Spontaneously released Neisseria meningitidis outer membrane vesicles as vaccine platform: production and purification

Outer membrane vesicles (OMVs) are nanoparticles produced by Gram-negative bacteria that can be used as vaccines. The application of OMVs as vaccine component can be expanded by expressing heterologous antigens on OMVs, creating an OMV-based antigen presenting platform. This study aims to develop a production process for such OMV-based vaccines and studies a production method based on meningococcal OMVs that express heterologous antigens on their surface. As a proof of concept, the Borrelia burgdorferi antigens OspA and OspC were expressed on Neisseria meningitidis OMVs to create a concept anti-Lyme disease vaccine. Production of OMVs released in the culture supernatant was induced by high dissolved oxygen concentrations and purification was based on scalable unit operations. A crude recovery of 90 mg OMV protein could be obtained per liter culture. Expressing heterologous antigens on the OMVs did result in minor reduction of bacterial growth, while OMV production remained constant. The antigen expression did not alter the OMV characteristics. This study shows that production of well characterized OMVs containing heterologous antigens is possible with high yields by combining high oxygen concentrations with an optimized purification process. It is concluded that heterologous OMVs show potential as a vaccine platform.     

中国6省莱姆病螺旋体主要宿主动物鼠的初步调查

目的了解中国吉林、山西、甘肃、青海、贵州、湖南6省林区莱姆病螺旋体宿主动物鼠的感染情况。方法在每个省各选取两个采样点进行捕鼠,采用病原分离培养和巢式PCR方法对野鼠的脾脏、肾脏和膀胱进行了病原学检测。并通过基因测序方法确定基因型。结果从贵州黑线姬鼠中分离到了2株莱姆病螺旋体;从5省(贵州未检测到)野鼠的脾脏和/或肾脏中检查到了莱姆病螺旋体的特异片段,其中青海黄南(28.85%)和湖南石门(19.6%)两地标本的PCR阳性率较高,各地区阳性率的差异有统计学意义。通过序列同源性分析确定吉林、青海、甘肃和山西的基因型均为Borrelia garinii。湖南的基因型为Borreliavalaisiana。结论本次调查表明各地宿主动物鼠的感染状况不同,各地应根据具体情况进一步扩大调查以明确当地的主要宿主动物种类及携带病原体情况。     

Perineuritis in acute lyme neuroborreliosis

Perineuritis is an unusual cause of direct peripheral nerve injury. We describe the clinicopathologic features of a 56‐year‐old man with mononeuritis multiplex due to Lyme disease; sural nerve biopsy demonstrated florid perineuritis. Treatment with intravenous ceftriaxone resulted in marked neurologic improvement. This study supports the notion that perineuritis forms part of the pathogenesis in acute Lyme neuroborreliosis. Muscle Nerve, 2009     

Acute myelitis and Lyme disease

INTRODUCTION: Acute myelitis accounts for 4 to 5 percent of all cases of neuroborreliosis. In the literature, simultaneous spinal MRI and cerebrospinal fluid (CSF) investigations are presented for only 8 cases. We describe here 3 cases of acute Lyme myelitis. METHOD: In a cohort of 45 patients with neuroborreliosis, diagnosed between January 1998 and January 2005, 3 had acute myelitis. Clinical, biological and radiological data were studied. CASE REPORTS: The three patients had motor, sensorial and sphincter involvement. Extra-spinal involvement, such as fever and headache for one, facial nerve palsy for the second and subarachnoid hemorrhage for the third, was also noted. Pleocytosis varied from 10 to 520 white cells per mm3. Lyme serology was positive in CSF for all. Intrathecal anti-Borrelia antibody index was positive or intermediate for all three patients. Spinal cord MRI revealed a large hyperintense zone involving more than 3 vertebral segments. Myelitis was central, posterior or transverse in the axial plane. The clinical course was favorable after a three-week course of appropriate antibiotics. CONCLUSION: These 3 cases and the others from the literature show the diversity of the clinical and radiological features of acute myelitis: transverse, central or posterior myelitis. Thus, Lyme serology in CSF in indicated for patients presenting acute myelitis, particularly in endemic areas.     

