WorldWideScience

Sample records for live hog cholera

  1. 9 CFR 311.3 - Hog cholera.

    Science.gov (United States)

    2010-01-01

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

  2. 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

  3. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Science.gov (United States)

    2010-01-01

    ... responsibility for the control of swine diseases in the State where the swine are located. (b) All swine, even... 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...

  4. Development and evaluation of an enzyme-labeled antibody test for the rapid detection of hog cholera antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, G.C.

    1977-01-01

    A rapid enzyme-labeled antibody (ELA) microtechnique for the screening of swine for hog cholera antibodies was developed and evaluated with a blind study, using a 640-sample hog cholera serum bank. The total time to run a group of 22 samples was approximately 1 hour. The ELA test results correlated >99% with hog cholera serum-neutralization test results on the same serums. Test results also indicated that the ELA test shares with the hog cholera serum-neutralization test the problem of cross reactions between the antibodies of hog cholera and bovine viral diarrhea.

  5. Human depredation by vampire bats (Desmodus rotundus) following a hog cholera campaign.

    Science.gov (United States)

    McCarthy, T J

    1989-03-01

    Hog cholera control efforts in Belize in 1975 included the slaughter of village pigs, a primary food source for the vampire bat (Desmodus rotundus). The bats then fed on secondary food sources, including humans. In 1 village, 22% of the families interviewed were exposed to attacks: 17 children and 2 adults were bit. Human depredation was not continuous as Desmodus located other hosts.

  6. Cholera

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  8. CHOLERA

    African Journals Online (AJOL)

    a cholera-like disease in the United Arab Republic, Ethio- pia, Malawi, Senegal, Sudan ... spread dissemination and sharp outbreaks of cholera. This is particularly so in ... Given early and adequate treatment cholera is no longer a higWy lethal ...

  9. Cholera.

    OpenAIRE

    Kaper, J B; Morris, J G; Levine, M M

    1995-01-01

    Despite more than a century of study, cholera still presents challenges and surprises to us. Throughout most of the 20th century, cholera was caused by Vibrio cholerae of the O1 serogroup and the disease was largely confined to Asia and Africa. However, the last decade of the 20th century has witnessed two major developments in the history of this disease. In 1991, a massive outbreak of cholera started in South America, the one continent previously untouched by cholera in this century. In 199...

  10. Cholera.

    Science.gov (United States)

    Kaper, J B; Morris, J G; Levine, M M

    1995-01-01

    Despite more than a century of study, cholera still presents challenges and surprises to us. Throughout most of the 20th century, cholera was caused by Vibrio cholerae of the O1 serogroup and the disease was largely confined to Asia and Africa. However, the last decade of the 20th century has witnessed two major developments in the history of this disease. In 1991, a massive outbreak of cholera started in South America, the one continent previously untouched by cholera in this century. In 1992, an apparently new pandemic caused by a previously unknown serogroup of V. cholerae (O139) began in India and Bangladesh. The O139 epidemic has been occurring in populations assumed to be largely immune to V. cholerae O1 and has rapidly spread to many countries including the United States. In this review, we discuss all aspects of cholera, including the clinical microbiology, epidemiology, pathogenesis, and clinical features of the disease. Special attention will be paid to the extraordinary advances that have been made in recent years in unravelling the molecular pathogenesis of this infection and in the development of new generations of vaccines to prevent it.

  11. Cholera.

    Science.gov (United States)

    Lippi, Donatella; Gotuzzo, Eduardo; Caini, Saverio

    2016-08-01

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

  12. PaxVax CVD 103-HgR single-dose live oral cholera vaccine.

    Science.gov (United States)

    Levine, Myron M; Chen, Wilbur H; Kaper, James B; Lock, Michael; Danzig, Lisa; Gurwith, Marc

    2017-03-01

    Cholera remains a problem in developing countries and a risk for travelers. Hypochlorhydria, blood group O, cardiac and renal disease increase the risk of developing cholera gravis. Oral vaccines containing inactivated Vibrio cholerae and requiring two doses are available in some countries. No cholera vaccine had been available for U.S. travelers for decades until 2016 when CVD 103-HgR (VAXCHORA™), an oral live attenuated vaccine, was licensed by the U.S. FDA. Areas covered: Enduring protection following wild-type cholera provided the rationale to develop a single-dose live oral vaccine. CVD 103-HgR is well-tolerated and protects against cholera caused by V. cholerae O1 of either serotype (Inaba, Ogawa) and biotype (El Tor, Classical). Since 90% vaccine efficacy is evident 10 days post-ingestion of a single dose, CVD 103-HgR can rapidly protect travelers. Vibriocidal antibody seroconversion correlates with protection; >90% of U.S. adult (including elderly) vaccinees seroconvert. The U.S. Public Health Service's Advisory Committee on Immunization Practices recommends CVD 103-HgR for U.S. travelers to areas of ongoing cholera transmission. Expert commentary: Next steps include evaluations in children, post-licensure safety and effectiveness monitoring, diminishing cold chain constraints, optimizing a 'high-dose' formulation for developing countries, and diminishing/eliminating the need for water to administer a dose.

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

    Science.gov (United States)

    Herzog, Christian

    2016-01-01

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

  14. Live oral cholera vaccine: evaluation of the clinical effectiveness of two strains in humans.

    Science.gov (United States)

    Cash, R A; Music, S I; Libonati, J P; Schwartz, A R; Hornick, R B

    1974-10-01

    El Tor Ogawa C14-S5 and EW-6, two live vaccine candidate strains, were given to volunteers in varying doses with and without bicarbonate. Vibrios were found in the stool of one of 32 men given the vaccine strain, and only three men developed a significant titer rise (fourfold or greater) at 2 weeks of vibriocidal or antitoxic antibody. Five men who had previously received 10(9) organisms of the C14-S5 strain were challenged subsequently with virulent Ogawa 395 Vibrio cholerae. The rate of clinical infection in these men was no different than in unvaccinated controls. It was demonstrated that the live oral cholera vaccines did not remain viable in the intestine long enough to act antigenically.

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

    Science.gov (United States)

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

    1997-07-01

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

  16. Vibrio cholerae biofilm growth program and architecture revealed by single-cell live imaging.

    Science.gov (United States)

    Yan, Jing; Sharo, Andrew G; Stone, Howard A; Wingreen, Ned S; Bassler, Bonnie L

    2016-09-01

    Biofilms are surface-associated bacterial communities that are crucial in nature and during infection. Despite extensive work to identify biofilm components and to discover how they are regulated, little is known about biofilm structure at the level of individual cells. Here, we use state-of-the-art microscopy techniques to enable live single-cell resolution imaging of a Vibrio cholerae biofilm as it develops from one single founder cell to a mature biofilm of 10,000 cells, and to discover the forces underpinning the architectural evolution. Mutagenesis, matrix labeling, and simulations demonstrate that surface adhesion-mediated compression causes V. cholerae biofilms to transition from a 2D branched morphology to a dense, ordered 3D cluster. We discover that directional proliferation of rod-shaped bacteria plays a dominant role in shaping the biofilm architecture in V. cholerae biofilms, and this growth pattern is controlled by a single gene, rbmA Competition analyses reveal that the dense growth mode has the advantage of providing the biofilm with superior mechanical properties. Our single-cell technology can broadly link genes to biofilm fine structure and provides a route to assessing cell-to-cell heterogeneity in response to external stimuli.

  17. Vibrio cholerae O1 strains are facultative intracellular bacteria, able to survive and multiply symbiotically inside the aquatic free-living amoeba Acanthamoeba castellanii.

    Science.gov (United States)

    Abd, Hadi; Saeed, Amir; Weintraub, Andrej; Nair, G Balakrish; Sandström, Gunnar

    2007-04-01

    Vibrio cholerae species are extracellular, waterborne, gram-negative bacteria that are overwhelmed by predators in aquatic environments. The unencapsulated serogroup V. cholerae O1 and encapsulated V. cholerae O139 cause epidemic and pandemic outbreaks of cholera. It has recently been shown that the aquatic and free-living amoeba Acanthamoeba castellanii is not a predator to V. cholerae O139; rather, V. cholerae O139 has shown an intracellular compatibility with this host. The aim of this study was to examine the ability of V. cholerae O1 classical and El Tor strains to grow and survive in A. castellanii. The interaction between A. castellanii and V. cholerae O1 strains was studied by means of amoeba cell counts and viable counts of the bacteria in the absence or presence of amoebae. The viable count of intracellularly growing bacteria was estimated by utilizing gentamicin assay. Confocal microscopy and electron microscopy were used to determine the intracellular localization of V. cholerae in A. castellanii. The results showed that V. cholerae O1 classical and El Tor strains grew and survived intracellularly in the cytoplasm of trophozoites, and that the bacteria were also found in the cysts of A. castellanii. The interaction showed a facultative intracellular behaviour of V. cholerae O1 classical and El Tor strains and a possible role of A. castellanii as an environmental host of V. cholerae species.

  18. Effect of alum on free-living and copepod-associated Vibrio cholerae O1 and O139.

    Science.gov (United States)

    Chowdhury, M A; Huq, A; Xu, B; Madeira, F J; Colwell, R R

    1997-08-01

    The effects of alum [KAl(SO4)2] on free-living and copepod-associated Vibrio cholerae O1 and O139 were investigated by using plate counts and immunofluorescence direct viable counting (DVC). Growth of alum-treated cells in 0.5/1000 Instant Ocean seawater was inhibited, i.e., no growth was obtained on Luria-Bertani (LB) agar or thiosulfate-citrate-bile salt-sucrose (TCBS) agar. However, a significant number of the inhibited cells maintained viability, as measured by DVC. In comparison, a significant number of V. cholerae organisms associated with zooplankton, most of which were crustacean copepods, were viable but nonculturable, with only a small number of cells retaining culturability on LB and TCBS agar. Both DVC and viable plate counts (CFU) were significantly greater for V. cholerae O1 and O139 associated with zooplankton than for V. cholerae in water alone, i.e., without copepods. It is concluded that alum is an effective coagulant but not an effective killing agent for V. cholerae and that association with copepods offers protection for V. cholerae O1 and O139 against alum and chlorine treatments.

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

    Science.gov (United States)

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

    1995-10-01

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

  20. Cholera outbreak in a village in south India - Timely action saved lives.

    Science.gov (United States)

    Deepthi, R; Sandeep, S R; Rajini, M; Rajeshwari, H; Shetty, Achal

    2013-02-01

    Cholera remains a public health concern in developing countries because of its high morbidity and mortality. This study was designed to assess the magnitude of and factors responsible for an outbreak in a South Indian village and to implement measures for containing and preventing the recurrence of such outbreaks. Data was obtained by surveying households in the village to identify cases and assess factors responsible for the outbreak. A sanitary survey of the water supply system was performed to identify the cause of the outbreak. Preventive measures were implemented by setting up a rapid response team to manage cases and provide safe drinking water and health education regarding the prevention of such outbreaks. A total of 73 cases were reported during the outbreak, an attack rate of 17.5%. Attack rates were similar among males and females, and the highest rates were observed among the elderly (33.3%), while the lowest rates were observed among adults (14.7%). There were no deaths reported due to cholera in the village. Most households (81%) surveyed did not use any method of water purification, 79.7% practiced open field defecation and 58.2% practiced inadequate hand washing, indicating poor sanitary practices. Cases were most commonly observed in houses which did not practice any method of water purification (p<0.001) and among people living below the poverty line (p=0.02). Despite the high attack rate, no deaths were reported, largely thanks to timely medical and preventive interventions. Copyright © 2012 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  1. The Live Attenuated Cholera Vaccine CVD 103-HgR Primes Responses to the Toxin-Coregulated Pilus Antigen TcpA in Subjects Challenged with Wild-Type Vibrio cholerae.

    Science.gov (United States)

    Mayo-Smith, Leslie M; Simon, Jakub K; Chen, Wilbur H; Haney, Douglas; Lock, Michael; Lyon, Caroline E; Calderwood, Stephen B; Kirkpatrick, Beth D; Cohen, Mitchell; Levine, Myron M; Gurwith, Marc; Harris, Jason B

    2017-01-01

    One potential advantage of live attenuated bacterial vaccines is the ability to stimulate responses to antigens which are only expressed during the course of infection. To determine whether the live attenuated cholera vaccine CVD 103-HgR (Vaxchora) results in antibody responses to the in vivo-induced toxin-coregulated pilus antigen TcpA, we measured IgA and IgG responses to Vibrio cholerae O1 El Tor TcpA in a subset of participants in a recently reported experimental challenge study. Participants were challenged with V. cholerae O1 El Tor Inaba N16961 either 10 days or 90 days after receiving the vaccine or a placebo. Neither vaccination nor experimental infection with V. cholerae alone resulted in a robust TcpA IgG or IgA response, but each did elicit a strong response to cholera toxin. However, compared to placebo recipients, vaccinees had a marked increase in IgG TcpA antibodies following the 90-day challenge, suggesting that vaccination with CVD 103-HgR resulted in priming for a subsequent response to TcpA. No such difference between vaccine and placebo recipients was observed for volunteers challenged 10 days after vaccination, indicating that this was insufficient time for vaccine-induced priming of the TcpA response. The priming of the response to TcpA and potentially other antigens expressed in vivo by attenuated V. cholerae may have relevance to the maintenance of immunity in areas where cholera is endemic.

  2. Living in the matrix: assembly and control of Vibrio cholerae biofilms

    Science.gov (United States)

    Teschler, Jennifer K.; Zamorano-Sánchez, David; Utada, Andrew S.; Warner, Christopher J. A.; Wong, Gerard C. L.; Linington, Roger G.; Yildiz, Fitnat H.

    2015-01-01

    Preface Nearly all bacteria form biofilms as a strategy for survival and persistence. Biofilms are associated with biotic and abiotic surfaces and are composed of aggregates of cells that are encased by a self-produced or acquired extracellular matrix. Vibrio cholerae has been studied as a model organism for understanding biofilm formation in environmental pathogens, as it spends much of its life cycle outside of the human host in the aquatic environment. Given the important role of biofilm formation in the V. cholerae life cycle, the molecular mechanisms underlying this process and the signals that trigger biofilm assembly or dispersal have been areas of intense investigation over the past 20 years. In this Review, we discuss V. cholerae surface attachment, various matrix components and the regulatory networks controlling biofilm formation. PMID:25895940

  3. Effect of alum on free-living and copepod-associated Vibrio cholerae O1 and O139.

    OpenAIRE

    Chowdhury, M A; Huq, A.; Xu, B.; Madeira, F J; Colwell, R R

    1997-01-01

    The effects of alum [KAl(SO4)2] on free-living and copepod-associated Vibrio cholerae O1 and O139 were investigated by using plate counts and immunofluorescence direct viable counting (DVC). Growth of alum-treated cells in 0.5/1000 Instant Ocean seawater was inhibited, i.e., no growth was obtained on Luria-Bertani (LB) agar or thiosulfate-citrate-bile salt-sucrose (TCBS) agar. However, a significant number of the inhibited cells maintained viability, as measured by DVC. In comparison, a signi...

  4. Randomized, controlled human challenge study of the safety, immunogenicity, and protective efficacy of a single dose of Peru-15, a live attenuated oral cholera vaccine.

    Science.gov (United States)

    Cohen, Mitchell B; Giannella, Ralph A; Bean, Judy; Taylor, David N; Parker, Susan; Hoeper, Amy; Wowk, Stephen; Hawkins, Jennifer; Kochi, Sims K; Schiff, Gilbert; Killeen, Kevin P

    2002-04-01

    Peru-15 is a live attenuated oral vaccine derived from a Vibrio cholerae O1 El Tor Inaba strain by a series of deletions and modifications, including deletion of the entire CT genetic element. Peru-15 is also a stable, motility-defective strain and is unable to recombine with homologous DNA. We wished to determine whether a single oral dose of Peru-15 was safe and immunogenic and whether it would provide significant protection against moderate and severe diarrhea in a randomized, double-blind, placebo-controlled human volunteer cholera challenge model. A total of 59 volunteers were randomly allocated to groups to receive either 2 x 10(8) CFU of reconstituted, lyophilized Peru-15 vaccine diluted in CeraVacx buffer or placebo (CeraVacx buffer alone). Approximately 3 months after vaccination, 36 of these volunteers were challenged with approximately 10(5) CFU of virulent V. cholerae O1 El Tor Inaba strain N16961, prepared from a standardized frozen inoculum. Among vaccinees, 98% showed at least a fourfold increase in vibriocidal antibody titers. After challenge, 5 (42%) of the 12 placebo recipients and none (0%) of the 24 vaccinees had moderate or severe diarrhea (> or = 3,000 g of diarrheal stool) (P = 0.002; protective efficacy, 100%; lower one-sided 95% confidence limit, 75%). A total of 7 (58%) of the 12 placebo recipients and 1 (4%) of the 24 vaccinees had any diarrhea (P Peru-15 is a well-tolerated and immunogenic oral cholera vaccine that affords protective efficacy against life-threatening cholera diarrhea in a human volunteer challenge model. This vaccine may therefore be a safe and effective tool to prevent cholera in travelers and is a strong candidate for further evaluation to prevent cholera in an area where cholera is endemic.

  5. 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 (pvaccine group compared to 1.6 (pvaccine 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.

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

    Science.gov (United States)

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

    1994-12-01

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

  7. Classical Swine Fever in Wild Hog: Report of its Prevalence in Northeast India.

    Science.gov (United States)

    Barman, N N; Bora, D P; Khatoon, E; Mandal, S; Rakshit, A; Rajbongshi, G; Depner, K; Chakraborty, A; Kumar, S

    2016-10-01

    Classical swine fever virus (CSFV) is the causative agent of a highly contagious disease, hog cholera in pigs. The disease is endemic in many parts of the world and vaccination is the only way to protect the animals from CSFV infection. Wild hogs belong to the species Sus Scrofa Cristatus under the family Suidae are quite susceptible to CSFV infection. The epidemiological role concerning classical swine fever (CSF) in India is largely unknown. We report here the three isolated cases of CSF in wild hogs from three National parks, namely Kaziranga National Park, Manas National Park and Jaldapara National Park, from north-east part of India. The post-mortem and histopathological findings were clearly indicative for CSFV infection. The presence of CSFV genome was demonstrated in several organs and tissues collected from hogs died due to viral infection. In addition, CSF-specific antibodies were detected in two wild hogs as well as in eighteen feral pigs from the same locations. The phylogenetic analysis of the partial E2 protein gene and 5' untranslated region of CSFV isolates from the wild hog showed identities with genotype 2.2 of the Indian isolates. Occurrence of CSF in wild hogs may pose a potent threat in the epidemiology of the virus in Northeast part of India. To the best of our knowledge, the report presented in the manuscript is the first comprehensive report on CSF in wild hogs form Northeast India. The findings reported would help us to understand the epidemiology and biology of CSFV in wild animals.

  8. Fowl cholera.

    Science.gov (United States)

    Christensen, J P; Bisgaard, M

    2000-08-01

    Pasteurella multocida subspecies multocida is the most common cause of fowl cholera, although P. multocida subspecies septica and gallicida may also cause fowl cholera-like disease to some extent. However, the virulence properties of the different subspecies for various hosts have not been elucidated. The severity and incidence of P. multocida infections may vary considerably depending on several factors associated with the host (including species and age of infected birds), the environment and the bacterial strain. No single virulence factor has been associated with the observed variation in virulence among strains. Possible virulence factors include the following: the capsule, endotoxin, outer membrane proteins, iron binding systems, heat shock proteins, neuraminidase production and antibody cleaving enzymes. No RTX toxins (repeats in toxin) appear to be produced by P. multocida, but P. multocida exotoxin (PMT) could contribute to virulence in some avian infections. The epidemiology of fowl cholera appears complex. Traditional serotyping systems are only of limited use in epidemiological studies. In recent years, molecular typing methods have been applied to avian strains of P. multocida of different origin. The results obtained using these newer methods indicate that wild birds may be a source of infection to commercial poultry. Documentation suggesting that mammals play a similar role is not as comprehensive, but the possibility cannot be excluded. Carrier birds seem to play a major role in the transmission of cholera. Surviving birds from diseased flocks appear to represent a risk, but more recent investigations indicate that carriers of P. multocida may exist within poultry flocks with no history of previous outbreaks of fowl cholera. The significance of this awaits further investigation. The site of infection for P. multocida is generally believed to be the respiratory tract. The outcome of infections may range from peracute/acute infections to chronic

  9. Safety and Immunogenicity of a Live Oral Recombinant Cholera Vaccine VA1.4: A Randomized, Placebo Controlled Trial in Healthy Adults in a Cholera Endemic Area in Kolkata, India

    Science.gov (United States)

    Kanungo, Suman; Sen, Bandana; Ramamurthy, Thandavarayan; Sur, Dipika; Manna, Byomkesh; Pazhani, Gururaja P.; Chowdhury, Goutam; Jhunjhunwala, Puja; Nandy, Ranjan K.; Koley, Hemanta; Bhattacharya, Mihir Kumar; Gupta, Sanjay; Goel, Gaurav; Dey, Bindu; M, Thungapathra; Nair, G. Balakrish; Ghosh, Amit; Mahalanabis, Dilip

    2014-01-01

    Background A live oral cholera vaccine VA 1.4 developed from a non-toxigenic Vibrio cholerae O1 El Tor strain using ctxB gene insertion was further developed into a clinical product following cGMP and was evaluated in a double-blind randomized placebo controlled parallel group two arm trial with allocation ratio of 1∶1 for safety and immunogenicity in men and women aged 18–60 years from Kolkata, India. Method A lyophilized dose of 1.9×109 CFU (n = 44) or a placebo (n = 43) reconstituted with a diluent was administered within 5 minutes of drinking 100 ml of a buffer solution made of sodium bicarbonate and ascorbic acid and a second dose on day 14. Result The vaccine did not elicit any diarrhea related adverse events. Other adverse events were rare, mild and similar in two groups. One subject in the vaccine group excreted the vaccine strain on the second day after first dose. The proportion of participants who seroconverted (i.e. had 4-folds or higher rise in reciprocal titre) in the vaccine group were 65.9% (95% CI: 50.1%–79.5%) at both 7 days (i.e. after 1st dose) and 21 days (i.e. after 2nd dose). None of the placebo recipients seroconverted. Anti-cholera toxin antibody was detected in very few recipients of the vaccine. Conclusion This study demonstrates that VA 1.4 at a single dose of 1.9×109 is safe and immunogenic in adults from a cholera endemic region. No additional benefit after two doses was seen. Trial Registration Clinical Trials Registry-India, National Institute of Medical Statistics (Indian Council of Medical Research) CTRI/2012/04/002582 PMID:24983989

  10. Application of the indirect enzyme-labeled antibody microtest to the detection and surveillance of animal diseases. [Brucellosis, cholera, and trichinosis in cattle and swine

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, G.C. Clinard, E.H.; Bartlett, M.L.; Sanders, W.M.

    1976-01-01

    The rapid, indirect enzyme-labeled antibody (ELA) microplate test has been developed as a diagnostic and surveillance tool to aid in the control of animal disease. Data are presented, which illustrate the application of the test to viral (hog cholera), parasitic (trichinosis), and bacterial (brucellosis) diseases of animals. A greater than 95 percent correlation was observed between the hog cholera ELA test and the hog cholera serum neutralization test performed on over 2000 mixed hog cholera positive and negative field samples obtained during the 1976 New Jersey epizootic. Of 56 swine naturally infected with Trichinella spiralis at a level considered dangerous to man, all were ELA positive, while only one of 360 T. spiralis negative packing house sera was ELA positive. Preliminary experiments with bovine brucellosis (Brucella abortus) indicate that the ELA test is more sensitive than other test methods currently in use. ELA procedures should soon become tests of choice for the detection of antibodies to animal disease agents.

  11. 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.

  12. Overview of Classical Swine Fever (Hog Cholera, Classical Swine fever)

    Science.gov (United States)

    Classical swine fever is a contagious often fatal disease of pigs clinically characterized by high body temperature, lethargy, yellowish diarrhea, vomits and purple skin discoloration of ears, lower abdomen and legs. It was first described in the early 19th century in the USA. Later, a condition i...

  13. Comparison of alternative buffers for use with a new live oral cholera vaccine, Peru-15, in outpatient volunteers.

    Science.gov (United States)

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

    1997-06-01

    During development of Peru-15, a new live oral vaccine for cholera, the role of buffer needed to be evaluated. Generally, oral bacterial vaccines are acid labile and need to be administered by using a formulation which protects them from gastric acid. We compared three different buffers for use with Peru-15, including a standard bicarbonate-ascorbic acid buffer, Alka-Seltzer, and a new electrolyte-rice buffer, CeraVacx. Saline served as the control. Thirty-nine healthy adult volunteers received Peru-15 (10(8) CFU) with one of the three buffers or saline in a double-masked study. The volunteers were monitored for symptoms for 7 days after the dose, serum was tested for antibody responses by vibriocidal antibody and immunoglobulin G antitoxin enzyme-linked immunosorbent assays, and stool samples were tested for excretion of the vaccine strain. Side effects were minimal in all groups. All 30 volunteers who took Peru-15 with a buffer showed significant rises in vibriocidal antibody titer. The magnitude of the rises was higher in the CeraVacx group than in the other two buffer groups. Four of nine volunteers who took the vaccine with saline also showed increased titers, but they were lower than those in any of the three buffer groups. Excretion of the vaccine strain was similar in the buffer groups, but excretion was not associated with the magnitude of the vibriocidal responses. Excretion of Peru-15 was not detected in the saline group. We conclude that buffer does amplify the serological response to Peru-15 and that CeraVacx may provide benefits not provided by other buffers.

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

    Science.gov (United States)

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

    2015-04-01

    Vibrio cholerae causes the human disease cholera by producing a potent toxin. The V. cholerae virulence pathway involves an unusual transcription step: the bitopic inner-membrane proteins TcpP and ToxR activate toxT transcription. As ToxT is the primary direct transcription activator in V. cholerae pathogenicity, its regulation by membrane-localized activators is key in the disease process. However, the molecular mechanisms by which membrane-localized activators engage the transcription process have yet to be uncovered in live cells. Here we report the use of super-resolution microscopy, single-molecule tracking, and gene knockouts to examine the dynamics of individual TcpP proteins in live V. cholerae cells with cholerae to that in mutant strains lacking either toxR or the toxT promoter, we determine that TcpP mobility is greater in the presence of its interaction partners than in their absence. Our findings support a mechanism in which ToxR recruits TcpP to the toxT promoter for transcription activation. © 2014 John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    Moacir Gerolomo

    2000-08-01

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

  16. A Portable Root-door Hog Trap

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Since the early 1960's, over 4,500 wild hogs have been relocated through Florida Game and Fresh Water Fish Commission trapping operations. The trap now used by the...

  17. Drinking cholera

    DEFF Research Database (Denmark)

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

    2015-01-01

    Objectives: To measure the salinity levels of common water sources in coastal Bangladesh andexplore perceptions of water palatability among the local population to investigate the plausibility oflinking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water...... beconducive to V. cholerae survival. Furthermore, salinity levels of participant’s drinking water sourceswere all well below the levels required for optimal survival of V. cholerae. Respondents explainedthat they preferred less salty and more aesthetically pleasing drinking water. Conclusion: Theoretically, V....... 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...

  18. RESEARCH AND IMPLEMENTATION OF A HOGGING ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Wang Weijun; Shen Bing; Wang Xiaochun

    2005-01-01

    Cast blanks with large-scale free form surfaces are very difficult to manufacture because of significant casting distortions. It is concerned that the development and application of a hogging algorithm for preparing the blanks for an extended rough cutting. The procedure includes three main phases. They are the reconstruction of the free form surface with scattered points based on a special Hermite's interpolation,intersection of curved surfaces to define the hogging areas, and the tool path planning. The result shows that the algorithm is greatly valid in reducing the invalid tool paths so that the work efficiency can be improved remarkably.

  19. 9 CFR 319.144 - Whole hog sausage.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Whole hog sausage. 319.144 Section 319... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Sausage Generally: Fresh Sausage § 319.144 Whole hog sausage. “Whole Hog Sausage” is sausage prepared with fresh and/or frozen meat from swine...

  20. Evaluation of a bivalent (CVD 103-HgR/CVD 111) live oral cholera vaccine in adult volunteers from the United States and Peru.

    Science.gov (United States)

    Taylor, D N; Tacket, C O; Losonsky, G; Castro, O; Gutierrez, J; Meza, R; Nataro, J P; Kaper, J B; Wasserman, S S; Edelman, R; Levine, M M; Cryz, S J

    1997-09-01

    To provide optimum protection against classical and El Tor biotypes of Vibrio cholerae O1, a single-dose, oral cholera vaccine was developed by combining two live, attenuated vaccine strains, CVD 103-HgR (classical, Inaba) and CVD 111 (El Tor, Ogawa). The vaccines were formulated in a double-chamber sachet; one chamber contained lyophilized bacteria, and the other contained buffer. In the first study, 23 U.S. adult volunteers received CVD 103-HgR at 10(8) CFU plus CVD 111 at 10(8), 10(7), or 10(6) CFU, CVD 111 alone at 10(7) CFU, or placebo. In the second study, 275 Peruvian adults were randomized to receive CVD 103-HgR at 10(9) CFU plus CVD 111 at 10(9) or 10(8) CFU, CVD 111 alone at 10(9) CFU, CVD 103-HgR alone at 10(9) CFU, or placebo. Three of 15 U.S. volunteers who received CVD 111 at 10(7) or 10(8) CFU developed mild diarrhea, compared to none of 4 who received CVD 111 at 10(6) CFU and 1 of 4 who received placebo. Twelve (63%) of 19 vaccine recipients shed the El Tor vaccine strain. All but one volunteer developed significant Ogawa and Inaba vibriocidal antibody titers. Volunteers who received CVD 111 at 10(7) CFU had geometric mean Ogawa titers four to five times higher than those of volunteers who received the lower dose. In the second study, all dosage regimens were well tolerated in Peruvians. About 20% of volunteers who received CVD 111 at the high dose excreted the El Tor organism, compared to 7% in the low-dose group. CVD 111 was detected in the stools of two placebo recipients, neither of whom had symptoms or seroconverted. In all vaccine groups, 69 to 76% developed fourfold rises in Inaba vibriocidal antibodies. Among those who received the bivalent vaccine, 53 to 75% also developed significant rises in Ogawa vibriocidal antibodies. We conclude that it is feasible to produce a single-dose, oral bivalent vaccine that is safe and immunogenic against both biotypes (El Tor and classical) and both serotypes (Inaba and Ogawa) of cholera for populations in

  1. Safety and immunogenicity of escalating dosages of a single oral administration of peru-15 pCTB, a candidate live, attenuated vaccine against enterotoxigenic Escherichia coli and Vibrio cholerae.

    Science.gov (United States)

    Chen, Wilbur H; Garza, Jose; Choquette, Monique; Hawkins, Jennifer; Hoeper, Amy; Bernstein, David I; Cohen, Mitchell B

    2015-01-01

    Enterotoxigenic Escherichia coli (ETEC) organisms are a leading cause of infectious diarrhea in developing countries. A live, attenuated cholera strain that expresses high levels of the nontoxic B subunit of cholera toxin, which might also serve as an ETEC protective antigen, was evaluated for safety, excretion, and immunogenicity in healthy volunteers. We enrolled four inpatient dose-escalation cohorts of 15 to 16 eligible subjects to randomly (3:1) receive a single oral dose of vaccine or placebo (buffer alone), evaluating 1 ×10(7), 1 ×10(8), 1 ×10(9), and 1 ×10(10) CFU of the vaccine. The vaccine was well tolerated, although some subjects experienced moderate diarrhea. The serum Inaba vibriocidal antibody response appeared to display a dose-response relationship with increasing dosages of vaccine, plateauing at the 10(9)-CFU dosage. The serum antitoxin (cholera toxin and heat-labile enterotoxin) antibody seroconversion rate (4-fold increase over baseline) also appeared to display a dose-response relationship. The vaccine strain was excreted in stool cultures, displaying a dose-response relationship. A single oral dose of Peru-15 pCTB at dosages up to 1 ×10(10) CFU was safe and immunogenic in this first-in-human trial. These encouraging data support the ongoing clinical development of this candidate combined cholera and ETEC vaccine. (This study has been registered at ClinicalTrials.gov under registration no. NCT00654108.).

  2. Age-Dependent Association among Helicobacter pylori Infection, Serum Pepsinogen Levels and Immune Response of Children to Live Oral Cholera Vaccine CVD 103-HgR

    Science.gov (United States)

    Muhsen, Khitam; Lagos, Rosanna; Reymann, Mardi K.; Graham, David Y.; Pasetti, Marcela F.; Levine, Myron M.

    2014-01-01

    Background Through its effects on gastric secretion, we hypothesized that Helicobacter pylori infection may influence oral immunization. Accordingly, we examined the association between H. pylori infection, serum pepsinogen (PG) (measures for H. pylori gastritis) and vibriocidal antibody (a correlate of protection) seroconversion following oral immunization with CVD 103-HgR live cholera vaccine among children of different ages. Methods Sera from 422 Chilean children who were vaccinated with a single dose of CVD 103-HgR were tested by ELISA for serum IgG antibodies to H. pylori, PG I and PG II levels and antibodies to Shigella flexneri 2a lipopolysaccharide and hepatitis A virus (as markers of low socioeconomic status and exposure to enteric pathogens). Results The likelihood of vibriocidal antibody seroconversion following vaccination with CVD 103-HgR was significantly decreased in H. pylori-seropositive children age 6 months to 4 years with PG II>8 µg/L (adjusted OR 0.14 (95% CI 0.03–0.61; P = 0.009), and also in H. pylori seropositives with lower PG II level (adjusted OR 0.34, 95% CI 0.14–0.83; P = 0.017), compared to H. pylori-seronegatives. H. pylori-seropositive children aged 5–9 years with serum PG I>30 µg/L (indicating more severe gastritis) had higher odds of vibriocidal seroconversion than those with lower PG I levels (adjusted OR 4.41, 95%CI 1.26–15.38; P = 0.02). There was no significant association between exposures to S. flexneri 2a or hepatitis A virus and vibriocidal seroconversion. Conclusions As H. pylori gastritis progresses with increasing pediatric age in developing country venues, changes in gastric secretion ensue that we believe explain the observed differences in age-related immune responses to immunization with live oral cholera vaccine. The effect of H. pylori and changes of gastric acid secretion on the immunogenicity of various oral vaccines should be studied in different developing, transitional and industrialized

  3. Cholera Treatment

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2010-10-01

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

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

    Science.gov (United States)

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

    1980-02-01

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

  6. Randomized, double-blind, placebo-controlled trial to evaluate the safety and immunogenicity of live oral cholera vaccine 638 in Cuban adults.

    Science.gov (United States)

    Valera, Rodrigo; García, Hilda María; Jidy, Manuel Díaz; Mirabal, Mayelin; Armesto, Marlene Isabel; Fando, Rafael; García, Luis; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Ramírez, Margarita; Bravo, Laura; Serrano, Teresita; Palma, Sara; González, Daniel; Miralles, Fernando; Medina, Vilma; Nuñez, Felicita; Plasencia, Yilian; Martínez, Juan Carlos; Mandarioti, Aleyda; Lugones, Juan; Rodríguez, Boris Luis; Moreno, Arlenis; González, Domingo; Baro, Morelia; Solis, Rosa Lidia; Sierra, Gustavo; Barbera, Ramón; Domínguez, Francisco; Gutiérrez, Carlos; Kouri, Gustavo; Campa, Concepción; Menéndez, Jorge

    2009-11-01

    A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the safety, reactogenicity and the immunogenicity of a 2 x 10(9)CFU dose of the 638 lyophilized live attenuated cholera vaccine for oral administration, formulated and produced at Finlay Institute, City of Havana, Cuba. Thirty-six healthy female and male adult volunteers from 18 to 40 years old were involved, clinically examined and laboratory tested after the informed consent signature. Adverse events were monitored and seroconversion rates and geometrical mean titer (GMT) of vibriocidal antibodies were tested in volunteer's sera samples. Neither serious adverse events nor other damages to the volunteers due to vaccine or placebo feeding were reported during the clinical follow-up period of this study; none of the adverse events registered within the first 72 h after inoculation were life-threatening for volunteers. Neither severe nor moderate adverse events were reported. Sixty-one percent of subjects showed mild expected adverse events in an interval lower than 24h up to the first 72 h, 75% of these in the vaccinated group and 18% in the placebo group. Fourteen days after inoculation the GMT of vibriocidal antibodies in the vaccine group significantly increased in comparison to the placebo group. All subjects in the vaccine group (24) seroconverted (100%). Results show that this vaccine is safe, well tolerated and immunogenic in healthy female and male volunteers.

  7. What is cholera?

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  8. Investigating nonlinear speculation in cattle, corn, and hog futures markets using logistic smooth transition regression models

    OpenAIRE

    Röthig, Andreas; Chiarella, Carl

    2006-01-01

    This article explores nonlinearities in the response of speculators' trading activity to price changes in live cattle, corn, and lean hog futures markets. Analyzing weekly data from March 4, 1997 to December 27, 2005, we reject linearity in all of these markets. Using smooth transition regression models, we find a similar structure of nonlinearities with regard to the number of different regimes, the choice of the transition variable, and the value at which the transition occurs.

  9. 基于HOG-SVD特征的人脸识别%Face Recognition Based on HOG-SVD Features

    Institute of Scientific and Technical Information of China (English)

    全雪峰

    2016-01-01

    为提高复杂环境下的人脸识别率,该文提出了一种基于方向梯度直方图-奇异值分解(HOG-SVD)的人脸识别方法。首先提取整个人脸图像的 HOG 特征,通过奇异值分解形成图像的整体 HOG-SVD 特征。然后将人脸图像分成均匀子块,提取各子块的 HOG-SVD特征。之后将整体HOG-SVD特征和局部HOG-SVD特征组合形成最终分类特征。最后通过支持向量机分类器对其分类。在Yale人脸库上的实验表明,该方法对表情、光照、姿态具有鲁棒性,具有较高的识别率。%In order to improve the rate of face recognition in complex environments, this paper proposes a face recognition method based on histogram of oriented gradient and singular value decomposition(HOG-SVD). Firstly, the HOG features are extracted on the whole face image, and the global HOG-SVD features are formed through singular value decomposition. Then the face image is divided into homogeneous sub-blocks, and the HOG-SVD features of each sub block are extracted. The global HOG-SVD and local HOG-SVD features are combined to form the final classifica-tion features. Finally, the support vector machine is employed to classify the final features. Experimental results on Yale face database demonstrate that the proposed approach not only has high recognition rate but also has certain robustness to expression, light, and pose.

