中文摘要：

目的 通过分析云南大理HIV阳性者感染弓形虫表面抗原SAG1和SAG3基因位点，鉴定该地区HIV阳性者感染弓形虫的基因型。 方法 自云南省艾滋病防治机构收集大理HIV阳性者全血样品291份，运用巢式PCR技术对血样DNA进行弓形虫SAG1和SAG3基因的扩增，扩增产物分别用限制性内切酶Sau96Ⅰ、HaeⅡ和NciⅠ酶切，并对扩增阳性的产物序列进行测定与分析。 结果 291份HIV阳性者血样中，成功扩增出弓形虫SAG1基因64份，SAG3基因42份，产物分别为390 bp和225 bp。扩增产物经酶切后电泳，结果显示，64份SAG1基因均得到2个片段，分别为350 bp和50 bp，42份SAG3基因均得到约200 bp大小的条带，与弓形虫基因Ⅰ型标准株（RH株）结果一致。从酶切的标本中选择多份进行测序，结果与基因Ⅰ型标准株SAG1基因序列（登录号为GQ253073）和SAG3基因序列（登录号为JX218225.1）进行比对分析，发现序列一致性分别为99.98%-100%和99.96%-99.98%。 结论 云南大理HIV阳性者感染弓形虫为基因Ⅰ型。

英文摘要：

Objective To identify the genotypes of Toxoplasma gondii that infects HIV-positive people in Dali of Yunnan Province through analyzing the genetic loci of the surface antigens SAG1 and SAG3. Methods A total of 291 blood samples from HIV-positive cases were collected from the HIV/AIDS Prevention and Control Institution in Yunnan. Nested PCR was used to amplify SAG1 and SAG3 genes in the blood samples. The products were digested with restriction enzymes Sau96Ⅰ, HaeⅡ and NciⅠ, and sequenced. Results Of the 291 HIV-positive blood samples, 64 showed successful amplification of SAG1 gene, and 42 of SAG3 gene, with product sizes of 390 bp and 225 bp, respectively. Enzymetic digestion of the PCR products resulted in fragments of 350 bp and 50 bp for SAG1, and -200 bp band for SAG3, consistent with RH, a particular type Ⅰ strain of T. gondii. Sequencing of the SAG1 and SAG3 PCR products showed that their sequence identities with SAG1 （Accession No. GQ253073） and SAG3（Accession No. JX218225.1） of the type Ⅰ strain of T. gondii were 99.98%-100% and 99.96%-99.98% respectively. Conclusion The Toxoplasma gondii in HIV-positive cases in Dali of Yunnan Province is the type I strain of T. gondii.