High abundance of genetic Bacteroidetes markers for total fecal pollution in pristine alpine soils suggests lack in specificity for feces

Two frequently applied genetic Bacteroidetes markers for total fecal pollution (AllBac and BacUni) were found in high numbers in pristine soil samples of two alpine catchment areas casting doubt on their value as fecal indicators. This finding underlines the necessity to evaluate assays locally and against non-intestinal samples before application.