从野兔体内分离出莱姆病螺旋体

1992年6月在湖南靖州县排牙山林场调查莱姆病的动物宿主和蜱,从华南野兔的肾、膀胱中分离一株莱姆病螺旋体C_(s3),C(s4),与抗B_(31)IgG抗体反应阳性,与单克隆抗体反应似国内大多数菌种,与美国B_(31)稍有差别。野兔可能是我国南方莱姆病的重要宿主,首次证实湖南是该病的自然疫源地。     

基于不同基因型的中国莱姆病螺旋体菌株标准化研究

目的 建立莱姆病螺旋体中国株5种基因型(巴伐利亚疏螺旋体、伽氏疏螺旋体、阿弗西尼疏螺旋体、狭义伯氏疏螺旋体和扬子疏螺旋体)的标准菌株,为菌株鉴定、诊断试剂和疫苗研发提供基础。方法 依据《病原微生物菌(毒)种国家标准株评价技术标准》(WS/T 812-2022),针对中国莱姆病螺旋体5种主要基因型,选取5株菌株(PD91、MD86、FP1、CS4和QXS13)。首先接种到BSKⅡ培养基中培养,暗视野显微镜下观察菌株的形态学特点。提取全基因组DNA,聚合酶链式反应扩增莱姆病螺旋体5S～23S rRNA基因间隔区并测序,将每株菌株不同代次培养物的产物序列分别进行比对分析。随后使用多位点序列分析(MLSA)方法鉴定菌株基因型,同时将不同代次菌株MLSA聚类分析结果进行比对,验证菌株遗传学稳定性。通过Illumina NovaSeq平台进行全基因组测序分析菌株基因组特征。结果 5株菌株均具有莱姆病螺旋体典型形态学特征。经特异性基因检测及MLSA分型鉴定,依次为巴伐利亚疏螺旋体(PD91),伽氏疏螺旋体(MD86),阿弗西尼疏螺旋体(FP1),狭义伯氏疏螺旋体(CS4)和扬子疏螺旋体(QX-S13...     

中国莱姆病螺旋体尿素酶抗原的初步研究

莱姆病螺旋体（即伯氏疏螺旋体，Ｂｏｒｅ－ｌｉａｂｕｒｇｄｏｒｆｅｒｉｓｅｎｓｕｌａｔｏ）是一种新发现的莱姆病的病原体［１］。调查研究发现莱姆病螺旋体从动物肾脏和膀胱的分离率高［２～４］。因此，我们推测莱姆病螺旋体是否象钩端螺旋体、幽门螺杆菌一样具有尿...     

莱姆病螺旋体检测技术的进展

1 莱姆病螺旋体简介 莱姆病（Lyme Disease,LD）最早发现于美国的Lyme镇并由此得名,莱姆病是由蜱传播的一种自然疫源性、人畜共患疾病,通过肩突硬蜱感染人体宿主,可引起多系统器官损害,游走性红斑、神经炎、关节炎、心肌炎等.1982年Burgdorfer W等人成功从肩突硬蜱（Ixodes ricinus）中分离出莱姆病病原体——螺旋体1,螺旋体感染通常是开始于肩突硬蜱幼虫阶段,     

莱姆病螺旋体和森林脑炎病毒混合感染的误诊

圣彼得堡军医学院１９９３～１９９６年收治莱姆病和森林脑炎共１２９２例，其中莱姆病占８３．５％，森林脑炎占１２．７％，莱姆病合并森林脑炎４９例，占３．８％，其中男２３例，女２６例；年龄１６～６５岁。由于这两种疾病有相同的流行病学前提，有蜱叮咬史和森林内...     

创伤弧菌感染的致病机制研究现状

创伤弧菌是弧菌属低度嗜盐菌,自然生存于近海和海湾的海水和海底沉积物中。国外有关创伤弧菌感染的临床报道以及研究逐渐增多,然而,在国内对创伤弧菌感染脓毒血症病例报道不多。创伤弧菌可通过进食生的牡蛎穿过胃肠道黏膜或通过破损的皮肤接触海水入血而感染,并在短时间内出现败血症和蜂窝组织炎、出血性大疱,几天内病人便     

