PHYLOGENOMIC AND STRUCTURAL ANALYSES OF VIBRIO CHOLERAE POPULATIONS AND ENDEMIC CHOLERA

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dc.contributor.advisorColwell, Rita Ren_US
dc.contributor.authorZo, Young-Gunen_US
dc.contributor.departmentMarine-Estuarine-Environmental Sciencesen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2006-02-04T06:48:58Z
dc.date.available2006-02-04T06:48:58Z
dc.date.issued2005-11-10en_US
dc.description.abstractCholera is a serious public health problem because of the high burden of morbidity. Recurrent pandemic cholera is sustained by an endemic epicenter in the Bay of Bengal region but the mechanism of endemism is not clearly understood. Recent information showing that the dynamics and seasonality of endemic cholera are linked with environmental parameters led to the hypothesis that the population dynamics of V. cholerae, the causative agent of cholera indigenous in natural aquatic environments, is the link causing variation in endemic cholera. To substantiate this hypothesis, the structure and dynamics of V. cholerae populations in the aquatic environments were investigated, employing three approaches. First, the phylogeny of the family Vibrionaceae was analyzed to determine the phylogenetic boundary of V. cholerae. Phylogeny analysis using comparative genomics revealed that the species, V. cholerae, is a direct descendant of a common ancestor of the genus, with at least 25% of its genome subject to horizontal gene transfer from other vibrios. The second approach was analysis of the population structure of V. cholerae using genomic fingerprinting, with the conclusion that there is a multilayered clonality and paraphyla within the species, with a subvar branch, V. mimicus. It was also concluded that all of the epidemic lineages of V. cholerae are highly clonal, forming a tight phylogenetic compartment. The nonpathogenic clones were found to be highly diverse and some showed significant association with fluctuations observed in the potential-host crustacean zooplankton compositions. Finally, analyses of both the dynamics and compartmentalization of V. cholerae populations during endemic cholera outbreaks yielded a compartmentalized understanding of the mechanism of endemic cholera, namely that there are bodies of water in a cholera endemic area that serve as a reservoir of the bacterium and, therefore, a point source for the seasonal spread of cholera bacteria. The nature of a universal seasonal forcing that repeats the spread of the cholera bacterium from the point source each cholera season is not clear. Further study is recommended to identify those factors that determine both the point source reservoir and the mode of transportation resulting in spread of contaminated water from the reservoir.en_US
dc.format.extent2517623 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/1903/3090
dc.language.isoen_US
dc.subject.pqcontrolledBiology, Microbiologyen_US
dc.subject.pqcontrolledBiology, Ecologyen_US
dc.subject.pquncontrolledgenomic fingerprintingen_US
dc.subject.pquncontrolledpopulation strucutureen_US
dc.subject.pquncontrolledendemic choleraen_US
dc.subject.pquncontrolledphylogenomicsen_US
dc.subject.pquncontrolledlateral gene transferen_US
dc.subject.pquncontrolledfounder flushen_US
dc.titlePHYLOGENOMIC AND STRUCTURAL ANALYSES OF VIBRIO CHOLERAE POPULATIONS AND ENDEMIC CHOLERAen_US
dc.typeDissertationen_US

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