to execute an environment-dependent modulation of the activity of VCC that may be the cause of V. cholerae reactogenicity.

  5. Epidemiology of the 2016 Cholera Outbreak of Chibombo District ...

    African Journals Online (AJOL)

    the 11 water samples available 2 (18%) were found to have faeces ... awareness of cholera transmission whenever the country ... It's transmitted by the faeco-oral route. Although most ... There was limited spread of disease among clusters of.

  6. Assessment of Risk of Cholera in Haiti following Hurricane Matthew.

    Science.gov (United States)

    Khan, Rakib; Anwar, Rifat; Akanda, Shafqat; McDonald, Michael D; Huq, Anwar; Jutla, Antarpreet; Colwell, Rita

    2017-09-01

    Damage to the inferior and fragile water and sanitation infrastructure of Haiti after Hurricane Matthew has created an urgent public health emergency in terms of likelihood of cholera occurring in the human population. Using satellite-derived data on precipitation, gridded air temperature, and hurricane path and with information on water and sanitation (WASH) infrastructure, we tracked changing environmental conditions conducive for growth of pathogenic vibrios. Based on these data, we predicted and validated the likelihood of cholera cases occurring past hurricane. The risk of cholera in the southwestern part of Haiti remained relatively high since November 2016 to the present. Findings of this study provide a contemporary process for monitoring ground conditions that can guide public health intervention to control cholera in human population by providing access to vaccines, safe WASH facilities. Assuming current social and behavioral patterns remain constant, it is recommended that WASH infrastructure should be improved and considered a priority especially before 2017 rainy season.

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

    Science.gov (United States)

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

    2013-01-01

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

  8. 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 ...

  9. 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.

  10. Successful Multi-partner Response to a Cholera Outbreak

    African Journals Online (AJOL)

    46987.2

    World Health Organisation,. Country Office ... a global threat to public health and a key indicator of inadequate .... While the cholera outbreak in Lusaka was first reported in. Kanyama ... restaurants, markets, schools and other public places of.

  11. Co-variation of Cholera with Climatic and Environmental Parameters ...

    African Journals Online (AJOL)

    adjusted cholera cases and coastal ocean chlorophyll a and, to some degree, sea surface temperature, the ... environmental variables, such as air and water temperature, rainfall ... nutrients and plankton biomass (Vezulli et al., 2010). Water ...

  12. 7. Factors Associated With the Recurring Cholera Outbreaks in ...

    African Journals Online (AJOL)

    46987.2

    analysis was performed to control for confounders. Results:There was a ..... their household, however, the sewer system, flush/pour ... and environmental data from cholera-endemic areas of Zanzibar .... food served on an international aircraft,.

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

    Directory of Open Access Journals (Sweden)

    Keegan J. Baldauf

    2015-03-01

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

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

    Science.gov (United States)

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

    2012-12-01

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

  15. Response to the cholera outbreak in South Sudan

    African Journals Online (AJOL)

    On Thursday, May 15th 2014, the Ministry of Health (MoH) of the Republic of South Sudan declared a cholera outbreak in the capital Juba. As we go to press, the cholera has spread to other parts of the country and the cases are increasing. In its press statement, the MoH said it had “Reactivated a national emergency ...

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

    Science.gov (United States)

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

    2013-01-01

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

  17. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    John Benktander

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

  18. Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers.

    Science.gov (United States)

    Kunkel, Amber; Lewnard, Joseph A; Pitzer, Virginia E; Cohen, Ted

    2017-08-01

    More than 5 years after a United Nations peacekeeping battalion introduced cholera to Haiti, over 150,000 peacekeepers continue to be deployed annually from countries where cholera is endemic. The United Nations has thus far declined to provide antimicrobial chemoprophylaxis to peacekeepers, a policy based largely on concerns that the risks of drug resistance generation and spread would outweigh the potential benefits of preventing future cholera importations. In this study, we sought to better understand the relative benefits and risks of cholera chemoprophylaxis for peacekeepers in terms of antibiotic resistance. Using a stochastic model to quantify the potential impact of chemoprophylaxis on importation and transmission of drug-resistant and drug-sensitive Vibrio cholerae , we found that chemoprophylaxis would decrease the probability of cholera importation but would increase the expected number of drug-resistant infections if an importation event were to occur. Despite this potential increase, we found that at least 10 drug-sensitive infections would likely be averted per excess drug-resistant infection under a wide range of assumptions about the underlying prevalence of drug resistance and risk of acquired resistance. Given these findings, policymakers should reconsider whether the potential resistance risks of providing antimicrobial chemoprophylaxis to peacekeepers are sufficient to outweigh the anticipated benefits. Copyright © 2017 American Society for Microbiology.

  19. Distribution ofVibrio cholerae in two Florida estuaries.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries.

  20. ANTAGONISM AGAINST VIBRIO CHOLERAE BY BACTERIAL DIFFUSIBLE COMPOUND IN THE FECAL MICROBIOTA OF RODENTS

    Directory of Open Access Journals (Sweden)

    Silva Simone Helena da

    1998-01-01

    Full Text Available In an ex vivo agar plate assay, we monitored the appearance of an inhibitory halo against Vibrio cholerae from the feces of Wistar and Fischer rats aged 10 to 42 days. The frequency of Wistar rats showing halo increased from 0% (10 days to a maximum of 80.0% (29 days and then decreased to 53.3% (42 days. A similar pattern was obtained with Fischer rats but with a lower intensity (maximum frequency of 50.0% by day 36. In a separate experiment, when Wistar rats were fed a low-protein diet for 7 days, the inhibitory halo decreased drastically. Three apparently different colony morphologies were isolated from the dominant fecal microbiota: a facultative anaerobe (FAN and two strict anaerobes (SAN. The ex vivo inhibitory test showed a halo around the feces of germfree mice monoassociated with the FAN bacterium or one of the SAN bacterium but not of the germfree ones. After oral challenge of all groups with V. cholerae, a permissive and a drastic barrier effects were observed in mice with FAN and SAN associated bacteria, respectively. The FAN and one SAN bacteria used in the in vivo challenges were identified as Escherichia coli and Streptococcus intermedius, respectively. The potent antagonism developed by the rat intestinal microbiota against V. cholerae seems to be due, in part, to diffusible compounds and this phenomenon depends apparently on age, strain and nutrition of the animals. These preliminary results also suggest that this effect was due to more than one bacterial component at any given moment.

  1. 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)

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

    Directory of Open Access Journals (Sweden)

    Luque Fernandez Miguel A

    2012-06-01

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

  3. 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

  4. Cholera Outbreaks in Urban Bangladesh In 2011.

    Science.gov (United States)

    Haque, Farhana; Hossain, M Jahangir; Kundu, Subodh Kumar; Naser, Abu Mohd; Rahman, Mahmudur; Luby, Stephen P

    In 2011, a multidisciplinary team investigated two diarrhoea outbreaks affecting urban Bangladeshi communities from the districts of Bogra and Kishorganj to identify etiology, pathways of transmission, and factors contributing to these outbreaks. We defined case-patients with severe diarrhoea as residents from affected communities admitted with ≥3 loose stools per day. We listed case-patients, interviewed and examined them, and collected rectal swabs. We visited the affected communities to explore the water and sanitation infrastructure. We tested the microbial load of water samples from selected case household taps, tube wells, and pump stations. We conducted anthropological investigations to understand community perceptions regarding the outbreaks. We identified 21 case-patients from Bogra and 84 from Kishorganj. The median age in Bogra was 23 years, and 21 years in Kishorganj. There were no reported deaths. We isolated Vibrio in 29% (5/17) of rectal swabs from Bogra and in 40% (8/20) from Kishorganj. We found Vibrio in 1/8 tap water samples from Bogra and in both of the samples from Kishorganj. We did not find Vibrio in water samples from pumps or tube wells in either outbreak. Ground water extracted through deep tube wells was supplied intermittently through interconnected pipes without treatment in both areas. We found leakages in the water pipes in Bogra, and in Kishorganj water pipes passed through open sewers. The rapid onset of severe diarrhoea predominantly affecting adults and the isolation of cholera in rectal swabs confirmed that these outbreaks were caused by Vibrio cholerae . The detection of Vibrio in water samples organisms from taps but not from pumps or tube wells, suggested contamination within the pipes. Safe water provision is difficult in municipalities where supply is intermittent, and where pipes commonly leak. Research to develop and evaluate water purification strategies could identify appropriate approaches for ensuring safe drinking

  5. Characterization of VCC-1, a Novel Ambler Class A Carbapenemase from Vibrio cholerae Isolated from Imported Retail Shrimp Sold in Canada.

    Science.gov (United States)

    Mangat, Chand S; Boyd, David; Janecko, Nicol; Martz, Sarah-Lynn; Desruisseau, Andrea; Carpenter, Michael; Reid-Smith, Richard J; Mulvey, Michael R

    2016-01-11

    One of the core goals of the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) is to monitor major meat commodities for antimicrobial resistance. Targeted studies with methodologies based on core surveillance protocols are used to examine other foods, e.g., seafood, for antimicrobial resistance to detect resistances of concern to public health. Here we report the discovery of a novel Ambler class A carbapenemase that was identified in a nontoxigenic strain of Vibrio cholerae (N14-02106) isolated from shrimp that was sold for human consumption in Canada. V. cholerae N14-02106 was resistant to penicillins, carbapenems, and monobactam antibiotics; however, PCR did not detect common β-lactamases. Bioinformatic analysis of the whole-genome sequence of V. cholerae N14-02106 revealed on the large chromosome a novel carbapenemase (referred to here as VCC-1, for Vibrio cholerae carbapenemase 1) with sequence similarity to class A enzymes. Two copies of blaVCC-1 separated and flanked by ISVch9 (i.e., 3 copies of ISVch9) were found in an acquired 8.5-kb region inserted into a VrgG family protein gene. Cloned blaVCC-1 conferred a β-lactam resistance profile similar to that in V. cholerae N14-02106 when it was transformed into a susceptible laboratory strain of Escherichia coli. Purified VCC-1 was found to hydrolyze penicillins, 1st-generation cephalosporins, aztreonam, and carbapenems, whereas 2nd- and 3rd-generation cephalosporins were poor substrates. Using nitrocefin as a reporter substrate, VCC-1 was moderately inhibited by clavulanic acid and tazobactam but not EDTA. In this report, we present the discovery of a novel class A carbapenemase from the food supply. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

