BACKGROUND Cats as a definitive host have an important role in the epidemiology of toxoplasmosis in humans and animals. The aim of the study was to determine the frequency of Toxoplasma gondii infection and isolate and identify the genotypes of T. gondii in stray cats in the Mashhad suburb. METHODS From April 2016 to August 2017, 175 fecal samples from stray cats and 31 brain samples from cats killed in driving accidents were collected. The fecal samples were examined by fecal flotation technique and T. gondii-specific PCR. The brain samples were investigated by T. gondii-specific PCR and consequently examined by mice bioassay. The DNA of T. gondii isolated was genotyped using SAG1, SAG2, SAG3, BTUB and GRA6 as PCR-restriction fragment length polymorphism (PCR-RFLP) markers. RESULTS In the present study, Toxoplasma-like oocysts were microscopically observed in 2.2% (4/175) fecal samples. The presence of Toxoplasma oocysts was confirmed in one microscopy-positive sample by PCR. In addition, T. gondii DNA was detected in 4% (7/175) microscopy-negative samples using PCR. T. gondii was isolated from one brain PCR-positive sample by mice bioassay. The isolate was avirulent and many T. gondii cysts were observed in mice brain. The isolate was successfully genotyped by PCR-RLFP analysis. The isolated genotyped was type II. Besides, eight Toxoplasma-positive fecal samples contained insufficient DNA and only amplified at SAG-3 locus in PCR. These samples were also showed type II pattern at this locus. CONCLUSIONS Parasitological and molecular results showed low frequency of Toxoplasma infection in the stray cats, and identified the genotype of T. gondii isolate as type II, for the first time in Mashhad area, Khorasan Razavi Province.

中文翻译：

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伊朗马什哈德地区流浪猫弓形虫的患病率和基因分型。

背景技术猫作为最终宿主在人类和动物弓形体病的流行病学中具有重要作用。该研究的目的是确定马什哈德郊区流浪猫中弓形虫感染的频率，并分离和鉴定弓形虫的基因型。方法 2016年4月至2017年8月，采集流浪猫粪便样本175份，交通事故死亡猫大脑样本31份。通过粪便浮选技术和弓形虫特异性 PCR 对粪便样本进行检查。大脑样本通过弓形虫特异性 PCR 进行研究，随后通过小鼠生物测定进行检查。使用 SAG1、SAG2、SAG3、BTUB 和 GRA6 作为 PCR 限制性片段长度多态性 (PCR-RFLP) 标记，对分离的弓形虫 DNA 进行基因分型。结果在本研究中，在2.2%（4/175）的粪便样本中通过显微镜观察到弓形虫样卵囊。通过 PCR 证实了一份显微镜检查呈阳性的样本中存在弓形虫卵囊。此外，使用 PCR 在 4% (7/175) 显微镜检查阴性样本中检测到弓形虫 DNA。通过小鼠生物测定从一份脑 PCR 阳性样本中分离出弓形虫。该分离株无毒力，并且在小鼠脑中观察到许多弓形虫包囊。通过 PCR-RLFP 分析成功地对该分离株进行了基因分型。分离的基因型为II型。此外，8个弓形虫阳性粪便样本DNA含量不足，且仅在PCR中的SAG-3位点进行扩增。这些样本在该位点也显示出 II 型模式。结论 寄生虫学和分子生物学结果显示，呼罗珊省马什哈德地区流浪猫弓形虫感染频率较低，弓形虫基因型为II型。