A darker chromatic variation of Rhodnius pallescens infected by specific genetic groups of Trypanosoma rangeli and Trypanosoma cruzi from Panama

Azael Saldaña,José E Calzada,Vanessa Pineda,Vanessa Vásquez,Nicole L Gottdenker,Ana María Santamaría

doi:10.1186/s13071-018-3004-4

Azael Saldaña, José E Calzada + Show 4 more

Open Access

https://doi.org/10.1186/s13071-018-3004-4

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Abstract

BackgroundRhodnius pallescens, the only species of this genus reported in Panama, has a wide geographical distribution and is associated with most cases of Chagas disease and human infections with Trypanosoma rangeli in this country. Thus far, no phenotypic variants of this triatomine have been registered. Similarly, genotyping of the trypanosomes that infect this vector has only been partially evaluated.ResultsA total of 347 specimens of R. pallescens were collected in Attalea butyracea palm trees located near a mountainous community of the district of Santa Fe, province of Veraguas. Bugs were slightly longer and had a darker coloration compared to that reported for this species. Infection rates for trypanosomes performed with three PCR analyses showed that 41.3% of the adult triatomines were positive for T. cruzi, 52.4% were positive for T. rangeli and 28.6% had mixed T. cruzi/T. rangeli infections. Based on cox2 analysis, TcI was the single T. cruzi discrete typing unit (DTU) detected, and a genetic variant of KP1(-)/lineage C was the only genetic group found for T. rangeli.ConclusionsA darker chromatic variation of R. pallescens predominates in a mountainous region of Panama. These triatomines show high trypanosome infection rates, especially with T. rangeli. Regarding T. rangeli genetic diversity, complementary studies using other molecular markers are necessary to better define its phylogenetic position.

Highlights

Rhodnius pallescens, the only species of this genus reported in Panama, has a wide geographical distribution and is associated with most cases of Chagas disease and human infections with Trypanosoma rangeli in this country
Human infection with Trypanosoma cruzi and/or Trypanosoma rangeli has been reported in different regions of the Republic of Panama [1]
A restriction fragment length polymorphism (RFLP) analysis based on the cytochrome c oxidase subunit 2 gene (PCR/RFLP-cox2) was used for the simultaneous detection and typing of T. rangeli major genetic groups and T. cruzi discrete typing units (DTUs) [10]

Summary

Introduction

The only species of this genus reported in Panama, has a wide geographical distribution and is associated with most cases of Chagas disease and human infections with Trypanosoma rangeli in this country. Trypanosoma rangeli is a parasite not linked to pathological processes in humans [3], but with clinical and epidemiological importance due primarily to its antigenic similarity with T. cruzi [4]. Both trypanosomes are transmitted by triatomine bugs (Reduvidae: Triatominae) of wide distribution in different habitats throughout the country [5]. The principal biotope for R. pallescens is the crown of the “royal palm” (Attalea butyracea), from where it frequently moves to nearby dwellings

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