    2013-01-01

    Background Cholera mainly affects developing countries where safe water supply and sanitation infrastructure are often rudimentary. Sub-Saharan Africa is a cholera hotspot. Effective cholera control requires not only a professional assessment, but also consideration of community-based priorities. The present work compares local sociocultural features of endemic cholera in urban and rural sites from three field studies in southeastern Democratic Republic of Congo (SE-DRC), western Kenya and Zanzibar. Methods A vignette-based semistructured interview was used in 2008 in Zanzibar to study sociocultural features of cholera-related illness among 356 men and women from urban and rural communities. Similar cross-sectional surveys were performed in western Kenya (n = 379) and in SE-DRC (n = 360) in 2010. Systematic comparison across all settings considered the following domains: illness identification; perceived seriousness, potential fatality and past household episodes; illness-related experience; meaning; knowledge of prevention; help-seeking behavior; and perceived vulnerability. Results Cholera is well known in all three settings and is understood to have a significant impact on people’s lives. Its social impact was mainly characterized by financial concerns. Problems with unsafe water, sanitation and dirty environments were the most common perceived causes across settings; nonetheless, non-biomedical explanations were widespread in rural areas of SE-DRC and Zanzibar. Safe food and water and vaccines were prioritized for prevention in SE-DRC. Safe water was prioritized in western Kenya along with sanitation and health education. The latter two were also prioritized in Zanzibar. Use of oral rehydration solutions and rehydration was a top priority everywhere; healthcare facilities were universally reported as a primary source of help. Respondents in SE-DRC and Zanzibar reported cholera as affecting almost everybody without differentiating much for gender, age

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

    DEFF Research Database (Denmark)

    Qureshi, Katja; Mølbak, Kåre; Sandström, Anita

    2006-01-01

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

  8. Uptake of Vibrio cholerae biotype eltor from contaminated water by water hyacinth (eichornia crassipes).

    Science.gov (United States)

    Spira, W M; Huq, A; Ahmed, Q S; Saeed, Y A

    1981-09-01

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

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

    OpenAIRE

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

    1981-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Electric systems failures produced by CG lightning in Eastern Amazonia

    Directory of Open Access Journals (Sweden)

    Ana Paula Paes dos Santos

    2014-12-01

    Full Text Available Operational records of power outages of the electric energy distribution systems in eastern Amazonia presented a large number of events attributed to lightning strikes, during the 2006 to 2009 period. The regional electricity concessionary data were compared to actual lightning observations made by SIPAM's LDN system, over two areas where operational sub systems of transmission lines are installed. Statistical relations were drawn between the monthly lightning occurrence density and the number of power outages of the electric systems for both areas studied. The results showed that, although with some delays between these variables peaks, the number of power disruptions has a tendency to follow the behavior of the lightning occurrence densities variations. The numerical correlations were positive and may be useful to the transmission lines maintenance crews at least for the Belém-Castanhal electricity distribution sub system. Evidence was found, that the SST's over certain areas of the Pacific and Atlantic Oceans, influence convection over the area of interest, and may help to prognosticate the periods of intense electric storms, requiring repair readiness for the regional electric systems.

  12. Biome-Scale Forest Properties in Amazonia Based on Field and Satellite Observations

    Directory of Open Access Journals (Sweden)

    Liana O. Anderson

    2012-05-01

    Full Text Available Amazonian forests are extremely heterogeneous at different spatial scales. This review intends to present the large-scale patterns of the ecosystem properties of Amazonia, and focuses on two parts of the main components of the net primary production: the long-lived carbon pools (wood and short-lived pools (leaves. First, the focus is on forest biophysical properties, and secondly, on the macro-scale leaf phenological patterns of these forests, looking at field measurements and bringing into discussion the recent findings derived from remote sensing dataset. Finally, I discuss the results of the three major droughts that hit Amazonia in the last 15 years. The panorama that emerges from this review suggests that slow growing forests in central and eastern Amazonia, where soils are poorer, have significantly higher above ground biomass and higher wood density, trees are higher and present lower proportions of large-leaved species than stands in northwest and southwest Amazonia. However, the opposite pattern is observed in relation to forest productivity and dynamism, which is higher in western Amazonia than in central and eastern forests. The spatial patterns on leaf phenology across Amazonia are less marked. Field data from different forest formations showed that new leaf production can be unrelated to climate seasonality, timed with radiation, timed with rainfall and/or river levels. Oppositely, satellite images exhibited a large-scale synchronized peak in new leaf production during the dry season. Satellite data and field measurements bring contrasting results for the 2005 drought. Discussions on data processing and filtering, aerosols effects and a combined analysis with field and satellite images are presented. It is suggested that to improve the understanding of the large-scale patterns on Amazonian forests, integrative analyses that combine new technologies in remote sensing and long-term field ecological data are imperative.

  13. 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...

  14. 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.

  15. Development of pVCR94ΔX from Vibrio cholerae, a prototype for studying multidrug resistant IncA/C conjugative plasmids.

    Science.gov (United States)

    Carraro, Nicolas; Sauvé, Maxime; Matteau, Dominick; Lauzon, Guillaume; Rodrigue, Sébastien; Burrus, Vincent

    2014-01-01

    Antibiotic resistance has grown steadily in Vibrio cholerae over the last few decades to become a major threat in countries affected by cholera. Multi-drug resistance (MDR) spreads among clinical and environmental V. cholerae strains by lateral gene transfer often mediated by integrative and conjugative elements (ICEs) of the SXT/R391 family. However, in a few reported but seemingly isolated cases, MDR in V. cholerae was shown to be associated with other self-transmissible genetic elements such as conjugative plasmids. IncA/C conjugative plasmids are often found associated with MDR in isolates of Enterobacteriaceae. To date, IncA/C plasmids have not been commonly found in V. cholerae or other species of Vibrio. Here we present a detailed analysis of pVCR94ΔX derived from pVCR94, a novel IncA/C conjugative plasmid identified in a V. cholerae clinical strain isolated during the 1994 Rwandan cholera outbreak. pVCR94 was found to confer resistance to sulfamethoxazole, trimethoprim, ampicillin, streptomycin, tetracycline, and chloramphenicol and to transfer at very high frequency. Sequence analysis revealed its mosaic nature as well as high similarity of the core genes responsible for transfer and maintenance with other IncA/C plasmids and ICEs of the SXT/R391 family. Although IncA/C plasmids are considered a major threat in antibiotics resistance, their basic biology has received little attention, mostly because of the difficulty to genetically manipulate these MDR conferring elements. Therefore, we developed a convenient derivative from pVCR94, pVCR94Δ X, a 120.5-kb conjugative plasmid which only codes for sulfamethoxazole resistance. Using pVCR94Δ X, we identified the origin of transfer (oriT) and discovered an essential gene for transfer, both located within the shared backbone, allowing for an annotation update of all IncA/C plasmids. pVCR94Δ X may be a useful model that will provide new insights on the basic biology of IncA/C conjugative plasmids.

  16. Development and testing of monoclonal antibody-based rapid immunodiagnostic test kits for direct detection of Vibrio cholerae O139 synonym Bengal.

    Science.gov (United States)

    Hasan, J A; Huq, A; Nair, G B; Garg, S; Mukhopadhyay, A K; Loomis, L; Bernstein, D; Colwell, R R

    1995-11-01

    We report on the development and testing of two monoclonal antibody-based rapid immunodiagnostic test kits, BengalScreen, a coagglutination test, and Bengal DFA, a direct fluorescent-antibody test, for direct detection of Vibrio cholerae O139 synonym Bengal in clinical and environmental specimens. The BengalScreen test requires less than 5 min to complete and can be used in the field. Bengal DFA, being more sensitive than BengalScreen, requires only one reagent and less than 20 min for detection and enumeration of V. cholerae O139 synonym Bengal. In tests for specificity, all 40 strains of V. cholerae O139 reacted with both test kits, whereas 157 strains of heterologous species examined did not, yielding 100% specificity in this study. A field trial was conducted in with both BengalScreen and Bengal DFA, and the results were compared with those obtained by conventional culture methods. BengalScreen demonstrated a sensitivity of 95%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 94%. Results obtained by Bengal DFA, on the other hand, were 100% sensitive and 100% specific and yielded 100% positive and negative predictive values compared with culture methods. In a second evaluation, 93 stool specimens from Mexico that were negative for V. cholerae O139 by culture were also tested with both the BengalScreen and Bengal DFA kits. None of the 93 specimens were positive for V. cholerae O139 by both tests. A concentration method was optimized for screening of environmental water samples for V. cholerae O139 synonym Bengal with rapid test kits. BengalScreen results were unequivocally positive when water samples contained at least 2.0 x 10(3) CFU/ml, whereas Bengal DFA demonstrated an unequivocally positive reaction when the water sample contained at least 1.5 x 10(2) CFU/ml. When Bengal DFA was compared with conventional culture methods for enumeration of V. cholerae O139 synonym Bengal organisms, no difference was observed.

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

    Science.gov (United States)

    Baharoglu, Zeynep; Krin, Evelyne; Mazel, Didier

    2013-01-01

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

  18. 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.

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

    Science.gov (United States)

    Stamm-Kuhlmann, T

    1989-01-01

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

  20. 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.

  1. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned and...

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

    Science.gov (United States)

    Schultz, Colin

    2014-09-01

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

  3. 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.

  4. Epidemic Cholera in a Crowded Urban Environment, Port-au-Prince, Haiti

    OpenAIRE

    Dunkle, Stacie E.; Mba-Jonas, Adamma; Loharikar, Anagha; Fouché, Bernadette; Peck, Mireille; Ayers, Tracy; Archer, W. Roodly; De Rochars, Valery M. Beau; Bender, Thomas; Moffett, Daphne B.; Tappero, Jordan W.; Dahourou, George; Roels, Thierry H.; Quick, Robert

    2011-01-01

    We conducted a case–control study to investigate factors associated with epidemic cholera. Water treatment and handwashing may have been protective, highlighting the need for personal hygiene for cholera prevention in contaminated urban environments. We also found a diverse diet, a possible proxy for improved nutrition, was protective against cholera.

