gdh基因在猪链球菌中的分布及重组GDH的抗原性研究

目的了解谷氨酸脱氢酶基因(gdh)在不同血清型猪链球菌(S.suis)中的分布情况,分析重组谷氨酸脱氢酶(GDH)的抗原性,为其应用于S.suis感染诊断和疫苗研究提供实验数据。方法应用PCR方法检测不同血清型S.suis中的gdh;利用45 kD重组GDH制备多克隆抗体,Western blot方法分析S.suis各血清型菌株与多克隆抗体的反应以及实验感染S.suis2型的猪血清与重组GDH的反应情况。结果在S.suis35个血清型标准株中,除了22、26、27、29、32及34型以外,其余包括1、2、1/2、7、9和14型在内的29个血清型、61株国内外S.suis2型分离株全部扩增出目的条带。用重组GDH免疫小鼠,在小鼠血清中均检测到抗GDH的抗体;Western blot结果显示,全部被检菌株与抗GDH血清反应均有单一特异性反应条带,6份实验感染猪血清均能与重组GDH产生反应条带。结论重组GDH具有免疫原性和反应原性,该蛋白有可能作为建立诊断试验的候选抗原,为进一步开展相关的血清学诊断方法和疫苗研究奠定基础。

Distribution of glutamate dehydrogenase gene in Streptococcus suis and the antigenicity of its gene product

To understand the distribution of glutamate dehydrogenase(GDH)gene(gdh)in different serotypes of Strptococcus suis and to analyze the antigenicity of its gene product to be used in diagnosis and vaccine preparation,a total of 96 strains of S.suis including 35 reference strains of S.suis with different serotypes,58 strains of S.suis serotype 2 isolated from Chinese and 3 strains of S.suis serotype 2 isolated abroad was investigated by means of PCR assay.The polyclonal antibodies against 45 kDa recombinant GDH were prepared as usual,Western blot assay was used to analyze the reactivity of S.suis with different serotypes with polyclonal antibodies as well as the reactions between the serum of pigs infected with S.suis serotype 2 and the reconbinant GDH.It was found that in these 35 strains of S.suis with different serotypes,except the serotypes 22,26,27,29,32 and 34,the others including serotypes 1,2,1/2,7,9 and 14,showed target bands in PCR assay in these 29 strains of serotypes.In addition,target bands could be demonstrated in 58 strains isolated from Chinese and 3 strains isolated abroad.The antibodies against GDH could be detected in serum of mice imminized with recombinant GDH.As demonstrated by Western blot assay,a specific single band formed by the reaction between all the bacterial strains and the anti-GDH serum could be found,and 6 serum samples of pigs experimentally infected reacted with the recombinant GDH to form the reaction bands.From these observations,it is evident that the recombinant GDH proceeds excellent antigenicity and immunnoreactivity with potentially diagnostic and epidemiologic application as well as for the development of vaccine.