Host-specific mitochondrial DNA markers for tracking the sources of fecal pollution

Epithelial cells that contain a large number of mitochondrial DNA (mtDNA) are shed in host feces. Recently, researchers have developed mtDNA markers targeting mtDNA of specific hosts and applied them to microbial source tracking (MST) for different environmental waters. This review describes the performance, persistence in environmental waters, and correlations of host-specific mtDNA markers with fecal indicators and bacterial MST markers to assess their usefulness in MST. Furthermore, concentrations are summarized for human- and animal-specific mtDNA markers in fecal sources and water that have been reported previously. For accurate identification of pollution sources, the use of host-specific mtDNA markers in combination with other MST markers in a toolbox approach is highly recommended.