Comprehensive seroprofiling of sixteen B. burgdorferi OspC: Implications for Lyme disease diagnostics design

Early diagnosis of Lyme disease (LD) is critical to successful treatment. However, current serodiagnostic tests do not reliably detect antibodies during early infection. OspC induces a potent early immune response and is also one of the most diverse proteins in the Borrelia proteome. Yet, at least 70% of the amino acid sequence is conserved among all 21 known OspC types. We performed a series of comprehensive seroprofiling studies to select the OspC types that have the most cross-reactive immunodominant epitopes. We found that proteins belonging to seven OspC types detect antibodies from all three infected host species regardless of the OspC genotype of the infecting strain. Although no one OspC type identifies all seropositive human samples, combinations of as few as two OspC proteins identified all patients that had anti-OspC antibodies.     

Touchdown PCR检测野生中缅树鼩伯氏疏螺旋体感染

目的用Touchdown PCR检测野生中缅树鼩的伯氏疏螺旋体感染。方法从昆明及其周边地区捕获30只野生中缅树鼩,乙醚深度麻醉后处死,取内脏-30℃保存备用。用总DNA提取试剂盒提取组织总DNA,用紫外可见光分光光度计测定样品的DNA含量,用热启动Touchdown PCR技术检测野生中缅树鼩的伯氏疏螺旋体flaB基因。对PCR产物做凝胶电泳,凝胶成像仪观察并照相。结果Touchdown PCR有良好的特异性和敏感性。实验重复3次,结果一致,野生树鼩的伯氏疏螺旋体DNA阳性率为63．33％（19／30）。结论野生树鼩存在伯氏疏螺旋体感染,并且感染率较高。     

中国西北部分地区人群莱姆病血清流行病学调查

莱姆病是由莱姆病螺旋体引起的一种自然疫源性疾病.我国于1986年首次在黑龙江省海林县林区发现该病~([1]),后证实莱姆病在国内分布相当广泛~([2]).为了解我国西北部分地区林区人群感染情况,在新疆、甘肃、宁夏、陕西4省区的林区进行选点调查.     

蛋白质芯片对莱姆病患者血清抗鞭毛蛋白抗体的检测分析

目的 探讨蛋白质芯片在莱姆病诊断中的价值。方法 用伯氏疏螺旋体鞭毛蛋白包被N-羟基琥珀酰亚胺修饰的芯片对82例神经性莱姆病、35例环形红斑莱姆病患者和44例正常人对照血清鞭毛蛋白特异性IgM 和 IgG抗体进行检测，并与酶联免疫吸附（ELISA）和蛋白质印迹方法比较。 结果 神经性莱姆病患者血清IgM和IgG抗体水平均高于正常人对照组（P < 0.001）。蛋白质芯片检测神经性莱姆病患者IgM抗体阳性率为76.8%，ELISA检测为63.4%，两种方法检测的阳性率比较，差异有统计学意义（P < 0.05）。蛋白质芯片、ELISA和蛋白质印迹联合检测使环形红斑莱姆病患者IgM和IgG抗体阳性率有所提高。对蛋白质芯片和ELISA两种方法检测的神经性莱姆病、环形红斑莱姆病患者IgM抗体结果分别进行线性分析，发现两种检测方法具有相关性。结论 鞭毛蛋白包被N-羟基琥珀酰亚胺修饰的蛋白质芯片可用于莱姆病临床诊断。     

江苏省蜱及其携带莱姆病螺旋体初步调查

目的：了解我省莱姆病主要传播媒介蜱的种类、分布、消长及其携带莱姆病螺旋体情况。方法：在山区、林区用布旗法及动物体外捕捉法收集蜱，并进行病原体分离。结果：我省长江南北均有蜱存在，隶属１科２属４种；蜱密度有明显季节性，４月初出现，５～６月为高峰，８月逐渐下降，至１０月下旬消失；蜱研磨培养２５组５０管，３个月定期镜检，未发现莱姆病螺旋体。结论：我省蜱的莱姆病传播媒介和贮存宿主作用尚不能定论