伴放线放线杆菌血清型b菌株中磷酸胆碱的检测

Detection of the phosphorylcholine epitope in Aggregatibacter actinomycetemcomitans serotype-b strains

目的检测伴放线放线杆菌(Aggregatibacter actinomycetemcomitans,Aa)血清型b菌株细胞中是否存在磷酸胆碱。方法采用免疫荧光显微镜技术、狭线印迹法、十二烷硫酸钠-聚丙烯酰胺凝胶电泳和免疫印迹法等方法,用磷酸胆碱特异性单克隆抗体TEPC-15作为检测抗体,检测12株Aa血清型b菌株中的磷酸胆碱。结果通过狭线印迹法在Aa中可以检测到磷酸胆碱,12个血清型b菌株中,5个菌株为磷酸胆碱阳性,占总数的41.7%;免疫荧光显微镜观察结果提示该结构位于Aa的表面,聚丙烯酰胺凝胶电泳免疫印迹法显示,磷酸胆碱附着的结构分子量大小约为9 kDa,免疫荧光显微镜和电泳免疫印迹法的阳性菌与狭线印迹法的阳性菌相同。结论 Aa血清型b菌株细胞中可以检测到磷酸胆碱,该结构可能位于Aa的表面。

Objective To detect the possible occurrence of the phosphorylcholine（ChoP） epitope in Aggregatibacter actinomycetemcomitans（Aa） serotype b strains.Methods Immunofluorescence microscopy,slot blot,and immunoblot were applied to detect expression of the ChoP in 12 Aa serotype b strains by using mouse anti-ChoP monoclonal antibody TEPC-15 as the primary antiserum and goat anti-mouse IgA as the secondary antiserum.Results Slot blot results revealed positive reactions in 5/12（41.6%） of strains tested.The ChoP could be detected by immunofluorescence microscopy implied that ChoP may be on the surface of Aa.Immunoblot results showed that ChoP on a structure of 9 kDa.The 5 positive strains could be detected by immunofluorescence,slot blot,and immunoblot simultaneously and 7 negative strains were all negative by all 3 methods.Conclusion Phosphorylcholine could be detected in Aa serotype b strains.And the epitope may be on a surface structure of 9 kDa.