Luo W, Aosai F, Ueda M, Yamashita K, Shimizu K, Sekiya S, Yano A
Department of Parasitology, Chiba University School of Medicine, Japan.
J Parasitol. 1997 Dec;83(6):1070-4.
The kinetics of changes in Toxoplasma gondii abundance were evaluated with a quantitative competitive (QC)-polymerase chain reaction (PCR) assay at various sites in both C57BL/6 and BALB/c mice. Higher mortality was apparent in C57BL/6 mice than in BALB/c mice when infected with a high dose of cysts. There were significant differences in cyst number when infected with a low dose of cysts, although there was no significant difference in mortality between the 2 mouse strains. One day after infection with a low dose of an avirulent Fukaya strain, T. gondii was detected in peripheral blood, mesenteric lymph nodes, spleen, lungs, and brain. Two weeks after infection, the number of T. gondii in the brain greatly increased in C57BL/6 mice but not in BALB/c mice. Thus, it would appear that the first to second week after infection is a critical period in determining T. gondii abundance. QC PCR allows the detection of low numbers of T. gondii at an early stage of infection in the murine model. This is useful for the early diagnosis of toxoplasmosis and to understand reactivation of toxoplasmosis.
采用定量竞争（QC）聚合酶链反应（PCR）检测法，评估了C57BL/6和BALB/c小鼠不同部位弓形虫丰度的变化动力学。高剂量包囊感染时，C57BL/6小鼠的死亡率明显高于BALB/c小鼠。低剂量包囊感染时，包囊数量存在显著差异，尽管两种小鼠品系的死亡率无显著差异。低剂量无毒福谷株感染一天后，在周边血液、肠系膜淋巴结、脾脏、肺和脑中检测到弓形虫。感染两周后，C57BL/6小鼠脑中的弓形虫数量大幅增加，而BALB/c小鼠则未增加。因此，感染后的第一至第二周似乎是决定弓形虫丰度的关键时期。QC PCR可在小鼠模型感染早期检测到少量弓形虫。这对于弓形虫病的早期诊断以及了解弓形虫病的再激活很有用。
