Science.gov

Sample records for efficient glycopolypeptide-based cholera

  1. Cholera

    MedlinePlus

    ... cholerae. This same bacterium is also present in raw seafood, particularly shellfish. The best way to avoid ... contaminated with feces containing V. cholerae By eating raw shellfish contaminated with V. cholerae Who's At Risk ...

  2. Cholera

    PubMed Central

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

    2013-01-01

    Summary 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 diarrheal purging. Management of patients with cholera involves aggressive fluid replacement; effective therapy can decrease mortality from over 50% to less than 0.2%. Antibiotics decrease volume and duration of diarrhea by 50% and are recommended for patients with moderate to severe dehydration. Prevention of cholera depends on access to safe water and sanitation. Two oral cholera vaccines are available and the most effective use of these in integrated prevention programs is being actively evaluated. PMID:22748592

  3. Cholera.

    PubMed Central

    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. PMID:7704895

  4. Cholera

    MedlinePlus

    ... developed packets of salts that are mixed with clean water to help restore fluids. These are cheaper and ... cholera occur, efforts should be made to establish clean water, food, and sanitation. Vaccination is not very effective ...

  5. Cholera

    MedlinePlus

    ... universal access to safe drinking water and adequate sanitation, which is key in preventing both epidemic and endemic cholera. Actions targeting environmental conditions include: the development of piped water systems ...

  6. Cholera

    MedlinePlus

    ... usually found in water or food contaminated by feces (poop). Cholera is rare in the US. You may get it if you travel to parts of the world with inadequate water treatment and poor sanitation, and lack of sewage treatment. Outbreaks can also happen after disasters. The ...

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

    PubMed

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

    2016-04-19

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

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

    PubMed

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

    2016-06-01

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

  9. Implementation of a Symptomatic Approach Leads to Increased Efficiency of a Cholera Treatment Unit

    PubMed Central

    Ticona, Eduardo; Kirwan, Daniela E.; Soria, Jaime; Gilman, Robert H.

    2014-01-01

    Cholera is a disease of poverty that remains prevalent in resource-limited countries. The abrupt emergence of an epidemic frequently takes communities and health systems by surprise. Spread is rapid and initial mortality high: delays in organizing an appropriate response, lack of health worker training, and high patient numbers contribute to high rates of complications and deaths. PMID:25092822

  10. Cholera studies*

    PubMed Central

    Pollitzer, R.

    1957-01-01

    Discussing the symptomatology of cholera, the author deals first with the incubation period, the clinical types, choleraic diarrhoea, and cholerine; he then considers in detail the various stages of cholera gravis and the relapses and complications that may be met. This is followed by sections on diagnosis and differential diagnosis, and on prognosis and the various factors influencing it. The author's highly detailed review of the treatment of cholera which concludes this study is divided into three parts, dealing with attempts at specific therapy, with infusion treatment, and with adjuvant treatment. PMID:13426761

  11. Cholera outbreaks in Africa.

    PubMed

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

    2014-01-01

    an infectious dose of Vibrio cholerae and on the virulence of the implicated strain. Cholera transmission can then be amplified by several factors including contamination of human water- or food sources; climate and extreme weather events; political and economic crises; high population density combined with poor quality informal housing and poor hygiene practices; spread beyond a local community through human travel and animals, e.g., water birds. At an individual level, cholera risk may increase with decreasing immunity and hypochlorhydria, such as that induced by Helicobacter pylori infection, which is endemic in much of Africa, and may increase individual susceptibility and cholera incidence. Since contaminated water is the main vehicle for the spread of cholera, the obvious long-term solution to eradicate the disease is the provision of safe water to all African populations. This requires considerable human and financial resources and time. In the short and medium term, vaccination may help to prevent and control the spread of cholera outbreaks. Regardless of the intervention, further understanding of cholera biology and epidemiology is essential to identify populations and areas at increased risk and thus ensure the most efficient use of scarce resources for the prevention and control of cholera. PMID:24827501

  12. Cholera studies*

    PubMed Central

    Pollitzer, R.

    1957-01-01

    The first section of this study deals with areas where cholera is endemic and with the conditions normally favouring endemicity. Turning next to epidemics, the author discusses their origin and types, climatic influences on them, their periodicity and the possibility of forecasting them, the role played in them by different serological races of V. cholerae, and the causes of their decline. In a section on the factors governing the local spread of cholera, he considers contact and water-borne infection; the role of contaminated food and drink, of fomites, of flies, and of carriers; and the incidence according to sex, age, race, and occupation. The last part deals with factors governing the spread of cholera over longer distances, and includes discussion of the effect of movements of individuals and groups and of assemblies of the population on pilgrimages or at religious festivals. PMID:13472431

  13. Cholera studies*

    PubMed Central

    Swaroop, S.; Pollitzer, R.

    1955-01-01

    In this study, figures relating to cholera deaths occurring in individual countries, from 1900 to 1952, are recorded as well as the incidence of the disease from 1923 up to the present time. The mode of spread of cholera from its endemic home in India to outside countries is described in relation to favourable seasons, main routes followed by the infection, and the role played by large religious gatherings. The incidence of the disease in the various seaports infected within recent years is discussed. PMID:14364186

  14. Cholera studies*

    PubMed Central

    Pollitzer, R.

    1957-01-01

    After a general consideration of the loss of fluids and salts in evacuations from the gastro-intestinal tract, the author discusses in detail both the physical and the chemical changes in the blood of cholera patients. The author then deals exhaustively with the problems of circulatory and renal failure. PMID:13413649

  15. Cholera studies*

    PubMed Central

    Pollitzer, R.

    1956-01-01

    The first portion of this study describes in detail the different aspects of stool examinations, including the collection, preservation, and pooling of specimens, macroscopic and bacterioscopic examination, enrichment methods, and cultivation on a variety of solid media. The author also deals with the examination of vomits and of water. The performance and value of different identification tests (agglutination, haemolysis, and bacteriophage) and confirmatory tests are then considered. An annex is included on bacteriological procedures in the laboratory diagnosis of cholera. PMID:13356145

  16. Cholera studies*

    PubMed Central

    Pollitzer, R.

    1957-01-01

    In discussing prevention, the author deals first with the provision of permanently safe water, supplied from waterworks or wells, and with other improvements in environmental sanitation. Control of food and drinks, public health propaganda and education, and vaccination are also considered under this heading. The greater part of this study is devoted to suppressive measures, affecting the individual, the environment, and persons in the mass. Discussion of the isolation, detection and management of cholera patients, the management of contacts, and the management and treatment of carriers is followed by sections on, inter alia, disinfection, temporary improvements in water supplies, fly control, and personal prophylaxis. In dealing with mass prophylaxis, the author pays particular attention to vaccination. In the concluding sections he goes into the control of pilgrimages and local and international quarantine measures. PMID:13479774

  17. Cholera studies*†

    PubMed Central

    Pollitzer, R.; Burrows, W.

    1955-01-01

    Relevant information regarding the numerous problems encountered in cholera immunity is dealt with in great detail in this study. Toxin production, bacterial virulence, serological reactions, and the antigenic structure of V. cholerae are discussed. Natural, passive, and active cholera immunity receives special attention, the authors describing the various means of vaccination as well as the evaluation of the immunity induced. PMID:13240451

  18. Intestinal Colonization Dynamics of Vibrio cholerae

    PubMed Central

    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

  19. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    PubMed

    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. PMID:26845681

  20. Vibrio cholerae Biofilms and Cholera Pathogenesis

    PubMed Central

    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

  1. Cholera studies*†

    PubMed Central

    Pollitzer, R.

    1955-01-01

    In this study, the author describes in detail experimental cholera infection of mammals (infection by the oral route, intragastric inoculation, and intestinal, gall-bladder, and parenteral infection). The pathogenicity for lower animals is examined, and certain observations on insects are included. The second part of the study is devoted to the pathology of human cholera (morbid anatomy distribution of the causative organisms in the dead bodies of cholera victims, and pathogenesis). PMID:13284569

  2. Modeling cholera outbreaks

    PubMed Central

    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

  3. Cholera studies*†

    PubMed Central

    Pollitzer, R.

    1955-01-01

    The morphological characteristics, biochemical properties, and cultural characteristics of V. cholerae are described in great detail in this study. The author also discusses the resistance of the organism to temperature, humidity, sunlight, and various chemicals, as well as the viability of V. cholerae outside the body (in faeces, contaminated material, food, beverages, water, etc.). PMID:14379012

  4. Biochemistry of Vibrio cholerae virulence: purification of cholera enterotoxin by preparative disc electrophoresis.

    PubMed Central

    Lewis, A C; Richardson, S H; Sheridan, B

    1976-01-01

    Procedures for cholera enterotoxin purification previously developed in this labarotory were not applicable to large-scale purification, and these methods resulted in low yields of pure toxin. An efficient scheme has been developed whereby pure cholera enterotoxin can be obtained from 6 to 8 liters of culture supernatant fluid. This method consists of concentration by membrane ultrafiltration followed by gel filtration and cation-exchange chromatography. Pure cholera enterotoxin of high biological potency was obtained after a final step of preparative acrylamide gel electrophoresis. The degree of purity of the toxin-antigen as well as its biological activity were determined at various setps of purification. This alternate technique for purification is offered because of the widespread interest in cholera enterotoxin as a specific stimulator of adenyl cyclase. Images PMID:987751

  5. Cholera in the Americas.

    PubMed

    1991-01-01

    The cholera epidemic 1st hit South America in January 1991 in the coastal town of Chancay, Peru. In 2 weeks, it spread over 2000 km of the Pacific coast. By the end of the 1st month, it had already reached the mountains and tropical forests. By August 1991, cholera cases were reported in order of appearances in Ecuador, Colombia, Chile, Brazil, the US, Mexico, Guatemala, Bolivia, and El Salvador. Health authorities still do not know how it was introduced into South America. The case fatality rate has remained at a low of 1%, probably due to the prompt actions of health authorities in informing the public of the epidemic and what preventive cautions should be taken. This epidemic is part of the 7th pandemic which originated in Celebes, Indonesia in 1961. Cholera can spread relatively unchecked in Latin America because sewage in urban areas is not treated even though they do have sewage collection systems. The untreated wastewater enters rivers and the ocean. Consumption of raw seafood is not unusual and has been responsible for cholera infection in some cases. In fact, many countries placed import restrictions on marine products from Peru following the outbreak at a loss of $US10-$US40 million. Municipal sewage treatment facilities, especially stabilization ponds, would prevent the spread of cholera and other pathogens. In rural areas, pit latrines located away from wells can effectively dispose of human wastes. Most water supplies in Latin America are not disinfected. Disinfection drinking water with adequate levels of chlorine would effectively destroy V. cholera. If this is not possible, boiling the water for 2-3 minutes would destroy the pathogen. Any cases of cholera must be reported to PAHO. PAHO has responded to the outbreak by forming a Cholera Task Force and arranged transport of oral rehydration salts, intravenous fluids, antibiotics, and other essential medical supplies. PMID:1742573

  6. NAD metabolism in Vibrio cholerae.

    PubMed Central

    Foster, J W; Brestel, C

    1982-01-01

    Extracts of Vibrio cholerae were assayed for various enzymatic activities associated with pyridine nucleotide cycle metabolism. The activities measured include NAD glycohydrolase, nicotinamide deamidase, nicotinamide mononucleotide deamidase, and nicotinic acid phosphoribosyltransferase. The results obtained demonstrate the existence in V. cholerae of the five-membered pyridine nucleotide cycle and the potential for a four-membered pyridine nucleotide cycle. The data presented also suggest that most of the NAD glycohydrolase in V. cholerae extracts is not directly related to cholera toxin. PMID:6119307

  7. The global burden of cholera

    PubMed Central

    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

  8. Cholera studies*†

    PubMed Central

    Pollitzer, R.

    1954-01-01

    In this, the first of a series of cholera studies, the history of the disease from its earliest recorded appearance up to 1923 is outlined, and its geographical distribution described. The origins and main routes of spread of the six great pandemics are indicated; possible causes of the variations in mortality which accompanied them are discussed. PMID:13160764

  9. A long-term carrier of cholera: Cholera Dolores

    PubMed Central

    Azurin, J. C.; Kobari, Kazumine; Barua, D.; Alvero, M.; Gomez, C. Z.; Dizon, J. J.; Nakano, Ei-Ichi; Suplido, R.; Ledesma, L.

    1967-01-01

    The first known long-term carrier of cholera, found in the Philippines, is described. The carrier, Dolores M., who had suffered from El Tor cholera in August 1962, continued intermittently to excrete vibrios of the same characteristics as the original isolates until the date of reporting (1966). Duodenal intubation proved that the vibrios are lodged in her biliary tract. Her serum antibody titre continued to remain high in the absence of vaccination against cholera. PMID:5300877

  10. Antibiotic therapy of cholera*

    PubMed Central

    Lindenbaum, John; Greenough, William B.; Islam, M. R.

    1967-01-01

    Recent clinical trials having established the value of tetracycline as an adjunct to fluid and electrolyte replacement in cholera treatment, a controlled trial of antibiotic therapy was conducted in Dacca on 318 adults hospitalized for cholera. The effects of 4 antibiotics orally administered in varying dosage schedules were studied. Cholera therapy with tetracycline or chloramphenicol caused a highly significant reduction in the duration of diarrhoea and of positive culture, in stool volume, and in intravenous fluid requirement as compared with the results in controls who received intravenous fluid therapy only. Streptomycin was also effective, but to a lesser degree; paromomycin was of little value. The severity of dehydration on admission was significantly related to subsequent duration of diarrhoea regardless of whether antibiotics were given. Increasing age was associated with more prolonged purging in patients receiving antibiotics. Increasing the dose of tetracycline to 2 to 3 times that usually administered, or prolonging treatment from 2 to 4 days, did not enhance the therapeutic results. The effect of tetracycline was apparent within a few hours of administration. Bacteriological relapses were seen after discontinuation of therapy in all treatment groups, but were not due to the development of resistant bacteria. PMID:4865453

  11. Vulnerability to coastal cholera ecology.

    PubMed

    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. PMID:12927470

  12. Environmental Monitoring of Endemic Cholera

    NASA Astrophysics Data System (ADS)

    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.

  13. Environmental Factors Influencing Epidemic Cholera

    PubMed Central

    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

  14. Epidemic cholera spreads like wildfire

    PubMed Central

    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. PMID:24424273

  15. Spatially explicit modelling of cholera epidemics

    NASA Astrophysics Data System (ADS)

    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.

  16. Cholera and the Scientific Method.

    ERIC Educational Resources Information Center

    Cronin, Jim

    1993-01-01

    Describes an approach to teaching the scientific method where an outbreak of cholera within the school is simulated. Students act like epidemiologists in an attempt to track down the source of the contamination. (PR)

  17. Human Mobility Patterns and Cholera Epidemics: a Spatially Explicit Modeling Approach

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Cholera is an acute enteric disease caused by the ingestion of water or food contaminated by the bacterium Vibrio cholerae. Although most infected individuals do not develop severe symptoms, their stool may contain huge quantities of V.~cholerae cells. Therefore, while traveling or commuting, asymptomatic carriers can be responsible for the long-range dissemination of the disease. As a consequence, human mobility is an alternative and efficient driver for the spread of cholera, whose primary propagation pathway is hydrological transport through river networks. We present a multi-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of V.~cholerae due to human movement. In particular, building on top of state-of-the-art spatially explicit models for cholera spread through surface waters, we describe human movement and its effects on the propagation of the disease by means of a gravity-model approach borrowed from transportation theory. Gravity-like contact processes have been widely used in epidemiology, because they can satisfactorily depict human movement when data on actual mobility patterns are not available. We test our model against epidemiological data recorded during the cholera outbreak occurred in the KwaZulu-Natal province of South Africa during years 2000--2001. We show that human mobility does actually play an important role in the formation of the spatiotemporal patterns of cholera epidemics. In particular, long-range human movement may determine inter-catchment dissemination of V.~cholerae cells, thus in turn explaining the emergence of epidemic patterns that cannot be produced by hydrological transport alone. We also show that particular attention has to be devoted to study how heterogeneously distributed drinking water supplies and sanitation conditions may affect cholera transmission.

  18. Cholera Vaccination in Urban Haiti

    PubMed Central

    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

  19. Epidemiology of Cholera in the Philippines

    PubMed Central

    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

  20. Antimicrobial drugs for treating cholera

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Cholera: pathophysiology and emerging therapeutic targets.

    PubMed

    Muanprasat, Chatchai; Chatsudthipong, Varanuj

    2013-05-01

    Cholera is a diarrheal disease that remains an important global health problem with several hundreds of thousands of reported cases each year. This disease is caused by intestinal infection with Vibrio cholerae, which is a highly motile gram-negative bacterium with a single-sheathed flagellum. In the course of cholera pathogenesis, V. cholerae expresses a transcriptional activator ToxT, which subsequently transactivates expressions of two crucial virulence factors: toxin-coregulated pilus and cholera toxin (CT). These factors are responsible for intestinal colonization of V. cholerae and induction of fluid secretion, respectively. In intestinal epithelial cells, CT binds to GM1 ganglioside receptors on the apical membrane and undergoes retrograde vesicular trafficking to endoplasmic reticulum, where it exploits endoplasmic reticulum-associated protein degradation systems to release a catalytic A1 subunit of CT (CT A1) into cytoplasm. CT A1, in turn, catalyzes ADP ribosylation of α subunits of stimulatory G proteins, leading to a persistent activation of adenylate cyclase and an elevation of intracellular cAMP. Increased intracellular cAMP in human intestinal epithelial cells accounts for pathogenesis of profuse diarrhea and severe fluid loss in cholera. This review provides an overview of the pathophysiology of cholera diarrhea and discusses emerging drug targets for cholera, which include V. cholerae virulence factors, V. cholerae motility, CT binding to GM1 receptor, CT internalization and intoxication, as well as cAMP metabolism and transport proteins involved in cAMP-activated Cl(-) secretion. Future directions and perspectives of research on drug discovery and development for cholera are discussed. PMID:23651092

  3. Bacteriocin Typing of Vibrio cholerae

    PubMed Central

    Chakrabarty, A. N.; Adhya, Sati; Basu, Jayantisri; Dastidar, Sujata G.