中国莱姆病螺旋体菌株OppA2基因中人B细胞表位多态性分析

目的 研究中国莱姆病螺旋体菌株中OppA2基因及其人B细胞抗原表位区的序列多态性,了解不同地域OppA2的变化特征,为中国莱姆病的早期诊断提供线索和依据。 方法 选取59株莱姆病螺旋体分离株,PCR扩增其OppA2基因并测序后,结合3种基因型参考菌株序列,与免疫表位数据库（IEDB）中查询到的B细胞表位序列进行比对分析。 结果 中国莱姆病螺旋体中OppA2基因序列在Borrelia burgdorferi sensu strict（B.b.s.s）, Borrelia garinii（B.g）和Borrelia afzelii（B.a）3个基因型间存在明显的多态性。 但OppA2基因序列在B.b.s.s和B.a型内保守;在B.g型内存在异义突变。 B细胞表位改变主要发生在B.g基因型的亚簇2、亚簇3以及JC2-2分离株。 B.g基因型的亚簇2、亚簇3以及JC2-2菌株的296aa变异和亚簇3的295aa变异使3个B细胞抗原表位受影响;JC2-2菌株的372aa变异使1个B细胞抗原表位受影响;这些表位区的变异使部分B细胞表位序列（4/7,57.1%）呈现多态性。 结论 中国莱姆病螺旋体OppA2基因及其人B细胞抗原表位区在3个基因型间和B.g型内存在多态性;其中有3个B细胞抗原表位区（191～225aa、276～290aa和381～400aa）在B.b.s.s,B.g和B.a三种基因型内高度保守,可作为中国莱姆病早期诊断的候选抗原。      

神经莱姆病诊治进展

莱姆病(Lyme disease,LD)是由伯氏疏螺旋体(Borrelia burgdorferi)引起的一种多阶段、多系统的疾病,主要影响皮肤、心脏、关节和神经系统 [1].LD在北美、欧洲、亚洲不同地区包括中国、澳大利亚和非洲等都有报道 [2].LD的发病率在过去数十年里大幅增加,美国每年有超过25 000例新的确...     

金黄色葡萄球菌的致病和耐药机制研究进展

金黄色葡萄球菌(Staphylococcus aureus,SA)是近年来社区和医院感染的重要危险致病菌之一,其致病性强,感染率高,传播速度快,耐药性强,为疾病治疗带来了极大困难。SA可以产生包括各种外毒素、肠毒素、凝集因子、生物膜等在内的多种致病因子,并能够通过产生修饰酶、改变抗菌药物的作用靶点、降低细胞壁的通透性等不同机制的作用,对β-内酰胺类、大环内酯类、氟喹诺酮类、环脂肽、糖肽类、消毒剂等药物产生不同程度的耐药。本文就SA的致病机制、耐药机制和治疗策略作一综述,借以为临床诊断和治疗用药提供思路和依据。     

常见支原体的临床危害及致病机制

支原体在自然界分布广泛，其中一些致病性支原体，因为缺少有效的治疗措施和疫苗，广泛成为世界公共卫生，畜牧生产的一个显著问题，引起社会经济损失。因此，对支原体感染的临床症状及其分子生物学的深入理解尤为重要。     

Sexual transmission of Lyme disease: challenging the tickborne disease paradigm

Lyme disease caused by the spirochete Borrelia burgdorferi has become a major worldwide epidemic. In this article, we explore the clinical, epidemiological and experimental evidence for sexual transmission of Lyme disease in animal models and humans. Although the likelihood of sexual transmission of the Lyme spirochete remains speculative, the possibility of Lyme disease transmission via intimate human contact merits further study.     

In-vitro and in-vivo antibiotic susceptibilities of Lyme disease Borrelia isolated in China

The antibiotic susceptibilities of seven Borrelia burgdorferi sensu lato isolates from Ixodes persulcatus in China were examined by in-vitro microdilution minimum inhibition concentration (MIC) and macrodilution minimum bactericidal concentration (MBC) methods. All isolates tested were susceptible to amoxicillin, erythromycin, and minocycline. The MICs of these drugs for the Chinese isolates were 0.025–0.1 μg/ml, <0.012–0.05 μg/ml, and <0.012–0.05 μg/ml, respectively. The MBCs were 0.1–0.39 μg/ml, <0.012–0.2 μg/ml, and 0.025–0.39 μg/ml, respectively. The in-vivo antimicrobial susceptibilities of the Chinese Borrelia isolates to two test drugs, amoxicillin and minocycline, were evaluated using ddY mice. Mice were infected by subcutaneous inoculation into the right hind footpad. When infection was confirmed, the mice were treated by subcutaneous injection of the test drugs into the back. Amoxicillin and minocycline, which possessed high in-vitro activities against Lyme disease Borrelia, provided good protection against borreliosis in this animal model. Higher doses of these drugs resulted in elimination of the Lyme disease spirochete from all animals receiving this course of treatment. The 50% curative doses (CD₅₀) of amoxicillin and minocycline were 8.7 mg/kg and 3.1 mg/kg, respectively. This suggested that amoxicillin and minocycline could be useful for the treatment of Chinese Borrelia infection. Received: July 13, 1998 / Accepted: November 17, 1999     

