Kegg Pathway: Cholera - Environment

Zh Mikrobiol Epidemiol Immunobiol. 2008 May-Jun; 107-14

The review presents data on circulation of antibiotic resistant and susceptible strains of Vibrio Cholerae serogroups O1 and O139 isolated from Cholera patients and healthy persons as well as from the Environment, in Asia, Africa, Australia, and Europe (including New Independent States) during 7th Cholera pandemic.

Infect Immun. 2008 Jun 30;
Larocque RC, Krastins B, Harris JB, Lebrun LM, Parker KC, Chase M, Ryan ET, Qadri F, Sarracino D, Calderwood SB

An effective vaccine for Vibrio Cholerae is not yet available for use in the developing world, where the burden of Cholera disease is highest. Characterizing the proteins that are expressed by V. Cholerae in the human host Environment may provide insight into the pathogenesis of Cholera and assist with the development of an improved vaccine. We analyzed the V. Cholerae proteins present in the stools of 32 patients with clinical Cholera. The V. Cholerae outer membrane porin, OmpU, was identified in all of the human stool samples, and many V. Cholerae proteins were repeatedly identified in separate patient samples. The majority of V. Cholerae proteins identified in human stool are involved in protein synthesis and energy metabolism. A number of proteins involved in the pathogenesis of Cholera, including the A and B subunits of Cholera toxin and the toxin-coregulated pilus, were identified in human stool. In a subset of stool specimens, we also assessed which in vivo-expressed V. Cholerae proteins were recognized uniquely by convalescent, as opposed to acute, sera from Cholera patients. We identified a number of these in vivo-expressed proteins as immunogenic during human infection. To our knowledge, this is the first characterization of the proteome of a pathogenic bacteria recovered from a natural host.

Am J Trop Med Hyg. 2008 May; 78(5): 823-32
Emch M, Feldacker C, Yunus M, Streatfield PK, DinhThiem V, Canh do G, Ali M

Environmental factors have been shown to be related to Cholera and thus might prove useful for prediction. In Bangladesh and Vietnam, temporal Cholera distributions are related to satellite-derived and in-situ Environmental time series data in order to examine the relationships between Cholera and the local Environment. Ordered probit models examine associations in Bangladesh; probit models examine associations at 2 sites in Vietnam. Increases in ocean chlorophyll concentration are related to an increased magnitude of Cholera in Bangladesh. Increases in sea surface temperature are most influential in Hue, Vietnam, whereas increases in river height have a significant role in Nha Trang, Vietnam. Cholera appearance and epidemic magnitude are related to the local Environment. Local Environmental parameters have consistent effects when Cholera is regular and more prevalent in endemic settings, but in situations where Cholera epidemics are rare there are differential Environmental effects.

Expert Rev Vaccines. 2008 May; 7(4): 431-5
Chaignat CL, Monti V, Soepardi J, Petersen G, Sorensen E, Narain J, Kieny MP

Humanitarian aid workers regularly encounter the challenge of setting up functioning surveillance systems immediately after a disaster. Detecting potential outbreaks of diseases, such as Cholera, that might arise from disturbed living conditions, displacement and lack of clean water and sanitation is, therefore, extremely difficult. Fears of Cholera outbreaks are often rife in such conditions and the pertinence of using Cholera vaccines, now available on the market, merit attention. The case of Aceh province, Indonesia, following the 2004 tsunami is examined here: the government of Indonesia decided to carry out a mass vaccination campaign using oral Cholera vaccines, a two-dose product that has not been used widely in the particular circumstances of complex emergencies. The preparation and implementation of this campaign faced many hindrances that unfavorably impacted on the time taken to vaccinate the target population and the costs involved. An estimated 69.3% of the target population received immunization. Evidence gathered during the Aceh campaign could be compared with those of a campaign held in another emergency context--Darfur (Sudan). In spite of many dissimilarities, both experiences illustrate the fact that the question of feasibility and relevance of interventions, as well as prioritization of health needs in complex emergencies, remain crucial to alleviate the affected population's suffering in the most efficient way. Following these two campaigns, WHO recommendations on the use of oral Cholera vaccines in complex emergencies were issued in 2006.

