Performance of recombinant chimeric proteins in the serological diagnosis of Trypanosoma cruzi infection in dogs

Abstract

Background Dogs are considered sentinels in areas of Trypanosoma cruzi transmission risk to humans. ELISA is generally the method of choice for diagnosing T . cruzi exposure in dogs, but its performance substantially depends on the antigenic matrix employed. In previous studies, our group has developed four chimeric antigens (IBMP-8.1, 8.2, 8.3, and 8.4) and evaluated their potential for diagnosing T . cruzi exposure in humans. For human sera, these chimeric antigens presented superior diagnostic performances as compared to commercial tests available in Brazil, Spain, and Argentina. Therefore, in this study we have evaluated the potential of these antigenic proteins for detection of anti- T . cruzi IgG antibodies in dog sera. Methodology/Principal findings The IBMP-ELISA assays were optimized by checkerboard titration. Subsequently, the diagnostic potential was validated through analysis of ROC curves and the performance of the tests was determined using double entry tables. Cross-reactivity was also evaluated for babesiosis, ehrlichiosis, dirofilariosis, anaplasmosis, and visceral leishmaniasis. Best performance was shown by IBMP-8.3 and IBMP-8.4, although all four antigens demonstrated a high diagnostic performance with 46 positive and 149 negative samples tested. IBMP-8.3 demonstrated 100% sensitivity, followed by IBMP-8.4 (96.7–100%), IBMP-8.2 (73.3–87.5%), and IBMP-8.1 (50–100%). The highest specificities were achieved with IBMP-8.2 (100%) and IBMP-8.4 (100%), followed by IBMP-8.3 (96.7–97.5%) and IBMP 8.1 (89.1–100%). Conclusions/Significance The use of chimeric antigenic matrices in immunoassays for anti- T . cruzi IgG antibody detection in sera of infected dogs was shown to be a promising tool for veterinary diagnosis and epidemiological studies. The chimeric antigens used in this work allowed also to overcome the common hurdles related to serodiagnosis of T . cruzi infection, especially regarding variation of efficiency parameters according to different strains and cross-reactivity with other infectious diseases.

Assessment of Liaison XL Murex Chagas diagnostic performance in blood screening for Chagas disease using a reference array of chimeric antigens

“…Furthermore, these antigens performed remarkably well when utilized for the serodiagnosis of canine chronic CD in naturally and experimentally infected dog populations across different Brazilian states. 17 The present study endeavored to evaluate, using four chimeric IBMP antigens combined with a latent class analysis (LCA) statistical approach, the performance of the Liaison XL Murex Chagas CLIA to detect anti-T. cruzi IgG in serum samples at a blood bank in Salvador, Bahia-Brazil.…”

Stability Assessment of Four Chimeric Proteins for Human Chagas Disease Immunodiagnosis

“…Chimeric proteins have also been employed in IVD [13][14][15] or as a vaccine [16,17] for other infectious diseases. Considering the predicaments herein set forth, our group expressed four T. cruzi chimeric proteins, called IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4 (Molecular Biology Institute of Paraná-IBMP in Portuguese acronym), and assessed their performance in diagnosis chronic Chagas disease in dogs [18,19] and humans, from several endemic and non-endemic settings from Brazil [20], Argentina, Paraguay, Bolivia [21] and Spain [22].…”

TroCCAP recommendations for the diagnosis, prevention and treatment of parasitic infections in dogs and cats in the tropics

“…However, veterinarians should be aware of possible cross-reactivities (Dantas-Torres et al, 2012;Aroch et al, 2015). For many haemoparasites, serological tests may be available in research laboratories (Leony et al, 2019), but not commercially. For instance, there are no commercial antigen or antibody tests for Hepatozoon spp., Rangelia vitalii, and T. cruzi and therefore blood smear evaluation and/or PCR are required for diagnosis (Baneth, 2011;Eiras et al, 2014).…”