    1970-01-01

    Bacteriocins of Vibrio cholerae have been demonstrated against enterobacterial and vibrio indicator organisms by conventional techniques. Abundant bacteriocin production took place on casein hydrolysate-yeast extract, tryptic soy, digest broth, proteose-peptone, and neopeptone agars. Essential factors were a citrate-phosphate buffer concentration of 0.5 to 0.7%, at pH 7.5 to 7.6, and cold shock. Thermal treatment of indicator organisms at 45 C for 12 min increased the percentage of typable strains. The bacteriocins of V. cholerae appeared to be powerful diffusible bactericidal agents. By using 8 indicator strains, 11 bacteriocin types have been recognized among 425 strains, of which 87% are typable at present. Images PMID:16557731

  4. Evaluation of enteric-coated tablets as a whole cell inactivated vaccine candidate against Vibrio cholerae.

    PubMed

    Fernández, Sonsire; Año, Gemma; Castaño, Jorge; Pino, Yadira; Uribarri, Evangelina; Riverón, Luis A; Cedré, Bárbara; Valmaseda, Tania; Falero, Gustavo; Pérez, José L; Infante, Juan F; García, Luis G; Solís, Rosa L; Sierra, Gustavo; Talavera, Arturo

    2013-01-01

    A vaccine candidate against cholera was developed in the form of oral tablets to avoid difficulties during application exhibited by current whole cell inactivated cholera vaccines. In this study, enteric-coated tablets were used to improve the protection of the active compound from gastric acidity. Tablets containing heat-killed whole cells of Vibrio cholerae strain C7258 as the active pharmaceutical compound was enteric-coated with the polymer Kollicoat(®) MAE-100P, which protected them efficiently from acidity when a disintegration test was carried out. Enzyme-linked immunosorbent assay (ELISA) anti-lipopolysaccharide (LPS) inhibition test and Western blot assay revealed the presence of V. cholerae antigens as LPS, mannose-sensitive haemagglutinin (MSHA) and outer membrane protein U (Omp U) in enteric-coated tablets. Immunogenicity studies (ELISA and vibriocidal test) carried out by intraduodenal administration in rabbits showed that the coating process of tablets did not affect the immunogenicity of V. cholerae-inactivated cells. In addition, no differences were observed in the immune response elicited by enteric-coated or uncoated tablets, particularly because the animal model and immunization route used did not allow discriminating between acid resistances of both tablets formulations in vivo. Clinical studies with volunteers will be required to elucidate this aspect, but the results suggest the possibility of using enteric-coated tablets as a final pharmaceutical product for a cholera vaccine. PMID:23492079

  5. VGJphi integration and excision mechanisms contribute to the genetic diversity of Vibrio cholerae epidemic strains.

    PubMed

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

    2011-02-01

    Most strains of Vibrio cholerae are not pathogenic or cause only local outbreaks of gastroenteritis. Acquisition of the capacity to produce the cholera toxin results from a lysogenic conversion event due to a filamentous bacteriophage, CTX. Two V. cholerae tyrosine recombinases that normally serve to resolve chromosome dimers, XerC and XerD, promote CTX integration by directly recombining the ssDNA genome of the phage with the dimer resolution site of either or both V. cholerae chromosomes. This smart mechanism renders the process irreversible. Many other filamentous vibriophages seem to attach to chromosome dimer resolution sites and participate in the rapid and continuous evolution of toxigenic V. cholerae strains. We analyzed the molecular mechanism of integration of VGJ, a representative of the largest family of these phages. We found that XerC and XerD promote the integration of VGJ into a specific chromosome dimer resolution site, and that the dsDNA replicative form of the phage is recombined. We show that XerC and XerD can promote excision of the integrated prophage, and that this participates in the production of new extrachromosomal copies of the phage genome. We further show how hybrid molecules harboring the concatenated genomes of CTX and VGJ can be produced efficiently. Finally, we discuss how the integration and excision mechanisms of VGJ can explain the origin of recent epidemic V. cholerae strains. PMID:21262799

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

    PubMed

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

    2014-06-01

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

  7. 9 CFR 311.3 - Hog cholera.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of hog... kidneys and lymph nodes of carcasses of hogs which appeared normal on ante-mortem inspection, further..., characteristic lesions of hog cholera are found in some organ or tissue in addition to those in the kidneys or...

  8. 9 CFR 311.3 - Hog cholera.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of hog... kidneys and lymph nodes of carcasses of hogs which appeared normal on ante-mortem inspection, further..., characteristic lesions of hog cholera are found in some organ or tissue in addition to those in the kidneys or...

  9. 9 CFR 311.3 - Hog cholera.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of hog... kidneys and lymph nodes of carcasses of hogs which appeared normal on ante-mortem inspection, further..., characteristic lesions of hog cholera are found in some organ or tissue in addition to those in the kidneys or...

  10. 9 CFR 311.3 - Hog cholera.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of hog... kidneys and lymph nodes of carcasses of hogs which appeared normal on ante-mortem inspection, further..., characteristic lesions of hog cholera are found in some organ or tissue in addition to those in the kidneys or...

  11. 9 CFR 311.3 - Hog cholera.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... kidneys and the lymph nodes which resemble lesions of hog cholera, they shall be regarded as those of hog... kidneys and lymph nodes of carcasses of hogs which appeared normal on ante-mortem inspection, further..., characteristic lesions of hog cholera are found in some organ or tissue in addition to those in the kidneys or...

  12. Can chatter between microbes prevent cholera?

    PubMed

    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. PMID:25468792

  13. Genomic diversity of 2010 Haitian cholera outbreak strains.

    PubMed

    Hasan, Nur A; Choi, Seon Young; Eppinger, Mark; Clark, Philip W; Chen, Arlene; Alam, Munirul; Haley, Bradd J; Taviani, Elisa; Hine, Erin; Su, Qi; Tallon, Luke J; Prosper, Joseph B; Furth, Keziah; Hoq, M M; Li, Huai; Fraser-Liggett, Claire M; Cravioto, Alejandro; Huq, Anwar; Ravel, Jacques; Cebula, Thomas A; Colwell, Rita R

    2012-07-17

    The millions of deaths from cholera during the past 200 y, coupled with the morbidity and mortality of cholera in Haiti since October 2010, are grim reminders that Vibrio cholerae, the etiologic agent of cholera, remains a scourge. We report the isolation of both V. cholerae O1 and non-O1/O139 early in the Haiti cholera epidemic from samples collected from victims in 18 towns across eight Arrondissements of Haiti. The results showed two distinct populations of V. cholerae coexisted in Haiti early in the epidemic. As non-O1/O139 V. cholerae was the sole pathogen isolated from 21% of the clinical specimens, its role in this epidemic, either alone or in concert with V. cholerae O1, cannot be dismissed. A genomic approach was used to examine similarities and differences among the Haitian V. cholerae O1 and V. cholerae non-O1/O139 strains. A total of 47 V. cholerae O1 and 29 V. cholerae non-O1/O139 isolates from patients and the environment were sequenced. Comparative genome analyses of the 76 genomes and eight reference strains of V. cholerae isolated in concurrent epidemics outside Haiti and 27 V. cholerae genomes available in the public database demonstrated substantial diversity of V. cholerae and ongoing flux within its genome. PMID:22711841

  14. Toxigenic Vibrio cholerae O1 in Water and Seafood, Haiti

    PubMed Central

    Cohen, Nicole; Kahler, Amy M.; Jones, Jessica L.; Bopp, Cheryl A.; Marano, Nina; Tarr, Cheryl L.; Garrett, Nancy M.; Boncy, Jacques; Henry, Ariel; Gómez, Gerardo A.; Wellman, Michael; Curtis, Maurice; Freeman, Molly M.; Turnsek, Maryann; Benner, Ronald A.; Dahourou, Georges; Espey, David; DePaola, Angelo; Tappero, Jordan W.; Handzel, Tom; Tauxe, Robert V.

    2011-01-01

    During the 2010 cholera outbreak in Haiti, water and seafood samples were collected to detect Vibrio cholerae. The outbreak strain of toxigenic V. cholerae O1 serotype Ogawa was isolated from freshwater and seafood samples. The cholera toxin gene was detected in harbor water samples. PMID:22099121

  15. Induction of melanin biosynthesis in Vibrio cholerae.

    PubMed Central

    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 in the culture supernatant decreased significantly in response to stressful culture conditions, no correlation between the physiological conditions that induced melanogenesis and expression of OmpU or cholera toxin was detected. Since conditions that induce melanin production in V. cholerae occur in both the aquatic environment and the human host, it is possible that melanogenesis has a specific function with respect to the survival of the bacterium in these habitats. PMID:1444398

  16. Nepalese origin of cholera epidemic in Haiti.

    PubMed

    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. PMID:22510219

  17. Blood Group O-Dependent Cellular Responses to Cholera Toxin: Parallel Clinical and Epidemiological Links to Severe Cholera.

    PubMed

    Kuhlmann, F Matthew; Santhanam, Srikanth; Kumar, Pardeep; Luo, Qingwei; Ciorba, Matthew A; Fleckenstein, James M

    2016-08-01

    Because O blood group has been associated with more severe cholera infections, it has been hypothesized that cholera toxin (CT) may bind non-O blood group antigens of the intestinal mucosae, thereby preventing efficient interaction with target GM1 gangliosides required for uptake of the toxin and activation of cyclic adenosine monophosphate (cAMP) signaling in target epithelia. Herein, we show that after exposure to CT, human enteroids expressing O blood group exhibited marked increase in cAMP relative to cells derived from blood group A individuals. Likewise, using CRISPR/Cas9 engineering, a functional group O line (HT-29-A(-/-)) was generated from a parent group A HT-29 line. CT stimulated robust cAMP responses in HT-29-A(-/-) cells relative to HT-29 cells. These findings provide a direct molecular link between blood group O expression and differential cellular responses to CT, recapitulating clinical and epidemiologic observations. PMID:27162272

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

    PubMed Central

    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 associated with diarrhea. PMID:24303485

  19. Antimicrobials & cholera: are we stranded?

    PubMed

    Ghosh, Amit; Ramamurthy, T

    2011-02-01

    Antimicrobial resistance poses a major threat in the treatment of infectious diseases. Though significant progress in the management of diarrhoeal diseases has been achieved by improved hygiene, development of new antimicrobials and vaccines, the burden remains the same, especially in children below 5 yr of age. In the case of cholera, though oral rehydration treatment is the mainstay, antimicrobial therapy is mandatory at times to reduce the volume of stool and shorten the duration of the disease. Though for many pathogens, antimicrobial resistance emerged soon after the introduction of antibiotics, Vibrio cholerae remained sensitive to most of the antibiotics for quite a long period. However, the scenario changed over the years and today, V. cholerae strains isolated world over are resistant to multiple antibiotics. A myriad number of mechanisms underlie this phenomenon. These include production of extended-spectrum beta-lactamases, enhanced multi-drug efflux pump activity, plasmid-mediated quinolone and fluoroquinolone resistance, and chromosomal mutations. Horizontal transfer of resistance determinants with mobile genetic elements like integrons and the integrating conjugative elements (ICEs), SXTs help in the dissemination of drug resistance. Though all strains isolated are not resistant to all antibiotics and we are not as yet "stranded", expanding spectrum of drug resistance is a definite cause for concern. Pipelines of discovery of new antibiotics are drying up as major pharmaceutical companies are losing interest in investing money in this endeavour, mainly due to the short shelf-life of the antibiotics and also due to the fast emergence of drug resistance. To address this issue, attempts are now being made to discover drugs which are pathogen specific and target their "virulence mechanisms". It is expected that development of resistance against such antibiotics would take much longer. This review briefly focuses on all these issues. PMID:21415499

  20. In silico prediction of drug targets in Vibrio cholerae.

    PubMed

    Katara, Pramod; Grover, Atul; Kuntal, Himani; Sharma, Vinay

    2011-10-01

    Identification of potential drug targets is the first step in the process of modern drug discovery, subjected to their validation and drug development. Whole genome sequences of a number of organisms allow prediction of potential drug targets using sequence comparison approaches. Here, we present a subtractive approach exploiting the knowledge of global gene expression along with sequence comparisons to predict the potential drug targets more efficiently. Based on the knowledge of 155 known virulence and their coexpressed genes mined from microarray database in the public domain, 357 coexpressed probable virulence genes for Vibrio cholerae were predicted. Based on screening of Database of Essential Genes using blastn, a total of 102 genes out of these 357 were enlisted as vitally essential genes, and hence good putative drug targets. As the effective drug target is a protein which is only present in the pathogen, similarity search of these 102 essential genes against human genome sequence led to subtraction of 66 genes, thus leaving behind a subset of 36 genes whose products have been called as potential drug targets. The gene ontology analysis using Blast2GO of these 36 genes revealed their roles in important metabolic pathways of V. cholerae or on the surface of the pathogen. Thus, we propose that the products of these genes be evaluated as target sites of drugs against V. cholerae in future investigations. PMID:21174131

  1. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3O4)) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe3O4 and CA-Fe3O4/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, CA-Fe3O4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe3O4) and 189.51 nm (CA-Fe3O4) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2O3/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL-1 with a low detection limit of 0.32 ng mL-1, sensitivity 0.03 Ω/ng ml-1 cm-2, and reproducibility more than 11 times.

  2. [Cholera in a district of Peru].

    PubMed

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

    1996-01-01

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

  3. Cholera Epidemiology in Nigeria: an overview

    PubMed Central

    Adagbada, Ajoke Olutola; Adesida, Solayide Abosede; Nwaokorie, Francisca Obiageri; Niemogha, Mary-Theresa; Coker, Akitoye Olusegun

    2012-01-01

    Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium, Vibrio cholera. Choleragenic V. cholera O1 and O139 are the only causative agents of the disease. The two most distinguishing epidemiologic features of the disease are its tendency to appear in explosive outbreaks and its predisposition to causing pandemics that may progressively affect many countries and spread into continents. Despite efforts to control cholera, the disease continues to occur as a major public health problem in many developing countries. Numerous studies over more than a century have made advances in the understanding of the disease and ways of treating patients, but the mechanism of emergence of new epidemic strains, and the ecosystem supporting regular epidemics, remain challenging to epidemiologists. In Nigeria, since the first appearance of epidemic cholera in 1972, intermittent outbreaks have been occurring. The later part of 2010 was marked with severe outbreak which started from the northern part of Nigeria, spreading to the other parts and involving approximately 3,000 cases and 781 deaths. Sporadic cases have also been reported. Although epidemiologic surveillance constitutes an important component of the public health response, publicly available surveillance data from Nigeria have been relatively limited to date. Based on existing relevant scientific literature on features of cholera, this paper presents a synopsis of cholera epidemiology emphasising the situation in Nigeria. PMID:22937199

  4. The deadliest wake-up call. Cholera.

    PubMed

    Dajer, T

    1992-01-01

    It is clear that cholera has caused an uproar in Latin America, but the meaning of the epidemic is not so certain. In January 1991, cases of cholera began to spring up along the coast north of Lima. A year later, 1/2 million people in the continent had fallen ill from the disease and over 4000 had died from it. There is not effective antibiotic of vaccine against it. Sanitation is the only "cure" for cholera, a disease which can dehydrate and kill an otherwise strong and healthy person in 6 hours. There are 4 ways of looking at the significance of the epidemic: 1) Who cares? 4000 deaths -- less and 1% of all cholera cases -- is a minuscule figure. Last year in Africa, over 11,000 cholera deaths went unnoticed by the press. 2) The Lost 80s. Economically disastrous for Latin America, the 1980s saw billions of dollars being siphoned out of the continent by multinational banks, money that should have gone into public works and water systems. 3) Just Nature Doing Her Thing. The outbreak of cholera in Latin America is simply the most recent stop of a worldwide cholera epidemic which began in Indonesia in 1961. And 4) Kids Don't Count. In 1991, some 200,000 mostly poor Latin American children died of common diarrheal diseases. Only when bad water began affecting adults was rehydration therapy emphasized. None of these 4 explanations, however, fully explains the commotions surrounding the cholera outbreak. Cholera is one of those diseases that can brand a country as backwards. At bottom, the epidemic represents an embarrassment to the ruling classes of the Latin America. PMID:12159273

  5. A De in the life of cholera.

    PubMed

    Hall, Robert H

    2011-02-01

    The 50-year commemoration of S.N. De's seminal 1959 publication in Nature provides an opportunity to reflect on scientific discovery, recognition, and public health. De's paper marked the first major conceptual advance in cholera research since 1884, when Robert Koch definitively identified Der Kommabazillus as the aetiological agent of cholera. Unfortunately, Koch reported that systemic toxinosis and multi-organ failure led to severe dehydrating diarrhoea, thereby mistaking cause for effect. As a consequence, while work on other microbial pathogens advanced into the development of vaccines and therapeutics, cholera research languished as scientists injected animals parenterally in decades of futile effort to develop an animal model of diarrhoea. This fundamental misconception in cholera pathogenesis was swept away when S.N. De used ligated loops of rabbit ileum to demonstrate lumenal fluid accumulation in the presence of Vibrio cholerae culture filtrates. After some delay, De's observation of a diarrhoeagenic exotoxin became the founding principle of modern cholera research, vaccination, and treatment; and a burst of discovery saw V. cholerae transformed into the enteric pathogen best understood at the molecular level. The scientific basis for orally administering vaccines to induce mucosal immunity was established, and the success of oral rehydration, what has been described as one of the 20 th century's most important medical advances, was explained. Nobel laureate Joshua Lederberg wrote of De's iconoclastic creativity, experimental skill, and observational mastery, and many other leaders in the field concurred. De was nominated for the Nobel Prize in Physiology or Medicine more than once. But despite the passage of half a century from De's work, cholera remains a frustrating problem: we are clearly missing something. In reviewing the scientific and programmatic impact of S.N. De on cholera, it is clear that a defining victory against the disease is achievable

  6. Mesenteric Panniculitis Associated With Vibrio cholerae Infection

    PubMed Central

    Roginsky, Grigory; Mazulis, Andrew; Ecanow, Jacob S.

    2015-01-01

    We report the first case of acute Vibrio cholerae infection with computed tomography (CT) changes consistent with mesenteric panniculitis (MP). A 78-year-old Indian man returned from overseas travel with progressively severe nausea, vomiting, abdominal pain, and watery diarrhea. His stool tested positive twice for Vibrio cholerae. CT revealed prominent lymph nodes and a hazy mesentery consistent with MP. Antibiotic treatment resulted in complete resolution of MP on follow-up CT 8 months later. In the setting of Vibrio cholerae infection, the CT finding of MP appears to be the result of a immunologically mediated reactive inflammatory disorder of the mesentery. PMID:26504876

  7. A case of cholera in Kingston, Ont.

    PubMed Central

    Bourdages, R.; Beck, I. T.

    1976-01-01

    A case of cholera occurred in Kingston, Ont. in 1974 in a traveller from South Africa. Treatment, based on an understanding of the pathophysiology of cholera diarrhea and the mechanism of action of the Vibrio cholerae enterotoxin on gastrointestinal fluid loss, consisted of correcting the severe loss of fluid and electrolytes and the metabolic acidosis, as soon as the patient could tolerate taking fluids orally, further fluid replacement consisted increasingly of oral administration of glucose and saline. Tetracycline therapy was given only to shorten the duration of the acute illness. PMID:953912

  8. Influence of human behavior on cholera dynamics

    PubMed Central

    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 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). PMID:26119824

  9. EFFECT OF AGGREGATION ON VIBRIO CHOLERA INACTIVATION

    EPA Science Inventory

    Extensive research has shown that microorganisms exhibit increased resistance due to clumping, aggregation, particle association or modification of antecedent growth conditions. uring the course of investigating a major waterborne V. Cholerae outbreak in Peru, U.S. EPA investigat...

  10. Are wetlands the reservoir for avian cholera?

    USGS Publications Warehouse

    Samuel, M.D.; Shadduck, D.J.; Goldberg, D.R.

    2004-01-01

    Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995a??98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

  11. Pursuing Justice in Haiti's Cholera Epidemic.

    PubMed

    Weinmeyer, Richard

    2016-01-01

    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. PMID:27437822

  12. Genome Sequences of Clinical Vibrio cholerae Isolates from an Oyster-Borne Cholera Outbreak in Florida

    PubMed Central

    Haley, Bradd J.; Choi, Seon Young; Hasan, Nur A.; Abdullah, Abdul Shakur H.; Cebula, Thomas A.; Huq, Anwar

    2013-01-01

    Between November 2010 and April 2011, 11 cases of cholera were identified and associated with the consumption of raw oysters harvested from Apalachicola Bay, Florida. The etiological agent was the ctxAB-positive Vibrio cholerae serogroup O75. The genome sequences of the isolates provide useful information and are deposited in the public genome databases. PMID:24265497

  13. Genome Sequences of Clinical Vibrio cholerae Isolates from an Oyster-Borne Cholera Outbreak in Florida.

    PubMed

    Haley, Bradd J; Choi, Seon Young; Hasan, Nur A; Abdullah, Abdul Shakur H; Cebula, Thomas A; Huq, Anwar; Colwell, Rita R

    2013-01-01

    Between November 2010 and April 2011, 11 cases of cholera were identified and associated with the consumption of raw oysters harvested from Apalachicola Bay, Florida. The etiological agent was the ctxAB-positive Vibrio cholerae serogroup O75. The genome sequences of the isolates provide useful information and are deposited in the public genome databases. PMID:24265497

  14. Cholera

    MedlinePlus

    ... While You Travel Dengue Fever Malaria Typhoid Fever Ebola First Aid: Diarrhea Stool Test: Bacteria Culture Do ... Food Poisoning Why Is Hand Washing So Important? Ebola Why Do I Need to Wash My Hands? ...

  15. Cholera

    MedlinePlus

    ... Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions Cleft & Craniofacial Developmental Disabilities Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ...

  16. Cholera

    MedlinePlus

    ... with suspected enteric infection. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ... with diarrhea and malabsorption. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: ...

  17. Cholera risk factors, Papua New Guinea, 2010

    PubMed Central

    2012-01-01

    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. PMID:23126504

  18. Avian cholera in Nebraska's Rainwater Basin

    USGS Publications Warehouse

    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.

  19. Cholera dynamics and El Niño-Southern Oscillation.

    PubMed

    Pascual, M; Rodó, X; Ellner, S P; Colwell, R; Bouma, M J

    2000-09-01

    Analysis of a monthly 18-year cholera time series from Bangladesh shows that the temporal variability of cholera exhibits an interannual component at the dominant frequency of El Niño-Southern Oscillation (ENSO). Results from nonlinear time series analysis support a role for both ENSO and previous disease levels in the dynamics of cholera. Cholera patterns are linked to the previously described changes in the atmospheric circulation of south Asia and, consistent with these changes, to regional temperature anomalies. PMID:10976073

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

    PubMed Central

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

    2016-01-01

    ABSTRACT An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX−) V. cholerae El Tor dominated toxigenic (CTX+) strains (2001 to 2003), but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX− V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+ V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity. PMID:26980836

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

    PubMed Central

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

    2016-01-01

    Background In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1–15 years in selected communities in Choiseul and Western Provinces. Methodology and Principal Findings We conducted a post-vaccination campaign, household-level survey about 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. Conclusions 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. PMID:27548678

  2. Monoclonal antibodies against Vibrio cholerae lipopolysaccharide.

    PubMed Central

    Gustafsson, B; Rosén, A; Holme, T

    1982-01-01

    A cell line producing monoclonal antibodies directed against the core region of Vibrio cholerae lipopolysaccharide has been established. These antibodies were inhibited by lipopolysaccharide preparations of both O-group 1 vibrios and some non-O-group 1 vibrios as detected in enzyme-linked immunosorbent assay-inhibition experiments. Coagglutination experiments with monoclonal and polyclonal antibodies adsorbed to protein A-carrying staphylococci were performed. All V. cholerae strains tested, regardless of serotype, were agglutinated when mixed with staphylococci coated with the monoclonal antibodies, whereas staphylococci coated with group-specific (O1) polyclonal antibodies only agglutinated with O-group 1 vibrios. Images PMID:6183214

  3. Spreading of Cholera through Surface Water

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    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. PMID:27192187

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

    PubMed Central

    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

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

    PubMed

    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 population and in a population with endemic cholera. In the population at risk for endemic cholera, mass vaccination with BS-WC vaccine is the least cost-effective intervention compared with the provision of safe drinking-water and sanitation or with treatment of the disease. In a refugee population at risk for epidemic disease, the cost-effectiveness of vaccination is similar to that of providing safe drinking-water and sanitation alone, though less cost-effective than treatment alone or treatment combined with the provision of water and sanitation. The implications of these data for public health decision-makers and programme managers are discussed. There is a need for better information on the feasibility and costs of administering oral cholera vaccine in refugee populations and populations with endemic cholera. PMID:9803585

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

    PubMed

    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. PMID:26718467

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

    PubMed

    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. PMID:23945156

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

    NASA Astrophysics Data System (ADS)

    Abdussalam, Auwal; Thornes, John; Leckebusch, Gregor

    2015-04-01

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

  12. [A boy with cholera from India].

    PubMed

    van Furth, A M; Croughs, R D; Terpstra, L; Vandenbroucke-Grauls, C M J E; van Well, G T H

    2006-01-28

    A 7-year-old Indian boy travelling from India to the United Kingdom was brought to the Emergency Clinic of Airport Medical Services at Schiphol airport in Amsterdam, the Netherlands. He had had watery diarrhoea in the aircraft and had lost consciousness. In view of the strong indications for cholera and the rice water-like diarrhoea, he was admitted to the paediatric ward of the VU Medical Centre where intravenous rehydration was carried out. He recovered within three days. A large number of comma-shaped, motile, Gram-negative rods were found in the faeces. After two days, the faeces culture revealed Vibrio cholerae O1 El Tor, serotype Inaba. On the day of the flight, the patient had drunk a litre of water from a bottle that later turned out to have been from the New Delhi water supply. Cholera is rare as an import disease in the Netherlands. Due to the severe dehydration, the infection can run a serious course and even be fatal. The infection is not transmitted from person to person. Therefore, no special measures are needed when a patient with cholera is admitted to hospital. PMID:16471238

  13. Surface-attachment sequence in Vibrio Cholerae

    NASA Astrophysics Data System (ADS)

    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).

  14. EFFECT OF AGGREGATION ON VIBRIO CHOLERAE INACTIVATION

    EPA Science Inventory

    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...

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

    PubMed Central

    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. PMID:27118300

  16. Tracking Cholera in Coastal Regions using Satellite Observations

    PubMed Central

    Jutla, Antarpreet S; Akanda, Ali S; Islam, Shafiqul

    2010-01-01

    Cholera remains a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and then spread inland through secondary means. Cholera bacteria show strong association with plankton abundance in coastal ecosystems. This review study investigates relationship(s) between cholera incidence and coastal processes and explores utility of using remote sensing data to track coastal plankton blooms, using chlorophyll as a surrogate variable for plankton abundance, and subsequent cholera outbreaks. Most studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks. Accurate identification and mechanistic understanding of large scale climatic, geophysical and oceanic processes governing cholera-chlorophyll relationship is important for developing cholera prediction models. Development of a holistic understanding of these processes requires long and reliable chlorophyll dataset(s), which are beginning to be available through satellites. We have presented a schematic pathway and a modeling framework that relate cholera with various hydroclimatic and oceanic variables for understanding disease dynamics using latest advances in remote sensing. Satellite data, with its unprecedented spatial and temporal coverage, have potentials to monitor coastal processes and track cholera outbreaks in endemic regions. PMID:21072249

  17. Cholera: Environmental Reservoirs and Impact on Disease Transmission

    PubMed Central

    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

  18. Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

    SciTech Connect

    Brettin, Thomas S; Bruce, David C; Challacombe, Jean F; Detter, John C; Han, Cliff S; Munik, A C; Chertkov, Olga; Meincke, Linda; Saunders, Elizabeth; Choi, Seon Y; Haley, Bradd J; Taviani, Elisa; Jeon, Yoon - Seong; Kim, Dong Wook; Lee, Jae - Hak; Walters, Ronald A; Hug, Anwar; Colwell, Rita R

    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 define pathogenic V

  19. Outer Membrane Vesicles Mediate Transport of Biologically Active Vibrio cholerae Cytolysin (VCC) from V. cholerae Strains

    PubMed Central

    Elluri, Sridhar; Enow, Constance; Vdovikova, Svitlana; Rompikuntal, Pramod K.; Dongre, Mitesh; Carlsson, Sven; Pal, Amit; Uhlin, Bernt Eric; Wai, Sun Nyunt

    2014-01-01

    Background 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. Methodology/Principal Findings 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. Conclusion/Significance Biological assays of OMVs from the V. cholerae strain V:5/04 demonstrated that OMV-associated VCC is indeed biologically active and

  20. A novel method to combat the cholera epidemic among the Romanian Army during the Balkan War - 1913.

    PubMed

    Leasu, Florin; Nemet, Codruta; Borzan, Cristina; Rogozea, Liliana

    2015-01-01

    The history of cholera, a specific infection caused by Vibrio Cholerae, starts in ancient times. The sixth pandemic that began in 1899 and lasted until 1923, started in India and came to Eastern Europe through Russia. The expansion of the epidemic in the Balkans was facilitated both by the 2 Balkan Wars and the First World War. Romania, as a participant in these wars was affected by cholera, which was especially common among the army during the Balkan War. If the original source of the cholera issue is still controversial, both Romanians and Bulgarians accusing each other of being the basis of the outbreaks south of the Danube, it is widely recognized that the extent of the disease was facilitated by the sanitary conditions of food preparation and drinking water sources among both Romanian soldiers and in the civilian population. Under these conditions, in addition to numerous measures against cholera taken by the Ministry of War, Prof. I. Cantacuzino successfully experiments outbreak vaccination for the first time in the world with a vaccine prepared by himself and his collaborators. The vaccine containing 25 breeds of vibriones was a success in terms of rapid development of a preparation, the application of which was achieved through a quick campaign and proved extremely efficient, imposing the Romanian method as an effective way to combat a disease in full outbreak. PMID:26203545

  1. Effect of LexA on Chromosomal Integration of CTXϕ in Vibrio cholerae

    PubMed Central

    Pant, Archana; Anbumani, D; Bag, Satyabrata; Mehta, Ojasvi; Kumar, Pawan; Saxena, Shruti; Nair, G. Balakrish

    2015-01-01

    ABSTRACT The genesis of toxigenic Vibrio cholerae involves acquisition of CTXϕ, a single-stranded DNA (ssDNA) filamentous phage that encodes cholera toxin (CT). The phage exploits host-encoded tyrosine recombinases (XerC and XerD) for chromosomal integration and lysogenic conversion. The replicative genome of CTXϕ produces ssDNA by rolling-circle replication, which may be used either for virion production or for integration into host chromosome. Fine-tuning of different ssDNA binding protein (Ssb) levels in the host cell is crucial for cellular functioning and important for CTXϕ integration. In this study, we mutated the master regulator gene of SOS induction, lexA, of V. cholerae because of its known role in controlling levels of Ssb proteins in other bacteria. CTXϕ integration decreased in cells with a ΔlexA mutation and increased in cells with an SOS-noninducing mutation, lexA (Ind−). We also observed that overexpression of host-encoded Ssb (VC0397) decreased integration of CTXϕ. We propose that LexA helps CTXϕ integration, possibly by fine-tuning levels of host- and phage-encoded Ssbs. IMPORTANCE Cholera toxin is the principal virulence factor responsible for the acute diarrheal disease cholera. CT is encoded in the genome of a lysogenic filamentous phage, CTXϕ. Vibrio cholerae has a bipartite genome and harbors single or multiple copies of CTXϕ prophage in one or both chromosomes. Two host-encoded tyrosine recombinases (XerC and XerD) recognize the folded ssDNA genome of CTXϕ and catalyze its integration at the dimer resolution site of either one or both chromosomes. Fine-tuning of ssDNA binding proteins in host cells is crucial for CTXϕ integration. We engineered the V. cholerae genome and created several reporter strains carrying ΔlexA or lexA (Ind−) alleles. Using the reporter strains, the importance of LexA control of Ssb expression in the integration efficiency of CTXϕ was demonstrated. PMID:26503849

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

    PubMed Central

    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

  3. Fish as Reservoirs and Vectors of Vibrio cholerae

    PubMed Central

    Senderovich, Yigal; Izhaki, Ido; Halpern, Malka

    2010-01-01

    Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5×103 V. cholerae cfu per 1 gr intestine content—high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses. PMID:20066040

  4. Updated Global Burden of Cholera in Endemic Countries

    PubMed Central

    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

  5. Role of Vibrio cholerae neuraminidase in the function of cholera toxin.

    PubMed Central

    Galen, J E; Ketley, J M; Fasano, A; Richardson, S H; Wasserman, S S; Kaper, J B

    1992-01-01

    Vibrio cholerae neuraminidase (NANase) is hypothesized to act synergistically with cholera toxin (CT) and increase the severity of a secretory response by increasing the binding and penetration of CT to enterocytes. To test this hypothesis, the NANase gene (nanH) from V. cholerae Ogawa 395 was first cloned and sequenced. Isogenic wild-type and NANase- V. cholerae 395 strains were then constructed by using suicide vector-mediated mutagenesis. The influence of NANase on CT binding and penetration was examined in vitro by using culture filtrates from these isogenic strains. Fluorescence due to binding of fluorescein-conjugated CT to C57BL/6 and C3H mouse fibroblasts exposed to NANase+ filtrates increased five- and eightfold, respectively, relative to that with NANase- filtrates. In addition, NANase+ filtrates increased the short-circuit current measured in Ussing chambers 65% relative to that with NANase- filtrates, although this difference decreased as production of CT increased. The role of NANase in V. cholerae pathogenesis was examined in vivo by intragastric inoculation of the isogenic strains into CD1 suckling mice. No difference in fluid accumulation ratios was seen at doses of 10(4) to 10(8) CFU, but NANase+ strains produced 18% higher fluid accumulation ratios at 10(9) CFU than NANase- strains when inoculated into nonfasted suckling mice. It is concluded that NANase plays a subtle but significant role in the binding and uptake of CT by susceptible cells under defined conditions. Images PMID:1730470

  6. Progress towards development of a cholera subunit vaccine.

    PubMed

    Taylor, Ronald K; Kirn, Thomas J; Bose, Niranjan; Stonehouse, Emily; Tripathi, Shital A; Kovác, Pavol; Wade, William F

    2004-07-01

    Cholera, an enteric disease that can reach pandemic proportions, remains a world-wide problem that is positioned to increase in incidence as changes in global climate or armed conflict spawn the conditions that enhance transmission to humans and, thus, precipitate epidemic cholera. An effective subunit cholera vaccine that can provide protective immunity with one parenteral immunization would be a major advantage over the existing oral vaccines that can require two doses for optimal protection. The existing vaccines are clearly effective in some settings, but are less so in others, especially with respect to specific groups such as young (2-5 years) children. In our efforts to develop a cholera subunit vaccine, we focused on two Vibrio cholerae antigens, LPS (lipopolysaccharide) and TCP (toxin co-regulated pilus), that are known to induce protective antibodies in animal models and, in the case of anti-LPS antibodies, to be associated with clinical protection of V. cholerae exposed or vaccinated individuals. This review discusses the current cholera vaccines and compares the advantages of a cholera subunit vaccine to that of the whole cell vaccines. We discuss the possible subunit antigens and prospective targeted use of a subunit cholera vaccine. PMID:17191897

  7. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... may lead to shock, renal failure, cardiovascular collapse, and death. (b) Classification. Class II.... Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and...

  8. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... may lead to shock, renal failure, cardiovascular collapse, and death. (b) Classification. Class II.... Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and...

  9. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... may lead to shock, renal failure, cardiovascular collapse, and death. (b) Classification. Class II.... Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and...

  10. Modern Cholera in the Americas: An Opportunistic Societal Infection

    PubMed Central

    Lee, Patrick T.

    2013-01-01

    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. PMID:24028256

  11. Recombination shapes the structure of an environmental Vibrio cholerae population.

    PubMed

    Keymer, Daniel P; Boehm, Alexandria B

    2011-01-01

    Vibrio cholerae consists of pathogenic strains that cause sporadic gastrointestinal illness or epidemic cholera disease and nonpathogenic strains that grow and persist in coastal aquatic ecosystems. Previous studies of disease-causing strains have shown V. cholerae to be a primarily clonal bacterial species, but isolates analyzed have been strongly biased toward pathogenic genotypes, while representing only a small sample of the vast diversity in environmental strains. In this study, we characterized homologous recombination and structure among 152 environmental V. cholerae isolates and 13 other putative Vibrio isolates from coastal waters and sediments in central California, as well as four clinical V. cholerae isolates, using multilocus sequence analysis of seven housekeeping genes. Recombinant regions were identified by at least three detection methods in 72% of our V. cholerae isolates. Despite frequent recombination, significant linkage disequilibrium was still detected among the V. cholerae sequence types. Incongruent but nonrandom associations were observed for maximum likelihood topologies from the individual loci. Overall, our estimated recombination rate in V. cholerae of 6.5 times the mutation rate is similar to those of other sexual bacteria and appears frequently enough to restrict selection from purging much of the neutral intraspecies diversity. These data suggest that frequent recombination among V. cholerae may hinder the identification of ecotypes in this bacterioplankton population. PMID:21075874

  12. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... may lead to shock, renal failure, cardiovascular collapse, and death. (b) Classification. Class II.... Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and...

  13. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and electrolyte... may lead to shock, renal failure, cardiovascular collapse, and death. (b) Classification. Class...

  14. Active surveillance for Vibrio cholerae O1 and vibriophages in sewage water as a potential tool to predict cholera outbreaks.

    PubMed Central

    Madico, G; Checkley, W; Gilman, R H; Bravo, N; Cabrera, L; Calderon, M; Ceballos, A

    1996-01-01

    The 1991 Peruvian cholera epidemic has thus far been responsible for 600,000 cholera cases in Peru. In an attempt to design a cholera surveillance program in the capital city of Lima, weekly sewage samples were collected between August 1993 and May 1996 and examined for the presence of Vibrio cholerae O1 bacteria and V. cholerae O1 bacteriophages (i.e., vibriophages). During the 144 weeks of surveillance, 6,323 cases of clinically defined cholera were recorded in Lima. We arbitrarily defined an outbreak as five or more reported cases of cholera in a week. The odds of having an outbreak were 7.6 times greater when V. cholerae O1 was present in sewage water during the four previous weeks compared with when it was not (P < 0.001). Furthermore, the odds of having an outbreak increased as the number of V. cholerae O1 isolations during the previous 4 weeks increased (P < 0.001). The odds of having an outbreak were 2.4 times greater when vibriophages were present in sewage water during the four previous weeks compared with when they were not, but this increase was not statistically significant (P = 0.15). The odds of having an outbreak increased as the number of vibriophage isolations during the previous 4 weeks increased (P < 0.05). The signaling of a potential cholera outbreak 1 month in advance may be a valuable tool for implementation of preventive measures. In Peru, active surveillance for V. cholerae O1 and possibly vibriophages in sewage water appears to be a feasible and effective means of predicting and outbreak of cholera. PMID:8940432

  15. Comparative microscopy study of Vibrio cholerae flagella

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:24699521

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

    PubMed Central

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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). Results 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

  19. Single-Dose Doxycycline for Cholera

    PubMed Central

    Sack, David A.; Islam, Sirajul; Rabbani, Hassan; Islam, Asma

    1978-01-01

    To determine the efficacy of single-dose doxycycline in the treatment of cholera, we carried out a randomized prospective trial in 65 patients. Treatment consisted of either a single dose of 200 mg of doxycycline (or 4 mg/kg in patients less than 15 years old) or multiple doses of doxycycline, 500 mg over 4 days (or 10 mg/kg in patients less than 15 years old). There were no differences between the groups in the volumes of intravenous fluid required, volumes of diarrheal stool, or durations of diarrhea. The mean duration of positive stool cultures for Vibrio cholerae was similar for the two groups, although in both groups several patients continued to excrete Vibrios in the stool for more than 3 days. Blood levels of antibiotic demonstrated that the doxycycline was absorbed in spite of the rapid transit time associated with severe diarrhea. These results suggest that although tetracycline remains the drug of choice for cholera, doxycycline is a reasonable alternative, and that a single dose of 200 mg (4 mg/kg in children) is effective clinically. PMID:708024

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

    PubMed Central

    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

  1. Synthetic multivalent ligands for cholera & cholera-like toxins: Protected cyclic neoglycopeptides.

    PubMed

    Kumar, Vajinder; Yadav, Narender; Kartha, K P Ravindranathan

    2016-08-01

    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. PMID:27309341

  2. Impact of Air Temperature and SST Variability on Cholera Incidence in Southeastern Africa, 1971-2006

    NASA Astrophysics Data System (ADS)

    Paz, Shlomit

    2010-05-01

    Poisson regression model is suggested: log{E(CHOLt)} = b0+b1×Xt+b2×Xt-1 where: CHOLt = the number of new cases of cholera in year t Xt / Xt-1 = the climate covariate measured in year t/t-1. (b0,b1) = the coefficients. A first order autocorrelation, AR1 = cor(Yt, Yt-1) is taken into account in the estimation using Generalized Estimating Equations. b1 and b2 quantify the association of CHOL and X, i.e. if Xt or Xt-1 increase by one unit, the mean of Yt is expected to increase in exp{b1} or exp{b2} times, respectively (multiplicative model). The results showed a significant exponential increase of cholera rates in humans during the study period, with an estimate of exp(b1)=1.08 (p-value = 0.02). Associations have been found between the annual increase of the air temperature in southeastern Africa and the cholera incidence in the same area. Linkages were found also for a wider scale, with the air temperature anomaly of the Southern Hemisphere, with an estimate of exp(b1)=1.18 (p-value = 0.04) and exp(b1)=1.26 (p-value = 0.006) for the previous year. Significant linkages were detected between the annual cholera rate and the annual western Indian Ocean' SST , with exp(b1) = 1.31 (p-value = 0.01) for the current year and exp(b1) = 1.23 (p-value = 0.05) for the previous year. Linkages were found also for the hemispheric scale, with the SST anomaly. The increase of global temperature may influence the temporal fluctuations of cholera, as well as potentially increasing the frequency and duration of its outbreaks. Despite future uncertainty, the climate variability has to be considered in predicting further cholera outbreaks in Africa. This may help to promote better, more efficient preparedness. For more details: Paz, S. 2010. Impact of Temperature Variability on Cholera Incidence in Southeastern Africa, 1971-2006. EcoHealth, in press.

