title: A qPCR assay to detect and quantify Shiga toxin-producing E. coli (STEC) in cattle and on farms: a potential predictive tool for STEC culture-positive farms.
abstract: Shiga toxin-producing E. coli (STEC), of various serogroups harboring the intimin gene, form a serious threat to human health. They are asymptomatically carried by cattle. In this study, a quantitative real-time PCR (qPCR) method was developed as a molecular method to detect and quantify Shiga toxin genes stx1 and stx2 and the intimin gene eae. Subsequently, 59 fecal samples from six farms were tested using qPCR and a culture method as a reference. Three farms had contaminated animals as demonstrated by the culture method. Culture-positive farms showed moderate significantly higher stx prevalences than culture-negative farms (p = 0.05). This is the first study which showed preliminary results that qPCR can predict STEC farm contamination, with a specificity of 77% and a sensitivity of 83%, as compared with the culture method. Furthermore, the presence or quantity of stx genes in feces was not correlated to the isolation of STEC from the individual animal. Quantitative data thus did not add value to the results. Finally, the detection of both stx and eae genes within the same fecal sample or farm using qPCR was not correlated with the isolation of an eae-harboring STEC strain from the respective sample or farm using the culture method.
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. karen.verstraete@ilvo.vlaanderen.be.
authors.forename: Karen
authors.initials: K
authors.lastname: Verstraete
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. els.vancoillie@ilvo.vlaanderen.be.
authors.forename: Els
authors.initials: E
authors.lastname: Van Coillie
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. hadewig.werbrouck@ilvo.vlaanderen.be.
authors.forename: Hadewig
authors.initials: H
authors.lastname: Werbrouck
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. stephanie.vanweyenberg@ilvo.vlaanderen.be.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Van Weyenberg
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. lieve.herman@ilvo.vlaanderen.be.
authors.forename: Lieve
authors.initials: L
authors.lastname: Herman
authors.affiliation: Applied Molecular Genomics Group, Department of Molecular Genetics, Flemish Institute for Biotechnology (VIB), Universiteitsplein 1, Antwerpen 2610, Belgium. jurgen.delfavero@molgen.vib-ua.be.
authors.forename: Jurgen
authors.initials: J
authors.lastname: Del-Favero
authors.affiliation: Applied Molecular Genomics Group, Department of Molecular Genetics, Flemish Institute for Biotechnology (VIB), Universiteitsplein 1, Antwerpen 2610, Belgium. Peter.DeRijk@molgen.vib-ua.be.
authors.forename: Peter
authors.initials: P
authors.lastname: De Rijk
authors.affiliation: Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium. lieven.dezutter@ugent.be.
authors.forename: Lieven
authors.initials: L
authors.lastname: De Zutter
authors.affiliation: Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium. adelheid.joris@gmail.com.
authors.forename: Maria-Adelheid
authors.initials: MA
authors.lastname: Joris
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. marc.heyndrickx@ilvo.vlaanderen.be.
authors.forename: Marc
authors.initials: M
authors.lastname: Heyndrickx
authors.affiliation: Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO), Brusselsesteenweg 370, Melle 9090, Belgium. koen.dereu@ilvo.vlaanderen.be.
authors.forename: Koen
authors.initials: K
authors.lastname: De Reu
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D015373:Bacterial Typing Techniques / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification; D003612:Dairying; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D011237:Predictive Value of Tests; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary*; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli