Vieira Fernando Emmanuel Gonçalves, Sasse João Pedro, Minutti Ana Flávia, Miura Ana Carolina, de Barros Luiz Daniel, Cardim Sergio Tosi, Martins Thais Agostinho, de Seixas Mércia, Yamamura Milton Issashi, Su Chunlei, Garcia João Luis
Parasitology and Zoology Laboratory, Universidade Estadual do Norte do Paraná - UENP, Jacarezinho, PR, Brazil.
Protozoology Laboratory, Preventive Veterinary Medicine Departament, Universidade Estadual de Londrina, Londrina, PR, Brazil.
Parasitol Res. 2018 Mar;117(3):681-688. doi: 10.1007/s00436-017-5730-5. Epub 2018 Jan 18.
Toxoplasma gondii is an intracellular parasite that can infect all warm-blooded animals including humans. Recent studies showed that T. gondii strains from South America are genetically diverse. The present work aimed to determine T. gondii prevalence in free-ranging chicken in northwest Parana state in Brazil by two serological tests, to isolate the parasites from seropositive chickens and to genotype the isolates. Antibodies to T. gondii in 386 serum samples from 24 farms were investigated by immunofluorescence antibody assay (IFA) and modified agglutination test (MAT). Samples having titers ≥ 16 were considered positive for both tests. Among the 386 serum samples, 102 (26.4%) were positive for IFA, 64 (16.6%) were positive for MAT, 47 (12.2%) were positive in both tests, and 119 (30.8%) were positive in at least one of the two tests. Brain and pool of heart, lung, and liver from the 119 seropositive chickens were used for mouse bioassay to isolate the parasites. Thirty eight (31.9%) of these seropositive chickens were considered positives in mouse bioassay and 18 isolates were obtained. The isolates were characterized by 10 PCR-RFLP genetic markers including SAG1, SAG2 (5'-3'SAG2, alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Results of genotyping were compared with the genotypes in ToxoDB database. It revealed ten genotypes, including ToxoDB PCR-RFLP genotypes #6 (n = 2), #19 (n = 1), #21 (n = 2), #111 (n = 2), #152 (n = 1), and #175 (n = 1) and four new types not described before. Our results confirmed a high genetic diversity of this parasite in southern Brazil and also showed that the use of two serological tests in combination can improve the chance of T. gondii isolation. More studies should be taken to determine the zoonotic potential of chickens in the transmission of T. gondii.
刚地弓形虫是一种细胞内寄生虫，可感染包括人类在内的所有温血动物。最近的研究表明，来自南美洲的刚地弓形虫菌株在基因上具有多样性。本研究旨在通过两种血清学检测方法确定巴西巴拉那州西北部自由放养鸡肉中刚地弓形虫的流行情况，从血清学阳性鸡中分离寄生虫并对分离株进行基因分型。通过免疫荧光抗体试验（IFA）和改良凝集试验（MAT）对来自24个农场的386份血清样本中的刚地弓形虫抗体进行了检测。两种检测中滴度≥16的样本被视为阳性。在386份血清样本中，102份（26.4%）IFA检测呈阳性，64份（16.6%）MAT检测呈阳性，47份（12.2%）两种检测均呈阳性，119份（30.8%）至少在两种检测中的一种呈阳性。来自119只血清学阳性鸡的脑以及心脏、肺和肝脏的混合样本用于小鼠生物测定以分离寄生虫。这些血清学阳性鸡中有38只（31.9%）在小鼠生物测定中被视为阳性，并获得了18株分离株。通过包括SAG1、SAG2（5'-3'SAG2、alt.SAG2）、SAG3、BTUB、GRA6、c22-8、c29-2、L358、PK1和Apico在内的10个PCR-RFLP基因标记对分离株进行了鉴定。基因分型结果与ToxoDB数据库中的基因型进行了比较。结果显示有10种基因型，包括ToxoDB PCR-RFLP基因型#6（n = 2）、#19（n = 1）、#21（n = 2）、#111（n = 2）、#152（n = 1）和#175（n = 1）以及4种以前未描述过的新类型。我们的结果证实了这种寄生虫在巴西南部具有高度的遗传多样性，还表明联合使用两种血清学检测方法可以提高刚地弓形虫分离的几率。应开展更多研究以确定鸡在刚地弓形虫传播中的人畜共患病潜力。
