Leishmania parasites are a group of kinetoplastid pathogens that cause a variety of clinical forms while maintaining cell communication by secreting extracellular vesicles. Emerging technologies have been adapted for the studies of Leishmania-host-cell interactions to enable broad scale analysis of parasite extracellular vesicles. Leishmania extracellular vesicles (LEVS) are naturally released spheroidal nanoparticles of polydispersed suspensions surrounded by a lipid layer of membrane. Although LEVs have increasingly gained in importance, much is still unexplained, including bioavailability and function in the complex molecular mechanisms of pathogenesis. Considering the importance of LEVs in the parasite-host interaction and in the parasite-parasite relationships emerged during evolution, the current review aims at giving an overview of Leishmania summarizing knowledge and formulating guidelines for LEVs research. In the end, we report, direct methods for specific isolation of LEVs from promastigotes and amastigotes culture supernatant suitable for a range of different downstream applications increasing the compatibility and reproducibility to establish optimal and comparable isolation conditions and full LEVs characterization, and crucial immunomodulatory events triggered by this important group of parasites.

Rotaviruses are highly infectious and typically transmitted by fecal-oral route via in the tropics and leading the cause of diarrheal deaths in children of developing countries, besides causing significant economic impacts like neonatal disease agents of domestic animals. This present report aims to present the clinical and diagnostic findings of two confirmed cases of rotavirus (RV) infection in orphaned Leopardus tigrinus (Schreber, 1775) and Leopardus pardalis (Linnaeus, 1758), the first register of the infection by group A rotavirus in these species. Both felids were rescued in the Pará State Amazon Brazil by the IBAMA (the Brazilian Institute of Environment and Renewable Natural Resources), and treated by veterinarians into intensive care ward in a public Environmental Park of Belém city. After the adaptation period to the quarantine, these animals showed non-specific symptoms of acute fulminant gastroenteritis. Rotavirus group A antigen was identified in blood and faecal samples of L. tigrinus analyzed by immunochromatography (ICG) and immunoassay methods (ELISA) at the Virology Laboratory of the Institute Evandro Chagas. The animals died within few days during the clinical exacerbation unresponsive to current treatment, its necropsies and histopathological analysis were performed in the Laboratory of Veterinary Pathology of the Federal Rural University of Amazonia (UFRA). Despite the compatible pathologic findings of rotavirus infection in both animals, the atypical hemorrhagic character was a curious finding, considering the presumed etiology.