de Souza Fernandes Norberto, Caliari Marcelo Vidigal, Oliveira Fabricio Marcos Silva, Neto Alexandre Batista Costa, Rodrigues Isabela Aurora, Furst Cinthia, Costa Adriana Oliveira
Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Belo Horizonte, Brazil.
Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.
Parasitol Res. 2023 May;122(5):1167-1175. doi: 10.1007/s00436-023-07817-3. Epub 2023 Mar 16.
Species of the genus Acanthamoeba are free-living protozoans that occasionally act as parasites, causing a severe, progressive corneal infection termed Acanthamoeba keratitis (AK). The variable pathogenic potential among Acanthamoeba lineages has been shown by in vitro assays, but little is known about the behavior of different strains in animal models of AK. This work aimed to evaluate the infectivity of Acanthamoeba from distinct morphological groups and genotypes in a rat model of AK and apply an immunohistochemical technique for histological characterization of the lesions. Only a strain classified as group I/genotype T17, isolated from a soil source, caused ulcerated corneal lesions in two Wistar rats (n = 9) subjected to intrastromal inoculation. Two strains derived from AK human cases (group II/genotype T4 and group III/genotype T5) did not induce corneal lesions in the rats. A previous association of group II/genotype T4 trophozoites with lethally irradiated Escherichia coli did not influence the infectivity. A hyperimmune serum produced in Wistar rats was validated by an immunocytochemical technique using the three distinct strains and then applied for immunohistochemistry. The abundance of antigenic residues was observed in both corneas with keratitis, suggesting that the infectious process tended to resolve. Despite the low infection rate of the AK Wistar rat model, we produced an immunochemical tool with a potential diagnostic application. We also showed for the first time the ability of Acanthamoeba from T17 genotype to cause AK in experimental conditions.
棘阿米巴属的物种是自由生活的原生动物，偶尔会作为寄生虫，引发一种严重的、进行性的角膜感染，称为棘阿米巴角膜炎（AK）。体外试验已表明棘阿米巴谱系之间存在不同的致病潜力，但对于不同菌株在AK动物模型中的行为了解甚少。这项工作旨在评估来自不同形态学组和基因型的棘阿米巴在AK大鼠模型中的感染性，并应用免疫组织化学技术对病变进行组织学特征分析。仅一种从土壤来源分离的、分类为I组/T17基因型的菌株，在9只接受基质内接种的Wistar大鼠中的2只身上引起了溃疡性角膜病变。来自AK人类病例的两种菌株（II组/T4基因型和III组/T5基因型）未在大鼠中诱发角膜病变。II组/T4基因型滋养体与经致死性照射的大肠杆菌的先前关联并未影响其感染性。通过使用三种不同菌株的免疫细胞化学技术验证了在Wistar大鼠中产生的超免疫血清，然后将其应用于免疫组织化学。在两只患有角膜炎的角膜中均观察到丰富的抗原性残留物，这表明感染过程趋于消退。尽管AK Wistar大鼠模型的感染率较低，但我们制备了一种具有潜在诊断应用价值的免疫化学工具。我们还首次展示了T17基因型的棘阿米巴在实验条件下引发AK的能力。
