title: Development of a multiplex fluorescence immunological assay for the simultaneous detection of antibodies against Cooperia oncophora, Dictyocaulus viviparus and Fasciola hepatica in cattle.
abstract: BACKGROUND
  A major constraint for the effective control and management of helminth parasites is the lack of rapid, high-throughput, routine diagnostic tests to assess the health status of individual animals and herds and to identify the parasite species responsible for these helminthoses. The capability of a multiplex platform for the simultaneous detection of three pasture associated parasite species was evaluated and compared to existing ELISAs.
  
  
  METHODS
  The recombinant antigens 14.2 kDa ES protein for Cooperia oncophora, major sperm protein for Dictyocaulus viviparus and Cathepsin L1 for Fasciola hepatica were recombinantly expressed either in Escherichia coli or Pichia pastoris. Antigens were covalently coupled onto magnetic beads. Optimal concentrations for coupling were determined following the examination of serum samples collected from experimentally mono-infected animals, before and after their infection with the target species. Absence of cross-reactivity was further determined with sera from calves mono-infected with Haemonchus contortus, Ostertagia ostertagi and Trichostrongylus colubriformis. Examination of negative serum samples was characterised by low median fluorescence intensity (MFI).
  
  
  RESULTS
  Establishment of the optimal serum dilution of 1:200 was achieved for all three bead sets. Receiver Operating Characteristic analyses were performed to obtain cut-off MFI values for each parasite separately. Sensitivity and specificity at the chosen cut-off values were close to, or 100% for all bead sets. Examination of serum samples collected on different days post infection from different animals showed a high reproducibility of the assays. Serum samples were additionally examined with two already established ELISAs, an in-house ELISA using the recombinant MSP as an antigen and a DRG ELISA using Cathepsin L1 for liver fluke. The results between the assays were compared and kappa tests revealed an overall good agreement.
  
  
  CONCLUSIONS
  A versatile bead-based assay using fluorescence detection (xMAP technology) was developed to simultaneously detect antibodies against C. oncophora, D. viviparus and F. hepatica in cattle serum samples. This platform provides rapid, high-throughput results and is highly sensitive and specific in comparison to existing serological as well as coproscopical diagnostic techniques.
authors.affiliation: Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany. Sofia.Karanikola@fu-berlin.de.
authors.forename: Sofia N
authors.initials: SN
authors.lastname: Karanikola
authors.affiliation: Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany. Juergen.kruecken@fu-berlin.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Krücken
authors.affiliation: Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany. Sabrina.ramuenke@fu-berlin.de.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Ramünke
authors.affiliation: UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Dublin, Ireland. theo.dewaal@ucd.ie.
authors.forename: Theo
authors.initials: T
authors.lastname: de Waal
authors.affiliation: Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology (SWEPAR), Swedish University of Agricultural Sciences, Uppsala, Sweden. Johan.Hoglund@slu.se.
authors.forename: Johan
authors.initials: J
authors.lastname: Höglund
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium. johannes.charlier@UGent.be.
authors.forename: Johannes
authors.initials: J
authors.lastname: Charlier
authors.affiliation: LABOKLIN GMBH & Co.KG, Bad Kissingen, Germany. weber@laboklin.de.
authors.forename: Corinna
authors.initials: C
authors.lastname: Weber
authors.affiliation: LABOKLIN GMBH & Co.KG, Bad Kissingen, Germany. mueller@laboklin.de.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Müller
authors.affiliation: Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Science, Warsaw, Poland. slawomirjankowalczyk@10g.pl.
authors.forename: Slawomir J
authors.initials: SJ
authors.lastname: Kowalczyk
authors.affiliation: Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Science, Warsaw, Poland. jaroslaw_kaba@sggw.pl.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Kaba
authors.affiliation: Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany. gvsamson@fu-berlin.de.
authors.forename: Georg
authors.initials: G
authors.lastname: von Samson-Himmelstjerna
authors.affiliation: Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany. j.demeler@fu-berlin.de.
authors.forename: Janina
authors.initials: J
authors.lastname: Demeler
mesh_terms: D000723:Ancylostomatoidea / Q000276:immunology / Q000302:isolation & purification*; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis* / Q000469:parasitology; D004021:Dictyocaulus / Q000276:immunology / Q000302:isolation & purification*; D004022:Dictyocaulus Infections / Q000097:blood / Q000175:diagnosis* / Q000469:parasitology; D005210:Fasciola hepatica / Q000276:immunology / Q000302:isolation & purification*; D005211:Fascioliasis / Q000097:blood / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D006725:Hookworm Infections / Q000097:blood / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D007159:Immunologic Tests / Q000295:instrumentation / Q000379:methods*; D008297:Male; D012680:Sensitivity and Specificity
chemical_list: D000947:Antigens, Helminth