  3. Functional Analysis of Bacteriophage Immunity through a Type I-E CRISPR-Cas System in Vibrio cholerae and Its Application in Bacteriophage Genome Engineering

    PubMed Central

    Box, Allison M.; McGuffie, Matthew J.; O'Hara, Brendan J.

    2015-01-01

    ABSTRACT The classical and El Tor biotypes of Vibrio cholerae serogroup O1, the etiological agent of cholera, are responsible for the sixth and seventh (current) pandemics, respectively. A genomic island (GI), GI-24, previously identified in a classical biotype strain of V. cholerae, is predicted to encode clustered regularly interspaced short palindromic repeat (CRISPR)-associated proteins (Cas proteins); however, experimental evidence in support of CRISPR activity in V. cholerae has not been documented. Here, we show that CRISPR-Cas is ubiquitous in strains of the classical biotype but excluded from strains of the El Tor biotype. We also provide in silico evidence to suggest that CRISPR-Cas actively contributes to phage resistance in classical strains. We demonstrate that transfer of GI-24 to V. cholerae El Tor via natural transformation enables CRISPR-Cas-mediated resistance to bacteriophage CP-T1 under laboratory conditions. To elucidate the sequence requirements of this type I-E CRISPR-Cas system, we engineered a plasmid-based system allowing the directed targeting of a region of interest. Through screening for phage mutants that escape CRISPR-Cas-mediated resistance, we show that CRISPR targets must be accompanied by a 3′ TT protospacer-adjacent motif (PAM) for efficient interference. Finally, we demonstrate that efficient editing of V. cholerae lytic phage genomes can be performed by simultaneously introducing an editing template that allows homologous recombination and escape from CRISPR-Cas targeting. IMPORTANCE Cholera, caused by the facultative pathogen Vibrio cholerae, remains a serious public health threat. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) provide prokaryotes with sequence-specific protection from invading nucleic acids, including bacteriophages. In this work, we show that one genomic feature differentiating sixth pandemic (classical biotype) strains from seventh pandemic (El Tor

  4. Phenotypic and Genetic Heterogeneity in Vibrio cholerae O139 Isolated from Cholera Cases in Delhi, India during 2001–2006

    PubMed Central

    Ghosh, Raikamal; Sharma, Naresh C.; Halder, Kalpataru; Bhadra, Rupak K.; Chowdhury, Goutam; Pazhani, Gururaja P.; Shinoda, Sumio; Mukhopadhyay, Asish K.; Nair, G. Balakrish; Ramamurthy, Thadavarayan

    2016-01-01

    Incidence of epidemic Vibrio cholerae serogroup O139 has declined in cholera endemic countries. However, sporadic cholera caused by V. cholerae O139 with notable genetic changes is still reported from many regions. In the present study, 42 V. cholerae O139 strains isolated from 2001 to 2006 in Delhi, India, were retrospectively analyzed to understand their phenotype and molecular characteristics. The majority of isolates were resistant to ampicillin, furazolidone and nalidixic acid. Though the integrative conjugative element was detected in all the O139 isolates, the 2004–2006 isolates remained susceptible to co-trimoxazole, chloramphenicol, and streptomycin. Cholera toxin genotype 1 was present in the majority of the O139 isolates while few had type 3 or a novel type 4. In the cholera toxin encoding gene (ctx) restriction fragment length polymorphism, the majority of the isolates harbored three copies of CTX element, of which one was truncated. In this study, the ctx was detected for the first time in the small chromosome of V. cholerae O139 and one isolate harbored 5 copies of CTX element, of which 3 were truncated. The ribotype BII pattern was found in most of the O139 isolates. Three V. cholerae O139 isolated in 2001 had a new ribotype BVIII. Pulsed-field gel electrophoresis analysis revealed clonal variation in 2001 isolates compared to the 2004–2006 isolates. Molecular changes in V. cholerae O139 have to be closely monitored as this information may help in understanding the changing genetic features of this pathogen in relation to the epidemiology of cholera. PMID:27555841

  5. Phenotypic and Genetic Heterogeneity in Vibrio cholerae O139 Isolated from Cholera Cases in Delhi, India during 2001-2006.

    PubMed

    Ghosh, Raikamal; Sharma, Naresh C; Halder, Kalpataru; Bhadra, Rupak K; Chowdhury, Goutam; Pazhani, Gururaja P; Shinoda, Sumio; Mukhopadhyay, Asish K; Nair, G Balakrish; Ramamurthy, Thadavarayan

    2016-01-01

    Incidence of epidemic Vibrio cholerae serogroup O139 has declined in cholera endemic countries. However, sporadic cholera caused by V. cholerae O139 with notable genetic changes is still reported from many regions. In the present study, 42 V. cholerae O139 strains isolated from 2001 to 2006 in Delhi, India, were retrospectively analyzed to understand their phenotype and molecular characteristics. The majority of isolates were resistant to ampicillin, furazolidone and nalidixic acid. Though the integrative conjugative element was detected in all the O139 isolates, the 2004-2006 isolates remained susceptible to co-trimoxazole, chloramphenicol, and streptomycin. Cholera toxin genotype 1 was present in the majority of the O139 isolates while few had type 3 or a novel type 4. In the cholera toxin encoding gene (ctx) restriction fragment length polymorphism, the majority of the isolates harbored three copies of CTX element, of which one was truncated. In this study, the ctx was detected for the first time in the small chromosome of V. cholerae O139 and one isolate harbored 5 copies of CTX element, of which 3 were truncated. The ribotype BII pattern was found in most of the O139 isolates. Three V. cholerae O139 isolated in 2001 had a new ribotype BVIII. Pulsed-field gel electrophoresis analysis revealed clonal variation in 2001 isolates compared to the 2004-2006 isolates. Molecular changes in V. cholerae O139 have to be closely monitored as this information may help in understanding the changing genetic features of this pathogen in relation to the epidemiology of cholera. PMID:27555841

  6. Avian cholera and organochlorine residues in an American oystercatcher

    USGS Publications Warehouse

    Blus, L.J.; Locke, L.N.; Cromartie, E.

    1978-01-01

    Pasteurella multocida, the causative bacterium of avian cholera, was isolated from cultures of the liver and heart blood of a female, adult American oystercatcher (Haematopus palliatus) found dead on the Cape Romain National Wildlife Refuge, South Carolina, in May 1973. This is apparently the first record of avian cholera in the oystercatcher. Low levels of DDE were identified in tissues of the oystercatcher.

  7. Risk Factors Early in the 2010 Cholera Epidemic, Haiti

    PubMed Central

    Cartwright, Emily; Loharikar, Anagha; Routh, Janell; Gaines, Joanna; Fouché, Marie-Délivrance Bernadette; Jean-Louis, Reginald; Ayers, Tracy; Johnson, Dawn; Tappero, Jordan W.; Roels, Thierry H.; Archer, W. Roodly; Dahourou, Georges A.; Mintz, Eric; Quick, Robert; Mahon, Barbara E.

    2011-01-01

    During the early weeks of the cholera outbreak that began in Haiti in October 2010, we conducted a case–control study to identify risk factors. Drinking treated water was strongly protective against illness. Our results highlight the effectiveness of safe water in cholera control. PMID:22099118

  8. PREVENTION OF WATERBORNE CHOLERA IN THE UNITED STATES

    EPA Science Inventory

    Since the outbreak of cholera in Peru in January 1991, the disease has spread to other Latin-American countries and on several occasions has been imported into the United States. n order to assess the risk of transmission of cholera by water in the United States, an ad hoc commit...

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

    PubMed Central

    Osei, Frank B; Duker, Alfred A

    2008-01-01

    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 < 0.001. Furthermore, A Mantel-Haenszel Chi square for trend analysis reflected a direct spatial relationship between cholera and urbanization (χ2 = 2995.5, P < 0.0001), overcrowding (χ2 = 1757.2, P < 0.0001), and an inverse relationship between cholera and order of neighborhood with Kumasi Metropolis (χ2 = 831.38, P < 0.0001). Conclusion The results suggest that high urbanization, high overcrowding, and neighborhood with Kumasi Metropolis are the most important predictors of cholera in Ashanti region. PMID:18700026

  10. Understanding the Hydrology of Cholera in South Asia

    NASA Astrophysics Data System (ADS)

    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.

  11. Risk Factors for Sustained Cholera Transmission, Juba County, South Sudan, 2014.

    PubMed

    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. PMID:26402715

  12. Spread of Cholera with Newer Clones of Vibrio cholerae O1 El Tor, Serotype Inaba, in India

    PubMed Central

    Dutta, B.; Ghosh, R.; Sharma, N. C.; Pazhani, G. P.; Taneja, N.; Raychowdhuri, A.; Sarkar, B. L.; Mondal, S. K.; Mukhopadhyay, A. K.; Nandy, R. K.; Bhattacharya, M. K.; Bhattacharya, S. K.; Ramamurthy, T.

    2006-01-01

    During 2004 and 2005, cholera was recorded in 15 states of India, with 7 outbreaks. The newly emerged Vibrio cholerae O1 Inaba had a different antibiogram and ribotype, different pulsotypes, and different mutations in the wbeT gene. Due to the absence of serogroup O139, the Inaba serotype may have acquired the potential to affect the population at large. PMID:16954282

  13. Multi-locus variable number tandem repeat analysis of Vibrio cholerae isolates from 2012 to 2013 cholera outbreaks in Iran.

    PubMed

    Ranjbar, R; Sadeghy, J; Shokri Moghadam, M; Bakhshi, B

    2016-08-01

    Cholera remains to be an international threat, with high rates of illness and death. In 2012 and 2013, two cholera outbreak happened in Iran, affecting lots of people. Vibrio cholerae O1 was confirmed as the etiological agent. Source identification and controlling the spread of the cholera disease are two critical approaches in cholera outbreaks. In this study, thirty V. cholerae O1 isolates were selected and has been evaluated for antimicrobial resistant as well as molecular typing by multilocus variable-number tandem-repeat analysis (MLVA) method. Twenty-nine (97%) isolates were sero-grouped as El Tor (one isolate was classical) and 100% were related to Inaba serotype. All of the isolates were susceptible to ciprofloxacin, chloramphenicol, ampicillin and gentamicin. On the other hand, 60% of the isolates were MDR (resistant to 3 or more classes). There were three resistance patterns. The most prevalent pattern was resistance to streptomycin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline (ST-SXT-E-T) which was seen in 50% of isolates. Using MLVA method 14 MLVA types were identified. MLVA type 2 (5-7-7-16-15) accounted for 43% of isolates. Isolates with the same genotype often did not have the same antibiogram. Overall, the data indicate that the Iranian V. cholerae were MDR and clonaly related. Furthermore, the results of this study shows that MLVA can be used as useful method for V. cholerae genotyping in epidemiological investigations. PMID:27247094

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

    PubMed Central

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

    2012-01-01

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

  15. Zebrafish as a Natural Host Model for Vibrio cholerae Colonization and Transmission

    PubMed Central

    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

  16. Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  17. Cholera toxin - a foe & a friend.

    PubMed

    Sanchez, Joaquin; Holmgren, Jan

    2011-02-01

    After De΄s pivotal demonstration in 1959 of a diarrhoeogenic exo-enterotoxin in cell-free culture filtrates from Vibrio cholerae (of classical biotype), much insight has been gained about cholera toxin (CT), which is arguably now the best known of all microbial toxins. The subunit structure and function of CT, its receptor (the GM1 ganglioside), and its effects on the cyclic AMP system and on intestinal secretion were defined in the 1970s, and the essential aspects of the genetic organization in the 1980s. Recent findings have generated additional perspectives. The 3D-crystal structure of CT has been established, the CT-encoding operon has been shown to be carried by a non-lytic bacteriophage, and in depth knowledge has been gained on how the bacterium controls CT gene expression in response to cell density and various environmental signals. The mode of entry into target cells and the intracellular transport of CT are becoming clearer. CT has become the prototype enterotoxin and a widely used tool for elucidating important aspects of cell biology and physiology, e.g., cell membrane receptors, the cyclic AMP system, G proteins, as well as normal and pathological ion transport mechanisms. In immunology, CT has emerged as a potent, widely used experimental adjuvant, and the strong oral-mucosal immunogenicity of the non-toxic B-subunit (CTB) has led to the use of CTB as a protective antigen together with killed vibrios in a widely licensed oral cholera vaccine. CTB has also been shown to promote immunological tolerance against certain types of mucosally co-administered antigens, preferably tissue antigens linked to the CTB molecule; this has stimulated research and development to use CTB in this context for treatment of autoimmune and allergic diseases. In summary, in the 50 years after De΄s discovery of CT, this molecule has emerged from being the cholera patient΄s "foe" to also becoming a highly useful scientist΄s "friend". PMID:21415489

  18. Genetic evidence that the Vibrio cholerae monolayer is a distinct stage in biofilm development

    PubMed Central

    Moorthy, Sudha; Watnick, Paula I.

    2008-01-01

    Summary Biofilm development is conceived as a developmental process in which free swimming cells attach to a surface, first transiently and then permanently, as a single layer. This monolayer of immobilized cells gives rise to larger cell clusters that eventually develop into the biofilm, a three-dimensional structure consisting of large pillars of bacteria interspersed with water channels. Previous studies have shown that efficient development of the Vibrio cholerae biofilm requires a combination of pili, flagella and exopolysaccharide. Little is known, however, regarding the requirements for monolayer formation by wild-type V. cholerae. In this work, we have isolated the wild-type V. cholerae monolayer and demonstrated that the environmental signals, bacterial structures, and transcription profiles that induce and stabilize the monolayer state are unique. Cells in a monolayer are specialized to maintain their attachment to a surface. The surface itself activates mannose-sensitive haemagglutinin type IV pilus (MSHA)-mediated attachment, which is accompanied by repression of flagellar gene transcription. In contrast, cells in a biofilm are specialized to maintain intercellular contacts. Progression to this stage occurs when exopolysaccharide synthesis is induced by environmental monosaccharides. We propose a model for biofilm development in natural environments in which cells form a stable monolayer on a surface. As biotic surfaces are degraded with subsequent release of carbohydrates, the monolayer develops into a biofilm. PMID:15066042

  19. The Outer Surface Lipoprotein VolA Mediates Utilization of Exogenous Lipids by Vibrio cholerae

    PubMed Central

    Pride, Aaron C.; Herrera, Carmen M.; Guan, Ziqiang; Giles, David K.; Trent, M. Stephen

    2013-01-01

    ABSTRACT Previous work from our laboratory showed that the Gram-negative aquatic pathogen Vibrio cholerae can take up a much wider repertoire of fatty acids than other Gram-negative organisms. The current work elaborated on the ability of V. cholerae to exploit an even more diverse pool of lipid nutrients from its environment. We have demonstrated that the bacterium can use lysophosphatidylcholine as a metabolite for growth. Using a combination of thin-layer chromatography and mass spectrometry, we also showed that lysophosphatidylcholine-derived fatty acid moieties can be used for remodeling the V. cholerae membrane architecture. Furthermore, we have identified a lysophospholipase, VolA (Vibrio outer membrane lysophospholipase A), required for these activities. The enzyme is well conserved in Vibrio species, is coexpressed with the outer membrane fatty acid transporter FadL, is one of very few surface-exposed lipoprotein enzymes to be identified in Gram-negative bacteria and the first instance of a surface lipoprotein phospholipase. We propose a model whereby the bacterium efficiently couples the liberation of fatty acid from lysophosphatidylcholine to its subsequent metabolic uptake. An expanded ability to scavenge diverse environmental lipids at the bacterial surface increases overall bacterial fitness and promotes homeoviscous adaptation through membrane remodeling. PMID:23674613

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

    PubMed

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

    1984-09-01

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

  1. Molecular tools in understanding the evolution of Vibrio cholerae

    PubMed Central

    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

  2. [Cholera epidemics on Reunion Island during the 19th century].

    PubMed

    Gaüzère, B-A; Aubry, P

    2012-01-01

    The first cholera outbreak on Bourbon Island (now Reunion Island) was recorded in January 1820. The disease was imported from Mauritius Island aboard the steamer Pivert. The epidemic began on Mauritius in November 1819 after the English frigate, La Topaze, called from Calcutta, India. Dr. François Vinson demonstrated the transmissibility of cholera during this epidemic. Drastic sanitary measures spared Reunion from the two epidemics on Mauritius Island, in 1854 and 1856. The second outbreak of cholera on Reunion Island was recorded on March 6, 1859. The disease was introduced from East Africa by the steamer Mascareignes, which carried indentured servants. The captain (d'Agnel) et the supercargo (Menon) of the steamer claimed to the doctor who boarded the ship before landing that no passengers or crew had had cholera, in flagrant contradiction to the autopsy report issued by Navy surgeon Alfred Vaillant, who had concluded that cholera was present when the vessel left the African coast. This report was withheld from the boarding physician. Cholera spread quickly on the island and affected the poorest people, especially freed slaves, most severely. Dr. Petit, the chief Navy Physician and Director of the Health Department, obtained a confession by Menon about the fraudulent statements. On January 24, 1860, a trial for public health endangerment began on Reunion Island; it ended on February 1 with a not-guilty verdict, based largely on the testimony of several island doctors that cholera was not contagious. PMID:22992340

  3. Mucosal immunologic responses in cholera patients in Bangladesh.

    PubMed

    Uddin, Taher; Harris, Jason B; Bhuiyan, Taufiqur Rahman; Shirin, Tahmina; Uddin, Muhammad Ikhtear; Khan, Ashraful Islam; Chowdhury, Fahima; LaRocque, Regina C; Alam, Nur Haque; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi

    2011-03-01

    Vibrio cholerae O1 causes dehydrating diarrhea with a high mortality rate if untreated. The infection also elicits long-term protective immunity. Since V. cholerae is noninvasive, mucosal immunity is likely important for protection. In this study, we compared humoral immune responses in the duodenal mucosa and blood of cholera patients at different time points after the onset of disease and compared them with those of healthy controls (HCs). Immune responses to lipopolysaccharide (LPS) and the recombinant cholera toxin B subunit (rCTB) were assessed by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Significant increases in V. cholerae LPS-specific IgA and IgG antibody levels were seen in duodenal extracts on day 30, but the levels decreased to baseline by day 180; plasma V. cholerae LPS-specific IgA levels remained elevated longer. Levels of mucosal CTB antibodies also peaked on day 30, but the increase reached statistical significance only for IgG. A significant correlation was found between the CTB antibody-secreting cell (ASC) response in the circulatory system on day 7 and subsequent CTB-specific IgA levels in duodenal extracts on day 30 and the numbers of CTB-specific IgA ASCs in duodenal tissues on day 180. The proportion (0.07%) of mucosal V. cholerae LPS IgA ASCs peaked on day 30 and remained elevated through day 180 compared to that of HCs (P = 0.03). These results suggest that protective immunity against V. cholerae is not likely mediated by the constitutive secretion of antibodies at the mucosal surface; our results are consistent with those of other studies that suggest instead that anamnestic immune responses of mucosal lymphocytes may play a major role in protection against cholera. PMID:21248157

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  5. Survival of Vibrio cholerae O1 on fomites.

