中文摘要：

目的建立田鼠巴贝虫（Babesin microti）的实验动物模型。方法自感染田鼠巴贝虫的种鼠取血，腹腔注射接种3～4周龄雌性BALB／c小鼠（7只）、免疫抑制BALB／c小鼠（4只）、雄性SCID小鼠（4只）和NOD—SCID小鼠（4只）。感染后每天采血，涂制薄血片，吉氏染色，油镜下观察田鼠巴贝虫的生长、增殖情况，记录红细胞的感染率。解剖3只不同红细胞感染率的BALB／c小鼠，油镜下观察心、肝、脾、肺、肾、脑和骨髓等组织的感染情况。记录各组织中红细胞的感染率．并分析与外周血红细胞感染率的关系。取红细胞感染率大于40％的BALB／c小鼠血液．冷冻保存2个月后用同样的方法接种小鼠，观察田鼠巴贝虫的增殖情况。结果BALB／c小鼠、免疫抑制BALB／c小鼠、SCID小鼠和NOD—SCID小鼠接种后，末梢血液中均检测出田鼠巴贝虫。BALB／c小鼠的红细胞感染率在d7达到峰值（82．4％）．免疫抑制BALB／c小鼠的红细胞感染率在d5达到峰值（73．2％），SCID小鼠和NOD—SCID小鼠的红细胞感染率均在d8达到峰值（86．4％和72．5％）。红细胞感染率达到峰值后，BALB／c小鼠的红细胞感染率迅速下降，免疫抑制BALB／c小鼠的红细胞感染率缓慢降低．SCID小鼠和NOD—SCID小鼠的红细胞感染率则出现震荡变化。感染的BALB／c小鼠的心、肝、脾、肺、肾、脑和骨髓等组织内均可观察到田鼠巴贝虫，虫体主要位于红细胞内，各组织内的红细胞感染率随外周血红细胞感染率的升高而增高。冷冻保存的虫种复苏后可感染健康BALB／c小鼠，末梢血中出现虫体的时间与新鲜含虫血液感染鼠的比较滞后2d．达到感染高峰的时间滞后1d。结论成功建立田鼠巴贝虫的小鼠模型．红细胞的感染情况与机体的免疫状态相关。

英文摘要：

Objective To establish the experimental animal model for the study of Babesia mocroti. Methods BALB/c mice, immunosuppressive BALB/c mice, SCID mice and NOD-SCID mice were inoculated with B. mocroti-infected red blood cells （RBC） by intraperitoneal injection respectively. After inoculation, thin blood smears were prepared every day, stained with Giemsa staining and examined for the presence of parasitemia. Three mice were dissected to examine the infectiosity in bone marrow, brain, spleen, heart, lung, kidney and liver tissues. The infection rate of erythrocytes in different tissues was recorded, and the relationship between the infectiosity of tissues and infection rate in peripheral blood was analyzed. Blood samples infected with B. microti were preserved in liquid nitrogen with dimethyl snlfoxide （DMSO） for 2 months. The thawed parasitized blood was injected into the BALB/c mice by same route and the para- sitemia was monitored. Results The four kinds of mice were all infected by B. microti with parasitemia. The percentage of parasitized red blood cells from peripheral blood were 82.4% （BALB/c mice, d7）, 73.2%（immunosuppressive BALB/c mice, dS）, 86.4% （SCID mice, d8） and 72.5% （NOD-SCID mice, d8） at the maximum, respectively. Para- sitemia decreased rapidly in BALB/c mice, whereas decreased slowly in immunosuppressive BALB/c mice. Only the parasitemia in SCID mice and NOD-SCID mice decreased significantly and tended to picking up again. The parasites were observed in RBCs from bone marrow, brain, spleen, heart, lung, kidney and liver tissues. The infection rate of erythro-cytes in tissues increased with an increase of infection in peripheral blood. After cryopreservation, the parasites proliferated in BALB/c mice. Parasitemia appeared after inoculation with frozen infected blood two days later than that of fresh infected blood. The infection rate reached its peak after inoculation with frozen infected blood one day later than that of fresh infected blood. Conclusion The experimental ani