Clin Infect Dis. 2008 Apr 1; 46(7): 970-6
Dechet AM, Yu PA, Koram N, Painter J

BACKGROUND: Infections due to Vibrio species cause an estimated 8000 illnesses annually, often through consumption of undercooked seafood. Like foodborne Vibrio infections, nonfoodborne Vibrio infections (NFVI) also result in serious illness, but awareness of these infections is limited. METHODS: We analyzed illnesses occuring during the period 1997-2006 that were reported to the Centers for Disease Control and Prevention's Cholera and Other Vibrio Illness Surveillance system. The diagnosis of NFVI required isolation of Vibrio species from a patient with contact with seawater. RESULTS: Of 4754 Vibrio infections reported, 1210 (25%) were NFVIs. Vibrio vulnificus infections were the most common (accounting for 35% of NFVIs), with 72% of V. vulnificus infections reported from residents of Gulf Coast states. Infections due to V. vulnificus resulted in fever (72% of cases), cellulitis (85%), amputation (10%), and death (17%). V. vulnificus caused 62 NFVI-associated deaths (78%). Recreational activities accounted for 70% of exposures for patients with NFVIs associated with all species. Patients with liver disease were significantly more likely to die as a result of infection (odds ratio, 7.8; 95% confidence interval, 2.8-21.9). Regardless of pre-existing conditions, patients were more likely to die when hospitalization occurred >2 days after symptom onset (odds ratio, 2.9; 95% confidence interval, 1.8-4.8). CONCLUSION: NFVIs, especially those due to V. vulnificus, demonstrate high morbidity and mortality. Persons with liver disease should be advised of the risks associated with seawater exposure if a wound is already present or is likely to occur. Clinicians should consider Vibrio species as an etiologic agent in infections occurring in persons with recent seawater exposure, even if the individual was only exposed during recreational marine activities. Immediate antibiotic treatment with aggressive monitoring is advised in suspected cases.

Emerg Infect Dis. 2008 May; 14(5): 831-3
Stine OC, Alam M, Tang L, Nair GB, Siddique AK, Faruque SM, Huq A, Colwell R, Sack RB, Morris JG

Clinical and Environmental Vibrio Cholerae organisms collected from February 2004 through April 2005 were systematically isolated from 2 rural Bangladeshi locales. Their genetic relatedness was evaluated at 5 loci that contained a variable number of tandem repeats (VNTR). The observed minimal overlap in VNTR patterns between the 2 communities was consistent with sequential, small outbreaks from local sources.

Emerg Infect Dis. 2008 May; 14(5): 798-800
Bompangue D, Giraudoux P, Handschumacher P, Piarroux M, Sudre B, Ekwanzala M, Kebela I, Piarroux R

We studied the epidemiology of Cholera in Katanga and Eastern Kasai, in the Democratic Republic of Congo, by compiling a database including all cases recorded from 2000 through 2005. Results show that lakes were the sources of outbreaks and demonstrate the inadequacy of the strategy used to combat Cholera.

Appl Biochem Biotechnol. 2008 Apr 10;
Kumar P, Peter WA, Thomas S

Vibrio Cholerae is the etiologic agent of Cholera. It is an autochthonous inhabitant of all aquatic Environments. The virulence of V. Cholerae is maintained by the CTX genetic element and tcpA gene. In the present investigation, Environmental strains of V. Cholerae isolated from different aquatic biotopes in Kerala were identified and serotyped. The antibiotic resistance pattern and presence of virulence and regulatory genes were examined. We found the presence of toxigenic non-O1/non-O139 strains harboring the CTX genetic element, heat-stable enterotoxin, rtxA gene, El Tor hemolysin, and Vibrio pathogenicity island (VPI). The strains also produced the Cholera toxin (CT) as determined by monosialoganglioside enzyme-linked immunosorbent assay. A few strains belonging to the O1 serogroup but lacking the CTX genetic element were also observed. The majority of the Environmental strains belonged to non-O1/non-O139 serogroup with many possessing toxR, ompU, heat-stable enterotoxin, and rtxA gene. The toxigenic non-O1/non-O139 strains exhibited resistance to trimethoprim, ampicillin, and polymixin B and intermediate resistance to co-trimoxazole. However, all other Environmental strains were found resistant to ampicillin and polymixin B. Our findings demonstrate that the virulence genes are dispersed among the Environmental strains of V. Cholerae and a complex aquatic Environment can give rise to pathogenic V. Cholerae.