    PubMed

    Farhana, Israt; Hossain, Zenat Zebin; Tulsiani, Suhella Mohan; Jensen, Peter Kjær Mackie; Begum, Anowara

    2016-09-01

    It is well established that the contamination sources of cholera causing bacteria, Vibrio cholerae, are water and food, but little is known about the transmission role of the fomites (surfaces that can carry pathogens) commonly used in households. In the absence of appropriate nutrients or growth conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass, plastic, cloth and several types of metals under laboratory conditions. The fomites were inoculated with an outbreak strain of V. cholerae and its culturability was examined by drop plate count method at 30 min intervals for up to 6 h. For molecular detection, the viable/dead stain ethidium monoazide (EMA) which inhibits amplification of DNA from dead cells was used in combination with real-time polymerase chain reaction (EMA-qPCR) for direct quantitative analyses of viable V. cholerae at 2, 4, 6, 24 h and 7 day time intervals. Results showed that V. cholerae on glass and aluminum surfaces lost culturability within one hour after inoculation but remained culturable on cloth and wood for up to four hours. VBNC V. cholerae on dry fomite surfaces was detected and quantified by EMA-qPCR even 7 days after inoculation. In conclusion, the prolonged survival of V. cholerae on various household fomites may play vital role in cholera transmission and needs to be further investigated. PMID:27430513

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

    PubMed

    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. PMID:22952995

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

    PubMed Central

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

    2012-01-01

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

  8. Cholera toxin interactions with lipid bilayers.

    PubMed

    Tosteson, M T; Tosteson, D C; Rubnitz, J

    1980-01-01

    The purpose of the experiments described in this paper was to assess the binding of cholera toxin to bilayers containing its receptor, the monosialoganglioside, GMl. The assay was based on the fact that GMl confers on the bilayer a negative surface charge. The magnitude of this surface charge was estimated by measuring the electrical conductance (G) of the bilayers exposed to nonactin-K+ under conditions where G is directly proportional to the potassium concentration in the aqueous solutions immediatey adjacent to the membrane surface. When bilayers were formed from mixtures of GMl and glycerolmonooleate (GMO), it was found that the molar ratio of the lipids in the bilayer was the same as that in the membrane forming solution. It was further found that cholera toxin or the binding subunit of the toxin (choleragenoid) bind to GMO bilayers containing GMl (but not to GMO bilayers containing phosphatidyl serine or disialoganglioside GDla). The value of the apparent dissociation constant for the binding of choleragen to its receptor was found to be 10(-11) M, comparable to values found in intact cells. PMID:6933823

  9. Antibiotic therapy of cholera in children*

    PubMed Central

    Lindenbaum, John; Greenough, William B.; Islam, M. R.

    1967-01-01

    In a controlled trial of the effects of oral antibiotics in treating cholera in children in Dacca, East Pakistan, tetracycline was the most effective of 4 antibiotics tested in reducing stool volume, intravenous fluid requirement, and the duration of diarrhoea and positive stool culture. Increasing the duration of tetracycline therapy from 2 to 4 days, or increasing the total dose administered, resulted in shorter duration of positive culture, but did not affect stool volume or duration of diarrhoea. Only 1% of the children receiving tetracycline had diarrhoea for more than 4 days. Tetracycline was significantly more effective than intravenous fluid therapy alone, regardless of severity of disease. Chloramphenicol, while also effective, was inferior to tetracycline. Streptomycin and paromomycin exerted little or no effect on the course of illness or duration of positive culture. Therapeutic failures with these drugs were not due to the development of bacterial resistance. From these findings, tetracycline appears to be the drug of choice against Vibrio cholerae infection in children. Oral therapy for 48 hours is effective clinically, but is associated with 20% bacteriological relapses when the drug is discontinued; it is not known whether extending the therapy for a week or more would eliminate such relapses. PMID:5301733

  10. Construction and Evaluation of V. cholerae O139 Mutant, VCUSM21P, as a Safe Live Attenuated Cholera Vaccine

    PubMed Central

    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. PMID:24505241

  11. The Mannose-Sensitive Hemagglutinin of Vibrio cholerae Promotes Adherence to Zooplankton

    PubMed Central

    Chiavelli, Deborah A.; Marsh, Jane W.; Taylor, Ronald K.

    2001-01-01

    The bacterium Vibrio cholerae, the etiological agent of cholera, is often found attached to plankton, a property that is thought to contribute to its environmental persistence in aquatic habitats. The V. cholerae O1 El Tor biotype and V. cholerae O139 strains produce a surface pilus termed the mannose-sensitive hemagglutinin (MSHA), whereas V. cholerae O1 classical biotype strains do not. Although V. cholerae O1 classical does not elaborate MSHA, the gene is present and expressed at a level comparable to that of the other strains. Since V. cholerae O1 El Tor and V. cholerae O139 have displaced V. cholerae O1 classical as the major epidemic strains over the last fifteen years, we investigated the potential role of MSHA in mediating adherence to plankton. We found that mutation of mshA in V. cholerae O1 El Tor significantly diminished, but did not eliminate, adherence to exoskeletons of the planktonic crustacean Daphnia pulex. The effect of the mutation was more pronounced for V. cholerae O139, essentially eliminating adherence. Adherence of the V. cholerae O1 classical mshA mutant was unaffected. The results suggest that MSHA is a factor contributing to the ability of V. cholerae to adhere to plankton. The results also showed that both biotypes of V. cholerae O1 utilize factors in addition to MSHA for zooplankton adherence. The expression of MSHA and these additional, yet to be defined, adherence factors differ in a serogroup- and biotype-specific manner. PMID:11425745

  12. Endemic and epidemic dynamics of cholera: the role of the aquatic reservoir

    PubMed Central

    Codeço, Cláudia Torres

    2001-01-01

    Background In the last decades, attention to cholera epidemiology increased, as cholera epidemics became a worldwide health problem. Detailed investigation of V. cholerae interactions with its host and with other organisms in the environment suggests that cholera dynamics is much more complex than previously thought. Here, I formulate a mathematical model of cholera epidemiology that incorporates an environmental reservoir of V. cholerae. The objective is to explore the role of the aquatic reservoir on the persistence of endemic cholera as well as to define minimum conditions for the development of epidemic and endemic cholera. Results The reproduction rate of cholera in a community is defined by the product of social and environmental factors. The importance of the aquatic reservoir depends on the sanitary conditions of the community. Seasonal variations of contact rates force a cyclical pattern of cholera outbreaks, as observed in some cholera-endemic communities. Conclusions Further development on cholera modeling requires a better understanding of V. cholerae ecology and epidemiology. We need estimates of the prevalence of V. cholerae infection in endemic populations as well as a better description of the relationship between dose and virulence. PMID:11208258

  13. Genomic Science in Understanding Cholera Outbreaks and Evolution of Vibrio cholerae as a Human Pathogen

    PubMed Central

    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 CTX–ϕ 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. PMID:24590676

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

    NASA Astrophysics Data System (ADS)

    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 () <1, which would suppress transmission. In the current 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.

  15. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

    PubMed Central

    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

  16. Cholera Outbreak in Grande Comore: 1998-1999.

    PubMed

    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

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

    USGS Publications Warehouse

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

    1992-01-01

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

  18. Inorganic polyphosphate in Vibrio cholerae: genetic, biochemical, and physiologic features.

    PubMed

    Ogawa, N; Tzeng, C M; Fraley, C D; Kornberg, A

    2000-12-01

    Vibrio cholerae O1, biotype El Tor, accumulates inorganic polyphosphate (poly P) principally as large clusters of granules. Poly P kinase (PPK), the enzyme that synthesizes poly P from ATP, is encoded by the ppk gene, which has been cloned from V. cholerae, overexpressed, and knocked out by insertion-deletion mutagenesis. The predicted amino acid sequence of PPK is 701 residues (81.6 kDa), with 64% identity to that of Escherichia coli, which it resembles biochemically. As in E. coli, ppk is part of an operon with ppx, the gene that encodes exopolyphosphatase (PPX). However, unlike in E. coli, PPX activity was not detected in cell extracts of wild-type V. cholerae. The ppk null mutant of V. cholerae has diminished adaptation to high concentrations of calcium in the medium as well as motility and abiotic surface attachment. PMID:11073913

  19. Global dynamics of cholera models with differential infectivity.

    PubMed

    Shuai, Zhisheng; van den Driessche, P

    2011-12-01

    A general compartmental model for cholera is formulated that incorporates two pathways of transmission, namely direct and indirect via contaminated water. Non-linear incidence, multiple stages of infection and multiple states of the pathogen are included, thus the model includes and extends cholera models in the literature. The model is analyzed by determining a basic reproduction number R0 and proving, by using Lyapunov functions and a graph-theoretic result based on Kirchhoff's Matrix Tree Theorem, that it determines a sharp threshold. If R0≤1, then cholera dies out; whereas if R0>1, then the disease tends to a unique endemic equilibrium. When input and death are neglected, the model is used to determine a final size equation or inequality, and simulations illustrate how assumptions on cholera transmission affect the final size of an epidemic. PMID:22001141

  20. Cholera Outbreak in Grande Comore: 1998–1999

    PubMed Central

    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

  1. Cholera in Haiti and Other Caribbean Regions, 19th Century

    PubMed Central

    Szabo, Victoria

    2011-01-01

    Medical journals and other sources do not show evidence that cholera occurred in Haiti before 2010, despite the devastating effect of this disease in the Caribbean region in the 19th century. Cholera occurred in Cuba in 1833–1834; in Jamaica, Cuba, Puerto Rico, St. Thomas, St. Lucia, St. Kitts, Nevis, Trinidad, the Bahamas, St. Vincent, Granada, Anguilla, St. John, Tortola, the Turks and Caicos, the Grenadines (Carriacou and Petite Martinique), and possibly Antigua in 1850–1856; and in Guadeloupe, Cuba, St. Thomas, the Dominican Republic, Dominica, Martinique, and Marie Galante in 1865–1872. Conditions associated with slavery and colonial military control were absent in independent Haiti. Clustered populations, regular influx of new persons, and close quarters of barracks living contributed to spread of cholera in other Caribbean locations. We provide historical accounts of the presence and spread of cholera epidemics in Caribbean islands. PMID:22099117

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

    PubMed Central

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

    2015-01-01

    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. PMID:25802972

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2011-01-01

    The rise in multi-drug resistant Vibrio cholerae strains is a big problem in treatment of patients suffering from severe cholera. Only a few studies have evaluated the potential of natural compounds against V. cholerae. Extracts from plants like ‘neem’, ‘guazuma’, ‘daio’, apple, hop, green tea and elephant garlic have been shown to inhibit bacterial growth or the secreted cholera toxin (CT). However, inhibiting bacterial growth like common antimicrobial agents may also impose selective pressure facilitating development of resistant strains. A natural compound that can inhibit virulence in V. cholerae is an alternative choice for remedy. Recently, some common spices were examined to check their inhibitory capacity against virulence expression of V. cholerae. Among them methanol extracts of red chili, sweet fennel and white pepper could substantially inhibit CT production. Fractionation of red chili methanol extracts indicated a hydrophobic nature of the inhibitory compound(s), and the n-hexane and 90 per cent methanol fractions could inhibit >90 per cent of CT production. Purification and further fractionation revealed that capsaicin is one of the major components among these red chili fractions. Indeed, capsaicin inhibited the production of CT in various V. cholerae strains regardless of serogroups and biotypes. The quantitative reverse transcription real-time PCR assay revealed that capsaicin dramatically reduced the expression of major virulence-related genes such as ctxA, tcpA and toxT but enhanced the expression of hns gene that transcribes a global prokaryotic gene regulator (H-NS). This indicates that the repression of CT production by capsaicin or red chili might be due to the repression of virulence genes transcription by H-NS. Regular intake of spices like red chili might be a good approach to fight against devastating cholera. PMID:21415500

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

    PubMed

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

    2013-01-01

    With increasing population displacement and worsening water insecurity after the 2010 earthquake, Haiti experienced a large cholera outbreak. Our goal was to evaluate the strengths and weaknesses of seven community health facilities' ability to respond to a surge in cholera cases. Since 2010, Catholic Relief Services (CRS) with a number of public and private donors has been working with seven health facilities in an effort to reduce morbidity and mortality from cholera infection. In November 2012, CRS through the Centers for Disease Control and Prevention (CDC)'s support, asked the Johns Hopkins Center for Refugee and Disaster Response to conduct a cholera surge simulation tabletop exercise at these health facilities to improve each facility's response in the event of a cholera surge. Using simulation development guidelines from the Pan American Health Organization and others, a simulation scenario script was produced that included situations of differing severity, supply chain, as well as a surge of patients. A total of 119 hospital staff from seven sites participated in the simulation exercise including community health workers, clinicians, managers, pharmacists, cleaners, and security guards. Clinics that had challenges during the simulated clinical care of patients were those that did not appropriately treat all cholera patients according to protocol, particularly those that were vulnerable, those that would need additional staff to properly treat patients during a surge of cholera, and those that required a better inventory of supplies. Simulation-based activities have the potential to identify healthcare delivery system vulnerabilities that are amenable to intervention prior to a cholera surge. PMID:24481887

  7. Transcript changes in Vibrio cholerae in response to salt stress.

    PubMed

    Fu, Xiuping; Liang, Weili; Du, Pengcheng; Yan, Meiying; Kan, Biao

    2014-01-01

    Vibrio cholerae, which is a serious human intestinal pathogen, often resides and thrives in estuaries but requires major self-regulation to overcome intestinal hyperosmotic stress or high salt stress in water and food. In the present study, we selected multiple O1 and O139 group V. cholerae strains that were isolated from different regions and during different years to study their salt tolerance. Based on the mechanisms that other bacteria use to respond to high salt stress, we selected salt stress-response related genes to study the mechanisms which V. cholerae responds to high salt stress. V. cholerae strains showed salt-resistance characteristics that varied in salt concentrations from 4% to 6%. However, group O1 and group O139 showed no significant difference in the degree of salt tolerance. The primary responses of bacteria to salt stress, including Na(+) exclusion, K(+) uptake and glutamate biosynthesis, were observed in V. cholerae strains. In addition, some sigma factors were up-regulated in V. cholerae strains, suggesting that V. cholerae may recruit common sigma factors to achieve an active salt stress response. However, some changes in gene transcript levels in response to salt stress in V. cholerae were strain-specific. In particular, hierarchical clustering of differentially expressed genes indicated that transcript levels of these genes were correlated with the degree of salt tolerance. Therefore, elevated transcript levels of some genes, including sigma factors and genes involved in peptidoglycan biosynthesis, may be due to the salt tolerance of strains. In addition, high salt-tolerant strains may recruit common as well as additional sigma factors to activate the salt stress response. PMID:25589902

  8. The Role of Cyanobacteria Blooms in Cholera Epidemic in Bangladesh

    NASA Astrophysics Data System (ADS)

    Sagir Ahmed, Md.; Raknuzzaman, Md.; Akther, Hafeza; Ahmed, Sumaiya

    A study was conducted on association of Vibrio cholerae with plankton specially emphasis on cyanobacteria in relation to some physico-chemical parameters in the River Buriganga, Dhaka, from January to December 2002. Monthly abundance of phytoplankton and zooplankton varied from 457 to 14166 and from 169 to 1055 individual L-1, respectively. Monthly average of faecal coliform in water, zooplankton and phytoplankton samples were 3.99x109, 4.54x103 and 4.28x102 (CFU L-1), respectively. During epidemics, toxigenic V. cholerae 01 and 0139 were isolated from the patients as well as from the surface water. V. cholerae 01 and 0139 were also isolated from plankton samples. More over, it was observed that ctx (cholera toxic) positive in water and phytoplankton samples of the river. A bloom of Oscillatoria sp. (1.6x104 individual L-1) occurred in the upper reaches of the River Buriganga in May 2002. Methanol-water extract of bloom sample was analyzed by high performance liquid chromatography with UV detection and Mass Spectrum (MS) detected microcystin-RR. Cyanobacteria are abundant in the aquatic environment of Bangladesh and it was established that V. cholerae maintain a symbiotic relationship with these algae particularly mucilaginous cyanobacteria. During epidemics, patients symptoms included diarrhea, vomiting and hemorrhagic enteritis and in severe cases hemorrhagic diarrhea. So, question has arisen that which is responsible, microcystins or cholera for death of cholera/diarrhea patients in Bangladesh. Future research should be directed to isolate microcystins and cholera toxins from the epidemic areas to clarify the fact.

  9. Risk of Cholera Among Western and Japanese Travelers.

    PubMed

    Wittlinger; Steffen; Watanabe; Handszuh

    1995-09-01

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

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

    PubMed

    Prasad, P V V

    2005-01-01

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

  11. Distribution ofVibrio cholerae in two Florida estuaries.

    PubMed

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

    1983-04-01

    The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries. PMID:24221617

  12. [Phenotypic and genotypic characterization of Vibrio cholerae O1].

    PubMed

    Giono-Cerezo, S; Rodríguez Angeles, M G; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

    1994-01-01

    We made 52180 tests for isolation and identification of toxigenic V. cholerae O1 from rectal swabs and reference strains. We isolated 17.6% V. cholerae O1 strains in 1991, 43.5% in 1992 and 38.9% in 1993. The main serovar in 1991 was Inaba, whereas in 1993 a similar percentage was serovar Ogawa. The phenotype of V. cholerae strains was determined by hemolysis test, Voges-Proskauer test, polymyxin B resistance and phages 4 and 5 resistance. All of the mexican strains were El Tor. There were 2.9-0.75% hemolytic strains from 1991 to 1993, but they were negative when the test was made in tube with human erythrocytes. The resistotypes were performed in 24526 selected strains by Kirby-Bauer method and MIC tests. All of the strains were sensitive, except more than 100 strains isolated in Veracruz that were resistant to tetracycline and doxycycline. Detection of cholera toxin was made by ELISA and on culture of Vero and CHO cells. All the V. cholerae O1 strains were toxigenic. The genotype was determined by PCR and ribotyping. The PCR amplified one 564 pb fragment on V. cholerae O1. The ribotypes of mexican strains were 5 and 6a. PMID:7701133

  13. [Cholera epidemic in Brescia in 1836].

    PubMed

    Vaglia, Alberto

    2013-09-01

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

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

    PubMed

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

    1995-06-01

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

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

    PubMed Central

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

    2014-01-01

    We evaluated World Health Organization (WHO) national water and sanitation coverage levels and the infant mortality rate as predictors of endemic cholera in the 5-year period following water and sanitation coverage estimates using logistic regression, receiver operator characteristic curves, and different definitions of endemicity. Each was a significant predictors of endemic cholera at P < 0.001. Using a value of 250 for annual cases reported in 3 of 5 years, a national water access level of 71% has 65% sensitivity and 65% specificity in predicting endemic cholera, a sanitation access level of 39% has 63% sensitivity and 62% specificity, and an infant mortality rate of 65/1,000 has 67% sensitivity and 69% specificity. Our findings reveal the tradeoff between sensitivity and specificity for these predictors of endemic cholera and highlight the substantial uncertainty in the data. More accurate global surveillance data will enable more precise characterization of the benefits of improved water and sanitation. PMID:25200265

  16. Cholera Outbreaks in Urban Bangladesh In 2011

    PubMed Central

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

    2015-01-01

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

  17. Characterization of tryptophanase from Vibrio cholerae.

    PubMed

    Nuidate, Taiyeebah; Tansila, Natta; Chomchuen, Piraporn; Phattaranit, Phattiphong; Eangchuan, Supachok; Vuddhakul, Varaporn

    2015-01-01

    Tryptophanase (Trpase) is a pyridoxal phosphate (PLP)-dependent enzyme responsible for the production of indole, an important intra- and interspecies signaling molecule in bacteria. In this study, the tnaA gene of Vibrio cholerae coding for VcTrpase was cloned into the pET-20b(+) vector and expressed in Escherichia coli BL21(DE3) tn5:tnaA. Using Ni(2+)-nitrilotriacetic acid (NTA) chromatography, VcTrpase was purified, and it possessed a molecular mass of ∼49 kDa with specific absorption peaks at 330 and 435 nm and a specific activity of 3 U/mg protein. The VcTrpase had an 80 % homology to the Trpase of Haemophilus influenzae and E. coli, but only around 50 % identity to the Trpase of Proteus vulgaris and Porphyromonas gingivalis. The optimum conditions for the enzyme were at pH 9.0 and 45 °C. Recombinant VcTrpase exhibited analogous kinetic reactivity to the EcTrpase with K m and k cat values of 0.612 × 10(-3) M and 5.252 s(-1), respectively. The enzyme catalyzed S-methyl-L-cysteine and S-benzyl-L-cysteine degradation, but not L-phenylalanine and L-serine. Using a site-directed mutagenesis technique, eight residues (Thr52, Tyr74, Arg103, Asp137, Arg230, Lys269, Lys270, and His463) were conserved for maintaining enzyme catalysis. All amino acid substitutions at these sites either eliminated or remarkably diminished Trpase activity. These sites are thus potential targets for the design of drugs to control the V. cholerae Trpase and to further investigate its functions. PMID:25253268

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

    PubMed Central

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

    2016-01-01

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

  19. Epidemiology, determinants and dynamics of cholera in Pakistan: gaps and prospects for future research.

    PubMed

    Naseer, Maliha; Jamali, Tanzil

    2014-11-01

    Cholera is one of the notifiable endemic diseases in Pakistan, but the reporting of cholera cases is still unsatisfactory. Most of the diagnosed cases are never reported to the relevant authorities. In the year 1993 - 2005, the country did not report any single case of cholera to the WHO. The objectives of this review were to understand the epidemiology and to identify the possible determinants of cholera infection in Pakistan. Medscape, Medline, PakMedinet and PubMed, was searched, using key words, epidemiology and determinants of cholera infection in Pakistan during 1995 - 2010. Morbidity and mortality due to cholera infection during 1995 - 2010, without any language restriction. Out of 27 articles published between 1995 - 2010, 17 articles were included in the review. Vibrio cholerae O139 identified as a major cause of infection in older age group, while O1 biotype of cholera as a predominant cause of cholera among young individuals. Mainly reported determinants of cholera in Pakistan include poor sanitation and hygiene practices, increased population density in urban areas, leading to rapid and unplanned urbanization of the major cities and climate change due to increased environmental pollution in Pakistan are plausible factors for endemicity of cholera in Pakistan. Cholera reporting as a notifiable disease to the relevant departments and timely action can prevent the risk of outbreaks. There is a need to identify specific behavioral and environmental determinants responsible for outbreaks and epidemics of cholera in Pakistan which can help to design appropriate preventive and control interventions. PMID:25404447

  20. Hybrid microarray based on double biomolecular markers of DNA and carbohydrate for simultaneous genotypic and phenotypic detection of cholera toxin-producing Vibrio cholerae.