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

    Directory of Open Access Journals (Sweden)

    C. Bidinost

    2004-12-01

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

  6. Natural Disasters and Cholera Outbreaks: Current Understanding and Future Outlook.

    Science.gov (United States)

    Jutla, Antarpreet; Khan, Rakibul; Colwell, Rita

    2017-03-01

    Diarrheal diseases remain a serious global public health threat, especially for those populations lacking access to safe water and sanitation infrastructure. Although association of several diarrheal diseases, e.g., cholera, shigellosis, etc., with climatic processes has been documented, the global human population remains at heightened risk of outbreak of diseases after natural disasters, such as earthquakes, floods, or droughts. In this review, cholera was selected as a signature diarrheal disease and the role of natural disasters in triggering and transmitting cholera was analyzed. Key observations include identification of an inherent feedback loop that includes societal structure, prevailing climatic processes, and spatio-temporal seasonal variability of natural disasters. Data obtained from satellite-based remote sensing are concluded to have application, although limited, in predicting risks of a cholera outbreak(s). We argue that with the advent of new high spectral and spatial resolution data, earth observation systems should be seamlessly integrated in a decision support mechanism to be mobilize resources when a region suffers a natural disaster. A framework is proposed that can be used to assess the impact of natural disasters with response to outbreak of cholera, providing assessment of short- and long-term influence of climatic processes on disease outbreaks.

  7. On the probability of extinction of the Haiti cholera epidemic

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

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

    1987-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Afzali H.MD,

    2016-03-01

    Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

  10. Case studies in cholera: lessons in medical history and science.

    Science.gov (United States)

    Kavic, S. M.; Frehm, E. J.; Segal, A. S.

    1999-01-01

    Cholera, a prototypical secretory diarrheal disease, is an ancient scourge that has both wrought great suffering and taught many valuable lessons, from basic sanitation to molecular signal transduction. Victims experience the voluminous loss of bicarbonate-rich isotonic saline at a rate that may lead to hypovolemic shock, metabolic acidosis, and death within afew hours. Intravenous solution therapy as we know it was first developed in an attempt to provide life-saving volume replacement for cholera patients. Breakthroughs in epithelial membrane transport physiology, such as the discovery of sugar and salt cotransport, have paved the way for oral replacement therapy in areas of the world where intravenous replacement is not readily available. In addition, the discovery of the cholera toxin has yielded vital information about toxigenic infectious diseases, providing a framework in which to study fundamental elements of intracellular signal transduction pathways, such as G-proteins. Cholera may even shed light on the evolution and pathophysiology of cystic fibrosis, the most commonly inherited disease among Caucasians. The goal of this paper is to review, using case studies, some of the lessons learned from cholera throughout the ages, acknowledging those pioneers whose seminal work led to our understanding of many basic concepts in medical epidemiology, microbiology, physiology, and therapeutics. PMID:11138935

  11. Oral cholera vaccine--for whom, when, and why?

    Science.gov (United States)

    Topps, Maureen H

    2006-01-01

    The search for a safe, effective, well tolerated, low cost vaccine against the ancient cholera enemy has been ongoing since the 19th century and has been revitalized in the past two decades since the advent of recombinant technology. Large-scale field trials have readily demonstrated the tolerability and safety of oral cholera vaccine in various forms. Variable levels of protection have been shown and one challenge has been to demonstrate whether this is a cost effective treatment in differing environments including its use in endemic and epidemic areas as well as for travelers. A review of recent literature was undertaken to assess the effectiveness and uses of currently available oral cholera vaccine. While the evidence does not support the creation of formal guidelines, some clear recommendations can be made. There is undoubtedly the potential to reduce the burden of illness both in endemic and epidemic situations. For travelers, certain higher risk groups may benefit from protection against cholera. More significantly, the short term cross-protection afforded by whole cell, B subunit (WC BS) oral cholera vaccine formulations against enterotoxigenic E. coli, (ETEC), the commonest causative agent of traveler's diarrhoea, may prove to be the most important raison d'être.

  12. In vitro antibacterial activity of methanol and water extracts of adiantum capillus veneris and tagetes patula against multidrug resistant bacterial strains

    International Nuclear Information System (INIS)

    Hussain, M.M.; Ahmad, B.; Bashid, E.; Hashim, S.

    2014-01-01

    The aim of present study was to screen the antimicrobial activities of extracts of leaves and stems of Adiantum capillus veneris and Tagetes patula against multidrug-resistant (MDR) bacterial strains. Extracts from the leaves and stems of these plants were extracted with methanol and water and tested for their antibacterial activity by disc diffusion method against ten MDR bacterial strains i.e., Citrobacter freundii, Escherichia coli, Providencia, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella and Vibrio cholerae. Leaves methanol extract (LME) of Adiantum showed maximum Zone of Inhibition (ZI) against Providencia, Klebsiella pneumoniae, Shigella, Vibrio cholerae, Staphylococcus aureus, Proteus vulgaris and Salmonella typhi, whereas its stem methanol extract (SME) was very active against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi. Similarly LME of Tagetes showed highest ZI against Escherichia coli and Vibrio cholerae while SME showed highest ZI to Escherichia coli, Vibrio cholerae, Providencia, Shigella and Klebsiella pneumoniae. Leaves water extract (LWE) of Adiantum was very active against all ten bacterial strains while its stem water extract (SWE) showed maximum ZI against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi, Shigella, Proteus vulgaris and Providencia. LWE of Tagetes was only active against Vibrio cholerae whereas SWE was very active against Salmonella typhi and active against P. vulgaris, Citrobacter freundii and Vibrio cholerae. It was concluded from this study that extracts of both Adiantum and Tagetes have prominent activities against most of the MDR bacterial strains and needs further studies for utmost benefits. (author)

  13. 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

  14. Health impairments arising from drinking water resources contaminated with Vibrio cholerae.

    Science.gov (United States)

    Ramamurthy, T; Chakraborty, S; Nair, G B; Bhattacharya, S K

    2000-01-01

    The endemic and seasonal nature of cholera depends upon the survival of toxigenic Vibrio cholerae in various niches of the aquatic environment. To understand the transmission and ecology of V. cholerae, it is necessary to know which component in the aquatic ecosystem can harbor it and thus contribute to the endemic presence. Toxigenic V. cholerae is now recognized as an autochthonous member of the microflora in many aquatic environments based on its protracted survival and proliferation without losing the virulence determinants. This article summarizes knowledge about the ecology, survival strategies and elimination techniques of V. cholerae from natural waters with special reference to drinking water.

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

    Science.gov (United States)

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

    2015-12-01

    The severe diarrheal disease cholera is endemic in over 50 countries. Current therapies for cholera patients involve oral and/or intravenous rehydration, often combined with the use of antibiotics to shorten the duration and intensity of the disease. However, as antibiotic resistance increases, treatment options will become limited. Linoleic acid has been shown to be a potent negative effector of V. cholerae virulence that acts on the major virulence transcription regulator protein, ToxT, to inhibit virulence gene expression. ToxT activates transcription of the two major virulence factors required for disease, cholera toxin (CT) and toxin-coregulated pilus (TCP). A conjugated form of linoleic acid (CLA) is currently sold over the counter as a dietary supplement and is generally recognized as safe by the U.S. Food and Drug Administration. This study examined whether CLA could be used as a new therapy to reduce CT production, which, in turn, would decrease disease duration and intensity in cholera patients. CLA could be used in place of traditional antibiotics and would be very unlikely to generate resistance, as it affects only virulence factor production and not bacterial growth or survival. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. [Poland: cholera to typhus, 1831-1950].

    Science.gov (United States)

    Balinska, M A

    1999-12-01

    In this article devoted to Poland's direct and indirect role in the elaboration of contemporary international health structures and to her reputation as an epidemic reservoir of Europe, we consider how Poland came to be perceived as the cordon sanitaire of the West. Traditionally seen as upholding Western values, in the 19th and 20th centuries the country became increasingly associated with "Eastern plagues"-cholera and then typhus-coming from Russia and which could spread to the rest of Europe if Poland did not manage to contain them. When Poland was reconstituted as a nation-state in 1918, the new country won international recognition through her successful attempts to contain a typhus epidemic sweeping westwards from Russia. The Polish government convened the first European, League sponsored, health conference following the First World War. A Polish doctor, L. RAJCHMAN, was chosen to head up the League of Nations Health Organisation (forerunner of the WHO) and later (1946) founded UNICEF. Finally, we examine the key issue of exanthematous typhus in both world wars, exemplifying how a disease can come to be "ideologized", in this case by Nazi Germany. Typhus was the pretext used- in the name of "public health"-for segregating Polish citizens of Jewish origin and even killing them. Paradoxically, typhus was in the process of being eradicated when the war began and German policy of mass resettlements, sequestration, and starvation only spurred the epidemic they supposedly wished to control.

  17. A bibliography of references to avian cholera

    Science.gov (United States)

    Wilson, Sonoma S.

    1979-01-01

    Mrs. Wilson has made a genuine effort to include in this bibliography every significant reference to avian cholera since Louis Pasteur's articles appeared in 1880, although she recognizes the likelihood that a few have been overlooked. New listings have been added throughout 1978, but comprehensive coverage of the literature cannot be claimed beyond June of that year.Textbook accounts, because they are generally summaries of work published elsewhere, are excluded. Papers dealing primarily with the biology of Pasteurella multocida, as opposed to the disease it induces in birds, are also excluded, unless they report information of diagnostic usefulness. Short abstracts are not included unless the journals in which they are published are more widely available than those in which the complete articles appear or they are English summaries of foreign language articles.In compiling this bibliography, Mrs. Wilson has made extensive use of Biological Abstracts, the Pesticide Documentation Bulletin, and printouts generated by Bibliographic Retrieval Services, Inc. The "Literature Cited" sections of textbooks and journal articles pertinent to the subject were sources of many additional references. Regardless of the origin of the citation, its accuracy was confirmed by comparison with the original publication, except in those few instances (marked with an asterisk) when the journal was not on the shelves of the libraries accessible to us.The author will be grateful to users of the bibliography who point out errors or omissions.Wayne I. JensenMicrobiologist In Charge

  18. Respon Imun Anak Babi Pasca Vaksinasi Hog Cholera

    Directory of Open Access Journals (Sweden)

    I Made Jayanata

    2016-10-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh antibodi maternal terhadap titer antibodi anak babi yang di vaksin hog cholera umur 7 hari. Penelitian menggunakan tujuh sampel babi dari induk yang divaksin secara teratur yang diberikan perlakuan vaksinasi pada umur 7 hari. Pengambilan sampel serum dilakukan pravaksinasi (7 hari, dan satu minggu serta dua minggu pasca vaksinasi. Untuk menentukan titer antibodi virus Hog cholera pada sampel anak babi dilakukan uji ELISA. Data yang diperoleh kemudian dianalisis mengunakan paired sampel T test antara titer antibodi hog cholera. Hasil paired sample T test menunjukkan terjadinya penurunan titer antibodi maternal yang nyata (p<0,05 pada pra vaksinasi ( umur 7 hari dengan satu minggu pasca vaksinasi dan sangat nyata (p<0,01 dengan hari dua minggu pasca vaksinasi. Dari hasil penelitian ini dapat disimpulkan bahwa antibodi maternal yang tinggi akan mengakibatkan penurunan pada titer antibodi pasca vaksinasi. Perlu dilakukan penelitian lebih lanjut untuk mengetahui waktu vaksinasi yang efektif

  19. In situ measured elimination of Vibrio cholerae from brackish water.

    Science.gov (United States)

    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.

