淋病奈瑟菌分型研究进展

淋病奈瑟菌(简称淋球菌)是引起淋病的病原体。淋球菌的疫苗研究工作进展缓慢,迄今未研制出有效的疫苗;近年来,淋球菌耐药性逐年上升,多重耐药性淋球菌随之出现并广泛传播,使淋病的防治越来越困难。研究表明,淋球菌分型在淋病疫苗的研究、制定流行病学控制措施和淋病的治疗中均具有极其重要的意义。淋球菌的分型方法包括血清学分型、营养分型等传统分型方法和脉冲场凝胶电泳(PFGE)、随机扩增多态性DNA分型(ARPD)、opa分型、por分型、多位序列分型(MLST)等分子生物学分型方法。本文就淋球菌的分型方法作一简要介绍。     

杭州市淋病奈瑟菌质粒酶切图谱分析研究

目的 :了解杭州市淋病奈瑟菌质粒携带及质粒谱型分布情况。方法 :采用碱裂解法对门诊 2 0 0 0年 1月～ 2 0 0 1年 10月分离的 2 0 7株淋病奈瑟菌进行了质粒抽提及质粒谱分型研究 ,并对菌株的青霉素耐药现象和耐药性质粒的关系进行探讨。结果 :2 0 7株淋病奈瑟菌中 194株 (93 .7% )检见质粒带 ,其中含一条质粒带的 112株 (5 4.11% ) ,含两条质粒带的 12株 (5 .8% ) ,含三条带的 70株 (3 3 .82 % ) ,尚有 13株(6.2 8% )未检测到质粒。以 E.coli V5 17细菌质粒作分子量标准 ,测得这些分子量分别为 2 .6、4.5、和 2 4.5Md。质粒谱型以 2 .6 4.5 2 4.5 Md(3 3 .82 % )多见。结论 :杭州地区质粒酶切图谱的分析研究有助于淋病的治疗和防治 ,这将对该地区淋病奈瑟菌的分子流行病学调查和淋病监控提供依据     

淋病奈瑟菌的耐药质粒及其转移机制

质粒作为一种染色体外的遗传物质,可以编码很多重要的生物学性状。淋病奈瑟菌（淋球菌）质粒可以分为３种类型：耐药性质粒、隐蔽性质粒和接合性质粒。耐药性质粒包括耐青霉素质粒和耐四环素质粒。质粒在菌株间的转移主要是通过转化和接合两种方式进行。ＤＮＡ片段中的１０ｂｐ特异摄取序列与有效转化密切相关,而转座子在接合中起重要作用。     

淋病奈瑟氏菌及其分类学研究进展

<正>淋病奈瑟氏菌(简称淋球菌)及其感染是国际上重要的研究课题之一。自从十九世纪七十年代从淋病患者病灶脓细胞中分离到淋球菌至今已有百余年,其抗原结构和分群、分型的研究有了较大进展,外膜蛋白、菌毛蛋白及脂多糖等抗原的分析正在深入进行。自1976年发现青霉素耐药菌株之后,对于耐药菌株及质粒的研究有了新的突破,促进了对该病的防治工作。     

淋病奈瑟菌实验诊断方法学的评价

淋病是临床常见的性传播疾病。本文根据了淋病奈瑟菌（淋球菌）的实验室诊断分级、质控标准。并对诊断方法,尤其是核酸检测技术的敏感性与特异性进行了评估。     

淋病奈瑟菌耐药机制研究进展

淋病是由淋病奈瑟菌(淋球菌)感染引起的一种性传播疾病,其流行和蔓延已成为全球公共卫生事业巨大的负担.抗菌药物治疗是目前淋病防治的主要方式,但随着抗菌药物在临床上的广泛应用,淋球菌的耐药性问题日益严重.深入探究淋球菌的耐药机制,对完善其耐药监测体系和调整临床用药方案均有重要意义.本文在回顾近几年淋球菌耐药机制相关研究的基...     

淋病奈瑟菌孔蛋白疫苗研究进展

淋病奈瑟菌孔蛋白具有较强的免疫原性和相对缓慢的抗原变异性。近年来,淋病奈瑟菌孔蛋白结构、抗原性及其影响因素等方面的研究进展推动了该菌疫苗的研究。     

淋病奈瑟菌感染实验室检测技术的进展

细菌培养是诊断淋病奈瑟菌(NG)感染的"金标准",也是目前诊断淋病最可靠的方法.但淋病奈瑟菌在人体外抵抗力极弱,不易培养;仅做细菌形态学检查,诊断意义有限.随着淋病奈瑟菌耐药性不断增强,多重耐药菌出现并广泛传播.高敏感性、高特异性、操作简便的分子生物学检验技术,如单管多重聚合酶链反应(PCR)技术等,已开始用于淋病奈瑟...     

