Bacteroides genetic markers for microbial source tracking fecal pollution in Ontario waters

Abstract

This thesis investigated the laboratory and field validation of a Bacteroides swine marker and developed a Bacteroides chicken marker for microbial source tracking (MST) in Ontario watersheds. The BacSwine genetic marker was validated in the laboratory using 146 fecal samples from target and non-target species. The marker produced a binary sensitivity of 1.0 and a specificity of 0.79 with statistical reasoning to distinguish between true and false positives with > 98% confidence. The BacChicken marker was tested for presence/absence on 35 target and non-target species and produced a sensitivity of 0.92 and specificity of 0.96. The MST BacGeneral, BacBovine, BacHuman, and BacSwine markers were applied in parallel with E. coli at point and non-point locations in the Grand River and a small inland lake watershed. Seasonal changes, land use practices, and land development were likely related to changes in dominant marker abundance specific to sample locations.