Wyoming surface water and fecal bacterial communities for source tracking

Waterborne pathogens pose a public health threat, yet management to reduce this threat requires knowledge of contaminant sources which fecal indicator bacteria (i.e., Escherichia coli) cannot provide. In this study, we compared bacterial communities from streams in Wyoming, USA to bacterial communities in possible fecal contamination sources (i.e., fecal samples from different animals) using recently developed microbial source tracking methods. We found that bacterial communities varied across the headwater river network and over the course of a summer season. Wastewater was the most important source of fecal contamination we sampled for, followed by cattle, dogs, and other domesticated and wild animals. In addition to identifying wastewater as an important pollution source, our results suggest that groundwater and surface water connectivity could be an important factor in delivering bacterial contaminants to streams. Overall, new genomic approaches allowed us to understand bacterial contamination in rivers, which is an important public health concern in this region and beyond