吉林地区伯氏疏螺旋体OSPA的克隆及免疫性的初步研究

目的克隆吉林地区莱姆病螺旋体分离株外膜蛋白A(OSPA),并对其免疫性进行初步研究,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)从吉林地区莱姆病螺旋体分离株的全基因组DNA中将OSPA基因调出,插入载体pCDNA3.1( )中,构建重组质粒pCDNA3.1( )-OSPA,用重组pCDNA3.1( )-OSPA质粒免疫C57小鼠,用ELISA法检测其血清特异性抗体,从而对其免疫性有初步的了解。结果pCDNA3.1( )-OSPA重组质粒构建成功,用pCDNA3.1( )-OSPA重组质粒免疫C57小鼠,在其血清中可检测到特异性抗体。结论成功地对吉林地区莱姆病螺旋体分离株的OSPA基因进行了克隆,OSPA有较好的免疫原性,可作为莱姆病疫苗的一种有效成分。     

西北4省区蜱虫自然感染3种病原体的分子流行病学研究

目的 了解西北4省区蜱虫自然感染莱姆病螺旋体、土拉弗氏菌和Q热立克次体的情况.方法 采用布旗法收集西北地区内的蜱标本进行分子生物学检测.结果 文献调研显示:西北地区已报道的虫媒疾病共有15种.西北地区内共采集蜱标本2 460只,涉及11个不同蜱种.共有304只蜱标本检测发现莱姆病螺旋体,75只感染土拉弗菌,200只感染Q热立克次体,3种病原体在4个调查点内均存在.共采集到西北地区内当地人群血清725份,共有183份血清存在目标抗体,进一步证实调查疾病的存在.结论 证实西北四省区存在3种蜱媒疾病在,对预防控制具有重要意义.     

Evaluation of molecular methods for detection of Borrelia burgdorferi senso lato in ticks

Borrelia burgdorferi sensu lato (s. l.), the agent of Lyme disease, is distributed widely worldwide. A large number of polymerase chain reaction (PCR) methods have been developed and used for detection of B. burgdorferi s. l. However, there is a lack of a reference standard because of the genetic diversity of the B. burgdorferi s. l. complex. In this study, 4 PCR methods, based on the OspA, flagellin, rrs, and P66 genes, for detection of B. burgdorferi s. l. were evaluated by detection of genomic DNA from 3 reference genospecies and tick samples. The sensitivity of the PCR methods was analyzed using serially diluted gDNA from B. afzelii (Bo23), B. burgdorferi sensu stricto (B31), and B. garinii (PBi). The performance of the PCRs was evaluated by detection of the gDNA of 543 ticks. The results showed that the PCRs targeting the OspA gene, fla gene, rrs gene, and P66 gene detected 37 (6.8%), 74 (13.6%), 16 (2.9%), and 14 (2.6%) tick samples, respectively. The PCR targeting the fla gene was the most sensitive method for the detection of B. burgdorferi s. l.     

Treatment of infection caused by Borrelia burgdorferi sensu lato

Borrelia burgdorferi sensu lato (Bbsl) infections, which are transmitted by Ixodes ticks, cause a wide variety of clinical manifestations and are of public health importance in parts of North America, Europe and Asia. A literature review of pertinent articles published up untill July 6th 2010 was performed on the use of antimicrobials in the treatment and prevention of Bbsl infections. The clinical outcome with 10-28 days of antibiotic treatment is generally excellent, but in view of the experience with other infections, future studies might address whether the duration of antibiotic therapy could be shortened.     

Comparison of five diagnostic modalities for direct detection of Borrelia burgdorferi in patients with early Lyme disease

Lyme disease, the most commonly reported tick-borne infection in North America, is caused by infection with the spirochete Borrelia burgdorferi. Although an accurate clinical diagnosis can often be made based on the presence of erythema migrans, in research studies microbiologic or molecular microbiologic confirmation of the diagnosis may be required. In this study, we evaluated the sensitivity of 5 direct diagnostic methods (culture and nested polymerase chain reaction [PCR] of a 2-mm skin biopsy specimen, nested PCR and quantitative PCR (qPCR) performed on the same 1-mL aliquot of plasma and a novel qPCR-blood culture method) in 66 untreated adult patients with erythema migrans. Results of one or more of these tests were positive in 93.9% of the patients. Culture was more sensitive than PCR for both skin and blood, but the difference was only statistically significant for blood samples (P<0.005). Blood culture was significantly more likely to be positive in patients with multiple erythema migrans skin lesions compared to those with a single lesion (P=0.001). Positive test results among the 48 patients for whom all 5 assays were performed invariably included either a positive blood or a skin culture. The results of this study demonstrate that direct detection methods such as PCR and culture are highly sensitive in untreated adult patients with erythema migrans. This enabled microbiologic or molecular microbiologic confirmation of the diagnosis of B. burgdorferi infection in all but 4 (6.1%) of the 66 patients evaluated.     

