Pinheiro Breno Veloso, Noviello Maria de Lourdes Meirelles, Cunha Mariana Maciel, Tavares Alice Thomaz, Carneiro Ana Carolina Aguiar Vasconcelos, Arantes Rosa Maria Esteves, Vitor Ricardo Wagner Almeida
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil.
Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG 31270-901, Brazil.
Exp Parasitol. 2015 Sep;156:87-94. doi: 10.1016/j.exppara.2015.06.002. Epub 2015 Jun 10.
There is a lack of studies using Toxoplasma gondii strains isolated from human patients. Here, we present a pathological study of three strains obtained from human cases of congenital toxoplasmosis in Brazil using inbred mice after oral infection with 10 tissue cysts. Multiplex-nested PCR-RFLP of eleven loci revealed atypical genotypes commonly found in Brazil: toxodb #8 for TgCTBr5 and TgCTBr16 strains and toxodb #11 for the TgCTBr9 strain. BALB/c and C57BL/6 mice were evaluated for survival and histological changes during the acute phase of the disease. All mice inoculated with the non-virulent TgCTBR5 strain survived after 30 days, although irreversible tissue damage was found. In contrast, no mice were resistant to infection with the highly virulent TgCTBR9 strain. The TgCTBr16 strain resulted in 80% survival in mice. However, this strain presented low infectivity, especially by the oral route of infection. Despite being identified with the same genotype, TgCTBr5 and TgCTBr16 strains showed biological differences. Histopathologic analysis revealed liver and lungs to be the most affected organs, and the pattern of tissue injury was similar to that found in mice inoculated perorally with strains belonging to clonal genotypes. However, there was a variation in the intensity of ileum lesions according to T. gondii strain and mouse lineage. C57BL/6 mice showed higher susceptibility than BALB/c for histological lesions. Taken together, these results revealed that the pathogenesis of T. gondii strains belonging to atypical genotypes can induce similar tissue damage to those from clonal genotypes, although intrinsic aspects of the strains seem critical to the induction of ileitis in the infected host.
目前缺乏使用从人类患者分离出的弓形虫菌株进行的研究。在此，我们报告了一项病理学研究，该研究使用10个组织包囊经口感染近交系小鼠，对从巴西先天性弓形虫病人类病例中获得的三株菌株进行了研究。对11个位点进行多重巢式PCR-RFLP分析，结果显示这些菌株具有巴西常见的非典型基因型：TgCTBr5和TgCTBr16菌株为toxodb #8，TgCTBr9菌株为toxodb #11。对BALB/c和C57BL/6小鼠在疾病急性期的生存情况和组织学变化进行了评估。所有接种无毒力TgCTBR5菌株的小鼠在30天后均存活，尽管发现了不可逆的组织损伤。相比之下，没有小鼠对高毒力TgCTBR9菌株的感染具有抵抗力。TgCTBr16菌株使80%的小鼠存活。然而，该菌株的感染性较低，尤其是经口感染途径。尽管TgCTBr5和TgCTBr16菌株具有相同的基因型，但它们表现出生物学差异。组织病理学分析显示，肝脏和肺是受影响最严重的器官，组织损伤模式与经口接种属于克隆基因型的菌株的小鼠相似。然而，根据弓形虫菌株和小鼠品系的不同，回肠病变的严重程度存在差异。C57BL/6小鼠在组织学损伤方面比BALB/c小鼠更易感。综上所述，这些结果表明，属于非典型基因型的弓形虫菌株的发病机制可诱导与克隆基因型菌株相似的组织损伤，尽管菌株的内在特性似乎对感染宿主中回肠炎的诱导至关重要。
