Seroprevalence of antibodies to Borrelia burgdorferi sensu lato in healthy adults from western Norway: risk factors and methodological aspects

The aim of this study was to assess the seroprevalence of antibodies to Borrelia burgdorferi sensu lato in a healthy adult population from Sogn and Fjordane county in western Norway by different assays. Sera from 1213 blood donors at four different blood banks were analysed in Enzygnost Lyme link VlsE/IgG (IgG), Enzygnost Borreliosis IgM (IgM), and Immunetics C6 Lyme ELISA kit (C6). Sera showing positive or grey‐zone reactivities were further examined with Borrelia‐EUROLine‐RN‐AT IgG blot and Borrelia‐EUROLine‐RN‐AT IgM blot. The seroprevalences were 9.6%, 8.2%, 8.4%, 6.4% and 5.7%, respectively. The seroprevalence for IgG was lower in the eastern part of the county and in owners of pet animals. It was higher in men, and increased with age and number of tick bites. C6 and IgG gave comparable results. IgM only was found in 4.5%, more often in women, did not increase with age, and showed no relationship with geography, and 56.4% were positive in IgM blot. In conclusion, antibodies to B. burgdorferi s.l. are common in blood donors in western Norway. The results may be used for evaluation of predictive values of test results in patients, as well as a basis for test algorithms in the laboratory.     

中国莱姆病螺旋体FP1外膜蛋白A的克隆表达及其抗原性的初步研究

目的　克隆并表达中国莱姆病螺旋体阿弗西尼疏螺旋体基因种参照菌株FP1的外膜蛋白A(OspA) ,并对其抗原性进行初步研究和基因序列分析 ,为研制中国莱姆病疫苗提供资料。方法设计引物 ,用聚合酶链反应 (PCR)从莱姆病螺旋体FP1全基因组DNA中扩增出OspA编码基因 ,经酶切、连接 ,插入原核表达载体pET 11d ,构成重组质粒pET 11d ospA ,在大肠杆菌BL2 1(DE3)中表达 ,表达产物用SDS PAGE、Westernblot分析 ,并进行基因序列测定。结果　rOspA在宿主菌内获得高效、稳定表达 ;相对分子质量 (Mr)约为 31× 10 3,Westernblot显示其与抗OspA的多抗有良好的免疫反应性 ;经测序显示该rOspA的基因片段长度为 783bp ,编码 2 6 1个氨基酸 ,与欧洲标准菌株Pko和瑞士标准菌株VS4 6 1的OspA的DNA碱基序列比较 ,同源性均为 94 %。结论　在国内首次成功地对中国莱姆病螺旋体阿弗西尼疏旋体基因种的代表菌株FP1的OspA基因进行了克隆和表达。并且证实rOspA有良好的抗原性 ,可进一步对其免疫保护性进行研究 ,以便为研制有效的莱姆病疫苗提供数据。     

中国莱姆病螺旋体PD91外膜蛋白A的克隆表达及免疫保护性的初步研究

目的：克隆并表达中国莱姆病螺旋体Borrelia garinii基因型代表菌株PD91的外膜蛋白A(OspA)，并对其免疫保护性进行 初步研究，为进一步研制莱姆病疫苗提供基础。方法：用聚合酶链反应（PCR）从莱姆病螺旋体PD91全基因组DNA中将OspA基因调出，插入原核表达载体P42，在大肠杆菌BI21(DE3)中表达，表达产物用SDS-PAGE、Western blot分析，并进行基因序列测定。用重组OspA（rOspA）免疫新西兰家兔，用间接免疫荧光（IFA）检测其血清特异性抗体（IgG），并进行体外中和试验，从而对其免疫保护性有初步的了解。结果：rOspA在宿主菌内表达高效、稳定；Western blot 显示其与抗OspA的多抗有较好的免疫反应性；用rOspA免疫新西兰家兔后，其血清抗体（IgG）效价显著升高（32倍），体外中和试验表明，每毫升兔抗rOspA血清可杀来源10^5个莱姆病螺旋体。结论：在国内首次成功地对中国莱妈病螺旋体Borrelia garinii基因型的OspA基因进行了克隆和表达。ROspA有较好的免疫保护性，可作为多价莱姆病疫苗的一种成分。