    PubMed

    Shin, Hwa Hui; Seo, Jeong Hyun; Kim, Chang Sup; Hwang, Byeong Hee; Cha, Hyung Joon

    2016-05-15

    Life-threatening diarrheal cholera is usually caused by water or food contaminated with cholera toxin-producing Vibrio cholerae. For the prevention and surveillance of cholera, it is crucial to rapidly and precisely detect and identify the etiological causes, such as V. cholerae and/or its toxin. In the present work, we propose the use of a hybrid double biomolecular marker (DBM) microarray containing 16S rRNA-based DNA capture probe to genotypically identify V. cholerae and GM1 pentasaccharide capture probe to phenotypically detect cholera toxin. We employed a simple sample preparation method to directly obtain genomic DNA and secreted cholera toxin as target materials from bacterial cells. By utilizing the constructed DBM microarray and prepared samples, V. cholerae and cholera toxin were detected successfully, selectively, and simultaneously; the DBM microarray was able to analyze the pathogenicity of the identified V. cholerae regardless of whether the bacteria produces toxin. Therefore, our proposed DBM microarray is a new effective platform for identifying bacteria and analyzing bacterial pathogenicity simultaneously. PMID:26735874

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

    PubMed Central

    2016-01-01

    ABSTRACT Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. PMID:27143391

  2. Numerical taxonomy of Vibrio cholerae and related species isolated from areas that are endemic and nonendemic for cholera.

    PubMed Central

    McNicol, L A; De, S P; Kaper, J B; West, P A; Colwell, R R

    1983-01-01

    A total of 165 strains of vibrios isolated from clinical and environmental sources in the United States, India, and Bangladesh, 11 reference cultures, and 4 duplicated cultures were compared in a numerical taxonomic study using 83 unit characters. Similarity between strains was computed by using the simple matching coefficient and the Jaccard coefficient. Strains were clustered by unweighted average linkage and single linkage algorithms. All methods gave similar cluster compositions. The estimated probability of error in the study was obtained from a comparison of the results of duplicated strains and was within acceptable limits. A total of 174 of the 180 organisms studied were divided into eight major clusters. Two clusters were identified as Vibrio cholerae, one as Vibrio mimicus, one as Vibrio parahaemolyticus, three as Vibrio species, and one as Aeromonas hydrophila. The V. mimicus cluster could be further divided into two subclusters, and the major V. cholerae group could be split into seven minor subclusters. Phenotypic traits routinely used to identify clinical isolates of V. cholerae can be used to identify environmental V. cholerae isolates. No distinction was found between strains of V. cholerae isolated from regions endemic for cholera and strains from nonendemic regions. PMID:6874901

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

    PubMed

    Boucher, Yan

    2016-01-01

    Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. PMID:27143391

  4. Construction and characterization of recombinant Vibrio cholerae strains producing inactive cholera toxin analogs.

    PubMed

    Häse, C C; Thai, L S; Boesman-Finkelstein, M; Mar, V L; Burnette, W N; Kaslow, H R; Stevens, L A; Moss, J; Finkelstein, R A

    1994-08-01

    The catalytic A subunit of cholera toxin (CT-A) is capable of ADP-ribosylating the guanine nucleotide-binding protein, which regulates cell adenylyl cyclase, leading to the life-threatening diarrhea of cholera. Amino acids involved in the enzymatic activity of CT-A have previously been identified. By means of site-directed mutagenesis, an analog of the CT-A subunit gene was created with codon substitutions for both Arg-7 and Glu-112, each of which has been shown to produce subunits lacking ADP-ribosyltransferase activity. The mutated gene fragment was exchanged for the wild-type copy in the previously cloned ctxAB operon from El Tor biotype, Ogawa serotype Vibrio cholerae strain 3083, which produces CT-2. Further, the zonula occludens toxin gene, zot, was inactivated by an insertional mutation to create the new plasmid construct pCT-2*. Additionally, a DNA fragment encoding the B subunit of CT-1 (CT produced by classical biotype, Inaba serotype V. cholerae strain 569B) was exchanged for the homologous part in pCT-2*, resulting in the creation of pCT-1*. These plasmid constructs were introduced into the CT-negative V. cholerae mutant strain JBK70 (E1 Tor biotype, Inaba serotype); CT-A-B+ derivatives CVD101 and CVD103 of classical biotype Ogawa and Inaba serotype strains 395 and 569B, respectively; El Tor biotype Inaba and Ogawa serotype strains C6706 and C7258, respectively, recently isolated in Peru; and O139 (synonym Bengal) strain SG25-1 from the current epidemic in India. Recombinant toxins (CT-1* and CT-2*), partially purified from culture supernatants of transformed JBK70, were shown to be inactive on mouse Y1 adrenal tumor cells and in an in vitro ADP-ribosyltransferase assay. CT-1* and CT-2* reacted with polyclonal and monoclonal antibodies against both A and B subunits of CT. The toxin analogs reacted with antibodies against CT-A and CT-B on cellulose acetate strips and in a GM1 enzyme-linked immunosorbent assay; they reacted appropriately with B

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

    PubMed Central

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

    2015-01-01

    Objective We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera. Methods To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility. Results Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (P<0.001 for both comparisons). Multiple-dose treatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains. Conclusions Single-dose ciprofloxacin

  6. Purification and characterization of the soluble hemagglutinin (cholera lectin)( produced by Vibrio cholerae.

    PubMed Central

    Finkelstein, R A; Hanne, L F

    1982-01-01

    The soluble hemagglutinin (HA) (cholera lectin) produced by Vibrio cholerae strain CA401 was purified to apparent homogeneity by a sequence of ammonium sulfate fractionation, gel filtration, and preparative isoelectric focusing. Soluble HA activity was found to focus at three different pIs, 6.3, 5.3, and 4.7. Each of the factors migrated as a large-molecular-weight protein in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under normal conditions, and each, upon heating in sodium dodecyl sulfate was found to dissociate into 32,000-molecular-weight subunits. Treating the samples with a reducing agent did not affect their mobility. Each gave a reaction of immunological identity with antiserum prepared against the others. Thus, there are apparently three distinct pH isotypes of soluble HA which exist as noncovalently associated polymers of 32,000-molecular-weight subunits. Electron microscopy of purified preparations revealed long filamentous polymers. The molecule does not stain as a glycoprotein; it is hydrophobic; it is inactivated during incubation at 25, 37, or 60 degrees C; and it has significant protease activity. The protease activity likewise focused at pH values of 6.3 and 5.3 to 4.7, and it was inhibited by antiserum against the HA. However, whereas the HA is active at 4 degrees C, the protease is not. The soluble HA is, therefore, a bifunctional molecule capable of mediating hemagglutination and proteolysis. Its amino acid composition is reported. Fab fragments of antibody against the purified HA inhibited attachment of heterologous serotype-biotype V. cholerae to infant rabbit small bowel. Images FIG. 2 FIG. 3 FIG. 6 FIG. 7 FIG. 8 PMID:7047394

  7. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned...

  8. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned...

  10. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  11. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned...

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

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-09-01

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

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

    PubMed Central

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

    2011-01-01

    We conducted a case–control study to investigate factors associated with epidemic cholera. Water treatment and handwashing may have been protective, highlighting the need for personal hygiene for cholera prevention in contaminated urban environments. We also found a diverse diet, a possible proxy for improved nutrition, was protective against cholera. PMID:22099120

  14. New qnr Gene Cassettes Associated with Superintegron Repeats in Vibrio cholerae O1

    PubMed Central

    dos Santos Freitas, Fernanda; Vieira, Verônica V.; Vicente, Ana C.P.

    2008-01-01

    A novel qnr determinant emerged in ciprofloxacin-resistant Vibrio cholerae O1 from the Amazon region of Brazil. This qnrVC1 was in a typical class 1 integron. Its attC showed 89% identity with V. parahaemolyticus superintegron repeats. Analysis showed V. cholerae O1 carrying qnrVC2 associated with a V. cholerae superintegron repeat. PMID:18598639

  15. Viable but nonculturable Vibrio cholerae O1 in biofilms in the aquatic environment and their role in cholera transmission

    PubMed Central

    Alam, Munirul; Sultana, Marzia; Nair, G. Balakrish; Siddique, A. K.; Hasan, Nur A.; Sack, R. Bradley; Sack, David A.; Ahmed, K. U.; Sadique, A.; Watanabe, H.; Grim, Christopher J.; Huq, A.; Colwell, Rita R.

    2007-01-01

    Vibrio cholerae persists in aquatic environments predominantly in a nonculturable state. In this study coccoid, nonculturable V. cholerae O1 in biofilms maintained for 495 days in Mathbaria, Bangladesh, pond water became culturable upon animal passage. Culturability, biofilm formation, and the wbe, ctxA, and rstR2 genes were monitored by culture, direct fluorescent antibody (DFA), and multiplex PCR. DFA counts were not possible after formation of biofilm. Furthermore, wbe, but not ctxA, were amplifiable, even after incubation for 54 and 68 days at room temperature (≈25°C) and 4°C, respectively, when no growth was detectable. Slower biofilm formation and extended culturability were observed for cultures incubated at 4°C, compared with ≈25°C, suggesting biofilm production to be temperature dependent and linked to loss of culturability. Small colonies appearing after incubation in microcosms for 54 and 68 days at 25°C and 4°C, respectively, were wbe positive and ctxA and rstR2 negative, indicating loss of bacteriophage CTXΦ. The coccoid V. cholerae O1 observed as free cells in microcosms incubated for 495 days could not be cultured, but biofilms in the same microcosms yielded culturable cells. It is concluded that biofilms can act as a reservoir for V. cholerae O1 between epidemics because of its long-term viability in biofilms. In contrast to biofilms produced in Mathbaria pond water, V. cholerae O1 in biofilms present in cholera stools and incubated under identical conditions as the Mathbaria pond water biofilms could not be cultured after 2 months, indicating that those V. cholerae cells freshly discharged into the environment are significantly less robust than cells adapted to environmental conditions. PMID:17968017

  16. Evaluation in Mice of a Conjugate Vaccine for Cholera Made from Vibrio cholerae O1 (Ogawa) O-Specific Polysaccharide

    PubMed Central

    Kalsy, Anuj; Yu, Y.; Freeman, Y. Wu; Sultana, Tania; Rashu, Md. Rasheduzzaman; Desai, Ishaan; Eckhoff, Grace; Leung, Daniel T.; Charles, Richelle C.; LaRocque, Regina C.; Harris, Jason B.; Clements, John D.; Calderwood, Stephen B.; Qadri, Firdausi; Vann, W. F.; Kováč, Pavol; Ryan, Edward T.

    2014-01-01

    Background Protective immunity against cholera is serogroup specific. Serogroup specificity in Vibrio cholerae is determined by the O-specific polysaccharide (OSP) of lipopolysaccharide (LPS). Generally, polysaccharides are poorly immunogenic, especially in young children. Methodology Here we report the evaluation in mice of a conjugate vaccine for cholera (OSP:TThc) made from V. cholerae O1 Ogawa O-Specific Polysaccharide–core (OSP) and recombinant tetanus toxoid heavy chain fragment (TThc). We immunized mice intramuscularly on days 0, 21, and 42 with OSP:TThc or OSP only, with or without dmLT, a non-toxigenic immunoadjuvant derived from heat labile toxin of Escherichia coli. Principal Findings We detected significant serum IgG antibody responses targeting OSP following a single immunization in mice receiving OSP:TThc with or without adjuvant. Anti-LPS IgG responses were detected following a second immunization in these cohorts. No anti-OSP or anti-LPS IgG responses were detected at any time in animals receiving un-conjugated OSP with or without immunoadjuvant, and in animals receiving immunoadjuvant alone. Responses were highest following immunization with adjuvant. Serum anti-OSP IgM responses were detected in mice receiving OSP:TThc with or without immunoadjuvant, and in mice receiving unconjugated OSP. Serum anti-LPS IgM and vibriocidal responses were detected in all vaccine cohorts except in mice receiving immunoadjuvant alone. No significant IgA anti-OSP or anti-LPS responses developed in any group. Administration of OSP:TThc and adjuvant also induced memory B cell responses targeting OSP and resulted in 95% protective efficacy in a mouse lethality cholera challenge model. Conclusion We describe a protectively immunogenic cholera conjugate in mice. Development of a cholera conjugate vaccine could assist in inducing long-term protective immunity, especially in young children who respond poorly to polysaccharide antigens. PMID:24516685

  17. Nonredundant Roles of Iron Acquisition Systems in Vibrio cholerae

    PubMed Central

    Peng, Eric D.; Wyckoff, Elizabeth E.; Mey, Alexandra R.; Fisher, Carolyn R.

    2015-01-01

    Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, thrives in both marine environments and the human host. To do so, it must encode the tools necessary to acquire essential nutrients, including iron, under these vastly different conditions. A number of V. cholerae iron acquisition systems have been identified; however, the precise role of each system is not fully understood. To test the roles of individual systems, we generated a series of mutants in which only one of the four systems that support iron acquisition on unsupplemented LB agar, Feo, Fbp, Vct, and Vib, remains functional. Analysis of these mutants under different growth conditions showed that these systems are not redundant. The strain carrying only the ferrous iron transporter Feo grew well at acidic, but not alkaline, pH, whereas the ferric iron transporter Fbp promoted better growth at alkaline than at acidic pH. A strain defective in all four systems (null mutant) had a severe growth defect under aerobic conditions but accumulated iron and grew as well as the wild type in the absence of oxygen, suggesting the presence of an additional, unidentified iron transporter in V. cholerae. In support of this, the null mutant was only moderately attenuated in an infant mouse model of infection. While the null mutant used heme as an iron source in vitro, we demonstrate that heme is not available to V. cholerae in the infant mouse intestine. PMID:26644383

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

    PubMed

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

    2016-04-01

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

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

    PubMed

    Topps, Maureen H

    2006-01-01

    The search for a safe, effective, well tolerated, low cost vaccine against the ancient cholera enemy has been ongoing since the 19th century and has been revitalized in the past two decades since the advent of recombinant technology. Large-scale field trials have readily demonstrated the tolerability and safety of oral cholera vaccine in various forms. Variable levels of protection have been shown and one challenge has been to demonstrate whether this is a cost effective treatment in differing environments including its use in endemic and epidemic areas as well as for travelers. A review of recent literature was undertaken to assess the effectiveness and uses of currently available oral cholera vaccine. While the evidence does not support the creation of formal guidelines, some clear recommendations can be made. There is undoubtedly the potential to reduce the burden of illness both in endemic and epidemic situations. For travelers, certain higher risk groups may benefit from protection against cholera. More significantly, the short term cross-protection afforded by whole cell, B subunit (WC BS) oral cholera vaccine formulations against enterotoxigenic E. coli, (ETEC), the commonest causative agent of traveler's diarrhoea, may prove to be the most important raison d'être. PMID:16887724

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  1. Isolation of isoelectrically pure cholera toxin for crystallization

    NASA Astrophysics Data System (ADS)

    Spangler, Brenda D.; Westbrook, Edwin M.

    1991-03-01

    We have determined that the failure of cholera toxin to crystallize well results from its isoelectric heterogeneity, which is probably due to a post-translational process such as deamidation of its B subunit. Every sample of cholera toxin we have examined from commercial or academic suppliers has been heterogeneous; heterogeneous cholera toxin does not crystallize satisfactorily. We have overcome this problem by using ion-exchange fast protein liquid chromatography (FPLC) to obtain an isoelectrically homogeneous species of cholera toxin. Homogeneous cholera toxin crystallizes readily, forming single, nonmosaic crystals suitable for X-ray diffraction studies. For this process, protein was applied to a MonoQ ion-exchange column, then eluted with an isocratic low salt buffer followed by a linear salt gradient (0-100 mM NaCl). Column fractions were analyzed on isoelectric focusing gels, and those fractions containing the desired homogeneous species were pooled and concentrated. Crystals formed within 24 to 48 h in a MOPS/PEG buffer, which made use of slow isoelectric precipitation to induce crystallization.

  2. Characterization of Undermethylated Sites in Vibrio cholerae

    PubMed Central

    Dalia, Ankur B.; Lazinski, David W.

    2013-01-01

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

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

    PubMed Central

    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

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

    PubMed Central

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

    2012-01-01

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

  5. Evaluation of a Rapid Test for the Diagnosis of Cholera in the Absence of a Gold Standard

    PubMed Central

    Page, Anne-Laure; Alberti, Kathryn P.; Mondonge, Vital; Rauzier, Jean; Quilici, Marie-Laure; Guerin, Philippe J.

    2012-01-01

    Background Early detection and confirmation of cholera outbreaks are crucial for rapid implementation of control measures. Because cholera frequently affects regions with limited laboratory resources, rapid diagnostic tests (RDT) designed for field conditions are important to enhance rapid response. Stool culture remains the “gold standard” for cholera diagnosis; however, its lack of sensitivity may lead to underestimation of test specificity. We evaluated the Crystal VC® immunochromatographic test (Span Diagnostics, India) for cholera diagnosis using a modified reference standard that combines culture-dependent and independent assays, or a Bayesian latent class model (LCM) analysis. Methodology/Principal Findings The study was conducted during a cholera epidemic in 2008, in Lubumbashi, Democratic Republic of Congo. Stools collected from 296 patients were used to perform the RDT on site and sent to Institut Pasteur, Paris, for bacterial culture. In comparison with culture as the gold standard, the RDT showed good sensitivity (92.2%; 95% CI: 86.8%–95.9%) but poor specificity when used by a trained laboratory technician (70.6%; 95% CI: 60.7%–79.2%) or by clinicians with no specific test training (60.4%, 95% CI: 50.2%–70.0%). The specificity of the test performed by the laboratory technician increased to 88.6% (95% CI: 78.7–94.9) when PCR was combined with culture results as the reference standard, and to 85.0% (95% CI: 70.4–99.2), when the Bayesian LCM analysis was used for performance evaluation. In both cases, the sensitivity remained high. Conclusion Using an improved reference standard or appropriate statistical methods for diagnostic test evaluations in the absence of a gold standard, we report better performance of the Crystal VC® RDT than previously published. Our results confirm that this test can be used for early outbreak detection or epidemiological surveillance, key components of efficient global cholera control. Our analysis also

  6. Genome-Wide Study of the Defective Sucrose Fermenter Strain of Vibrio cholerae from the Latin American Cholera Epidemic

    PubMed Central

    Garza, Daniel Rios; Thompson, Cristiane C.; Loureiro, Edvaldo Carlos Brito; Dutilh, Bas E.; Inada, Davi Toshio; Junior, Edivaldo Costa Sousa; Cardoso, Jedson Ferreira; Nunes, Márcio Roberto T.; de Lima, Clayton Pereira Silva; Silvestre, Rodrigo Vellasco Duarte; Nunes, Keley Nascimento Barbosa; Santos, Elisabeth C. O.; Edwards, Robert A.; Vicente, Ana Carolina P.; de Sá Morais, Lena Lillian Canto

    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 characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics. PMID:22662140

  7. Review of recent trends in cholera research and control

    PubMed Central

    Felsenfeld, O.

