Fig 1.
SDS-PAGE stained with Coomassie brilliant showing the chimeric purified antigens.
The T. cruzi proteins whose antigenic regions were used to construct the chimeric antigens are described on the right. Lanes 8.1 to 8.4 indicate the IBMP multi-epitope antigens (1 μg of each antigen was loaded per lane). MM: molecular weight marker.
Fig 2.
STARD flowchart to evaluate the diagnostic performance of IBMP chimeric antigens to detect anti-Trypanosoma cruzi antibodies in dog sera.
Reference Standard Tests: in-house ELISA using fractionated lysates of T. cruzi at the epimastigote and modified Gold ELISA Chagas (Rem Indústria e Comércio, Brazil).
Fig 3.
Reactivity index and diagnostic performance parameters obtained with serum samples from T. cruzi-infected and non-infected dogs.
Panel 1 (dogs experimentally infected with Y, Berenice, and Colombian T. cruzi strains); Panel 2 (dogs naturally infected with unknown T. cruzi strains). The cut-off is set at the reactivity index value = 1.0 and the shadowed area represents the grey zone (RI = 1.0 ± 0.10). Horizontal lines and numbers for each result group represent the geometric means (± 95% CI). Acc (accuracy); AUC (area under curve); Sen (sensitivity); Spe (specificity); TcP (T. cruzi-positive samples); TcN (T. cruzi-negative samples).
Fig 4.
Reactivity index for antigen performance for the different Trypanosoma cruzi strains tested.
The cut-off is set at the reactivity index value = 1.0 and the shadowed area represents the grey zone (RI = 1.0 ± 0.10). Horizontal lines and numbers for each results group represent the geometric means (± 95% CI). CI (confidence interval); Sen (sensitivity).
Fig 5.
Analysis of IBMP chimeric antigens cross-reactivity with sera from dogs affected by unrelated parasites infection.
The cut-off value is reactivity index = 1.0 and the shadowed area represents the grey zone (RI = 1.0 ± 0.10). ANA (anaplasmosis); BAB (babesiosis); DIR (dirofilariosis); EHR (ehrlichiosis); LEI (leishmaniasis).