  10. Price transmission in hog and feed markets of China

    Institute of Scientific and Technical Information of China (English)

    ZHOU De; Dieter Koemle

    2015-01-01

    There is an increasing demand for feed as the industrialization of hog production in China. Land scarcity limits China’s ability to continue increasing its hog production without feed imports, particularly soybean, and the feed markets are increasingly integrated into the global market. This study performs an analysis of price transmission between the hog price in China and feed prices, speciifcal y domestic maize price and international soybean price, from January 2000 to April 2014. We identiifed a long-term stable equilibrium relationship between the three markets. However, further analyses show that there is no signiifcant Granger causality between hog and feed market, and the long-run equilibrium partial y results from Granger causality between the international soybean market and domestic maize market. This suggests that the domestic hog market has been distorted by different policies. The results also indicate that the efifciency of price transmission is very low and it takes about 11 months to correct one-half of any long-run disequilibrium for the hog market in China. Therefore, to stabilize hog price in China, only market intervention to regulate the maize and soybean markets would be insufifcient and comprehensive measures need to be taken into account such as hog production modernization, agricultural insurance, epidemic surveil ance etc.

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

    Directory of Open Access Journals (Sweden)

    Saeed Amir

    2011-04-01

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

  12. A cost-benefit analysis of programmatic use of CVD 103-HgR live oral cholera vaccine in a high-risk population.

    Science.gov (United States)

    Cookson, S T; Stamboulian, D; Demonte, J; Quero, L; Martinez de Arquiza, C; Aleman, A; Lepetic, A; Levine, M M

    1997-02-01

    Cholera spread to Latin America in 1991; subsequently, cholera vaccination was considered as an interim intervention until long-term solutions involving improved water supplies and sanitation could be introduced. Three successive summer cholera outbreaks in northern Argentina and the licensing of the new single-dose oral cholera vaccine, CVD 103-HgR, raised questions of the cost and benefit of using this new vaccine. This study explored the potential benefits to the Argentine Ministry of Health of treatment costs averted, versus the costs of vaccination with CVD 103-HgR in the relatively confined population of northern Argentina affected by the cholera outbreaks. Water supplies and sanitation in this area are poor but a credible infrastructure for vaccine delivery exists. In our cost-benefit model of a 3-year period (1992-1994) with an annual incidence of 2.5 case-patients per 1000 population and assumptions of vaccine efficacy of 75% and coverage of 75%, vaccination of targeted high risk groups would prevent 1265 cases. Assuming a cost of US$602 per treated case and of US$1.50 per dose of vaccine, the total discounted savings from use of vaccine in the targeted groups would be US$132,100. The projected savings would be altered less by vaccine coverage (range 75-90%) or efficacy (60-85%) changes than by disease incidence changes. Our analysis underestimated the true costs of cholera in Argentina because we included only medical expenditures; Indirect losses to trade and tourism had the greatest economic impact. However, vaccination with CVD 103-HgR was still cost-beneficial in the base case.

  13. Cholera Prevention and Control

    Science.gov (United States)

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

  14. What is cholera?

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  15. A robust HOG-based descriptor for pattern recognition

    Science.gov (United States)

    Diaz-Escobar, Julia; Kober, Vitaly

    2016-09-01

    The Histogram of Oriented Gradients (HOG) is a popular feature descriptor used in computer vision and image processing. The technique counts occurrences of gradient orientation in localized portions of an image. The descriptor is sensible to the presence in images of noise, nonuniform illumination, and low contrast. In this work, we propose a robust HOG-based descriptor using the local energy model and phase congruency approach. Computer simulation results are presented for recognition of objects in images affected by additive noise, nonuniform illumination, and geometric distortions using the proposed and conventional HOG descriptors.

  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 Dynamic

  17. Cholera in Zimbabwe

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

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

  18. Cholera in Zimbabwe

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

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

  19. Economic Dynamics of the German Hog-Price Cycle

    Directory of Open Access Journals (Sweden)

    Ernst Berg

    2015-06-01

    Full Text Available We investigated the economic dynamics of the German hog-price cycle with an innovative ‘diagnostic’ modeling approach. Hog-price cycles are conventionally modeled stochastically—most recently as randomly-shifting sinusoidal oscillations. Alternatively, we applied Nonlinear Time Series analysis to empirically reconstruct a deterministic, low-dimensional, and nonlinear attractor from observed hog prices. We next formulated a structural (explanatory model of the pork industry to synthesize the empirical hog-price attractor. Model simulations demonstrate that low price-elasticity of demand contributes to aperiodic price cycling – a well know result – and further reveal two other important driving factors: investment irreversibility (caused by high specificity of technology, and liquidity-driven investment behavior of German farmers.

  20. Food Habits of St. Vincent Island Sambars and Hogs

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sambar deer Cervus unicolor and feral hogs Sus scrofs coninhabit St. Vincent Island, Florida. Rumen samples were analyzed to assess the dietary overlap of the two...

  1. Hog and Pig Houses, Published in Not Provided, US Army.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Hog and Pig Houses dataset as of Not Provided. Data by this publisher are often provided in Not Applicable coordinate system; in a Not Applicable projection;...

  2. Cholera epidemic threatens Sierra Leone.

    Science.gov (United States)

    Dyer, O

    1995-07-08

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

  3. Cholera: something old, something new.

    Science.gov (United States)

    Sigman, Michael; Luchette, Fred A

    2012-08-01

    In the aftermath of a devastating earthquake in early 2011, Haiti fell victim to an outbreak of cholera that claimed thousands of lives and affected populations in nearby Dominican Republic, Venezuela, and even the United States. This was the first time cholera had been reported in Haiti in more than 100 years. The sudden appearance of cholera, a pathogen with no known non-human host, raised the question of how it was introduced to an island that has long been spared this disease. The purpose of this review is to provide an overview of the history of cholera, its pathophysiology and virulence factors, and current recommendations for treatment. Articles published in the past 10 years were identified by a search of the medical literature using PUBMED and reviewed. Bibliographies of each article also were reviewed for additional pertinent articles. The recent epidemic was caused by a strain that has been responsible for disease in South Asia since 1961, the seventh and most recent strain identified since 1900. It is transmitted by the fecal-oral route. Once infected, the patient develops a rapidly dehydrating diarrheal illness caused by the cholera toxin, which activates cytoplasmic adenylate cyclase of the intestinal epithelial cells by adenosine diphosphate (ADP)-ribosylation of the stimulatory G protein. The high cyclic adenosine monophosphate (cAMP) concentrations activate the cystic fibrosis transmembrane conductance regulator, causing a dramatic efflux of ions and water from infected enterocytes and leading to watery diarrhea. The first line of therapy is oral hydration with intravenous fluids; antibiotics are reserved for patients with severe dehydration. Spread of cholera is preventable with simple modifications of hygiene and water preparation. Cholera has re-emerged as a major infectious disease in the recent past, with a global increase in its incidence. Vaccination should be considered as an adjunct for controlling the epidemics and also for volunteer

  4. Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

    Science.gov (United States)

    Oldfield, Callie A; Evans, Jonathan P

    2016-04-01

    Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long-term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12-year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long-term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world.

  5. 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...

  6. Vibrio cholerae Biofilms and Cholera Pathogenesis

    Science.gov (United States)

    Silva, Anisia J.; Benitez, Jorge A.

    2016-01-01

    Vibrio cholerae can switch between motile and biofilm lifestyles. The last decades have been marked by a remarkable increase in our knowledge of the structure, regulation, and function of biofilms formed under laboratory conditions. Evidence has grown suggesting that V. cholerae can form biofilm-like aggregates during infection that could play a critical role in pathogenesis and disease transmission. However, the structure and regulation of biofilms formed during infection, as well as their role in intestinal colonization and virulence, remains poorly understood. Here, we review (i) the evidence for biofilm formation during infection, (ii) the coordinate regulation of biofilm and virulence gene expression, and (iii) the host signals that favor V. cholerae transitions between alternative lifestyles during intestinal colonization, and (iv) we discuss a model for the role of V. cholerae biofilms in pathogenicity. PMID:26845681

  7. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Anisia J Silva

    2016-02-01

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

  8. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    Science.gov (United States)

    Silva, Anisia J; Benitez, Jorge A

    2016-02-01

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

  9. Modeling cholera outbreaks.

    Science.gov (United States)

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

    2014-01-01

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

  10. Modeling cholera outbreaks

    OpenAIRE

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

    2014-01-01

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

  11. Modeling cholera outbreaks

    Science.gov (United States)

    Longini, Ira M.; Morris, J. Glenn

    2014-01-01

    Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating models and the need to tailor models for different outbreak scenarios. PMID:23412687

  12. Modeling cholera outbreaks

    OpenAIRE

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

    2014-01-01

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

  13. Oral vaccines for preventing cholera.

    Science.gov (United States)

    Sinclair, David; Abba, Katharine; Zaman, K; Qadri, Firdausi; Graves, Patricia M

    2011-03-16

    based on data from older trials is unlikely to last beyond three years.The safety data available on killed whole cell vaccines have not demonstrated any clinically significant increase in adverse events compared to placebo.Only one live attenuated vaccine has reached Phase III clinical evaluation and was not effective (one trial, 67508 participants). Two new candidate live attenuated vaccines have demonstrated clinical effectiveness in small artificial challenge studies, but are still in development. The currently available oral killed whole cell vaccines can prevent 50 to 60% of cholera episodes during the first two years after the primary vaccination schedule. The impact and cost-effectiveness of adopting oral cholera vaccines into the routine vaccination schedule of endemic countries will depend on the prevalence of cholera, the frequency of epidemics, and access to basic services providing rapid rehydration therapy.

  14. Cholera outbreaks in India.

    Science.gov (United States)

    Ramamurthy, Thandavarayan; Sharma, Naresh C

    2014-01-01

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

  15. 9 CFR 311.22 - Hogs affected with urticaria, tinea tonsurans, demodex follicurlorum, or erythema.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hogs affected with urticaria, tinea... OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.22 Hogs affected with urticaria, tinea tonsurans, demodex follicurlorum, or erythema. Carcasses of hogs affected with urticaria (nettle rash), tinea tonsurans,...

  16. Classical swine fever (hog cholera): review of aspects relevant to control.

    Science.gov (United States)

    Penrith, M-L; Vosloo, W; Mather, C

    2011-06-01

    Classical swine fever (CSF) has the ability to spread over large distances when human intervention such as illegal swill feeding facilitates its movement. This was apparent during 2005 when CSF appeared in South Africa (SA) after an absence of 87 years. In this review, various newly published developments in terms of the diagnosis of the disease and vaccination are described and applied to situations similar to SA. The role of wildlife such as feral pigs and European wild boar in the dissemination and maintenance of CSF virus are discussed, and the dearth of knowledge on the potential of other wild pig species prevalent on southern Africa noted. The modes of spread and control measures to prevent introduction as well as during outbreaks are discussed. © 2011 Blackwell Verlag GmbH.

  17. EPIDEMIOLOGY OF CHOLERA OUTBREAK IN KAMPALA ...

    African Journals Online (AJOL)

    hi-tech

    Between December 1997 and March 1998, 6228 cases of cholera were reported, of which 1091. (17.5%) were ... The extension of the epidemic of cholera that has been observed in .... cholera vaccines in the prevention and control of cholera.

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

    Science.gov (United States)

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

    2012-08-01

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

  19. ADVANCED HETEROGENEOUS REBURN FUEL FROM COAL AND HOG MANURE

    Energy Technology Data Exchange (ETDEWEB)

    Melanie D. Jensen; Ronald C. Timpe; Jason D. Laumb

    2003-09-01

    This study was performed to investigate whether the nitrogen content inherent in hog manure and alkali used as a catalyst during processing could be combined with coal to produce a reburn fuel that would result in advanced reburning NO{sub x} control without the addition of either alkali or ammonia/urea. Fresh hog manure was processed in a cold-charge, 1-gal, batch autoclave system at 275 C under a reducing atmosphere in the presence of an alkali catalyst. Instead of the expected organic liquid, the resulting product was a waxy solid material. The waxy nature of the material made size reduction and feeding difficult as the material agglomerated and tended to melt, plugging the feeder. The material was eventually broken up and sized manually and a water-cooled feeder was designed and fabricated. Two reburn tests were performed in a pilot-scale combustor. The first test evaluated a reburn fuel mixture comprising lignite and air-dried, raw hog manure. The second test evaluated a reburn fuel mixture made of lignite and the processed hog manure. Neither reburn fuel reduced NO{sub x} levels in the combustor flue gas. Increased slagging and ash deposition were observed during both reburn tests. The material-handling and ash-fouling issues encountered during this study indicate that the use of waste-based reburn fuels could pose practical difficulties in implementation on a larger scale.

  20. 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

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Sandström, Gunnar; Saeed, Amir; Abd, Hadi

    2010-09-01

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

  4. Cholera in Azov area

    OpenAIRE

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

    2015-01-01

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

  5. 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.

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

    Science.gov (United States)

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

    2013-01-01

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

  7. Cholera Fact Sheet

    Science.gov (United States)

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

  8. Cholera outbreaks in Africa.

    Science.gov (United States)

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

    2014-01-01

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

  9. Regional cholera response discussion

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2009-09-30

    Full Text Available research questions identified by the CSIR on cholera as a trans- or cross-border communicable disease that requires complex interventions in terms of preparedness and response, management, prevention and mitigation. The workshop commenced with a...

  10. 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

  11. Spatial and demographic patterns of Cholera in Ashanti region - Ghana

    Directory of Open Access Journals (Sweden)

    Duker Alfred A

    2008-08-01

    Full Text Available Abstract Background Cholera has claimed many lives throughout history and it continues to be a global threat, especially in countries in Africa. The disease is listed as one of three internationally quarantinable diseases by the World Health organization, along with plague and yellow fever. Between 1999 and 2005, Africa alone accounted for about 90% of over 1 million reported cholera cases worldwide. In Ghana, there have been over 27000 reported cases since 1999. In one of the affected regions in Ghana, Ashanti region, massive outbreaks and high incidences of cholera have predominated in urban and overcrowded communities. Results A GIS based spatial analysis and statistical analysis, carried out to determine clustering of cholera, showed that high cholera rates are clustered around Kumasi Metropolis (the central part of the region, with Moran's Index = 0.271 and P Chi square for trend analysis reflected a direct spatial relationship between cholera and urbanization (χ2 = 2995.5, P χ2 = 1757.2, P χ2 = 831.38, P Conclusion The results suggest that high urbanization, high overcrowding, and neighborhood with Kumasi Metropolis are the most important predictors of cholera in Ashanti region.

  12. Inapparent infections and cholera dynamics.

    Science.gov (United States)

    King, Aaron A; Ionides, Edward L; Pascual, Mercedes; Bouma, Menno J

    2008-08-14

    In many infectious diseases, an unknown fraction of infections produce symptoms mild enough to go unrecorded, a fact that can seriously compromise the interpretation of epidemiological records. This is true for cholera, a pandemic bacterial disease, where estimates of the ratio of asymptomatic to symptomatic infections have ranged from 3 to 100 (refs 1-5). In the absence of direct evidence, understanding of fundamental aspects of cholera transmission, immunology and control has been based on assumptions about this ratio and about the immunological consequences of inapparent infections. Here we show that a model incorporating high asymptomatic ratio and rapidly waning immunity, with infection both from human and environmental sources, explains 50 yr of mortality data from 26 districts of Bengal, the pathogen's endemic home. We find that the asymptomatic ratio in cholera is far higher than had been previously supposed and that the immunity derived from mild infections wanes much more rapidly than earlier analyses have indicated. We find, too, that the environmental reservoir (free-living pathogen) is directly responsible for relatively few infections but that it may be critical to the disease's endemicity. Our results demonstrate that inapparent infections can hold the key to interpreting the patterns of disease outbreaks. New statistical methods, which allow rigorous maximum likelihood inference based on dynamical models incorporating multiple sources and outcomes of infection, seasonality, process noise, hidden variables and measurement error, make it possible to test more precise hypotheses and obtain unexpected results. Our experience suggests that the confrontation of time-series data with mechanistic models is likely to revise our understanding of the ecology of many infectious diseases.

  13. 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.

  14. Assessing landowners' attitudes toward wild hogs and support for control options.

    Science.gov (United States)

    Caplenor, Carlotta A; Poudyal, Neelam C; Muller, Lisa I; Yoest, Chuck

    2017-10-01

    Wild hogs (Sus scrofa) are an invasive species with destructive habits, particularly rooting and wallowing, which can directly impact agricultural crops, pasture land, and water quality. Considering wild hogs are widely dispersed across the landscape, they are extremely difficult to control. Disagreements can arise among different stakeholders over whether and how their populations should be managed. The purpose of this article was to examine Tennessee, United States landowners' attitudes toward wild hogs, to compare acceptability of control methods, and to evaluate factors significantly influencing public support for regulations to control wild hogs. Logistic regression was employed to analyze data collected from a statewide survey of rural landowners in the fall of 2015. Landowners had overwhelmingly negative attitudes towards wild hogs, and were concerned about their impact on the natural environment and rural economy. Although landowners showed support for controlling wild hogs, levels of acceptability for management options varied. Respondents favored active management and supported education and incentive-based control programs to control wild hogs. Cognitive concepts such as social and personal norms and awareness of consequences, as well as demographic characteristics, significantly predicted landowners' support for state regulations to control wild hogs in Tennessee. Findings increase our understanding of the human dimensions of wild hog management and that of other similarly invasive animals, and may guide resource managers in designing effective and socially acceptable management strategies to control wild hog populations in Tennessee and elsewhere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

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

    Science.gov (United States)

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

    2015-03-20

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

  17. Cholera cases cluster in time and space in Matlab, Bangladesh: implications for targeted preventive interventions.

    Science.gov (United States)

    Debes, Amanda K; Ali, Mohammad; Azman, Andrew S; Yunus, Mohammad; Sack, David A

    2016-12-01

    : Cholera remains a serious public health threat in Asia, Africa and in parts of the Americas. Three World health Organization (WHO) pre-qualified oral cholera vaccines are now available but their supply is limited, so current supplies must be administered strategically. This requires an improved understanding of disease transmission and control strategies. : We used demographics and disease surveillance data collected from 1991 to 2000 in Matlab, Bangladesh, to estimate the spatial and temporal extent of the zone of increased risk around cholera cases. Specifically, we compare the cholera incidence among individuals living close to cholera cases with that among individuals living close to those without medically-attended cholera in this rural endemic setting. : Those living within 50 m of a confirmed cholera case had 36 times (95% confidence interval: 23-56) the risk of becoming a cholera case in the first 3 days (after case presentation) compared with risk elsewhere in the community. The relative risk gradually declined in space and time, but remained significantly high up to 450 me away within 3 days of case presentation, and up to 150 m away within 23 days from the date of presentation of the case. : These findings suggest that, if conducted rapidly, vaccinating individuals living close to a case (ring vaccination) could be an efficient and effective strategy to target vaccine to a high-risk population in an endemic setting.

  18. Are there national risk factors for epidemic cholera? The correlation between socioeconomic and demographic indices and cholera incidence in Latin America.

    Science.gov (United States)

    Ackers, M L; Quick, R E; Drasbek, C J; Hutwagner, L; Tauxe, R V

    1998-04-01

    From 1991 through 1995, all Latin American countries maintained cholera surveillance systems to track the epidemic that entered the region through Peru in January 1991. These data were used to assess correlations between socioeconomic and demographic indices that might serve as national risk predictors for epidemic cholera in Latin America. Correlations between country-specific cumulative cholera incidence rates from 1991 through 1995 and infant mortality, the Human Development Index [HDI] a numerical value based on life expectancy, education, and income), gross national product (GNP) per capita, and female literacy were tested using the Pearson correlation coefficient. A total of 1,339,834 cholera cases with a cumulative incidence rate of 183 per 100,000 population were reported from affected Western Hemisphere countries from 1991 through 1995. Infant mortality rates were the most strongly correlated with cumulative cholera incidence based on the Pearson correlation coefficient. The HDI had a less strong negative correlation with cumulative cholera incidence. The GNP per capita and female literacy rates were weakly and negatively correlated with cholera cumulative incidence rates. Infant mortality and possibly the HDI may be useful indirect indices of the risk of sustained transmission of cholera within a Latin American country. Cumulative cholera incidence is decreased particularly in countries with infant mortality below 40 per 1000 live births. The lack of reported cholera cases in Uruguay and the Caribbean may reflect a low risk for ongoing transmission, consistent with socioeconomic and demographic indices. Cholera surveillance remains an important instrument for determining cholera trends within individual countries and regions.

  19. Intensive hog farming operations and self-reported health among nearby rural residents in Ottawa, Canada

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    Challacombe Laurel

    2009-09-01

    Full Text Available Abstract Background In 2004, hog farming operations were introduced in the village of Sarsfield in the eastern part of Ottawa, Canada. This study evaluates the health-related quality of life (HRQOL, and the prevalence of respiratory conditions among adults and children who lived in proximity to this farm. Methods A cross-sectional survey was administered to a random sample of residents from seven rural communities in the eastern part of Ottawa, Canada. We analyzed self-reported questionnaire data obtained from 723 adults and 285 children/adolescents. HRQOL was assessed using the SF-36 survey instrument, while data were also collected for sociodemographic characteristics, the prevalence of selected health conditions, and lifestyle related behaviours (e.g., smoking of participants. Variations in self-reported health according to the residential distance to the hog farm were evaluated using logistic regression and analysis of variance methods. Results For the most part, the prevalence of selected health conditions among adults and children was not associated with how far they lived from the farm. No associations were observed with migraines, respiratory conditions (asthma, rhinitis, sinusitis, and chronic bronchitis, and allergies. However, a higher prevalence of depression was noted among those who lived within 3 km of the farm relative to those who lived more than 9 km away (odds ratio = 2.01, 95% CI = 1.11, 3.65. Furthermore, individuals who lived closer to the IHF were more likely to worry about environmental issues such as water quality, outdoor and indoor smells, and air pollution. This level of worry also contributed to lower HRQOL scores for individuals who lived closer to the farm. It was also observed that the prevalence of depression was much higher among those who indicated a concern about environmental issues (18.2% when compared to those who did not (8.0%. Conclusion While our findings suggest that living in close proximity to an IHF

  20. Evaluation of Cholera Toxin Expression in Different Populations of Vibrio cholera

    OpenAIRE

    Sedigheh Ebrahimi Kasgari; Mahnaz Nourani; Yousef Yahyapour; Seyed Ehsanollah Mousavi; Enayatollah Kalantar; Hami Kaboosi (PhD); Seyed Mahmoud Amin Marashi

    2015-01-01

    Background: Cholera is one of the most diseases of human. Cholera toxin is the most important pathogenic factor in humans that causes diarrhea. The cholera toxin is produced by V. cholerae and CTXфPhage. Objectives: In this study, we have investigated the production cholera toxin with different density of Vibrio cholerae. Materials and Methods: With this propose we inoculated classical strain O1 of Vibrio cholerae ATCC 14035 and Vibrio cholerae O1biovar El Tor N16961 into th...

  1. 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

  2. The global burden of cholera.

    Science.gov (United States)

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

    2012-03-01

    To estimate the global burden of cholera using population-based incidence data and reports. 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. 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. 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.

  3. Sanitation in the time of cholera.

    Science.gov (United States)

    Misch, A

    1991-01-01

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

  4. [Biological characteristics of an Hog1 MAPK homologous gene FoHog1 knock-out mutant of Fusarium oxysporum f. sp. cubense].

    Science.gov (United States)

    Mao, Chao; Chen, Pingya; Dai, Qingdong; Yang, Laying; Huang, Junsheng

    2014-11-04

    This study was aimed to obtain a mitogen-activated protein kinase (MAPK) gene namely FoHog1 from Fusarium oxysporum f. sp. cubense and to verify its function. We amplified FoHog1 gene by PCR and RT-PCR methods and analyzed it through bioinformatics method. PEG-mediated protoplast transformation was used to create the deletion mutants of FoHog1 gene. We analyzed different biological characteristics between knock-out strain and wild-type strain. FoHog1 gene encoding a putative protein of 357 amino acids and its genetic relationship with different Fusarium' s protein. Compared with the wild-type strain, FoHog1 deletion mutants have loose hyphae colony, less spores production, lower dry weight of hyphae and more sensitive to temperature, pH and osmotic stress. FoHog1 deletion mutants also have reduced colonization ability compared with the wild-type strain. FoHog1 gene participated in mycelial growth, sporulation, catabolism of sodium acetate and ammonium chloride, osmotic stress response and pathogenic process with Fusarium oxysporum f. sp. cubense Race 4.

  5. [N-ACETYL-β-D-GLUCOSAMINIDASE OF VIBRIO CHOLERAE].

    Science.gov (United States)

    Duvanova, O V; Mishankin, B N; Vodopianov, A S; Sorokin, V M

    2016-01-01

    Study N-acetyl-β-D-glucosaminidase (chitobiase) (EC 3.2.1.30) in strains of Vibrio cholerae of O1/non-O1 serogroups of various origin, that is a component of chitinolytic complex taking into account object of isolation and epidemiologic significance of strains. Cultures of V. cholerae O1/non-O1 serogroup strains were obtained from the museum of live culture of Rostov RIPC. Enzymatic activity analysis was carried out in Hitachi F-2500 fluorescent spectrophotometer using FL Solutions licensed software. NCBI databases were used during enzyme characteristics. N-acetyl-β-D-glucosaminidase in Vcholerae O1/non-O1 serogroup strains was detected, purified by column chromatography, studied and characterized by a number of physical-chemical and biological properties. Comparative computer analysis of amino acid sequence of N-acetyl-β-D-glucosaminidases of V. cholerae (VC2217 gene), Serratia marcescens etc. has allowed. to attribute the enzyme from V. cholerae to glycosyl-hydrolases (chitobiases) of family 20 and classify it according to enzyme nomenclature as EC 3.2.1.30. N-acetyl-β-D-glucosaminidase in V. cholerae of O1/non-O1 serogroups of various origin and epidemiologic significance, participating in chitin utilization was studied and characterized for the first time, and its possible role in biology of cholera causative agent was shown.

  6. The Vaccine Candidate Vibrio cholerae 638 Is Protective against Cholera in Healthy Volunteers

    Science.gov (United States)

    García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L.; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

    2005-01-01

    Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXΦ prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 109 CFU of freshly harvested 638 buffered with 1.3% NaHCO3, while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 109 CFU of ΔCTXΦ attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 × 105 CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO3. Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (109 CFU) of strain

  7. Cholera Illness and Symptoms

    Science.gov (United States)

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

  8. Neutrophils Are Essential for Containment of Vibrio cholerae to the Intestine during the Proinflammatory Phase of Infection

    OpenAIRE

    Queen, Jessica; Satchell, Karla J Fullner

    2012-01-01

    Cholera is classically considered a noninflammatory diarrheal disease, in comparison to invasive enteric organisms, although there is a low-level proinflammatory response during early infection with Vibrio cholerae and a strong proinflammatory reaction to live attenuated vaccine strains. Using an adult mouse intestinal infection model, this study examines the contribution of neutrophils to host defense to infection. Nontoxigenic El Tor O1 V. cholerae infection is characterized by the upregula...

  9. Role of CgHOG1 in Stress Responses and Glycerol Overproduction of Candida glycerinogenes.

    Science.gov (United States)

    Ji, Hao; Zhuge, Bin; Zong, Hong; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

    2016-12-01

    Candida glycerinogenes, the glycerol producer with excellent multi-stress tolerances, is considered to be a potential biotechnological host used in the production of glycerol and its derivatives under extreme fermentation conditions. In this study, to evaluate the multiple roles of mitogen-activated protein kinase CgHOG1, we constructed a gene disruption system in the diploid C. glycerinogenes to obtain CgHOG1 null mutant. Pseudohyphae generation of the CgHOG1 mutant under non-inducing condition indicated a repressor role in morphological transitions. Disruption of CgHOG1 resulted in increased sensitivities to osmotic, acetic acid, and oxidative stress but not involved in thermotolerance. In the CgHOG1 mutant, NaCl shock failed to stimulate the accumulation of intracellular glycerol and was fatal. In addition, the CgHOG1 mutant displayed a significant prolonged growth lag phase in YPD medium with no decrease in glycerol production, whereas the mutant cannot grow under hyperosmotic condition with no detectable glycerol in broth. These results suggested that CgHOG1 plays important roles in morphogenesis and multi-stress tolerance. The growth and glycerol overproduction under osmotic stress are heavily dependent on CgHOG1 kinase.

  10. Feeding the Hog Industry in North Carolina: Agri-Industrial Restructuring in Hog Farming and Its Implications for the US Periphery

    OpenAIRE

    Donnie Charleston

    2004-01-01

    Hog farms bring with them employment to remote areas but they also bring environmental problems. What determines the location of the large-scale factory farm? It is race? Is it capital availability? The answer seems to be capital availablity

  11. Technical efifciency and its determinants in China’s hog production

    Institute of Scientific and Technical Information of China (English)

    TIAN Xu; SUN Fei-fei; ZHOU Ying-heng

    2015-01-01

    China’s hog production is undergoing a great transformation due to the soaring demand and changing raising system. Re-garding the essential role of pork in Chinese diet, a systematic analysis on the productivity and efifciency of hog production can provide signiifcant implications for policy makers. This paper investigates the productivity and efifciency of hog pro-duction and the determinants of technical efifciency in China using a household level panel data (2004–2010). A stochastic frontier translog production function with scaling property in inefifciency term is adopted for hog production analysis, and the determinants of technical efifciency are incorporated in a one-step estimation using maximum likelihood estimation. Our results show that the average technical efifciency of hog production in China is 0.5914. More importantly, we ifnd that specialized farmers have higher technical efifciency than others, and technical efifciency in the eastern region is higher than that in Central and West China.

  12. Production costs and animal welfare for four stylized hog production systems.

    Science.gov (United States)

    Seibert, Lacey; Norwood, F Bailey

    2011-01-01

    Nonhuman animal welfare is arguably the most contentious issue facing the hog industry. Animal advocacy groups influence the regulation of hog farms and induce some consumers to demand more humane pork products. Hog producers are understandably reluctant to improve animal well being unless the premium they extract exceeds the corresponding increase in cost. To better understand the relationship between animal welfare and production costs under different farm systems, this study investigates 4 stylized hog production systems. The results show that increasing animal welfare for all hogs in the United States will increase retail pork prices by a maximum of 2% for a small welfare increase and 5% for a large welfare increase. The cost of banning gestation crates measured by this study is lower than the consumer willingness-to-pay from other studies.

  13. Cholera: a great global concern.

    Science.gov (United States)

    Mandal, Shyamapada; Mandal, Manisha Deb; Pal, Nishith Kumar

    2011-07-01

    Cholera, caused by the infection of toxigenic Vibrio cholerae (V. cholerae) to humans, is a life threatening diarrheal disease with epidemic and pandemic potential. The V. cholerae, both O1 and O139 serogroups, produce a potent enterotoxin (cholera toxin) responsible for the lethal symptoms of the disease. The O1 serogroup has two biotypes (phenotypes), classical and El Tor; each of which has two major serotypes (based on antigenic responses), Ogawa and Inaba and the extremely rare Hikojima. V. cholerae O1 strains interconvert and switch between the Ogawa and Inaba serotypes. Fluid and electrolyte replacement is the mainstay of treatment of cholera patients; the severe cases require antibiotic treatment to reduce the duration of illness and replacement of fluid intake. The antibiotic therapy currently has faced difficulties due to the rapid emergence and spread of multidrug resistant V. cholerae causing several outbreaks in the globe. Currently, cholera has been becoming endemic in an increasing number of geographical areas, reflecting a failure in implementation of control measures. However, the current safe oral vaccines lower the number of resistant infections and could thus represent an effective intervention measure to control antibiotic resistance in cholera. Overall, the priorities for cholera control remain public health interventions through improved drinking water, sanitation, surveillance and access to health care facilities, and further development of safe, effective and appropriate vaccines. Thus, this review describes the facts and phenomena related to the disease cholera, which is still a great threat mainly to the developing countries, and hence a grave global concern too. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  14. 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

  15. [Cholera++ epidemic in Kenya].

    Science.gov (United States)

    Paugam, H

    1999-03-01

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

  16. Prevention of losses for hog farmers in China: insurance, on-farm biosecurity practices, and vaccination.

    Science.gov (United States)

    Zhang, Yue-hua; Li, Chu-Shiu; Liu, Chwen-Chi; Chen, Kevin Z

    2013-10-01

    Using agricultural household survey data and claim records from insurers in China, this paper analyzes hog producers' choice of the ways to prevent possible losses and identifies the relationships among biosecurity practices, vaccination, and hog insurance. By combining one probit and two structural equations, we adopt three-stage estimations by a mixed-process model to obtain results. The findings indicate that biosecurity practices provide the basic infrastructure for operating pig farms and complement both the usage of quality vaccines and the uptake of hog insurance. In addition, there is a strong substitution relationship between the quality of vaccine and the demand for hog insurance. Hog farmers that implement better biosecurity practices are more likely to seek high-quality vaccines or buy into hog insurance schemes, but not both. For those households with hog insurance, better biosecurity status, better management practices, and higher-quality vaccines significantly help to reduce loss ratios. However, we also find a moral hazard effect in that higher premium expenditures by the insured households might induce larger loss ratios.

  17. Comparison of airborne bacterial communities from a hog farm and spray field.

    Science.gov (United States)

    Arfken, Ann M; Song, Bongkeun; Sung, Jung-Suk

    2015-05-01

    Airborne bacteria from hog farms may have detrimental impacts on human health, particularly in terms of antibiotic resistance and pathogen zoonosis. Despite human health risks, very little is known about the composition and diversity of airborne bacteria from hog farms and hog-related spray fields. We used pyrosequencing analysis of 16S rRNA genes to compare airborne bacterial communities in a North Carolina hog farm and lagoon spray field. In addition, we isolated and identified antibiotic-resistant bacteria from both air samples. Based on 16S rRNA gene pyrosequence analysis, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla in airborne bacterial communities from both hog farm and spray field sites. Within the Firmicutes genera, Clostridium spp. were more abundant in the hog farm, whereas Staphylococcus spp. were higher in the spray field. The presence of opportunitic pathogens, including several Staphylococcus species and Propionibacterium acnes, was detected in both bioaerosol communities based on phylogenetic analysis. The isolation and identification of antibiotic-resistant bacteria from air samples also showed similar results with dominance of Actinobacteria and Proteobacteria in both hog farm and spray field air. Thus, the existence of opportunistic pathogens and antibiotic resistant bacteria in airborne communities evidences potential health risks to farmers and other residents from swine bioaerosol exposure.

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

    Science.gov (United States)

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

    2013-07-01

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

  19. PiHOG1, a stress regulator MAP kinase from the root endophyte fungus Piriformospora indica, confers salinity stress tolerance in rice plants

    OpenAIRE

    Abhimanyu Jogawat; Jyothilakshmi Vadassery; Nidhi Verma; Ralf Oelmüller; Meenakshi Dua; Eviatar Nevo; Atul Kumar Johri

    2016-01-01

    In this study, yeast HOG1 homologue from the root endophyte Piriformospora indica (PiHOG1) was isolated and functionally characterized. Functional expression of PiHOG1 in S. cerevisiae ∆hog1 mutant restored osmotolerance under high osmotic stress. Knockdown (KD) transformants of PiHOG1 generated by RNA interference in P. indica showed that genes for the HOG pathway, osmoresponse and salinity tolerance were less stimulated in KD-PiHOG1 compared to the wild-type under salinity stress. Furthermo...

  20. 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.

  1. Vulnerability to coastal cholera ecology.

    Science.gov (United States)

    Collins, Andrew E

    2003-10-01

    The battle to completely control cholera continues. Multiple strains, high levels of morbidity in some regions of the world, and a complex of influences on its distribution in people and the environment are accompanied by only rough resolution prediction of outbreaks. Uncertainty as to the most effective array of interventions for one of the most researched infectious diseases thwarts further progress in providing cost-effective solutions. Progress on the research front consistently points towards the importance of disease ecology, coastal environments, and the sea. However, evaluation of the link between cholera in people and environment can only be effective with analysis of human vulnerability to variable coastal cholera ecologies. As there are some clear links between the organism, cholera incidence and the sea, it is appropriate that cholera research should examine the nature of coastal population vulnerability to the disease. The paper reviews the cholera risks of human-environment interactions in coastal areas as one component of the evaluation of cholera management. This points to effective intervention through integrative knowledge of changing human and environmental ecologies, requiring improved detection, but also an acceptance of complex causality. The challenge is to identify indicators and interventions for case specific ecologies in variable locales of human vulnerability and disease hazard. Further work will therefore aim to explore improved surveillance and intervention across the socio-behavioural and ecological spectrum. Furthermore, the story of cholera continues to inform us about how we should more effectively view emergent and resurgent infectious disease hazards more generally.

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

    Directory of Open Access Journals (Sweden)

    Antarpreet Jutla

    Full Text Available Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008.Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began.Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

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

    Science.gov (United States)

    Jutla, Antarpreet; Aldaach, Haidar; Billian, Hannah; Akanda, Ali; Huq, Anwar; Colwell, Rita

    2015-01-01

    Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008. Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began. Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

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

    Science.gov (United States)

    Jutla, Antarpreet; Aldaach, Haidar; Billian, Hannah; Akanda, Ali; Huq, Anwar; Colwell, Rita

    2015-01-01

    Introduction Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008. Principal Findings Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began. Discussion Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives. PMID:26417994

  5. Human detection using HOG-HSC feature and PLS

    Institute of Scientific and Technical Information of China (English)

    HU Bin; ZHAO Chunxia; YUAN Xia; SUN Ling

    2012-01-01

    By combining histogram of oriented gradient and histograms of shearlet coefficients, which analyzes images at multiple scales and orientations based on shearlet transforms, as the feature set, we proposed a novel haman detection feature. We employ partial least squares analysis, an efficient dimensionality reduction technique, to project the feature onto a much lower dimensional subspace. We test it in INRIA person dataset by using a linear SVM, and it yields an error rate of 1.38% with a false negatives (FN) rate of 0.40% and a false positive (FP) rate of 0.98%, while the error rate of HOG is 7.11%, with a FN rate of 4.09% and a FP rate of 3.02%.

  6. Intelligent Pedestrian Detection using Optical Flow and HOG

    Directory of Open Access Journals (Sweden)

    Huma Ramzan

    2016-09-01

    Full Text Available Pedestrian detection is an important aspect of autonomous vehicle driving as recognizing pedestrians helps in reducing accidents between the vehicles and the pedestrians. In literature, feature based approaches have been mostly used for pedestrian detection. Features from different body portions are extracted and analyzed for interpreting the presence or absence of a person in a particular region in front of car. But these approaches alone are not enough to differentiate humans from non-humans in dynamic environments, where background is continuously changing. We present an automated pedestrian detection system by finding pedestrians’ motion patterns and combing them with HOG features. The proposed scheme achieved 17.7% and 14.22% average miss rate on ETHZ and Caltech datasets, respectively.

  7. Epidemic cholera spreads like wildfire

    Science.gov (United States)

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

    2014-01-01

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

  8. 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

  9. 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 Cholera toxin is the aetiological agent of cholera – a deadly waterborne disease acquired through the consumption of untreated water contaminated with CTX bacteriophage harbouring strains of V. cholerae. Solar disinfection is a re...

  10. Role of Ectoine in Vibrio cholerae Osmoadaptation

    OpenAIRE

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

    2003-01-01

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

  11. Fish as Hosts of Vibrio cholerae

    OpenAIRE

    Halpern, Malka; Izhaki, Ido

    2017-01-01

    Vibrio cholerae, the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae. So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. choler...

  12. Hyperinfectivity: a critical element in the ability of V. cholerae to cause epidemics?

    Directory of Open Access Journals (Sweden)

    David M Hartley

    2006-01-01

    Full Text Available Cholera is an ancient disease that continues to cause epidemic and pandemic disease despite ongoing efforts to limit its spread. Mathematical models provide one means of assessing the utility of various proposed interventions. However, cholera models that have been developed to date have had limitations, suggesting that there are basic elements of cholera transmission that we still do not understand.Recent laboratory findings suggest that passage of Vibrio cholerae O1 Inaba El Tor through the gastrointestinal tract results in a short-lived, hyperinfectious state of the organism that decays in a matter of hours into a state of lower infectiousness. Incorporation of this hyperinfectious state into our disease model provides a much better fit with the observed epidemic pattern of cholera. These findings help to substantiate the clinical relevance of laboratory observations regarding the hyperinfectious state, and underscore the critical importance of human-to-human versus environment-to-human transmission in the generation of epidemic and pandemic disease.To have maximal impact on limiting epidemic spread of cholera, interventions should be targeted toward minimizing risk of transmission of the short-lived, hyperinfectious form of toxigenic Vibrio cholerae. The possibility of comparable hyperinfectious states in other major epidemic diseases also needs to be evaluated and, as appropriate, incorporated into models of disease prevention.

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

    African Journals Online (AJOL)

    abp

    Introduction: Cholera is a disease caused by the bacterium Vibrio cholera and has ... of cholera occurred in Kuria West District spreading to the neighboring Migori District. .... Cholera treatment centres were not set up and cases were referred.

  14. Hunting Plan: Amendment to conduct Becoming an Outdoors Woman Feral Hog Hunt

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is the hog hunt plan for the Becoming an Outdoors Woman (BOW) program on St. Vincent NWR. The objective of the BOW hunt is to provide a quality hunting...

  15. Back Bay National Wildlife Refuge Deer and Hog Hunt Program 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Refuge hunting for the 1998 season included white-tailed deer and feral hogs only. The State of Virginia's Department of Game & Inland Fisheries (VDGIF)...

  16. Study of the Ubiquitous Hog Farm System Using Wireless Sensor Networks for Environmental Monitoring and Facilities Control

    Directory of Open Access Journals (Sweden)

    Jeonghwan Hwang

    2010-12-01

    Full Text Available Many hog farmers are now suffering from high pig mortality rates due to various wasting diseases and increased breeding costs, etc. It is therefore necessary for hog farms to implement systematic and scientific pig production technology to increase productivity and produce high quality pork in order to solve these problems. In this study, we describe such a technology by suggesting a ubiquitous hog farm system which applies WSN (Wireless Sensor Network technology to the pig industry. We suggest that a WSN and CCTV (Closed-circuit television should be installed on hog farms to collect environmental and image information which shall then help producers not only in monitoring the hog farm via the Web from outside the farm, but also facilitate the control of hog farm facilities in remote locations. In addition, facilities can be automatically controlled based on breeding environment parameters which are already set up and a SMS notice service to notify of deviations shall provide users with convenience. Hog farmers may increase production and improve pork quality through this ubiquitous hog farm system and prepare a database with information collected from environmental factors and the hog farm control devices, which is expected to provide information needed to design and implement suitable control strategies for hog farm operation.

  17. Members of the human gut microbiota involved in recovery from Vibrio cholerae infection

    Science.gov (United States)

    Hsiao, Ansel; Shamsir Ahmed, A.M.; Subramanian, Sathish; Griffin, Nicholas W.; Drewry, Lisa L.; Petri, William A.; Haque, Rashidul; Ahmed, Tahmeed; Gordon, Jeffrey I.

    2015-01-01

    Given the global burden of diarrheal diseases1, it is important to understand how members of the gut microbiota affect the risk for, course of, and recovery from disease in children and adults. The acute, voluminous diarrhea caused by Vibrio cholerae represents a dramatic example of enteropathogen invasion and gut microbial community disruption. We have conducted a detailed time-series metagenomic study of fecal microbiota collected during the acute diarrheal and recovery phases of cholera in a cohort of Bangladeshi adults living in an area with a high burden of disease2. We find that recovery is characterized by a pattern of accumulation of bacterial taxa that shows similarities to the pattern of assembly/maturation of the gut microbiota in healthy Bangladeshi children3. To define underlying mechanisms, we introduced into gnotobiotic mice an artificial community that was composed of human gut bacterial species that directly correlate with recovery from cholera in adults and are indicative of normal microbiota maturation in healthy Bangladeshi children3. One of the species, Ruminococcus obeum, exhibited consistent increases in its relative abundance upon V. cholerae infection of the mice. Follow-up analyses, including mono- and co-colonization studies, established that R. obeum restricts V. cholerae colonization, that R. obeum luxS [autoinducer-2 (AI-2) synthase] expression and AI-2 production increase significantly with V. cholerae invasion, and that R. obeum AI-2 causes quorum-sensing mediated repression of several V. cholerae colonization factors. Co-colonization with V. cholerae mutants disclosed that R. obeum AI-2 reduces Vibrio colonization/pathogenicity through a novel pathway that does not depend on the V. cholerae AI-2 sensor, LuxP. The approach described can be used to mine the gut microbiota of Bangladeshi or other populations for members that use autoinducers and/or other mechanisms to limit colonization with V. cholerae, or conceivably other

  18. Members of the human gut microbiota involved in recovery from Vibrio cholerae infection.

    Science.gov (United States)

    Hsiao, Ansel; Ahmed, A M Shamsir; Subramanian, Sathish; Griffin, Nicholas W; Drewry, Lisa L; Petri, William A; Haque, Rashidul; Ahmed, Tahmeed; Gordon, Jeffrey I

    2014-11-20

    Given the global burden of diarrhoeal diseases, it is important to understand how members of the gut microbiota affect the risk for, course of, and recovery from disease in children and adults. The acute, voluminous diarrhoea caused by Vibrio cholerae represents a dramatic example of enteropathogen invasion and gut microbial community disruption. Here we conduct a detailed time-series metagenomic study of faecal microbiota collected during the acute diarrhoeal and recovery phases of cholera in a cohort of Bangladeshi adults living in an area with a high burden of disease. We find that recovery is characterized by a pattern of accumulation of bacterial taxa that shows similarities to the pattern of assembly/maturation of the gut microbiota in healthy Bangladeshi children. To define the underlying mechanisms, we introduce into gnotobiotic mice an artificial community composed of human gut bacterial species that directly correlate with recovery from cholera in adults and are indicative of normal microbiota maturation in healthy Bangladeshi children. One of the species, Ruminococcus obeum, exhibits consistent increases in its relative abundance upon V. cholerae infection of the mice. Follow-up analyses, including mono- and co-colonization studies, establish that R. obeum restricts V. cholerae colonization, that R. obeum luxS (autoinducer-2 (AI-2) synthase) expression and AI-2 production increase significantly with V. cholerae invasion, and that R. obeum AI-2 causes quorum-sensing-mediated repression of several V. cholerae colonization factors. Co-colonization with V. cholerae mutants discloses that R. obeum AI-2 reduces Vibrio colonization/pathogenicity through a novel pathway that does not depend on the V. cholerae AI-2 sensor, LuxP. The approach described can be used to mine the gut microbiota of Bangladeshi or other populations for members that use autoinducers and/or other mechanisms to limit colonization with V. cholerae, or conceivably other enteropathogens.

  19. 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

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

  20. A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images.

    Science.gov (United States)

    Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong

    2016-08-19

    A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians.

  1. BENCHMARK EVALUATION OF HOG DESCRIPTORS AS FEATURES FOR CLASSIFICATION OF TRAFFIC SIGNS

    Directory of Open Access Journals (Sweden)

    Hasan Fleyeh

    2013-12-01

    Full Text Available The purpose of this paper is to analyze the performance of the Histograms of Oriented Gradients (HOG as descriptors for traffic signs recognition. The test dataset consists of speed limit traffic signs because of their high inter-class similarities. HOG features of speed limit signs, which were extracted from different traffic scenes, were computed and a Gentle AdaBoost classifier was invoked to evaluate the different features. The performance of HOG was tested with a dataset consisting of 1727 Swedish speed signs images. Different numbers of HOG features per descriptor, ranging from 36 features up 396 features, were computed for each traffic sign in the benchmark testing. The results show that HOG features perform high classification rate as the Gentle AdaBoost classification rate was 99.42%, and they are suitable to real time traffic sign recognition. However, it is found that changing the number of orientation bins has insignificant effect on the classification rate. In addition to this, HOG descriptors are not robust with respect to sign orientation.

  2. A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images

    Science.gov (United States)

    Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong

    2016-01-01

    A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles’ in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians. PMID:27548179

  3. Cholera in Zimbabwe: Developing an Educational Response to a Health Crisis

    Science.gov (United States)

    Mandikonza, Caleb; Musindo, Beatrice; Taylor, Jim

    2011-01-01

    In February 2009, the World Health Organization (WHO) reported that the cholera epidemic in Zimbabwe had claimed 3,300 lives and infected 66,000 people--greater than the toll of that disease in the whole of Africa in most years. How is it possible that a disease such as cholera can have such a devastating effect in modern times? How should one…

  4. Cholera in Zimbabwe: Developing an Educational Response to a Health Crisis

    Science.gov (United States)

    Mandikonza, Caleb; Musindo, Beatrice; Taylor, Jim

    2011-01-01

    In February 2009, the World Health Organization (WHO) reported that the cholera epidemic in Zimbabwe had claimed 3,300 lives and infected 66,000 people--greater than the toll of that disease in the whole of Africa in most years. How is it possible that a disease such as cholera can have such a devastating effect in modern times? How should one…

  5. Efficacy of a live attenuated vaccine in classical swine fever virus postnatally persistently infected pigs.

    Science.gov (United States)

    Muñoz-González, Sara; Perez-Simó, Marta; Muñoz, Marta; Bohorquez, José Alejandro; Rosell, Rosa; Summerfield, Artur; Domingo, Mariano; Ruggli, Nicolas; Ganges, Llilianne

    2015-07-09

    Classical swine fever (CSF) causes major losses in pig farming, with various degrees of disease severity. Efficient live attenuated vaccines against classical swine fever virus (CSFV) are used routinely in endemic countries. However, despite intensive vaccination programs in these areas for more than 20 years, CSF has not been eradicated. Molecular epidemiology studies in these regions suggests that the virus circulating in the field has evolved under the positive selection pressure exerted by the immune response to the vaccine, leading to new attenuated viral variants. Recent work by our group demonstrated that a high proportion of persistently infected piglets can be generated by early postnatal infection with low and moderately virulent CSFV strains. Here, we studied the immune response to a hog cholera lapinised virus vaccine (HCLV), C-strain, in six-week-old persistently infected pigs following post-natal infection. CSFV-negative pigs were vaccinated as controls. The humoral and interferon gamma responses as well as the CSFV RNA loads were monitored for 21 days post-vaccination. No vaccine viral RNA was detected in the serum samples and tonsils from CSFV postnatally persistently infected pigs for 21 days post-vaccination. Furthermore, no E2-specific antibody response or neutralising antibody titres were shown in CSFV persistently infected vaccinated animals. Likewise, no of IFN-gamma producing cell response against CSFV or PHA was observed. To our knowledge, this is the first report demonstrating the absence of a response to vaccination in CSFV persistently infected pigs.

  6. Cholera vaccination in urban Haiti

    National Research Council Canada - National Science Library

    Rouzier, Vanessa; Severe, Karine; Juste, Marc Antoine Jean; Peck, Mireille; Perodin, Christian; Severe, Patrice; Deschamps, Marie Marcelle; Verdier, Rose Irene; Prince, Sabine; Francois, Jeannot; Cadet, Jean Ronald; Guillaume, Florence D; Wright, Peter F; Pape, Jean W

    2013-01-01

    Successful and sustained efforts have been made to curtail the major cholera epidemic that occurred in Haiti in 2010 with the promotion of hygiene and sanitation measures, training of health personnel...

  7. Chromosome Segregation in Vibrio cholerae

    OpenAIRE

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

    2014-01-01

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

  8. Assessing hog lagoon waste contamination in the Cape Fear Watershed using Bacteroidetes 16S rRNA gene pyrosequencing.

    Science.gov (United States)

    Arfken, Ann M; Song, Bongkeun; Mallin, Michael A

    2015-09-01

    Hog lagoons can be major sources of waste and nutrient contamination to watersheds adjacent to pig farms. Fecal source tracking methods targeting Bacteroidetes 16S rRNA genes in pig fecal matter may underestimate or fail to detect hog lagoon contamination in riverine environments. In order to detect hog lagoon wastewater contamination in the Cape Fear Watershed, where a large number of hog farms are present, we conducted pyrosequencing analyses of Bacteroidetes 16S rRNA genes in hog lagoon waste and identified new hog lagoon-specific marker sequences. Additional pyrosequencing analyses of Bacteroidetes 16S rRNA genes were conducted with surface water samples collected at 4 sites during 5 months in the Cape Fear Watershed. Using an operational taxonomic unit (OTU) identity cutoff value of 97 %, these newly identified hog lagoon markers were found in 3 of the river samples, while only 1 sample contained the pig fecal marker. In the sample containing the pig fecal marker, there was a relatively high percentage (14.1 %) of the hog lagoon markers and a low pig fecal marker relative abundance of 0.4 % in the Bacteroidetes 16S rRNA gene sequences. This suggests that hog lagoon contamination must be somewhat significant in order for pig fecal markers to be detected, and low levels of hog lagoon contamination cannot be detected targeting only pig-specific fecal markers. Thus, new hog lagoon markers have a better detection capacity for lagoon waste contamination, and in conjunction with a pig fecal marker, provide a more comprehensive and accurate detection of hog lagoon waste contamination in susceptible watersheds.

  9. Arabic sign language recognition based on HOG descriptor

    Science.gov (United States)

    Ben Jmaa, Ahmed; Mahdi, Walid; Ben Jemaa, Yousra; Ben Hamadou, Abdelmajid

    2017-02-01

    We present in this paper a new approach for Arabic sign language (ArSL) alphabet recognition using hand gesture analysis. This analysis consists in extracting a histogram of oriented gradient (HOG) features from a hand image and then using them to generate an SVM Models. Which will be used to recognize the ArSL alphabet in real-time from hand gesture using a Microsoft Kinect camera. Our approach involves three steps: (i) Hand detection and localization using a Microsoft Kinect camera, (ii) hand segmentation and (iii) feature extraction using Arabic alphabet recognition. One each input image first obtained by using a depth sensor, we apply our method based on hand anatomy to segment hand and eliminate all the errors pixels. This approach is invariant to scale, to rotation and to translation of the hand. Some experimental results show the effectiveness of our new approach. Experiment revealed that the proposed ArSL system is able to recognize the ArSL with an accuracy of 90.12%.

  10. Partial characterization of hog renin purified by affinity chromatography.

    Science.gov (United States)

    Devaux, C; Ménard, J; Sicard, P; Corvol, P

    1976-05-01

    A method has been set up to purify renin on a large scale by affinity chromatography using Pepstatin, a potent inhibitor of renin, as a ligand. Pepstatin was covalently coupled to Sepharose via six different spacer 'arms'. The Sepharose-hexamethylenediamino-Pepstatin appeared to be the better derivative for renin purification even at a concentration as low as 160 nmol of Pepstatin/ml of moist gel. Renin was extracted from 100 kg of hog kidneys and semi-purified by ammonium sulfate precipitations and chromatography on DEAE-cellulose. The active fraction (48.5 g of proteins) was applied on a 500-ml affinity column. Renin was eluted in the starting buffer containing 6 M urea. Renin was purified 120-fold by the affinity chromatography step with a 79% recovery. Physico-chemical characterization of highly purified renin was performed. Isoelectrofocusing on a pH gradient from 3 to 6 showed a major peak with an isoelectric point (pI) of 4.95 and a minor peak (pI = 4.70). Polyacrylamide gel electrophoresis, pH 7.8, at different gel concentrations, showed a single peak of renin activity which was found in the major protein band. Molecular size estimated on agarose-acrylamide gel filtration was 40 000. All these physical parameters were similar before and after purification.

  11. Large scale purification of hog renin. Physicochemical characterization.

    Science.gov (United States)

    Corvol, P; Devaux, C; Ito, T; Sicard, P; Ducloux, J; Menard, J

    1977-11-01

    Renin was purified from 47 kg of hog kidney to produce enough enzyme for enzymatic and physicochemical characterization. The procedure included extraction at pH 3.5 in the presence of protease inhibitors, two ammonium sulfate precipitations, ion exchange chromatography on Sepharose-hexamethylenediamino-pepstatin gel, gel filtration, and isoelectric focusing. Renin, 2.3 mg, with a specific activity of 1,100 GU/mg of protein was obtained with about 70,000-fold purification and 16% overall recovery. The purity criteria were: (1) a single band on sodium dodecyl sulfate (SDS)-gel electrophoresis, (2) same retardation factor on polyacrylamide gel electrophoresis for renin activity, protein and glycoprotein coloration. Renin was characterized by its stability at--20 degrees C, pH 6.5; its molecular weight on SDS-gel electrophoresis, 36,800; its relative mobility on polyacrylamide gel electrophoresis at pH 7.8; its isoelectric point, 5.15; its amino acid composition, which revealed that renin is a glycoprotein; and its Michaelis constant on tetradecapeptide substrate at pH 6.6, Km = 7.7 X 10(-6) M.

  12. Optimizing settling conditions for treatment of liquid hog manure.

    Science.gov (United States)

    Trias, M; Mortula, M M; Hu, Z; Gagnon, G A

    2004-08-01

    Sedimentation is a widely used separation method for treating agricultural waste. There are several chemical and biological characteristics, which can affect the settling behavior and liquid waste. The optimization of cation balances and potential for nitrification are among these processes. In addition to sedimentation, it can also affect the dewaterability of the samples. Liquid hog manure was used during the laboratory based experiments to investigate the effects of Ca2+ and Mg2+ ions and nitrification inhibition on the overall settling and dewatering characteristics. The results indicated that settling and dewatering characteristics improved during the course of the experiments. However, the improvement in settling and dewatering characteristics was inconsistent and not statistically significant. Cation addition in aerated reactor increased the highest settling velocity (94%). The improvement in dewaterability, as quantified by capillary suction time, was also not consistent. The greatest filterability observed in the supernatant was a capillary suction time of 40 s for a M:D ratio of 2:1. Initial NH 4 + concentration was more important than the nitrification inhibitor, as the presence of nitrification inhibitor increased the nitrification rate by over 300% because of the high initial NH 4 + concentration and low volatile suspended solid. The results from these experiments provide the basis for further field evaluation of cation optimization.

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

    OpenAIRE

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

    1985-01-01

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

  14. Feeding the Hog Industry in North Carolina: Agri-Industrial Restructuring in Hog Farming and Its Implications for the US Periphery

    Directory of Open Access Journals (Sweden)

    Donnie Charleston

    2004-03-01

    Full Text Available Hog farms bring with them employment to remote areas but they also bring environmental problems. What determines the location of the large-scale factory farm? It is race? Is it capital availability? The answer seems to be capital availablity

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

    OpenAIRE

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

    1994-01-01

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

  16. Characterization of the Hog1 MAPK pathway in the entomopathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Liu, Jing; Wang, Zhi-Kang; Sun, Huan-Huan; Ying, Sheng-Hua; Feng, Ming-Guang

    2017-01-11

    High-osmolarity glycerol (HOG) pathway required for yeast osmoregulation relies upon the mitogen-activated protein kinase (MAPK) Hog1 cascade that comprise the MAPKKKs Ssk2/Ssk22 and Ste11 converging on the MAPKK Pbs2. Here we show a Hog1 cascade with the unique MAPKKK Ssk2 acting in Beauveria bassiana. Hypersensitivity to high osmolarity and high resistance to fludioxonil fungicide appeared in Δssk2, Δpbs2 and Δhog1 mutants whereas the two hallmark phenotypes were reversed in Δste11. Increased sensitivity to heat shock and decreased sensitivity to cell wall perturbation also occurred in the three mutants but not in Δste11 although antioxidant phenotypes were different in all deletion mutants. Intriguingly, signals of Hog1 phosphorylation induced by osmotic, oxidative and thermal cues were present in Δste11 but absent in Δssk2 and Δpbs2. Moreover, vegetative growth on minimal media with different carbon/nitrogen sources was much more suppressed in Δste11 and Δssk2 than in Δpbs2 and Δhog1 although all mutants suffered similar, but severe, conidiation defects on a standard medium. Normal host infection was abolished in Δste11 while virulence was differentially attenuated in other mutants. Our findings exclude Ste11 from the Hog1 cascade that regulates multiple stress responses and environmental adaptation of B. bassiana and perhaps other filamentous fungi. This article is protected by copyright. All rights reserved.

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

    Science.gov (United States)

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

    2016-10-01

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

  18. 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

  19. Urban cholera transmission hotspots and their implications for reactive vaccination: evidence from Bissau city, Guinea bissau.

    Science.gov (United States)

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

    2012-01-01

    Use of cholera vaccines in response to epidemics (reactive vaccination) may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of a cholera epidemic. We fit a spatially explicit meta-population model of cholera transmission within Bissau City to data from 7,551 suspected cholera cases from a 2008 epidemic. We estimated the effect reactive vaccination campaigns would have had on the epidemic under different levels of vaccine coverage and campaign start dates. We compared highly focused and diffuse strategies for distributing vaccine throughout the city. We found wide variation in the efficiency of cholera transmission both within and between areas of the city. "Hotspots", where transmission was most efficient, appear to drive the epidemic. In particular one area, Bandim, was a necessary driver of the 2008 epidemic in Bissau City. If vaccine supply were limited but could have been distributed within the first 80 days of the epidemic, targeting vaccination at Bandim would have averted the most cases both within this area and throughout the city. Regardless of the distribution strategy used, timely distribution of vaccine in response to an ongoing cholera epidemic can prevent cases and save lives. Reactive vaccination can be a useful tool for controlling cholera epidemics, especially in urban areas like Bissau City. Particular neighborhoods may be responsible for driving a city's cholera epidemic; timely and targeted reactive vaccination at such neighborhoods may be the most effective way to prevent cholera cases both within that neighborhood and throughout the city.

  20. Complementary function of mitogen-activated protein kinase Hog1 from Trichosporonoides megachiliensis in Saccharomyces cerevisiae under hyper-osmotic stress.

    Science.gov (United States)

    Yoshida, Junjiro; Kobayashi, Yosuke; Tanaka, Yosuke; Koyama, Yoshiyuki; Ogihara, Jun; Kato, Jun; Shima, Jun; Kasumi, Takafumi

    2013-02-01

    A (TmHog1) gene encoding a mitogen-activated protein kinase (MAPK) homologous to Saccharomyces cerevisiae Hog1 (ScHog1) involved in hyper-osmotic stress signaling was isolated from Trichosporonoides megachiliensis SN-124A, an erythritol-producing yeast. Although TmHog1, like other Hog1 homologs, encoded a kinase catalytic domain containing TGY motif, it was 50-60 amino acid residues shorter than the ScHog1. A TmHog1 transgene rescued the osmotic sensitivity and glycerol production defect of S. cerevisiae hog1Δ, a highly osmo-sensitive strain that does not produce glycerol, a compatible solute, during osmotic stress. Functional analyses of chimeric Hog1 proteins constructed from ScHog1 and TmHog1 sequences indicated that the C-terminal region of TmHog1 is more effective for glycerol biosynthesis than ScHog1 under osmotic stress. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Invariant recognition of polychromatic images of Vibrio cholerae 01

    Science.gov (United States)

    Alvarez-Borrego, Josue; Mourino-Perez, Rosa R.; Cristobal, Gabriel; Pech-Pacheco, Jose L.

    2002-04-01

    Cholera is an acute intestinal infectious disease. It has claimed many lives throughout history, and it continues to be a global health threat. Cholera is considered one of the most important emergence diseases due its relation with global climate changes. Automated methods such as optical systems represent a new trend to make more accurate measurements of the presence and quantity of this microorganism in its natural environment. Automatic systems eliminate observer bias and reduce the analysis time. We evaluate the utility of coherent optical systems with invariant correlation for the recognition of Vibrio cholerae O1. Images of scenes are recorded with a CCD camera and decomposed in three RGB channels. A numeric simulation is developed to identify the bacteria in the different samples through an invariant correlation technique. There is no variation when we repeat the correlation and the variation between images correlation is minimum. The position-, scale-, and rotation-invariant recognition is made with a scale transform through the Mellin transform. The algorithm to recognize Vibrio cholerae O1 is the presence of correlation peaks in the green channel output and their absence in red and blue channels. The discrimination criterion is the presence of correlation peaks in red, green, and blue channels.

  2. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

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

    2016-01-01

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

  3. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

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

    2016-01-01

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

  4. Fish as Hosts of Vibrio cholerae

    Science.gov (United States)

    Halpern, Malka; Izhaki, Ido

    2017-01-01

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

  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. Fish as Hosts of Vibrio cholerae.

    Science.gov (United States)

    Halpern, Malka; Izhaki, Ido

    2017-01-01

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

  7. Binding of cholera toxin to Giardia lamblia.

    OpenAIRE

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

    1987-01-01

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

  8. Changing Structure and Sustainable Development for China’s Hog Sector

    Directory of Open Access Journals (Sweden)

    Xiaoheng Zhang

    2017-01-01

    Full Text Available Supply shortages and competitive disadvantages are the main problems faced by China’s hog sector. The non-essential import of pork products, triggered by competitive disadvantages, poses great challenges to hog farms. Structural changes are an important policy concern in China and elsewhere. Previous literature has ignored whether the ongoing structural changes from backyard to large farms can contribute to sustainable development. This study adopts the micro-level data of hog farms collected from Jiangsu Province, and uses a two-step metafrontier model and a primal system approach. The empirical results reveal that the ongoing structural changes are capable of boosting the growth in output in China’s hog sector, since the stronger increase in comparable technical efficiency compensates for the inappropriate technology. Furthermore, the ongoing structural changes are also beneficial in the reduction of production costs and in improving competitiveness in China’s hog sector. The decline in technical and allocative inefficiency costs, particularly for technical inefficiency costs, contributes to the cost advantage with the increasing farm size.

  9. Pheromone-induced morphogenesis improves osmoadaptation capacity by activating the HOG MAPK pathway.

    Science.gov (United States)

    Baltanás, Rodrigo; Bush, Alan; Couto, Alicia; Durrieu, Lucía; Hohmann, Stefan; Colman-Lerner, Alejandro

    2013-04-23

    Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are difficult to predict. We investigate the response to mating pheromone of yeast cells adapted to high osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase (MAPK) cascades: the pheromone response (PR) and the cell wall integrity (CWI) response. Although the PR MAPK pathway shares components with a third MAPK pathway, the high osmolarity (HOG) response, each one is normally only activated by its cognate stimulus, a phenomenon called insulation. We found that in cells adapted to high osmolarity, PR activated the HOG pathway in a pheromone- and osmolarity-dependent manner. Activation of HOG by the PR was not due to loss of insulation, but rather a response to a reduction in internal osmolarity, which resulted from an increase in glycerol release caused by the PR. By analyzing single-cell time courses, we found that stimulation of HOG occurred in discrete bursts that coincided with the "shmooing" morphogenetic process. Activation required the polarisome, the CWI MAPK Slt2, and the aquaglyceroporin Fps1. HOG activation resulted in high glycerol turnover, which improved adaptability to rapid changes in osmolarity. Our work shows how a differentiation signal can recruit a second, unrelated sensory pathway to fine-tune yeast response in a complex environment.

  10. Control of the cell cycle progression by the MAPK Hog1

    Directory of Open Access Journals (Sweden)

    Josep Clotet

    2013-02-01

    Full Text Available Eukaryotic cells coordinate various intracellular activities in response to environmental stresses, activating an adaptive program to maximize the probability of survival and proliferation. Cells transduce diverse cellular stimuli by multiple mitogen-activated protein kinase (MAPK cascades. MAPK are key signal transduction kinases required to respond to stress. A prototypical member of the MAPK family is the yeast high osmolarity glycerol (Hog1. Activation of Hog1 results in the generation of a set of adaptive responses that leads to the modulation of several aspects of cell physiology that are essential for cell survival, such as gene expression, translation, and morphogenesis. This review focuses on the control of cell cycle progression by Hog1 which is critical for cell survival in response to stress conditions.

  11. Adsorption isotherms of hog plum (Spondias mombin L. pulp powder obtained by spray dryer

    Directory of Open Access Journals (Sweden)

    Luís Gomes de Moura Neto

    2015-05-01

    Full Text Available Food sorption isotherms are highly important to predict drying time and storage conditions of a product. Current assay evaluates the behavior of adsorption isotherms of hog plum powder obtained by spray-dryer, through mathematical models. GAB, BET, Henderson and Oswin models were adjusted to the experimental data at 25, 30, 35 and 40ºC. The BET model best adjusted to the atomized hog plum for all temperatures tested, with an error ranging between 8.45 and 11.17%. The coefficient of determination (R2 had rates higher than 0.9900 for all the adjusted models. The behavior of hog plum powder adsorption isotherms was classified as Type III.

  12. Remodeling of global transcription patterns of Cryptococcus neoformans genes mediated by the stress-activated HOG signaling pathways.

    Science.gov (United States)

    Ko, Young-Joon; Yu, Yeong Man; Kim, Gyu-Bum; Lee, Gir-Won; Maeng, Pil Jae; Kim, Sangsoo; Floyd, Anna; Heitman, Joseph; Bahn, Yong-Sun

    2009-08-01

    The ability to sense and adapt to a hostile host environment is a crucial element for virulence of pathogenic fungi, including Cryptococcus neoformans. These cellular responses are evoked by diverse signaling cascades, including the stress-activated HOG pathway. Despite previous analysis of central components of the HOG pathway, its downstream signaling network is poorly characterized in C. neoformans. Here we performed comparative transcriptome analysis with HOG signaling mutants to explore stress-regulated genes and their correlation with the HOG pathway in C. neoformans. In this study, we not only provide important insights into remodeling patterns of global gene expression for counteracting external stresses but also elucidate novel characteristics of the HOG pathway in C. neoformans. First, inhibition of the HOG pathway increases expression of ergosterol biosynthesis genes and cellular ergosterol content, conferring a striking synergistic antifungal activity with amphotericin B and providing an excellent opportunity to develop a novel therapeutic method for treatment of cryptococcosis. Second, a number of cadmium-sensitive genes are differentially regulated by the HOG pathway, and their mutation causes resistance to cadmium. Finally, we have discovered novel stress defense and HOG-dependent genes, which encode a sodium/potassium efflux pump, protein kinase, multidrug transporter system, and elements of the ubiquitin-dependent system.

  13. 7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market...

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

    Science.gov (United States)

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

    2014-05-01

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

  15. Toll-like receptor 2 is upregulated by hog confinement dust in an IL-6 dependent manner in the airway epithelium

    OpenAIRE

    Bailey, KL; Poole, JA; Mathisen, TL; Wyatt, TA; Von Essen, SG; Romberger, DJ

    2008-01-01

    Hog confinement workers are at high risk to develop chronic bronchitis as a result of their exposure to organic dust. Chronic bronchitis is characterized by inflammatory changes of the airway epithelium. A key mediator in inflammation is Toll-like receptor 2 (TLR2). We investigated the role of TLR2 in pulmonary inflammation induced by hog confinement dust. Normal Human Bronchial Epithelial Cells (NHBE) were grown in culture and exposed to hog confinement dust extract. Hog confinement dust upr...

  16. A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images

    Directory of Open Access Journals (Sweden)

    Yongzheng Xu

    2016-08-01

    Full Text Available A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J and linear SVM classifier with HOG feature (HOG + SVM methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV images. As both V-J and HOG + SVM are sensitive to on-road vehicles’ in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians.

  17. Cholera Vaccination in Urban Haiti

    Science.gov (United States)

    Rouzier, Vanessa; Severe, Karine; Juste, Marc Antoine Jean; Peck, Mireille; Perodin, Christian; Severe, Patrice; Deschamps, Marie Marcelle; Verdier, Rose Irene; Prince, Sabine; Francois, Jeannot; Cadet, Jean Ronald; Guillaume, Florence D.; Wright, Peter F.; Pape, Jean W.

    2013-01-01

    Successful and sustained efforts have been made to curtail the major cholera epidemic that occurred in Haiti in 2010 with the promotion of hygiene and sanitation measures, training of health personnel and establishment of treatment centers nationwide. Oral cholera vaccine (OCV) was introduced by the Haitian Ministry of Health as a pilot project in urban and rural areas. This paper reports the successful OCV pilot project led by GHESKIO Centers in the urban slums of Port-au-Prince where 52,357 persons received dose 1 and 90.8% received dose 2; estimated coverage of the at-risk community was 75%. This pilot study demonstrated the effort, community mobilization, and organizational capacity necessary to achieve these results in a challenging setting. The OCV intervention paved the way for the recent launching of a national cholera vaccination program integrated in a long-term ambitious and comprehensive plan to address Haiti's critical need in water security and sanitation. PMID:24106194

  18. Chromosome segregation in Vibrio cholerae.

    Science.gov (United States)

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

    2014-01-01

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

  19. Epidemiology of cholera in the Philippines.

    Directory of Open Access Journals (Sweden)

    Anna Lena Lopez

    2015-01-01

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

  20. Epidemiology of Cholera in the Philippines

    Science.gov (United States)

    Lopez, Anna Lena; Macasaet, Lino Y.; Ylade, Michelle; Tayag, Enrique A.; Ali, Mohammad

    2015-01-01

    Background Despite being a cholera-endemic country, data on cholera in the Philippines remain sparse. Knowing the areas where cholera is known to occur and the factors that lead to its occurrence will assist in planning preventive measures and disaster mitigation. Methods Using sentinel surveillance data, PubMed and ProMED searches covering information from 2008–2013 and event-based surveillance reports from 2010–2013, we assessed the epidemiology of cholera in the Philippines. Using spatial log regression, we assessed the role of water, sanitation and population density on the incidence of cholera. Results and Discussion We identified 12 articles from ProMED and none from PubMed that reported on cholera in the Philippines from 2008 to 2013. Data from ProMed and surveillance revealed 42,071 suspected and confirmed cholera cases reported from 2008 to 2013, among which only 5,006 were confirmed. 38 (47%) of 81 provinces and metropolitan regions reported at least one confirmed case of cholera and 32 (40%) reported at least one suspected case. The overall case fatality ratio in sentinel sites was 0.62%, but was 2% in outbreaks. All age groups were affected. Using both confirmed and suspected cholera cases, the average annual incidence in 2010–2013 was 9.1 per 100,000 population. Poor access to improved sanitation was consistently associated with higher cholera incidence. Paradoxically, access to improved water sources was associated with higher cholera incidence using both suspected and confirmed cholera data sources. This finding may have been due to the breakdown in the infrastructure and non-chlorination of water supplies, emphasizing the need to maintain public water systems. Conclusion Our findings confirm that cholera affects a large proportion of the provinces in the country. Identifying areas most at risk for cholera will support the development and implementation of policies to minimize the morbidity and mortality due to this disease. PMID:25569505

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

    African Journals Online (AJOL)

    Risk factors associated with cholera in Harare City, Zimbabwe, 2008. ... Two suspected cholera cases at Beatrice Road Infectious Diseases Hospital were reported ... Lack of water, low knowledge on cholera prevention measures and delays in ...

  2. Successful Multi-partner Response to a Cholera Outbreak

    African Journals Online (AJOL)

    46987.2

    was one of the three established cholera treatment centres. (CTC) and other two being ... Cholera disease caused by Vibrio cholera continues to be a global threat to ... disease of two hours to five days facilitates the potentially fast spreading.

  3. A rapid assessment of drinking water quality in informal settlements after a cholera outbreak in Nairobi, Kenya.

    Science.gov (United States)

    Blanton, Elizabeth; Wilhelm, Natalie; O'Reilly, Ciara; Muhonja, Everline; Karoki, Solomon; Ope, Maurice; Langat, Daniel; Omolo, Jared; Wamola, Newton; Oundo, Joseph; Hoekstra, Robert; Ayers, Tracy; De Cock, Kevin; Breiman, Robert; Mintz, Eric; Lantagne, Daniele

    2015-09-01

    Populations living in informal settlements with inadequate water and sanitation infrastructure are at risk of epidemic disease. In 2010, we conducted 398 household surveys in two informal settlements in Nairobi, Kenya with isolated cholera cases. We tested source and household water for free chlorine residual (FCR) and Escherichia coli in approximately 200 households. International guidelines are ≥0.5 mg/L FCR at source, ≥0.2 mg/L at household, and cholera transmission in informal settlements.

  4. 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.

  5. Dynamics in genome evolution of Vibrio cholerae.

    Science.gov (United States)

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

    2014-04-01

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

  6. Antibiotic Susceptibility Patterns of Vibrio cholerae isolates

    Directory of Open Access Journals (Sweden)

    S D Shrestha

    2010-09-01

    Full Text Available INTRODUCTION: Cholera is one of the most common diarrhoeal diseases in Nepal. Etiological agent of cholera is Vibrio cholerae which removes essential body fluids, salts and vital nutrients, which are necessary for life causing dehydration and malnutrition. Emerging antimicrobial resistant is common. The aim of the present study was to determine the antibiotic susceptibility pattern of cholera patients in Nepal. METHODS: All the laboratory works were conducted in the bacteriology section of National Public Health Laboratory, Teku from March to September 2005. During this period a total of 340 stool samples from diarrhoeal patients were collected and processed according to the standard laboratory methods. Each patient suffering from diarrhoea was directly interviewed for his or her clinical history during sample collection. RESULTS: A total of 340 stool samples were processed and studied from both sex including all ages of patients. Among the processed sample 53 Vibrio cholerae cases were found. All isolated Vibrio cholerae O1 were El Tor, Inaba. All isolated (100% Vibrio cholerae O1 were sensitive to Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline whereas all were resistant to Nalidixic acid and Cotrimoxazole. Only 15.1% cases were sensitive to Furazolidone whereas 84.9% were resistant. CONCLUSION: All V. cholerae strains isolated in this study were found resistant to Multi Drug Resistant (resistant to at least two antibiotics of different group. Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline were found still more potent antibiotics against Vibrio cholerae isolated during the study. Keywords: antibiotics, susceptibility, Vibrio cholera.

  7. 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.

  8. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

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

    2012-01-01

    . 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...

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Kanungo Suman

    2012-09-01

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

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

    Science.gov (United States)

    Kanungo, Suman; Sur, Dipika; Ali, Mohammad; You, Young Ae; Pal, Debottam; Manna, Byomkesh; Niyogi, Swapan K; Sarkar, Banwarilal; Bhattacharya, Sujit K; Clemens, John D; Nair, G Balakrish

    2012-09-28

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

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

    Directory of Open Access Journals (Sweden)

    Yunus Mohammad

    2010-03-01

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

  13. Segmental HOG: new descriptor for glomerulus detection in kidney microscopy image.

    Science.gov (United States)

    Kato, Tsuyoshi; Relator, Raissa; Ngouv, Hayliang; Hirohashi, Yoshihiro; Takaki, Osamu; Kakimoto, Tetsuhiro; Okada, Kinya

    2015-09-30

    The detection of the glomeruli is a key step in the histopathological evaluation of microscopic images of the kidneys. However, the task of automatic detection of the glomeruli poses challenges owing to the differences in their sizes and shapes in renal sections as well as the extensive variations in their intensities due to heterogeneity in immunohistochemistry staining. Although the rectangular histogram of oriented gradients (Rectangular HOG) is a widely recognized powerful descriptor for general object detection, it shows many false positives owing to the aforementioned difficulties in the context of glomeruli detection. A new descriptor referred to as Segmental HOG was developed to perform a comprehensive detection of hundreds of glomeruli in images of whole kidney sections. The new descriptor possesses flexible blocks that can be adaptively fitted to input images in order to acquire robustness for the detection of the glomeruli. Moreover, the novel segmentation technique employed herewith generates high-quality segmentation outputs, and the algorithm is assured to converge to an optimal solution. Consequently, experiments using real-world image data revealed that Segmental HOG achieved significant improvements in detection performance compared to Rectangular HOG. The proposed descriptor for glomeruli detection presents promising results, and it is expected to be useful in pathological evaluation.

  14. PREVALENCE OF YERSINIA ENTEROCOLITICA IN MARKET WEIGHT HOGS IN THE UNITED STATES

    Science.gov (United States)

    Pigs are the major animal reservoir for Y. enterocolitica strains, which are potentially pathogenic for humans. The goals of this study were (1) to estimate the individual animal and on-farm prevalences of Y. enterocolitica in hogs based on tonsil samples collected during National Animal Health Mon...

  15. Do Transaction Costs and Risk Preferences Influence Marketing Arrangements in the Illinois Hog Industry?

    NARCIS (Netherlands)

    Franken, J.R.V.; Pennings, J.M.E.; Garcia, P.

    2009-01-01

    Risk reduction and transaction costs are often used to explain contracting in the U.S. hog industry with little empirical support. Using a unified conceptual framework that draws from risk behavior and transaction cost theories, in combination with unique survey and accounting data, we demonstrate

  16. Radiocesium concentrations in two populations of naturally contaminated feral hogs (Sus scrofa domesticus). [/sup 137/Cs

    Energy Technology Data Exchange (ETDEWEB)

    Stribling, H.L.

    1978-12-01

    Two populations of feral hogs (Sus scrofa domesticus) were studied during the summer and winter seasons from 1976 to 1978 in order to determine concentrations, distributional patterns, and predictability of cesium-137 in the whole body and various body compartments of these animals. One population inhabited the Savannah River Plant (SRP) Aiken, South Carolina, an area contaminated by reactor waste and natural fallout; the other inhabited Ossabaw Island (OI), Georgia, an area contaminated by natural fallout alone. Whole-body burdens on the SRP averaged about 2 and about 1.5 times higher than those samples on OI during the summer and winter seasons, respectively. Radiocesium levels in feral hogs on SRP were not only influenced by the additional source of contamination but apparently fluctuated seasonally as well since the whole-body burdens of SRP hogs sampled were about 1.5 times higher in the summer than in the winter. Levels of cesium-137 in skeletal muscle have decreased in the SRP feral hog population since 1968. On the SRP, feces best predicted whole-body burdens with an r/sup 2/ of 0.67. All internal organs examined predicted levels in skeletal muscle well for SRP animals but best predictability of muscle (R/sup 2/ = 0.94) was achieved when brain, liver, and feces were combined in a multiple regression equation. Muscle was the best predictor of cesium-137 in all body compartments.

  17. 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

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

    OpenAIRE

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

    2016-01-01

    Recurrent cholera causes significant morbidity and mortality among the growing population of Dhaka, the capital city of Bangladesh. Previous studies have demonstrated that household contacts of cholera patients are at >100 times higher risk of cholera during the week after the presentation of the index patient. Our prospective study investigated the mode of transmission of Vibrio cholerae, the cause of cholera, in the households of cholera patients in Dhaka city. Of total 420 rectal swab samp...

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

    OpenAIRE

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

    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. Thes...

  20. 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.

  1. Vibrio cholerae strains possess multiple strategies for abiotic and biotic surface colonization.

    Science.gov (United States)

    Mueller, Ryan S; McDougald, Diane; Cusumano, Danielle; Sodhi, Nidhi; Kjelleberg, Staffan; Azam, Farooq; Bartlett, Douglas H

    2007-07-01

    Despite its notoriety as a human pathogen, Vibrio cholerae is an aquatic microbe suited to live in freshwater, estuarine, and marine environments where biofilm formation may provide a selective advantage. Here we report characterization of biofilms formed on abiotic and biotic surfaces by two non-O1/O139 V. cholerae strains, TP and SIO, and by the O1 V. cholerae strain N16961 in addition to the isolation of 44 transposon mutants of SIO and TP impaired in biofilm formation. During the course of characterizing the mutants, 30 loci which have not previously been associated with V. cholerae biofilms were identified. These loci code for proteins which perform a wide variety of functions, including amino acid metabolism, ion transport, and gene regulation. Also, when the plankton colonization abilities of strains N16961, SIO, and TP were examined, each strain showed increased colonization of dead plankton compared with colonization of live plankton (the dinoflagellate Lingulodinium polyedrum and the copepod Tigriopus californicus). Surprisingly, most of the biofilm mutants were not impaired in plankton colonization. Only mutants impaired in motility or chemotaxis showed reduced colonization. These results indicate the presence of both conserved and variable genes which influence the surface colonization properties of different V. cholerae subspecies.

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

    Science.gov (United States)

    Mudrak, Benjamin; Tamayo, Rita

    2012-05-01

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

  3. The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans.

    Science.gov (United States)

    Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

    2016-01-01

    Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

  4. Induction of melanin biosynthesis in Vibrio cholerae.

    OpenAIRE

    Coyne, V E; al-Harthi, L

    1992-01-01

    Vibrio cholerae synthesized the pigment melanin in response to specific physiological conditions that were stressful to the bacterium. Pigmentation was induced when V. cholerae was subjected to hyperosmotic stress in conjunction with elevated growth temperatures (above 30 degrees C). The salt concentration tolerated by V. cholerae was lowered by additional abiotic factors such as acidic starting pH of the growth medium and limitation of organic nutrients. Although the amount of toxin detected...

  5. Outbreak investigation of cholera in Bharuch city

    Directory of Open Access Journals (Sweden)

    Navneet G. Padhiyar, Jivraj Damor

    2011-01-01

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

  6. Controlling endemic cholera with oral vaccines.

    Directory of Open Access Journals (Sweden)

    Ira M Longini

    2007-11-01

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

  7. Cholera outbreaks in South-East Asia.

    Science.gov (United States)

    Bharati, Kaushik; Bhattacharya, S K

    2014-01-01

    This chapter highlights the cholera situation in South Asia and the Bay of Bengal region, the original 'homeland' of cholera. A detailed discussion of cholera outbreaks in individual countries in South-East Asia follows. The countries of the World Health Organization (WHO) SEARO (South-East Asia Region) region are discussed first, followed by discussions about the other countries in South-East Asia that do not fall within the purview of the WHO SEARO classification of the member countries of the region. Therefore, the chapter attempts to provide a comprehensive yet precise outline of the major cholera outbreaks that have occurred in the region over the years.

  8. Cholera outbreak--southern Sudan, 2007.

    Science.gov (United States)

    2009-04-10

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

  9. 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...

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

    Science.gov (United States)

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

    2015-05-01

    Many bacterial species are known to become viable but nonculturable (VBNC) under conditions that are unsuitable for growth. In this study, the requirements for resuscitation of VBNC-state Vibrio cholerae cells were found to change over time. Although VBNC cells could initially be converted to culturable by treatment with catalase or HT-29 cell extract, they subsequently entered a state that was not convertible to culturable by these factors. However, fluorescence microscopy revealed the presence of live cells in this state, from which VBNC cells were resuscitated by co-cultivation with HT-29 human colon adenocarcinoma cells. Ultimately, all cells entered a state from which they could not be resuscitated, even by co-cultivation with HT-29. These characteristic changes in VBNC-state cells were a common feature of strains in both V. cholerae O1 and O139 serogroups. Thus, the VBNC state of V. cholerae is not a single property but continues to change over time. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  11. Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota

    Science.gov (United States)

    Komor, S.C.

    1997-01-01

    Boron-isotope (δ11B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents δ11B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of δ11B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were −2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and δ11B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km2 watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (Zea mays L.) and soybean (Glycine max L. Merr.) fields had average B concentrations of 0.06 mg/L and δ11B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and δ11B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and δ11B values of −0.3 to 23.0o/oo. Values of δ11B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.

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

    Science.gov (United States)

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

    2009-04-07

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

  13. Comparison of immune responses to a killed bivalent whole cell oral cholera vaccine between endemic and less endemic settings.

    Science.gov (United States)

    Desai, Sachin N; Akalu, Zenebe; Teferi, Mekonnen; Manna, Byomkesh; Teshome, Samuel; Park, Ju Yeon; Yang, Jae Seung; Kim, Deok Ryun; Kanungo, Suman; Digilio, Laura

    2016-02-01

    Studies on safety, immunogenicity and efficacy of the killed, bivalent whole cell oral cholera vaccine (Shanchol) have been conducted in historically endemic settings of Asia. Recent cholera vaccination campaigns in Haiti and Guinea have also demonstrated favourable immunogenicity and effectiveness in nonendemic outbreak settings. We performed a secondary analysis, comparing immune responses of Shanchol from two randomised controlled trials performed in an endemic and a less endemic area (Addis Ababa) during a nonoutbreak setting. While Shanchol may offer some degree of immediate protection in primed populations living in cholera endemic areas, as well as being highly immunogenic in less endemic settings, understanding the characteristics of immune responses in each of these areas is vital in determining ideal dosing strategies that offer the greatest public health impact to populations from areas with varying degrees of cholera endemicity. © 2015 John Wiley & Sons Ltd.

  14. Serotype cycles in cholera dynamics

    OpenAIRE

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

    2006-01-01

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

  15. Hog and Pig Houses, Livestock, Published in 2005, 1:1200 (1in=100ft) scale, Steuben County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Hog and Pig Houses dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Observation information as of 2005. It is described...

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2014-06-01

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

  18. Vibrio cholerae-Induced Inflammation in the Neonatal Mouse Cholera Model

    Science.gov (United States)

    Bishop, Anne L.; Patimalla, Bharathi

    2014-01-01

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

  19. Population characteristics and viability of the introduced hog deer (Axis porcinus Zimmermann, 1780 in Phu Khieo Wildlife Sanctuary, Thailand

    Directory of Open Access Journals (Sweden)

    Worawidh Wajjwalku

    2012-07-01

    Full Text Available The purposes of this study were to study population characteristics of hog deer released into the wild, namely: density,age structure, sex ratio, recruitment rate, threats to hog deer, carrying capacity and inter-specific relationships, as well as toassess the population viability over time. In this study, direct observation was used to study the hog deer population characteristics,and population density was estimated from the pellet-group count method. Vortex program was used to analyze thepopulation viability. Results showed that the population density of hog deer at Thung Ka Mung (TKM in Phu Khieo WildlifeSanctuary (PKWS was 2.03-2.04 individuals/hectare (SD = 1.25. The population structure showed that the average herd sizewas 9.57 individuals. Hog deer in TKM preferred to stay with a group (91.5%, rather than being solitary (8.5%. The sex ratiofor males to females was 54.64:100, and for females to fawns was 100:26.18. The annual recruitment rate was 16.98 %. Theirpredators were Asian wild dogs, Burmese pythons, Asiatic jackals, leopard cats and clouded leopards. The mortality rate ofthe existing hog deer in TKM during the study period was 18.1%. The habitat sharing by camera traps revealed 4 ungulatespecies. They were sambar deer, barking deer, wild boar, and elephant, and their relative abundance were 28.41%, 7.38%,4.70%, and 2.01% respectively. Fifty-year simulation modeling using population viability analysis indicated the sustainabilityof this population. Hog deer population in the simulations did not exhibit sensitivity to an increase or decrease in carryingcapacity. Habitat management should be carried out continuously in TKM area, which is the main habitat for hog deer inPKWS.

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

    Directory of Open Access Journals (Sweden)

    Katherine Penrose

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

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

    Science.gov (United States)

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

    2011-02-01

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

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

    Science.gov (United States)

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

    2015-04-08

    Live attenuated vaccines are cost effective approach for preventing a broad range of infectious diseases, and thus are of great interest. However, immune-defects can predispose the patient to infections by the vaccine candidate itself. So far, few live vaccine candidates have been designed specifically for immune compromised individuals. Recently, we reported a new Salmonella Typhimurium Z234-vaccine strain (Periaswamy et al., PLoS ONE 2012;7:e45433), which was specifically attenuated in the NADPH-oxidase deficient host. In the present study, the Z234-vaccine strain was further engineered to express heterologous antigen (Vibrio cholerae toxin antigen subunit-B, i.e. CtxB) with the intention of creating a vector for simultaneous protection against Cholera and Salmonellosis. The primary aim of this study was to ensure the expression of CtxB antigen by the recombinant vaccine strain Z234-pMS101. The antigen CtxB was expressed through Z234 as a fusion protein with N-terminal signal sequence of Salmonella outer protein (SopE), an effector protein from Salmonella under the control of SopE promoter. The CtxB-expressing plasmid construct pMS101 (pM968-pSopE-ctxB) was found to be stable both in vitro and in vivo. In an oral mouse infection model, the vaccine strain Z234-pMS101 efficiently colonized the host gut. The extent of protection was confirmed after challenging the immunized hosts with live V. cholerae. Vaccinated mice showed reduced gut colonization by V. cholerae. Further assessment of immunological parameters supported the possibility of conferring effective immune response by Z234-pMS101 vaccine strain. Overall, the Z234-pMS101 vaccine strain showed potential as a promising polyvalent vaccine candidate to protect against S. Typhimurium and V. cholerae infection simultaneously. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A Single-Cell Study of a Highly Effective Hog1 Inhibitor for in Situ Yeast Cell Manipulation

    Directory of Open Access Journals (Sweden)

    Charlotte Hamngren Blomqvist

    2014-02-01

    Full Text Available We present a single cell study of a highly effective Hog1 inhibitor. For this application, we used sequential treatment of a Saccharomyces cerevisiae cell array, with the Hog1 inhibitor and osmotic stress. For this purpose, a four-inlet microfluidic chamber with controlled introduction of two different cell strains within the same experimental setting and a subsequent rapid switching between treatments was designed. Multiple cell strains within the same experiment is a unique feature which is necessary for determining the expected absent cellular response. The nuclear translocation of the cytosolic MAPK, Hog1, was monitored by fluorescence imaging of Hog1-GFP on a single-cell level. An optical tweezers setup was used for controlled cell capture and array formation. Nuclear Hog1-GFP localization was impaired for treated cells, providing evidence of a congenial microfluidic setup, where the control cells within the experiments validated its appropriateness. The chamber enables multiple treatments with incubation times in the order of seconds and the possibility to remove either of the treatments during measurement. This flexibility and the possibility to use internal control cells ensures it a valuable scientific tool for unraveling the HOG pathway, similar signal transduction pathways and other biological mechanisms where temporal resolution and real time imaging is a prerequisite.

  4. Tetra- versus Pentavalent Inhibitors of Cholera Toxin

    NARCIS (Netherlands)

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

    2015-01-01

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

  5. Tetra- versus Pentavalent Inhibitors of Cholera Toxin

    NARCIS (Netherlands)

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

    2015-01-01

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

  6. Adhesion of Vibrio cholerae to granular starches.

    Science.gov (United States)

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

    2005-08-01

    Cholera is a severe diarrheal disease caused by specific serogroups of Vibrio cholerae that are pathogenic to humans. Cholera can become epidemic and deadly without adequate medical care. Appropriate rehydration therapy can reduce the mortality rate from as much as 50% of the affected individuals to disease. To further reduce the symptoms associated with cholera, improvements in oral rehydration solution (ORS) by starch incorporation were suggested. Here, we report that V. cholerae adheres to starch granules incorporated in ORS. Adhesion of 98% of the cells was observed within 2 min when cornstarch granules were used. Other starches showed varied adhesion rates, indicating that starch source and composition play an important role in the interaction of V. cholerae and starch granules. Sugars metabolized by V. cholerae showed a repressive effect on the adhesion process. The possible mechanisms involved are discussed. Comparing V. cholerae adhesion with the adhesion of other pathogens suggests the involvement of starch degradation capabilities. This adhesion to granular starch can be used to improve ORT.

  7. Can chatter between microbes prevent cholera?

    Science.gov (United States)

    Thompson, Jessica A; Oliveira, Rita Almeida; Xavier, Karina B

    2014-12-01

    Tackling the global rise in antibiotic resistance requires new therapies against infectious microbes. A recent microbiome study identified commensal gut bacteria that reduce colonisation by the cholera pathogen, Vibrio cholerae. This antagonistic interaction might be mediated by quorum sensing, suggesting that these natural microbe-microbe interactions can help prevent infectious disease. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Mitigating the future impact of Cholera Epidemics

    CSIR Research Space (South Africa)

    Woodborne, S

    2008-11-01

    Full Text Available Cholera epidemics have been analysed using epidemiological models that depend on human-to environment- to-human spread of toxigenic Vibrio cholerae bacteria (Koelle et al. 2004, Koelle et al. 2005). Within such a framework the vulnerable human...

  9. Sub-critical water hydrolysis of hog hair for amino acid production.

    Science.gov (United States)

    Esteban, M B; García, A J; Ramos, P; Márquez, M C

    2010-04-01

    A recycling method using sub-critical water hydrolysis to convert hog hair from slaughterhouses into amino acids was developed. The influence of the reaction parameters such as temperature, time of reaction and initial substrate concentration were investigated in a batch reactor. The quality and quantity of amino acids in hydrolysates were determined and 17 kinds of amino acids were obtained. Under the tested conditions, the highest amino acid yield (325 mg/g protein) was reached at an initial substrate concentration of 10 g/l, a temperature of 250 degrees C and a reaction time of 60 min. A large amount of low-molecular weight amino acids, such alanine and glycine, was observed at these operating conditions. Sub-critical water hydrolysis was confirmed as an effective and practical process to recover amino acids from hog hair waste.

  10. Single-mode tapered optical fiber loop immunosensor II: assay of anti-cholera toxin immunoglobulins

    Science.gov (United States)

    Marks, Robert S.; Hale, Zoe M.; Levine, Myron M.; Lowe, C. R.; Payne, Frank P.

    1994-07-01

    An evanescent wave immunoassay for cholera antitoxin immunoglobulins was performed using a single mode tapered optical fiber loop sensor. The transducer was silanized with 3- glycidoxypropyltrimethoxysilane and chemically modified to link covalently either cholera toxin B subunit or a synthetic peptide derived from it, CTP3. The sensor was exposed to seral fluids, obtained from human volunteers having been exposed to live virulent Vibrio cholerae 01 and shown to produce rice-water stools. Other toxins of interest, such as Clostridium botulinum toxin A, have been tested on similar systems. The bound unlabelled immunoglobulins were then exposed to a mixture of FITC-anti-IgG and TRITC-anti-IgA, without requirement for a separation step. The emanating fluorescent emissions of fluorescein and rhodamine, excited by the input laser light, were coupled back into the guided mode of the tapered fiber, and used to determine the concentrations of the complementary antigens.

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

    Directory of Open Access Journals (Sweden)

    Ramadhan Hashim

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

  12. G-P boosts steam load on hog fuel boilers while reducing particulates

    Energy Technology Data Exchange (ETDEWEB)

    Guidon, M.W.

    1980-11-01

    It is stated that baghouse installation permits generation of 56,000 more lb of steam per hour from three hog fuel boilers at Georgia Pacific's Bellingham mill, recovering 10,000,000 Btu/hour. In addition, fuel oil savings of 260 bbl/day were achieved and particulate emissions were reduced to 0.018 grains/std. dry cubic feet at 12% CO/sub 2/ with near zero opacity.

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

    Science.gov (United States)

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

    1994-10-01

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

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

    Science.gov (United States)

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

    2014-10-01

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

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

    OpenAIRE

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

    2014-01-01

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

  16. Technical and environmental efifciency of hog production in China-A stochastic frontier production function analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ying-heng; ZHANG Xiao-heng; TIAN Xu; GENG Xian-hui; ZHANG Peng; YAN Bin-jian

    2015-01-01

    This article analyses the technical and environmental efifciency of hog production in China using data from the China Agricultural Product Cost-Beneift Compilation (NDRC 2005–2013) and the First National Census of Pol ution:Manual of Discharge Coefifcient of Livestock and Poultry Industry (IEDA and NIES 2009). The empirical results show a great variation in environmental efifciency, ranging from 0.344 to 0.973 with a mean value of 0.672 that declines over time. Southwest China is found to be the most environmental y efifcient region, while the Northeast and the Northwest are the least efifcient. Another ifnding is that technical and environmental efifciencies are highly correlated in hog production;the most environ-mental y efifcient regions are usual y found to have high technical efifciency, and vice versa. In addition, we computed the output elasticities with respect to each factor input. The results show that feed is the most efifcient input, with an output elasticity of approximately 0.551, which is much higher than the elasticity of the nitrogen surplus, other capital or labour. The output elasticity with respect to the nitrogen surplus is 0.287 on average. Final y, the scale elasticity in hog production is slightly higher than 1.

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

    Directory of Open Access Journals (Sweden)

    Valeru Soni P

    2012-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2013-07-16

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

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

    OpenAIRE

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

    2013-01-01

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

  1. 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.

  2. Cholera outbreaks in the classical biotype era.

    Science.gov (United States)

    Siddique, A K; Cash, Richard

    2014-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

  5. An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006–2015 data for China’s 22 provinces

    Science.gov (United States)

    Pang, Jinbo; Deng, Lingfei

    2017-01-01

    Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a “buy” strategy and speculators adopt a “do not speculate” strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies. PMID:28241024

  6. An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006-2015 data for China's 22 provinces.

    Science.gov (United States)

    Pang, Jinbo; Deng, Lingfei; Wang, Gangyi

    2017-01-01

    Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a "buy" strategy and speculators adopt a "do not speculate" strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies.

  7. 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

  8. The burden of cholera in Uganda.

    Directory of Open Access Journals (Sweden)

    Godfrey Bwire

    Full Text Available 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

  9. The Vibrio cholerae Type VI Secretion System: Evaluating Its Role in the Human Disease Cholera

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    Sarah T. Miyata

    2010-11-01

    Full Text Available Vibrio cholerae, the marine bacterium responsible for the diarrheal disease cholera, utilizes a multitude of virulence factors to cause disease. The importance of two of these factors, the toxin co-regulated pilus (TCP and cholera toxin (CT, has been well documented for pandemic O1 and epidemic O139 serogroups. In contrast, endemic non-O1 and non-O139 serogroups can cause localized outbreaks of cholera-like illness, often in the absence of TCP and CT. One virulence mechanism used by these strains is the type VI secretion system (T6SS to export toxins across the cell envelope and confer toxicity towards eukaryotic and prokaryotic organisms. The V. cholerae strain V52 (an O37 serogroup strain possesses a constitutively active T6SS and was responsible for an outbreak of gastroenteritis in Sudan in 1968. To evaluate a potential role of the T6SS in the disease cholera, we compared the T6SS clusters of V. cholerae strains with sequenced genomes. We found that the majority of V. cholerae strains, including one pandemic strain, contain intact T6SS gene clusters; thus, we propose that the T6SS is a conserved mechanism that allows pandemic and endemic V. cholerae to persist both in the host and in the environment.

  10. 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.

  11. Biosensing Vibrio cholerae with Genetically Engineered Escherichia coli.

    Science.gov (United States)

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

    2016-11-18

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

  12. Understanding the Cholera Epidemic, Haiti

    Science.gov (United States)

    Barrais, Robert; Faucher, Benoît; Haus, Rachel; Piarroux, Martine; Gaudart, Jean; Magloire, Roc; Raoult, Didier

    2011-01-01

    After onset of a cholera epidemic in Haiti in mid-October 2010, a team of researchers from France and Haiti implemented field investigations and built a database of daily cases to facilitate identification of communes most affected. Several models were used to identify spatiotemporal clusters, assess relative risk associated with the epidemic’s spread, and investigate causes of its rapid expansion in Artibonite Department. Spatiotemporal analyses highlighted 5 significant clusters (p<0.001): 1 near Mirebalais (October 16–19) next to a United Nations camp with deficient sanitation, 1 along the Artibonite River (October 20–28), and 3 caused by the centrifugal epidemic spread during November. The regression model indicated that cholera more severely affected communes in the coastal plain (risk ratio 4.91) along the Artibonite River downstream of Mirebalais (risk ratio 4.60). Our findings strongly suggest that contamination of the Artibonite and 1 of its tributaries downstream from a military camp triggered the epidemic. PMID:21762567

  13. Metabolic respiration induces AMPK- and Ire1p-dependent activation of the p38-Type HOG MAPK pathway.

    Science.gov (United States)

    Adhikari, Hema; Cullen, Paul J

    2014-10-01

    Evolutionarily conserved mitogen activated protein kinase (MAPK) pathways regulate the response to stress as well as cell differentiation. In Saccharomyces cerevisiae, growth in non-preferred carbon sources (like galactose) induces differentiation to the filamentous cell type through an extracellular-signal regulated kinase (ERK)-type MAPK pathway. The filamentous growth MAPK pathway shares components with a p38-type High Osmolarity Glycerol response (HOG) pathway, which regulates the response to changes in osmolarity. To determine the extent of functional overlap between the MAPK pathways, comparative RNA sequencing was performed, which uncovered an unexpected role for the HOG pathway in regulating the response to growth in galactose. The HOG pathway was induced during growth in galactose, which required the nutrient regulatory AMP-dependent protein kinase (AMPK) Snf1p, an intact respiratory chain, and a functional tricarboxylic acid (TCA) cycle. The unfolded protein response (UPR) kinase Ire1p was also required for HOG pathway activation in this context. Thus, the filamentous growth and HOG pathways are both active during growth in galactose. The two pathways redundantly promoted growth in galactose, but paradoxically, they also inhibited each other's activities. Such cross-modulation was critical to optimize the differentiation response. The human fungal pathogen Candida albicans showed a similar regulatory circuit. Thus, an evolutionarily conserved regulatory axis links metabolic respiration and AMPK to Ire1p, which regulates a differentiation response involving the modulated activity of ERK and p38 MAPK pathways.

  14. Metabolic respiration induces AMPK- and Ire1p-dependent activation of the p38-Type HOG MAPK pathway.

    Directory of Open Access Journals (Sweden)

    Hema Adhikari

    2014-10-01

    Full Text Available Evolutionarily conserved mitogen activated protein kinase (MAPK pathways regulate the response to stress as well as cell differentiation. In Saccharomyces cerevisiae, growth in non-preferred carbon sources (like galactose induces differentiation to the filamentous cell type through an extracellular-signal regulated kinase (ERK-type MAPK pathway. The filamentous growth MAPK pathway shares components with a p38-type High Osmolarity Glycerol response (HOG pathway, which regulates the response to changes in osmolarity. To determine the extent of functional overlap between the MAPK pathways, comparative RNA sequencing was performed, which uncovered an unexpected role for the HOG pathway in regulating the response to growth in galactose. The HOG pathway was induced during growth in galactose, which required the nutrient regulatory AMP-dependent protein kinase (AMPK Snf1p, an intact respiratory chain, and a functional tricarboxylic acid (TCA cycle. The unfolded protein response (UPR kinase Ire1p was also required for HOG pathway activation in this context. Thus, the filamentous growth and HOG pathways are both active during growth in galactose. The two pathways redundantly promoted growth in galactose, but paradoxically, they also inhibited each other's activities. Such cross-modulation was critical to optimize the differentiation response. The human fungal pathogen Candida albicans showed a similar regulatory circuit. Thus, an evolutionarily conserved regulatory axis links metabolic respiration and AMPK to Ire1p, which regulates a differentiation response involving the modulated activity of ERK and p38 MAPK pathways.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Raisa Rafique

    2016-10-01

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

  18. Immunizing Canada geese against avian cholera

    Science.gov (United States)

    Price, J.I.

    1985-01-01

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

  19. Pursuing Justice in Haiti's Cholera Epidemic.

    Science.gov (United States)

    Weinmeyer, Richard

    2016-07-01

    In 2010, the nation of Haiti was leveled by a shattering earthquake that killed thousands and devastated its already fragile infrastructure. During relief efforts to aid Haiti's suffering population, the United Nations sent troops to Haiti to assist the rebuilding of country's most basic services. But those troops unknowingly carried with them the bacteria that cause cholera, and through the UN's negligent actions, it triggered a horrifying cholera epidemic that continues to harm the Haitian people. Those injured by the cholera epidemic have sought relief in the US federal court system to obtain justice for those killed or sickened by the cholera outbreak. The UN has declared legal immunity for causing the epidemic, yet the litigation on this matter is ongoing. © 2016 American Medical Association. All Rights Reserved. ISSN 2376-6980.

  20. Intestinal Colonization Dynamics of Vibrio cholerae

    Science.gov (United States)

    Almagro-Moreno, Salvador; Pruss, Kali; Taylor, Ronald K.

    2015-01-01

    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. PMID:25996593

  1. 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.

  2. On spatially explicit models of cholera epidemics

    National Research Council Canada - National Science Library

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

    2010-01-01

    We generalize a recently proposed model for cholera epidemics that accounts for local communities of susceptibles and infectives in a spatially explicit arrangement of nodes linked by networks having...

  3. [Five years of cholera surveillance in Ivory Coast during social and political crisis, 2001 to 2005].

    Science.gov (United States)

    Ekra, K D; Attoh-Touré, H; Bénié, B V J; Coulibaly, D; Koutouan, M G; Aka, L N; Dagnan, S N; Coulibaly, A; Douba, A; Tiembré, I; Odéhouri-Koudou, P; Tagliante-Saracino, J

    2009-05-01

    For an efficient struggle against infectious diseases with epidemic potential, the Cdte d'Ivoire set up a precocious alert system in 2001 with a main objective: to detect epidemics of cholera, measles, yellow fever and meningitis and to provide necessary information for their control and their prevention. During the 2001 to 2005 period, the country was marked by military and political crisis which occurred in 2002; the country had to face up to a reappearance of cholera. How did it evolve in such a context? The question was to describe the performances of the system and the evolution of cholera from weekly data collected by the centers of epidemiological monitoring in health districts. The cases and declared deaths were compiled and the indicators of morbidity and mortality were then studied according to time site and individual features on the period of 2001 to 2005. From 2001 to 2005, 11,874 cases were notified with 564 deaths and a lethal rate of 4.7%. In 2001, from the initial source of infection, the civil jail, the epidemic of cholera disseminated itself through visitors in the whole city of Abidjan where 3250 cases were notified. Out of city, 20 outbreaks have been declared with a total of 3010 cases. The yearly highest impact, 37 living cases/100,000 inhabitants recorded in 2001, decreased regularly until 2005 with 0.2 living cases/100,000. After 2002, outbreaks were located mainly in the half south of the country which welcomed displaced populations from the north, preferably in transition or settling zones near the front line. The lethal rate in Abidjan (2.3%) was less important than that of other health districts (8.6%). The lethal rate globally increased as the impact decreased. Vibrio cholerae was responsible for the epidemics. The group of 15 years old and over was the most affected (12.69 living cases/100,000) whereas the highest lethal rate appeared in the group under 5 years old (6.6%). The reappearance and constant cholera epidemics in Côte d

  4. Re-emergence of Cholera Vaccine.

    Science.gov (United States)

    Berger; Shapiro

    1997-06-01

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

  5. Influence of human behavior on cholera dynamics

    OpenAIRE

    Wang, Xueying; Gao, Daozhou; Wang, Jin

    2015-01-01

    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 equa...

  6. FOWL CHOLERA IN A BREEDER FLOCK

    Directory of Open Access Journals (Sweden)

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

    2003-12-01

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

  7. Performance of the constructed wetland systems in pollutants removal from hog wastewater

    OpenAIRE

    Wallison da Silva Freitas; Paola Alfonsa Vieira Lo Monaco; Antonio Teixeira de Matos

    2010-01-01

    The main objective of this work was to evaluate the efficiency of a constructed wetland systems (CWS) for pollutants removal, in mono crop and multi crop with three different species of plants, originated from hog wastewater treatment (HW). Therefore, 5 CWS of 24.0 m x 1.1 m x 0.7 m were constructed, sealed with a membrane of polyvinyl chloride (PVC) and filled with 0.4 m of small gravel. In CWS1, CWS2 and CWS3 grown to cattail (Typha latifolia L.), Alternanthera philoxeroides (Mart.) Griseb....

  8. 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

  9. [The history of cholera epidemics in Israel].

    Science.gov (United States)

    Schwartz, Eli; Bar-El, Dan; Schur, Natan

    2005-05-01

    During the years 1831-1918 Israel (Palestine at that time) suffered from repeated cholera epidemics. The cholera epidemics were the major cause of severe health crisis among the population. The epidemics were transmitted by returening pilgrims returning from Mecca and, during the first world War, by the Turkish soldiers crossing the country. The disease caused panic amongst the population due to its high mortality rate. Quarantine which was the major measure taken by the government at that time was repeatedly broken by people trying to escape from the affected area. During the epidemic of 1902, patients were even reluctant to be treated by physicians as they were blamed for causing death. On the other hand, cholera was a major trigger for maintaining a better sanitation and establishing social relief systems within the communities. Most of the epidemics occurred in the old cities such as Jerusalem, Tiberia and Jaffa where infrastructure was inadequate. Cholera outbreaks were the trigger to build outside the old cities as in case of Jerusalem in which after the 1865 outbreak the city was expanded outside the walls. Since the end of the Ottoman period in Israel, cholera epidemics ceased, and except for very small occeasional small outbreaks, cholera is not seen here more.

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

    Science.gov (United States)

    1991-04-01

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

  11. Potential for Controlling Cholera Using a Ring Vaccination Strategy: Re-analysis of Data from a Cluster-Randomized Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Mohammad Ali

    2016-09-01

    Full Text Available Vaccinating a buffer of individuals around a case (ring vaccination has the potential to target those who are at highest risk of infection, reducing the number of doses needed to control a disease. We explored the potential vaccine effectiveness (VE of oral cholera vaccines (OCVs for such a strategy.This analysis uses existing data from a cluster-randomized clinical trial in which OCV or placebo was given to 71,900 participants in Kolkata, India, from 27 July to 10 September 2006. Cholera surveillance was then conducted on 144,106 individuals living in the study area, including trial participants, for 5 y following vaccination. First, we explored the risk of cholera among contacts of cholera patients, and, second, we measured VE among individuals living within 25 m of cholera cases between 8 and 28 d after onset of the index case. For the first analysis, individuals living around each index case identified during the 5-y period were assembled using a ring to define cohorts of individuals exposed to cholera index cases. An index control without cholera was randomly selected for each index case from the same population, matched by age group, and individuals living around each index control were assembled using a ring to define cohorts not exposed to cholera cases. Cholera attack rates among the exposed and non-exposed cohorts were compared using different distances from the index case/control to define the rings and different time frames to define the period at risk. For the VE analysis, the exposed cohorts were further stratified according to the level of vaccine coverage into high and low coverage strata. Overall VE was assessed by comparing the attack rates between high and low vaccine coverage strata irrespective of individuals' vaccination status, and indirect VE was assessed by comparing the attack rates among unvaccinated members between high and low vaccine coverage strata. Cholera risk among the cohort exposed to cholera cases was 5

  12. Potential for Controlling Cholera Using a Ring Vaccination Strategy: Re-analysis of Data from a Cluster-Randomized Clinical Trial.

