Vilares Anabela, Gargaté Maria João, Ferreira Idalina, Martins Susana, Gomes João Paulo
National Reference Laboratory of Parasitic and Fungal Infections, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal.
Research and Development Unit, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal.
Parasitol Res. 2017 Mar;116(3):979-985. doi: 10.1007/s00436-017-5374-5. Epub 2017 Jan 30.
Toxoplasma gondii is an apicomplexan parasite responsible for toxoplasmosis which infects all warm-blooded vertebrates, including mammals and birds. The majority of studies conducted in Europe have revealed that more than 80 % of strains isolated from human infections belong to genotype II, whereas genotypes I and III are responsible for a small number of cases. Atypical and recombinant strains are generally associated with more severe infections. In Portugal, there is a lack of data concerning genetic diversity as the classical typing studies in humans have never been performed. We aimed to determine the Sag2 and microsatellite-based (TUB2, TgM-A, W35, B17, B18) genotypes of T. gondii isolated from humans in Portugal, as well as to study their virulence in mice. We analyzed 48 strains from congenital and acquired toxoplasmosis collected during the last two decades. Sag2-based genotyping of T. gondii was achieved in all 48 strains where 35 (73 %) were classified as type II and 13 (27 %) were type I. The multilocus PCR of five microsatellites allowed the classification of 10 strains (21 %) as recombinant strains that had been previously identified as type II or I by Sag2 typing. Seven out of the 48 strains, including three type I, three recombinant, and one type I, were virulent in mice. This study constitutes the first evidence of recombinant strains circulating in Portugal in humans from congenital infection, highlighting the need for a better evaluation of these strains as their phenotype is still barely understood.
刚地弓形虫是一种顶复门寄生虫，可引发弓形虫病，能感染包括哺乳动物和鸟类在内的所有温血脊椎动物。欧洲开展的大多数研究表明，从人类感染中分离出的菌株，超过80%属于II型基因型，而I型和III型基因型导致的病例较少。非典型和重组菌株通常与更严重的感染有关。在葡萄牙，由于从未对人类进行过经典分型研究，因此缺乏有关遗传多样性的数据。我们旨在确定从葡萄牙人类中分离出的刚地弓形虫的Sag2和基于微卫星的（TUB2、TgM-A、W35、B17、B18）基因型，并研究它们在小鼠中的毒力。我们分析了过去二十年中收集的48株先天性和获得性弓形虫病的菌株。在所有48株菌株中均实现了基于Sag2的刚地弓形虫基因分型，其中35株（73%）被分类为II型，13株（27%）为I型。五个微卫星的多位点PCR将10株菌株（21%）分类为重组菌株，这些菌株先前通过Sag2分型被鉴定为II型或I型。48株菌株中有7株在小鼠中具有毒力，其中包括3株I型、3株重组型和1株I型。这项研究首次证明了重组菌株在葡萄牙先天性感染的人类中传播，凸显了更好地评估这些菌株的必要性，因为我们对它们的表型仍知之甚少。
