Pacanaro Carina P, Dias Sílvia R, Serafim Luciana R, Costa Mariana P, Aguilar Edenil, Paes Paulo R, Alvarez-Leite Jacqueline I, Rabelo Elida M
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Faculdade Estácio de Sá de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
PLoS Negl Trop Dis. 2014 Sep 25;8(9):e3184. doi: 10.1371/journal.pntd.0003184. eCollection 2014 Sep.
Hookworms infect millions of people worldwide and can cause severe clinical symptoms in their hosts. Prospective cohort studies in Brazil show high rates of hookworm reinfection in malnourished children compared to well-nourished children, despite previous treatment. Additionally, soil-transmitted helminth (STH) infections can worsen the nutritional status of affected populations. Therefore, this study aims to clarify the effects of host malnutrition during Ancylostoma ceylanicum infection and how this infection affects host physiological parameters using a hamster model.
METHODOLOGY/PRINCIPAL FINDINGS: Hamsters were divided into four experimental groups: normal diet or low-protein diet (also referred to as "malnourished") and A. ceylanicum infection or no infection. More severe pathogenesis was observed in the infected malnourished group, as demonstrated by significant decreases in the hemoglobin concentration, erythrocyte number and packed-cell volume compared to the non-infected malnourished group. Greater numbers of adult parasites and eggs were observed in the malnourished group compared to the control group; however, the oviposition rate was lower in the malnourished group. In general, greater values of total lipids were observed in malnourished animals compared to control animals, including lipids excreted in the stool.
In this work, we have demonstrated that animals fed an isocaloric low-protein diet presented more severe pathogenesis when infected with A. ceylanicum. The increased lipid concentration in the liver and blood is related to the conversion of the excess carbohydrate into fatty acids that increase the concentration of triglycerides in general. Triglycerides were excreted in the feces, indicating that infection associated with malnutrition caused a greater loss of these molecules for this group of animals and confirming the hypothesis that both nutrition and infection are responsible for the malabsorption syndrome. Taken together, the results found in this work confirm the hypothesis that the nutritional condition of the host greatly influences the course of the infection.
钩虫感染全球数百万人，并可在其宿主中引起严重的临床症状。巴西的前瞻性队列研究表明，与营养良好的儿童相比，营养不良的儿童尽管先前接受过治疗，但钩虫再感染率仍很高。此外，土壤传播的蠕虫（STH）感染会使受影响人群的营养状况恶化。因此，本研究旨在使用仓鼠模型阐明宿主营养不良在锡兰钩虫感染期间的影响，以及这种感染如何影响宿主生理参数。
方法/主要发现：仓鼠被分为四个实验组：正常饮食或低蛋白饮食（也称为“营养不良”）以及感染锡兰钩虫或未感染。与未感染的营养不良组相比，感染的营养不良组观察到更严重的发病机制，表现为血红蛋白浓度、红细胞数量和血细胞比容显著降低。与对照组相比，营养不良组观察到更多的成虫和虫卵；然而，营养不良组的产卵率较低。一般来说，与对照动物相比，营养不良动物的总脂质值更高，包括粪便中排出的脂质。
在这项研究中，我们证明了喂食等热量低蛋白饮食的动物在感染锡兰钩虫时表现出更严重的发病机制。肝脏和血液中脂质浓度的增加与多余碳水化合物转化为脂肪酸有关，总体上增加了甘油三酯的浓度。甘油三酯通过粪便排出，表明与营养不良相关的感染导致这组动物这些分子的损失更大，并证实了营养和感染均导致吸收不良综合征的假设。综上所述，这项研究的结果证实了宿主的营养状况极大地影响感染进程这一假设。