  20. [Cholera in children. A report of 8 cases].

    Science.gov (United States)

    Lezama-Basulto, L A; Mota-Hernández, F; Bravo-Barrios, E

    1993-11-01

    Cholera is an acute intestinal infection caused by Vibrio cholerae 01. When an infected person presents severe dehydration and is not adequately treated, he or she will develop hypovolemic shock and eventually could died. There is scarce information concerning this disease in the Pediatric group. Herein we report on eight cases of Pediatric cholera, in children 17 month to four years of age. Seven patients out of eight were admitted presenting dehydration. Four presenting mild or moderate dehydration and three presenting hypovolemic shock. These three patients were rehydrated by intravenous route and thereafter the hydration was maintained by oral therapy. The outcome was uneventful in six patients. One patient developed abdominal distention probably due to hypopotassemia, and another patient presented hyponatremia and seizures. All the patients recovered within five days after admission.

  1. Distance decay of tree species similarity in protected areas on terra firme forests in Colombian Amazonia

    NARCIS (Netherlands)

    Duque, Á.; Phillips, J.F.; von Hildebrand, P.; Posada, C.A.; Prieto, A.; Rudas, A.; Suescún, M.; Stevenson, P.

    2009-01-01

    In this study, we investigated the pattern of floristic similarity as a function of geographical distances and environmental variability in well-drained uplands (terra firme) in Colombian Amazonia. The study site comprised three National Natural Parks, Tinigua, Chiribiquete, and Amacayacu, located

  2. ECOLOGICAL RESEARCH IN THE LARGE-SCALE BIOSPHERE–ATMOSPHERE EXPERIMENT IN AMAZONIA: EARLY RESULTS.

    Science.gov (United States)

    M. Keller; A. Alencar; G. P. Asner; B. Braswell; M. Bustamente; E. Davidson; T. Feldpausch; E. Fern ndes; M. Goulden; P. Kabat; B. Kruijt; F. Luizao; S. Miller; D. Markewitz; A. D. Nobre; C. A. Nobre; N. Priante Filho; H. Rocha; P. Silva Dias; C von Randow; G. L. Vourlitis

    2004-01-01

    The Large-scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, and the prospect for sustainable land use in the Amazon region. Early...

  3. Ecological research in the large-scale biosphere-atmosphere experiment in Amazonia: early results

    NARCIS (Netherlands)

    Keller, M.; Alencar, A.; Asner, G.P.; Braswell, B.; Bustamante, M.; Davidson, E.; Feldpausch, T.; Fernandes, E.; Goulden, M.; Kabat, P.; Kruijt, B.; Luizão, F.; Miller, S.; Markewitz, D.; Nobre, A.D.; Nobre, C.A.; Priante Filho, N.; Rocha, da H.; Silva Dias, P.; Randow, von C.; Vourlitis, G.L.

    2004-01-01

    The Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage,. nutrient dynamics, trace gas fluxes,

  4. An illustrated key to nymphs of Perlidae (Insecta, Plecoptera genera in Central Amazonia, Brazil

    Directory of Open Access Journals (Sweden)

    Hamada Neusa

    2003-01-01

    Full Text Available An illustrated key to nymphs of Perlidae collected in streams of Central Amazonia, Brazil is provided. Three genera are reported for this region: Macrogynoplax Enderlein, Anacroneuria Klapálek and Enderleina Jewett. Additional diagnostic characters are provided for Enderleina nymphs.

  5. Estimates of the height of the boundary layer using SODAR and rawinsoundings in Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, G [Instituto de Aeronautica e Espaco (IAE/CTA), Sao Jose dos Campos, 12228-904 (Brazil); Santos, L A R dos [Instituto Nacional de Meteorologia (INMET), BrasIlia, 70680-900 (Brazil)], E-mail: gfisch@iae.cta.br, E-mail: landre@inmet.gov.br

    2008-05-01

    During the LBA campaign in Amazonia 2002, simultaneous measurements were made of the boundary layer using different instruments (rawinsoundings and SODAR). The profiles of potential temperature and humidity were used to estimates the height of the boundary layer using 3 different techniques. The SODAR's measurements did not capture the shallow morning boundary layer observed at the profiles.

  6. The Amazonian Craton and its influence on past fluvial systems (Mesozoic-Cenozoic, Amazonia)

    NARCIS (Netherlands)

    Hoorn, C.; Roddaz, M.; Dino, R.; Soares, E.; Uba, C.; Ochoa-Lozano, D.; Mapes, R.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The Amazonian Craton is an old geological feature of Archaean/Proterozoic age that has determined the character of fluvial systems in Amazonia throughout most of its past. This situation radically changed during the Cenozoic, when uplift of the Andes reshaped the relief and drainage patterns of

  7. Amazon forest dynamics under changing abiotic conditions in the early Miocene (Colombian Amazonia)

    NARCIS (Netherlands)

    Salamanca Villegas, S.; van Soelen, E.; Teunissen van Manen, M.L.; Flantua, S.G.A.; Santos, R.V.; Roddaz, M.; Dantas, E.L.; van Loon, E.; Sinninghe Damsté, J.S.; Kim, J.-H.; Hoorn, C.

    2016-01-01

    Aim We analysed in detail a past marine incursion event in north-westernAmazonia and measured its effect on the forest composition. We also deter-mined the sediment provenance in the ?uvio-estuarine system and recon-structed the overall ?oral composition of the Amazon lowland forest duringthe

  8. Species richness and distribution of understorey bryophytes in different forest types in Colombian Amazonia

    NARCIS (Netherlands)

    Benavides, J.C.; Duque, A.J.; Duivenvoorden, J.F.; Cleef, A.M.

    2006-01-01

    The first bryophyte survey results from Colombian Amazonia are presented. Bryophyte species, differentiated into mosses and liverworts, and further into four life-form classes, were sampled in 0.1-ha plots. These plots were distributed over four landscape units in the middle Caquetá area:

  9. Amazon forest dynamics under changing abiotic conditions in the early Miocene (Colombian Amazonia)

    NARCIS (Netherlands)

    Salamanca, S.; van Soelen, E.E.; Teunissen van Manen, Milan L.; Flantua, Suzette G.A.; Ventura Santos, Roberto; Roddaz, M.; Dantas, Elton Luiz; van Loon, Emiel; Sinninghe Damsté, J.S.; Kim, J.H.; Hoorn, Carina

    2016-01-01

    Aim We analysed in detail a past marine incursion event in north-western Amazonia and measured its effect on the forest composition. We also determined the sediment provenance in the fluvio-estuarine system and reconstructed the overall floral composition of the Amazon lowland forest during the

  10. Miocene fish faunas from the northwestern Amazonia basin (Colombia, Peru, Brazil) with evidence of marine incursions

    NARCIS (Netherlands)

    Monsch, KA

    1998-01-01

    New evidence indicates marine influences during the Miocene in the northwestern Amazonia basin. This is the first major survey of the ichthyofauna from this area in the Miocene. Fossil fish remains from taxa such as the Dasyatoidea, Myliobatoidea, Characiformes, Siluriformes and Sciaenidae are

  11. Modeling fire-driven deforestation potential in Amazonia under current and projected climate conditions

    NARCIS (Netherlands)

    Le Page, Y.; van der Werf, G.R.; Morton, D.C.; Pereira, J.M.C.

    2010-01-01

    Fire is a widely used tool to prepare deforested areas for agricultural use in Amazonia. Deforestation is currently concentrated in seasonal forest types along the arc of deforestation, where dry-season conditions facilitate burning of clear-felled vegetation. Interior Amazon forests, however, are

  12. Carbon replacement and stability changes in short-term silvo-pastoralo experiments in Colombian Amazonia

    NARCIS (Netherlands)

    Mosquera Vidal, O.; Buurman, P.; Ramirez, B.L.; Amezquita, M.C.

    2012-01-01

    There is little information on the effects of land use change on soil Carbon stocks in Colombian Amazonia. Such information would be needed to assess the impact of this area on the global C cycle and the sustainability of agricultural systems that are replacing native forest. The aim of this study

  13. Peru-15 (Choleragarde(®)), a live attenuated oral cholera vaccine, is safe and immunogenic in human immunodeficiency virus (HIV)-seropositive adults in Thailand.

    Science.gov (United States)

    Ratanasuwan, W; Kim, Y H; Sah, B K; Suwanagool, S; Kim, D R; Anekthananon, A; Lopez, A L; Techasathit, W; Grahek, S L; Clemens, J D; Wierzba, T F

    2015-09-11

    Many areas with endemic and epidemic cholera report significant levels of HIV transmission. According to the World Health Organization (WHO), over 95% of reported cholera cases occur in Africa, which also accounts for nearly 70% of people living with HIV/AIDS globally. Peru-15, a promising single dose live attenuated oral cholera vaccine (LA-OCV), was previously found to be safe and immunogenic in cholera endemic areas. However, no data on the vaccine's safety among HIV-seropositive adults had been collected. This study was a double-blinded, individually randomized, placebo-controlled trial enrolling HIV-seropositive adults, 18-45 years of age, conducted in Bangkok, Thailand, to assess the safety of Peru-15 in a HIV-seropositive cohort. 32 HIV infected subjects were randomized to receive either a single oral dose of the Peru-15 vaccine with a buffer or a placebo (buffer only). No serious adverse events were reported during the follow-up period in either group. The geometric mean fold (GMF) rise in V. cholerae O1 El Tor specific antibody titers between baseline and 7 days after dosing was 32.0 (pcholerae was isolated from the stool of one vaccinee, and found to be genetically identical to the Peru-15 vaccine strain. There were no significant changes in HIV viral load or CD4 T-cell counts between vaccine and placebo groups. Peru-15 was shown to be safe and immunogenic in HIV-seropositive Thai adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004-2013: a retrospective cross-sectional study.

