摘要
通过构建标记疫苗株来解决流产布氏杆菌(B.abortus)鉴别诊断方面的缺陷,本研究以bp26基因作为重组靶位点,S19为亲本,利用bp26基因ORF外侧序列作为同源重组序列,卡那霉素抗性基因(Kanr)为抗性筛选标记,通过双交叉重组筛选获得bp26基因缺失突变的重组S19株,命名为S19-△26。小鼠感染结果表明,突变株S19-△26的残留毒力与亲本株S19相比较没有发生明显改变,康复时间约为15周,突变株S19-△26、亲本株S19和B.abortus强毒株S544接种小鼠后的第3周能检测出"O"抗原的特异性抗体,而第6周开始S19和S544接种小鼠BP26特异性抗体明显升高,S19-△26接种的小鼠一直没检测到BP26特异性抗体。小鼠免疫保护试验显示,脾脏分离CFU数比空白对照要低3log10,S544攻击后脾脏细菌分离数表明突变株具有与亲本疫苗株免疫保护性无明显差异。结果表明,S19-△26免疫能够通过血清学方法与野生型B.abortus感染后的免疫反应相区别,具备作为标记疫苗的潜力。
Brucella abortus strain S19 played an important role in preventing and monitoring brucellosis with high protective rate. S19-△26, a Mutant bp26 gene of B. abortus S19 strain was constructed by replacing the bp26 gene of attenuated S19 with kanamycin resistence gene. Compared with S19, mutant S19-△26 possessed the same recover time （15 weeks） and residual virulence in mice, However it did not induce anti-bp26 antibody production in Mice, which would differentiate animals infected with S19-△26 from those infected by S19 and S544. The mutant S19-△26 possesses the same protective ability as S19, which could reduce CFU number of strain S544 infection in mice by 3log10. Altogether, these results indicate that B. abortus S19-△26 could be a promising vaccine strain in preventing brucellosis.
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2009年第11期887-891,913,共6页
Chinese Journal of Preventive Veterinary Medicine
基金
国家863计划(20060102Z449)
