SUMMARY: Leishmaniasis is a complex of zoonotic diseases caused by parasites of the genus Leishmania, which can develop in domestic as well as wild animals and humans throughout the world. Currently, this disease is spreading in rural and urban areas of non-endemic regions in Brazil. Recently, bats have gained epidemiological significance in leishmaniasis due to its close relationship with human settlements. In this study, we investigated the presence of Leishmania spp. DNA in blood samples from 448 bats belonging to four families representing 20 species that were captured in the Triangulo Mineiro and Alto Paranaiba areas of Minas Gerais State (non-endemic areas for leishmaniasis), Brazil. Leishmania spp. DNA was detected in 8·0% of the blood samples, 41·6% of which were Leishmania infantum, 38·9% Leishmania amazonensis and 19·4% Leishmania braziliensis. No positive correlation was found between Leishmania spp. and bat food source. The species with more infection rates were the insectivorous bats Eumops perotis; 22·2% (4/18) of which tested positive for Leishmania DNA. The presence of Leishmania in the bat blood samples, as observed in this study, represents epidemiological importance due to the absence of Leishmaniasis cases in the region.

This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with liveT. gondiiand identified Th17 (CD4⁺) and Tc17 (CD8⁺) cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10); immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4⁺and CD8⁺T cells expressing IL-17. The addition of tachyzoites to cell cultures induced the synthesis of IL-5, IL-10, and TNF-αby cells from seronegative parturient women and of IL-5 and IL-10 by cells from seropositive, nonpregnant women. We observed a lower level of IL-17-expressing CD4⁺and CD8⁺T lymphocytes in cultures of cells from seronegative and seropositive parturient and nonpregnant women that were stimulated with tachyzoites, whereas analysis of the CD4⁺and CD8⁺T cell populations showed a higher level of CD4⁺T cells compared with CD8⁺T cells. These results suggest that the cytokine pattern and IL-17-expressing CD4⁺and CD8⁺T lymphocytes may have important roles in the inflammatory response toT. gondii, thus contributing to the maintenance of pregnancy and control of parasite invasion and replication.

INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA). RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6) to 10(7) parasites/mL) and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.