Pesquisa de parasitas dos gêneros trypanossoma e leishmania em pequenos mamíferos no município de São Luís - Maranhão, Brasil

Abstract

Species of the genera Trypanosoma and Leishmania parasitize vertebrates, with life cycles alternating between vertebrates (mammals, fish, amphibians, reptiles and birds, in the case of parasites of the genus Trypanosoma, and the species of Leishmania, mammals of the Old and New World) and invertebrates (triatomines and blood-sucking dipterans for Trypanosoma and blood-sucking dipterans for Leishmania) Considering the importance of small wild mammals as reservoirs of these parasites, the objective was to carry out the diagnosis of Trypanosoma and Leishmania in these hosts in the Environmental Protection Area (APA) of Itaqui-Bacanga , APA do Maracanã and at the Paulo VI campus of the State University of Maranhão/UEMA in the municipality of São Luís-Maranhão. Eleven collections were carried out, four in the Maracanã APA (January, June, September and December 2018); three in the Itaqui – Bacanga Area (December 2020, July and December 2021) and four in the Paulo VI campus of UEMA (May, August and October 2021), and 36 animals were captured. The animals were captured using Shermman and Tomahawk traps. The animals were anesthetized and some specimens euthanized for collection of biological samples. Blood samples were collected (cardiac puncture or caudal vein) for blood culture in biphasic culture medium (BAB/LIT) in duplicate per animal. Blood smears were prepared, in triplicate, to investigate the parasites, and these blood samples were used for molecular diagnosis. Blood samples and liver and spleen fragments were collected from the euthanized animals for DNA extraction and subsequent molecular analysis, totaling 81 samples. DNA extraction from the samples was performed using the GeneJet Genomic DNA Purification Kit (Thermo Fisher Scientific®) and the V7V8 genes of SSU rRNA, gGAPDH and Cathepsin L-like were used for amplification. All smears and blood cultures were negative, however in the molecular analysis for the V7V8 gene, eight samples were positive, from six animals, three of the species Didelphis marsupialis, from APA do Maracanã, and one Rattus rattus, two Rattus sp. from the Itaqui-Bacanga area; and for the gene gGAPDH, nine samples from seven animals were positive, three of which Didelphis marsupialis (APA do Maracanã), one Rattus novergicus, one Rattus rattus and two Rattus sp. (APA of Itaqui- Bacanga). There was no positivity in the molecular analysis for the Cathepsin L-like gene. It is important to continue the monitoring of small wild mammals in these areas, since the results confirm the presence of Trypanosoma, since in endemic areas rodents and marsupials are reservoirs of these species, contributing to the maintenance of the wild and peridomestic cycle