评价牛型布鲁氏菌疫苗免疫保护力BALB/c鼠模型的建立

为建立评价流产布鲁氏菌疫苗株免疫保护力的小鼠模型,选取6周龄雌性BALB/c小鼠为试验动物,随机分为3组(n=40):A19免疫攻毒组、非免疫攻毒组和PBS对照组。A19免疫组腹腔接种BALB/c鼠A19 5.0×10⁴ CFU,非免疫攻毒组和PBS对照组均接种PBS液0.2 mL。免疫后45 d,A19免疫攻毒组和非免疫攻毒组BALB/c鼠以3.0×10⁴ CFU剂量的2308强毒株攻击,攻毒后15和45 d分别剖杀小鼠,取小鼠脾脏称重、细菌分离、病理组织学检测。结果表明,攻毒后15 d,A19免疫攻毒组与未免疫攻毒组和PBS对照组之间克脾指数差异显著(P<0.05);攻毒后45 d,A19免疫攻毒组与PBS对照组的克脾指数差异不显著(P>0.05),与未免疫攻毒组克脾指数差异显著(P<0.05);免疫攻毒组的小鼠组织病理变化明显轻于未免疫攻毒组。结果表明,用BALB/c鼠为试验动物,以A19为疫苗参考株建立动物实验模型可以应用于牛型布鲁氏菌疫苗免疫保护力评价。

Establishment of BALB/c Mouse Model for Evaluation of Protective Immunity in Brucella abortus

The mouse model for evaluation of protective immunity was established in Brucella abortus. 6-week-old female BALB/c mice were randomly divided into 3 groups (n=40). The mice were each injected intrap eritoneally with 5.0?10⁴ CFU of strain A19 (A19-challenge-group), and another two unimmunized groups served as unimmunized-challenge-group and PBS group with 0.2 mL of PBS.At the 45-dayspost-immunization, all of mice in A19 group and challenged group were each challenged with 3.0?10⁴ CFU of the same subtype 2308 strain.Fifteen days postchallenge, mice were killed and their spleens were removed, weighed, Brucella isolation and pathological changes of organs could be detected in the mice. The results showed that the Brucella load of gram of spleen in A19-challenge-group and unimmunized-challenge-group had a significant difference than the PBS control group (P<0.05). At the 45-day-postchallenge, the result of Brucella load of gram of spleen had no significant difference between the A19-challenge-group to the PBS control group (P>0.05). However, it had significant difference in A19-challenge-group than the unimmunized-challenge-group. The mice of pathological changes in A19-challenge-group had significantly lighter than that of unimmunized-challenge-group (P<0.05). These results indicated that BALB/c mouse model could be applied to evaluate the protective immunity in Brucella abortus.