Valenzuela-Moreno Luis Fernando, Rico-Torres Claudia Patricia, Cedillo-Peláez Carlos, Luna-Pastén Héctor, Méndez-Cruz Sara Teresa, Lara-Martínez Gabriela, Correa Dolores, Caballero-Ortega Heriberto
Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Colonia Insurgentes-Cuicuilco, Delegación Coyoacán, C.P. 04530, Ciudad de México, Mexico; Programa de Doctorado en Ciencias de la Producción y de la Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico.
Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Colonia Insurgentes-Cuicuilco, Delegación Coyoacán, C.P. 04530, Ciudad de México, Mexico.
Acta Trop. 2019 May;193:199-205. doi: 10.1016/j.actatropica.2019.03.006. Epub 2019 Mar 6.
Toxoplasmosis is a zoonosis caused by Toxoplasma gondii that infects homeothermic animals, including humans. To date, as many as 287 genotypes have been described worldwide. Genetic characterization of the parasite is crucial because the parasite type can determine the presentation and severity of toxoplasmosis. Previously, we reported that the Yucatán Peninsula has a frequency of infection of over 70% in humans and other animals; moreover, there are seven species of felids, including domestic cats; thus, we hypothesized that this might be a region with a high diversity of the parasite. Nevertheless, no genotyping of this protozoan has been performed in this region. Thus, the aim of this study was to genotype T. gondii from naturally infected feral cats of Quintana Roo, within the Yucatán Peninsula, and to describe its genetic variability. Eleven feral cats were captured and bled to obtain the buffy coat; then, they were euthanized to collect target organs or tissues to extract DNA. Samples were processed by PCR for diagnosis, and ten polymorphic markers were genotyped by PCR-RFLP. Atypical GRA6 gene products were cloned and sequenced. Ten of the eleven cats were PCR positive for toxoplasmosis in blood; of these, seven had mixed infections. Also, two isolates were obtained from the heart and diaphragm of two animals. At least 23 different genotypes were detected, from which 18 are new worldwide. From the atypical GRA6 gene cloning and sequencing analysis, a mixed infection was discovered, due to one strain identical to GT1 and another to VAND. In conclusion, T. gondii genetic diversity in the region is high and different from that in other regions, with new genotypes exclusive to México and some others shared with USA and South America.
弓形虫病是一种由刚地弓形虫引起的人畜共患病，可感染包括人类在内的恒温动物。迄今为止，全球已描述了多达287种基因型。对该寄生虫进行基因特征分析至关重要，因为寄生虫类型可决定弓形虫病的表现和严重程度。此前，我们报道尤卡坦半岛人类和其他动物的感染率超过70%；此外，该地区有七种猫科动物，包括家猫；因此，我们推测这可能是一个寄生虫多样性高的地区。然而，该地区尚未对这种原生动物进行基因分型。因此，本研究的目的是对尤卡坦半岛金塔纳罗奥州自然感染的野猫体内的刚地弓形虫进行基因分型，并描述其遗传变异性。捕获了11只野猫并采集血液以获取血沉棕黄层；然后对它们实施安乐死以收集目标器官或组织来提取DNA。通过PCR对样本进行处理以进行诊断，并通过PCR-RFLP对十个多态性标记进行基因分型。对非典型GRA6基因产物进行克隆和测序。11只猫中有10只血液中弓形虫病PCR检测呈阳性；其中7只存在混合感染。此外，从两只动物的心脏和横膈膜中获得了两个分离株。至少检测到23种不同的基因型，其中18种在全球范围内是新发现的。通过非典型GRA6基因克隆和测序分析，发现了一种混合感染，其中一个菌株与GT1相同，另一个与VAND相同。总之，该地区刚地弓形虫的遗传多样性很高，与其他地区不同，有墨西哥特有的新基因型，还有一些与美国和南美洲共有的基因型。
