Microsatellite variation revealed panmictic pattern for Triatoma brasiliensis (Triatominae: Reduviidae) in rural northeastern Brazil: the control measures implications

Abstract

Background Triatoma brasiliensis Neiva, 1911 is the main vector of Trypanosoma cruzi in the caatinga of Northeastern Brazil. Despite of its epidemiological relevance, there are few studies on its genetic variability. Using microsatellite markers, we characterized the variability and dynamics of infestation and reinfestation of T. brasiliensis after residual insecticide spraying in five surveys conducted in a well-defined rural area located in the municipality of Tauá, Ceará, between 2009 and 2015. We evaluated: (1) general variability among local of captures; (2) variability along the time analysis (2009, 2010 and 2015); (3) and reinfestation process. Results On the analysis (1) global and pairwise F ST values suggested absence of clusters among the area. AMOVA indicated that total variation is mainly represented by individual differences. Absence of clustering indicates a panmitic unit, with free gene flow. For (2), Pairwise F ST indicated alterations in the genetic profile of the triatomines along the time. (3) Analysis of the reinfestation process showed that the domiciliary units investigated had different sources of infestation despite of its proximity. Conclusions Observed homogeneity can be explained by the great dispersal capacity of T. brasiliensis , overlapping the different environments. Persistent house infestation in Tauá may be attributed to the occurrence of postspraying residual foci and the invasion of triatomines from their natural habitats.

Experimental Hybrids of the Triatoma brasiliensis Species Complex Show Higher Susceptibility to the Trypanosoma cruzi Infection Than Their Parentals

“…In addition to this, it was suggested more recently that the species' sexual choice is not always conspecific but can increase genetic variability, which emphasizes the importance of better understanding the hybrids' vector competence and capacity [52]. We also want to stress that the parentals, T. b brasiliensis and T. juazeirensis, play a relevant role as vectors of the etiologic agent of Chagas disease in several states of the northeast region of Brazil [27][28][29][30][31][32]36,37,53].…”

“…Triatoma b. brasiliensis is one of the most important triatomine species in northeastern Brazil because of its wide geographic distribution (in five Brazilian states), its high rate of domiciliation, and its spread through natural infection [27,29,31,32]. Moreover, the programs to control Triatoma infestans (Klug, 1834), which was previously considered the main vector in Latin America, were not so effective for T. b. brasiliensis, a native vector, which colonized not just human domiciles but also infested several artificial and natural ecotopes [6,27,[31][32][33][34][35][36][37].…”

Morphological Stasis in Time? A Triatoma brasiliensis brasiliensis Study Using Geometric Morphometrics in the Long Run

“…Triatoma brasiliensis brasiliensis is one of the most important vectors of Chagas disease in the semiarid regions in Brazil [ 6 , 7 , 12 ] and occurs in six states: Ceará, Maranhão, Paraíba, Pernamb uco, Piauí, and Rio Grande do Norte. This species displays eclectic feeding behavior and can inhabit different ecotopes, besides presenting one of the highest rates of T. cruzi infection and high rates of intradomiciliary infestation [ 7 , 8 , 13 , 14 , 15 , 16 , 17 , 18 ]. The epidemiologic importance of T. b. brasiliensis has motivated a variety of studies, placing it as one of the most studied species of triatomines.…”