伊朗西南部鸟类分离株弓形虫的检测和基因分型。

The aim of this work was to determine the frequency of occurrence of Toxoplasma gondii and genetically analyse isolates from a number of avian hosts in the southwest of Iran (Khuzestan province). The frequency of T. gondii was determined in free-range chickens (Gallus domesticus), sparrows (Passer domesticus), pigeons (Columba livia) and starlings (Sturnus vulgaris). 2. Isolates obtained from Toxoplasma-infected birds were subjected to molecular typing by PCR-restriction fragment length polymorphism (RFLP) with sequence analysis of the GRA6 gene. 3. The results showed that 41 (16·5%) of 241 samples of avian tissue were infected with T. gondii. Sparrows were most frequently infected (17 out of 64). 4. Analysis of the GRA6 gene by PCR-RFLP and DNA sequencing revealed Type II and III T. gondii were the predominant lineage, accounting for 19·5% and 80·5% of the isolates, respectively. 5. It was concluded that the use of this PCR test facilitated the diagnosis of T. gondii in avian hosts and the GRA6 PCR-RFLP method clearly differentiated between the three different T. gondii lineages. This study showed a higher prevalence of type III compared with type II T. gondii in infected avian hosts in southwestern Iran.

本研究旨在确定伊朗西南部（胡齐斯坦省）多种禽类宿主中弓形虫的发生频率，并对分离株进行基因分析。对自由放养的鸡（Gallus domesticus）、麻雀（Passer domesticus）、鸽子（Columba livia）和八哥（Sturnus vulgaris）进行了弓形虫感染频率的检测。
从感染弓形虫的鸟类中分离出的分离株，通过 PCR-限制性片段长度多态性（RFLP）进行分子分型，并对 GRA6 基因进行序列分析。
结果显示，在 241 份禽组织样本中，有 41 份（16.5%）感染了弓形虫。麻雀的感染率最高（64 只中有 17 只）。
通过 PCR-RFLP 和 DNA 测序对 GRA6 基因进行分析显示，II 型和 III 型弓形虫是主要的谱系，分别占分离株的 19.5%和 80.5%。
综上所述，该 PCR 检测方法有助于诊断禽类宿主中的弓形虫，GRA6 PCR-RFLP 方法可明确区分三种不同的弓形虫谱系。本研究表明，与 II 型弓形虫相比，III 型在伊朗西南部感染禽类宿主中的流行率更高。

Detection and genotyping of Toxoplasma gondii strains isolated from birds in the southwest of Iran.