用于评价小球隐孢子虫卵囊感染力的NMRI乳鼠模型

[目的 ]评价一定数量的小球隐孢子虫卵囊的感染力。 [方法 ]4日龄 NMRI乳鼠经口腔管饲法接种不同数量的卵囊 ,7d后处死乳鼠 ,取消化道幽门至肛门段并匀成悬液 ,取此悬液置载玻片上 ,石碳酸品红染色 ,相差显微镜查见卵囊的为被感染乳鼠。以各组被感染乳鼠百分率评价卵囊的感染力。 [结果 ]接种 15 0 0或 2 0 0 0的乳鼠均被感染 ;接种 10 0 0、 5 0 0、2 5 0、 10 0和 5 0个卵囊的乳鼠 ,感染率分别为 88%、 74%、 5 1%、 2 8%和 9.5 %。 [结论 ]NMRI乳鼠模型接种卵囊数在 15 0 0～5 0范围内 ,其接种量与感染率呈正相关。该模型可用于评价一定数量小球隐孢子虫卵囊的感染力。

A NMRI SUCKLING MOUSE MODEL FOR THE EVALUATION OF INFECTIVITY OF CRYPTOSPORIDIUM PARVUM OOCYSTS

Objective] To evaluate the infectivity of Cryptosporidium parvum oocysts in NMRI suckling mouse. [Methods] Four|day| old SPF NMRI suckling mice were inoculated with different amounts of oocysts by oral gavage. On day 7 after inoculation, suckling mice were sacrificed, and a suspension was prepared by homogenizing the intestinal tract from pylorus to anus. A mouse was considered infected when oocysts were found in smears of the intestinal content suspension stained with carbo lfuchsin solution. The infectivity of oocysts was evaluated as measured by the percentage of infected mice in each group.[Results] Mice receiving 1 500 or 2 000 oocysts were all infected. The percentages of infected mice were 88, 74, 51 and 28 respectively after ingestion of 1 000, 500, 250 and 100 oocysts. The percentage of infected mice was 9^5% after ingesting as few as 50 oocysts. [Conclusion] This model is convenient for evaluation of the infectivity of C.parvum oocysts.