First report of Trypanosoma evansi A-type from the Ecuadorian Amazon: Phylogenetic and structural analyses of the VSG RoTat1.2 fragment.

The study details the first ever molecular identification of a protozoan parasite, Trypanosoma evansi, in certain regions of the Ecuadorian Amazon, offering analysis on the phylogenetic structure of the VSG RoTat 1.2 fragment.

About Trypanosoma evansi

• The protozoan parasite, Trypanosoma evansi, is part of the Trypanozoon subgenus.
• This parasite infects both domestic and wild animals globally and sometimes even humans.
• Its significance lies in its impact on livestock production, especially in South America where epidemiological studies and molecular analyses remain limited.

Study Overview and Methodology

• Researchers reported the first molecular identification of T. evansi in the Orellana and Sucumbíos provinces of Ecuador.
• The study was conducted using a retrospective biobank approach, decrypting DNA from blood samples of dogs and horses from these regions.
• Three primer sets were used for targeting the internal transcribed spacer 1 (ITS1), expression site-associated genes 6 and 7 (ESAG6/7), and VSG RoTat 1.2.
• The sequences were evaluated at both nucleotide and protein predicted levels.

Research Findings

• The molecular prevalence was found to be 19% (5 out of 26), including one dog from Sucumbíos and one dog plus three horses from Orellana.
• Although the ITS and ESAG phylogenies were inconclusive, the VSG analysis grouped the Ecuadorian genotypes within a unique T. evansi clade.
• This clade was separate from Trypanosoma equiperdum and Trypanosoma brucei.

The VSG Viewpoint

• The amino acid residues of the VSGs of T. evansi isolates were found to be similar, but varied from those of the other two species.
• However, the overall structural preservation of the analyzed portions of the VSGs of Trypanozoon species suggested a maintained membrane protein functionality.

Study Implications

• The findings reveal the silent presence of T. evansi in rural regions of Ecuador, putting animals at risk.
• This highlights the necessity for further investigations of native isolates to ensure the health and well-being of the livestock population.