Evaluating the prevalence and genetic diversity of adenovirus and polyomavirus in bovine waste for microbial source tracking.

This study evaluated and compared the occurrence, concentrations, and genetic diversity of bovine polyomavirus (BPyV) and bovine adenovirus (BAdV) in manure and feces samples for the purpose of determining which of these two viruses is more suitable for bovine fecal indication and microbial source tracking. The comparability and correlation between concentrations/prevalence of these viruses and bacterial fecal indicators (cow-associated Bacteroidetes, Escherichia coli and enterococci) in manure and fecal samples was also determined. A total of 26 dairy manure and 18 individual dairy cow feces samples were tested. The results showed the mean concentration of BAdV in all of dairy manure samples was at least 1 log lower than BPyV (p ≤ 0.005). All of the dairy manure samples tested positive for BPyV but not for BAdV. After combining dairy manure measurements, bacterial indicators had 0.3-0.7 log (p ≤ 0.05) and 1.8-2.2 log (p ≤ 0.005) higher concentrations than BPyV and BAdV, respectively. The concentration of BPyV had a significant positive correlation with the concentration of E. coli and enterococci in the manure samples. The partial VP1 genetic sequences of BPyV isolated from three different farms had a 100% homology to each other and to VP1 sequence (D13942.1) reported in previous study. Based on the occurrence, quantitative and genetic diversity results, BPyV may be a better indicator than BAdV for microbial source tracking at manure application sites.