-The present study was carried out with the objective to evaluate the productive and qualitative characteristics of forages produced in systems of intercropping of corn, brachiaria grass and different leguminous plants. Productivity, bromatological composition and the fermentative profile of the silages from the following treatments were evaluated: corn in exclusive cultivation (CEC); intercropping of corn with brachiaria grass (CB); intercropping of corn, brachiaria grass and Calopogonium mucunoides (CBCal); intercropping of corn, brachiaria grass and Macrotyloma axillare (CBMac); and intercropping of corn, brachiaria grass and Stylozanthes capitata (CBSty). The experimental design utilized was completely randomized. For each type of cultivation, five plots or replications of three linear meters were harvested, and the material was separated. The variables assessed were: dry matter productivity per area; dry matter productivity of corn per area; crude protein production per area and productivity of total digestible nutrients per area. The material originated from the cultures was ensiled, with dry matter between 28 and 32%. After, the material was placed and compacted appropriately in bucket silos. A sample was collected from each replication for determination of the contents of DM, crude protein (CP), ether extract (EE), lignin, neutral and acid detergent fibers (NDF and ADF) and TDN. A fraction of the sample of silages from each treatment was compressed for extraction of the juice and determination of the silage quality. There was difference between the forms of cultivation for the dry matter production per hectare. The CEC with production of 11920.1 kg DM/ha did not differ from CB (8997.41 kg DM/ha) or CBCal (10452.10 kg DM/ha); however, it was superior to CBMac (8429.75 kg DM/ha) and to CBSty (8164.83 kg DM/ha). The contents of DM, CP, NDF, ADF, lignin and TDN did not differ between the silages from the different treatments. All the silages presented good quality with good fermentation patterns.

The lipid mediators, platelet‐activating factor (PAF) and lysophosphatidylcholine (LPC), play relevant pathophysiological roles in Trypanosoma cruzi infection. Several species of LPC, including C18:1 LPC, which mimics the effects of PAF, are synthesized by T. cruzi. The present study identified a receptor in T. cruzi, which was predicted to bind to PAF, and found it to be homologous to members of the progestin and adiponectin family of receptors (PAQRs). We constructed a three‐dimensional model of the T. cruzi PAQR (TcPAQR) and performed molecular docking to predict the interactions of the TcPAQR model with C16:0 PAF and C18:1 LPC. We knocked out T. cruzi PAQR (TcPAQR) gene and confirmed the identity of the expressed protein through immunoblotting and immunofluorescence assays using an anti‐human PAQR antibody. Wild‐type and knockout (KO) parasites were also used to investigate the in vitro cell differentiation and interactions with peritoneal mouse macrophages; TcPAQR KO parasites were unable to react to C16:0 PAF or C18:1 LPC. Our data are highly suggestive that PAF and LPC act through TcPAQR in T. cruzi, triggering its cellular differentiation and ability to infect macrophages.

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We previously showed that L. (Leishmania) amazonensis promastigotes and amastigotes of the PH8 strain generated larger lesions in mice than LV79, and that lesion-derived amastigotes from the two strains differ in their proteomes. We recently reported that PH8 promastigotes are more phagocytized by macrophages. Promastigotes’ membrane-enriched proteomes showed several differences, and samples of each strain clustered based on proteomes. In this paper, we show phenotypic differences between PH8 and LV79 promastigotes that may explain the higher virulence of PH8. We compared in vitro macrophage infections by day 4 (early) and day 6 (late stationary phase) cultures, resistance to complement, and LPG characteristics. PH8 promastigotes showed a higher infectivity and were more resistant to murine complement. LPG was different between the strains, which may influence the interaction with macrophages and survival to complement. We compared the infection of the permissive vector Lutzomyia longipalpis. PH8 was more abundant in the vector’s gut 72 h after feeding, which is a moment where blood digestion is finished and the parasites are exposed to the gut environment. Our results indicate that PH8 promastigotes are more infective, more resistant to complement, and infect the permissive vector more efficiently. These data suggest that PH8 is probably better adapted to the sand fly and more prone to survive in the vertebrate host.

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