Three tributaries of the Grand River watershed (Ontario, Canada), each representing different\nwatershed types (urban, agricultural/rural, and mixed land-use) were examined to understand\nthe spatial, temporal, and host-source distribution of the waterborne pathogen, Cryptosporidium.\nCryptosporidium was frequently found throughout the study (73%, 65/89) with occurrence and\nconcentrations observed to be similar among the varying watershed types. However, applying advanced\ngenotyping techniques, marked differences in dominant host sources could be observed in\neach watershed. The agricultural/rural and mixed land-use watersheds were dominated by genotypes\ntypically associated with cattle (i.e., C. andersoni), while the urban watershed had the highest\ndiversity of Cryptosporidium genotypes with a variety of wildlife as the common source of contamination\n(e.g., muskrat and cervine genotypes). A similar seasonal trend observed in the urban,\nagricultural, and mixed land-use watershed suggests that factors beyond specific land use activities\n(e.g. autumn manure spreading) may influence the timing and concentration of Cryptosporidium\nin these streams. Corresponding genotyping results provided additional insight into source\ninputs during these seasonal peaks, indicating that wildlife may be important seasonal contributors\nto Cryptosporidium contamination in these streams. Despite the abundance of Cryptosporidium\nin these watersheds, most of the genotypes observed were of limited human health importance.\nThis study provides evidence regarding the significance of including genotyping results into\nstudies examining waterborne Cryptosporidium. Using this technique can provide a greater un-derstanding of the risk to the population using water sources, as well as provide insight into the\nprobable sources and timing of contamination. This ancillary information can contribute to implementation\nof targeted management strategies to further protect sources of drinking water and\nrecreation areas.
Loading....