    Science.gov (United States)

    Ali, Mohammad; Debes, Amanda K; Luquero, Francisco J; Kim, Deok Ryun; Park, Je Yeon; Digilio, Laura; Manna, Byomkesh; Kanungo, Suman; Dutta, Shanta; Sur, Dipika; Bhattacharya, Sujit K; Sack, David A

    2016-09-01

    Vaccinating a buffer of individuals around a case (ring vaccination) has the potential to target those who are at highest risk of infection, reducing the number of doses needed to control a disease. We explored the potential vaccine effectiveness (VE) of oral cholera vaccines (OCVs) for such a strategy. This analysis uses existing data from a cluster-randomized clinical trial in which OCV or placebo was given to 71,900 participants in Kolkata, India, from 27 July to 10 September 2006. Cholera surveillance was then conducted on 144,106 individuals living in the study area, including trial participants, for 5 y following vaccination. First, we explored the risk of cholera among contacts of cholera patients, and, second, we measured VE among individuals living within 25 m of cholera cases between 8 and 28 d after onset of the index case. For the first analysis, individuals living around each index case identified during the 5-y period were assembled using a ring to define cohorts of individuals exposed to cholera index cases. An index control without cholera was randomly selected for each index case from the same population, matched by age group, and individuals living around each index control were assembled using a ring to define cohorts not exposed to cholera cases. Cholera attack rates among the exposed and non-exposed cohorts were compared using different distances from the index case/control to define the rings and different time frames to define the period at risk. For the VE analysis, the exposed cohorts were further stratified according to the level of vaccine coverage into high and low coverage strata. Overall VE was assessed by comparing the attack rates between high and low vaccine coverage strata irrespective of individuals' vaccination status, and indirect VE was assessed by comparing the attack rates among unvaccinated members between high and low vaccine coverage strata. Cholera risk among the cohort exposed to cholera cases was 5-11 times higher than

  13. Second-pandemic strain of Vibrio cholerae from the Philadelphia cholera outbreak of 1849.

    Science.gov (United States)

    Devault, Alison M; Golding, G Brian; Waglechner, Nicholas; Enk, Jacob M; Kuch, Melanie; Tien, Joseph H; Shi, Mang; Fisman, David N; Dhody, Anna N; Forrest, Stephen; Bos, Kirsten I; Earn, David J D; Holmes, Edward C; Poinar, Hendrik N

    2014-01-23

    In the 19th century, there were several major cholera pandemics in the Indian subcontinent, Europe, and North America. The causes of these outbreaks and the genomic strain identities remain a mystery. We used targeted high-throughput sequencing to reconstruct the Vibrio cholerae genome from the preserved intestine of a victim of the 1849 cholera outbreak in Philadelphia, part of the second cholera pandemic. This O1 biotype strain has 95 to 97% similarity with the classical O395 genome, differing by 203 single-nucleotide polymorphisms (SNPs), lacking three genomic islands, and probably having one or more tandem cholera toxin prophage (CTX) arrays, which potentially affected its virulence. This result highlights archived medical remains as a potential resource for investigations into the genomic origins of past pandemics.

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

    African Journals Online (AJOL)

    The case of cholera preparedness, response and prevention in the SADC region: ... need for alternative solutions, including a socio-political understanding of cholera responses at different levels of scale and at different stages of an outbreak.

  15. The erratic evolution of cholera therapy: from folklore to science.

    Science.gov (United States)

    Carpenter, C C

    1990-01-01

    Cholera is an exceptionally frightening epidemic disease because it kills its victims so very rapidly. The development of cholera therapy is traced from the early 19th century purges and bloodletting to the current use of oral rehydration solutions.

  16. Cholera Epidemiology in Zambia from 2000 to 2010: Implications for ...

    African Journals Online (AJOL)

    Cholera Epidemiology in Zambia from 2000 to 2010: Implications for ... we make recommendations for improving cholera prevention and control in country. ... compared to 2003) and 115 deaths (CFR 1.6%) of the disease were reported with ...

  17. antimicrobial susceptibility pattern of vibrio cholerae 01 strains ...

    African Journals Online (AJOL)

    hi-tech

    2000-07-07

    Jul 7, 2000 ... of cholera patients, however, patients with severe disease require antibiotic treatment to reduce the duration of illness and reduce replacement fluid ... Spread of cholera epidemics worldwide has been associated with the ...

  18. 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

  19. Catechol Siderophore Transport by Vibrio cholerae.

    Science.gov (United States)

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

    2015-09-01

    Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses the catechol siderophore vibriobactin and also uses siderophores secreted by other species, including enterobactin produced by Escherichia coli. E. coli secretes both canonical cyclic enterobactin and linear enterobactin derivatives likely derived from its cleavage by the enterobactin esterase Fes. We show here that V. cholerae does not use cyclic enterobactin but instead uses its linear derivatives. V. cholerae lacked both a receptor for efficient transport of cyclic enterobactin and enterobactin esterase to promote removal of iron from the ferrisiderophore complex. To further characterize the transport of catechol siderophores, we show that the linear enterobactin derivatives were transported into V. cholerae by either of the catechol siderophore receptors IrgA and VctA, which also transported the synthetic siderophore MECAM [1,3,5-N,N',N″-tris-(2,3-dihydroxybenzoyl)-triaminomethylbenzene]. Vibriobactin is transported via the additional catechol siderophore receptor ViuA, while the Vibrio fluvialis siderophore fluvibactin was transported by all three catechol receptors. ViuB, a putative V. cholerae siderophore-interacting protein (SIP), functionally substituted for the E. coli ferric reductase YqjH, which promotes the release of iron from the siderophore in the bacterial cytoplasm. In V. cholerae, ViuB was required for the use of vibriobactin but was not required for the use of MECAM, fluvibactin, ferrichrome, or the linear derivatives of enterobactin. This suggests the presence of another protein in V. cholerae capable of promoting the release of iron from these siderophores. Vibrio cholerae is a major human pathogen and also serves as a model for the Vibrionaceae, which include other serious human and fish pathogens. The ability of these species to persist and acquire essential

  20. Catechol Siderophore Transport by Vibrio cholerae

    Science.gov (United States)

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

    2015-01-01

    ABSTRACT Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses the catechol siderophore vibriobactin and also uses siderophores secreted by other species, including enterobactin produced by Escherichia coli. E. coli secretes both canonical cyclic enterobactin and linear enterobactin derivatives likely derived from its cleavage by the enterobactin esterase Fes. We show here that V. cholerae does not use cyclic enterobactin but instead uses its linear derivatives. V. cholerae lacked both a receptor for efficient transport of cyclic enterobactin and enterobactin esterase to promote removal of iron from the ferrisiderophore complex. To further characterize the transport of catechol siderophores, we show that the linear enterobactin derivatives were transported into V. cholerae by either of the catechol siderophore receptors IrgA and VctA, which also transported the synthetic siderophore MECAM [1,3,5-N,N′,N″-tris-(2,3-dihydroxybenzoyl)-triaminomethylbenzene]. Vibriobactin is transported via the additional catechol siderophore receptor ViuA, while the Vibrio fluvialis siderophore fluvibactin was transported by all three catechol receptors. ViuB, a putative V. cholerae siderophore-interacting protein (SIP), functionally substituted for the E. coli ferric reductase YqjH, which promotes the release of iron from the siderophore in the bacterial cytoplasm. In V. cholerae, ViuB was required for the use of vibriobactin but was not required for the use of MECAM, fluvibactin, ferrichrome, or the linear derivatives of enterobactin. This suggests the presence of another protein in V. cholerae capable of promoting the release of iron from these siderophores. IMPORTANCE Vibrio cholerae is a major human pathogen and also serves as a model for the Vibrionaceae, which include other serious human and fish pathogens. The ability of these species to persist and

  1. 5-hydroxytryptamine release into human jejunum by cholera toxin.

    OpenAIRE

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

    1996-01-01

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

  2. Control and Intervention of Cholera Outbreaks in Refugee Camps

    OpenAIRE

    Sim, Christianna

    2013-01-01

    Cholera, a disease with a long history, continues to devastate populations around the world. Due to the route of transmission of Vibrio cholerae, the bacterial pathogen that causes the disease, cholera only seems to affect developing countries, giving rise to a health disparity. For developed countries with adequate water and sewage treatment systems, the threat of cholera is irrelevant. Meanwhile, developing countries which have underlying vulnerabilities of poverty and lack basic access to ...

  3. Biophysical properties of Saccharomyces cerevisiae and their relationship with HOG pathway activation.

    Science.gov (United States)

    Schaber, Jörg; Adrover, Miquel Angel; Eriksson, Emma; Pelet, Serge; Petelenz-Kurdziel, Elzbieta; Klein, Dagmara; Posas, Francesc; Goksör, Mattias; Peter, Mathias; Hohmann, Stefan; Klipp, Edda

    2010-10-01

    Parameterized models of biophysical and mechanical cell properties are important for predictive mathematical modeling of cellular processes. The concepts of turgor, cell wall elasticity, osmotically active volume, and intracellular osmolarity have been investigated for decades, but a consistent rigorous parameterization of these concepts is lacking. Here, we subjected several data sets of minimum volume measurements in yeast obtained after hyper-osmotic shock to a thermodynamic modeling framework. We estimated parameters for several relevant biophysical cell properties and tested alternative hypotheses about these concepts using a model discrimination approach. In accordance with previous reports, we estimated an average initial turgor of 0.6 ± 0.2 MPa and found that turgor becomes negligible at a relative volume of 93.3 ± 6.3% corresponding to an osmotic shock of 0.4 ± 0.2 Osm/l. At high stress levels (4 Osm/l), plasmolysis may occur. We found that the volumetric elastic modulus, a measure of cell wall elasticity, is 14.3 ± 10.4 MPa. Our model discrimination analysis suggests that other thermodynamic quantities affecting the intracellular water potential, for example the matrix potential, can be neglected under physiological conditions. The parameterized turgor models showed that activation of the osmosensing high osmolarity glycerol (HOG) signaling pathway correlates with turgor loss in a 1:1 relationship. This finding suggests that mechanical properties of the membrane trigger HOG pathway activation, which can be represented and quantitatively modeled by turgor.

  4. A novel technique for hydrogen production from hog-manure in supercritical partial oxidation (SCWPO)

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Emhemmed A.; Charpentier, Paul [Western Ontario Univ., London, ON (Canada). Dept. of Chemical and Biochemical Engineering; Nakhla, George [Western Ontario Univ., London, ON (Canada). Dept. of Chemical and Biochemical Engineering; Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering; Elbeshbishy, Elsayed; Hafez, Hisham [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering

    2010-07-01

    In this study, the catalytic hydrogen production from hog manure using supercritical water partial oxidation was investigated in a batch reactor at a temperature of 500 C, and pressure of 28 MPa using several metallic catalysts. Hog manure was characterized by a total and soluble chemical oxygen demand (TCOD, SCOD) of 57000 and 28000 mg/L, total and volatile suspended solids (TSS, VSS) of 25000, 19000, and ammonia of 2400 mg/L, respectively. The order of H{sub 2} production was the following: Pd/AC > Ru/Al{sub 2}O{sub 3} > Ru/AC > AC > NaOH. The order of COD reduction efficiency was as follows: NaOH > Ru/AC > AC > Ru/Al{sub 2}O{sub 3} > Pd/AC. The behaviour of the volatile fatty acids (VFA's), ethanol, methanol, ammonia, H{sub 2}S, and Sulfate was investigated experimentally and discussed. A 35 % reduction in the H{sub 2} and CH{sub 4} yields was observed in the sequential gasification partial oxidation (oxidant at an 80 % of theoretical requirement) experiments compared to the gasification experiments (catalyst only). Moreover, this reduction in gas yields was coincided with a 45 % reduction in the liquid effluent chemical oxygen demand (COD), 60 % reduction of the ammonia concentration in the liquid effluent, and 20 % reduction in the H{sub 2}S concentration in the effluent gas. (orig.)

  5. Avian cholera in Nebraska's Rainwater Basin

    Science.gov (United States)

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

    1984-01-01

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

  6. Cholera risk factors, Papua New Guinea, 2010

    Directory of Open Access Journals (Sweden)

    Rosewell Alexander

    2012-11-01

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

  7. Whole-Genome Sequences of 26 Vibrio cholerae Isolates

    Science.gov (United States)

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

    2016-01-01

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

  8. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Science.gov (United States)

    2010-04-01

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

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

    African Journals Online (AJOL)

    2013-08-20

    Aug 20, 2013 ... The detection sensitivity of the multiplex PCR was 1.9 x 103 V. cholerae per PCR reaction. A ... Moreover, biochemical identification systems ..... Lane 2: V. cholerae O1 ATCC 14033; Lane 3: V. cholerae O139 ATCC 51394;.

  10. Response to the cholera outbreak in South Sudan

    African Journals Online (AJOL)

    As we go to press, the cholera has spread to other parts of the country and the cases are ... Cholera is a disease of poor sanitation and hygiene, with a short incubation ... Cholera Treatment Centers (CTC) have been set up in Juba Teaching ...

  11. Antibody-Secreting Cell Responses after Vibrio cholerae O1 Infection and Oral Cholera Vaccination in Adults in Bangladesh

    OpenAIRE

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

    2013-01-01

    Infection with Vibrio cholerae and oral cholera vaccines (OCVs) induce transient circulating plasmablast responses that peak within approximately 7 days after infection or vaccination. We previously demonstrated that plasmablast responses strongly correlate with subsequent levels of V. cholerae-specific duodenal antibodies up to 6 months after V. cholerae infection. Hence, plasmablast responses provide an early window into the immunologic memory at the mucosal surface. In this study, we chara...

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

    OpenAIRE

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

    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...

  13. 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

  14. 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.

  15. 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.

  16. Role of Shrimp Chitin in the Ecology of Toxigenic Vibrio cholerae and Cholera Transmission

    Directory of Open Access Journals (Sweden)

    Marzia eSultana

    2012-01-01

    Full Text Available Seasonal plankton blooms correlate with occurrence of cholera in Bangladesh, although the mechanism of how dormant Vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. In this study, laboratory microcosms prepared with estuarine Mathbaria water (MW samples supported active growth of toxigenic V. cholerae O1 up to seven weeks as opposed to six months when microcosms were supplemented with dehydrated shrimp chitin chips (CC as the single source of nutrient. Bacterial counting and detection of wbe and ctxA genes were done employing culture, Direct Fluorescent Antibody (DFA assay, and multiplex PCR (M-PCR methods. In MW microcosm, the aqueous phase became clear as the non-culturable cells settled, whereas the aqueous phase of the MW-CC microcosm became turbid from bacterial growth stimulated by chitin. Bacterial chitin degradation and biofilm formation proceeded from an initial steady state to a gradually declining bacterial culturable count. V. cholerae within the microenvironments of chitin and chitin-associated biofilms remained metabolically active even in a high acidic environment without losing either viability or virulence. It is concluded that the abundance of chitin that occurs during blooms plays an important role in the aquatic life cycle of V. cholerae and, ultimately, in the seasonal transmission of cholera.

  17. Nepalese origin of cholera epidemic in Haiti.

    Science.gov (United States)

    Frerichs, R R; Keim, P S; Barrais, R; Piarroux, R

    2012-06-01

    Cholera appeared in Haiti in October 2010 for the first time in recorded history. The causative agent was quickly identified by the Haitian National Public Health Laboratory and the United States Centers for Disease Control and Prevention as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Since then, >500 000 government-acknowledged cholera cases and >7000 deaths have occurred, the largest cholera epidemic in the world, with the real death toll probably much higher. Questions of origin have been widely debated with some attributing the onset of the epidemic to climatic factors and others to human transmission. None of the evidence on origin supports climatic factors. Instead, recent epidemiological and molecular-genetic evidence point to the United Nations peacekeeping troops from Nepal as the source of cholera to Haiti, following their troop rotation in early October 2010. Such findings have important policy implications for shaping future international relief efforts. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  18. Resurgence of cholera in Hong Kong.

    Science.gov (United States)

    Lee, S H; Lai, S T; Lai, J Y; Leung, N K

    1996-08-01

    Cholera is one of the three diseases subject to the International Health Regulations. After a period of over 30 years, the seventh pandemic of cholera, which started in South East Asia in 1961, still shows no sign of a decline. On the contrary, it has increased its severity and invaded many other countries in Africa and Latin America. In the last two years, there has been a recrudescence of the disease in South East Asia and Western Pacific Regions. The discovery of a new strain of Vibrio cholerae 0139 in these regions is causing concern in view of its potential to cause major epidemics and higher mortality. Hong Kong had two intensive outbreaks of cholera in the last two years. The cause of these outbreaks was not clear, but adverse environmental conditions and increasing pollution of coastal waters have been implicated. The spread of cholera knows no geographical boundaries. There is a need for intensified efforts among health authorities in the affected areas to prevent the international spread of the disease.

  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. 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.

  1. "Profits to the Danes, for Us--Hog Stench?" The Campaign against Danish Swine CAFOs in Rural Lithuania

    Science.gov (United States)

    Juska, Arunas

    2010-01-01

    The paper analyzes a grass-roots campaign to limit the expansion of Danish-owned industrial hog operator Saerimner in Lithuania. The industrialization of livestock production as well as local responses to the restructuring of meat production are interpreted within the broader context of the incorporation of peripheral regions into global agro-food…

  2. SAR Target Recognition via Supervised Discriminative Dictionary Learning and Sparse Representation of the SAR-HOG Feature

    Directory of Open Access Journals (Sweden)

    Shengli Song

    2016-08-01

    Full Text Available Automatic target recognition (ATR in synthetic aperture radar (SAR images plays an important role in both national defense and civil applications. Although many methods have been proposed, SAR ATR is still very challenging due to the complex application environment. Feature extraction and classification are key points in SAR ATR. In this paper, we first design a novel feature, which is a histogram of oriented gradients (HOG-like feature for SAR ATR (called SAR-HOG. Then, we propose a supervised discriminative dictionary learning (SDDL method to learn a discriminative dictionary for SAR ATR and propose a strategy to simplify the optimization problem. Finally, we propose a SAR ATR classifier based on SDDL and sparse representation (called SDDLSR, in which both the reconstruction error and the classification error are considered. Extensive experiments are performed on the MSTAR database under standard operating conditions and extended operating conditions. The experimental results show that SAR-HOG can reliably capture the structures of targets in SAR images, and SDDL can further capture subtle differences among the different classes. By virtue of the SAR-HOG feature and SDDLSR, the proposed method achieves the state-of-the-art performance on MSTAR database. Especially for the extended operating conditions (EOC scenario “Training 17 ∘ —Testing 45 ∘ ”, the proposed method improves remarkably with respect to the previous works.

  3. MAPK Hog1 closes the S. cerevisiae glycerol channel Fps1 by phosphorylating and displacing its positive regulators

    Science.gov (United States)

    Lee, Jongmin; Reiter, Wolfgang; Dohnal, Ilse; Gregori, Christa; Beese-Sims, Sara; Kuchler, Karl; Ammerer, Gustav; Levin, David E.

    2013-01-01

    The aquaglyceroprin Fps1 is responsible for glycerol transport in yeast in response to changes in extracellular osmolarity. Control of Fps1 channel activity in response to hyperosmotic shock involves a redundant pair of regulators, Rgc1 (regulator of the glycerol channel 1) and Rgc2, and the MAPK Hog1 (high-osmolarity glycerol response 1). However, the mechanism by which these factors influence channel activity is unknown. We show that Rgc2 maintains Fps1 in the open channel state in the absence of osmotic stress by binding to its C-terminal cytoplasmic domain. This interaction involves a tripartite pleckstrin homology (PH) domain within Rgc2 and a partial PH domain within Fps1. Activation of Hog1 in response to hyperosmotic shock induces the rapid eviction of Rgc2 from Fps1 and consequent channel closure. Hog1 was recruited to the N-terminal cytoplasmic domain of Fps1, which it uses as a platform from which to multiply phosphorylate Rgc2. Thus, these results reveal the mechanism by which Hog1 regulates Fps1 in response to hyperosmotic shock. PMID:24298058

  4. Persistence of Escherichia coli and Salmonella in surface soil following application of liquid hog manure for production of pickling cucumbers.

    Science.gov (United States)

    Côté, Caroline; Quessy, Sylvain

    2005-05-01

    Liquid hog manure is routinely applied to farm land as a crop fertilizer. However, this practice raises food safety concerns, especially when manure is used on fruit and vegetable crops. The objectives of this project were to evaluate the persistence of Escherichia coli and Salmonella in surface soil after application of liquid hog manure to fields where pickling cucumbers were grown and to verify the microbiological quality of harvested cucumbers. Mineral fertilizers were replaced by liquid hog manure at various ratios in the production of pickling cucumbers in a 3-year field study. The experimental design was a randomized complete block comprising four replicates in sandy loam (years 1, 2, and 3) and loamy sand (year 3). Soil samples were taken at a depth of 20 cm every 2 weeks after June application of organic and inorganic fertilizers. Vegetable samples were also taken at harvest time. Liquid hog manure, soil, and vegetable (washed and unwashed) samples were analyzed for the presence of Salmonella and E. coli. An exponential decrease of E. coli populations was observed in surface soil after the application of manure. The estimated average time required to reach undetectable concentrations of E. coli in sandy loam varied from 56 to 70 days, whereas the absence of E. coli was estimated at 77 days in loamy sand. The maximal Salmonella persistence in soil was 54 days. E. coli and Salmonella were not detected in any vegetable samples.

  5. Differential gene expression and Hog1 interaction with osmoresponsive genes in the extremely halotolerant black yeast Hortaea werneckii

    Directory of Open Access Journals (Sweden)

    Plemenitaš Ana

    2007-08-01

    Full Text Available Abstract Background Fluctuations in external salinity force eukaryotic cells to respond by changes in the gene expression of proteins acting in protective biochemical processes, thus counteracting the changing osmotic pressure. The high-osmolarity glycerol (HOG signaling pathway is essential for the efficient up-regulation of the osmoresponsive genes. In this study, the differential gene expression of the extremely halotolerant black yeast Hortaea werneckii was explored. Furthermore, the interaction of mitogen-activated protein kinase HwHog1 and RNA polymerase II with the chromatin in cells adapted to an extremely hypersaline environment was analyzed. Results A cDNA subtraction library was constructed for H. werneckii, adapted to moderate salinity or an extremely hypersaline environment of 4.5 M NaCl. An uncommon osmoresponsive set of 95 differentially expressed genes was identified. The majority of these had not previously been connected with the adaptation of salt-sensitive S. cerevisiae to hypersaline conditions. The transcriptional response in hypersaline-adapted and hypersaline-stressed cells showed that only a subset of the identified genes responded to acute salt-stress, whereas all were differentially expressed in adapted cells. Interaction with HwHog1 was shown for 36 of the 95 differentially expressed genes. The majority of the identified osmoresponsive and HwHog1-dependent genes in H. werneckii have not been previously reported as Hog1-dependent genes in the salt-sensitive S. cerevisiae. The study further demonstrated the co-occupancy of HwHog1 and RNA polymerase II on the chromatin of 17 up-regulated and 2 down-regulated genes in 4.5 M NaCl-adapted H. werneckii cells. Conclusion Extremely halotolerant H. werneckii represents a suitable and highly relevant organism to study cellular responses to environmental salinity. In comparison with the salt-sensitive S. cerevisiae, this yeast shows a different set of genes being expressed at

  6. 改进的HOG和Gabor,LBP性能比较%Performance Comparison of Improved HOG,Gabor and LBP

    Institute of Scientific and Technical Information of China (English)

    向征; 谭恒良; 马争鸣

    2012-01-01

    为了实现复杂环境下的人脸特征有效表达,提出一种改进的梯度方向直方图(HOG)人脸识别方法.首先以人脸图像网格作为采样窗口并在其上提取HOG特征;然后将所有网格HOG特征向量进行组合,实现整个人脸特征表达;最后采用最近邻分类器进行识别.另外,比较了该方法与Gabor小波和局部二值模式(LBP)2种著名的人脸局部特征表示方法的优劣.实验结果表明,在调优的HOG参数下,在具有光照和时间环境等复杂变化的FERET人脸库中,较少维数的HOG特征比LBP特征有更好的表现,而且HOG特征提取时间和特征向量维数比Gabor小波方法更具有优势.%In order to achieve effective expression of the facial features in complex environment, an improved face recognition method of histograms of oriented gradients (HOG) is proposed. Firstly the face image grid is set as a sampling window, in which HOG features are extracted. Then all grid HOG feature vectors are composed to realize the whole facial features expression. Finally, recognition is achieved with a nearest neighbor classifier. We further compare it with two popular face local features expression methods, Gabor wavelet and local binary pattern (LBP). With the optimistic HOG parameters, experimental results show that HOG features with less dimensions have better performance than the LBP features in the FERET face collection under complex changes of light and time environments. Meanwhile HOG features have advantages over Gabor wavelet with less computational time of feature extraction and smaller number of feature vector dimensions.

  7. Hybrid Vibrio cholerae El Tor Lacking SXT Identified as the Cause of a Cholera Outbreak in the Philippines

    Science.gov (United States)

    Klinzing, David C.; Choi, Seon Young; Hasan, Nur A.; Matias, Ronald R.; Tayag, Enrique; Geronimo, Josefina; Skowronski, Evan; Rashed, Shah M.; Kawashima, Kent; Rosenzweig, C. Nicole; Gibbons, Henry S.; Torres, Brian C.; Liles, Veni; Alfon, Alicia C.; Juan, Maria Luisa; Natividad, Filipinas F.; Cebula, Thomas A.

    2015-01-01

    ABSTRACT Cholera continues to be a global threat, with high rates of morbidity and mortality. In 2011, a cholera outbreak occurred in Palawan, Philippines, affecting more than 500 people, and 20 individuals died. Vibrio cholerae O1 was confirmed as the etiological agent. Source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. In this study, three V. cholerae O1 isolates from a Philippines cholera outbreak were sequenced and their genomes analyzed to determine phylogenetic relatedness to V. cholerae O1 isolates from recent outbreaks of cholera elsewhere. The Philippines V. cholerae O1 isolates were determined to be V. cholerae O1 hybrid El Tor belonging to the seventh-pandemic clade. They clustered tightly, forming a monophyletic clade closely related to V. cholerae O1 hybrid El Tor from Asia and Africa. The isolates possess a unique multilocus variable-number tandem repeat analysis (MLVA) genotype (12-7-9-18-25 and 12-7-10-14-21) and lack SXT. In addition, they possess a novel 15-kb genomic island (GI-119) containing a predicted type I restriction-modification system. The CTXΦ-RS1 array of the Philippines isolates was similar to that of V. cholerae O1 MG116926, a hybrid El Tor strain isolated in Bangladesh in 1991. Overall, the data indicate that the Philippines V. cholerae O1 isolates are unique, differing from recent V. cholerae O1 isolates from Asia, Africa, and Haiti. Furthermore, the results of this study support the hypothesis that the Philippines isolates of V. cholerae O1 are indigenous and exist locally in the aquatic ecosystem of the Philippines. PMID:25900650

  8. 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.

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

    OpenAIRE

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

  11. Vibrio cholerae: A historical perspective and current trend

    Directory of Open Access Journals (Sweden)

    Mary Oyenike Oladokun

    2016-11-01

    Full Text Available Vibrio cholerae (V. cholerae is a Gram-negative, curved, rod-shaped bacteria with two of its strains V. cholerae O1 and V. cholerae O139 known to cause cholera, a deadly diarrheal disease that has repeatedly plagued the world in pandemics since 1817 and still remains a public health problem globally till today. The pathogens’ persistence in aquatic milieux during inter-epidemic periods is facilitated by the production of a biofilm, thus evolving from being an infection of oral-fecal transmission to a more composite ecological framework of a communicable disease. The outbreaks of cholera spread rapidly in various intensities within and among countries and even continents and the World Health Organization estimates that 3–5 million cases outbreak and over 200 000 die yearly from cholera. Also, the impact of a cholera epidemic is not limited to its high morbidity and mortality rates alone, but also the grievous impact on the economy of the countries experiencing the outbreaks. In this review, we carried out an overview of V. cholerae including its isolation and detection, genetics as well as a comparison of the toxigenic and non-toxigenic determinants in the human host and the host defences. Furthermore, the history of global pandemics, cost implications, conflict and ecological methodologies of cholera prevention and control. The management of disease and antibiotic resistance in V. cholerae are also highlighted.

  12. 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.

  13. 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.

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

    OpenAIRE

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

    1983-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Koski-Karell V

    2016-05-01

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

  16. [Large-scale selective antibiotic prophylaxis during the 2004 cholera outbreak in Douala (Cameroon)].

    Science.gov (United States)

    Guévart, Edouard; Noeske, Jürgen; Sollé, Jérémie; Mouangue, Antoine; Bikoti, Joseph-Marie

    2007-01-01

    During the 2004 cholera outbreak in Douala, densely populated and poor suburban populations had very poor access to safe drinking water and were at high risk of transmission. The provincial task force thus decided to provide preventive antibiotic treatment of all patient contacts, that is, family members taking care of patients in the hospital and household members of patients or close neighbours living in houses directly adjacent to patients. This retrospective report, based on data from hospitals, local cholera committees, and pharmacies, describes the course of the epidemic, bacteriological monitoring, and antibiotic distribution. Suddenly appearing in January 2004, the outbreak affected 5,020 patients in 8 months. V.cholerae, which was isolated in 111/187 samples, remained susceptible to doxycycline, amoxicillin, and fluoroquinolones. A total of 182,366 persons (35 contacts per patient) received antibiotic treatment. The rate of contacts among new patients fell from 30% to less than 0.2%. Antibiotic prophylaxis was a part of a comprehensive package of community interventions that included health education, disinfection of homes, latrines and wells in all affected households, and bacteriological monitoring. Although it reduces the risk of the disease, mass antibiotic prophylaxis is not recommended against cholera outbreaks, because it does not prevent contamination and is limited by contraindications, costs, and modes of administration. Moreover, it increases the risk of developing resistance. It is impossible to eradicate vibrio from the environment. The individual risk of contracting cholera is not known and it is difficult to assess the impact of a collective prevention strategy. Because the bacteria remains susceptible to antibiotic drugs, a well-targeted antibiotic prophylaxis made it possible to reduce direct human transmission of cholera. This reduction did not affect the overall epidemic, however, because of the massive environmental contamination. The

  17. Spreading of Cholera through Surface Water

    Science.gov (United States)

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

    2009-12-01

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

  18. Reduced osmolarity oral rehydration salt in Cholera.

    Science.gov (United States)

    Faruque, A S; Mahalanabis, D; Hamadani, J D; Zetterstrom, R

    1996-01-01

    In a controlled clinical trial conducted in 34 adults with severe cholera diarrhoea, the use of a relatively dilute oral rehydration salt (ORS) solution (sodium 67, potassium 20, chloride 66, citrate 7, glucose 89 mmol/l, osmolality 249 mOsmol/kg) caused a 29% (p=0.003) reduction in stool output over the first 24 h and a 37% (p=0.001) reduction over the first 48 h compared with 29 controls who received the hyperosmolar WHO/UNICEF ORS. No controls but 3 study-group patients had marked but asymptomatic hyponatraemia (sodium cholera.

  19. Resurgence of cholera in Hong Kong.

    OpenAIRE

    Lee, S. H.; Lai, S. T.; Lai, J. Y.; Leung, N K

    1996-01-01

    Cholera is one of the three diseases subject to the International Health Regulations. After a period of over 30 years, the seventh pandemic of cholera, which started in South East Asia in 1961, still shows no sign of a decline. On the contrary, it has increased its severity and invaded many other countries in Africa and Latin America. In the last two years, there has been a recrudescence of the disease in South East Asia and Western Pacific Regions. The discovery of a new strain of Vibrio cho...

  20. Chinese Calligraphy Word Spotting Using Elastic HOG Feature and Derivative Dynamic Time Warping

    Institute of Scientific and Technical Information of China (English)

    Yong Xia; Zhi-Bo Yang; Kuan-Quan Wang

    2014-01-01

    Chinese calligraphy is a very special style of handwriting and direct character recognition is very difficult. Content-based keyword spotting is more feasible than recognition-based retrieval for calligraphy document. In this paper, we propose a novel Elastic Histogram of Oriented Gradient ( EHOG) descriptor for calligraphy word spotting. The presented feature is a modification of Histogram of Oriented Gradient (HOG), widely used in human detection. In our approach, the input word image is partitioned into non-uniform rectangular cells according to the calligraphy character pixel intensity, and then in each cell a histogram of orientation is accumulated dynamically. Moreover, we adopt Derivative Dynamic Time Warping ( DDTW) for image feature matching, which achieves good performance in gesture recognition. Experiments demonstrate a very significant improvement when comparing our proposed feature with previously developed ones, and also show DDTW produces superior alignments between two calligraphy character feature series than DTW.

  1. HedgeHOGS: A Rapid Nuclear Hedge Sizing and Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Adam F. [United States Military Academy, West Point, NY (United States); Steinfeldt, Bradley Alexander [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Lafleur, Jarret Marshall [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hawley, Marilyn F. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Shannon, Lisa M. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-07-01

    The U.S. nuclear stockpile hedge is an inventory of non-deployed nuclear warheads and a force structure capable of deploying those warheads. Current guidance is to retain this hedge to mitigate the risk associated with the technical failure of any single warhead type or adverse geopolitical developments that could require augmentation of the force. The necessary size of the hedge depends on the composition of the nuclear stockpile and assumed constraints. Knowing the theoretical minimum hedge given certain constraints is useful when considering future weapons policy. HedgeHOGS, an Excel-based tool, was developed to enable rapid calculation of the minimum hedge size associated with varying active stockpile composition and hedging strategies.

  2. The case for reactive mass oral cholera vaccinations.

    Directory of Open Access Journals (Sweden)

    Rita Reyburn

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

  3. The case for reactive mass oral cholera vaccinations.

    Science.gov (United States)

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

    2011-01-25

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

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

    Directory of Open Access Journals (Sweden)

    Fahima Chowdhury

    2015-11-01

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

  5. Environmental bacteriophages active on biofilms and planktonic forms of toxigenic Vibrio cholerae: Potential relevance in cholera epidemiology.

    Science.gov (United States)

    Naser, Iftekhar Bin; Hoque, M Mozammel; Abdullah, Ahmed; Bari, S M Nayeemul; Ghosh, Amar N; Faruque, Shah M

    2017-01-01

    Phages isolated from environmental waters in Bangladesh were tested for their host specificity towards V. cholerae O1 and O139, and the ability to disperse V. cholerae biofilms formed in the laboratory. Representative phages were further characterized by electron microscopy and whole genome sequencing. Selected phages were then introduced in various combinations to biofilms of toxigenic V. cholerae added to samples of river water, and the dispersion of biofilms as well as the growth kinetics of V. cholerae and the phages were monitored. A phage cocktail composed of three different phages isolated from surface waters in Bangladesh and designated as JSF7, JSF4, and JSF3 could significantly influence the distribution and concentration of the active planktonic form and biofilm associated form of toxigenic V. cholerae in water. While JSF7 showed a biofilm degrading activity and dispersed cells from both V. cholerae O1 and O139 derived biofilms thus increasing the concentration of planktonic V. cholerae in water, JSF4 and JSF3 showed strong bactericidal activity against V. cholerae O1 and O139 respectively. A mixture of all three phages could effectively reduce both biofilm-associated and planktonic V. cholerae in river water microcosms. Besides potential applicability in phage-mediated control of cholera, our results have relevance in appreciating possible intricate role of diverse environmental phages in the epidemiology of the disease, since both biofilms and phages influence the prevalence and infectivity of V. cholerae in a variety of ways.

  6. 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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2016-10-27

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Moore, Sandra; Miwanda, Berthe; Sadji, Adodo Yao; Thefenne, Hélène; Jeddi, Fakhri; Rebaudet, Stanislas; de Boeck, Hilde; Bidjada, Bawimodom; Depina, Jean-Jacques; Bompangue, Didier; Abedi, Aaron Aruna; Koivogui, Lamine; Keita, Sakoba; Garnotel, Eric; Plisnier, Pierre-Denis; Ruimy, Raymond; Thomson, Nicholas; Muyembe, Jean-Jacques; Piarroux, Renaud

    2015-01-01

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

  11. Pentavalent outer membrane vesicles of Vibrio cholerae induce adaptive immune response and protective efficacy in both adult and passive suckling mice models.

    Science.gov (United States)

    Sinha, Ritam; Koley, Hemanta; Nag, Dhrubajyoti; Mitra, Soma; Mukhopadhyay, Asish K; Chattopadhyay, Brajadulal

    2015-03-01

    Recently, we demonstrated oral immunizations with single serotype outer membrane vesicles of Vibrio cholerae induced serogroup specific protective immunity in the RITARD model. In our present study, we advanced our research by formulating multi-serotype outer membrane vesicles, mixing the OMVs of five virulent V. cholerae strains. Four doses of oral immunization with cholera pentavalent outer membrane vesicles (CPMVs) induced V. cholerae specific B and T cell responses. CPMVs-immunized mice generated long lasting serum IgG, IgA, IgM as well as mucosal sIgA and also elicited a higher percentage of CD4+ T cell distribution in spleen. Our study revealed that in vitro CPMVs-activated dendritic cells were secreting T cell polarizing cytokines, IL-12p40, IL-4, IL-6 and IL-1β. Moreover, purified splenic CD4+ T cells of immunized mice also secreted IL-4, IL-13 and IL-17 cytokines, indicating the initiation of Th2 and Th17 cell mediated immune responses. CPMVs immunized adult female mice and their offspring were significantly protected from heterologous challenge with wild type V. cholerae. CPMVs could be exploited for the development of a novel non-living vaccine against circulating cholera in near future.

  12. Rapid Motion Human Detection Based on Background Subtraction and HOG-LBP%基于背景差与HOG-LBP的快速运动人体检测

    Institute of Scientific and Technical Information of China (English)

    张慧; 郑爱华; 涂铮铮; 罗斌

    2015-01-01

    For the case of close monitoring by monocular static camera,propose a rapid motion human detection algorithm combined with target movement external rectangular length-width ratio,including two steps of moving objects extraction and moving human detection. The moving target extraction is implemented by combining the frame difference and background subtraction,where the frame difference is used to update the background and background subtraction is used to extract the moving target. Moving target discrimination that is human detection can be divided into two parts,the single movement human detection and the crowd detection. Firstly,according to the empirical value of length-width ratio of bounding rectangle of the extracted moving target,the target is divided into single-object and multi-ob-ject. Then,single-object is determined according to the skin color distribution. For multi-object,HOG-LBP features are extracted,fol-lowed by PCA ( Principal Component Analysis) dimensionality reduction. Then the multi-object discrimination is approached by combi-ning with the linear SVM. The experimetal results show the remarkable performance of this method is improved on both detection rate and efficiency.%针对单目静止摄像机近距离监控的情形,结合运动目标外接矩形长宽比,提出一种HOG特征联合LBP特征并通过PCA降维的快速运动人体检测算法。该方法包含两个步骤:运动目标提取和运动人体检测。使用帧差与背景差相结合的方法提取运动目标,帧差用于更新背景,背景差用于提取运动目标。运动目标判别即人体检测分为两个部分:单运动人体检测以及多运动人体检测。首先根据运动目标外接矩形的长宽比,把目标分为单目标以及多目标;然后,根据肤色的分布判断单个行人。对于多目标,提取HOG-LBP特征,用PCA降维,结合线性SVM进行群人目标判定。实验结果表明,该方法不仅提高了人体检

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

    Science.gov (United States)

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

    2013-10-01

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

  14. Hybrid Vibrio cholerae El Tor lacking SXT identified as the cause of a cholera outbreak in the Philippines.

    Science.gov (United States)

    Klinzing, David C; Choi, Seon Young; Hasan, Nur A; Matias, Ronald R; Tayag, Enrique; Geronimo, Josefina; Skowronski, Evan; Rashed, Shah M; Kawashima, Kent; Rosenzweig, C Nicole; Gibbons, Henry S; Torres, Brian C; Liles, Veni; Alfon, Alicia C; Juan, Maria Luisa; Natividad, Filipinas F; Cebula, Thomas A; Colwell, Rita R

    2015-04-21

    Cholera continues to be a global threat, with high rates of morbidity and mortality. In 2011, a cholera outbreak occurred in Palawan, Philippines, affecting more than 500 people, and 20 individuals died. Vibrio cholerae O1 was confirmed as the etiological agent. Source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. In this study, three V. cholerae O1 isolates from a Philippines cholera outbreak were sequenced and their genomes analyzed to determine phylogenetic relatedness to V. cholerae O1 isolates from recent outbreaks of cholera elsewhere. The Philippines V. cholerae O1 isolates were determined to be V. cholerae O1 hybrid El Tor belonging to the seventh-pandemic clade. They clustered tightly, forming a monophyletic clade closely related to V. cholerae O1 hybrid El Tor from Asia and Africa. The isolates possess a unique multilocus variable-number tandem repeat analysis (MLVA) genotype (12-7-9-18-25 and 12-7-10-14-21) and lack SXT. In addition, they possess a novel 15-kb genomic island (GI-119) containing a predicted type I restriction-modification system. The CTXΦ-RS1 array of the Philippines isolates was similar to that of V. cholerae O1 MG116926, a hybrid El Tor strain isolated in Bangladesh in 1991. Overall, the data indicate that the Philippines V. cholerae O1 isolates are unique, differing from recent V. cholerae O1 isolates from Asia, Africa, and Haiti. Furthermore, the results of this study support the hypothesis that the Philippines isolates of V. cholerae O1 are indigenous and exist locally in the aquatic ecosystem of the Philippines. Genetic characterization and phylogenomics analysis of outbreak strains have proven to be critical for probing clonal relatedness to strains isolated in different geographical regions and over time. Recently, extensive genetic analyses of V. cholerae O1 strains isolated in different countries have been done. However, genome sequences of V. cholerae O1

  15. Outbreak of cholera caused by Vibrio cholerae O1 El Tor variant strain in Bihar, India.

    Science.gov (United States)

    Koley, Hemanta; Ray, Nivedita; Chowdhury, Goutam; Barman, Soumik; Mitra, Soma; Ramamurthy, T; Mukhopadhyay, Asish K; Sarkar, B L; Katyal, Rakesh; Das, Pradeep; Panda, Samiran; Ghosh, Subrata

    2014-01-01

    An outbreak of cholera struck Bihar, an Indian state, in August 2008 following a massive flood. Here we report the phenotypic and genotypic characteristics of Vibrio cholerae strains isolated from patients with diarrhea. Rectal swabs were obtained from patients with diarrhea who were admitted to medical camps or the hospital, and the strains were biochemically and serologically characterized. V. cholerae was isolated from 21 (65.6%) of 32 rectal swabs. Serological studies revealed that all the 21 isolates belonged to V. cholerae O1 Ogawa. Mismatch amplification mutation assay (MAMA)-PCR showed that the isolates belonged to El Tor variant group, and pulsed-field gel electrophoresis (PFGE) proved that these isolates were of a different lineage than the conventional El Tor variant strains. These isolates were resistant to several drugs, including ampicillin, streptomycin, tetracycline, nalidixic acid, and furazolidone. The uniqueness of the current report arises from the fact that records of cholera in Bihar are availiable for the early 1960s but not for the next 4 decades. Moreover, the present study is the first to report a cholera outbreak in Bihar that was caused by an El Tor variant strain.

  16. Molecular characterization of the circulating strains of Vibrio cholerae during 2010 cholera outbreak in Nigeria.

    Science.gov (United States)

    Oyedeji, Kolawole S; Niemogha, Mary-Theresa; Nwaokorie, Francisca O; Bamidele, Tajudeen A; Ochoga, Michael; Akinsinde, Kehinde A; Brai, Bartholomew I; Oladele, David; Omonigbehin, Emmanuel A; Bamidele, Moses; Fesobi, Toun W; Musa, Adesola Z; Adeneye, Adeniyi K; Smith, Stella I; Ujah, Innocent A

    2013-06-01

    This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria.

  17. Cholera Toxin Production Induced upon Anaerobic Respiration is Suppressed by Glucose Fermentation in Vibrio cholerae.

    Science.gov (United States)

    Oh, Young Taek; Lee, Kang-Mu; Bari, Wasimul; Kim, Hwa Young; Kim, Hye Jin; Yoon, Sang Sun

    2016-03-01

    The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

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

    Directory of Open Access Journals (Sweden)

    Salah Shanan

    2016-04-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Serological Survey in Pig Herds Immunized with Hog Cholera Vaccine%猪瘟免疫接种抗体效价检测试验

    Institute of Scientific and Technical Information of China (English)

    周相华; 韩喜连

    2006-01-01

    猪瘟只有一个血清型,免疫注射是防止猪瘟的重要手段。我国猪瘟兔化弱毒苗自1956年研制成功以来,在全国各地广泛应用,证明安全有效。免疫疫苗24小时后,即可抵抗自然感染,第3天产生可靠的免疫力;在疫区对体温及体况正常的猪用此苗紧急接种,能迅速终止疫情发展。断奶仔猪接种疫苗后产生的免疫期至少1年。幼年仔猪的免疫期视其由初乳获得的母源抗体而异,有的达1年,有的不及1个月。仔猪获得的母源抗体,一般可维持30~45d,对主动免疫力的产生有干扰作用。如免疫过早,因母源抗体水平高,产生的免疫力差,免疫期很短,因而有接种后不久发生猪瘟的情况;如免疫过迟,仔猪在母源抗体下降到不能预防感染的水平后,则有发病的危险。因此,从技术、管理等方面层层抓好疫苗预防接种工作,是防制猪瘟的重要措施。为了解猪瘟免疫接种效果及存在的问题,进一步掌握仔猪母源抗体情况,选择了24个商品代养猪场,采集全血分离血清,进行猪瘟抗体效价检测试验。

  1. 猪瘟疫苗超前免疫效果观察%Effect of Inoculate Time on Hog Cholera Virus Vaccine

    Institute of Scientific and Technical Information of China (English)

    罗勇; 陈创夫; 杨建疆; 荣进

    2006-01-01

    本试验旨在确定猪瘟首次免疫的最佳时间:试验中将29只仔猪分为3组分别于吸初乳前1 h、吸初乳时、吸初乳后1 h对仔猪进行猪瘟疫苗注射,利用酶标仪检测免疫后15 h、30 h、40 h、50h时积各组仔猪体内抗体水平.结果显示:超前免疫仔猪抗体水平明显高于其它两组.

  2. Microbiological status of live eel and processed fish products for export to Japan.

    Science.gov (United States)

    Rohaya, M A; Chuink, B H; Aniran, K

    1997-01-01

    Live eels and processed fish products from Malaysia are routinely checked for microbial pathogens before export to Japan. The eels and water from the ponds are screened for Vibrio cholerae and Salmonella spp, whereas the processed fish products are tested for microbial contamination (aerobic plate count), coliforms, E. coil and Vibrio cholerae. Results showed that live eels and water samples were negative for Vibrio cholerae but Salmonella spp were isolated occasionally. Various types of processed fish products had counts below 1.0 x 10(5) whilst coliforms, E. coli and Vibrio cholerae were absent. Records available showed that procedures involved in the production and transportation of live eel, preparation and processing of fish products have resulted in relatively safe food products.

  3. WAKTU REGENERASI BAKTERI Vibrio cholerae PADA MEDIUM APW

    Directory of Open Access Journals (Sweden)

    Kambang Sariadji

    2015-04-01

    Full Text Available AbstractWater and food could be contaminated by Vibrio cholerae which caused diarrhea to someone consumed them;serious cholerae disease could lead to death. In extreme environments cholerae could be in viable but nonculturable. Epidemiologically, this condition has contributed cholera outbreaks events. On the contrary, the bacteria can grow quickly in favorable conditions,. However, information about the cholerae growthing rate are still limited. The aims of research wes To determine the regeneration time of cholerae from time to time in optimum condition, as a base of assestment during cholerae outbreaks. The number of cholerae cells in 101 cfu / mL were made by dilution, then determined thenumber of bacteria in the beginning by using the colony count method with Thio sulfate Citrate Bile Sucrose (TCBS media. the growth rate of bacteria was determinated by inoculated 2 mL dilution 101 cfu / mL to the enrichment alkaline peptone water (APW media and then incubated at 37°C. Every one hour up to the end of eight hours, the bacteria were measured by colony count method using TCBS media. The obtaining of results were calculated by specified regeneration time. The results showedthat v. Cholerae generate between 8-15 minite from time to time in 8 hoursKeywords : Vibrio cholerae, Colony count, regeneration timeAbstrakVibrio cholerae dapat menjadi pencemar pada air dan makanan yang dapat menyebabkan diare pada seseorang yang mengkonsumsinya. Penderita penyakit kolera pada kasus yang berat dapat menyebabkankematian. Vibrio cholerae pada lingkungan yang ekstrim dapat menjadi viable but nonculturable, sehingga secara epidemiologi lingkungan ini mempunyai andil dalam menyebabkan wabah kolera. Sementara pada kondisi yang menguntungkan, bakteri ini dapat tumbuh dengan cepat. Namun informasi tentang kecepatan pertumbuhan dari cholerae sebagai antisipasi tindakan pencegahan wabah masih sangat terbatas. Tujuan penelitian ini untuk mengetahui waktu regenerasi

  4. Social and news media enable estimation of epidemiological patterns early in the 2010 Haitian cholera outbreak

    National Research Council Canada - National Science Library

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

    2012-01-01

    .... We assessed correlation of volume of cholera-related HealthMap news media reports, Twitter postings, and government cholera cases reported in the first 100 days of the 2010 Haitian cholera outbreak...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    Natalia Olsson Markelova

    2015-12-01

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

  7. Use of Oral Cholera Vaccine in Haiti: A Rural Demonstration Project

    Science.gov (United States)

    Ivers, Louise C.; Teng, Jessica E.; Lascher, Jonathan; Raymond, Max; Weigel, Jonathan; Victor, Nadia; Jerome, J. Gregory; Hilaire, Isabelle J.; Almazor, Charles P.; Ternier, Ralph; Cadet, Jean; Francois, Jeannot; Guillaume, Florence D.; Farmer, Paul E.

    2013-01-01

    A cholera epidemic has claimed the lives of more than 8,000 Haitians and sickened 650,000 since the outbreak began in October 2010. Early intervention in the epidemic focused on case-finding, treatment, and water and sanitation interventions for prevention of transmission. Use of oral cholera vaccine (OCV) as part of a complementary set of control activities was considered but initially rejected by policymakers. In December 2011, the Minister of Health of Haiti called for a demonstration of the acceptability and feasibility of the use of OCV in urban and rural Haiti. This paper describes the collaborative activity that offered OCV to one region of the Artibonite Department of rural Haiti in addition to other ongoing treatment and control measures. Despite logistics and cold chain challenges, 45,417 persons were successfully vaccinated with OCV in the region, and 90.8% of these persons completed their second dose. PMID:24106187

  8. Cholera: Environmental Reservoirs and Impact on Disease Transmission

    Science.gov (United States)

    ALMAGRO-MORENO, SALVADOR; TAYLOR, RONALD K.

    2015-01-01

    Vibrio cholerae is widely known to be the etiological agent of the life-threatening diarrheal disease cholera. Cholera remains a major scourge in many developing countries, infecting hundreds of thousands every year. Remarkably, V. cholerae is a natural inhabitant of brackish riverine, estuarine, and coastal waters, and only a subset of strains are known to be pathogenic to humans. Recent studies have begun to uncover a very complex network of relationships between V. cholerae and other sea dwellers, and the mechanisms associated with the occurrence of seasonal epidemics in regions where cholera is endemic are beginning to be elucidated. Many of the factors required for the organism’s survival and persistence in its natural environment have been revealed, as well as the ubiquitous presence of horizontal gene transfer in the emergence of pathogenic strains of V. cholerae. In this article, we will focus on the environmental stage of pathogenic V. cholerae and the interactions of the microorganism with other inhabitants of aquatic environments. We will discuss the impact that its environmental reservoirs have on disease transmission and the distinction between reservoirs of V. cholerae and the vectors that establish cholera as a zoonosis. PMID:25674360

  9. Plasma Leptin Levels in Children Hospitalized with Cholera in Bangladesh.

    Science.gov (United States)

    Falkard, Brie; Uddin, Taher; Rahman, M Arifur; Franke, Molly F; Aktar, Amena; Uddin, Muhammad Ikhtear; Bhuiyan, Taufiqur Rahman; Leung, Daniel T; Charles, Richelle C; Larocque, Regina C; Harris, Jason B; Calderwood, Stephen B; Qadri, Firdausi; Ryan, Edward T

    2015-08-01

    Vibrio cholerae, the cause of cholera, induces both innate and adaptive immune responses in infected humans. Leptin is a hormone that plays a role in both metabolism and mediating immune responses. We characterized leptin levels in 11 children with cholera in Bangladesh, assessing leptin levels on days 2, 7, 30, and 180 following cholera. We found that patients at the acute stage of cholera had significantly lower plasma leptin levels than matched controls, and compared with levels in late convalescence. We then assessed immune responses to V. cholerae antigens in 74 children with cholera, correlating these responses to plasma leptin levels on day 2 of illness. In multivariate analysis, we found an association between day 2 leptin levels and development of later anti-cholera toxin B subunit (CtxB) responses. This finding appeared to be limited to children with better nutritional status. Interestingly, we found no association between leptin levels and antibody responses to V. cholerae lipopolysaccharide, a T cell-independent antigen. Our results suggest that leptin levels may be associated with cholera, including the development of immune responses to T cell-dependent antigens. © The American Society of Tropical Medicine and Hygiene.

  10. Effect of Dietary Minerals on Virulence Attributes of Vibrio cholerae.

    Science.gov (United States)

    Bhattaram, Varunkumar; Upadhyay, Abhinav; Yin, Hsin-Bai; Mooyottu, Shankumar; Venkitanarayanan, Kumar

    2017-01-01

    Vibrio cholerae is a water-borne pathogen responsible for causing a toxin-mediated profuse diarrhea in humans, leading to severe dehydration and death in unattended patients. With increasing reports of antibiotic resistance in V. cholerae, there is a need for alternate interventional strategies for controlling cholera. A potential new strategy for treating infectious diseases involves targeting bacterial virulence rather than growth, where a pathogen's specific mechanisms critical for causing infection in hosts are inhibited. Since bacterial motility, intestinal colonization and cholera toxin are critical components in V. cholerae pathogenesis, attenuating these virulence factors could potentially control cholera in humans. In this study, the efficacy of sub-inhibitory concentration (SIC, highest concentration not inhibiting bacterial growth) of essential minerals, zinc (Zn), selenium (Se), and manganese (Mn) in reducing V. cholerae motility and adhesion to intestinal epithelial cells (Caco-2), cholera toxin production, and toxin binding to the ganglioside receptor (GM1) was investigated. Additionally, V. cholerae attachment and toxin production in an ex vivo mouse intestine model was determined. Further, the effect of Zn, Se and Mn on V. cholerae virulence genes, ctxAB (toxin production), fliA (motility), tcpA (intestinal colonization), and toxR (master regulon) was determined using real-time quantitative PCR. All three minerals significantly reduced V. cholerae motility, adhesion to Caco-2 cells, and cholera toxin production in vitro, and decreased adhesion and toxin production in mouse intestine ex vivo (P cholerae virulence. However, in vivo studies in an animal model are necessary to validate these results.

  11. 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

  12. A Natural Vaccine Candidate Strain Against Cholera

    Institute of Scientific and Technical Information of China (English)

    LIUYAN-QING; QIGUO-MING; 等

    1995-01-01

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

  13. Preventing Maritime Transfer of Toxigenic Vibrio cholerae

    Science.gov (United States)

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

    2012-01-01

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

  14. Surface-attachment sequence in Vibrio Cholerae

    Science.gov (United States)

    Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard

    2013-03-01

    Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

  15. EFFECT OF AGGREGATION ON VIBRIO CHOLERAE INACTIVATION

    Science.gov (United States)

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

  16. 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.

  17. 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.

  18. Invasive Vibrio cholerae Infection Following Burn Injury

    Science.gov (United States)

    2008-06-01

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

  19. Survey on antimicrobial resistance patterns in Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 in Germany reveals carbapenemase-producing Vibrio cholerae in coastal waters.

    Science.gov (United States)

    Bier, Nadja; Schwartz, Keike; Guerra, Beatriz; Strauch, Eckhard

    2015-01-01

    An increase in the occurrence of potentially pathogenic Vibrio species is expected for waters in Northern Europe as a consequence of global warming. In this context, a higher incidence of Vibrio infections is predicted for the future and forecasts suggest that people visiting and living at the Baltic Sea are at particular risk. This study aimed to investigate antimicrobial resistance patterns among Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 isolates that could pose a public health risk. Antimicrobial susceptibility of 141 V. vulnificus and 184 V. cholerae non-O1/non-O139 strains isolated from German coastal waters (Baltic Sea and North Sea) as well as from patients and retail seafood was assessed by broth microdilution and disk diffusion. Both species were susceptible to most of the agents tested (12 subclasses) and no multidrug-resistance was observed. Among V. vulnificus isolates, non-susceptibility was exclusively found toward aminoglycosides. In case of V. cholerae, a noticeable proportion of strains was non-susceptible to aminopenicillins and aminoglycosides. In addition, resistance toward carbapenems, quinolones, and folate pathway inhibitors was sporadically observed. Biochemical testing indicated the production of carbapenemases with unusual substrate specificity in four environmental V. cholerae strains. Most antimicrobial agents recommended for treatment of V. vulnificus and V. cholerae non-O1/non-O139 infections were found to be effective in vitro. However, the occurrence of putative carbapenemase producing V. cholerae in German coastal waters is of concern and highlights the need for systematic monitoring of antimicrobial susceptibility in potentially pathogenic Vibrio spp. in Europe.

  20. 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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  4. 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

  5. Specific dielectric constant-temperature characteristics of the hog brain and the skull; Buta no no to hone no hiyudenritsu - ondo tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Y.; Shida, K. [Saga University, Saga (Japan)

    1998-02-01

    The final purpose of our study is the non-invasive measurement of the brain temperature change by head capacitance measurements. Establishment of this technique might be useful for the diagnosis of brain death, since it is reported that in the brain death the brain temperature is influenced by the surrounding temperature change. It is necessary for the establishment of this technique to acquire knowledge of the specific dielectric constant - temperature characteristics of the human head tissue. For this purpose, we examined the specific dielectric constant - temperature characteristics of the hog brain and skull which were obtained immediately after the death. As the experiment result, we estimated the specific dielectric constant to be about 1300 for the brain and around 3 for the skull in living condition, and its temperature coefficient about 1.84 %/degC for the brain and around 0.23 %/degC for the skull. Applying those estimated values to the human head, it was demonstrated to be possible to detect the change in human brain temperature from 37degC to 36degC by measuring the capacitance of the human head model consisting of only the brain and the skull across a pair of measurement electrodes of 1 cm{sup 2} area, under the condition of voltage in 20 V with 500 kHz. 15 refs., 11 figs.

  6. Cloning of hog1 gene fragment from Dunalilla salina using CODEHOP-designed degenerate primers%用CODEHOP设计简并引物克隆杜氏盐藻hog1基因片段

    Institute of Scientific and Technical Information of China (English)

    王传胜; 蒋彦

    2012-01-01

    根据NCBI上已经报道的hog1序列,利用简并引物在线设计工具CODEHOP设计出两对简并引物,通过巢式PCR扩增,得到一段大小为635 bp的基因片段,将其克隆到T载体上并测序,将测得的序列在NCBI的Blast搜索发现,其与已报道的其他一些物种的hog1基因有同源性.用CODEHOP程序化设计简并引物可信性强,阳性率高.该基因的成功克隆为研究杜氏盐藻的HOG信号途径奠定了基础.%According to the published sequence of hogl from NCBI database, we designed the degenerate primers of hogl using CODEHOP software. Using these degenerate primers, a partial hogl cDNA of 635bp was amplified from Dunalilla salina and cloned into T vector. Sequence analysis showed that the cloned hogl shares high sequence identity to those of hogl from other species. The results indicated that the degenerate primers designed by the CODEHOP could be used to amplify specific gene fragment. Clo ning of hogl gene fragment would be helpful to further characterize the HOG signaling pathway of Dunalilla salina.

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2011-04-12

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

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

    Directory of Open Access Journals (Sweden)

    Sridhar Elluri

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

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

    Science.gov (United States)

    Sánchez, J; Holmgren, J

    2008-05-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  12. Evolutionary perspective on the origin of Haitian cholera outbreak strain.

    Science.gov (United States)

    Dasgupta, Anirban; Banerjee, Rachana; Das, Santasabuj; Basak, Surajit

    2012-01-01

    Cholera epidemic has not been reported in Haiti for at least 100 years, although cholera has been present in Latin America since 1991. Surprisingly, the recent cholera epidemic in Haiti (October 2010) recorded more than 250,000 cases and 4000 deaths in the first 6 months and became one of the most explosive and deadly cholera outbreak in recent history. In the present study, we conducted genomic analyses of pathogenicity islands of three Haitian Vibrio cholerae strains and compared them with nine different V. cholerae O1 El Tor genomes. Although CIRS101 is evolutionarily most similar to the Haitian strains, our study also provides some important differences in the genetic organization of pathogenicity islands of Haitian strains with CIRS101. Evolutionary analysis suggests that unusual functional constraints have been imposed on the Haitian strains and we hypothesize that amino acid substitution is more deleterious in Haitian strains than in nonHaitian strains.

  13. The role of Vibrio cholerae genotyping in Africa.

    Science.gov (United States)

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

    2013-11-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Dorsal hand vein recognition based on Gabor multi-orientation fusion and multi-scale HOG features

    Science.gov (United States)

    Han, Tuo; Wang, Zhiyong; Yang, Xiaoping

    2016-10-01

    Kinds of factors such as illumination and hand gestures would reduce the accuracy of dorsal hand vein recognition. Aiming at single hand vein image with low contrast and simple structure, an algorithm combining Gabor multi-orientation features fusion with Multi-scale Histogram of Oriented Gradient (MS-HOG) is proposed in this paper. With this method, more features will be extracted to improve the recognition accuracy. Firstly, diagrams of multi-scale and multi-orientation are acquired using Gabor transformation, then the Gabor features of the same scale and multi-orientation will be fused, and the features of the correspondent fusion diagrams will be extracted with a HOG operator of a certain scale. Finally the multi-scale cascaded histograms will be obtained for hand vein recognition. The experimental results show that our method not only improve the recognition accuracy but has good robustness in dorsal hand vein recognition.

  16. Carnitine uptake by AGP2 in yeast Saccharomyces cerevisiae is dependent on Hog1 MAP kinase pathway.

    Science.gov (United States)

    Lee, Jiyoung; Lee, Boyoung; Shin, Dongjin; Kwak, Sang-Soo; Bahk, Jeong Dong; Lim, Chae Oh; Yun, Dae-Jin

    2002-06-30

    The AGP2 gene encodes a plasma membrane carnitine transporter in S. cerevisiae. Here, we report the identification of AGP2 as an osmotic stress response gene. AGP2 was isolated from mTn3 tagged mutants that contained in-frame fusions with lacZ. The expression of AGP2 was down-regulated by osmotic stresses, including NaCl, sorbitol, and KCI. We also found that carnitine uptake was inhibited by NaCl. In the ssk1delta stelldelta double-mutant strain, the expression of AGP2 and the uptake of carnitine were greatly reduced compared to the wild-type strain. Furthermore, carnitine uptake was inhibited by the constitutive expression of PBS2, which encodes a MAPKK that activates Hog1. We concluded, therefore, that the HOG pathway plays an important role in the regulation of carnitine uptake in S. cerevisiae.

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

    Science.gov (United States)

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

    2009-05-01

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

  18. 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

  19. The value of and challenges for cholera vaccines in Africa.

    OpenAIRE

    von Seidlein, Lorenz; Jiddawi, Mohammad; Grais, Rebecca F.; Luquero, Francisco; Lucas, Marcelino; Deen, Jacqueline

    2013-01-01

    The 21st century saw a shift in the cholera burden from Asia to Africa. The risk factors for cholera outbreaks in Africa are incompletely understood, and the traditional emphasis on providing safe drinking water and improving sanitation and hygiene has proven remarkably insufficient to contain outbreaks. Current killed whole-cell oral cholera vaccines (OCVs) are safe and guarantee a high level of protection for several years. OCVs have been licensed for >20 years, but their potential for prev...

  20. Cholera revolts: a class struggle we may not like

    OpenAIRE

    Cohn Jr, Samuel Kline

    2017-01-01

    Few have studied cholera revolts comparatively, and certainly not over the vast terrain from Asiatic Russia to Quebec or across time from the first European cholera wave of the 1830s to the twentieth century. Scholars have instead concentrated on the first European cholera wave in the 1830s and have tended to explain cholera’s social violence within the political contexts of individual nations, despite these riots raging across vast differences in political landscapes from Czarist Russia to N...

  1. Cholera-like diarrhoea due to Salmonella infection.

    Science.gov (United States)

    Saidi, Suleiman Mzee; Yamasaki, Shinji; Lijima, Yoshio; Kariuki, Sam

    2011-02-01

    An unusually high number of sporadic cholera outbreaks have occurred in various parts of Kenya since January 2009. Clinical symptoms of cholera play an important role in the diagnosis and management of the disease, especially in resource-poor settings in most developing countries. We describe a case report of a patient who was treated for cholera according to symptoms at presentation to hospital. Non-typhoid Salmonella was later isolated and the patient's condition improved after administration of ciprofloxacin.

  2. Vaccines for Cholera Control: Does Herd Immunity Play a Role?

    OpenAIRE

    Ira M Longini; Azhar Nizam; Mohammad Ali; Mohammad Yunus; Neeta Shenvi; John D Clemens

    2007-01-01

    Editors' Summary Background. Throughout history, there have been devastating outbreaks of cholera—a gut infection characterized by diarrhea and severe dehydration—around the world. These days, cholera is mainly confined to developing countries where it disrupts social structures, impedes economic development, and probably causes about 100,000 deaths a year. People get cholera, which is caused by a bacterium called Vibrio cholerae, by eating food or drinking water contaminated with feces (stoo...

  3. Cold exposure affects carbohydrates and lipid metabolism, and induces Hog1p phosphorylation in Dekkera bruxellensis strain CBS 2499.

    Science.gov (United States)

    Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Zambelli, Paolo; Simonetti, Paolo; Foschino, Roberto; Compagno, Concetta

    2015-05-01

    Dekkera bruxellensis is a yeast known to affect the quality of wine and beer. This species, due to its high ethanol and acid tolerance, has been reported also to compete with Saccharomyces cerevisiae in distilleries producing fuel ethanol. In order to understand how this species responds when exposed to low temperatures, some mechanisms like synthesis and accumulation of intracellular metabolites, changes in lipid composition and activation of the HOG-MAPK pathway were investigated in the genome sequenced strain CBS 2499. We show that cold stress caused intracellular accumulation of glycogen, but did not induce accumulation of trehalose and glycerol. The cellular fatty acid composition changed after the temperature downshift, and a significant increase of palmitoleic acid was observed. RT-PCR analysis revealed that OLE1 encoding for Δ9-fatty acid desaturase was up-regulated, whereas TPS1 and INO1 didn't show changes in their expression. In D. bruxellensis Hog1p was activated by phosphorylation, as described in S. cerevisiae, highlighting a conserved role of the HOG-MAP kinase signaling pathway in cold stress response.

  4. The scenario approach for countries considering the addition of oral cholera vaccination in cholera preparedness and control plans.

    Science.gov (United States)

    Deen, Jacqueline; von Seidlein, Lorenz; Luquero, Francisco J; Troeger, Christopher; Reyburn, Rita; Lopez, Anna Lena; Debes, Amanda; Sack, David A

    2016-01-01

    Oral cholera vaccination could be deployed in a diverse range of situations from cholera-endemic areas and locations of humanitarian crises, but no clear consensus exists. The supply of licensed, WHO-prequalified cholera vaccines is not sufficient to meet endemic and epidemic needs worldwide and so prioritisation is needed. We have developed a scenario approach to systematically classify situations in which oral cholera vaccination might be useful. Our scenario approach distinguishes between five types of cholera epidemiology based on experiences from around the world and provides evidence that we hope will spur the development of detailed guidelines on how and where oral cholera vaccines could, and should, be most rationally deployed. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Cerda, Rodrigo; Lee, Patrick T

    2013-11-01

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

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

    Science.gov (United States)

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

    1977-04-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  8. Epidemic cholera among refugees in Malawi, Africa: treatment and transmission.

    Science.gov (United States)

    Swerdlow, D L; Malenga, G; Begkoyian, G; Nyangulu, D; Toole, M; Waldman, R J; Puhr, D N; Tauxe, R V

    1997-06-01

    Between 23 August and 15 December 1990 an epidemic of cholera affected Mozambican refugees in Malawi causing 1931 cases (attack rate = 2.4%); 86% of patients had arrived in Malawi cholerae O1, serotype Inaba, was isolated from patients and stored household water. The rapidity with which newly arrived refugees became infected precluded effective use of a cholera vaccine to prevent cases unless vaccination had occurred immediately upon camp arrival. Improved access to treatment and care of paediatric patients, and increased use of oral rehydration therapy, could decrease mortality. Preventing future cholera outbreaks in Africa will depend on interrupting both waterborne and foodborne transmission of this pathogen.

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

    Science.gov (United States)

    Clemens, John; Holmgren, Jan

    2014-01-01

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

  10. Circulation and transmission of clones of Vibrio cholerae during cholera outbreaks.

    Science.gov (United States)

    Stine, O Colin; Morris, J Glenn

    2014-01-01

    Cholera is still a major public health problem. The underlying bacterial pathogen Vibrio cholerae (V. cholerae) is evolving and some of its mutations have set the stage for outbreaks. After V. cholerae acquired the mobile elements VSP I & II, the El Tor pandemic began and spread across the tropics. The replacement of the O1 serotype encoding genes with the O139 encoding genes triggered an outbreak that swept across the Indian subcontinent. The sxt element generated a third selective sweep and most recently a fourth sweep was associated with the exchange of the El Tor ctx allele for a classical ctx allele in the El Tor background. In Kenya, variants of this fourth selective sweep have differentiated and become endemic residing in and emerging from environmental reservoirs. On a local level, studies in Bangladesh have revealed that outbreaks may arise from a nonrandom subset of the genetic lineages in the environment and as the population of the pathogen expands, many novel mutations may be found increasing the amount of genetic variation, a phenomenon known as a founder flush. In Haiti, after the initial invasion and expansion of V. cholerae in 2010, a second outbreak occurred in the winter of 2011-2012 driven by natural selection of specific mutations.

  11. Role of the HaHOG1 MAP kinase in response of the conifer root and butt rot pathogen (heterobasidion annosum to osmotic and oxidative stress [corrected].

    Directory of Open Access Journals (Sweden)

    Tommaso Raffaello

    Full Text Available The basidiomycete Heterobasidion annosum (Fr. Bref. s.l. is a filamentous white rot fungus, considered to be the most economically important pathogen of conifer trees. Despite the severity of the tree infection, very little is known about the molecular and biochemical aspects related to adaptation to abiotic stresses. In this study, the osmotic and oxidative tolerance as well as the role of the HaHOG1 Mitogen Activated Protein Kinase (MAPK gene were investigated. The transcript levels of the yeast orthologues GPD1, HSP78, STL1, GRE2 and the ATPase pumps ENA1, PMR1, PMC1 known to have an important role in osmotolerance were also quantified under salt osmotic conditions. The HaHOG1 gene was used for a heterologous expression and functional study in the Saccharomyces cerevisiae Δhog1 strain. Moreover, the phosphorylation level of HaHog1p was studied under salt osmotic and oxidative stress. The result showed that H. annosum displayed a decreased growth when exposed to an increased concentration of osmotic and oxidative stressors. GPD1, HSP78, STL1 and GRE2 showed an induction already at 10 min after exposure to salt stress. Among the ATPase pumps studied, PMC1 was highly induced when the fungus was exposed to 0.2 M CaCl₂ for 60 min. The heterologous expression of the HaHOG1 sequence in yeast confirmed that the gene is able to restore the osmotolerance and oxidative tolerance in the S. cerevisiae hog1Δ mutant strain. The HaHog1p was strongly phosphorylated in the presence of NaCl, KCl, H₂O₂ but not in the presence of CaCl₂ and MgCl₂. The GFP-HaHog1p fusion protein accumulated in the nuclei of the S. cerevisiae hog1Δ cells when exposed to high osmotic conditions but not under oxidative stress. These results provide the first insights about the response of H. annosum to osmotic and oxidative stress and elucidate the role of the HaHOG1 gene in such conditions.

  12. Retrospective analysis of the cholera cases imported to France from 1973 to 2005.

    Science.gov (United States)

    Tarantola, Arnaud; Ioos, Sophie; Rotureau, Brice; Paquet, Christophe; Quilici, Marie-Laure; Fournier, Jean-Michel

    2007-01-01

    The manners of traveling and travelers' vulnerability to infection are changing: increasing numbers of travelers, travels at the extreme ages of life, "backpacker" tourism in close contact with local populations. What is the epidemiologic situation and what are the trends of imported cholera to Metropolitan France? A descriptive retrospective study was undertaken on all the confirmed cases of cholera imported to France, and notified from January 1, 1973, to December 31, 2005, using compulsory notification data from local health departments and information from the National Reference Centre. A total of 129 imported cases of cholera were notified between 1973 and 2005 (3.9 cases/y on average). The geographical sources of infection have changed with time: in the 1980s, 94% of the patients were infected in Maghreb (Morocco and Algeria) but none were in 2000. On the other hand, Asia and West Africa progressively emerged and now predominate. In spite of certain poorly informed data and possible underdetection, the number of cases of importation appears to be low and falling. The patient profile seems to have evolved and increasingly concerns people at the extreme ages of life, living elsewhere than the principal basins of immigration in France, and diagnosis is increasingly made in nonteaching hospitals. The lessons likely to help clinicians will be discussed.

  13. Oral Cholera Vaccine Coverage during an Outbreak and Humanitarian Crisis, Iraq, 2015

    Science.gov (United States)

    Al-Tamimi, Wasan; Russell, Steven Paul; Butt, Muhammad Obaid-ul Islam; Blanton, Curtis; Musani, Altaf Sadrudin; Date, Kashmira

    2017-01-01

    During November–December 2015, as part of the 2015 cholera outbreak response in Iraq, the Iraqi Ministry of Health targeted ≈255,000 displaced persons >1 year of age with 2 doses of oral cholera vaccine (OCV). All persons who received vaccines were living in selected refugee camps, internally displaced persons camps, and collective centers. We conducted a multistage cluster survey to obtain OCV coverage estimates in 10 governorates that were targeted during the campaign. In total, 1,226 household and 5,007 individual interviews were conducted. Overall, 2-dose OCV coverage in the targeted camps was 87% (95% CI 85%–89%). Two-dose OCV coverage in the 3 northern governorates (91%; 95% CI 87%–94%) was higher than that in the 7 southern and central governorates (80%; 95% CI 77%–82%). The experience in Iraq demonstrates that OCV campaigns can be successfully implemented as part of a comprehensive response to cholera outbreaks among high-risk populations in conflict settings. PMID:27983502

  14. Oral Cholera Vaccine Coverage during an Outbreak and Humanitarian Crisis, Iraq, 2015.

    Science.gov (United States)

    Lam, Eugene; Al-Tamimi, Wasan; Russell, Steven Paul; Butt, Muhammad Obaid-Ul Islam; Blanton, Curtis; Musani, Altaf Sadrudin; Date, Kashmira

    2017-01-01

    During November-December 2015, as part of the 2015 cholera outbreak response in Iraq, the Iraqi Ministry of Health targeted ≈255,000 displaced persons >1 year of age with 2 doses of oral cholera vaccine (OCV). All persons who received vaccines were living in selected refugee camps, internally displaced persons camps, and collective centers. We conducted a multistage cluster survey to obtain OCV coverage estimates in 10 governorates that were targeted during the campaign. In total, 1,226 household and 5,007 individual interviews were conducted. Overall, 2-dose OCV coverage in the targeted camps was 87% (95% CI 85%-89%). Two-dose OCV coverage in the 3 northern governorates (91%; 95% CI 87%-94%) was higher than that in the 7 southern and central governorates (80%; 95% CI 77%-82%). The experience in Iraq demonstrates that OCV campaigns can be successfully implemented as part of a comprehensive response to cholera outbreaks among high-risk populations in conflict settings.