    Science.gov (United States)

    Torane, V; Kuyare, S; Nataraj, G; Mehta, P; Dutta, S; Sarkar, B

    2016-11-25

    Cholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types between 2004 and 2013 among Vibrio cholerae isolates. A retrospective cross-sectional study. A single-centre study was carried out at a tertiary care hospital in a metropolitan city (Mumbai) of a developing country (India). Records of stool specimen cultures of patients with suspected cholera from January 2004 to December 2013 were analysed. The organisms were identified as per standard protocol. Antimicrobial susceptibility testing was performed as per Clinical Laboratory Standard Institute. Biotyping, serotyping and phage typing were carried out. From the confirmed cases of cholera, demographic and laboratory details were noted. Descriptive analysis was used and the data were presented in the form of percentages. Vibrio cholerae was predominant in males and was isolated from 9.41% (439/4664) of stool specimens. Variability was found in terms of the gross appearance of stool specimens, seasonal trend and antibiotic resistance pattern. The antimicrobial susceptibility showed a waxing and waning pattern for most of the antibiotics (ampicillin, cefuroxime, chloramphenicol, tetracycline) tested, while for a few others the strains were either uniformly sensitive (gentamicin, norfloxacin) or resistant (trimethoprim-sulfamethoxazole, nalidixic acid). All isolates belonged to subgroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type was T2 (old scheme) and T27 (new scheme). The predominant biotype, serotype and phage type were El Tor, Ogawa and T27 phage, respectively. The changing trends in antimicrobial resistance pattern over the years necessitate continued epidemiological and microbiological surveillance of the disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a

  15. Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004–2013: a retrospective cross-sectional study

    Science.gov (United States)

    Torane, V; Kuyare, S; Nataraj, G; Mehta, P; Dutta, S; Sarkar, B

    2016-01-01

    Objectives Cholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types between 2004 and 2013 among Vibrio cholerae isolates. Design A retrospective cross-sectional study. Settings A single-centre study was carried out at a tertiary care hospital in a metropolitan city (Mumbai) of a developing country (India). Methods Records of stool specimen cultures of patients with suspected cholera from January 2004 to December 2013 were analysed. The organisms were identified as per standard protocol. Antimicrobial susceptibility testing was performed as per Clinical Laboratory Standard Institute. Biotyping, serotyping and phage typing were carried out. From the confirmed cases of cholera, demographic and laboratory details were noted. Descriptive analysis was used and the data were presented in the form of percentages. Results Vibrio cholerae was predominant in males and was isolated from 9.41% (439/4664) of stool specimens. Variability was found in terms of the gross appearance of stool specimens, seasonal trend and antibiotic resistance pattern. The antimicrobial susceptibility showed a waxing and waning pattern for most of the antibiotics (ampicillin, cefuroxime, chloramphenicol, tetracycline) tested, while for a few others the strains were either uniformly sensitive (gentamicin, norfloxacin) or resistant (trimethoprim-sulfamethoxazole, nalidixic acid). All isolates belonged to subgroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type was T2 (old scheme) and T27 (new scheme). Conclusions The predominant biotype, serotype and phage type were El Tor, Ogawa and T27 phage, respectively. The changing trends in antimicrobial resistance pattern over the years necessitate continued epidemiological and microbiological surveillance of the disease. PMID:27888174

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

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

    2009-02-01

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

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

    Science.gov (United States)

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

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  19. 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.

  20. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among urban high-risk groups: findings of a cross-sectional study in Dhaka, Bangladesh

    Science.gov (United States)

    2013-01-01

    Background In endemic countries such as Bangladesh, consequences of cholera place an enormous financial and social burden on patients and their families. Cholera vaccines not only provide health benefits to susceptible populations but also have effects on the earning capabilities and financial stability of the family. Community-based research and evaluations are necessary to understand perceptions about and practices of the community relating to cholera and oral cholera vaccines. This may help identify the ways in which such vaccines may be successfully introduced, and other preventive measures can be implemented. The present study assessed the knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among an urban population residing in a high cholera-prone setting in Dhaka, Bangladesh. Methods This cross-sectional study was conducted in an area of high cholera prevalence in 15 randomly-selected clusters in Mirpur, Dhaka city. A study team collected data through a survey and in-depth interviews during December 2010–February 2011. Results Of 2,830 families included in the final analysis, 23% could recognize cholera as acute watery diarrhea and 16% had ever heard of oral cholera vaccine. About 54% of the respondents had poor knowledge about cholera-related issues while 97% had a positive attitude toward cholera and oral cholera vaccine. One-third showed poor practice relating to the prevention of cholera. The findings showed a significant (p cholera were the significant predictors to having poor knowledge. Conclusions The findings suggest the strengthening of health education activities to improve knowledge on cholera, its prevention and treatment and information on cholera vaccination among high-risk populations. The data also underscore the potential of mass cholera vaccination to prevent and control cholera. PMID:23509860

  4. Vibrio vulnificus phage PV94 is closely related to temperate phages of V. cholerae and other Vibrio species.

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    Mark Pryshliak

    Full Text Available BACKGROUND: Vibrio vulnificus is an important pathogen which can cause serious infections in humans. Yet, there is limited knowledge on its virulence factors and the question whether temperate phages might be involved in pathogenicity, as is the case with V. cholerae. Thus far, only two phages (SSP002 and VvAW1 infecting V. vulnificus have been genetically characterized. These phages were isolated from the environment and are not related to Vibrio cholerae phages. The lack of information on temperate V. vulnificus phages prompted us to isolate those phages from lysogenic strains and to compare them with phages of other Vibrio species. RESULTS: In this study the temperate phage PV94 was isolated from a V. vulnificus biotype 1 strain by mitomycin C induction. PV94 is a myovirus whose genome is a linear double-stranded DNA of 33,828 bp with 5'-protruding ends. Sequence analysis of PV94 revealed a modular organization of the genome. The left half of the genome comprising the immunity region and genes for the integrase, terminase and replication proteins shows similarites to V. cholerae kappa phages whereas the right half containing genes for structural proteins is closely related to a prophage residing in V. furnissii NCTC 11218. CONCLUSION: We present the first genomic sequence of a temperate phage isolated from a human V. vulnificus isolate. The sequence analysis of the PV94 genome demonstrates the wide distribution of closely related prophages in various Vibrio species. Moreover, the mosaicism of the PV94 genome indicates a high degree of horizontal genetic exchange within the genus Vibrio, by which V. vulnificus might acquire virulence-associated genes from other species.

  5. Cholera Vaccination Campaign Contributes to Improved Knowledge Regarding Cholera and Improved Practice Relevant to Waterborne Disease in Rural Haiti

    Science.gov (United States)

    Aibana, Omowunmi; Franke, Molly; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C.

    2013-01-01

    Background Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. Methodology/Principal Findings We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May–June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52–2.40), preventive methods (OR 1.83; 95% CI 1.46–2.30), and water treatment modalities (OR 2.75; 95% CI 2.16–3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28–2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03–1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14–1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35–4.51). Conclusion An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti. PMID:24278498

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

    Directory of Open Access Journals (Sweden)

    Omowunmi Aibana

    2013-11-01

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

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

    Science.gov (United States)

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

    2003-06-01

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

  8. Hornborg, A. & Hill, J. D. (eds. 2011. Ethnicity in Ancient Amazonia: Reconstructing Past Identities from Archaeology, Linguistics and Ethnohistory

    Directory of Open Access Journals (Sweden)

    Phil Riris

    2013-02-01

    Full Text Available Book review: Hornborg, A. & Hill, J. D. (eds. 2011. 'Ethnicity in Ancient Amazonia:' 'Reconstructing Past Identities from Archaeology, Linguistics and Ethnohistory.' Boulder: University Press of Colorado, £60

  9. LBA-ECO LC-04 Satellite/Census-Based 5-Minute Land Use Data, Amazonia: 1980 and 1995

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains 5-minute land use maps for agricultural activity in Amazonia. The data set was produced by the statistical fusion of agricultural census data...

  10. Growth Phase, Oxygen, Temperature and Starvation Affect the Development of Viable but Non-Culturable State of Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Bin eWu

    2016-03-01

    Full Text Available AbstractVibrio cholerae can enter into a viable but non-culturable (VBNC state in order to survive in unfavourable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW. Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 106-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22°C or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 108 CFU/mL to 106–105 CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB, but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different

  11. Time Resolved Measurements of Primary Biogenic Aerosol Particles in Amazonia

    Science.gov (United States)

    Wollny, A. G.; Garland, R.; Pöschl, U.

    2009-04-01

    Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the Amazonian Aerosol Characterization Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. This presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 µm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as "viable aerosols" or "fluorescent bioparticles" (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. Data from the UVAPS were averaged over 5 minute time intervals. The presence of bioparticles in the observed size range has been

  12. Impact of Biomass Burning Aerosols on the Biosphere over Amazonia

    Science.gov (United States)

    Malavelle, F.; Haywood, J.; Mercado, L.; Folberth, G.; Bellouin, N.

