First record of Trypanosoma evansi DNA in Dichelacera alcicornis and Dichelacera januarii (Diptera: Tabanidae) flies in South America.

BACKGROUND: Trypanosoma evansi infects a large number of wild and domestic animals and causes a spoliative disease known as surra. It is mechanically transmitted, mainly by biting flies of the genera Tabanus and Stomoxys. The detection of T. evansi DNA in the feeding apparatus of Dichelacera alcicornis and Dichelacera januarii from South America is reported, to the best of our knowledge, for the first time. METHODS: Tabanids were collected weekly from February 2018 to February 2019 from two sites. The feeding apparatus was removed and DNA extraction, polymerase chain reaction and sequencing were performed. RESULTS: A 205-base pair fragment of the variant surface protein RoTat 1.2 gene, confirmed by DNA sequencing, was amplified from the feeding apparatus of D. alcicornis and D. januarii. CONCLUSIONS: This is, to the best of our knowledge, the first record of T. evansi DNA in South American tabanids.

Trypanosoma evansi secretome carries potential biomarkers for Surra diagnosis.

Trypanosoma evansi is a parasite that is phylogenetically close to Trypanosoma brucei and is the causative agent of a disease known as surra. Surra is responsible for a high mortality rate in livestock and large economic losses in the Americas, Africa, and Asia. This work aimed to analyze in vitro secreted proteins from T. evansi and identify potential treatment and diagnostic biomarkers for surra diagnosis. Two groups were used. In one group the parasites were purified using a DEAE-Cellulose column and maintained in a secretion medium while in the other group the parasites were not purified. Each group was further divided to be maintained at either 37 °C or 27 °C. We identified 246 proteins through mass spectrometry and found that the temperature appears to modulate protein secretion. We found minimal variations in the protein pools from pure and non-purified sets. We observed an emphasis on proteins associated to vesicles, glycolysis, and cellular homeostasis through the enrichment of GO. Also, we found that most secretome proteins share homologous proteins with T. b. brucei, T. b. gambiense, T. vivax, T. equiperdum, and T. b. rhodesiense secretome but unique T. evansi epitopes with potential biomarkers for surra diagnosis were detected. SIGNIFICANCE: Trypanosoma evansi is a parasite of African origin that is phylogenetically close to Trypanosoma brucei. As with other trypanosomatids and blood parasites, its infection causes non-pathognomonic symptoms, which makes its diagnosis difficult. One great problem is the fact that no diagnostic test differentiates between Trypanosoma equiperdum and T. evansi, which is a problem in South America and Asia, and Africa. Thus, it is urgent to study the biochemistry of the parasite to discover proteins that can be used for differential diagnosis or be possible therapeutic targets. In addition, the study of the secretome can point out proteins that are used by the parasite in its interactions with the host, helping to understand the progression of the disease.