J Water Health. 2008; 6(4): 559-564
Steele A, Clarke B, Watkins O

In July 2007, a study by the Centre for Environmental Health Engineering, at the University of Surrey, assessed a modified method of jerry can cleaning in an internally displaced persons (IDP) camp in Kitgum, N. Uganda. The poor condition of drinking water vessels used in the camp was confirmed as a potential source for microbiological contamination both visually and by microbiological testing. Jerry cans were disinfected using high strength sodium hypochlorite (NaOCl) generated using an experimental AquaChlor Solar unit. The study suggested that regular jerry can cleaning, using a high strength chlorine based disinfectant, offers an effective method of alleviating the adverse effects of contamination in water collection and storage vessels. Results indicated that the method is capable of significantly reducing thermo-tolerant coliform numbers to below 5 cfu/100 ml in most cases. Chlorine strength depletion after repetitive cleaning confirms the impact of process. The method does not substitute for good hygiene practices, which are essential for maintaining water quality in the household. It is suggested that the process can play an important role during outbreaks of water-borne diseases, such as Cholera, particularly if combined with regular water disinfection.

Transplantation. 2008 Feb 27; 85(4): 656
Sundaram M, Veeraraghavan B, John GT

Lancet. 2008 Mar 8; 371(9615): 799-800
Schatz JJ

Exp Cell Res. 2008 Apr 15; 314(7): 1465-79
de Diesbach P, Medts T, Carpentier S, D'Auria L, Van Der Smissen P, Platek A, Mettlen M, Caplanusi A, van den Hove MF, Tyteca D, Courtoy PJ

Most Src family members are diacylated and constitutively associate with membrane "lipid rafts" that coordinate signalling. Whether the monoacylated Src, frequently hyperactive in carcinomas, also localizes at "rafts" remains controversial. Using polarized MDCK cells expressing the thermosensitive v-Src/tsLA31 variant, we here addressed how Src tyrosine-kinase activation may impact on its (i) membrane recruitment, in particular to "lipid rafts"; (ii) subcellular localization; and (iii) signalling. The kinetics of Src-kinase thermoactivation correlated with its recruitment from the cytosol to sedimentable membranes where Src largely resisted solubilisation by non-ionic detergents at 4 degrees C and floated into sucrose density gradients like caveolin-1 and flotillin-2, i.e. "lipid rafts". By immunofluorescence, activated Src showed a dual localization, at apical endosomes/macropinosomes and at the apical plasma membrane. The plasma membrane Src pool did not colocalize with caveolin-1 and flotillin-2, but extensively overlapped GM1 labelling by Cholera toxin. Severe ( approximately 70%) cholesterol extraction with methyl-beta-cyclodextrin (MbetaCD) did not abolish "rafts" floatation, but strongly decreased Src association with floating "rafts" and abolished its localization at the apical plasma membrane. Src activation independently activated first the MAP-kinase - ERK1/2 pathway, then the PI3-kinase - Akt pathway. MAP-kinase - ERK1/2 activation was insensitive to MbetaCD, which suppressed Akt phosphorylation and apical endocytosis induced by Src, both depending on the PI3-kinase pathway. We therefore suggest that activated Src is recruited at two membrane compartments, allowing differential signalling, first via ERK1/2 at "non-raft" domains on endosomes, then via PI3-kinase-Akt on a distinct set of "rafts" at the apical plasma membrane. Whether this model is applicable to c-Src remains to be examined.

