Molecular genetics reveal that silvatic Rhodnius prolixus do colonise rural houses.
Molecular genetics reveal that silvatic Rhodnius prolixus do colonise rural houses.
复制标题
DOI：
10.1371/journal.pntd.0000210
复制
发表时间：
2008-04-02
影响因子：
3.8
通讯作者：
Miles MA
中科院分区：
文献类型：
--
作者：
Fitzpatrick S;Feliciangeli MD;Sanchez-Martin MJ;Monteiro FA;Miles MA
Rhodnius prolixus是委内瑞拉查加斯病的主要媒介。在这里，尽管进行了40年的病媒控制，但质量差的农村住房的家庭虫害仍然存在。这与南美洲南锥体区域形成鲜明对比，在该区域，主要病媒-致病锥蝽已在大面积上被消灭。森林种群的R. prolixus可能解释了控制困难。然而，围绕silvatic R. prolixus：有人认为所有的森林种群实际上都是Rhodnius robustus，一个流行病学上重要性较小的相关物种。在这里，我们调查，通过直接测序（mtcytb，D2）和微卫星分析，1）的身份，林化Rhodnius和2）是否林化种群的Rhodnius从国内人口分离。直接测序证实了R.在棕榈树中发现了多枝虫，森林昆虫可以在房屋中定居，房屋和棕榈树标本共有7个cytb单倍型。此外，在R. robustus和R. prolixus，表明以前的杂交事件。使用10个多态性微卫星位点揭示了缺乏遗传结构之间的森林和国内生态区（非显着的FST值），这是不受限制的基因流的指示。分析表明，silvatic R. prolixus对委内瑞拉南美锥虫病的控制构成了毫无疑问的威胁。设计改进的控制策略对于成功的长期控制至关重要，可以包括修改喷洒和监测方法，以及住房改善。查加斯病是由吸血昆虫（锥蝽）传播的，这些昆虫在质量差的房屋中定居。疾病控制主要依靠向住宅喷洒残留杀虫剂来杀灭室内害虫。在委内瑞拉，尽管进行了40年的运动，但持续控制已被证明是困难的。被认为是委内瑞拉的主要媒介，Rhodnius prolixus也可能侵染棕榈树，并可能反复从棕榈树上传播房屋。一个复杂的问题是，一个形态相似的物种，R。粗壮虫也寄生在手掌上，但在医学上的重要性较小。因此，棕榈虫的真实身份及其在疾病传播中的重要性存在混淆。我们采用了两种分子方法（细胞色素B基因的DNA测序和微卫星分析）收集在委内瑞拉的锥蝽，使我们能够明确地确定棕榈居住Rhodnius的物种，并建立他们的作用，在维护房子的侵扰。我们证明了R.这表明，棕榈树中确实存在南美锥虫，这种森林种群可以在房屋中定居，对委内瑞拉成功控制南美锥虫病构成威胁。这一发现解决了一个长期存在的具有重要流行病学意义的争议。这也是应用分子流行病学正确鉴定病媒和成功控制疾病的一个例子。
Rhodnius prolixus is the main vector of Chagas disease in Venezuela. Here, domestic infestations of poor quality rural housing have persisted despite four decades of vector control. This is in contrast to the Southern Cone region of South America, where the main vector, Triatoma infestans, has been eliminated over large areas. The repeated colonisation of houses by silvatic populations of R. prolixus potentially explains the control difficulties. However, controversy surrounds the existence of silvatic R. prolixus: it has been suggested that all silvatic populations are in fact Rhodnius robustus, a related species of minor epidemiological importance. Here we investigate, by direct sequencing (mtcytb, D2) and by microsatellite analysis, 1) the identity of silvatic Rhodnius and 2) whether silvatic populations of Rhodnius are isolated from domestic populations. Direct sequencing confirmed the presence of R. prolixus in palms and that silvatic bugs can colonise houses, with house and palm specimens sharing seven cytb haplotypes. Additionally, mitochondrial introgression was detected between R. robustus and R. prolixus, indicating a previous hybridisation event. The use of ten polymorphic microsatellite loci revealed a lack of genetic structure between silvatic and domestic ecotopes (non-significant FST values), which is indicative of unrestricted gene flow. Our analyses demonstrate that silvatic R. prolixus presents an unquestionable threat to the control of Chagas disease in Venezuela. The design of improved control strategies is essential for successful long term control and could include modified spraying and surveillance practices, together with housing improvements. Chagas disease is spread by blood-feeding insects (triatomine bugs) that colonise poor-quality houses. Disease control relies primarily on killing domestic bugs by spraying dwellings with residual insecticide. In Venezuela, sustained control has proved difficult despite four decades of campaigns. Considered the main vector in Venezuela, the bug Rhodnius prolixus may also infest palm trees and might repeatedly recolonise houses from palms. A complication is that a morphologically similar species, R. robustus, also infests palms but is of minor medical importance. Therefore, confusion exists as to the true identity of palm bugs and their importance in disease transmission. We applied two molecular methods (sequencing DNA of the cytochrome b gene, and analysing microsatellites) to triatomines collected in Venezuela so that we could identify unequivocally the species of palm-dwelling Rhodnius and establish their role in maintaining house infestations. We demonstrated that R. prolixus is indeed present in palms, and that such silvatic populations can colonise houses and are a threat to the successful control of Chagas disease in Venezuela. This finding resolves a longstanding controversy of fundamental epidemiological importance. It is also an example of the application of molecular epidemiology to correct vector identification and successful disease control.
登录
查看更多内容
影响因子：
9.6
作者：
Guhl, F;Restrepo, M;Davies, CR
通讯作者：
Davies, CR
影响因子：
1.9
作者：
HARRY, M;GALINDEZ, I;CARIOU, ML
通讯作者：
CARIOU, ML
影响因子：
4.9
作者：
HUGHES, CR;QUELLER, DC
通讯作者：
QUELLER, DC
影响因子：
2.1
作者：
Garcia, BA;Powell, JR
通讯作者：
Powell, JR
DOI：
10.1266/jjg.69.233
发表时间：
1994-06-01
期刊：
JAPANESE JOURNAL OF GENETICS
影响因子：
--
作者：
HARRY, M
通讯作者：
HARRY, M