Universidade Federal do Rio Grande, Área Acadêmica do Hospital Universitário, Programa de Pós-Graduação em Ciências da Saúde, Laboratório de Parasitologia, Rio Grande, Rio Grande do Sul, Brazil.
Universidade Federal de Pelotas, Departamento de Microbiologia e Parasitologia, Programa de Pós-Graduação em Parasitologia, Pelotas, Rio Grande do Sul, Brazil.
Rev Inst Med Trop Sao Paulo. 2021 Jan 29;63:e9. doi: 10.1590/S1678-9946202163009. eCollection 2021.
Human toxocariasis consists of chronic tissue parasitosis that is difficult to treat and control. This study aimed to evaluate the action of the probiotic Lactobacillus acidophilus ATCC 4356 on larvae of Toxocara canis and the effect of IFN-γ cytokine on parasite-host in vivo (1.109 CFU) and in vitro (1.106, 1.107, 1.108, 1.109 CFU) interactions. Four groups of six BALB/c mice were formed: G1 - L. acidophilus supplementation and T. canis infection; G2 - T. canis infection; G3 - L. acidophilus supplementation; and G4 - PBS administration. Mice were intragastrically suplemented with probiotics for 15 days before inoculation and 48 h after inoculation with 100 T. canis eggs. The inoculation of T. canis was also perfomed intragastrically. The recovery of larvae took place through digestion of liver and lung tissues; the evaluation of IFN-γ gene transcription in leukocytes was performed by qPCR. The in vitro test consisted of incubating the probiotic with T. canis larvae. The supplementation of probiotics produced a reduction of 57.7% (p = 0.025) in the intensity of infection of T. canis larvae in mice, whereas in the in vitro test, there was no larvicidal effect. In addition, a decrease in the IFN-γ gene transcription was observed in both, T. canis-infected and uninfected mice, regardless of whether or not they received supplementation. The probiotic L. acidophilus ATCC 4356 reduced T. canis infection intensity in mice, however, the probiotic did not have a direct effect on larvae, demonstrating the need of interaction with the host for the beneficial effect of the probiotic to occur. Yet, the proinflammatory cytokine IFN-γ did not apparently contributed to the observed beneficial effect of probiotics.
人体弓蛔虫病由慢性组织寄生虫病引起，难以治疗和控制。本研究旨在评估益生菌嗜酸乳杆菌 ATCC 4356 对犬弓蛔虫幼虫的作用，以及 IFN-γ 细胞因子对寄生虫-宿主体内（1.109 CFU）和体外（1.106、1.107、1.108、1.109 CFU）相互作用的影响。将 6 只 BALB/c 小鼠分为四组：G1-嗜酸乳杆菌补充和犬弓蛔虫感染；G2-犬弓蛔虫感染；G3-嗜酸乳杆菌补充；G4-PBS 给药。在接种前 15 天和接种后 48 小时，用益生菌灌胃补充小鼠。犬弓蛔虫的接种也是通过胃内接种进行的。通过消化肝脏和肺组织进行幼虫回收；通过 qPCR 检测白细胞中 IFN-γ 基因转录的评估。体外试验包括将益生菌与犬弓蛔虫幼虫孵育。益生菌的补充使犬弓蛔虫幼虫在小鼠中的感染强度降低了 57.7%（p=0.025），而在体外试验中，没有杀幼虫作用。此外，无论是否接受补充，感染和未感染犬弓蛔虫的小鼠 IFN-γ 基因转录均下降。益生菌嗜酸乳杆菌 ATCC 4356 降低了小鼠感染犬弓蛔虫的强度，但益生菌对幼虫没有直接作用，表明需要与宿主相互作用才能发挥益生菌的有益作用。然而，促炎细胞因子 IFN-γ 似乎没有明显促进益生菌的观察到的有益作用。