Environ Microbiol. 2008 Jun; 10(6): 1400-10
Pruzzo C, Vezzulli L, Colwell RR

The interaction of Vibrio Cholerae with chitin exemplifies for microbial ecology a successful bacteria-substrate interaction with complex and significant influence on the lifestyle of the bacterium. Chitin is one of the most abundant polymers on earth and possibly the most abundant in the aquatic Environment, where its association with V. Cholerae has provided the microorganism with a number of advantages, including food availability, adaptation to Environmental nutrient gradients, tolerance to stress and protection from predators. Emergent properties of V. Cholerae-chitin interactions occur at multiple hierarchical levels in the Environment and include cell metabolic and physiological responses e.g. chemotaxis, cell multiplication, induction of competence, biofilm formation, commensal and symbiotic relationship with higher organisms, cycling of nutrients, and pathogenicity for humans and aquatic animals. As factors mediating virulence of V. Cholerae for humans and aquatic animals derive from mechanisms of adaptation to its Environment, at different levels of hierarchical scale, V. Cholerae interactions with chitin represent a useful model for examination of the role of primary habitat selection in the development of traits that have been identified as virulence factors in human disease.

BMJ. 2008 Mar 1; 336(7642): 471
Sidley P

Zh Mikrobiol Epidemiol Immunobiol. 2007 Nov-Dec; 20-6
Smirnova NI, Osin AV, Nefedov KS, Kul'shan' TA, Zadnova SP, Livanova LF, Toporkov AV, Kutyrev VV

Comparative analysis of CTXphi prophage genome of 366 V. Cholerae El Tor strains isolated from infected people and water was carried out using the polymerase chain reaction. Four groups of vibrios, which carry different combinations of ctxA, zot, and ace genes from core region of CTXphi prophage coding key (Cholera enterotoxin) and accessory (Zot and Ace toxins) pathogenicity factors, were determined: ctxA(+) zot(-) ace(+), ctxA(-) zot(+) ace(+), ctxA(-) zot(+) ace(-), ctxA(-) zot(-) ace(+). Vibrios that had lost all tested genes were also revealed. Genomic rearrangements occurring in water Environment in virulent V. Cholerae strains, which acquired foreign pathogenicity genes necessary for their existence in human organism, were proposed as one of the mechanisms of formation of clones with an incomplete or no prophage. Infection process in model animals challenged with wild and isogenic strains of V. Cholerae differing in the set of the phage genes (ctxA, zot, and ace) was comparatively analyzed. It was shown that variability of CTXphi prophage genome was an important factor of modification of Cholera vibrios virulent characteristics. Obtained data point to usefulness of ctxA, zot, and ace phage genes detection in wild V. Cholerae isolates as it could permit evaluation of their virulent potential determining the severity of the infection.

Comp Immunol Microbiol Infect Dis. 2008 Feb 13;
Zhao ZZ, Zhang HB, Chen Q, Su D, Xie Z, Wang YY, Yang Y, Wang ZZ, Li JL, Wu KY, Wang HN, Meng MJ, Gao R

A novel oligodeoxynuleotides containing 11 CpG motifs was synthesized and inserted into the VR1020 plasmid containing pig interleukin-6 (IL-6) gene (VPIL6) to construct recombinant plasmid, VPIL6C. The chitosan nanoparticles (CNP) were prepared by ionic cross linkage to entrap the VPIL6C (VPIL6C-CNP), VPIL6 (VPIL6-CNP) and CpG (CpG-CNP). 42-Day old female mice were divided into four groups and intramuscularly injected respectively with 6pmol VPIL6C-CNP, VPIL6-CNP, CpG-CNP and VR1020-CNP along with the bivalent vaccines against the Pasteurellosis and hog Cholera. The blood was weekly collected from mice after vaccination to detect the changes of immunoglobulins, specific antibodies, IL-2, IL-4, IL-6 and immune cells. 28 days after vaccination, the mice were orally challenged with virulent Pasteurella multocida. The results showed that in comparison with those of the control VR1020 group, the content of immunoglobulins, specific antibodies and interleukins significantly increased in the sera from the treated two groups (P<0.05). Meanwhile, the number of lymphocytes and monocytes also remarkably elevated in the treated groups (P<0.05). The immune responses of VPIL6C mice were notably stronger than those of VPIL6 and CpG group. The challenge results proved that the overall immunity was further promoted in the treated mice which resisted the challenge infection; while the control mice manifested evident symptoms and lesions, and died of infection. These suggested that VPIL6C-CNP could better promote the immunity and resistance of mice against Pasteurellosis than VPIL6-CNP and CpG-CNP, and facilitate the development of effective adjuvant to enhance the immunity of animal against infection.

