Universidade Federal do Maranhão, Programa de Pós-Graduação em Ciências da Saúde, São Luís, Maranhão, Brazil.
Universidade Federal do Maranhão, Departamento de Biologia, Laboratório de Genética e Biologia Molecular, São Luís, Maranhão, Brazil.
Rev Inst Med Trop Sao Paulo. 2021 Dec 6;63:e81. doi: 10.1590/S1678-9946202163081. eCollection 2021.
Lutzomyia longipalpis is the natural vector of Leishmania (Leishmania) infantum, but it is also permissive for several Leishmania species that are related to cutaneous leishmaniasis (CL). Maranhao State (Northeast of Brazil) is endemic for CL and has the highest number of cases of diffuse cutaneous leishmaniasis (DCL) in the country. It is a rare disease associated with a defective immune response mainly caused by L. (L.) amazonensis. Additionally, the number of immunosuppressed patients infected with the etiologic agents of CL has increased, including regions in which the main vectors of CL are rare. Therefore, we investigated whether Lu. longipalpis is able to transmit L. (L.) amazonensis to uninfected and immunosuppressed mice, resulting in CL. For that, 291 sand flies took an initial blood meal in mice infected with L. (L.) amazonensis. Of these, 17 underwent a second feeding on uninfected and immunosuppressed mice (of which 58.8% were also positive for Leishmania according to data on the dissection of the intestine). After 27 days of infection, these mice exhibited leishmaniotic lesions. The occurrence of parasites on the animal's skin was confirmed by limiting dilution and immunohistopathological analyses. Parasite DNA was also detected in paw lesions and inguinal lymph nodes. DNA sequencing confirmed the Leishmania species in insects and mice. The results confirmed the ability of Lu. longipalpis to become infected and experimentally transmit L. (L.) amazonensis to immunosuppressed rodents, resulting in leishmaniotic lesions. Our data open perspectives for the potential role of Lu. longipalpis in the epidemiology of urban cutaneous leishmaniasis, especially in immunosuppressed patients.
长刺伊蚊是利什曼原虫（利什曼原虫）的天然载体，但它也允许几种与皮肤利什曼病（CL）相关的利什曼原虫。马拉尼昂州（巴西东北部）是 CL 的地方病，也是该国弥漫性皮肤利什曼病（DCL）病例最多的州。它是一种罕见的疾病，与主要由 L.（L.）引起的免疫缺陷反应有关亚马逊。此外，感染 CL 病原体的免疫抑制患者数量有所增加，包括 CL 主要载体罕见的地区。因此，我们调查了长刺伊蚊是否能够将 L.（L.）传播给未感染和免疫抑制的小鼠，从而导致 CL。为此，291 只沙蝇在感染 L.（L.）的小鼠中进行了初始血液摄食。其中，17 只在未感染和免疫抑制的小鼠（根据对肠道解剖的数据分析，其中 58.8%也为利什曼阳性）上进行了第二次进食。感染 27 天后，这些小鼠出现了利什曼病变。通过限制稀释和免疫组织病理学分析确认了动物皮肤上寄生虫的存在。在爪部病变和腹股沟淋巴结中也检测到寄生虫 DNA。DNA 测序证实了昆虫和小鼠中的利什曼物种。结果证实了长刺伊蚊能够感染并在实验中向免疫抑制的啮齿动物传播 L.（L.），从而导致利什曼病变。我们的数据为长刺伊蚊在城市皮肤利什曼病的流行病学中可能发挥的作用开辟了前景，特别是在免疫抑制患者中。
