本发明涉及一种2型猪链球菌salKR基因敲除突变株及其制备方法和应用。所述突变株05ZYH33ΔsalKR，保藏号为CGMCC No.2259。其制备方法为：利用同源重组技术将S.suis 2野生株05ZYH33染色体上PAI<sub>89K</sub>毒力岛中的二元信号转导系统SalK/R进行基因敲除，经PCR鉴定和Southern杂交证实，确定所获得的菌株为基因敲除突变株，命名为05ZYH33ΔsalKR。用本发明所述突变株进行动物实验，其结果对实验动物无任何危害，所述突变株与野生株全基因组序列相似性很大，适合用于疫苗研究与生产。
The invention relates to a gene knock-out mutant of Streptococcus suis type 2 salKR and the preparation method and the application thereof. The mutant 05ZYH33 delta salKR has the preservation number of CGMCC No.2259. The preparation method comprises a step of subjecting a dual signal transduction system in PAI89K pathogenicity island on chromosome 05ZYH33 of wild S.suis 2 strain to gene knock-out by homologous recombination technology. Verified by PCR identification and Southern blotting, the obtained stain is gene knock-out mutant named as 05ZYH33 delta salKR. Animal test shows that the mutant has no harm to animals, and the whole genome sequence of the mutant has large similarity to that of the wild strain, so that the mutant is suitable for research and production of vaccines.