    2014-12-01

    Biomass burning (BB) smoke from deforestation and the burning of agricultural waste emit a complex cocktail of aerosol particles and gases. BB emissions show a regional hotspot over South America on the edges of Amazonia. These major perturbations and impacts on surface temperature, surface fluxes, chemistry, radiation, rainfall, may have significant consequent impacts on the Amazon rainforest, the largest and most productive carbon store on the planet. There is therefore potential for very significant interaction and interplay between aerosols, clouds, radiation and the biosphere in the region. Terrestrial carbon production (i.e. photosynthesis) is intimately tied to the supply of photosynthetically active radiation (PAR - i.e. wavelengths between 300-690 nm). PAR in sufficient intensity and duration is critical for plant growth. However, if a decrease in total radiation is accompanied by an increase in the component of diffuse radiation, plant productivity may increase due to higher light use efficiency per unit of PAR and less photosynthetic saturation. This effect, sometimes referred as diffuse light fertilization effect, could have increased the global land carbon sink by approximately one quarter during the global dimming period and is expected to be a least as important locally. By directly interacting with radiation, BB aerosols significantly reduce the total amount of PAR available to plant canopies. In addition, BB aerosols also play a centre role in cloud formation because they provide the necessary cloud condensation nuclei, hence indirectly altering the water cycle and the components and quantity of PAR. In this presentation, we use the recent observations from the South American Biomass Burning Analysis (SAMBBA) to explore the impact of radiation changes on the carbon cycle in the Amazon region caused by BB emissions. A parameterisation of the impact of diffuse and direct radiation upon photosynthesis rates and net primary productivity in the

  13. Continuous soil carbon storage of old permanent pastures in Amazonia.

    Science.gov (United States)

    Stahl, Clément; Fontaine, Sébastien; Klumpp, Katja; Picon-Cochard, Catherine; Grise, Marcia Mascarenhas; Dezécache, Camille; Ponchant, Lise; Freycon, Vincent; Blanc, Lilian; Bonal, Damien; Burban, Benoit; Soussana, Jean-François; Blanfort, Vincent

    2017-08-01

    Amazonian forests continuously accumulate carbon (C) in biomass and in soil, representing a carbon sink of 0.42-0.65 GtC yr -1 . In recent decades, more than 15% of Amazonian forests have been converted into pastures, resulting in net C emissions (~200 tC ha -1 ) due to biomass burning and litter mineralization in the first years after deforestation. However, little is known about the capacity of tropical pastures to restore a C sink. Our study shows in French Amazonia that the C storage observed in native forest can be partly restored in old (≥24 year) tropical pastures managed with a low stocking rate (±1 LSU ha -1 ) and without the use of fire since their establishment. A unique combination of a large chronosequence study and eddy covariance measurements showed that pastures stored between -1.27 ± 0.37 and -5.31 ± 2.08 tC ha -1  yr -1 while the nearby native forest stored -3.31 ± 0.44 tC ha -1  yr -1 . This carbon is mainly sequestered in the humus of deep soil layers (20-100 cm), whereas no C storage was observed in the 0- to 20-cm layer. C storage in C4 tropical pasture is associated with the installation and development of C3 species, which increase either the input of N to the ecosystem or the C:N ratio of soil organic matter. Efforts to curb deforestation remain an obvious priority to preserve forest C stocks and biodiversity. However, our results show that if sustainable management is applied in tropical pastures coming from deforestation (avoiding fires and overgrazing, using a grazing rotation plan and a mixture of C3 and C4 species), they can ensure a continuous C storage, thereby adding to the current C sink of Amazonian forests. © 2016 John Wiley & Sons Ltd.

  14. Brazilian Amazonia Deforestation Detection Using Spatio-Temporal Scan Statistics

    Science.gov (United States)

    Vieira, C. A. O.; Santos, N. T.; Carneiro, A. P. S.; Balieiro, A. A. S.

    2012-07-01

    The spatio-temporal models, developed for analyses of diseases, can also be used for others fields of study, including concerns about forest and deforestation. The aim of this paper is to quantitatively check priority areas in order to combat deforestation on the Amazon forest, using the space-time scan statistic. The study area location is at the south of the Amazonas State and cover around 297.183 kilometre squares, including the municipality of Boca do Acre, Labrea, Canutama, Humaita, Manicore, Novo Aripuana e Apui County on the north region of Brazil. This area has showed a significant change for land cover, which has increased the number of deforestation's alerts. Therefore this situation becomes a concern and gets more investigation, trying to stop factors that increase the number of cases in the area. The methodology includes the location and year that deforestation's alert occurred. These deforestation's alerts are mapped by the DETER (Detection System of Deforestation in Real Time in Amazonia), which is carry out by the Brazilian Space Agency (INPE). The software SatScanTM v7.0 was used in order to define space-time permutation scan statistic for detection of deforestation cases. The outcome of this experiment shows an efficient model to detect space-time clusters of deforestation's alerts. The model was efficient to detect the location, the size, the order and characteristics about activities at the end of the experiments. Two clusters were considered actives and kept actives up to the end of the study. These clusters are located in Canutama and Lábrea County. This quantitative spatial modelling of deforestation warnings allowed: firstly, identifying actives clustering of deforestation, in which the environment government official are able to concentrate their actions; secondly, identifying historic clustering of deforestation, in which the environment government official are able to monitoring in order to avoid them to became actives again; and finally

  15. BRAZILIAN AMAZONIA DEFORESTATION DETECTION USING SPATIO-TEMPORAL SCAN STATISTICS

    Directory of Open Access Journals (Sweden)

    C. A. O. Vieira

    2012-07-01

    Full Text Available The spatio-temporal models, developed for analyses of diseases, can also be used for others fields of study, including concerns about forest and deforestation. The aim of this paper is to quantitatively check priority areas in order to combat deforestation on the Amazon forest, using the space-time scan statistic. The study area location is at the south of the Amazonas State and cover around 297.183 kilometre squares, including the municipality of Boca do Acre, Labrea, Canutama, Humaita, Manicore, Novo Aripuana e Apui County on the north region of Brazil. This area has showed a significant change for land cover, which has increased the number of deforestation's alerts. Therefore this situation becomes a concern and gets more investigation, trying to stop factors that increase the number of cases in the area. The methodology includes the location and year that deforestation’s alert occurred. These deforestation's alerts are mapped by the DETER (Detection System of Deforestation in Real Time in Amazonia, which is carry out by the Brazilian Space Agency (INPE. The software SatScanTM v7.0 was used in order to define space-time permutation scan statistic for detection of deforestation cases. The outcome of this experiment shows an efficient model to detect space-time clusters of deforestation’s alerts. The model was efficient to detect the location, the size, the order and characteristics about activities at the end of the experiments. Two clusters were considered actives and kept actives up to the end of the study. These clusters are located in Canutama and Lábrea County. This quantitative spatial modelling of deforestation warnings allowed: firstly, identifying actives clustering of deforestation, in which the environment government official are able to concentrate their actions; secondly, identifying historic clustering of deforestation, in which the environment government official are able to monitoring in order to avoid them to became

  16. Relative contributions of Vibrio polysaccharide and quorum sensing to the resistance of Vibrio cholerae to predation by heterotrophic protists.

    Directory of Open Access Journals (Sweden)

    Shuyang Sun

    Full Text Available Protozoan grazing is a major mortality factor faced by bacteria in the environment. Vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. Previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of Vibrio polysaccharide (VPS. In addition to negatively controlling vps genes, the global quorum sensing (QS regulator, HapR, plays a role in grazing resistance as the ΔhapR strain is efficiently consumed while the wild type (WT is not. Here, the relative and combined contributions of VPS and QS to grazing resistance were investigated by exposing VPS and HapR mutants and double mutants in VPS and HapR encoding genes at different phases of biofilm development to amoeboid and flagellate grazers. Data show that the WT biofilms were grazing resistant, the VPS mutants were less resistant than the WT strain, but more resistant than the QS mutant strain, and that QS contributes to grazing resistance mainly in mature biofilms. In addition, grazing effects on biofilms of mixed WT and QS mutant strains were investigated. The competitive fitness of each strain in mixed biofilms was determined by CFU and microscopy. Data show that protozoa selectively grazed the QS mutant in mixed biofilms, resulting in changes in the composition of the mixed community. A small proportion of QS mutant cells which comprised 4% of the mixed biofilm biovolume were embedded in grazing resistant WT microcolonies and shielded from predation, indicating the existence of associational protection in mixed biofilms.

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

    Directory of Open Access Journals (Sweden)

    M Boustanshenas

    2013-01-01

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

  18. Co-variations of Cholera with Climatic and Environmental ...

    African Journals Online (AJOL)

    Significant co-variations were found between seasonally adjusted cases and coastal ocean chlorophyll a and to some degree sea surface temperature, both lagged by one to four months. Cholera cases in Dar es Salaam were also weakly related to the Indian Ocean Dipole Mode Index lagged by 5 months, suggesting that it ...

  19. cholera epidemiology in zambia from 2000 to 2010: implications for ...

    African Journals Online (AJOL)

    2013-10-10

    Oct 10, 2013 ... Zambian cholera data on the global health atlas to ensure consistency [6]. ... Management Committee (NEPPC&MC) meetings were also .... The inadequate water supply situation for Lusaka ... maintaining safe water chain at the household level through ... cost and logistics for administration needs to be.

  20. Feasibility and acceptability of oral cholera vaccine mass ...

    African Journals Online (AJOL)

    ... acceptable by the community to conduct a largescale mass OCV campaign in Malawi within five weeks. Of 320,000 OCV doses received, Malawi managed to administer at least 294,221 (91.9%) of the doses. OCV could therefore be considered to be introduced as additional measure in cholera hot spot areas in Malawi.

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

    African Journals Online (AJOL)

    A study to determine the prevalence of Vibrio cholerae 01 in stool sample submitted for routine examination of enteric pathogens, as well as identify the serotypes and antibiogram of the isolates to commonly used antibiotics was undertaken. The survey involved the examination of 774 (763 stool and 11 rectal swabs) ...

  2. Endemicity of cholera in Nigeria: A mathematical model to ...

    African Journals Online (AJOL)

    The focal point is to investigate the persistent endemic nature of cholera in Nigeria using mathematical model. We found that, there can be no backward bifurcation because there existed only one positive endemic equilibrium. In other words, it is not possible for multiple endemic equilibria to exist if the reproduction number ...

  3. The case of cholera preparedness, response and prevention in the ...

    African Journals Online (AJOL)

    In this paper the authors seek to identify the most appropriate model for a regional co-ordination mechanism for cholera preparedness, response and prevention. The qualitative mixed-method data collection approach that was followed revealed the need for alternative solutions, including a socio-political understanding of ...

  4. Host-pathogen interactions: A cholera surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Aaron T.

    2016-02-22

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

  5. Factors associated to populations' behaviour towards cholera in ...

    African Journals Online (AJOL)

    A disease related to hygiene, cholera is an affection which rages for centuries in the endemic states with epidemic hatchings worldwide. Benin, in particular in its littoral region, is not spared by the disease. The objective of this study was to determine the behavioural factors of the bad hygiene practice of the populations from ...

