Trypanosoma vivax infection in dairy cattle: Parasitological and serological diagnosis and its relationship with the percentage of red blood cells.

Trypanosoma vivax is an emerging infectious agent in Brazil. Trypanosomosis kills cattle, especially in regions where the protozoan is unknown and herd immunity does not occur. The present study aims to report infection by T. vivax in dairy cattle from Santa Catarina, Brazil, and evaluate the effects on the percentage of red cells in the blood. Was analyzed 146 cattle blood samples with a clinical diagnosis of anaemia (pale pink mucosa: ocular and vaginal) using indirect immunofluorescence assay PCR and blood smear. 39% of the samples were positive by IFA, but none of them were positive by PCR. It was possible to verify the presence of trypomastigote forms of parasite in 3 samples of cows positive by IFA. The percentage of red cells (hematocrit) did not differ between animals with a positive serological diagnosis compared to seronegative ones. Regardless of the concentration of antibodies, hematocrit did not differ. Another piece of information that drew attention was the hematocrit of the three animals with a parasitological diagnosis. That is, these animals had a percentage of red cells of 35, 38, 39%. Among the symptomatic animals evaluated, 11 had fever and anorexia, cows that presented hematocrit between 21 and 30%. This is the first description of infection in cattle in Santa Catarina, Brazil. Anaemia is not a clinical finding in asymptomatic dairy cows but seroreactive for T. vivax.

Effects of resveratrol on the differentiation fate of neural progenitor cells of mouse embryos infected with Trypanosoma cruzi.

Chagas disease (CD) affecting about 7 million people is caused by the flagellate protozoan Trypanosoma cruzi. The central nervous system (CNS) is an important site for T. cruzi persistence in the host during the chronic phase of infection, because the protozoan may pass the blood-brain barrier and may cause motor and cognitive neuronal damage. Thinking about avoiding or minimizing these negative effects, it is hypothesized that resveratrol (RSV), a component with several medicinal properties has beneficial effects on the CNS. The objective of this study was to investigate, whether T. cruzi infection interferes with neurogenesis and gliogenesis of embryos of infected mice females, and whether RSV would be able to avoid or minimize these changes caused by CD. RSV is a polyphenol found in grapes and widely studied for its neuroprotective and antioxidant properties. In addition, we investigated the role caused by the parasite during congenital infection and CNS development. Embryos and their brains were PCR-positive for T. cruzi. For this study, NPCs obtained from telencephalon of infected and uninfected embryos and were cultured in presence of resveratrol for forming neurospheres. The results demonstrated that the congenital transmission of T. cruzi influences CNS formation and neural fate, decreasing the number of neuroespheres and causing an elongation in the phases of the cell cycle. In addition, the parasite promoted an increase in neugliogenesis. Resveratrol was neuroprotective and prevented negative effects of the infection. Thus, we suggest the use of resveratrol as a therapeutic target for the treatment of neuroinflammation or as neuroprotective agent during Chagas disease, as it improves gliogenesis and restores neural migration.