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

    Science.gov (United States)

    Haley, Bradd J; Choi, Seon Young; Grim, Christopher J; Onifade, Tiffiani J; Cinar, Hediye N; Tall, Ben D; Taviani, Elisa; Hasan, Nur A; Abdullah, Abdulshakur H; Carter, Laurenda; Sahu, Surasri N; Kothary, Mahendra H; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A; Huq, Anwar; Colwell, Rita R

    2014-01-01

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

  16. Cholera outbreaks (2012) in three districts of Nepal reveal clonal transmission of multi-drug resistant Vibrio cholerae O1.

    Science.gov (United States)

    Dixit, Sameer M; Johura, Fatema-Tuz; Manandhar, Sulochana; Sadique, Abdus; Rajbhandari, Rajesh M; Mannan, Shahnewaj B; Rashid, Mahamud-Ur; Islam, Saiful; Karmacharya, Dibesh; Watanabe, Haruo; Sack, R Bradley; Cravioto, Alejandro; Alam, Munirul

    2014-07-15

    Although endemic cholera causes significant morbidity and mortality each year in Nepal, lack of information about the causal bacterium often hinders cholera intervention and prevention. In 2012, diarrheal outbreaks affected three districts of Nepal with confirmed cases of mortality. This study was designed to understand the drug response patterns, source, and transmission of Vibrio cholerae associated with 2012 cholera outbreaks in Nepal. V. cholerae (n = 28) isolated from 2012 diarrhea outbreaks {n = 22; Kathmandu (n = 12), Doti (n = 9), Bajhang (n = 1)}, and surface water (n = 6; Kathmandu) were tested for antimicrobial response. Virulence properties and DNA fingerprinting of the strains were determined by multi-locus genetic screening employing polymerase chain reaction, DNA sequencing, and pulsed-field gel electrophoresis (PFGE). All V. cholerae strains isolated from patients and surface water were confirmed to be toxigenic, belonging to serogroup O1, Ogawa serotype, biotype El Tor, and possessed classical biotype cholera toxin (CTX). Double-mismatch amplification mutation assay (DMAMA)-PCR revealed the V. cholerae strains to possess the B-7 allele of ctx subunit B. DNA sequencing of tcpA revealed a point mutation at amino acid position 64 (N → S) while the ctxAB promoter revealed four copies of the tandem heptamer repeat sequence 5'-TTTTGAT-3'. V. cholerae possessed all the ORFs of the Vibrio seventh pandemic island (VSP)-I but lacked the ORFs 498-511 of VSP-II. All strains were multidrug resistant with resistance to trimethoprim-sulfamethoxazole (SXT), nalidixic acid (NA), and streptomycin (S); all carried the SXT genetic element. DNA sequencing and deduced amino acid sequence of gyrA and parC of the NAR strains (n = 4) revealed point mutations at amino acid positions 83 (S → I), and 85 (S → L), respectively. Similar PFGE (NotI) pattern revealed the Nepalese V. cholerae to be clonal, and related closely with V. cholerae associated with cholera in

  17. Genomic and Phenotypic Characterization of Vibrio cholerae Non-O1 Isolates from a US Gulf Coast Cholera Outbreak

    Science.gov (United States)

    Grim, Christopher J.; Onifade, Tiffiani J.; Cinar, Hediye N.; Tall, Ben D.; Taviani, Elisa; Hasan, Nur A.; Abdullah, AbdulShakur H.; Carter, Laurenda; Sahu, Surasri N.; Kothary, Mahendra H.; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A.; Huq, Anwar; Colwell, Rita R.

    2014-01-01

    Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally. PMID:24699521

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

    Directory of Open Access Journals (Sweden)

    Bradd J Haley

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

  19. Recovery of consciousness in hogs stunned with CO2: physiological responses.

    Science.gov (United States)

    Bolaños-López, D; Mota-Rojas, D; Guerrero-Legarreta, I; Flores-Peinado, S; Mora-Medina, P; Roldan-Santiago, P; Borderas-Tordesillas, F; García-Herrera, R; Trujillo-Ortega, M; Ramírez-Necoechea, R

    2014-10-01

    The objective of the present study was to determine the impact of recovering consciousness on physiological responses in hogs stunned with different concentrations of CO2. A total of 1336 pigs were moved into a CO2 anaesthesia chamber for 90s. The remaining pigs were assigned to 3 groups according to the CO2 concentration used for stunning: 85, 90 or 95%. Each group was then further divided into 2 sub-groups: those exsanguinated during the first 60s after leaving the chamber without recovering consciousness (WRC); and those exsanguinated after more than 60s that recovered consciousness (RC). The blood pH of the RC pigs decreased below 7.08, but their blood levels of Ca(2+) (>1.59mmol/L), glucose (>159.79mg/dL), and lactate (>103.52mg/dL) all increased when compared to reference values (RV) (Pconsciousness. In conclusion, exsanguination should be performed immediately upon the pigs leaving the CO2 chamber. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Interaction of PLP with GFP-MAL2 in the human oligodendroglial cell line HOG.

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    Raquel Bello-Morales

    Full Text Available The velocity of the nerve impulse conduction of vertebrates relies on the myelin sheath, an electrically insulating layer that surrounds axons in both the central and peripheral nervous systems, enabling saltatory conduction of the action potential. Oligodendrocytes are the myelin-producing glial cells in the central nervous system. A deeper understanding of the molecular basis of myelination and, specifically, of the transport of myelin proteins, will contribute to the search of the aetiology of many dysmyelinating and demyelinating diseases, including multiple sclerosis. Recent investigations suggest that proteolipid protein (PLP, the major myelin protein, could reach myelin sheath by an indirect transport pathway, that is, a transcytotic route via the plasma membrane of the cell body. If PLP transport relies on a transcytotic process, it is reasonable to consider that this myelin protein could be associated with MAL2, a raft protein essential for transcytosis. In this study, carried out with the human oligodendrocytic cell line HOG, we show that PLP colocalized with green fluorescent protein (GFP-MAL2 after internalization from the plasma membrane. In addition, both immunoprecipitation and immunofluorescence assays, indicated the existence of an interaction between GFP-MAL2 and PLP. Finally, ultrastructural studies demonstrated colocalization of GFP-MAL2 and PLP in vesicles and tubulovesicular structures. Taken together, these results prove for the first time the interaction of PLP and MAL2 in oligodendrocytic cells, supporting the transcytotic model of PLP transport previously suggested.

  1. Coupled Wave Energy and Erosion Dynamics along a Salt Marsh Boundary, Hog Island Bay, Virginia, USA

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    Anthony M. Priestas

    2015-09-01

    Full Text Available The relationship between lateral erosion of salt marshes and wind waves is studied in Hog Island Bay, Virginia USA, with high-resolution field measurements and aerial photographs. Marsh retreat is compared to wave climate calculated in the bay using the spectral wave-model Simulating Waves Nearshore (SWAN. We confirm the existence of a linear relationship between long-term salt marsh erosion and wave energy, and show that wave power can serve as a good proxy for average salt-marsh erosion rates. At each site, erosion rates are consistent across several temporal scales, ranging from months to decades, and are strongly related to wave power. On the contrary, erosion rates vary in space and weakly depend on the spatial distribution of wave energy. We ascribe this variability to spatial variations in geotechnical, biological, and morphological marsh attributes. Our detailed field measurements indicate that at a small spatial scale (tens of meters, a positive feedback between salt marsh geometry and wave action causes erosion rates to increase with boundary sinuosity. However, at the scale of the entire marsh boundary (hundreds of meters, this relationship is reversed: those sites that are more rapidly eroding have a marsh boundary which is significantly smoother than the marsh boundary of sheltered and slowly eroding marshes.

  2. Macelignan inhibits bee pathogenic fungi Ascophaera apis growth through HOG1 pathway

    Directory of Open Access Journals (Sweden)

    Y.K. Shin

    2016-01-01

    Full Text Available Ascosphaera apis is a bee pathogen that causes bee larvae infection disease, to which treatment is not yet well investigated. The aim of this study was to investigate antifungal susceptibility in vitro against A. apis and to identify a new antifungal agent for this pathogen through minimal inhibitory concentration (MIC assay and western blot analysis. Macelignan had 1.56 and 3.125 μg/mL MIC against A. apis after 24 and 48 h, respectively, exhibiting the strongest growth inhibition against A. apis among the tested compounds (corosolic acid, dehydrocostus lactone, loganic acid, tracheloside, fangchinoline and emodin-8-O-β-D-glucopyranoside. Furthermore, macelignan showed a narrow-ranged spectrum against various fungal strains without any mammalian cell cytotoxicity. In spite of miconazole having powerful broad-ranged anti-fungal activity including A. apis, it demonstrated strong cytotoxicity. Therefore, even if macelignan alone was effective as an antifungal agent to treat A. apis, combined treatment with miconazole was more useful to overcome toxicity, drug resistance occurrence and cost effectiveness. Finally, HOG1 was revealed as a target molecule of macelignan in the anti-A. apis activity by inhibiting phosphorylation using S. cerevisiae as a model system. Based on our results, macelignan, a food-grade antimicrobial compound, would be an effective antifungal agent against A. apis infection in bees.

  3. Comparative microscopy study of Vibrio cholerae flagella

    Science.gov (United States)

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

    1999-06-01

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

  4. Cholera: a continuous epidemic in Africa.

    Science.gov (United States)

    Naidoo, A; Patric, K

    2002-06-01

    Cholera continues to plague many parts of the world, but has largely been concentrated in Africa, which contributes more than 80% of the total cases worldwide. Natural disasters, like the 2000 floods in Mozambique and the volcanic eruption in the Democratic Republic of the Congo in 2002, generally lead to new outbreaks of the disease. The refugee problem in many countries throughout the world also causes potential threats for disease outbreaks. Case fatality rates are high, and we are not anywhere near curbing new cholera epidemics, especially in Africa. It is thus imperative to renew discussions about the nature of this deadly disease, its treatment, measures for prevention and control, modes of transmission, its physical, social and economic impact, and potential solutions.

  5. Catechol Siderophore Transport by Vibrio cholerae

    OpenAIRE

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

    2015-01-01

    Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses the catechol siderophore vibriobactin and also uses siderophores secreted by other species, including enterobactin produced by Escherichia coli. E. coli secretes both canonical cyclic enterobactin and linear enterobactin derivatives likely derived from its cleavage by the enterobactin esterase Fes. We show here that V....

  6. Origins of the current seventh cholera pandemic.

    Science.gov (United States)

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

    2016-11-29

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

  7. Central role of the Na(+)-translocating NADH:quinone oxidoreductase (Na(+)-NQR) in sodium bioenergetics of Vibrio cholerae.

    Science.gov (United States)

    Steuber, Julia; Halang, Petra; Vorburger, Thomas; Steffen, Wojtek; Vohl, Georg; Fritz, Günter

    2014-12-01

    Vibrio cholerae is a Gram-negative bacterium that lives in brackish or sea water environments. Strains of V. cholerae carrying the pathogenicity islands infect the human gut and cause the fatal disease cholera. Vibrio cholerae maintains a Na(+) gradient at its cytoplasmic membrane that drives substrate uptake, motility, and efflux of antibiotics. Here, we summarize the major Na(+)-dependent transport processes and describe the central role of the Na(+)-translocating NADH:quinone oxidoreductase (Na(+)-NQR), a primary Na(+) pump, in maintaining a Na(+)-motive force. The Na(+)-NQR is a membrane protein complex with a mass of about 220 kDa that couples the exergonic oxidation of NADH to the transport of Na(+) across the cytoplasmic membrane. We describe the molecular architecture of this respiratory complex and summarize the findings how electron transport might be coupled to Na(+)-translocation. Moreover, recent advances in the determination of the three-dimensional structure of this complex are reported.

  8. Activation of cholera toxin production by anaerobic respiration of trimethylamine N-oxide in Vibrio cholerae.

    Science.gov (United States)

    Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-Il; Yoon, Sang Sun

    2012-11-16

    Vibrio cholerae is a gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2',7'-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor.

  9. CHOLERA EL-TOR EN IRAN

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    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

  10. 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.

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

    Science.gov (United States)

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

    2016-08-05

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

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

    Science.gov (United States)

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

    2009-02-01

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

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

    Science.gov (United States)

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

    2013-08-29

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

  14. Risk Factors for Sustained Cholera Transmission, Juba County, South Sudan, 2014.

    Science.gov (United States)

    Ujjiga, Thomas T A; Wamala, Joseph F; Mogga, Juma J H; Othwonh, Thabo O; Mutonga, David; Kone-Coulibaly, Asta; Shaikh, Masood Ali; Mpairwe, Allan M; Abdinasir, Abubaker; Abdi, Mohamed A; Yoti, Zabulon; Olushayo, Olu; Nyimol, Pinyi; Lul, Riek; Lako, Richard L; Rumunu, John

    2015-10-01

    We conducted a case-control study to identify risk factors for the 2014 cholera outbreak in Juba County, South Sudan. Illness was associated with traveling or eating away from home; treating drinking water and receiving oral cholera vaccination were protective. Oral cholera vaccination should be used to complement cholera prevention efforts.

  15. Multidrug-Resistant Vibrio cholerae O1 was Responsible for a Cholera Outbreak in 2013 in Bagalkot, North Karnataka.

    Science.gov (United States)

    Bhattacharya, Debdutta; Dey, Shuchismita; Roy, Subarna; Parande, Mahantesh V; Telsang, M; Seema, M H; Parande, Aisha V; Mantur, Basappa G

    2015-01-01

    Cholera is a major cause of illness in the developing world. During the monsoon season, small sporadic clusters of cholera cases are reported on an annual basis in Karnataka, India. During the monsoons of 2013, there was a cholera outbreak in Badami, a remote area of Bagalkot district in Karnataka. The multi-drug-resistant Vibrio cholerae O1 serotype Ogawa was found to be responsible for this outbreak. On 5 August 2013, a 30-year-old woman presented with severe dehydration and watery diarrhea at the Aganwadi Health Centre in Badami. A total of 49 suspected cholera cases were reported, with an attack rate of 3.5%. The V. cholerae isolates exhibited resistance to a wide range of drugs, including ampicillin, co-trimoxazole, nitrofurantoin, carbenicillin, and third generation cephalosporins, and showed reduced susceptibility to third generation fluoroquinolones. All of the cephalosporin-resistant V. cholerae strains produced extended-spectrum beta-lactamase. All V. cholerae O1 isolates harbored virulent genes (ctxA, ctxB, tcpA El Tor, Tox S, VPI, ToxT, ToxR, ToxRS, ace, zot, and tcpP) and were found to be genetically similar as determined by randomly amplified polymorphic DNA fingerprinting assay. To the best of our knowledge, this is the first report of a cholera outbreak in the district of Bagalkot. The resistance of V. cholerae to commonly used antimicrobial drugs is becoming a major public health concern in the region as clinicians are left with a limited choice of antibiotics for the treatment of cholera.

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

    Directory of Open Access Journals (Sweden)

    Raikamal Ghosh

    2016-08-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  18. [Improvement of laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera Vibrio biovar El Tor].

    Science.gov (United States)

    Savel'eva, I V; Khatsukov, K X; Savel'eva, E I; Moskvitina, S I; Kovalev, D A; Savel'ev, V N; Kulichenko, A N; Antonenko, A D; Babenyshev, B V

    2015-01-01

    Improvement of laboratory diagnostics of cholera taking into the account appearance of hybrid variants of cholera vibrio El Tor biovar in the 1990s. Phenotypic and molecular-genetic properties of typical toxigenic (151 strains) and hybrid (102 strains) variants of El Tor biovar cholera vibrios, isolated in the Caucuses in 1970-1990 and 1993-1998, respectively, were studied. Toxigenicity gene DNA fragments, inherent to El Tor biovars or classic, were detected by using a reagent kit "Genes of Vibrio cholerae variant ctxB-rstR-rstC, REF" developed by us. Reagent kit "Genes of V. cholerae variant ctxB-rstR-rstC, REF" is proposed to be used for laboratory diagnostics of cholera during study of material from humans or environmental objects and for identification of V. cholerae 01 on genome level in PCR-analysis as a necessary addition to the classic scheme of bacteriological analysis. Laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera vibrio El Tor biovar is based on a complex study of material from humans and environmental objects by routine bacteriologic and PCR-analysis methods with the aim of detection of gene DNA fragments in the studied material, that determine biovar (classic or El Tor), identification of V. cholerae O1 strains with differentiation of El Tor vibrios into typical and altered, as well as determination of enterotoxin, produced by the specific cholera vibrio strain (by the presence ctxB(El) or ctxB(Cl) gene DNA fragment, coding biosynthesis of CT-2 or CT-1, respectively).

  19. Understanding the Hydrology of Cholera in South Asia

    Science.gov (United States)

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

    2007-12-01

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

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

    Science.gov (United States)

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

    2011-12-01

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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  2. Genome sequence of the human pathogen Vibrio cholerae Amazonia.

    NARCIS (Netherlands)

    Thompson, C.C.; Marin, M.A.; Dias, G.M.; Dutilh, B.E.; Edwards, R.A.; Iida, T.; Thompson, F.L.; Vicente, A.C.

    2011-01-01

    Vibrio cholerae O1 Amazonia is a pathogen that was isolated from cholera-like diarrhea cases in at least two countries, Brazil and Ghana. Based on multilocus sequence analysis, this lineage belongs to a distinct profile compared to strains from El Tor and classical biotypes. The genomic analysis rev

  3. Comparison of various modelling approaches applied to cholera case data

    CSIR Research Space (South Africa)

    Van Den Bergh, F

    2008-06-01

    Full Text Available The application of a methodology that proposes the use of spectral methods to inform the development of statistical forecasting models for cholera case data is explored in this paper. The seasonal behaviour of the target variable (cholera cases...

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  5. Genome sequence of the human pathogen Vibrio cholerae Amazonia.

    NARCIS (Netherlands)

    Thompson, C.C.; Marin, M.A.; Dias, G.M.; Dutilh, B.E.; Edwards, R.A.; Iida, T.; Thompson, F.L.; Vicente, A.C.

    2011-01-01

    Vibrio cholerae O1 Amazonia is a pathogen that was isolated from cholera-like diarrhea cases in at least two countries, Brazil and Ghana. Based on multilocus sequence analysis, this lineage belongs to a distinct profile compared to strains from El Tor and classical biotypes. The genomic analysis

  6. Occurrence of Vibrio cholerae in water reservoirs of Burkina Faso.

    Science.gov (United States)

    Kaboré, Saidou; Cecchi, Philippe; Mosser, Thomas; Toubiana, Mylène; Traoré, Oumar; Ouattara, Aboubakar S; Traoré, Alfred S; Barro, Nicolas; Colwell, Rita R; Monfort, Patrick

    2017-09-06

    Africa is currently an important region in which cholera epidemics occur. Little is known about the presence of Vibriocholerae in freshwater bodies in Africa. There are ca. 1700 lakes and reservoirs in Burkina Faso, most of which have been built within recent decades to secure water resources. The purpose of this study was to investigate the presence of V. cholerae in the water of reservoirs, using the most-probable-number polymerase chain reaction. Results showed that V. cholerae could be detected in water samples collected from 14 of 39 sampled reservoirs. The concentrations varied from 0 MPN/l to more than 1100 MPN/l. Fifty strains of V. cholerae isolated on CHROMagar™ vibrio were identified as V. cholerae non-O1/non-O139, none of which carried the ctxA gene. A significant positive correlation was found between the presence of V. cholerae in the reservoirs and both alkaline pH and phytoplankton biomass. V. cholerae was present in significantly higher numbers in reservoirs of urban areas than in rural areas. Since V. cholerae non-O1/non-O139 has been shown to be a causative agent of endemic diarrheal outbreaks, their presence in Burkina Faso reservoirs suggests they may play a role in gastroenteritis in that country. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  7. Malonate inhibits virulence gene expression in Vibrio cholerae.

    Science.gov (United States)

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

    2013-01-01

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

  8. Episode resembling immune complex disease after cholera vaccination

    OpenAIRE

    Mall, Thomas; Gyr, Klaus

    2017-01-01

    The case of a 25-year-old patient is reported who suffered from a syndrome similar to immune complex disease following cholera revaccination. The clinical picture included fever, muscle, joint and abdominal pain, vomiting, serositis, hepatitis, suspected myocarditis, anaemia and thrombocytopenia. Clinical symptoms subsided spontaneously within two weeks. This case illustrates a hazard of cholera vaccination so far not reported in the literature

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

    Directory of Open Access Journals (Sweden)

    Murad Lesmana

    2012-09-01

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

  10. 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.

  11. Zebrafish as a Natural Host Model for Vibrio cholerae Colonization and Transmission

    Science.gov (United States)

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

    2014-01-01

    The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival. PMID:24375135

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

    Science.gov (United States)

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

    2014-03-01

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

  13. Evolution of hedgehog and hedgehog-related genes, their origin from Hog proteins in ancestral eukaryotes and discovery of a novel Hint motif

    Directory of Open Access Journals (Sweden)

    Bürglin Thomas R

    2008-03-01

    Full Text Available Abstract Background The Hedgehog (Hh signaling pathway plays important roles in human and animal development as well as in carcinogenesis. Hh molecules have been found in both protostomes and deuterostomes, but curiously the nematode Caenorhabditis elegans lacks a bona-fide Hh. Instead a series of Hh-related proteins are found, which share the Hint/Hog domain with Hh, but have distinct N-termini. Results We performed extensive genome searches of the cnidarian Nematostella vectensis and several nematodes to gain further insights into Hh evolution. We found six genes in N. vectensis with a relationship to Hh: two Hh genes, one gene with a Hh N-terminal domain fused to a Willebrand factor type A domain (VWA, and three genes containing Hint/Hog domains with distinct novel N-termini. In the nematode Brugia malayi we find the same types of hh-related genes as in C. elegans. In the more distantly related Enoplea nematodes Xiphinema and Trichinella spiralis we find a bona-fide Hh. In addition, T. spiralis also has a quahog gene like C. elegans, and there are several additional hh-related genes, some of which have secreted N-terminal domains of only 15 to 25 residues. Examination of other Hh pathway components revealed that T. spiralis - like C. elegans - lacks some of these components. Extending our search to all eukaryotes, we recovered genes containing a Hog domain similar to Hh from many different groups of protists. In addition, we identified a novel Hint gene family present in many eukaryote groups that encodes a VWA domain fused to a distinct Hint domain we call Vint. Further members of a poorly characterized Hint family were also retrieved from bacteria. Conclusion In Cnidaria and nematodes the evolution of hh genes occurred in parallel to the evolution of other genes that contain a Hog domain but have different N-termini. The fact that Hog genes comprising a secreted N-terminus and a Hog domain are also found in many protists suggests that this

  14. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

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

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

  15. epidemiological and Clinical Characteristics of 28 cases of Cholera

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  17. Gastric emptying of oral rehydration solutions in acute cholera.

    Science.gov (United States)

    Collins, B J; Van Loon, F P; Molla, A; Molla, A M; Alam, N H

    1989-08-01

    Gastric emptying of rice powder electrolyte solution and of glucose electrolyte solution was measured by a marker dilution double sampling technique in 14 and in 16 adult patients respectively after intravenous rehydration during an attack of acute cholera. Six patients who received rice powder electrolyte solution and seven who received glucose electrolyte solution re-attended for a repeat study with the same test meal 16 days later, when fully recovered from cholera. No differences in gastric emptying patterns of the two electrolyte solutions were observed, either in the acute or in the recovered patients. Similarly, gastric emptying of both solutions was rapid during acute cholera and comparable to that observed in recovered patients. This study indicates that gastric emptying is not impaired in acute cholera and that the rate of emptying of oral rehydration solutions is adequate to account for their observed clinical efficacy in fast purging patients with acute cholera.

  18. Living in Living Cities

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    This paper presents and overview of current and potential applications of living technology to urban problems. Living technology can be described as technology that exhibits the core features of living systems. These features can be useful to solve dynamic problems. In particular, urban problems concerning mobility, logistics, telecommunications, governance, safety, sustainability, and society and culture are presented, while solutions involving living technology are reviewed. Finally, the usefulness of describing cities as living systems is discussed.

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

    Science.gov (United States)

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

    2016-08-01

    Cholera remains to be an international threat, with high rates of illness and death. In 2012 and 2013, two cholera outbreak happened in Iran, affecting lots of people. Vibrio cholerae O1 was confirmed as the etiological agent. Source identification and controlling the spread of the cholera disease are two critical approaches in cholera outbreaks. In this study, thirty V. cholerae O1 isolates were selected and has been evaluated for antimicrobial resistant as well as molecular typing by multilocus variable-number tandem-repeat analysis (MLVA) method. Twenty-nine (97%) isolates were sero-grouped as El Tor (one isolate was classical) and 100% were related to Inaba serotype. All of the isolates were susceptible to ciprofloxacin, chloramphenicol, ampicillin and gentamicin. On the other hand, 60% of the isolates were MDR (resistant to 3 or more classes). There were three resistance patterns. The most prevalent pattern was resistance to streptomycin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline (ST-SXT-E-T) which was seen in 50% of isolates. Using MLVA method 14 MLVA types were identified. MLVA type 2 (5-7-7-16-15) accounted for 43% of isolates. Isolates with the same genotype often did not have the same antibiogram. Overall, the data indicate that the Iranian V. cholerae were MDR and clonaly related. Furthermore, the results of this study shows that MLVA can be used as useful method for V. cholerae genotyping in epidemiological investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  2. Occurrence of methicillin-resistant Staphylococcus aureus in surface waters near industrial hog operation spray fields.

    Science.gov (United States)

    Hatcher, S M; Myers, K W; Heaney, C D; Larsen, J; Hall, D; Miller, M B; Stewart, J R

    2016-09-15

    Industrial hog operations (IHOs) have been identified as a source of antibiotic-resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). However, few studies have investigated the presence of antibiotic-resistant S. aureus in the environment near IHOs, specifically surface waters proximal to spray fields where IHO liquid lagoon waste is sprayed. Surface water samples (n=179) were collected over the course of approximately one year from nine locations in southeastern North Carolina and analyzed for the presence of presumptive MRSA using CHROMagar MRSA media. Culture-based, biochemical, and molecular tests, as well as matrix-assisted laser desorption/ionization-time of flight mass spectrometry were used to confirm that isolates that grew on CHROMagar MRSA media were S. aureus. Confirmed S. aureus isolates were then tested for susceptibility to 16 antibiotics and screened for molecular markers of MRSA (mecA, mecC) and livestock adaptation (absence of scn). A total of 12 confirmed MRSA were detected in 9 distinct water samples. Nine of 12 MRSA isolates were also multidrug-resistant (MDRSA [i.e., resistant to ≥3 antibiotic classes]). All MRSA were scn-positive and most (11/12) belonged to a staphylococcal protein A (spa) type t008, which is commonly associated with humans. Additionally, 12 confirmed S. aureus that were methicillin-susceptible (MSSA) were recovered, 7 of which belonged to spa type t021 and were scn-negative (a marker of livestock-adaptation). This study demonstrated the presence of MSSA, MRSA, and MDRSA in surface waters adjacent to IHO lagoon waste spray fields in southeastern North Carolina. To our knowledge, this is the first report of waterborne S. aureus from surface waters proximal to IHOs.

  3. Performance of the constructed wetland systems in pollutants removal from hog wastewater

    Directory of Open Access Journals (Sweden)

    Wallison da Silva Freitas

    2010-08-01

    Full Text Available The main objective of this work was to evaluate the efficiency of a constructed wetland systems (CWS for pollutants removal, in mono crop and multi crop with three different species of plants, originated from hog wastewater treatment (HW. Therefore, 5 CWS of 24.0 m x 1.1 m x 0.7 m were constructed, sealed with a membrane of polyvinyl chloride (PVC and filled with 0.4 m of small gravel. In CWS1, CWS2 and CWS3 grown to cattail (Typha latifolia L., Alternanthera philoxeroides (Mart. Griseb. and Tifton 85 grass (Cynodon dactylon Pers., respectively. In the bed of CWS4 was planted at 1st third Alternanthera, cattail, in the 2nd third and tifton-85 grass and in the 3rd third of. The CWS5 was not planted and it was used as control. After passing through a filter filled with crushed bagasse of sugar cane, the HW was applied to the CWS in a flow of 0.8 m3 d-1, which corresponded to a hydraulic detention time of 4.8 days. According to the results it was shown that the five CWS(s had statistically nearly the same removal of pollutants, and the average removal efficiency of TSS, COD, BOD and Zn, were 91, 89, 86 and 94%, respectively. Also high removals were obtained concerning the ST, N-total, NH4+ and P-total, with average values of 62, 59, 52 and 50%, respectively. The plants in all planted CWS worked in a similar way maintaining the system efficiency and the non cultivated CWS presented analogous capacity of pollutants removal when compared to the cultivated CWS(s.

  4. Ultra structure of the denervated vocal muscle mechanically in hogs (sus scrofa domestica

    Directory of Open Access Journals (Sweden)

    Leão, Henrique Zaquia

    2010-03-01

    Full Text Available Introduction: The literature is not clear in the ultra-structural manifestations of the vocal wrinkles after neural wound. Objective: To verify the alterations that occur in a vocal fold mechanically denervated. Method: In this prospective study, it were utilized 15 hogs of commercial race (Sus scrofa domesticates, with age of 4 to 12 weeks. The animals were distributed in three groups, chosen at random. Everybody was submitted to the denervation of the right vocal fold, with surgical removal of a segment with three centimeters of the recurring right laryngeal nerve. After 45, 90 and 180 days of the operations, it was proceeded the biopsy of the vocal muscles, it was prosecuted the samples for transmission electron microscopy and, for the ultra-structural study, utilized the transmission electron microscopy Philips, model EM208S. Results: The biopsied groups with 45 and 90 days after operation of mechanical denervation, presented disorganization miofibrilar, only vestigial lines Z in many samples, as well like altered mithochondrions presenting limited sizes, and matrix mithocondrial rarefied with rare mithocondrial cristae present. The biopsied group with 180 days after operation of denervation, presented regular sarcomeres, mithocondrions with sizes and regular number with correct positioning between the sarcomerical units. Conclusion: The finds in the ultra-structure of the vocal muscles suggest to re enervation of the muscle being that the muscular mithochondrions were the most sensible structures to the denervated condition, successions by the cytoarchiteture of the miofibrilas; the finds in the ultra-structure of the vocal muscles suggests to reinervation of the muscle in the period of approximately six months.

  5. 基于深度和局部 HOG 的交通车流监测研究%Traffic Car flow Monitor Research Based on Depth and Local HOG

    Institute of Scientific and Technical Information of China (English)

    兰岚; 徐阳

    2015-01-01

    针对交通车流监测问题,提出一种基于深度和局部 HOG 的交通车流监测算法,该算法首先将车辆的划分为9个特征区域,利用 HOG 算法对特征区域的图像进行数据化,构建一个车辆局部特征区域数据库;再利用 KPCA 算法对其进行降维,从而降低计算复杂度;最后利用随机森林对特征数据进行分类,从而得到分类器,完成车辆检测过程。结合 Kinect 的深度摄像功能,计算车辆特征区域距离交通信号灯的距离,进而完成车辆的监测。实验结果表明:算法较传统算法有更好的检测率,在交通车辆监测中有较高的监测准确率。%For the traffic car flow characteristic monitoring problem, a novel traffic car flow method based on depth and local HOG is proposed. Firstly, the car is divided into nine characteristic regions. The pixel value of car images can be converted into the data vectors, and the car characteristic data sets can be established by the local HOG. The dimensionality reduction of car characteristic data can be achieved by KPCA, and the computation complexity can be reduced. Secondly, the data classifier can be established by the results of the car characteristic data and the random forest. Finally, the car detection can be achieved. The distance between the characteristic regions and the traffic signals can be calculated by the Kinect, and the car flow monitoring can be achieved. A large number of experiments have been done. The results show that the proposed method not only has greater car detection results, but also has better monitoring accuracy rate in the car flow monitoring.

  6. Insights into Vibrio cholerae Intestinal Colonization from Monitoring Fluorescently Labeled Bacteria

    OpenAIRE

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

    2014-01-01

    Vibrio cholerae, the agent of cholera, is a motile non-invasive pathogen that colonizes the small intestine (SI). Most of our knowledge of the processes required for V. cholerae intestinal colonization is derived from enumeration of wt and mutant V. cholerae recovered from orogastrically infected infant mice. There is limited knowledge of the distribution of V. cholerae within the SI, particularly its localization along the villous axis, or of the bacterial and host factors that account for t...

  7. US Gulf-like toxigenic O1 Vibrio cholerae causing sporadic cholera outbreaks in China.

    Science.gov (United States)

    Luo, Yun; Octavia, Sophie; Jin, Dazhi; Ye, Julian; Miao, Ziping; Jiang, Tao; Xia, Shichang; Lan, Ruiting

    2016-05-01

    Cholera is potentially a life threatening disease caused by toxigenic Vibrio cholerae. Here we report the identification and characterisation of 76 non-7th pandemic clone O1 V. cholerae isolates including 65 clinical isolates from diarrhoeal patients from 2005 to 2014 in Zhejiang Province, China. We used multilocus sequence typing (MLST) to characterise 65 V. cholerae isolates. Pulse-Field Gel Electrophoresis (PFGE) was performed on a subset of the isolates and whole-genome sequencing was done on 13 isolates. MLST separated 65 isolates into 19 sequence types (STs). Thirty three isolates belonged to ST75 which also contains the US Gulf Coast clone. PFGE separated the 33 isolates into 16 pulsotypes. Whole genome sequencing of 10 ST75 isolates showed that the US Gulf Coast clone and the Chinese ST75 isolates can be separated into two distinct lineages, ST75a and ST75b. All Zhejiang ST75 isolates were ST75b. PFGE and genome sequencing confirmed the linked cases and identified small outbreaks caused by ST75b. The emergence and potential spread of ST75b may pose significant threat to public health. Epidemiological surveillance is required to further understand its epidemic potential. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  8. Cholera outbreak in South Africa, 2008-2009: laboratory analysis of Vibrio cholerae O1 strains.

    Science.gov (United States)

    Ismail, Husna; Smith, Anthony M; Tau, Nomsa P; Sooka, Arvinda; Keddy, Karen H

    2013-11-01

    A total of 720 Vibrio cholerae O1 strains were recovered for investigation from an outbreak of cholera in South Africa between November 2008 and April 2009. Strains were characterized by serotype testing. Antimicrobial susceptibility testing. Genetic diversity of 248 strains was investigated using pulsed-field gel electrophoresis (PFGE) analysis. Extended characterization was performed on 90 strains. Molecular analysis included: polymerase chain reaction (PCR) identification of ctxA and tcpA genes, sequencing the ctxAB gene, and investigation of molecular mechanisms conferring antimicrobial resistance. The majority of strains were characterized as serotype Ogawa. Strains showed multidrug resistance. Approximately 1.0% of strains displayed extended-spectrum β-lactamase (ESBL) activity. Strains showed very similar PFGE patterns. Ninety strains selected for extended characterization showed the following results: Strains possessed the cholera toxin (CT) and all were PCR positive for the tcpA-El Tor variant. Sequencing of the ctxB gene matched the B-1 allele. Strains harbored the SXT element. Strains that displayed ESBL activity possessed a 140-kilobase-pair plasmid that produced the TEM-63 β-lactamase. Nalidixic acid-resistant strains harbored mutations in GyrA (Ser83-Ile) and ParC (Ser85-Leu). These data highlight the rapid development of antimicrobial resistance and spread of V. cholerae O1 El Tor variants expressing the classical CT within South Africa.

  9. Pyrolysis of Woody Residue Feedstocks: Upgrading of Bio-Oils from Mountain-Pine-Beetle-Killed Trees and Hog Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Zacher, Alan H.; Elliott, Douglas C.; Olarte, Mariefel V.; Santosa, Daniel M.; Preto, Fernando; Iisa, Kristiina

    2014-12-01

    Liquid transportation fuel blend-stocks were produced by pyrolysis and catalytic upgrading of woody residue biomass. Mountain pine beetle killed wood and hog fuel from a saw mill were pyrolyzed in a 1 kg/h fluidized bed reactor and subsequently upgraded to hydrocarbons in a continuous fixed bed hydrotreater. Upgrading was performed by catalytic hydrotreatment in a two-stage bed at 170°C and 405°C with a per bed LHSV between 0.17 and 0.19. The overall yields from biomass to upgraded fuel were similar for both feeds: 24-25% despite the differences in bio-oil (intermediate) mass yield. Pyrolysis bio-oil mass yield was 61% from MPBK wood, and subsequent upgrading of the bio-oil gave an average mass yield of 41% to liquid fuel blend stocks. Hydrogen was consumed at an average of 0.042g/g of bio-oil fed, with final oxygen content in the product fuel ranging from 0.31% to 1.58% over the course of the test. Comparatively for hog fuel, pyrolysis bio-oil mass yield was lower at 54% due to inorganics in the biomass, but subsequent upgrading of that bio-oil had an average mass yield of 45% to liquid fuel, resulting in a similar final mass yield to fuel compared to the cleaner MPBK wood. Hydrogen consumption for the hog fuel upgrading averaged 0.041 g/g of bio-oil fed, and the final oxygen content of the product fuel ranged from 0.09% to 2.4% over the run. While it was confirmed that inorganic laded biomass yields less bio-oil, this work demonstrated that the resultant bio-oil can be upgraded to hydrocarbons at a higher yield than bio-oil from clean wood. Thus the final hydrocarbon yield from clean or residue biomass pyrolysis/upgrading was similar.

