Identificação molecular e avaliação clínica, bioquímica e hematológica em equinos e caninos com Leishmaniose

Abstract

Leishmaniosis is a vector-borne infectious parasitic disease, caused by Leishmania protozoa. It affects several vertebrate species, being the dog as the main urban reservoir. Equines can also be infected, especially when in contact with reservoirs or vectors in endemic areas. In view of the epidemiological situation of visceral leishmaniosis (VL) in Uruguaiana, western border of Rio Grande do Sul, as the transmission area, this study was carried out to perform molecular identification of Leishmania sp. in canines and equines, as well as to evaluate clinical signs, haematological, biochemical and oxidative stress disorders of infected animals. A total of 127 animals (98 horses and 29 canines) of both genders with different breeds and ages, in the period ranging from November 2016 to September 2017, present either in urban and suburbs areas of the municipality, participated in the experiment. Anamnesis was performed and the animals underwent clinical evaluation and peripheral blood collection. The molecular diagnosis was performed using Polymerase Chain Reaction (PCR) with DNA isolated from blood samples, with two primer pairs: RV1 / RV2 - which hybridizes to kDNA LT1 region (amplicon of 145 bp); and the L5.8SR / LITSV primers - specific for the 750 bp ribosomal DNA ITS2 region. These amplicons had their sequences determined and used for phylogenetic inference. Haematological and biochemical changes were assessed with hematology analyzer (Sysmex KX-21N), differential smear slide count and biochemical analyzer (Wiener CM 200) with commercial Bioclin - Quibasa kits. Lipid peroxidation and protein carbonylation techniques were employed for oxidative damage analysis. Molecular diagnosis identified 14 horses and 15 canines infected by Leishmania spp.. From these, the amplicons obtained from 11 horses and 14 canines were determined. Molecular characterization revealed similarity with: Leishmania infantum / Leishmania chagasi, Leishmania donovani and Leishmania major. The main clinical and haematological disorders were: skin lesions, nodules, lymphadenopathy, red blood cells and hematocrit decrease, and increase of urea in horses. In dogs, there were a decrease in the amount of red blood cells and lymphocytosis. No changes in oxidative stress markers were observed. This work pioneered the identification and characterization of Leishmania spp. circulating in the western border region of Rio Grande do Sul, after identifying this area as the transmission area for VL. In addition, investigations into the Leishmania infection and the evaluation of clinical, hematological, biochemical and oxidative stress alterations in horses from areas with CVL in the municipality were initiated. Research should be intensified to recognize the different hosts and their clinical alterations, as well as to improve the identification and characterization techniques of the infecting species in the region, which represents fundamental epidemiological importance considering the location, Brazil / Uruguay / Argentina, in order to re-evaluate the measures of control and prevention of leishmaniosis.