Laboratorio de Parasitología Experimental, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela.
Laboratorio de Fisiología de la Conducta, Facultad de Medicina, Universidad de Los Andes, Mérida, Venezuela.
Biomedica. 2021 Mar 19;41(1):179-186. doi: 10.7705/biomedica.5394.
Introduction: Belminus ferroae is a triatominae with entomophagous behavior. However, it may occasionally feed on vertebrates. Currently, there is no evidence of natural infection with Trypanosoma cruzi or the occurrence of metacyclogenesis in this species. Objective: To test T. cruzi metacyclogenesis in B. ferroae and the infectivity of their feces or intestinal contents in rodents under laboratory conditions. Materials and methods: Twenty nymphs of B. ferroae were infected with an autochthonous strain of T. cruzi (M/HOM/VE/09/P6). Fecal and urine samples were collected from spontaneous droppings or by compressing the bugs’ abdomens and, eventually, by removing their gut contents, and then examined at 10, 20, 30, 40, 50, and 60 days. We quantified T. cruzi parasitic load, as well as the evolutionary forms in feces, urine, and intestinal contents by Giemsa staining. Similarly, we evaluated the infectivity of T. cruzi metacyclic trypomastigotes in albino mice. Results: The parasitological analysis showed three insects (15%) infected with T. cruzi at 30 (n=1), 40 (n=1), and 50 (n=1) days post-infection. We observed parasitic loads of up to 1.62 x 105 trypanosomes/mm3 and metacyclogenesis percentages between 3.5% and 6.78%. Conclusions: This is the first time that T. cruzi metacyclogenesis is reported in a species of the genus Belminus under laboratory conditions and the infectivity of Belminus’ feces is demonstrated on a vertebrate host.
Belminus ferroae 是一种具有食虫行为的三锥虫。然而，它偶尔也会以脊椎动物为食。目前，尚无证据表明该物种存在天然感染克氏锥虫或发生循环体形成的情况。目的：在实验室条件下，检测 B. ferroae 中的 T. cruzi 循环体形成情况，以及其粪便或肠道内容物对啮齿动物的感染力。材料和方法：用一株源自巴西的 T. cruzi（M/HOM/VE/09/P6）感染 20 只 B. ferroae 若虫。通过自然排便或挤压昆虫腹部，甚至通过移除肠道内容物收集粪便和尿液样本，然后在第 10、20、30、40、50 和 60 天进行检查。我们通过吉姆萨染色来定量粪便、尿液和肠道内容物中的 T. cruzi 寄生虫载量和进化形式。同样，我们评估了 T. cruzi 循环体锥虫在白化小鼠中的感染力。结果：寄生虫学分析显示，在感染后第 30、40 和 50 天，有 3 只昆虫（15%）感染了 T. cruzi（n=1）。我们观察到寄生虫载量高达 1.62 x 105 个锥虫/毫米 3，循环体形成率为 3.5%至 6.78%。结论：这是首次在实验室条件下报告 B. ferroae 属的一种物种中存在 T. cruzi 循环体形成，并且证明了 Belminus 的粪便对脊椎动物宿主具有感染力。
