Determination of genotypes of Toxoplasma gondii strains isolated from patients with toxoplasmosis
Determination of genotypes of Toxoplasma gondii strains isolated from patients with toxoplasmosis
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DOI：
10.1128/jcm.35.6.1411-1414.1997
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发表时间：
1997-06-01
影响因子：
9.4
通讯作者：
Sibley, LD
中科院分区：
文献类型：
--
作者：
Howe, DK;Honore, S;Sibley, LD
为了确定弓形虫与人类弓形虫病相关的菌株的基因分型，我们建立了一种从临床标本中短期体外培养的寄生虫进行分型的灵敏方法，一种新的套式PCR方法能够在宿主组织存在的情况下从五种寄生虫中扩增出基因组DNA。根据编码速殖子表面抗原p22的SAG2基因座的DNA多态进行分型。利用聚合酶链式反应扩增的SAG2产物中的限制性片段长度多态性，将菌株分为弓形虫的三个主要谱系之一。用该方法成功地对先天、脑和播散性弓形虫病患者分离的72份标本中的68份进行了基因分型，大多数样本中检出了弓形虫II型菌株，占68例弓形虫病病例的81%，而在68例弓形虫病患者中，只有7例(10%)和6例(9%)检出了I型和III型菌株。本研究的结果支持了以前的发现，即II型菌株最常与人类弓形虫病有关。SAG2基因座的套式聚合酶链式反应分析提供了弓形虫的特定基因的快速分配，这在分析各种临床样本时应该是有用的。
To determine the genotypes of Toxoplasma gondii strains associated with human toxoplasmosis, we developed a sensitive approach for typing parasites grown from clinical samples by short-term in vitro culture, A newly described nested PCR assay was capable of amplifying genomic DNA from as few as five parasites in the presence of host tissues. Typing was based on DNA polymorphisms at the SAG2 locus, encoding tachyzoite surface antigen p22. Restriction fragment length polymorphisms in PCR-amplified SAG2 products were used to classify strains into one of the three major lineages of T. gondii. This approach was successfully used to determine the genotypes of 68 of 72 samples that had been previously isolated from patients with congenital, cerebral, and disseminated toxoplasmosis, Type II strains of T. gondii were found in a majority of the samples, accounting for 55 (81%) of the 68 toxoplasmosis cases, In contrast, type I and III strains were found in only 7 (10%) and 6 (9%) of the 68 cases, respectively, The results of this study support the previous finding that type II strains are most often associated with human toxoplasmosis, Nested PCR analysis at the SAG2 locus provides rapid assignment of T. gondii to a specific genotype that should be useful in analyzing a variety of clinical samples.