Department of Biochemistry, Biosciences Center, Universidade Federal do Rio Grande do Norte, Av. Sen. Salgado Filho, 3000, Natal, RN, Brazil, 59078.
Department of Biology and Genetics, Biosciences Center, Universidade Federal do Rio Grande do Norte, Av. Sen. Salgado Filho, 3000, Natal, RN, Brazil, 59078.
J Med Entomol. 2014 Jan;51(1):237-44. doi: 10.1603/me12131.
Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in Brazil, is spread mostly by the bite of the sand fly Lutzomyia longipalpis (Lutz & Neiva). We trapped sand flies in endemic neighborhoods near Natal, Brazil, where cases of human and dog VL were documented. Amplification of species-specific cytochrome b (Cyt b) genes by polymerase chain reaction revealed that sand flies from rural and periurban areas harbored blood from different sources. The most common source ofbloodmeal was human, but blood from dog, chicken, and armadillo was also present. We tested the preference for a source of bloodmeal experimentally by feeding L. longipalpis F1 with blood from different animals. There were significant differences between the proportion of flies engorged and number of eggs laid among flies fed on different sources, varying from 8.4 to 19 (P < 0.0001). Blood from guinea pig or horse was best to support sand fly oviposition, but human blood also supported sand fly oviposition well. No sand flies fed on cats, and sand flies feeding on the opossum Monodelphis domestica Wagner produced no eggs. These data support the hypothesis that L. longipalpis is an eclectic feeder, and humans are an important source of blood for this sand fly species in periurban areas of Brazil.
在巴西，引起内脏利什曼病（VL）的病原体是婴儿利什曼原虫（Leishmania infantum），主要通过沙蝇（Lutzomyia longipalpis）（Lutz & Neiva）的叮咬传播。我们在巴西纳塔尔（Natal）附近的流行地区捕获了沙蝇，那里有人类和狗患 VL 的病例记录。通过聚合酶链反应（PCR）扩增物种特异性细胞色素 b（Cyt b）基因表明，来自农村和城郊地区的沙蝇携带来自不同来源的血液。最常见的血液来源是人类，但也存在狗、鸡和犰狳的血液。我们通过用不同动物的血液喂养 L. longipalpis F1 来实验测试对血源的偏好。在不同来源的血液喂养的苍蝇中，饱食的苍蝇比例和产卵数量之间存在显著差异，范围从 8.4 到 19（P < 0.0001）。来自豚鼠或马的血液最有利于支持沙蝇产卵，但人类血液也能很好地支持沙蝇产卵。没有沙蝇吸食猫的血液，而吸食负鼠（Monodelphis domestica Wagner）的沙蝇则没有产卵。这些数据支持了 L. longipalpis 是一种杂食性昆虫的假设，并且在巴西城郊地区，人类是这种沙蝇物种重要的血液来源。