淋病奈瑟菌多重传递耐药主动外排系统的研究进展

淋病奈瑟菌多重传递耐药系统属于细菌的主动外排系统,与淋球菌多重耐药的发生有密切关系,本文就该系统的组成,功能,基因调控及与淋球菌多重耐药间关系等方面的研究现状作一概述,并讨论对该系统进一步研究的意义。     

淋病奈瑟菌感染的实验室诊断技术概述

淋病奈瑟菌是淋病的病原菌,淋病不及时诊断和治疗会引起严重的并发症,早期诊断和治疗是控制淋病传播的关键。试验诊断技术在淋病的诊断和治疗中具有十分重要的作用。目前,常用的试验诊断方法有涂片镜检、分离培养、免疫学方法、分子生物学检查和快速检查等。分泌物直接涂片染色镜检大多常用革兰染色,但是有其局限性,细菌培养是诊断淋病的金标准,也是目前诊断淋病最可靠的方法,但淋病奈瑟菌培养困难,仅做细菌学培养检查,诊断意义有限。随着新仪器的研发以及现代分子生物学理论和技术的发展,快速、准确、特异、敏感的分子生物学技术已经成为试验诊断的重要手段,具有广阔的应用前景,临床上还需要开发新的核酸扩增试验技术,以便更好地指导临床治疗。临床医生在实际诊疗过程中应该根据患者的实际情况正确选择检测方法,有时建议选择两种以上的检测方法以提高阳性检出率。本文就淋病奈瑟菌感染的试验诊断技术的研究进展加以概述。     

铜绿假单胞菌PA16株粘附性、菌毛与质粒关系的研究

为探讨PA的质粒与粘附性及质粒与菌毛的关系,围绕PA16株的耐药性与质粒的关系、质粒与菌毛及粘附性的关系作了一系列的研究,结果表明PA16对所测的7种抗生素全部耐药,其MIC＞400 mg/L;PA16仅含有一种27.3 kb(18 Mu)的质粒.转化后此质粒也使JM109获得了对四环素的耐药性.消除此质粒后,PA16对四环素的耐药性消失.粘附试验证明PA16质粒消除株对尿道上皮细胞的粘附能力较野生株显著性减小(P＜0.05),同时,透射电镜照片显示PA16野生株表面有致密、纤细刚直的菌毛,而PA16质粒消除株表面几乎无菌毛可见.     

白色念珠菌和热带念珠菌对人肺上皮细胞的粘附作用及其差异性比较

目的探讨白色念珠菌和热带念珠菌对人肺上皮细胞的粘附作用及其差异性.方法将白色念珠菌和热带念珠菌临床分离株在体外与人肺上皮细胞共同作用,经革兰染色后,在倒置显微镜下观察念珠菌对肺上皮细胞的粘附数.结果念珠菌粘附的肺上皮细胞与浓度和时间有依赖关系.菌液浓度在5×103CFU/ml至5×107CFU/ml范围内,念珠菌对肺上皮细胞的粘附作用随念珠菌浓度的增加而增强.白色念珠菌对肺上皮细胞的粘附数比热带念珠菌的粘附数要高.来自痰、尿标本的同一种念珠菌对人肺上皮细胞的粘附数无明显差异.结论念珠菌对人肺上皮细胞的粘附是一种特异性的粘附,临床标本来源的白色念珠菌粘附宿主细胞的能力比热带念珠菌强.     

淋球菌耐药性与耐药质粒的研究

为了解湛江地区淋球菌耐药现状及耐药质粒的分布,并初步探讨其相互关系,对１９９８￣１９９９年广东省湛江地区健康鉴定出的９８株淋球菌流行株,应用纸片扩散法测定细胞对１０种抗生素的敏感性,并采用碱裂解法进行质粒抽提,分析耐药质粒的分布情况,选取ＮＧ４、ＮＧ３１、ＮＧ４３、ＮＧ７０进行细菌的接合试验,以观察耐药质粒能否通过接合进行传递以及传递后受体菌耐药性的变化。结果显示６．１２％菌株对全部抗生素敏感,４８．９６％的菌株对３种及３种以上的抗生素耐药;共检出四种不同分子量的质闰,７．４ｋｂ和４．２ｋｂ质粒检出率较高,分别为５９．１６％和６７．３２％,质粒谱型１２种,以７．４ｋｇ＋４．２ｋｇ和３９．５ｋｇ＋７．４ｋｇ＋４．２ｋｇ为主,占３８．７６％。在细菌的接合传递试验中,ＮＧ４３可通过接合传递将其耐药性传递给淋球菌及大肠     