  6. [Cholera in Mexico City during the nineteenth century].

    Science.gov (United States)

    Marquez Morfin, L

    1992-01-01

    The author draws on epidemiological and historical records for this description of the demographic impact of the fatal cholera epidemics of 1833 and 1848-1850 on the population of Mexico City, Mexico. Consideration is given to political, economic, and social factors that influenced the spread of the disease.

  7. [The cholera epidemic of 1833 and mortality in Mexico City].

    Science.gov (United States)

    Velasco, M D

    1992-01-01

    The author examines the impact of the 1833 cholera epidemic in Mexico City, Mexico, on social, economic, and political aspects of life in that city. She finds that some five percent of the population died during the epidemic, and enumerates them by age and sex.

  8. A comparison of various modelling approaches applied to Cholera ...

    African Journals Online (AJOL)

    The analyses are demonstrated on data collected from Beira, Mozambique. Dynamic regression was found to be the preferred forecasting method for this data set. Keywords:Cholera, modelling, signal processing, dynamic regression, negative binomial regression, wavelet analysis, cross-wavelet analysis. ORiON Vol.

  9. Hydroclimatic mechanisms of cholera transmission in the Bengal Delta

    Science.gov (United States)

    Tretkoff, Ernie

    2011-07-01

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

  10. Factors associated with cholera in Kenya, 2008-2013 | Cowman ...

    African Journals Online (AJOL)

    The data were analyzed using a zero-inflated negative binomial regression model. Results: Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05).

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

    Science.gov (United States)

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

    1994-01-01

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

  12. In situ measured elimination of Vibrio cholerae from brackish water

    Czech Academy of Sciences Publication Activity Database

    Martínez-P., M. E.; Macek, Miroslav; Castro-G., M. T.

    2004-01-01

    Roč. 9, č. 1 (2004), s. 133-140 ISSN 1360-2276 R&D Projects: GA MŠk(CZ) ME 296 Grant - others:UNAM/DGAPA/PAPIT(MX) IN216796 Keywords : Vibrio cholerae * protozoan feeding * brackish water Subject RIV: EE - Microbiology, Virology Impact factor: 1.969, year: 2004

  13. Dynamics of cholera epidemics with impulsive vaccination and disinfection.

    Science.gov (United States)

    Sisodiya, Omprakash Singh; Misra, O P; Dhar, Joydip

    2018-04-01

    Waterborne diseases have a tremendous influence on human life. The contaminated drinking water causes water-borne disease like cholera. Pulse vaccination is an important and effective strategy for the elimination of infectious diseases. A waterborne disease like cholera can also be controlled by using impulse technique. In this paper, we have proposed a delayed SEIRB epidemic model with impulsive vaccination and disinfection. We have studied the pulse vaccination strategy and sanitation to control the cholera disease. The existence and stability of the disease-free and endemic periodic solution are investigated both analytically and numerically. It is shown that there exists an infection-free periodic solution, using the impulsive dynamical system defined by the stroboscopic map. It is observed that the infection-free periodic solution is globally attractive when the impulse period is less than some critical value. From the analysis of the model, we have obtained a sufficient condition for the permanence of the epidemic with pulse vaccination. The main highlight of this paper is to introduce impulse technique along with latent period into the SEIRB epidemic model to investigate the role of pulse vaccination and disinfection on the dynamics of the cholera epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Salmonella and Vibrio cholerae in Nile perch ( Lates niloticus ...

    African Journals Online (AJOL)

    The Nile perch (Lates niloticus) industry in East Africa has suffered severe economic losses in the last few years due to failure to comply with the microbiological standards of European Union (E.U). Fresh and frozen products have been suspected to be contaminated with Salmonella and Vibrio cholerae. This has led to a ...

  15. Assessing effects of cholera vaccination in the presence of interference.

    Science.gov (United States)

    Perez-Heydrich, Carolina; Hudgens, Michael G; Halloran, M Elizabeth; Clemens, John D; Ali, Mohammad; Emch, Michael E

    2014-09-01

    Interference occurs when the treatment of one person affects the outcome of another. For example, in infectious diseases, whether one individual is vaccinated may affect whether another individual becomes infected or develops disease. Quantifying such indirect (or spillover) effects of vaccination could have important public health or policy implications. In this article we use recently developed inverse-probability weighted (IPW) estimators of treatment effects in the presence of interference to analyze an individually-randomized, placebo-controlled trial of cholera vaccination that targeted 121,982 individuals in Matlab, Bangladesh. Because these IPW estimators have not been employed previously, a simulation study was also conducted to assess the empirical behavior of the estimators in settings similar to the cholera vaccine trial. Simulation study results demonstrate the IPW estimators can yield unbiased estimates of the direct, indirect, total, and overall effects of vaccination when there is interference provided the untestable no unmeasured confounders assumption holds and the group-level propensity score model is correctly specified. Application of the IPW estimators to the cholera vaccine trial indicates the presence of interference. For example, the IPW estimates suggest on average 5.29 fewer cases of cholera per 1000 person-years (95% confidence interval 2.61, 7.96) will occur among unvaccinated individuals within neighborhoods with 60% vaccine coverage compared to neighborhoods with 32% coverage. Our analysis also demonstrates how not accounting for interference can render misleading conclusions about the public health utility of vaccination. © 2014, The International Biometric Society.

  16. Analyzing transmission dynamics of cholera with public health interventions.

    Science.gov (United States)

    Posny, Drew; Wang, Jin; Mukandavire, Zindoga; Modnak, Chairat

    2015-06-01

    Cholera continues to be a serious public health concern in developing countries and the global increase in the number of reported outbreaks suggests that activities to control the diseases and surveillance programs to identify or predict the occurrence of the next outbreaks are not adequate. These outbreaks have increased in frequency, severity, duration and endemicity in recent years. Mathematical models for infectious diseases play a critical role in predicting and understanding disease mechanisms, and have long provided basic insights in the possible ways to control infectious diseases. In this paper, we present a new deterministic cholera epidemiological model with three types of control measures incorporated into a cholera epidemic setting: treatment, vaccination and sanitation. Essential dynamical properties of the model with constant intervention controls which include local and global stabilities for the equilibria are carefully analyzed. Further, using optimal control techniques, we perform a study to investigate cost-effective solutions for time-dependent public health interventions in order to curb disease transmission in epidemic settings. Our results show that the basic reproductive number (R0) remains the model's epidemic threshold despite the inclusion of a package of cholera interventions. For time-dependent controls, the results suggest that these interventions closely interplay with each other, and the costs of controls directly affect the length and strength of each control in an optimal strategy. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Identification of burden hotspots and risk factors for cholera in India: An observational study.

    Science.gov (United States)

    Ali, Mohammad; Sen Gupta, Sanjukta; Arora, Nisha; Khasnobis, Pradeep; Venkatesh, Srinivas; Sur, Dipika; Nair, Gopinath B; Sack, David A; Ganguly, Nirmal K

    2017-01-01

    Even though cholera has existed for centuries and many parts of the country have sporadic, endemic and epidemic cholera, it is still an under-recognized health problem in India. A Cholera Expert Group in the country was established to gather evidence and to prepare a road map for control of cholera in India. This paper identifies cholera burden hotspots and factors associated with an increased risk of the disease. We acquired district level data on cholera case reports of 2010-2015 from the Integrated Disease Surveillance Program. Socioeconomic characteristics and coverage of water and sanitation was obtained from the 2011 census. Spatial analysis was performed to identify cholera hotspots, and a zero-inflated Poisson regression was employed to identify the factors associated with cholera and predicted case count in the district. 27,615 cholera cases were reported during the 6-year period. Twenty-four of 36 states of India reported cholera during these years, and 13 states were classified as endemic. Of 641 districts, 78 districts in 15 states were identified as "hotspots" based on the reported cases. On the other hand, 111 districts in nine states were identified as "hotspots" from model-based predicted number of cases. The risk for cholera in a district was negatively associated with the coverage of literate persons, households using treated water source and owning mobile telephone, and positively associated with the coverage of poor sanitation and drainage conditions and urbanization level in the district. The study reaffirms that cholera continues to occur throughout a large part of India and identifies the burden hotspots and risk factors. Policymakers may use the findings of the article to develop a roadmap for prevention and control of cholera in India.

  18. An Optimal Cost Effectiveness Study on Zimbabwe Cholera Seasonal Data from 2008–2011

    Science.gov (United States)

    Sardar, Tridip; Mukhopadhyay, Soumalya; Bhowmick, Amiya Ranjan; Chattopadhyay, Joydev

    2013-01-01

    Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008–09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008–09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to study such recurrent occurrences and fitted the model to cumulative cholera cases and deaths for different provinces of Zimbabwe from the beginning of cholera outbreak in 2008–09 to June 2011. Daily and weekly reported cholera incidence data were collected from Zimbabwe epidemiological bulletin, Zimbabwe Daily cholera updates and Office for the Coordination of Humanitarian Affairs Zimbabwe (OCHA, Zimbabwe). For each province, the basic reproduction number () in periodic environment is estimated. To the best of our knowledge, this is probably a pioneering attempt to estimate in periodic environment using real-life data set of cholera epidemic for Zimbabwe. Our estimates of agree with the previous estimate for some provinces but differ significantly for Bulawayo, Mashonaland West, Manicaland, Matabeleland South and Matabeleland North. Seasonal trend in cholera incidence is observed in Harare, Mashonaland West, Mashonaland East, Manicaland and Matabeleland South. Our result suggests that, slow transmission is a dominating factor for cholera transmission in most of these provinces. Our model projects cholera cases and cholera deaths during the end of the epidemic in 2008–09 to January 1, 2012. We also determine an optimal cost-effective control strategy among the four government undertaken interventions namely promoting hand-hygiene & clean water distribution, vaccination, treatment and sanitation for each province. PMID:24312540

  19. A single dose of live-attenuated 638 Vibrio cholerae oral vaccine is safe and immunogenic in adult volunteers in Mozambique

    Directory of Open Access Journals (Sweden)

    Hilda María García

    2011-12-01

    Full Text Available A placebo-controlled randomized, double-blind, clinical trial was carried out to assess the safety, reactogenicity, and immunogenicity of the lyophilized vaccine candidate against cholera derived from the live attenuated 638 Vibrio cholerae O1 El Tor Ogawa strain. One hundred and twenty presumably healthy female and male adult volunteers aged between 18 and 50 years were included. They were from Maputo, Mozambique a cholera endemic area, where, in addition, human immunodeficiency virus (HIV seroprevalence is from 20 to 30%. A dose of 2 x 10 9 colony forming units (CFU was given to 80 subjects and other 40 received only vaccine lyoprotectors as a placebo control. Out-patient follow-up of adverse events was carried out during the following 30 days after vaccination. The immune response was evaluated by the estimation of seroconversion rate and the geometric mean titer (GMT of vibriocidal antibodies in the sera from volunteers that was collected previously, and at days 14 and 21 after immunization. No serious adverse events were reported. The adverse events found in the vaccine group were similar to those of the placebo groups. They were independent from the detection of antibodies against HIV-1, HIV-2, hepatitis (H A; HC and hepatitis B surface antigen. The presence of helminthes did not modify the incidence of adverse events. The 638 vaccine strain was isolated in 37 (46.25% vaccinated volunteer's feces. The peak of the GMT of vibriocidal antibodies in the vaccine group was 9056 versus 39 in the placebo group at 14 days with a total seroconversion of 97.4% at 21 days. The 638 vaccine candidate is safe and immunogenic in a cholera endemic region.

