Laboratório de Parasitologia, Instituto Adolfo Lutz, SP, Brazil.
Exp Parasitol. 2011 Oct;129(2):190-5. doi: 10.1016/j.exppara.2011.06.002. Epub 2011 Jun 30.
This study investigated the genetic characteristics of Toxoplasma gondii samples collected from 62 patients with toxoplasmosis in Sao Paulo State, Brazil. DNA samples were isolated from blood, cerebrospinal fluid and amniotic fluids of 25 patients with cerebral toxoplasmosis and AIDS, two patients with acute toxoplasmosis, 12 patients with ocular toxoplasmosis, six newborns with congenital toxoplasmosis and 17 pregnant women with acute infection. Diagnosis of toxoplasmosis was based in clinical, radiological and laboratory features. Genotyping was performed using multilocus PCR-RFLP genetic markers including SAG1, SAG2, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, C22-8, c29-2, L358, PK1 and Apico. Among the 62 clinical samples, 20 (32%) were successfully genotyped at eight or more genetic loci and were grouped to three distinct genotypes. Eighteen samples belonged to ToxoDB Genotype #65 and the other two samples were identified as ToxoDB Genotypes #6 and #71, respectively (http://toxodb.org/toxo/). Patients presenting Genotypes #6 and #71 had severe and atypical cerebral toxoplasmosis, characterized by diffuse encephalitis without extensive brain lesions. These results indicate that T. gondii Genotype #65 may have a high frequency in causing human toxoplasmosis in Sao Paulo State, Brazil. This unusual finding highlights the need to investigate the possible association of parasite genotypes with human toxoplasmosis.
本研究调查了巴西圣保罗州 62 例弓形虫病患者的弓形虫样本的遗传特征。从 25 例脑弓形虫病和艾滋病患者、2 例急性弓形虫病患者、12 例眼弓形虫病患者、6 例先天性弓形虫病新生儿和 17 例急性感染孕妇的血液、脑脊液和羊水分离出 DNA 样本。弓形虫病的诊断基于临床、影像学和实验室特征。采用多基因座 PCR-RFLP 遗传标记（包括 SAG1、SAG2、5'-和 3'-SAG2、alt.SAG2、SAG3、BTUB、GRA6、C22-8、c29-2、L358、PK1 和 Apico）进行基因分型。在 62 例临床样本中，有 20 例（32%）在 8 个或更多遗传位点成功进行了基因分型，并分为 3 种不同的基因型。18 个样本属于 ToxoDB 基因型 #65，另外两个样本分别被鉴定为 ToxoDB 基因型 #6 和 #71（http://toxodb.org/toxo/）。携带基因型 #6 和 #71 的患者患有严重和非典型的脑弓形虫病，表现为无广泛脑损伤的弥漫性脑炎。这些结果表明，T. gondii 基因型 #65 可能在巴西圣保罗州引起人类弓形虫病的频率较高。这一不寻常的发现强调了需要研究寄生虫基因型与人类弓形虫病之间可能存在的关联。
