Beschreibung:
<jats:title>Abstract</jats:title><jats:p><jats:italic>Bacteroides</jats:italic> spp. have been proposed as indicators of fecal contamination in microbial source tracking (<jats:styled-content style="fixed-case">MST</jats:styled-content>) methodologies. The aim of this study was to develop new <jats:styled-content style="fixed-case">qPCR</jats:styled-content> assays that target host‐specific Bacteroidal 16S ribosomal <jats:styled-content style="fixed-case">RNA</jats:styled-content> genes, to determine the source of fecal contamination in water. Denaturing gradient gel electrophoresis (<jats:styled-content style="fixed-case">DGGE</jats:styled-content>) was used to select for host‐specific bands of <jats:italic>Bacteroides</jats:italic> associated with a fecal pollution source and later to design four <jats:styled-content style="fixed-case">qPCR</jats:styled-content> host‐specific assays. A set of common primers for <jats:italic>Bacteroides</jats:italic> spp., four different <jats:italic>Bacteroides</jats:italic> spp. host‐associated hydrolysis probes (human, cattle, pig, and poultry), and one hydrolysis probe for the <jats:italic>Bacteroides</jats:italic> genus were designed. This set of <jats:styled-content style="fixed-case">qPCR</jats:styled-content> assays together with other previously developed Bacteroidetes <jats:styled-content style="fixed-case">MST</jats:styled-content> targets were used to analyze water samples with fecal contamination from the four sources studied. The host‐specific <jats:italic>Bacteroides </jats:italic><jats:styled-content style="fixed-case">qPCR</jats:styled-content>s designed for human (<jats:styled-content style="fixed-case">HM</jats:styled-content>probeBac), pig (<jats:styled-content style="fixed-case">PG</jats:styled-content>probeBac), and poultry (<jats:styled-content style="fixed-case">PL</jats:styled-content>probeBac) were highly specific for its sources (1.0, 0.97, and 1.0, respectively) although its sensitivity was lower (0.45, 0.50, and 0.73, respectively). The cattle‐specific <jats:styled-content style="fixed-case">qPCR</jats:styled-content> was totally unspecific and was discarded for future experiments. When compared to previously designed assays, the human and pig <jats:styled-content style="fixed-case">qPCR</jats:styled-content>s showed better accuracies (0.86 and 0.84) than their counterparts <jats:styled-content style="fixed-case">HF</jats:styled-content>183 and Pig‐2‐Bac (0.38 and 0.65). Thus, the newly designed human, pig, and poultry <jats:styled-content style="fixed-case">qPCR</jats:styled-content> assays outperform other methods developed until date and may be useful for source tracking purposes.</jats:p>