Toxoplasma gondii:: Genotyping patients with cerebral toxoplasmosis of strains from Brazilian AIDS by multilocus PCR-RFLP markers
Toxoplasma gondii:: Genotyping patients with cerebral toxoplasmosis of strains from Brazilian AIDS by multilocus PCR-RFLP markers
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DOI：
10.1016/j.exppara.2007.08.006
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发表时间：
2008-02-01
影响因子：
2.1
通讯作者：
Pereira-Chioccola, Vera L.
中科院分区：
文献类型：
--
作者：
Ferreira, Isabelle M. R.;Vidal, Jose E.;Pereira-Chioccola, Vera L.
本研究调查了从巴西圣保罗州收治的87例脑弓形虫病和艾滋病患者中分离的弓形虫菌株的基因特征。脑弓形虫病的实验室诊断是基于阳性的血清学检查和血液和/或脑脊液的聚合酶链式反应。选择4个标记(5‘-SAG2、3’-SAG2、SAG3和GRA6)对样本进行分析。用限制性内切酶-限制性内切酶(PCR-RFLP)对扩增后的3个克隆谱系进行限制性内切酶酶切分析。基因分型结果为：I型40例(46%)，III型4例(4%)，多态菌株13例(15%)，I型或II型6例，未分类菌株15例(17%)。PCR-RFLP也将9株(11%)临床分离株归类为II型，这在南美洲很少见。然而，对II型和5‘-SAG2、SAW和GRA6标记的多态分离物的套式-聚合酶链式反应产物(SAG3标记)的测序结果显示，与原型克隆基因型(I、II和III型)相比，这些分离物显示了核苷酸多态，这些分离物被认为是多态分离物。这里使用的标记不适合区分大多数被认为是多态菌株的菌株。这些数据证实了其他研究表明，在巴西分离的弓形虫菌株具有很高的遗传多态比率。(C)2007 Elsevier Inc.保留所有权利。
This study investigated the genetic characteristics of the Toxoplasma gondii strains isolated from 87 patients with cerebral toxoplasmosis and AIDS, treated in Sao Paulo State, Brazil. The laboratorial diagnosis of cerebral toxoplasmosis was based on positive serological exams and PCR of blood and/or cerebrospinal fluid. Four markers (5'-SAG2, 3'-SAG2, SAG3 and GRA6) were chosen to analyze the samples. Each having clear resolution to distinguish the three clonal lineages after PCR amplified targets were treated with restriction enzyme digestion (PCR-RFLP). The genotyping provided the following results: 40 patients (46%) were infected with strains classified as type I; 4 (4%), as type III; 13 (15%) were infected with polymorphic strains (unusual genotype); 6 patients with type I or II alleles; and 15 (17%) patients had strains not classified for any marker. PCR-RFLP, also classified 9 (11%) clinical isolates as type II, which is uncommon in South America. However, the sequencing of the nested-PCR products (of SAG3 marker) of type II and polymorphic isolates (of 5'-SAG2, SAW and GRA6 markers) showed a nucleotide polymorphism compared with the archetypal clonal genotypes (types I, II and III) and these isolates were considered as polymorphic strains. The markers used here were inappropriate to distinguish the most isolates considered as polymorphic strains. These data confirm other studies showing the high rate of genetic polymorphism in T gondii strains isolated in Brazil. (C) 2007 Elsevier Inc. All rights reserved.