trans-Sialidase Neutralizing Antibody Detection in Trypanosoma cruzi-Infected Domestic Reservoirs

Abstract

The detection of Trypanosoma cruzi infection in domestic dogs and cats is relevant to evaluating human transmission risks and the effectiveness of insecticide spraying campaigns. However, the serological assays routinely used are associated with cross-reactivity in sera from mammals infected with Leishmania spp. We used a trans-sialidase inhibition assay (TIA) for T. cruzi diagnosis in serum samples from 199 dogs and 57 cats from areas where these types of infections are endemic. TIA is based on the antibody neutralization of recombinant trans-sialidase, an enzyme that is not detected in the coendemic Leishmania species or Trypanosoma rangeli parasites. T. cruzi infection was also evaluated by conventional serology (CS) (indirect immunofluorescence, indirect hemagglutination, enzyme-linked immunosorbent assay, and immunochromatographic dipstick test) and xenodiagnosis. Sera from 30 dogs and 15 cats from areas where these organisms are not endemic and 5 dogs with visceral leishmaniasis were found to be nonreactive by TIA and CS. Samples from dogs and cats demonstrated 91 and 95% copositivities between TIA and CS, whereas the conegativities were 98 and 97%, respectively. Sera from xenodiagnosis-positive dogs and cats also reacted by TIA (copositivities of 97 and 83%, respectively). TIA was reactive in three CS-negative samples and was able to resolve results in two cat serum samples that were CS inconclusive. Our study is the first to describe the development of trans-sialidase neutralizing antibodies in naturally infected dogs and cats. High CS conegativity and the absence of trans-sialidase neutralization in dog sera from areas where leishmaniasis is not endemic and from dogs with visceral leishmaniasis support TIA specificity. The TIA may be a useful tool for T. cruzi detection in the main domestic reservoirs.

Evaluation of recombinant antigens of Trypanosoma cruzi to diagnose infection in naturally infected dogs from Chaco region, Argentina

“…Although the performance of different recombinant antigens used to detect human infections have been widely examined and validated , they have been scarcely assessed to diagnose infections in dogs. Furthermore, these few reports are hardly comparable as they have been performed using different techniques, such as: ELISA , Western blot , immunochromatography and trans‐sialidase inhibition assay . When serological techniques are applied to large sample sizes, a versatile, simple and economic technique is needed.…”

Trypanosoma cruzi trans-sialidase as a multifunctional enzyme in Chagas’ disease

“…Anti-TS antibodies remain in the chronic phase, when no parasites are detected. Some of these antibodies are inhibitory against TS in human patients and domestic animals (Sartor et al, 2011). This could indicate that TS activity is minimal in chronic infection.…”

“…Some of these antibodies are inhibitory against TS in human patients and domestic animals (Sartor et al, 2011). Some of these antibodies are inhibitory against TS in human patients and domestic animals (Sartor et al, 2011).…”

Detection of Trypanosoma cruzi infection in naturally infected dogs and cats using serological, parasitological and molecular methods

“…The sensitivity of kDNA-PCR reached 100% among T. cruzi -infected infants born to seropositive women (Schijman et al 2003), and rose from 75.6% to 95.6% in chronic patients when the number of serial blood samples tested increased from one to three (Bisio et al 2011). …”