J Biol Chem. 2008 Apr 18; 283(16): 10671-8
Jørgensen R, Purdy AE, Fieldhouse RJ, Kimber MS, Bartlett DH, Merrill AR

The ADP-ribosyltransferases are a class of enzymes that display activity in a variety of bacterial pathogens responsible for causing diseases in plants and animals, including those affecting mankind, such as diphtheria, Cholera, and whooping cough. We report the characterization of a novel toxin from Vibrio Cholerae, which we call cholix toxin. The toxin is active against mammalian cells (IC(50) = 4.6 +/- 0.4 ng/ml) and crustaceans (Artemia nauplii LD(50) = 10 +/- 2 mug/ml). Here we show that this toxin is the third member of the diphthamide-specific class of ADP-ribose transferases and that it possesses specific ADP-ribose transferase activity against ribosomal eukaryotic elongation factor 2. We also describe the high resolution crystal structures of the multidomain toxin and its catalytic domain at 2.1- and 1.25-A resolution, respectively. The new structural data show that cholix toxin possesses the necessary molecular features required for infection of eukaryotes by receptor-mediated endocytosis, translocation to the host cytoplasm, and inhibition of protein synthesis by specific modification of elongation factor 2. The crystal structures also provide important insight into the structural basis for activation of toxin ADP-ribosyltransferase activity. These results indicate that cholix toxin may be an important virulence factor of Vibrio Cholerae that likely plays a significant role in the survival of the organism in an aquatic Environment.

Appl Environ Microbiol. 2008 Apr; 74(7): 2004-15
Kirschner AK, Schlesinger J, Farnleitner AH, Hornek R, Süss B, Golda B, Herzig A, Reitner B

Vibrio Cholerae non-O1/non-O139 strains have caused several cases of ear, wound, and blood infections, including one lethal case of septicemia in Austria, during recent years. All of these cases had a history of local recreational activities in the large eastern Austrian lake Neusiedler See. Thus, a monitoring program was started to investigate the prevalence of V. Cholerae strains in the lake over several years. Genetic analyses of isolated strains revealed the presence of a variety of pathogenic genes, but in no case did we detect the Cholera toxin gene or the toxin-coregulated pilus gene, both of which are prerequisites for the pathogen to be able to cause Cholera. In addition, experiments were performed to elucidate the preferred ecological niche of this pathogen. As size filtration experiments indicated and laboratory microcosms showed, endemic V. Cholerae could rapidly grow in a free-living state in natural lake water at growth rates similar to those of the bulk natural bacterial population. Temperature and the quality of dissolved organic carbon had a highly significant influence on V. Cholerae growth. Specific growth rates, growth yield, and enzyme activity decreased markedly with increasing concentrations of high-molecular-weight substances, indicating that the humic substances originating from the extensive reed belt in the lake can inhibit V. Cholerae growth.

J Mol Biol. 2008 Mar 14; 377(1): 91-103
Yanez ME, Korotkov KV, Abendroth J, Hol WG

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

Infect Immun. 2008 Apr; 76(4): 1617-27
Tamayo R, Schild S, Pratt JT, Camilli A

In Vibrio Cholerae, the second messenger cyclic di-GMP (c-di-GMP) positively regulates biofilm formation and negatively regulates virulence and is proposed to play an important role in the transition from persistence in the Environment to survival in the host. Herein we describe a characterization of the infection-induced gene cdpA, which encodes both GGDEF and EAL domains, which are known to mediate diguanylate cyclase and c-di-GMP phosphodiesterase (PDE) activities, respectively. CdpA is shown to possess PDE activity, and this activity is regulated by its inactive degenerate GGDEF domain. CdpA inhibits biofilm formation but has no effect on colonization of the infant mouse small intestine. Consistent with these observations, cdpA is expressed during in vitro growth in a biofilm but is not expressed in vivo until the late stage of infection, after colonization has occurred. To test for a role of c-di-GMP in the early stages of infection, we artificially increased c-di-GMP and observed reduced colonization. This was attributed to a significant reduction in toxT transcription during infection. Cumulatively, these results support a model of the V. Cholerae life cycle in which c-di-GMP must be down-regulated early after entering the small intestine and maintained at a low level to allow virulence gene expression, colonization, and motility at appropriate stages of infection.