Chikweto Alfred, Sharma Ravindra N, Tiwari Keshaw P, Verma Shiv K, Calero-Bernal Rafael, Jiang Tiantian, Su Chunlei, Kwok Oliver C, Dubey Jitender P
Pathobiology Department, School of Veterinary Medicine, St. George's University, Grenada, West Indies.
J Parasitol. 2017 Feb;103(1):52-55. doi: 10.1645/15-945. Epub 2016 Oct 24.
The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to other genotypes in Grenada.
本横断面研究的目的是从西印度群岛格林纳达的散养鸡中分离出刚地弓形虫并进行基因分型。使用改良凝集试验，在145只散养鸡中有39只（26.9%）检测到抗刚地弓形虫抗体，其中7只鸡的抗体滴度为25，6只鸡为50，2只鸡为100，24只鸡为200或更高。对39只血清阳性鸡的心脏在小鼠中进行生物测定；从20只鸡中分离出了活的刚地弓形虫，并在细胞培养中进一步繁殖。使用10种PCR-限制性片段长度多态性（RFLP）标记SAG1、SAG2、SAG3、BTUB、GRA6、c22-8、c29-2、L358、PK1和Apico对从细胞培养的速殖子中提取的刚地弓形虫DNA进行基因分型，发现了4种基因型，包括ToxoDB PCR-RFLP编号2（III型）、编号7、编号13和编号259（新基因型）。这些结果表明，与格林纳达的其他基因型相比，散养鸡中刚地弓形虫的群体遗传学似乎具有中等程度的多样性，其中ToxoDB编号2（III型）最为常见（15/20 = 75%）。
