Fundação Oswaldo Cruz-Fiocruz, Instituto René Rachou, Grupo de Comportamento de Vetores e Interação com Patógenos, Belo Horizonte, MG, Brasil.
Fundação Oswaldo Cruz-Fiocruz, Instituto René Rachou, Grupo de Biotecnologia Aplicada ao Estudo de Patógenos, Belo Horizonte, MG, Brasil.
Mem Inst Oswaldo Cruz. 2024 Nov 22;119:e240138. doi: 10.1590/0074-02760240138. eCollection 2024.
Trypanosoma rangeli is a haemoflagellate parasite that infects triatomine bugs and mammals in South and Central America. Trypanosoma cruzi, the etiological agent of Chagas disease, has a partially overlapping geographical distribution with T. rangeli, that leads to mixed human infections and cross-reactivity in immunodiagnosis. Although T. rangeli can be detected long after mammal infection, its multiplicative forms have not yet been described.
To enhance our understanding of T. rangeli development in mammals, this study assessed various infection parameters in mice over time.
The parasitaemia, body temperature, and weight of Swiss Webster mice were monitored over 120 days after exposing them to the bites of Rhodnius prolixus nymphs containing metacyclic trypomastigotes in their salivary glands. On day 132 post-infection, spleens and mesenteric lymph nodes were analysed for T. rangeli DNA using polymerase chain reaction (PCR) and quantitative PCR (qPCR).
Parasites were detectable in mice blood since day 2 post-infection, detection peaking on day 5 and becoming undetectable by day 120. PCR and qPCR detected T. rangeli DNA in the spleens and mesenteric lymph nodes of infected mice. Infected mice showed higher body temperatures and a slower weight gain over time compared to controls.
The study confirmed that T. rangeli establishes a persistent infection in mice, detectable in lymphoid organs long after parasites had disappeared from blood. In addition, infected mice exhibited physiological changes, suggesting potential subclinical effects. These findings highlight the need for further studies on the immune response and potential impacts of T. rangeli infection in mammalian hosts.
兰氏锥虫是一种血鞭毛原生动物寄生虫，感染中南美洲的三锥虫和哺乳动物。克氏锥虫是恰加斯病的病原体，与兰氏锥虫有部分重叠的地理分布，导致人类混合感染和免疫诊断中的交叉反应。虽然在哺乳动物感染后很长时间都可以检测到兰氏锥虫，但它的增殖形式尚未被描述。
为了更深入地了解兰氏锥虫在哺乳动物中的发育，本研究随时间评估了感染小鼠的各种感染参数。
将瑞士 Webster 小鼠暴露于含有唾液腺中循环期锥鞭毛体的 Rhodnius prolixus 若虫叮咬下，监测其在 120 天内的寄生虫血症、体温和体重。在感染后第 132 天，使用聚合酶链反应（PCR）和定量 PCR（qPCR）分析脾和肠系膜淋巴结中的兰氏锥虫 DNA。
自感染后第 2 天起，在小鼠血液中即可检测到寄生虫，第 5 天达到高峰，到第 120 天则无法检测到。PCR 和 qPCR 检测到感染小鼠的脾和肠系膜淋巴结中有兰氏锥虫 DNA。与对照组相比，感染的小鼠体温升高，体重增加缓慢。
本研究证实兰氏锥虫在小鼠中建立了持续性感染，在寄生虫从血液中消失很久后仍可在淋巴器官中检测到。此外，感染的小鼠表现出生理变化，表明可能存在亚临床影响。这些发现强调了需要进一步研究兰氏锥虫感染对哺乳动物宿主的免疫反应和潜在影响。
