钩端螺旋体疫苗菌种分子遗传质量控制方法的建立

Development of a method for molecular genetic quality control of leptospiral vaccine strains

目的建立钩端螺旋体(简称钩体)疫苗菌种分子遗传质量的控制方法。方法采用PCR扩增7株钩体的7种管家基因序列,进行多序列位点分析(multilocus sequence typing,MLST),并系统评价不同传代次数菌种的分子遗传稳定性。同时组织协作标定,验证MLST方法用于疫苗菌种分子遗传质控的适用性。结果 7种钩体疫苗株呈现7种不同序列基因型。疫苗菌种在动物增毒前、后及在体外连续传代20代,细菌MSLT序列基因型未发生改变,证明钩体疫苗菌种具有良好的分子遗传稳定性。协作标定研究结果也表明,该方法具有良好的重复性,且结果易于标准化。结论建立了评价钩体疫苗菌种的分子遗传质控方法,疫苗菌株MLST序列基因型可作为一项候选的质量控制标准,完善了当前疫苗质控监管体系。

Objective To develop a method for molecular genetic quality control of leptospiral vaccine strains. Methods Seven housekeeping gene sequences were amplified from each vaccine strain by PCR and subjected to multilocus sequence typing（MLST）. The molecular genetic stability of various passages of vaccine seeds were evaluated. Meanwhile,collaborative study was conducted to assess the applicability of MLST to molecular genetic quality control of vaccine strains. Results The seven vaccine strains showed different MLST genotypes. However,the MLST genotype of each strain showed no change after in vivo and in vitro subculture for 20 passages,suggesting that the strains were genetically stable. Collaborative study also demonstrated good reproducibility of the method, and the result was easy to be standardized. Conclusion A method for molecular genetic quality control of leptospiral vaccine strains was developed. It is suggested that MLST sequence genotyping might be used as a potential standard of quality control. These data improved the current quality control system.