Department of Parasitology, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Street, Tianhe District, Guangzhou, Guangdong Province 510642, PR China.
Vet Parasitol. 2010 Oct 29;173(3-4):179-83. doi: 10.1016/j.vetpar.2010.07.011. Epub 2010 Aug 6.
Little is known of the molecular detection of Toxoplasma gondii infection in chickens (Gallus domesticus). The objectives of the present study were to determine the suitable tissues of chickens infected with T. gondii for direct polymerase chain reaction (PCR) amplification of T. gondii DNA. Thirty, 35-day-old broiler chickens were divided into three groups of 10 birds (two replications of five chicks). Of these, two groups were experimentally inoculated intravenously with 4.3×10(6) or 4.3×10(7) tachyzoites of the low virulent T. gondii QHO strain. Two inoculated chickens from each of the two groups were killed on days 7, 14, 21, 28, and 35 post-inoculation, respectively, and two uninoculated chickens were also killed at the same time. Sera from chickens were collected for examination of anti-T. gondii antibodies by indirect hemagglutination test (IHAT) and the modified agglutination test (MAT). Brains, hearts, livers, lungs, spleens and eyes of chickens were sampled and DNA from each tissue was extracted as template for PCR assay. Specific anti-T. gondii antibodies were detected in all infected chickens from day 7 to day 35 p.i. with antibody titers between 1:5 and 1:640 by MAT. PCR assay can detect T. gondii DNA in tissues from the day 21 p.i. to day 28 p.i. This study demonstrates that MAT is more sensitive than IHAT for detecting antibodies to T. gondii in chickens, and PCR assay is a specific, speedy, sensitive and cost-effective method for detecting T. gondii DNA in chickens.
鸡（Gallus domesticus）弓形虫感染的分子检测知之甚少。本研究的目的是确定感染弓形虫的鸡的合适组织，以便直接聚合酶链反应（PCR）扩增弓形虫 DNA。将 30 只 35 日龄的肉鸡分为三组，每组 10 只（两个重复每组 5 只小鸡）。其中两组鸡分别经静脉接种低毒力弓形虫 QHO 株 4.3×10(6)或 4.3×10(7)个速殖子。每组接种的 2 只鸡分别在接种后第 7、14、21、28 和 35 天处死，同时处死 2 只未接种的鸡。收集鸡血清，通过间接血凝试验（IHAT）和改良凝集试验（MAT）检测抗弓形虫抗体。采集鸡的脑、心、肝、肺、脾和眼组织，提取每个组织的 DNA 作为 PCR 检测的模板。MAT 检测到所有感染鸡从第 7 天到第 35 天的特异性抗弓形虫抗体，抗体滴度为 1:5 至 1:640。PCR 检测可在感染后第 21 天至第 28 天检测到组织中的弓形虫 DNA。本研究表明，MAT 比 IHAT 更敏感，可检测鸡体内抗弓形虫的抗体，PCR 检测是一种特异性、快速、敏感且具有成本效益的方法，可检测鸡体内的弓形虫 DNA。