Effectiveness of antimicrobial treatment against Borrelia burgdorferi infection in mice.

Although antimicrobial agents are effective therapy for early Lyme disease, optimal treatment schedules have not been conclusively established. The efficacy of various dosages of eight antibiotics used for borreliosis treatment was evaluated for C3H/HeNCrIBR mice, which reproducibly develop persistent infection, arthritis, and carditis when inoculated with Borrelia burgdorferi. Amoxicillin-clavulanic acid, ceftriaxone, and high-dose penicillin G effectively eliminated infection and disease. Oxytetracycline, doxycycline, chloramphenicol, erythromycin, and azithromycin failed to cure infected mice. There was a correlation between peak serum antibiotic concentrations in mice, as determined by agar well diffusion bioassays, and therapeutic levels in humans. When experimentally inoculated mice were treated at 1 week postinfection with ceftriaxone (16 mg/kg of body weight twice daily for 5 days) and monitored for up to 90 days, all treated mice were free of spirochetes and had no gross or histologic lesions. This antibiotic regimen at days 7 to 11 postinoculation eliminated the spirochetes so that there were no relapses during the 90-day observation period. For experimentally inoculated mice treated with ceftriaxone at 7 or 14 days postinfection, arthritis, carditis, and infection were eliminated. When treatment began at 30 and 90 days after inoculation, infection and active cardiac and arthritic lesions were eradicated; however, residual mild synovitis and vasculitis persisted in some mice. In comparison with inoculated, untreated mice, ceftriaxone therapy at 7, 14, 30, and 90 days postinfection abrogated the development of antibody titers against B. burgdorferi. Having the potential to determine the presence of the spirochete through culture and histologic lesions makes the B. burgdorferi-inoculated C3H mouse model a valuable adjunct in evaluating chemotherapeutic options for Lyme disease.     

Epidemiology and diagnosis of Lyme borreliosis

The multisystem disease Lyme borreliosis is the most frequent tick‐transmitted disease in the northern hemisphere. In Europe Lyme borreliosis is most frequent in Central Europe and Scandinavia (up to 155 cases per 100,000 individuals) and is caused by the species, B. burgdorferi sensu stricto, B. afzelii and B. garinii. The recently detected genospecies A14S may also play a role in skin manifestations. Microbiological diagnosis in European patients must consider the heterogeneity of borreliae for development of diagnostic tools. According to guidelines of the USA and Germany, serological diagnosis should follow the principle of a two‐step procedure (enzyme‐linked immunosorbent assay (ELISA) as first step, if reactive; followed by immunoblot). The sensitivity and standardization of immunoblots has been considerably enhanced by use of recombinant antigens (p100, p58, p41i, VlsE, OspC, DbpA) including those expressed primarily in vivo (VlsE and DbpA) instead of whole cell lysates. VlsE is the most sensitive antigen for IgG antibody detection, OspC for IgM antibody detection. At present, detection rates for serum antibodies are 20%–50% in stage I, 70%–90% in stage II, and nearly 100% in stage III Lyme disease. Detection of the etiological agent by culture or polymerase chain reaction (PCR) should be confined to specific indications and specialized laboratories. Recommended specimens are skin biopsy specimens, cerebrospinal fluid (CSF) and synovial fluid. The best results are obtained from skin biopsies with culture or PCR (50%–70%) and synovial tissue or fluid (50%–70% with PCR). CSF yields positive results in only 10%–30% of patients except when the duration of symptoms is shorter than 2 weeks (50% sensitivity). Methods which are not recommended or adequately documented for diagnosis are antigen tests on body fluids, PCR of urine, and lymphocyte transformation tests.     

Double infection with tick borne encephalitis virus and Borrelia burgdorferi sensu lato

The limited information on co-infection with Borrelia burgdorferi sensu lato and tick-borne encephalitis (TBE) virus was a stimulus for presentation of two patients with well-defined double infection of the central nervous system. TBE virus and B. burgdorferi sensu lato infections are searched for in all patients with lymphocytic meningitis and/or meningoencephalitis admitted to our department. During the last ten years we identified two patients who had ELISA IgM and IgG antibodies to TBE virus in serum and a positive PCR result for TBE virus in cerebrospinal fluid as well as B. burgdorferi sensu lato isolated from cerebrospinal fluid. Intrathecal production of borrelial antibodies was not proven in either of the two patients. These findings show that in patients with acute lymphocytic meningitis originating in regions endemic for Lyme borreliosis and TBE, the possibility of concomitant infection should be considered.