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dc.contributor.advisorBénié, Goze Bertinfr
dc.contributor.authorBonfils, Djoanfr
dc.date.accessioned2014-09-09T15:31:41Z
dc.date.available2014-09-09T15:31:41Z
dc.date.created2012fr
dc.date.issued2012fr
dc.identifier.isbn9780494910030fr
dc.identifier.urihttp://hdl.handle.net/11143/5706
dc.description.abstractBackground : The sources and the epidemiology of Campylobacter jejuni (CJ) in environmental water are not well understood. We developed a spatial analysis methodology able to identify the main environmental factors predicting the presence and quantity of Campylobacter in river water. Methods : For two years, water samples were collected weekly and scanned for CJ and fecal coliforms at 32 sampling sites of Estrie hydrographic network, Québec. The quantity of CJ in water was estimated using the Most Probable Number method (MPN). The 32 sampling sites were linked to their catchment area; 10 of them were excluded from the analysis, because their hydrographic basin was not independent from the other sites. For each site, the following environmental variables were included: Water flow, slope, land-cover, land-use including type of farming, animal density, total precipitation in the 3 days prior to water sampling. A stepwise multivariate regression was realized across the different analysis windows to define the size of the area upstream from the sampling sites (from 1.5 to 24 km) which was the most closely associated with the mean quantity of CJ, and which environmental factors were associated with a higher mean quantity of CJ in water. Results : Preliminary results show that an area defined by a radius of 14 km upstream of the sample site was the most contributing zone for the bacteria (r2=0.38, p=0.002). Within this 14 km area, the only significant variable associated with a higher mean quantity of CJ was bovine density (p=0.002). When analyzing the data within a 120 m buffer zone across 14 km upstream of the sampling sites (r2=0.40, p=0.001), the only significant variable associated with a higher mean quantity of CJ was the percentage of agricultural surface (p=0.001). Conclusions : These results suggest a strong implication of bovine density in conjunction with crops and associated manure spreading on the quantity of CJ in environmental water.fr
dc.language.isofrefr
dc.publisherUniversité de Sherbrookefr
dc.rights© Djoan Bonfilsfr
dc.subjectÉpidémiologiefr
dc.subjectAnalyse spatialefr
dc.subjectUtilisation des solsfr
dc.subjectBassins versantsfr
dc.subjectBactériesfr
dc.subjectContamination bactériennefr
dc.subjectCampylobacterfr
dc.titleIdentification des facteurs environnementaux responsables de la présence de Campylobacter Jéjuni dans les eaux de surface de l'Estrie (Québec)fr
dc.typeMémoirefr
tme.degree.disciplineGéomatique appliquéefr
tme.degree.grantorFaculté des lettres et sciences humainesfr
tme.degree.levelMaîtrisefr
tme.degree.nameM. Sc.fr


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