Belisário Carlota Josefovicz, Pessoa Grasielle Caldas D'Avila, Silva Eduardo Melos, Rosa Aline Cristine Luiz, Ferreira Rafaela Elias, Bedin Cleonara, Wilhelms Tania, de Mello Fernanda, Coutinho Helder Silveira, Fonseca Eduardo Lins Oyama, Dos Santos Roberto Fonseca, Rodrigues Vera Lucia Cortiço Corrêa, Dias João Carlos Pinto, Diotaiuti Liléia
Grupo Triatomíneos, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima 1715, Barro Preto, Belo Horizonte, Minas Gerais, 30.190-002, Brazil.
Laboratório Central de Saúde Pública do Rio Grande do Sul, Instituto de Pesquisas Biológicas, Secretaria de Saúde do Rio Grande do Sul, Avenida Ipiranga 5400, Jardim Botânico, Porto Alegre, Rio Grande Do Sul, 90610-000, Brazil.
Genetica. 2017 Feb;145(1):105-114. doi: 10.1007/s10709-017-9949-y. Epub 2017 Jan 24.
In spite of long-term efforts to eliminate Triatoma infestans (Klug 1834) from Brazil, residual foci still persist in the states of Bahia and Rio Grande do Sul. Data on the genetic variability and structuring of these populations are however lacking. Using nine microsatellite loci, we characterized one residual T. infestans population from Bahia and four from Rio Grande do Sul, and compared them with bugs originally from an older focus in São Paulo; 224 bugs were genotyped. The number of alleles per locus ranged from 5 to 11. Observed and expected heterozygosities per locus ranged, respectively, from 0 to 0.786 and from 0 to 0.764. Significant departures from Hardy-Weinberg equilibrium, mainly due to heterozygote deficits, were detected in all loci and in most populations. Global indices estimated by AMOVA were: Fis was 0.37; Fst was 0.28; and Fit was 0.55; overall indices with p = 0.00 indicated substantial differentiation. Inter-population Fst ranged from 0.118 to 0.562, suggesting strong genetic structuring and little to no gene flow among populations. Intra-population Fis ranged from 0.301 to 0.307. Inbreeding was apparent in all populations except that from Bahia-which might be either linked by gene flow to nearby unsampled populations or part of a relatively large local population. The overall pattern of strong genetic structuring among pyrethroid-susceptible residual T. infestans populations suggests that their persistence is probably due to operational control failures. Detection and elimination of such residual foci is technically feasible and must become a public health priority in Brazil.
尽管巴西长期致力于消灭骚扰锥猎蝽（Klug，1834年），但巴伊亚州和南里奥格兰德州仍存在残余疫源地。然而，关于这些种群的遗传变异性和结构的数据却很缺乏。我们使用9个微卫星位点对来自巴伊亚州的一个残余骚扰锥猎蝽种群和来自南里奥格兰德州的4个种群进行了特征分析，并将它们与最初来自圣保罗一个较旧疫源地的虫子进行了比较；对224只虫子进行了基因分型。每个位点的等位基因数量从5个到11个不等。每个位点观察到的杂合度和预期杂合度分别在0到0.786和0到0.764之间。在所有位点和大多数种群中都检测到显著偏离哈迪-温伯格平衡的情况，主要是由于杂合子缺失。通过分子方差分析（AMOVA）估计的总体指数为：Fis为0.37；Fst为0.28；Fit为0.55；总体指数p = 0.00表明存在显著分化。种群间的Fst在0.118到0.562之间，表明种群间存在强烈的遗传结构，且种群间几乎没有或没有基因流动。种群内的Fis在0.301到0.307之间。除了来自巴伊亚州的种群外，所有种群都存在近亲繁殖现象——这可能是由于基因流动与附近未采样的种群相连，或者是相对较大的当地种群的一部分。拟除虫菊酯敏感的残余骚扰锥猎蝽种群之间强烈的遗传结构总体模式表明，它们的持续存在可能是由于操作控制失败。检测和消除这些残余疫源地在技术上是可行的，必须成为巴西公共卫生的优先事项。