  10. Chloroform extract of hog barn dust modulates skeletal muscle ryanodine receptor calcium-release channel (RyR1)

    Science.gov (United States)

    Tian, Chengju; Shao, Chun Hong; Fenster, Danielle S.; Mixan, Mark; Romberger, Debra J.; Toews, Myron L.

    2010-01-01

    Skeletal muscle weakness is a reported ailment in individuals working in commercial hog confinement facilities. To date, specific mechanisms responsible for this symptom remain undefined. The purpose of this study was to assess whether hog barn dust (HBD) contains components that are capable of binding to and modulating the activity of type 1 ryanodine receptor Ca2+-release channel (RyR1), a key regulator of skeletal muscle function. HBD collected from confinement facilities in Nebraska were extracted with chloroform, filtered, and rotary evaporated to dryness. Residues were resuspended in hexane-chloroform (20:1) and precipitates, referred to as HBDorg, were air-dried and studied further. In competition assays, HBDorg dose-dependently displaced [3H]ryanodine from binding sites on RyR1 with an IC50 of 1.5 ± 0.1 μg/ml (Ki = 0.4 ± 0.0 μg/ml). In single-channel assays using RyR1 reconstituted into a lipid bilayer, HBDorg exhibited three distinct dose-dependent effects: first it increased the open probability of RyR1 by increasing its gating frequency and dwell time in the open state, then it induced a state of reduced conductance (55% of maximum) that was more likely to occur and persist at positive holding potentials, and finally it irreversibly closed RyR1. In differentiated C2C12 myotubes, addition of HBD triggered a rise in intracellular Ca2+ that was blocked by pretreatment with ryanodine. Since persistent activation and/or closure of RyR1 results in skeletal muscle weakness, these new data suggest that HBD is responsible, at least in part, for the muscle ailment reported by hog confinement workers. PMID:20576841

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

    Directory of Open Access Journals (Sweden)

    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

  12. Pregnancy Outcomes after a Mass Vaccination Campaign with an Oral Cholera Vaccine in Guinea: A Retrospective Cohort Study.

    Directory of Open Access Journals (Sweden)

    Lise Grout

    2015-12-01

    Full Text Available Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC, included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8 for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5 for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0 and 1.2% (0.0-2.5 in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818 or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314.In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a

  13. Pregnancy Outcomes after a Mass Vaccination Campaign with an Oral Cholera Vaccine in Guinea: A Retrospective Cohort Study

    Science.gov (United States)

    Grout, Lise; Martinez-Pino, Isabel; Ciglenecki, Iza; Keita, Sakoba; Diallo, Alpha Amadou; Traore, Balla; Delamou, Daloka; Toure, Oumar; Nicholas, Sarala; Rusch, Barbara; Staderini, Nelly; Serafini, Micaela; Grais, Rebecca F.; Luquero, Francisco J.

    2015-01-01

    Introduction Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2–36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women. Methods and Findings From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7–4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7–4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1–1.0) and 1.2% (0.0–2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5–2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13–1.91], p = 0.314). Conclusions In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or

  14. Sociocultural determinants of anticipated oral cholera vaccine acceptance in three African settings: a meta-analytic approach.

    Science.gov (United States)

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

    2016-01-14

    Controlling cholera remains a significant challenge in Sub-Saharan Africa. In areas where access to safe water and sanitation are limited, oral cholera vaccine (OCV) can save lives. Establishment of a global stockpile for OCV reflects increasing priority for use of cholera vaccines in endemic settings. Community acceptance of vaccines, however, is critical and sociocultural features of acceptance require attention for effective implementation. This study identifies and compares sociocultural determinants of anticipated OCV acceptance across populations in Southeastern Democratic Republic of Congo, Western Kenya and Zanzibar. Cross-sectional studies were conducted using similar but locally-adapted semistructured interviews among 1095 respondents in three African settings. Logistic regression models identified sociocultural determinants of OCV acceptance from these studies in endemic areas of Southeastern Democratic Republic of Congo (SE-DRC), Western Kenya (W-Kenya) and Zanzibar. Meta-analytic techniques highlighted common and distinctive determinants in the three settings. Anticipated OCV acceptance was high in all settings. More than 93% of community respondents overall indicated interest in a no-cost vaccine. Higher anticipated acceptance was observed in areas with less access to public health facilities. In all settings awareness of cholera prevention methods (safe food consumption and garbage disposal) and relating ingestion to cholera causation were associated with greater acceptance. Higher age, larger households, lack of education, social vulnerability and knowledge of oral rehydration solution for self-treatment were negatively associated with anticipated OCV acceptance. Setting-specific determinants of acceptance included reporting a reliable income (W-Kenya and Zanzibar, not SE-DRC). In SE-DRC, intention to purchase an OCV appeared unrelated to ability to pay. Rural residents were less likely than urban counterparts to accept an OCV in W-Kenya, but more

  15. Pregnancy Outcomes after a Mass Vaccination Campaign with an Oral Cholera Vaccine in Guinea: A Retrospective Cohort Study.

    Science.gov (United States)

    Grout, Lise; Martinez-Pino, Isabel; Ciglenecki, Iza; Keita, Sakoba; Diallo, Alpha Amadou; Traore, Balla; Delamou, Daloka; Toure, Oumar; Nicholas, Sarala; Rusch, Barbara; Staderini, Nelly; Serafini, Micaela; Grais, Rebecca F; Luquero, Francisco J

    2015-12-01

    Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women. From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0) and 1.2% (0.0-2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314). In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective

  16. Drug response and genetic properties of Vibrio cholerae associated with endemic cholera in north-eastern Thailand, 2003-2011.

    Science.gov (United States)

    Chomvarin, Chariya; Johura, Fatema-Tuz; Mannan, Shahnewaj B; Jumroenjit, Warin; Kanoktippornchai, Boonnapa; Tangkanakul, Waraluk; Tantisuwichwong, Napaporn; Huttayananont, Sriwanna; Watanabe, Haruo; Hasan, Nur A; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R; Alam, Munirul

    2013-04-01

    Cholera, caused by Vibrio cholerae, results in significant morbidity and mortality worldwide, including Thailand. Representative V. cholerae strains associated with endemic cholera (n = 32), including strains (n = 3) from surface water sources, in Khon Kaen, Thailand (2003-2011), were subjected to microbiological, molecular and phylogenetic analyses. According to phenotypic and related genetic data, all tested V. cholerae strains belonged to serogroup O1, biotype El Tor (ET), Inaba (IN) or Ogawa (OG). All of the strains were sensitive to gentamicin and ciprofloxacin, while multidrug-resistant (MDR) strains showing resistance to erythromycin, tetracycline, trimethoprim/sulfamethoxazole and ampicillin were predominant in 2007. V. cholerae strains isolated before and after 2007 were non-MDR. All except six diarrhoeal strains possessed ctxA and ctxB genes and were toxigenic altered ET, confirmed by MAMA-PCR and DNA sequencing. Year-wise data revealed that V. cholerae INET strains isolated between 2003 and 2004, plus one strain isolated in 2007, lacked the RS1 sequence (rstC) and toxin-linked cryptic plasmid (TLC)-specific genetic marker, but possessed CTX(CL) prophage genes ctxB(CL) and rstR(CL). A sharp genetic transition was noted, namely the majority of V. cholerae strains in 2007 and all in 2010 and 2011 were not repressor genotype rstR(CL) but instead were rstR(ET), and all ctx(+) strains possessed RS1 and TLC-specific genetic markers. DNA sequencing data revealed that strains isolated since 2007 had a mutation in the tcpA gene at amino acid position 64 (N→S). Four clonal types, mostly of environmental origin, including subtypes, reflected genetic diversity, while distinct signatures were observed for clonally related, altered ET from Thailand, Vietnam and Bangladesh, confirmed by distinct subclustering patterns observed in the PFGE (NotI)-based dendrogram, suggesting that endemic cholera is caused by V. cholerae indigenous to Khon Kaen.

  17. Drug response and genetic properties of Vibrio cholerae associated with endemic cholera in north-eastern Thailand, 2003–2011

    Science.gov (United States)

    Chomvarin, Chariya; Johura, Fatema-Tuz; Mannan, Shahnewaj B.; Jumroenjit, Warin; Kanoktippornchai, Boonnapa; Tangkanakul, Waraluk; Tantisuwichwong, Napaporn; Huttayananont, Sriwanna; Watanabe, Haruo; Hasan, Nur A.; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R.

    2013-01-01

    Cholera, caused by Vibrio cholerae, results in significant morbidity and mortality worldwide, including Thailand. Representative V. cholerae strains associated with endemic cholera (n = 32), including strains (n = 3) from surface water sources, in Khon Kaen, Thailand (2003–2011), were subjected to microbiological, molecular and phylogenetic analyses. According to phenotypic and related genetic data, all tested V. cholerae strains belonged to serogroup O1, biotype El Tor (ET), Inaba (IN) or Ogawa (OG). All of the strains were sensitive to gentamicin and ciprofloxacin, while multidrug-resistant (MDR) strains showing resistance to erythromycin, tetracycline, trimethoprim/sulfamethoxazole and ampicillin were predominant in 2007. V. cholerae strains isolated before and after 2007 were non-MDR. All except six diarrhoeal strains possessed ctxA and ctxB genes and were toxigenic altered ET, confirmed by MAMA-PCR and DNA sequencing. Year-wise data revealed that V. cholerae INET strains isolated between 2003 and 2004, plus one strain isolated in 2007, lacked the RS1 sequence (rstC) and toxin-linked cryptic plasmid (TLC)-specific genetic marker, but possessed CTXCL prophage genes ctxBCL and rstRCL. A sharp genetic transition was noted, namely the majority of V. cholerae strains in 2007 and all in 2010 and 2011 were not repressor genotype rstRCL but instead were rstRET, and all ctx+ strains possessed RS1 and TLC-specific genetic markers. DNA sequencing data revealed that strains isolated since 2007 had a mutation in the tcpA gene at amino acid position 64 (N→S). Four clonal types, mostly of environmental origin, including subtypes, reflected genetic diversity, while distinct signatures were observed for clonally related, altered ET from Thailand, Vietnam and Bangladesh, confirmed by distinct subclustering patterns observed in the PFGE (NotI)-based dendrogram, suggesting that endemic cholera is caused by V. cholerae indigenous to Khon Kaen. PMID:23319310

  18. Quantifying Vibrio cholerae enterotoxicity in a zebrafish infection model.

    Science.gov (United States)

    Mitchell, Kristie C; Breen, Paul; Britton, Sarah; Neely, Melody N; Withey, Jeffrey H

    2017-06-16

    Vibrio cholerae is the etiological agent of cholera, an acute intestinal infection in humans characterized by voluminous watery diarrhea. Cholera is spread through ingestion of contaminated food or water, primarily in developing countries that lack the proper infrastructure for proper water and sewage treatment. Vibrio cholerae is an aquatic bacterium that inhabits coastal and estuarine areas, and is known to have several environmental reservoirs, including fish. Our laboratory has recently described the use of the zebrafish as a new animal model for the study of V. cholerae intestinal colonization, pathogenesis, and transmission.As early as six hours after exposure to V. cholerae, zebrafish develop diarrhea. Prior work in our laboratory has shown that this is not due to the action of cholera toxin. We hypothesize that accessory toxins produced by V. cholerae are the cause of diarrhea in infected zebrafish. In order to assess the effects of accessory toxins in the zebrafish, it was necessary to develop a method of quantifying diarrheal volume as a measure of pathogenesis. Here, we have adapted cell density, protein, and mucin assays, along with enumeration of V. cholerae in the zebrafish intestinal tract and in the infection water, to achieve this goal. Combined, these assays should help us determine which toxins have the greatest diarrheagenic effect in fish, and consequently, which toxins may play a role in environmental transmission.Importance Identification of the accessory toxins that cause diarrhea in zebrafish can help us understand more about the role of fish in the wild as aquatic reservoirs for V. cholerae It is plausible that accessory toxins can act to prolong colonization and subsequent shedding of V. cholerae back into the environment, thus perpetuating and facilitating transmission during an outbreak. It is also possible that accessory toxins help to maintain low levels of intestinal colonization in fish, giving V. cholerae an advantage when

  19. Establishment of Experimental Murine Peritonitis Model with Hog Gastric Mucin for Carbapenem-Resistant Gram-Negative Bacteria

    Science.gov (United States)

    Park, Chulmin; Chun, Hye-Sun; Byun, Ji-Hyun; Cho, Sung-Yeon

    2017-01-01

    Animal models are essential to studies of infectious diseases. The use of mice to test bacterial infection has been extensively reported. However, methods applied to clinical isolates, particularly for carbapenem-resistant bacteria, must be tailored according to the infection models and bacteria used. In this study, we infected 6-week-old female BALB/c mice intraperitoneally with different strains of resistant bacteria plus 3% hog gastric mucin. This method was found to be efficient and readily applicable for investigation of carbapenem-resisant Gram-negative pathogens (e.g., Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) detected in Korea.

  20. Flexibility of oral cholera vaccine dosing-a randomized controlled trial measuring immune responses following alternative vaccination schedules in a cholera hyper-endemic zone

    National Research Council Canada - National Science Library

    Kanungo, Suman; Desai, Sachin N; Nandy, Ranjan Kumar; Bhattacharya, Mihir Kumar; Kim, Deok Ryun; Sinha, Anuradha; Mahapatra, Tanmay; Yang, Jae Seung; Lopez, Anna Lena; Manna, Byomkesh; Bannerjee, Barnali; Ali, Mohammad; Dhingra, Mandeep Singh; Chandra, Ananga Mohan; Clemens, John D; Sur, Dipika; Wierzba, Thomas F

    2015-01-01

    A bivalent killed whole cell oral cholera vaccine has been found to be safe and efficacious for five years in the cholera endemic setting of Kolkata, India, when given in a two dose schedule, two weeks apart...

  1. Enumeration of viable non-culturable Vibrio cholerae using propidium monoazide combined with quantitative PCR.

    Science.gov (United States)

    Wu, Bin; Liang, Weili; Kan, Biao

    2015-08-01

    The well-known human pathogenic bacterium, Vibrio cholerae, can enter a physiologically viable but non-culturable (VBNC) state under stress conditions. The differentiation of VBNC cells and nonviable cells is essential for both disease prevention and basic research. Among all the methods for detecting viability, propidium monoazide (PMA) combined with real-time PCR is popular because of its specificity, sensitivity, and speed. However, the effect of PMA treatment is not consistent and varies among different species and conditions. In this study, with an initial cell concentration of 1×10(8) CFU/ml, time and dose-effect relationships of different PMA treatments were evaluated via quantitative real-time PCR using live cell suspensions, dead cell suspensions and VBNC cell suspensions of V. cholerae O1 El Tor strain C6706. The results suggested that a PMA treatment of 20 μM PMA for 20 min was optimal under our conditions. This treatment maximized the suppression of the PCR signal from membrane-compromised dead cells but had little effect on the signal from membrane-intact live cells. In addition to the characteristics of PMA treatment itself, the initial concentration of the targeted bacteria showed a significant negative influence on the stability of PMA-PCR assay in this study. We developed a strategy that mimicked a 1×10(8) CFU/ml cell concentration with dead bacteria of a different bacterial species, the DNA of which cannot be amplified using the real time PCR primers. With this strategy, our optimal approach successfully overcame the impact of low cell density and generated stable and reliable results for counting viable cells of V. cholerae in the VBNC state. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Fowl Cholera and Its Control Prospect With Locally isolated Pasteurella multocida Bivalent Vaccines

    Directory of Open Access Journals (Sweden)

    Tati Ariyanti

    2008-03-01

    Full Text Available Pasteurellosis or fowl cholera disease which associated with Pasteurella multocida group A and D infections occurred sporadically in many parts of the world, including in Indonesia. The pathogenic activity of P. multocida in chickens were based on lipopolysacharide (LPS antigens associated with group A and D capsules, and the resistance factor of complement mediated bacteriolysis in animals. In order to reduce common bacterial infections, antibiotics were routinely used as feed additive or by drinking water, but fowl cholera cases still occur. Fowl cholera control by vaccinations have been used more than a hundred years ago by means of inactive vaccine, but imported inactive vaccine was reported not effective due to lack of cross protection against heterologous serotype. At present, many local P. multocida isolates from chicken and ducks from many areas in Indonesia were characterised for their antigenicity, immunogenicity and prepared as monovalent or bivalent vaccine. Only the monovalent vaccine prepared from BCC 2331 or DY2 demonstrated the presence of immunoprotection against homologous and heterologous challenged with live bacteria. The prototype bivalent vaccine consisting of BCC 2331 + DY2 demonstrated high degree of cross protection against challenged individual with or mixed of BCC 2331 + DY2 at average of 60 – 75% and 75 – 100%, respectively. Monovalent and bivalent vaccine prepared from other isolates including imported reference strains of P. multocida demonstrated no protection in experimentally vaccinated ducks and chicken against challenged with live bacteria of neither BCC 2331 nor with DY2. From these retrospective studies, it was concluded that the local isolates P. multocida designated as BCC 2331 and DY2 could be used as candidates of prototype vaccine or master seed vaccine but their effectiveness still need to be evaluated under field conditions.

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

    Science.gov (United States)

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

    1984-09-01

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

  4. Cholera in India: an analysis of reports, 1997–2006

    Science.gov (United States)

    Kanungo, S; Sah, BK; Lopez, AL; Sung, JS; Paisley, AM; Sur, D; Clemens, JD

    2010-01-01

    Abstract Objective To more accurately define the annual incidence of cholera in India, believed to be higher than reported to the World Health Organization (WHO). Methods We searched the biomedical literature to extract data on the cases of cholera reported in India from 1997 to 2006 and compared the numbers found to those reported annually to WHO over the same period. The latter were obtained from WHO’s annual summaries of reported cholera cases and National health profile 2006, published by India’s Central Bureau of Health Intelligence. Findings Of India’s 35 states or union territories, 21 reported cholera cases during at least one year between 1997 and 2006. The state of West Bengal reported cases during all 10 years, while the state of Maharashtra and the union territory of Delhi reported cases during nine, and Orissa during seven. There were 68 outbreaks in 18 states, and 222 038 cases were detected overall. This figure is about six times higher than the number reported to WHO (37 783) over the same period. The states of Orissa, West Bengal, Andaman and Nicobar Islands, Assam and Chhattisgarh accounted for 91% of all outbreak-related cases. Conclusion The reporting of cholera cases in India is incomplete and the methods used to keep statistics on cholera incidence are inadequate. Although the data are sparse and heterogeneous, cholera notification in India is highly deficient. PMID:20428385

  5. Molecular tools in understanding the evolution of Vibrio cholerae

    Science.gov (United States)

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

    2015-01-01

    Vibrio cholerae, the etiological agent of cholera, has been a scourge for centuries. Cholera remains a serious health threat for developing countries and has been responsible for millions of deaths globally over the past 200 years. Identification of V. cholerae has been accomplished using a variety of methods, ranging from phenotypic strategies to DNA based molecular typing and currently whole genomic approaches. This array of methods has been adopted in epidemiological investigations, either singly or in the aggregate, and more recently for evolutionary analyses of V. cholerae. Because the new technologies have been developed at an ever increasing pace, this review of the range of fingerprinting strategies, their relative advantages and limitations, and cholera case studies was undertaken. The task was challenging, considering the vast amount of the information available. To assist the study, key references representative of several areas of research are provided with the intent to provide readers with a comprehensive view of recent advances in the molecular epidemiology of V. cholerae. Suggestions for ways to obviate many of the current limitations of typing techniques are also provided. In summary, a comparative report has been prepared that includes the range from traditional typing to whole genomic strategies. PMID:26500613

  6. Treatment of cholera-like diarrhoea with oral rehydration.

    Science.gov (United States)

    Atia, A; Buchman, A L

    2010-09-01

    Cholera diarrhoea remains a major global health problem that has caused seven pandemics. The pathogenesis of cholera is attributable to the production of cholera toxin by the causative pathogen, Vibrio cholerae. The toxin causes increased production of cyclic adenosine monophosphate and this results in massive water and electrolyte secretion into the intestinal lumen. These changes manifest clinically as the painless defecation of voluminous stools that resemble 'rice water', leading to severe dehydration. The cornerstone in the management of cholera diarrhoea is the use of oral rehydration solutions (ORS) to replace the water and electrolytes lost as stools. The World Health Organization recommends the use of ORS of 'reduced osmolarity' for the treatment of acute non-cholera diarrhoea and the use of rice-based ORS for the management of cholera diarrhoea. Although several attempts have been made to improve ORS, studies to evaluate some of the modifications, which include the addition of amylase-resistant starch, the use of amino acids (such as glycine, alanine and glutamine) as sodium cotransporters, and zinc-supplemented ORS, are still needed.

  7. Cholera - the new strike of an old foe.

    Science.gov (United States)

    Kuna, Anna; Gajewski, Michał

    2017-01-01

    Cholera is an acute bacterial gastrointestinal infection caused by ingestion of water or food containing the pathogen Vibrio cholerae. The incubation period can be very short and it takes between several hours and 5 days. During the 19th century, cholera was spreading from India across the world. Its original reservoir was located in the Ganges delta. So far, there have been six epidemics of cholera; the current outbreak is the seventh. It started in Asia, attacked Africa and then the Americas. Cholera causes thousands of illnesses and deaths annually, mostly in South Asia and Sub-Saharan Africa. The current outbreak began in Yemen in October 2016, it peaked in December with subsequent decline, then the epidemic has re-erupted in April 2017 and it still continues. It is currently the largest outbreak in the world, with 5000 new infections a day (as of August 19th, 2017 the number of cholera cases stands at 527,000 with 1997 deaths). The most common symptoms of the illness are diarrhoea, dehydration, vomiting, and abdominal cramps. Case-fatality rate is lower than 1%, if rehydration treatment is prescribed rapidly, but it can exceed 70% in patients not treated properly. Aggressive and rapid fluid repletion is the basis of treatment for cholera. In many cases, rehydration therapy, given orally or parenterally, is enough to rescue infected patients. Antibiotics, mainly fluoroquinolones, tetracyclines, and macrolides are an adjunctive therapy for patients with moderate to severe fluid loss.

  8. 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.

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Reduced osmolarity oral rehydration solution for treating cholera.

    Science.gov (United States)

    Murphy, C; Hahn, S; Volmink, J

    2004-10-18

    Oral rehydration solution (ORS) is used to treat dehydration caused by diarrheal diseases including cholera. Reduced osmolarity formulations are safe and more effective than standard ORS for treating non-cholera diarrhea. As cholera causes rapid electrolyte loss, it is important to know if these benefits are similar for people with cholera. To compare the safety and efficacy of reduced osmolarity oral rehydration solution (ORS) with standard ORS for treating diarrhea due to cholera. We searched the Cochrane Infectious Disease Group Specialized Register (January 2004), CENTRAL (The Cochrane Library Issue 1, 2004), MEDLINE (1966 to January 2004), EMBASE (1974 to January 2004), and LILACS (1982 to January 2004). We also contacted organizations and searched reference lists. Randomized controlled trials comparing reduced osmolarity ORS with standard ORS for treating adults and children with acute diarrhea due to cholera. Two reviewers independently applied eligibility criteria, assessed trial quality, and extracted data. We pooled binary data using relative risks (RR), continuous data using weighted mean difference (WMD) or the standardized mean difference (SMD), and presented the results with 95% confidence intervals (CI). For glucose-based reduced osmolarity ORS, seven trials (718 participants) met the inclusion criteria. Biochemical hyponatremia (serum sodium cholera, reduced osmolarity ORS is associated with biochemical hyponatremia when compared with standard ORS, although there are similar benefits in terms of other outcomes. Although this risk does not appear to be accompanied by serious consequences, the total patient experience in existing trials is small. Under wider practice conditions, especially where patient monitoring is difficult, caution is warranted.

  11. [Cholera epidemics in Mali between 1995 and 2004].

    Science.gov (United States)

    Dao, Sounkalo; Konaté, Issa; Oumar, Aboubacar Alassane; Sacko, Massambou; Maiga, Ibrahim; Toure, Kandioura; Diarra, Seydou; Bougoudogo, Flabou

    2009-01-01

    Cholera represents a public health problem in developing countries like Mali. This work aims to describe the characteristics of the cholera epidemics which occurred in Mali between 1995 and 2004. A retrospective survey was conducted within the Division of the fight against the diseases of epidemic potential and the Institute of Public Health and Research of the Ministry of Health of Mali. Individual medical records tracking the follow-up of patients as well as the registers of these structures were used as sources to collect data for the study. There were 12,176 cases of cholera recorded, including 1,406 deaths, from 1995 to 2004. Cholera outbreaks in Mali have been a regular occurrence every year since 2001. The regions of Mopti and Segou seem to be the most impacted by these epidemics. The lethal rates were higher than 1% at the time of each of these epidemics during this period. Vibrio cholerae O: 1, biotype El Tor were responsible for the epidemics, and the serotype Ogawa was prevalent. Cholera epidemics have been constant in Mali since the beginning of the 21st century in spite of the efforts which have been made to prevent and control them. A rigorous analysis of the factors which support this persistence and appropriate measures are essential to reverse cholera in this country.

  12. Survival of Vibrio cholerae O1 on fomites.

    Science.gov (United States)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Guillaume Constantin de Magny

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

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Ineffective Phosphorylation of Mitogen-Activated Protein Kinase Hog1p in Response to High Osmotic Stress in the Yeast Kluyveromyces lactis

    Science.gov (United States)

    Velázquez-Zavala, Nancy; Rodríguez-González, Miriam; Navarro-Olmos, Rocío; Ongay-Larios, Laura; Kawasaki, Laura; Torres-Quiroz, Francisco

    2015-01-01

    When treated with a hyperosmotic stimulus, Kluyveromyces lactis cells respond by activating the mitogen-activated protein kinase (MAPK) K. lactis Hog1 (KlHog1) protein via two conserved branches, SLN1 and SHO1. Mutants affected in only one branch can cope with external hyperosmolarity by activating KlHog1p by phosphorylation, except for single ΔKlste11 and ΔKlste50 mutants, which showed high sensitivity to osmotic stress, even though the other branch (SLN1) was intact. Inactivation of both branches by deletion of KlSHO1 and KlSSK2 also produced sensitivity to high salt. Interestingly, we have observed that in ΔKlste11 and ΔKlsho1 ΔKlssk2 mutants, which exhibit sensitivity to hyperosmotic stress, and contrary to what would be expected, KlHog1p becomes phosphorylated. Additionally, in mutants lacking both MAPK kinase kinases (MAPKKKs) present in K. lactis (KlSte11p and KlSsk2p), the hyperosmotic stress induced the phosphorylation and nuclear internalization of KlHog1p, but it failed to induce the transcriptional expression of KlSTL1 and the cell was unable to grow in high-osmolarity medium. KlHog1p phosphorylation via the canonical HOG pathway or in mutants where the SHO1 and SLN1 branches have been inactivated requires not only the presence of KlPbs2p but also its kinase activity. This indicates that when the SHO1 and SLN1 branches are inactivated, high-osmotic-stress conditions activate an independent input that yields active KlPbs2p, which, in turn, renders KlHog1p phosphorylation ineffective. Finally, we found that KlSte11p can alleviate the sensitivity to hyperosmotic stress displayed by a ΔKlsho1 ΔKlssk2 mutant when it is anchored to the plasma membrane by adding the KlSho1p transmembrane segments, indicating that this chimeric protein can substitute for KlSho1p and KlSsk2p. PMID:26150414

  16. 基于 Hog-MAPK 信号通路探讨白念珠菌氟康唑耐药机制的实验研究%A Study of fluconazole resistance mechanism of Candida albicans based on Hog-MAPK signal pathway

    Institute of Scientific and Technical Information of China (English)

    闻轶旸; 黄欣; 沈帅帅; 赵敬军

    2015-01-01

    目的:探讨 Hog-MAPK 信号通路在白念珠菌氟康唑耐药机制中的作用。方法通过 Real-Time PCR、Western blot 等方法比较白念珠菌氟康唑敏感株与耐药株 Hog-MAPK 信号通路相关的 HOG1等基因的 mRNA 表达,以及磷酸化p38 MAPK 蛋白表达的差异,并应用微量液基稀释法检测白念珠菌 HOG1基因缺陷株及其原始亲代菌株/标准株对氟康唑MIC 值的差异。结果白念珠菌氟康唑敏感株与耐药株之间 Hog-MAPK 信号通路相关基因 mRNA 表达和蛋白表达存在一定差异性,敏感株的表达在一定程度上低于耐药株,HOG1基因缺陷株对氟康唑更为敏感。结论白念珠菌氟康唑耐药性可能与 Hog-MAPK 信号通路中部分基因和蛋白表达有关,这些基因和蛋白表达的降低可能使耐药性发生改变。%Obejectives To investigate the role of Hog-MAPK signaling pathway in the fluconazole resistance mechanism of Candida albicans mechanism.Methods Using Real-Time PCR and Western blot to compare the expression of HOG1 gene and Phosphorylation p38 MAPK protein from Hog-MAPK signaling pathway in fluconazole sensitive strain and resistance strain,then dectect the fluconazole MIC of Candida albicans HOG1 mutant and its original parent strain/standard strain.Re-sults The difference of the expression of Hog-MAPK signaling pathway related gene and protein is found between Candida albicans fluconazole sensitive strain and resistant strain,the expression of sensitive strain is less than resistant strain to a cer-tain extent,and HOG1 mutant strain is more sensitive to fluconazole.Conclusion The fluconazole resistance mechanism of Candida albicans may be associated with some gene and protein from Hog-MAPK pathway.The decreased expression of these genes and proteins may cause change of resistance to fluconazole.

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

    Science.gov (United States)

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

    1987-06-01

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

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

    Science.gov (United States)

    Gańczak, Maria

    2014-01-01

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

  19. Pulmonary oedema associated with acidosis in patients with cholera.

    Science.gov (United States)

    Greenough, W B; Hirschhorn, N; Gordon, R S; Lindenbaum, J; Ally, K M

    1976-06-01

    Five patients with severe acidosis and pulmonary oedema complicating cholera were seen at the Cholera Research Laboratory, Dacca, in a two-year period. All had had inadequate treatment. Their disease resulted in acidosis prior to admission; only the two who subsequently survived received volumes of sodium bicarbonate solutions sufficiently large to repair completely their acidosis. Saline alone worsened pulmonary congestion, while alkali appeared to relieve it despite the accompanying volume expansion. These observations are consistent with the known redistribution of blood to the central circulation in acidosis. Timely and proper treatment of cholera will avert this syndrome, when use of isotonic sodium bicarbonate sufficient to correct acidosis may be very helpful.

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

    Directory of Open Access Journals (Sweden)

    Jacqueline Deen

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

  1. 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.

  2. In Vitro Inhibition of Cholera Toxin Production in Vibrio cholerae by Methanol Extract of Sweet Fennel Seeds and Its Components.

    Science.gov (United States)

    Chatterjee, Shruti; Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Chowdhury, Nityananda; Asakura, Masahiro; Hinenoya, Atsushi; Ramamurthy, T; Iwaoka, Emiko; Aoki, Shunji; Yamasaki, Shinji

    2016-09-21

    A newly emerged Vibrio cholerae O1 El Tor variant strain with multidrug resistance is considered a threat to public health. Recent strategies to suppress virulence factors production instead of bacterial growth may lead to less selective pressure for the emergence of resistant strains. The use of spices and their active constituents as the inhibitory agents against cholera toxin (CT) production in V. cholerae may be an alternative approach to treat cholera. In this study, we examined the potential of sweet fennel seed (Foeniculum vulgare Miller var. dulce) methanol extract to inhibit CT production in V. cholerae without affecting viability. The methanol extract of sweet fennel seeds significantly inhibited CT production in various V. cholerae strains, regardless of serogroup or biotype. Interestingly, trans-anethole and 4-allylanisole, essential oil components of sweet fennel seeds, also demonstrated similar effects. Here, we report that sub-bactericidal concentrations of sweet fennel seed methanol extract and its major components can drastically inhibit CT production in various V. cholerae strains.

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

    Science.gov (United States)

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

    1996-01-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    with the burden of disease from cholera in Tanzania and uses socioeconomic data to control for the impacts of general development on the risk of cholera. The results show a significant relationship between temperature and the incidence of cholera. For a 1 degree Celsius temperature increase the initial relative...... risk of cholera increases by 15 to 29 percent. Based on the modeling results, we project the number and costs of additional cases of cholera that can be attributed to climate change by 2030 in Tanzania for a 1 and 2 degree increase in temperatures, respectively. The total costs of cholera attributable...

  5. 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.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    African Journals Online (AJOL)

    DRINIE

    2004-01-01

    Jan 1, 2004 ... prepared in this manner for all the experiments. Baseline counts of ..... showed that sunlight induces propagation of this toxin-encoding lysogenic ... toxigenic Vibrio cholerae O1 with a common duckweed, Lemma minor, in ...

  8. Cholera Outbreak in Grande Comore: 1998-1999.

    Science.gov (United States)

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

    2016-01-01

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

  9. Survival of Vibrio cholerae O1 on fomites

    DEFF Research Database (Denmark)

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

    2016-01-01

    , 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......It is well established that the contamination sources of cholera causing bacteria, Vibrio cholerae, are water and food, but little is known about the transmission role of the fomites (surfaces that can carry pathogens) commonly used in households. In the absence of appropriate nutrients or growth...... conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass...

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

    African Journals Online (AJOL)

    2011-10-07

    Oct 7, 2011 ... co-ordination of relief aid, cultural stigmas regarding treatment of cholera and ..... doing research on the acceptance of interventions in response to ... national attention, commitment to help and resources at the expense of ...

  11. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

    Science.gov (United States)

    Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

    2013-01-01

    It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

  12. Internalization of cholera toxin by different endocytic mechanisms

    National Research Council Canada - National Science Library

    Torgersen, M L; Skretting, G; van Deurs, B; Sandvig, K

    2001-01-01

    The mechanism of cholera toxin (CT) internalization has been investigated using Caco-2 cells transfected with caveolin to induce formation of caveolae, HeLa cells with inducible synthesis of mutant dynamin (K44A...

  13. The role of immunity and seasonality in cholera epidemics.

    Science.gov (United States)

    Sanches, Rosângela P; Ferreira, Claudia P; Kraenkel, Roberto A

    2011-12-01

    This paper presents a mathematical model for cholera epidemics which comprises seasonality, loss of host immunity, and control mechanisms acting to reduce cholera transmission. A collection of data related to cholera disease allows us to show that outbreaks in endemic areas are subject to a resonant behavior, since the intrinsic oscillation period of the disease (∼1 year) is synchronized with the annual contact rate variation. Moreover, we argue that the short period of the host immunity may be associated to secondary peaks of incidence observed in some regions (a bimodal pattern). Finally, we explore some possible mechanisms of cholera control, and analyze their efficiency. We conclude that, besides mass vaccination--which may be impracticable--improvements in sanitation system and food/personal hygiene are the most effective ways to prevent an epidemic.

  14. [Laboratory diagnosis of cholera: analysis and prospects for improvement].

    Science.gov (United States)

    Telesmanich, N R; Lomov, Iu M

    2009-11-01

    Microbiological monitoring of the circulation of Vibro cholerae remains one of the key factors contributing to optimization of epidemiological surveillance in a specific area and the laboratory diagnosis of cholera is a basic applied tool for the detection and characterization of isolated cultures. The quality of etiological identification of the pathogen, the competent use of procedures, and the observance of a laboratory diagnosis scheme increases the likelihood of the cholera pathogen being detected in the samples taken from human beings and environmental objects, which allows to timely notify the disease and to prevent it. The current goals of investigations include the development of more accessible and rapid methods that would further find their place in the scheme for the laboratory diagnosis of cholera.

  15. Timely Response and Containment of 2016 Cholera Outbreak in ...

    African Journals Online (AJOL)

    cholera outbreak to guide outbreak preparedness and timely response ... place to investigate an outbreak of diarrhoeal disease of undetermined ... brought to Kapisha health post for treatment. Although ..... in place it has spread rapidly in Haiti.

  16. The cholera epidemic in South Africa, 1980 - 1987

    African Journals Online (AJOL)

    1991-05-04

    May 4, 1991 ... The dynamic spread of the seventh pandemic of cholera can conveniently be ... organism remain mobile and may spread the disease, shedding millions of vibrios ..... Mineral substitutes, electrolyte solutions and ion exchange.

  17. Cholera Outbreak in Grande Comore: 1998–1999

    Science.gov (United States)

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

    2016-01-01

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

  18. Genomic science in understanding cholera outbreaks and evolution of Vibrio cholerae as a human pathogen.

    Science.gov (United States)

    Robins, William P; Mekalanos, John J

    2014-01-01

    Modern genomic and bioinformatic approaches have been applied to interrogate the V. cholerae genome, the role of genomic elements in cholera disease, and the origin, relatedness, and dissemination of epidemic strains. A universal attribute of choleragenic strains includes a repertoire of pathogenicity islands and virulence genes, namely the CTXϕ prophage and Toxin Co-regulated Pilus (TCP) in addition to other virulent genetic elements including those referred to as Seventh Pandemic Islands. During the last decade, the advent of Next Generation Sequencing (NGS) has provided highly resolved and often complete genomic sequences of epidemic isolates in addition to both clinical and environmental strains isolated from geographically unconnected regions. Genomic comparisons of these strains, as was completed during and following the Haitian outbreak in 2010, reveals that most epidemic strains appear closely related, regardless of region of origin. Non-O1 clinical or environmental strains may also possess some virulence islands, but phylogenic analysis of the core genome suggests they are more diverse and distantly related than those isolated during epidemics. Like Haiti, genomic studies that examine both the Vibrio core and pan-genome in addition to Single Nucleotide Polymorphisms (SNPs) conclude that a number of epidemics are caused by strains that closely resemble those in Asia, and often appear to originate there and then spread globally. The accumulation of SNPs in the epidemic strains over time can then be applied to better understand the evolution of the V. cholerae genome as an etiological agent.

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

    Directory of Open Access Journals (Sweden)

    Fernanda S Freitas

    2002-06-01

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

  20. 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