Bovine and Ruminant Tests Used for Microbial Source Tracking at KSU

Microbial source tracking (MST) attempts to identify specific animal sources of fecal contamination in the environment. While traditional fecal coliform enumeration can give a general measure of contamination, the specificity imparted by modern MST provides a more informative assessment of contaminants and their likelihood to affect human health outcomes. We have been developing an MST system that detects DNA biomarkers from the gram-negative bacterial genus Bacteroides and the family Lachnospiraceae. They are strict anaerobes found in large quantities in the intestines of animals. Unlike E. coli or Enterococci, host-specific strains of Bacteroides and Lachnospiraceae exist. To this end, we have been developing species-specific assays that identify the presence of gene sequences uniquely found in these bacteria that are associated with their corresponding host species. We have previously implemented developed five MST tests: human, dog, bird, horse, and general animal. We can also test for SARS-CoV-2 in wastewater using similar methods. Here, we have attempted to develop bovine-specific and ruminant-specific tests. Our experiments confirmed the ability of each new test to detect their target genes, and at a level of detection and quantification similar to that of previously published results. This new combination of tests will also be useful for indirectly assessing the presence of deer DNA biomarkers. Deer are non-bovine ruminants. We can now quantitatively assess the level of species-specific contamination in the environment using seven MST tests: human, dog, bird, horse, total animal, bovine, and ruminants