1 research outputs found
Performance Characteristics of qPCR Assays Targeting Human- and Ruminant-Associated <i>Bacteroidetes</i> for Microbial Source Tracking across Sixteen Countries on Six Continents
Numerous quantitative PCR assays
for microbial fecal source tracking
(MST) have been developed and evaluated in recent years. Widespread
application has been hindered by a lack of knowledge regarding the
geographical stability and hence applicability of such methods beyond
the regional level. This study assessed the performance of five previously
reported quantitative PCR assays targeting human-, cattle-, or ruminant-associated <i>Bacteroidetes</i> populations on 280 human and animal fecal
samples from 16 countries across six continents. The tested cattle-associated
markers were shown to be ruminant-associated. The quantitative distributions
of marker concentrations in target and nontarget samples proved to
be essential for the assessment of assay performance and were used
to establish a new metric for quantitative source-specificity. In
general, this study demonstrates that stable target populations required
for marker-based MST occur around the globe. Ruminant-associated marker
concentrations were strongly correlated with total intestinal <i>Bacteroidetes</i> populations and with each other, indicating
that the detected ruminant-associated populations seem to be part
of the intestinal core microbiome of ruminants worldwide. Consequently
tested ruminant-targeted assays appear to be suitable quantitative
MST tools beyond the regional level while the targeted human-associated
populations seem to be less prevalent and stable, suggesting potential
for improvements in human-targeted methods