[Effect of Toxoplasma gondii prugniaud strain infection in pregnant mice on the learning ability of the F1 generation].

Objective: To study the effect of Toxoplasma gondii prugniaud strain infection on female reproductive toxicity in mice and learning ability of their F1 generation.

Methods: Thirteen ICR mice were each infected intragastrically with 10 T. gondii cysts on the 15th day of pregnancy (late stage pregnancy). 12 mice were treated with physiological saline as control. The time from conception to birth and the number of offspring were recorded. Three mice from each group were sacrificed when pregnant 20 d, placentas from the sacrificed and output stillbirth mice were examined by using histopathology and immunohistochemistry. DNA extraction was performed from placenta tissue, and then T. gondii B1 gene was amplified by PCR. The F1 generation mice from experiment group and control group were tested by Morris water maze test. Statistical analysis on learning and memory ability was made by SPSS 13.0 software.

Results: The time from conception to birth in experiment group [(19.2 +/- 1.751)d] was shorter than that in control group [(21.0 +/- 1.732)d] (P < 0.05). No significant difference was found in the number of offspring between experiment group (70) and control group (85) (P > 0.05). Microscopic examination with HE staining showed multiple T. gondii among placental villi, the increase of the number of Hofbauer cells, blood sinus expansion and hyperemia, and visible nucleated erythrocytes. Immunohistochemically, T. gondii antigen was detected in placenta tissue. T. gondii B1 gene was detected in placenta tissue (194 bp). On the third and fourth day of the Morris water maze test, the latency of experiment group [(29.92 +/- 4.28) s, (27.69 +/- 6.23) s] was longer than that of the control [(24.07 +/- 5.32) s, (22.25 +/- 7.94) s] (P < 0.05). In the spatial probe test, the distance across the platform quadrant of experiment group [(384.66 +/- 41.33) cm] was shorter than that of the control [(426.12 +/- 46.48) cm] (P < 0.05).

Conclusion: T. gondii Prugniaud strain infection in late stage pregnancy of mice may induce reproductive toxicity and affect the learning and memory capability of the F1 generation.