Discipline of Parasitology, Department of Biological Sciences, Universidade Federal do Triângulo Mineiro, Rua Frei Paulino, 30, Bairro Abadia, 38025-180, Uberaba, Minas Gerais, Brazil.
Parasitol Res. 2013 Feb;112(2):671-8. doi: 10.1007/s00436-012-3184-3. Epub 2012 Nov 18.
The congenital transmission of Chagas disease is associated with an increase in parasitemia during pregnancy, maternal and fetal immunity, and populations of Trypanosoma cruzi. In this study, the biological behavior of TcI and TcV (isolated from a human congenital case) strains and their potential for experimental congenital transmission were evaluated in female BALB/C mice. Parasitemia was estimated by fresh blood examination, semiquantitative microhematocrit, and hemoculture, while congenital transmission was evaluated by culture in the liver infusion tryptose medium and by polymerase chain reaction (PCR) of the pups' tissues on postnatal day 7 and of the pups' blood sample at 30 days after birth. Infection was detected in 100 % of the females. Both strains showed subpatent parasitemia, which was higher for TcV infection. The presence of amastigote nest was detected only in an animal infected with TcI. The inflammatory process was more frequent (p = 0.001) in the tissues of the animals infected with TcV (58.6 %) than TcI (31.1 %). The fertility rates of females mated after 35 days postinfection were similar (90 % for TcV, 88.9 % for TcI; p = 0.938). Parasitemia did not change during pregnancy. The average number of pups/female was greater (p = 0.03) in mice with TcV infection (8.30) than in those with TcI infection (4.78). Congenital transmission was detected exclusively by PCR in 50.9 % of the pups, 46.6 % for TcV and 58.1 % for TcI. The PCR positivity for TcI was higher in the blood than in the tissue (p = 0.003). These results demonstrate the T. cruzi experimental congenital infection associated with subpatent maternal parasitemia of TcI and TcV.
克氏锥虫病的先天性传播与怀孕期间寄生虫血症的增加、母婴免疫和克氏锥虫的种群有关。在这项研究中，评估了来自人类先天性病例的 TcI 和 TcV（分离株）菌株的生物学行为及其实验性先天性传播的潜力，在雌性 BALB/C 小鼠中进行。通过新鲜血液检查、半定量微血球压积和血培养来估计寄生虫血症，通过肝浸液琼脂培养基培养和聚合酶链反应（PCR）评估先天性传播在产后第 7 天和出生后 30 天对幼鼠组织的检测和幼鼠血液样本。100%的雌性感染。两种株系均表现出亚隐性寄生虫血症，TcV 感染的寄生虫血症更高。只有感染 TcI 的动物中才检测到阿米巴巢穴。感染 TcV（58.6%）的动物组织中炎症反应更为频繁（p = 0.001），而 TcI（31.1%）则较少。感染后 35 天交配的雌性的生育力相似（TcV 为 90%，TcI 为 88.9%；p = 0.938）。怀孕期间寄生虫血症没有变化。感染 TcV 的雌性幼鼠数量（8.30）多于感染 TcI 的雌性幼鼠（4.78）（p = 0.03）。通过 PCR 仅在 50.9%的幼鼠中检测到先天性传播，TcV 为 46.6%，TcI 为 58.1%。PCR 阳性率 TcI 在血液中高于组织（p = 0.003）。这些结果表明，与 TcI 和 TcV 的母体亚隐性寄生虫血症相关的克氏锥虫实验性先天性感染。
