Pinckney R D, Lindsay D S, Blagburn B L
Department of Pathobiology, College of Veterinary Medicine, Auburn University, Alabama 36849-5519.
J Parasitol. 1995 Feb;81(1):118-21.
Maternal transmission of Toxoplasma gondii infection to fetuses is important in human and veterinary medicine. Animals, including mice, have been successfully vaccinated with living tachyzoites of the avirulent, nonpersistent, TS-4 temperature-sensitive mutant of T. gondii and have survived challenge infections. We examined in the murine model the persistence of TS-4 infection, transplacental and transmammary transmission, and virulence in neonates. Bioassays of mouse tissues and histological examination of tissues indicated that no viable organisms were present beyond 14 days after inoculation in adult female mice. The TS-4 mutant was not transmitted transplacentally in mice inoculated at 5, 10, or 15 days of gestation and not transmammarily transmitted in mice inoculated 2 days postpartum. Four groups of mouse pups were inoculated subcutaneously with 2 x 10(4), 2 x 10(5) tachyzoites, or with Hanks' balanced salt solution at 2, 3, or 10 days of age. Severe clinical disease and death were observed in 2- or 3-day-old mice and moderate to severe disease was observed in the 10-day-old mice. Results indicate that the TS-4 mutant can cause disease in young nursing mice but is avirulent for pregnant or nonpregnant adult mice.
弓形虫感染从母体传播给胎儿在人类医学和兽医学中都很重要。包括小鼠在内的动物已成功接种无毒、非持续性、TS - 4温度敏感型弓形虫突变株的活速殖子，并在感染攻击后存活下来。我们在小鼠模型中研究了TS - 4感染的持续性、经胎盘和经乳腺传播以及对新生儿的毒力。对小鼠组织的生物测定和组织学检查表明，成年雌性小鼠接种后14天以上不存在活的生物体。TS - 4突变株在妊娠5、10或15天接种的小鼠中不会经胎盘传播，在产后2天接种的小鼠中也不会经乳腺传播。四组幼鼠在2、3或10日龄时皮下接种2×10⁴、2×10⁵速殖子或汉克斯平衡盐溶液。在2日龄或3日龄小鼠中观察到严重的临床疾病和死亡，在10日龄小鼠中观察到中度至重度疾病。结果表明，TS - 4突变株可在哺乳期幼鼠中引起疾病，但对怀孕或未怀孕的成年小鼠无毒力。