  20. Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes.

    Science.gov (United States)

    Schaefer, C E G R; do Amaral, E F; de Mendonça, B A F; Oliveira, H; Lani, J L; Costa, L M; Fernandes Filho, E I

    2008-05-01

    The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east-west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There

  1. Cholera: tackling the epidemic in a hostile environment

    Directory of Open Access Journals (Sweden)

    Carlota GONZÁLEZ PÓZEGA

    2015-07-01

    Full Text Available The Painted Veil (2006 is a love story which takes place in the nineteen twenties, between an Englishman, Dr Walter Fane, a bacteriologist, and Kitty, an English upper class girl, who marry for convenience hardly knowing each other. Soon after the wedding they move to Shangai, where Walter is in charge of a government laboratory. Also in Shangai Kitty meets Charles, a married vice consul with whom she has an affair. When Walter discovers that his wife has been unfaithful to him he threatens to divorce her if she refuses to go with him to a village in Inner China, where there is an outbreak of cholera and where his help is required. They settle on the outskirts of Mei?tan?fu. The relationship between Walter and kitty cannot go worse; they hardly talk to each other, and while Walter is working day and night, trying to stop the spread of cholera, Kitty feels lonely and useless . One day she visits a group of French nuns who collaborate in the hospital and run an orphanage, in which Kitty is finally able to help as a music teacher. The fight against cholera is arduous: customs, religion, and politics make the doctor’s work even harder. It is then that Walter and Kitty discover qualities in each other that they did not know of; finally love and reconciliation emerge. When it seems that the outbreak of cholera is already under control, people from downstream villages, where there is no doctor, arrive. Walter feels obliged to set up a refugee camp on the outskirts of the city, where he finally contracts cholera and dies.

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

    Science.gov (United States)

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

    1995-04-01

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

  3. 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.

  4. Expansion of the SOS regulon of Vibrio cholerae through extensive transcriptome analysis and experimental validation.

    Science.gov (United States)

    Krin, Evelyne; Pierlé, Sebastian Aguilar; Sismeiro, Odile; Jagla, Bernd; Dillies, Marie-Agnès; Varet, Hugo; Irazoki, Oihane; Campoy, Susana; Rouy, Zoé; Cruveiller, Stéphane; Médigue, Claudine; Coppée, Jean-Yves; Mazel, Didier

    2018-05-21

    The SOS response is an almost ubiquitous response of cells to genotoxic stresses. The full complement of genes in the SOS regulon for Vibrio species has only been addressed through bioinformatic analyses predicting LexA binding box consensus and in vitro validation. Here, we perform whole transcriptome sequencing from Vibrio cholerae treated with mitomycin C as an SOS inducer to characterize the SOS regulon and other pathways affected by this treatment. Comprehensive transcriptional profiling allowed us to define the full landscape of promoters and transcripts active in V. cholerae. We performed extensive transcription start site (TSS) mapping as well as detection/quantification of the coding and non-coding RNA (ncRNA) repertoire in strain N16961. To improve TSS detection, we developed a new technique to treat RNA extracted from cells grown in various conditions. This allowed for identification of 3078 TSSs with an average 5'UTR of 116 nucleotides, and peak distribution between 16 and 64 nucleotides; as well as 629 ncRNAs. Mitomycin C treatment induced transcription of 737 genes and 28 ncRNAs at least 2 fold, while it repressed 231 genes and 17 ncRNAs. Data analysis revealed that in addition to the core genes known to integrate the SOS regulon, several metabolic pathways were induced. This study allowed for expansion of the Vibrio SOS regulon, as twelve genes (ubiEJB, tatABC, smpA, cep, VC0091, VC1190, VC1369-1370) were found to be co-induced with their adjacent canonical SOS regulon gene(s), through transcriptional read-through. Characterization of UV and mitomycin C susceptibility for mutants of these newly identified SOS regulon genes and other highly induced genes and ncRNAs confirmed their role in DNA damage rescue and protection. We show that genotoxic stress induces a pervasive transcriptional response, affecting almost 20% of the V. cholerae genes. We also demonstrate that the SOS regulon is larger than previously known, and its syntenic organization is

  5. 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...

  6. Edaphic and light conditions of sympatric plant morphotypes in western Amazonia

    Directory of Open Access Journals (Sweden)

    Julissa Roncal

    2014-05-01

    Full Text Available Here I present a dataset of edaphic and light conditions associated with the occurrence of sympatric morphotypes of Geonoma macrostachys (Arecaceae/Palmae, a candidate case study from Amazonia hypothesized to have evolved under ecological speciation. Transects were established in three lowland rainforests in Peru, and the abundance of each local morphotype of this species was recorded in a total area of 4.95 hectares. Composite soil samples and hemispherical photographs were taken along the transects were the species occurred to obtain information on soil nutrients, soil texture, and indirect measurements of light availability. The raw and summary tables disclose the characteristics of each study site and habitats within them, which could be useful to soil scientists, ecologists, and conservationists engaged in similar research activities or meta-analyses in Amazonia.

  7. A new species of phlebotomine, Trichophoromyia adelsonsouzai (Diptera: Psychodidae of Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Thiago Vasconcelos dos Santos

    2014-04-01

    Full Text Available The phlebotomine sandfly Trichophoromyia adelsonsouzai sp. nov. is described and illustrated based on the male and female morphological characteristics of specimens collected at Km 27 of the Trans-Amazonian Highway, municipality of Vitória do Xingu, state of Pará, Brazilian Amazonia. This is an area subject to the direct influence of Belo Monte hydroelectric system. With the description of this new species the number of Trichophoromyia sandflies recorded in Brazil is increased to 20.

  8. The Roles and Movements of Actors in the Deforestation of Brazilian Amazonia

    OpenAIRE

    Philip M. Fearnside

    2008-01-01

    Containing the advance of deforestation in Brazilian Amazonia requires understanding the roles and movements of the actors involved. The importance of different actors varies widely among locations within the region, and also evolves at any particular site over the course of frontier establishment and consolidation. Landless migrants have significant roles in clearing the land they occupy and in motivating landholders to clear as a defense against invasion or expropriation. Colonists in offic...

  9. IKONOS imagery for the Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA).

    Science.gov (United States)

    George Hurtt; Xiangming Xiao; Michael Keller; Michael Palace; Gregory P. Asner; Rob Braswell; Brond& #305; Eduardo S. zio; Manoel Cardoso; Claudio J.R. Carvalho; Matthew G. Fearon; Liane Guild; Steve Hagen; Scott Hetrick; Berrien Moore III; Carlos Nobre; Jane M. Read; S& aacute; Tatiana NO-VALUE; Annette Schloss; George Vourlitis; Albertus J. Wickel

    2003-01-01

    The LBA-ECO program is one of several international research components under the Brazilian-led Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA). The field-oriented research activities of this study are organized along transects and include a set of primary field sites, where the major objective is to study land-use change and ecosystem dynamics, and a...

  10. Molecular composition of organic aerosols in central Amazonia: an ultra-high-resolution mass spectrometry study

    OpenAIRE

    Kourtchev, I; Godoi, RHM; Connors, S; Levine, JG; Archibald, AT; Godoi, AFL; Paralovo, SL; Barbosa, CGG; Souza, RAF; Manzi, AO; Seco, R; Sjostedt, S; Park, J-H; Guenther, A; Kim, S

    2016-01-01

    The Amazon Basin plays key role in atmospheric chemistry, biodiversity and climate change. In this study we applied nanoelectrospray (nanoESI) ultra-high-resolution mass spectrometry (UHRMS) for the analysis of the organic fraction of PM$_{2.5}$ aerosol samples collected during dry and wet seasons at a site in central Amazonia receiving background air masses, biomass burning and urban pollution. Comprehensive mass spectral data evaluation methods (e.g. Kendrick mass defect, Van Krevelen diagr...

  11. Bryophyte diversity patterns in flooded and tierra firme forests in the Araracuara Region, Colombian Amazonia

    OpenAIRE

    Benavides, Juan C.; Idarraga, Alvaro; Alvarez, Esteban

    2004-01-01

    We investigated patterns of bryophyte species richness and composition in two forest types of Colombian Amazonia, non-flooded tierra firme forest and floodplain forest of the Caquetá River. A total of 109 bryophyte species were recorded from 14 0.2 ha plots. Bryophyte life forms and habitats were analyzed, including the canopy and epiphylls. Bryophyte species did not show significant differences between landscapes but mosses and liverworts were different and with opposite responses balancing ...

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

    KAUST Repository

    Abd El Ghany, Moataz; Chander, Jagadish; Mutreja, Ankur; Rashid, Mamoon; Hill-Cawthorne, Grant A.; Ali, Shahjahan; Naeem, Raeece; Thomson, Nicholas R.; Dougan, Gordon; Pain, Arnab

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Moataz Abd El Ghany

    2014-07-01

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

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

    Science.gov (United States)

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

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distribu