    1966-01-01

    Since 1961 cholera El Tor has been sweeping through the Far East, and this dissemination of the disease has stimulated research not only in the countries afflicted but also in Europe and the Americas. New laboratories and workers have entered the field and many fresh ideas and concepts have emerged. The time seemed ripe, therefore, to survey the most important papers published since 1959, when the literature on cholera was thoroughly reviewed by Pollitzer, for the benefit both of those engaged in research and of those concerned with public health practice. This review covers history and incidence, causative agents (including the ”classical”, ”El Tor” and ”incomplete” forms), pathophysiology, diagnosis, treatment, mode of spreading and control measures (with particular reference to public health education and the International Sanitary Regulations). An annex, intended for laboratory use, contains selected procedures for the isolation and identification of cholera vibrios. PMID:5328492

  8. [The characteristics of Vibrio cholerae isolated in Dagestan in 1994].

    PubMed

    Podosinnikova, L S; Mazrukho, B L; Lomov, Iu M; Khanum'ian, T A; Voronezhskaia, L G; Kudriakova, T A; Makedonova, L D; Mironova, A V

    1995-01-01

    A high degree of resistance to cholera diagnostic phages and carriership of prophages characteristic of V. cholerae eltor strains vct+ were shown to be the specific features V. cholerae isolated in Daghestan during the period of June-October 1994. Among the strains under study, isolated respectively in 12 and 18 out of 19 regions of Daghestan, a high proportion was found to have resistance to tetracycline (65%) and chloramphenicol (28.6%). Moreover, some strains were found to be resistant to furagin and erythromycin. Out of 242 strains resistant to antibacterial preparations, 163 strains were found to have multiple resistance. Gentamicin, cipropfloxacin and doxicycline were shown to have high in vitro activity with respect to the strains under study. PMID:7771152

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

    PubMed Central

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

    2011-01-01

    Phytoplankton abundance is inversely related to sea surface temperature (SST). However, a positive relationship is observed between SST and phytoplankton abundance in coastal waters of Bay of Bengal. This has led to an assertion that in a warming climate, rise in SST may increase phytoplankton blooms and, therefore, cholera outbreaks. Here, we explain why a positive SST-phytoplankton relationship exists in the Bay of Bengal and the implications of such a relationship on cholera dynamics. We found clear evidence of two independent physical drivers for phytoplankton abundance. The first one is the widely accepted phytoplankton blooming produced by the upwelling of cold, nutrient-rich deep ocean waters. The second, which explains the Bay of Bengal findings, is coastal phytoplankton blooming during high river discharges with terrestrial nutrients. Causal mechanisms should be understood when associating SST with phytoplankton and subsequent cholera outbreaks in regions where freshwater discharge are a predominant mechanism for phytoplankton production. PMID:21813852

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

    PubMed

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

    2016-03-01

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

  11. Mortality Rates during Cholera Epidemic, Haiti, 2010–2011

    PubMed Central

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

    2016-01-01

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

  12. [The first case of Vibrio cholerae 0139 in Denmark].

    PubMed

    Dalsgaard, A; Nielsen, G L; Echeverria, P; Larsen, J L; Schønheyder, H C

    1996-09-01

    We report the first case of V. cholerae O139 in Denmark. In 1994, a 61-year-old Vietnamese woman was admitted to Aalborg Hospital, Denmark due to severe diarrhoea. The diagnosis was confirmed by biochemical characterization and agglutination in O139 antiserum of a strain isolated from a stool specimen. The woman had stayed in Denmark after family reunion for nine months and had not travelled outside the country. She had not eaten any foods imported from Southeast Asia. The V. cholerae O139 isolate had similar antibiotic susceptibility pattern and contained genes encoding a virulence gene cassette previously identified in O139 isolates from Southeast Asia. Ribotyping showed a banding pattern similar to patterns exhibited by O139 isolates from Bangladesh, India and Thailand. However, the exact mode of transmission of this first Danish case of V. cholerae O139 infection was not determined. PMID:8848850

  13. Flow cytofluorometric monitoring of leukocyte apoptosis in experimental cholera

    NASA Astrophysics Data System (ADS)

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

    2003-10-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. PMID:26048558

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

    PubMed Central

    Emch, Michael; Feldacker, Caryl; Islam, M Sirajul; Ali, Mohammad

    2008-01-01

    Background The seasonality of cholera is described in various study areas throughout the world. However, no study examines how temporal cycles of the disease vary around the world or reviews its hypothesized causes. This paper reviews the literature on the seasonality of cholera and describes its temporal cycles by compiling and analyzing 32 years of global cholera data. This paper also provides a detailed literature review on regional patterns and environmental and climatic drivers of cholera patterns. Data, Methods, and Results Cholera data are compiled from 1974 to 2005 from the World Health Organization Weekly Epidemiological Reports, a database that includes all reported cholera cases in 140 countries. The data are analyzed to measure whether season, latitude, and their interaction are significantly associated with the country-level number of outbreaks in each of the 12 preceding months using separate negative binomial regression models for northern, southern, and combined hemispheres. Likelihood ratios tests are used to determine the model of best fit. The results suggest that cholera outbreaks demonstrate seasonal patterns in higher absolute latitudes, but closer to the equator, cholera outbreaks do not follow a clear seasonal pattern. Conclusion The findings suggest that environmental and climatic factors partially control the temporal variability of cholera. These results also indirectly contribute to the growing debate about the effects of climate change and global warming. As climate change threatens to increase global temperature, resulting rises in sea levels and temperatures may influence the temporal fluctuations of cholera, potentially increasing the frequency and duration of cholera outbreaks. PMID:18570659

  17. Familial Aggregation of Vibrio cholerae-associated Infection in Matlab, Bangladesh

    PubMed Central

    Duggal, Priya; Harris, Jason B.; Saha, Sajal Kumar; Streatfield, Peter Kim; Ryan, Edward T.; Calderwood, Stephen B.; Qadri, Firdausi; Yunus, Mohammad; LaRocque, Regina C.

    2009-01-01

    Vibrio cholerae is a major cause of diarrhoeal illness in endemic regions, such as Bangladesh. Understanding the factors that determine an individual's susceptibility to infection due to V. cholerae may lead to improved prevention and control strategies. Increasing evidence suggests that human genetic factors affect the severity of V. cholerae-associated infection. This study, therefore, sought to characterize the heritable component of susceptibility to infection due to V. cholerae using the Matlab Health and Demographic Surveillance System database of the International Centre for Diarrhoeal Disease Research, Bangladesh. In total, 144 pedigrees that included a cholera patient and 341 pedigrees without a cholera patient were evaluated during 1 January–31 December 1992. The odds of the sibling of a patient being admitted with cholera were 7.67 times the odds of the sibling of an unaffected individual being admitted with cholera [95% confidence interval (CI) 2.40–24.5, p<0.001], after adjustment for gender, age, socioeconomic status, and hygiene practices. Although exposure to environmental reservoirs is essential in the epidemiology of cholera, household-specific factors, such as familial relatedness to an index case, may also be important determinants of risk of cholera. Further analysis of human genetic factors that contribute to susceptibility to cholera may be productive. PMID:20099756

  18. Field evaluation of environmental sanitation measures against cholera*

    PubMed Central

    Azurin, J. C.; Alvero, M.

    1974-01-01

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

  19. Field evaluation of environmental sanitation measures against cholera.

    PubMed

    Azurin, J C; Alvero, M

    1974-01-01

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

  20. Avian cholera in Southern Great Petrel (Macronectes giganteus) from Antarctica

    USGS Publications Warehouse

    Leotta, G.A.; Rivas, M.; Chinen, I.; Vigo, G.B.; Moredo, F.A.; Coria, N.; Wolcott, M.J.

    2003-01-01

    A southern giant petrel (Macronectes giganteus) was found dead at Potter Peninsula, King George Island, South Shetland, Antarctica. The adult male was discovered approximately 48 hr after death. Macroscopic and microscopic lesions were compatible with avian cholera and the bacterium Pasteurella multocida subsp. gallicida, serotype A1 was isolated from lung, heart, liver, pericardial sac, and air sacs. In addition, Escherichia coli was isolated from pericardial sac and air sacs. This is the first known report of avian cholera in a southern giant petrel in Antarctica.

  1. Whole-genome sequence comparisons reveal the evolution of Vibrio cholerae O1.

    PubMed

    Kim, Eun Jin; Lee, Chan Hee; Nair, G Balakrish; Kim, Dong Wook

    2015-08-01

    The analysis of the whole-genome sequences of Vibrio cholerae strains from previous and current cholera pandemics has demonstrated that genomic changes and alterations in phage CTX (particularly in the gene encoding the B subunit of cholera toxin) were major features in the evolution of V. cholerae. Recent studies have revealed the genetic mechanisms in these bacteria by which new variants of V. cholerae are generated from type-specific strains; these mechanisms suggest that certain strains are selected by environmental or human factors over time. By understanding the mechanisms and driving forces of historical and current changes in the V. cholerae population, it would be possible to predict the direction of such changes and the evolution of new variants; this has implications for the battle against cholera. PMID:25913612

  2. An intracellular replication niche for Vibrio cholerae in the amoeba Acanthamoeba castellanii.

    PubMed

    Van der Henst, Charles; Scrignari, Tiziana; Maclachlan, Catherine; Blokesch, Melanie

    2016-04-01

    Vibrio cholerae is a human pathogen and the causative agent of cholera. The persistence of this bacterium in aquatic environments is a key epidemiological concern, as cholera is transmitted through contaminated water. Predatory protists, such as amoebae, are major regulators of bacterial populations in such environments. Therefore, we investigated the interaction between V. cholerae and the amoeba Acanthamoeba castellanii at the single-cell level. We observed that V. cholerae can resist intracellular killing. The non-digested bacteria were either released or, alternatively, established a replication niche within the contractile vacuole of A. castellanii. V. cholerae was maintained within this compartment even upon encystment. The pathogen ultimately returned to its aquatic habitat through lysis of A. castellanii, a process that was dependent on the production of extracellular polysaccharide by the pathogen. This study reinforces the concept that V. cholerae is a facultative intracellular bacterium and describes a new host-pathogen interaction. PMID:26394005

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

    PubMed Central

    Goel, A. K.; Jiang, S. C.

    2011-01-01

    The outbreak of waterborne disease cholera has been associated with rainfall and flooding events by contamination of potable water with environmental Vibrio cholerae. The continuation of the epidemic in a region, however, is often due to secondary transmission of the initial outbreak strain through human waste. This paper reports, on the contrary, a rapid shift of genotype from one V. cholerae strain to another one in an epidemic region. V. cholerae isolated from patients during 2005 cholera epidemic in Chennai, India were characterized using PCR identification of toxin genes, antibiogram, and genomic fingerprinting analysis. The results showed that in spite of the similarity of toxin genes and antibiogram, the Vibrio isolates grouped into two different clusters based on the ERIC-PCR fingerprinting. Each cluster corresponded to a distinct peak of cholera outbreak, which occurred after separate heavy rainfall. The results suggest that the rainfall event can bring various genotypes of V. cholerae strains causing multiple outbreaks. PMID:22194751

  4. Growth of Vibrio cholerae O1 Ogawa Eltor in freshwater.

    PubMed

    Vital, Marius; Füchslin, Hans Peter; Hammes, Frederik; Egli, Thomas

    2007-07-01

    Growth of Vibrio cholerae O1 Ogawa Eltor was studied with a growth assay in which autoclaved and filtered (0.22 microm) freshwater was inoculated at low cell density (5 x 10(3) cells ml(-1)) and proliferation was followed with flow cytometry. Against the common view, V. cholerae was able to grow extensively in different kinds of freshwater. The bacterium multiplied in river water, lake water and effluent of a wastewater treatment plant up to a cell density of 1.55 x 10(6) cells ml(-1). In these samples, apparent assimilable organic carbon (AOC(app)) concentrations ranged from 52 up to 800 microg l(-1) and the results demonstrate a positive trend between the AOC(app) concentration and final cell concentration, suggesting that AOC was a key parameter governing growth of V. cholerae. No growth was observed in waters (tap and bottled drinking water) containing less than approximately 60 microg AOC(app) l(-1). When pure cultures of V. cholerae were grown on identical lake water at different temperatures (20, 25 and 30 degrees C) the maximum specific growth rates (micromax) achieved were 0.22 h(-1), 0.32 h(-1) and 0.45 h(-1), respectively. In addition, growth was characterized in lake water samples amended with different concentrations of NaCl. The highest micromax of V. cholerae was recorded at moderate salinity levels (5 g NaCl l(-1), micromax=0.84 h(-1)), whereas at 30 g NaCl l(-1) (micromax=0.30 h(-1)) or 0 g NaCl l(-1) (micromax)=0.40 h(-1)) specific growth rates were significantly reduced. In the water tested here, micro(max) of V. cholerae was always around 50 % of that exhibited by a freshwater community of indigenous bacteria enriched from the water sampling site. Direct batch competition experiments between V. cholerae and the lake water bacterial community were performed at different temperatures in which V. cholerae was enumerated in the total community using fluorescent-surface antibodies. In all cases V. cholerae was able to grow and constituted around 10

  5. Climate and socioeconomic influences on interannual variability of cholera in Nigeria.

    PubMed

    Leckebusch, Gregor C; Abdussalam, Auwal F

    2015-07-01

    Cholera is one of the most important climate sensitive diseases in Nigeria that pose a threat to public health because of its fatality and endemic nature. This study aims to investigate the influences of meteorological and socioeconomic factors on the spatiotemporal variability of cholera morbidity and mortality in Nigeria. Stepwise multiple regression and generalised additive models were fitted for individual states as well as for three groups of the states based on annual precipitation. Different meteorological variables were analysed, taking into account socioeconomic factors that are potentially enhancing vulnerability (e.g. absolute poverty, adult literacy, access to pipe borne water). Results quantify the influence of both climate and socioeconomic variables in explaining the spatial and temporal variability of the disease incidence and mortality. Regional importance of different factors is revealed, which will allow further insight into the disease dynamics. Additionally, cross validated models suggest a strong possibility of disease prediction, which will help authorities to put effective control measures in place which depend on prevention, and or efficient response. PMID:25997026

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

    PubMed

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

    2016-09-01

    Over the last decade, isolation and purification of monoclonal antibodies, for diagnostic analysis, have been carried out using the hybridoma expression system. The present study describes a novel example of a detection system using hybridoma cells containing antibody against O1 antigen directly for V. cholerae diagnosis, which is a major health problem in many parts of the world, especially in developing countries. This method has advantages such as simplicity, ease of process, and it does not require manipulation of hybridoma cell. For this approach, an efficient amount of fluorescence calcium indicator, fura 2-AM, was utilized, which emitted light when the intracellular calcium concentration increased as result of antigen binding to specific antibody. More reliable results are obtained via this method and it is considerably faster than other methods, which has the response time of less than 45 s for detection of V. Cholerae O1. Also, the limit of detection was computed to be 50 CFU/mL (<13 CFU per assay). In addition, no significant responses were observed in the presence of other bacteria with specific hybridoma or other cell lines exposed to V. cholerae O1. Furthermore, this method was successfully applied to V. cholerae O1 detection in spiked environmental samples, including water and stool samples without any pretreatment. All results reveal that hybridoma cells can provide a valuable, simple, and ready to use tool for rapid detection of other pathogenic bacteria, toxins, and analytes. PMID:27438715

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

    PubMed

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

    1994-01-01

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

  8. Extraction from prawn shells of substances cryoprotective for Vibrio cholerae.

    PubMed Central

    Shimodori, S; Moriya, T; Kohashi, O; Faming, D; Amako, K

    1989-01-01

    Substances cryoprotective for Vibrio cholerae were detected from prawn shells immersed in phosphate-buffered saline. This cryoprotective activity was heat resistant and sensitive to treatment with trypsin. For the exhibition of its full activity, the presence of Mg ion was indispensable. The cryoprotective activity of this substance was more active than that of other known cryoprotectants, like glycerol or serum. PMID:2604409

  9. Cholera Toxin and Cell Growth: Role of Membrane Gangliosides

    PubMed Central

    Hollenberg, Morley D.; Fishman, Peter H.; Bennett, Vann; Cuatrecasas, Pedro

    1974-01-01

    The binding of cholera toxin to three transformed mouse cell lines derived from the same parent strain, and the effects of the toxin on DNA synthesis and adenylate cyclase activity, vary in parallel with the ganglioside composition of the cells. TAL/N cells of early passage, which contain large quantities of gangliosides GM3, GM2, GM1, and GDla, as well as the glycosyltransferases necessary for the synthesis of these gangliosides, bind the most cholera toxin and are the most sensitive to its action. TAL/N cells of later passage, which lack chemically detectable GM1 and GDla and which have no UDP-Gal:GM2 galactosyltransferase activity, are intermediate in binding and response to the toxin. SVS AL/N cells, which lack GM2 in addition to GM1 and GDla and which have little detectable UDP-GalNAc:GM3N-acetylgalactosaminyltransferase activity, bind the least amount of toxin. The SVS AL/N cells are the least responsive to inhibition of DNA synthesis and stimulation of adenylate cyclase activity by cholera toxin. Gangliosides (especially GM1), which appear to be the natural membrane receptors for cholera toxin, may normally have important roles in the regulation of cell growth and cAMP-mediated responses. PMID:4530298

  10. Cholera in Bahrain: epidemiological characteristics of an outbreak*

    PubMed Central

    Gunn, Robert A.; Kimball, Ann M.; Mathew, P. P.; Dutta, S. R.; Rifaat, A. H. M.

    1981-01-01

    In the period 10 August 1978-23 January 1979, 913 culture-confirmed cases of cholera caused by Vibrio cholerae, biotype El Tor, serotype Ogawa, occurred in Bahrain. After discovery of the initial cases, others occurred sporadically, and the incidence reached a peak of 25-35 cases per day during the seventh week of the outbreak (16-22 September). The overall attack rate (27 per 10 000) was low and the outbreak subsided without mass immunization campaigns or rigorous border control of persons and imports. Investigation of 746 culture-confirmed cases that occurred in the period 10 August—13 October 1978, showed that cases occurred throughout most areas of the country and mainly affected infants, young children, and adult working-age males. Symptoms were very mild; fewer than 20% of patients required specific rehydration therapy. The highest attack rate (84 per 10 000) occurred in infants less than 1 year of age. No common vehicle or mode of transmission was identified. A matched-pair study of 35 cases and controls showed that adult cases were more likely than controls to have consumed food or beverage outside of the home before becoming ill. V. cholerae was isolated from stored drinking water in the houses of 8 cases but not from numerous samples of food and tap-water. It was presumed that cholera transmission occurred through a complex interaction of mild and asymptomatically infected persons with food, water, and the environment. PMID:6973417

  11. Isolation of Vibrio cholerae serotype Ogawa from a Florida estuary.

    PubMed

    Motes, M L; Zywno, S R; DePaola, A; Becker, R E; Presnell, M W

    1983-01-01

    Vibrio cholerae serotype Ogawa was recently isolated from the estuarine waters of Apalachicola Bay, Fla., in areas that are subject to consistent fecal contamination and in areas that are remote from any apparent source of contamination. The significance of these organisms in the environment has not been determined. PMID:6824323

  12. Cholera toxin effects on body temperature changes induced by morphine.

    PubMed

    Basilico, L; Parenti, M; Fumagalli, A; Parolaro, D; Giagnoni, G

    1997-03-01

    The present study evaluates the influence of cholera toxin and its B-subunit on thermic responses to morphine in the rats. The holotoxin (1 microg/rat) and the B-subunit (5 microg) were administered ICV and three days later rats were challenged ICV with morphine and tested for changes of body temperature. Cholera toxin, but not its B-subunit, modified the time course of the hyperthermic response induced by a low dose of morphine (2.5 microg), converted the hypothermia due to a higher dose of morphine (18 microg) to a consistent hyperthermia and only partially reduced the greater hypothermia induced by 36 microg of morphine. Cholera toxin-induced modifications of thermic responses to morphine were paralleled with a decreased Gs(alpha) immunoreactivity and a reduced ability for the toxin to catalyse the "in vitro" ADP-ribosylation of Gs(alpha) in hypothalamic membranes. In contrast, at the same time when morphine-induced effects on body temperature were assessed, no changes in pertussis toxin-mediated ADP-ribosylation of Gi(alpha)/Go(alpha), or basal adenylate cyclase activity, or binding of mu-opioid receptor selective ligand [3H]-DAMGO were observed in hypothalamic areas from rats treated with cholera toxin. These findings suggest that adaptative events secondary to prolonged activation of Gs(alpha) play a role in the modifications of thermic responses to morphine induced by CTX. PMID:9077589

  13. Invariant recognition of polychromatic images of Vibrio cholerae 01

    NASA Astrophysics Data System (ADS)

    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.

  14. Rapid and Scalable Plant-based Production of a Cholera Toxin B Subunit Variant to Aid in Mass Vaccination against Cholera Outbreaks

    PubMed Central

    Bennett, Lauren J.; Baldauf, Keegan J.; Kajiura, Hiroyuki; Fujiyama, Kazuhito; Matoba, Nobuyuki

    2013-01-01

    Introduction Cholera toxin B subunit (CTB) is a component of an internationally licensed oral cholera vaccine. The protein induces neutralizing antibodies against the holotoxin, the virulence factor responsible for severe diarrhea. A field clinical trial has suggested that the addition of CTB to killed whole-cell bacteria provides superior short-term protection to whole-cell-only vaccines; however, challenges in CTB biomanufacturing (i.e., cost and scale) hamper its implementation to mass vaccination in developing countries. To provide a potential solution to this issue, we developed a rapid, robust, and scalable CTB production system in plants. Methodology/Principal Findings In a preliminary study of expressing original CTB in transgenic Nicotiana benthamiana, the protein was N-glycosylated with plant-specific glycans. Thus, an aglycosylated CTB variant (pCTB) was created and overexpressed via a plant virus vector. Upon additional transgene engineering for retention in the endoplasmic reticulum and optimization of a secretory signal, the yield of pCTB was dramatically improved, reaching >1 g per kg of fresh leaf material. The protein was efficiently purified by simple two-step chromatography. The GM1-ganglioside binding capacity and conformational stability of pCTB were virtually identical to the bacteria-derived original B subunit, as demonstrated in competitive enzyme-linked immunosorbent assay, surface plasmon resonance, and fluorescence-based thermal shift assay. Mammalian cell surface-binding was corroborated by immunofluorescence and flow cytometry. pCTB exhibited strong oral immunogenicity in mice, inducing significant levels of CTB-specific intestinal antibodies that persisted over 6 months. Moreover, these antibodies effectively neutralized the cholera holotoxin in vitro. Conclusions/Significance Taken together, these results demonstrated that pCTB has robust producibility in Nicotiana plants and retains most, if not all, of major biological activities of

  15. The discovery of cholera - like enterotoxins produced by Escherichia coli causing secretory diarrhoea in humans

    PubMed Central

    Sack, R. Bradley

    2011-01-01

    Non-vibrio cholera has been recognized as a clinical entity for as long as cholera was known to be caused by Vibrio cholerae. Until 1968, the aetiologic agent of this syndrome was not known. Following a series of studies in patients with non-vibrio cholera it was found that these patients had large concentrations of Escherichia coli in the small bowel and stools which produced cholera toxin-like enterotoxins, and had fluid and electrolyte transport abnormalities in the small bowel similar to patients with documented cholera. Furthermore, these patients developed antibodies to the cholera-like enterotoxin. Later studies showed that these strains, when fed to volunteers produced a cholera-like disease and that two enterotoxins were found to be produced by these organisms: a heat-labile enterotoxin (LT) which is nearly identical to cholera toxin, and a heat-stable enterotoxin (ST), a small molecular weight polypeptide. E. coli that produced one or both of these enterotoxins were designated enterotoxigenic E. coli (ETEC). ETEC are now known not only to cause a severe cholera-like illness, but to be the most common bacterial cause of acute diarrhoea in children in the developing world, and to be the most common cause of travellers’ diarrhoea in persons who visit the developing world. PMID:21415491

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

    PubMed

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

    2012-09-01

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

  17. An optimal cost effectiveness study on Zimbabwe cholera seasonal data from 2008-2011.

    PubMed

    Sardar, Tridip; Mukhopadhyay, Soumalya; Bhowmick, Amiya Ranjan; Chattopadhyay, Joydev

    2013-01-01

    Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008-09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008-09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to study such recurrent occurrences and fitted the model to cumulative cholera cases and deaths for different provinces of Zimbabwe from the beginning of cholera outbreak in 2008-09 to June 2011. Daily and weekly reported cholera incidence data were collected from Zimbabwe epidemiological bulletin, Zimbabwe Daily cholera updates and Office for the Coordination of Humanitarian Affairs Zimbabwe (OCHA, Zimbabwe). For each province, the basic reproduction number ([Formula: see text]) in periodic environment is estimated. To the best of our knowledge, this is probably a pioneering attempt to estimate [Formula: see text] in periodic environment using real-life data set of cholera epidemic for Zimbabwe. Our estimates of [Formula: see text] agree with the previous estimate for some provinces but differ significantly for Bulawayo, Mashonaland West, Manicaland, Matabeleland South and Matabeleland North. Seasonal trend in cholera incidence is observed in Harare, Mashonaland West, Mashonaland East, Manicaland and Matabeleland South. Our result suggests that, slow transmission is a dominating factor for cholera transmission in most of these provinces. Our model projects [Formula: see text] cholera cases and [Formula: see text] cholera deaths during the end of the epidemic in 2008-09 to January 1, 2012. We also determine an optimal cost-effective control strategy among the four government undertaken interventions namely promoting hand-hygiene & clean water distribution, vaccination, treatment

  18. Insights into Vibrio cholerae Intestinal Colonization from Monitoring Fluorescently Labeled Bacteria

    PubMed Central

    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 this distribution. Here, using confocal and intravital two-photon microscopy to monitor the localization of fluorescently tagged V. cholerae strains, we uncovered unexpected and previously unrecognized features of V. cholerae intestinal colonization. Direct visualization of the pathogen within the intestine revealed that the majority of V. cholerae microcolonies attached to the intestinal epithelium arise from single cells, and that there are notable regiospecific aspects to V. cholerae localization and factors required for colonization. In the proximal SI, V. cholerae reside exclusively within the developing intestinal crypts, but they are not restricted to the crypts in the more distal SI. Unexpectedly, V. cholerae motility proved to be a regiospecific colonization factor that is critical for colonization of the proximal, but not the distal, SI. Furthermore, neither motility nor chemotaxis were required for proper V. cholerae distribution along the villous axis or in crypts, suggesting that yet undefined processes enable the pathogen to find its niches outside the intestinal lumen. Finally, our observations suggest that host mucins are a key factor limiting V. cholerae intestinal colonization, particularly in the proximal SI where there appears to be a more abundant mucus layer. Collectively, our findings demonstrate the potent capacity of direct pathogen visualization during infection to deepen our understanding of host pathogen interactions. PMID:25275396

  19. Cholera in the time of civil war. Liberia.

    PubMed

    Barth, J

    1991-01-01

    170 years of strife in Liberia between freed slaves from the Americas (Americo-Liberians) and indigenous tribes erupted in 1980 when a member of the indigenous ethnic group the Khran overthrew and killed the president. Contrary to what he promised, an equitable distribution of goods and services did not occur, human rights abuses continued, and civil service jobs went to Khran members. Many Americo-Liberians left. The US government recognized his government in 1986. US government and corporate interest in Liberia included a Voice of American transmitter, a navigation station, and rubber plantations. A civil war followed. An African American teacher ran a cholera ward during the war at Island Hospital where staff was not used to treating the lower class. She also started an orphanage next to the hospital, initially, for the well children from the ward. She operated the ward because the physician had left and cholera treatment included double-dosing patients with chloramphenicol and tetracycline. Moreover, patients also received an anti-parasitic. Further, kwashiorkor was common in Liberia. Only soldiers received intravenous therapy, so cholera patients were not rehydrated. The teacher and 3 student nurses began administering oral rehydration fluids orally every 5 minutes and saved lives. Despite evidence that the patients indeed had cholera, the US embassy physician refused to admit it for a long time. Eventually, the embassy sent medicine stored for weeks to the ward. A long time after widespread diarrhea started, the British Broadcasting Corporation began a radio program about oral rehydration. Yet many people did not understand its message without seeing a demonstration of mixing oral rehydration salts. Moreover, many people treated diarrhea with a diuretic medication which only complicated it. Nevertheless, the teacher and her efforts stopped cholera. She also helped a woman set up a home for handicapped children who survived the war. PMID:12159259

  20. Funerals during the 1994 cholera epidemic in Guinea-Bissau, West Africa: the need for disinfection of bodies of persons dying of cholera.

    PubMed

    Gunnlaugsson, G; Einarsdóttir, J; Angulo, F J; Mentambanar, S A; Passa, A; Tauxe, R V

    1998-02-01

    The 1994 cholera epidemic in Guinea-Bissau resulted in 15,878 reported cases and 306 deaths. Early in the epidemic, although the health ministry mandated that the bodies of persons dying of cholera be disinfected, outbreaks occurred in several villages following funerals in the region of Biombo. To determine the influence of disinfection and funeral activities on cholera transmission, we analysed surveillance data and conducted a case-control study following a funeral. The attack rate during the week following funerals was higher in villages where bodies were not disinfected (risk ratio = 2.6, 95% confidence interval [CI] 1.9-3.8). Cholera was strongly associated with eating at a funeral with a non-disinfected corpse (odds ratio [OR] = 14.5, 95% CI 0.9-786) and with touching (i.e., transporting, washing) the body (OR = 36.2, 95% CI 2.6-1769). During cholera epidemics, in addition to other cholera prevention activities, health officials should inform community leaders about the risk of cholera transmission during funerals, meals should not be served at funerals, and bodies of persons dying of cholera should be disinfected. PMID:9528812

  1. Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

    PubMed Central

    Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

    2014-01-01

    As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

  2. Competence-induced type VI secretion might foster intestinal colonization by Vibrio cholerae: Intestinal interbacterial killing by competence-induced V. cholerae.

    PubMed

    Blokesch, Melanie

    2015-11-01

    The human pathogen Vibrio cholerae exhibits two distinct lifestyles: one in the aquatic environment where it often associates with chitinous surfaces and the other as the causative agent of the disease cholera. While much of the research on V. cholerae has focused on the host-pathogen interaction, knowledge about the environmental lifestyle of the pathogen remains limited. We recently showed that the polymer chitin, which is extremely abundant in aquatic environments, induces natural competence as a mode of horizontal gene transfer and that this competence regulon also includes the type VI secretion system (T6SS), a molecular killing device. Here, I discuss the putative consequences that chitin-induced T6SS activation could have on intestinal colonization and how the transmission route might influence disease outcome. Moreover, I propose that common infant animal models for cholera might not sufficiently take into account T6SS-mediated interbacterial warfare between V. cholerae and the intestinal microbiota. PMID:26445388

  3. The Vibrio cholerae type VI secretion system employs diverse effector modules for intraspecific competition

    PubMed Central

    Unterweger, Daniel; Miyata, Sarah T.; Bachmann, Verena; Brooks, Teresa M.; Mullins, Travis; Kostiuk, Benjamin; Provenzano, Daniele; Pukatzki, Stefan

    2014-01-01

    Vibrio cholerae is a Gram-negative bacterial pathogen that consists of over 200 serogroups with differing pathogenic potential. Only strains that express the virulence factors cholera toxin (CT) and toxin-coregulated pilus (TCP) are capable of pandemic spread of cholera diarrhoea. Regardless, all V. cholerae strains sequenced to date harbour genes for the type VI secretion system (T6SS) that translocates effectors into neighbouring eukaryotic and prokaryotic cells. Here we report that the effectors encoded within these conserved gene clusters differ widely among V. cholerae strains, and that immunity proteins encoded immediately downstream from the effector genes protect their host from neighbouring bacteria producing corresponding effectors. As a consequence, strains with matching effector-immunity gene sets can coexist, while strains with different sets compete against each other. Thus, the V. cholerae T6SS contributes to the competitive behaviour of this species. PMID:24686479

  4. Dynamics of Cholera Outbreaks in Great Lakes Region of Africa, 1978–2008

    PubMed Central

    Nkoko, Didier Bompangue; Giraudoux, Patrick; Plisnier, Pierre-Denis; Tinda, Annie Mutombo; Piarroux, Martine; Sudre, Bertrand; Horion, Stephanie; Tamfum, Jean-Jacques Muyembe; Ilunga, Benoît Kebela

    2011-01-01

    Cholera outbreaks have occurred in Burundi, Rwanda, Democratic Republic of Congo, Tanzania, Uganda, and Kenya almost every year since 1977–1978, when the disease emerged in these countries. We used a multiscale, geographic information system–based approach to assess the link between cholera outbreaks, climate, and environmental variables. We performed time-series analyses and field investigations in the main affected areas. Results showed that cholera greatly increased during El Niño warm events (abnormally warm El Niños) but decreased or remained stable between these events. Most epidemics occurred in a few hotspots in lakeside areas, where the weekly incidence of cholera varied by season, rainfall, fluctuations of plankton, and fishing activities. During lull periods, persistence of cholera was explained by outbreak dynamics, which suggested a metapopulation pattern, and by endemic foci around the lakes. These links between cholera outbreaks, climate, and lake environments need additional, multidisciplinary study. PMID:22099090

  5. Implementation of an Alert and Response System in Haiti during the Early Stage of the Response to the Cholera Epidemic

    PubMed Central

    Santa-Olalla, Patricia; Gayer, Michelle; Magloire, Roc; Barrais, Robert; Valenciano, Marta; Aramburu, Carmen; Poncelet, Jean Luc; Gustavo Alonso, Juan Carlos; Van Alphen, Dana; Heuschen, Florence; Andraghetti, Roberta; Lee, Robert; Drury, Patrick; Aldighieri, Sylvain

    2013-01-01

    The start of the cholera epidemic in Haiti quickly highlighted the necessity of the implementation of an Alert and Response (A&R) System to complement the existing national surveillance system. The national system had been able to detect and confirm the outbreak etiology but required external support to monitor the spread of cholera and coordinate response, because much of the information produced was insufficiently timely for real-time monitoring and directing of a rapid, targeted response. The A&R System was designed by the Pan American Health Organization/World Health Organization in collaboration with the Haiti Ministry of Health, and it was based on a network of partners, including any institution, structure, or individual that could identify, verify, and respond to alerts. The defined objectives were to (1) save lives through early detection and treatment of cases and (2) control the spread through early intervention at the community level. The operational structure could be broken down into three principle categories: (1) alert (early warning), (2) verification and assessment of the information, and (3) efficient and timely response in coordination with partners to avoid duplication. Information generated by the A&R System was analyzed and interpreted, and the qualitative information was critical in qualifying the epidemic and defining vulnerable areas, particularly because the national surveillance system reported incomplete data for more than one department. The A&R System detected a number of alerts unrelated to cholera and facilitated rapid access to that information. The sensitivity of the system and its ability to react quickly was shown in May of 2011, when an abnormal increase in alerts coming from several communes in the Sud-Est Department in epidemiological weeks (EWs) 17 and 18 were noted and disseminated network-wide and response activities were implemented. The national cholera surveillance system did not register the increase until EWs 21 and

  6. Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

  7. Detection of Antibodies to Toxin-Coregulated Pili in Sera from Cholera Patients

    PubMed Central

    Attridge, Stephen R.; Wallerström, Gun; Qadri, Firdausi; Svennerholm, Ann-Mari

    2004-01-01

    Monoclonal antibodies (MAbs) were prepared against toxin-coregulated pili (TCP) isolated from Vibrio cholerae O1 El Tor. Despite their limited bactericidal potential, two MAbs were able to mediate biotype-specific protection against experimental cholera in infant mice. These MAbs were used in immunoblotting studies to assess seroconversion to El Tor TCP following cholera. Clear anti-pilus responses were observed in five of nine patients. PMID:14977996

  8. Homology between the deoxyribonucleic acid of fertility factor P and Vibrio cholerae chromosomal deoxyribonucleic acid.

    PubMed Central

    Wohhieter, J A; Datta, A; Brenner, D J; Baron, L S

    1975-01-01

    The deoxyribonucleic acid (DNA) of the Vibrio cholerae fertility factor P was isolated by the dye-buoyant density method and hybridized to V. cholerae chromosomal DNA. The DNA of this fertility plasmid had between 35 to 40% homology with the V. cholerae chromosomal DNA. Little or no homology was detected between the P factor DNA and DNA of the Escherichia coli sex factor F. PMID:1092651

  9. Culturable and VBNC Vibrio cholerae: interactions with chironomid egg masses and their bacterial population.

    PubMed

    Halpern, Malka; Landsberg, Ori; Raats, Dina; Rosenberg, Eugene

    2007-02-01

    Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments. Recently, it was found that chironomid (nonbiting midges) egg masses serve as a reservoir for the cholera bacterium and that flying chironomid adults are possible windborne carriers of V. cholerae non-O1 non-O139. Chironomids are the most widely distributed insect in freshwater. Females deposit egg masses at the water's edge, and each egg mass contains eggs embedded in a gelatinous matrix. Hemagglutinin/protease, an extracellular enzyme of V. cholerae, was found to degrade chironomid egg masses and to prevent them from hatching. In a yearly survey, chironomid populations and the V. cholerae in their egg masses followed phenological succession and interaction of host-pathogen population dynamics. In this report, it is shown via FISH technique that most of the V. cholerae inhabiting the egg mass are in the viable but nonculturable (VBNC) state. The diversity of culturable bacteria from chironomid egg masses collected from two freshwater habitats was determined. In addition to V. cholerae, representatives of the following genera were isolated: Acinetobacter, Aeromonas, Klebsiella, Shewanella, Pseudomonas, Paracoccus, Exiguobacterium, and unidentified bacteria. Three important human pathogens, Aeromonas veronii, A. caviae, and A. hydrophila, were isolated from chironomid egg masses, indicating that chironomid egg masses may be a natural reservoir for pathogenic Aeromonas species in addition to V. cholerae. All isolates of V. cholerae were capable of degrading chironomid egg masses. This may help explain their host-pathogen relationship with chironomids. In contrast, almost none of the other bacteria that were isolated from the egg masses possessed this ability. Studying the interaction between chironomid egg masses, the bacteria inhabiting them, and V. cholerae could contribute to our understanding of the nature of the V. cholerae-egg mass interactions. PMID:17186156

  10. Rainfall mediations in the spreading of epidemic cholera

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    Following the empirical evidence of a clear correlation between rainfall events and cholera resurgence that was observed in particular during the recent outbreak in Haiti, a spatially explicit model of epidemic cholera is re-examined. Specifically, we test a multivariate Poisson rainfall generator, with parameters varying in space and time, as a driver of enhanced disease transmission. The relevance of the issue relates to the key insight that predictive mathematical models may provide into the course of an ongoing cholera epidemic aiding emergency management (say, in allocating life-saving supplies or health care staff) or in evaluating alternative management strategies. Our model consists of a set of dynamical equations (SIRB-like i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals, and including a balance of Bacterial concentrations in the water reservoir) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water. These, in turn, are driven by rainfall washout of open-air defecation sites or cesspool overflows, hydrologic transport through waterways and by mobility of susceptible and infected individuals. We perform an a posteriori analysis (from the beginning of the epidemic in October 2010 until December 2011) to test the model reliability in predicting cholera cases and in testing control measures, involving vaccination and sanitation campaigns, for the ongoing epidemic. Even though predicting reliably the timing of the epidemic resurgence proves difficult due to rainfall inter-annual variability, we find that the model can reasonably quantify the total number of reported infection cases in the selected time-span. We then run a multi-seasonal prediction of the course of the epidemic until December 2015, to investigate conditions for further resurgences and endemicity of cholera in the region with a view to policies which may bring to