In the intermediate hosts, tachyzoites of T. gondii predominate in the acute stage while bradyzoites persist inside tissue cysts with the potential for reactivation. The two stages exhibit different metabolic and antigenic characters. The present study aimed to investigate temporal expression of Toxoplasma SAG1 and BAG1 genes in the brain tissue and the coincident parasitological and histopathological findings in mice models of toxoplasmosis. The study included group A: mice infected with RH strain and sacrificed 7 days post-infection (p.i.); group B: mice infected with RH strain and treated with sulfamethoxazole-trimethoprim (30 mg/kg/day and 150 mg/kg/day respectively) 24 h p.i. until sacrificed at days 5, 10, or 20 post-treatment; group C: mice infected with ME-49 strain and sacrificed at days 7, 27, 47, or 67 p.i; and group D: mice infected with ME-49 strain and received dexamethasone daily starting at day 68 p.i. and scarified at days 6 or 10 post-treatment. All mice were inspected daily for abnormal physical signs. Peritoneal exudate and brain homogenate were examined for detection of Toxoplasma stages. Brain sections were examined histopathologically. SAG1 and BAG1 gene expression was evaluated using reverse transcription real-time polymerase chain reaction and the ΔΔCt method. Results revealed that marked BAG1 upregulation is consistent with detection of Toxoplasma cysts and degenerative changes while predominance of tachyzoites and inflammatory infiltrate is compatible with SAG1 upregulation. The study sheds light on the potential for using stage-specific gene expression pattern as markers for evaluation of toxoplasmosis disease progression in clinical settings.

在中间宿主中，T速殖子。弓形虫急性期为主，而裂殖子坚持以重新激活的潜在内组织囊肿。这两个阶段表现出不同的代谢和抗原特性。本研究旨在调查弓形虫SAG1和BAG1的时间表达弓形虫病小鼠模型中脑组织中的一些基因以及寄生虫学和组织病理学的同时发现。该研究包括A组：感染RH毒株并在感染后7天处死的小鼠（pi）；B组：感染RH株并用磺胺甲恶唑-甲氧苄氨嘧啶（分别为30mg / kg /天和150mg / kg /天）治疗的小鼠在感染后24小时直至在治疗后第5、10或20天处死。C组：感染ME-49株并在感染后第7、27、47或67天处死的小鼠。D组：感染ME-49株并在pi第68天开始每天接受地塞米松治疗的小鼠，在治疗后第6或10天开始消瘦。每天检查所有小鼠的异常体征。检查腹膜渗出液和脑匀浆以检测弓形虫阶段。对脑切片进行了组织病理学检查。使用逆转录实时聚合酶链反应和ΔΔCt方法评估SAG1和BAG1基因的表达。结果显示，明显的BAG1上调与弓形虫囊肿和退行性变化的检测一致，而速殖子和炎性浸润的优势与SAG1上调兼容。这项研究揭示了使用阶段特异性基因表达模式作为评估弓形虫病在临床环境中疾病进展的标志物的潜力。