禽大肠杆菌O_2、O_(78)及其耐药、融合菌株的外膜蛋白免疫研究

Immunogenicity of the outer membrane proteins of poultry-sourced Escherichia coli O_2 and O_(78), their antibiotics-resistant, and fusion strains

为了研究大肠杆菌O2、O78及其耐药、融合菌株外膜蛋白的免疫原性,用Sarkosyl处理和超速离心技术相结合的方法分别提取禽大肠杆菌强毒株O2、O78,耐药弱毒株O2(NorrChls)、O78(NorsChlr)及其融合双价弱毒株O2.78(NorrChlr)等5个菌株的外膜蛋白(OMPs),经SDS PAGE,结果均出现1条相同的相对分子质量在31000～43000之间的主要OMPs条带,表明5个菌株存在相同的OMPs成分.将3个耐药菌株的OMPs分别免疫小白鼠和鸡,结果均产生对O2、O78良好的同源及交叉免疫保护效果.用各耐药菌株的OMPs做包被抗原,ELISA方法都能交叉检测3个耐药菌株OMPs免疫鸡血清中IgG水平,且各IgG的消长曲线基本一致.

The aim of the present study was to evaluate the immunogenicity of the outer membrane proteins (OMPs) of virulent strains of E.coli O_2 and O_(78) isolated from poultry and their resistant strains O_2 (Nor^rChl^s),O_(78) (Nor^sChl^r), and resistant fusion strain O_(2.78)(Nor^rChl^r). The OMPs of the five strains were extracted by using sarkosyl-treatment plus ultracentrifugation and analyzed with SDS-PAGE. The results showed that the major OMP bands produced by the five strains were similar in size, between (31 000)-(43 000), indicating that they were of the same composition. The OMPs of three resistence strains could induce strong homologous and cross protective immunity in mice and chickens. Using OMPs extracted from the three resistant strains as coating antigen in the enzyme-linked immunosorbent assay (ELISA) to determine the elicited serum IgG titer against OMPs, it was shown that each of the OMPs could detect IgG against all the three OMPs and that the IgG level was similar.