title: Performance characteristics of qPCR assays targeting human- and ruminant-associated bacteroidetes for microbial source tracking across sixteen countries on six continents.
abstract: 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 Bacteroidetes 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 Bacteroidetes 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.
authors.affiliation: Research Group Environmental Microbiology and Molecular Ecology, Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Vienna, Austria. reischer@mail.tuwien.ac.at
authors.forename: Georg H
authors.initials: GH
authors.lastname: Reischer
authors.forename: James E
authors.initials: JE
authors.lastname: Ebdon
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Bauer
authors.forename: Nathalie
authors.initials: N
authors.lastname: Schuster
authors.forename: Warish
authors.initials: W
authors.lastname: Ahmed
authors.forename: Johan
authors.initials: J
authors.lastname: Aström
authors.forename: Anicet R
authors.initials: AR
authors.lastname: Blanch
authors.forename: Günter
authors.initials: G
authors.lastname: Blöschl
authors.forename: Denis
authors.initials: D
authors.lastname: Byamukama
authors.forename: Tricia
authors.initials: T
authors.lastname: Coakley
authors.forename: Christobel
authors.initials: C
authors.lastname: Ferguson
authors.forename: Goraw
authors.initials: G
authors.lastname: Goshu
authors.forename: Gwangpyo
authors.initials: G
authors.lastname: Ko
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: de Roda Husman
authors.forename: Douglas
authors.initials: D
authors.lastname: Mushi
authors.forename: Ramiro
authors.initials: R
authors.lastname: Poma
authors.forename: Bandana
authors.initials: B
authors.lastname: Pradhan
authors.forename: Veronica
authors.initials: V
authors.lastname: Rajal
authors.forename: Margit A
authors.initials: MA
authors.lastname: Schade
authors.forename: Regina
authors.initials: R
authors.lastname: Sommer
authors.forename: Huw
authors.initials: H
authors.lastname: Taylor
authors.forename: Erika M
authors.initials: EM
authors.lastname: Toth
authors.forename: Virgil
authors.initials: V
authors.lastname: Vrajmasu
authors.forename: Stefan
authors.initials: S
authors.lastname: Wuertz
authors.forename: Robert L
authors.initials: RL
authors.lastname: Mach
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Farnleitner
mesh_terms: D000818:Animals; D041963:Bacteroidetes / Q000145:classification / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D006801:Humans; D038622:Internationality; D016133:Polymerase Chain Reaction / Q000379:methods*; D012418:Ruminants