双歧杆菌质粒的检测及其对抗生素敏感性

本文应用ＬｅＢＬａｎｃ法提取６种２０株双歧杆菌菌株的质粒,发现共有４个种的６株菌株存在着１～３个质粒,多数质粒的分子量小于６．０ｋｂ。存在质粒的双歧杆菌包括分离自人的短双歧杆菌、青春双歧杆菌、两歧双岐杆菌和婴儿双歧杆菌。用固体培养基滤纸片抑菌圈法测定双歧杆菌对１５种常用抗生素的敏感性,结果表明,测试的２０株双歧杆菌菌株对所检测的１５种抗生素的敏感性无规律可循,而且质粒消除实验表明质粒的存在与所检测的抗生素抗性无相关性。     

大肠埃希菌耐药性监测及耐药质粒的研究

为了解医院内感染大肠埃希菌的耐药情况,探讨其耐药发生、流行及传播机制,对从临床分离的32株大肠埃希菌进行了药敏试验、质粒图谱分析以及质粒接合、转化试验,结果表明大肠埃希菌对氨苄青霉素的耐药率＞88%,对庆大霉素的耐药率＞75%,其中28株大肠埃希菌检出质粒,均含有一条分子量为5.66 Mu的质粒带,是医院内感染大肠埃希菌的流行质粒.质粒的接合、转化试验证实了质粒具有横向传播的特点,是细菌产生耐药的主要原因.     

EFFECTS OF SINUSOIDAL MAGNETIC FIELD ON ADHERENCE INHIBITION OF LEUKOCYTES

Response of leukocytes to exposure to an external magnetic field with frequency 50 Hz and sinusoidal waveform was investigated in vitro using the leukocyte adherence inhibition (LAI) assay developed as a measure of cell-mediated immunity. Leukocytes taken from healthy humans adhere, but their adherence decreases after 1 hr of exposure to the magnetic field with magnetic induction of 1 and 10 mT. The majority of leukocytes taken from cancer patients before any medical treatment do not adhere, and exposure to the magnetic field increases adherence. Correlation between the LAI assay results and the cell-mediated immunity suggests an effect of magnetic fields on leukocyte immune function in humans.     

氨基酸产生菌E_(65)中质粒的分离与鉴定

在棒杆菌与短杆菌中,用微量质粒分离方法筛选到一株含多种质粒的乙酰短杆菌(Brevibacterium actylicum)E_(65)菌株,该菌株具有产氨基酸特性。进一步大量制备其质粒DNA,并进行氧化绝密度梯度超离心纯化,以及电泳分析,电镜观察,并对质粒进行分离与鉴定,从而确定了每种质粒的分子量大小。     

Antigenic cross-reactivity between outer membrane proteins of Neisseria meningitidis and commensal Neisseria species

Two mouse sera against outer membrane proteins from a pathogenic Neisseria meningitidis strain and a commensal N. lactamica strain and two human sera from patients recovering from meningococcal meningitis were used to identify antigens common to pathogenic and commensal Neisseria species. Two major antigens of 55 kDa and 32 kDa, present in all N. meningitidis and N. lactamica strains tested, were demonstrable with all the sera used; the 55-kDa protein was iron-regulated. Demonstration of other common antigens was dependent on the serum used: a 65-kDa antigen was visualised with the human and the mouse anti-N. lactamica sera; a 37-kDa antigen identified as the meningococcal ferric binding protein (FbpA) was only detected with the mouse sera, and two antigens of 83 kDa and 15 kDa were only shown with the mouse anti-N. meningitidis serum. The results demonstrate the existence of several outer membrane antigens common to N. lactamica and N. meningitidis strains, in agreement with the hypothesis that natural immunity against meningitis is partially acquired through colonisation by commensal species, and open new perspectives for the design of vaccine formulations and the development of strategies for vaccination against meningitis.     

Carriage of Neisseria meningitidis and Neisseria lactamica in northern Greece

In response to an increase in the number of cases of invasive meningococcal disease (IMD) in northern regions of Greece, a survey was carried out to determine if there was an increase in carriage of Neisseria meningitidis, particularly in areas where there have been increases in immigrant populations from neighbouring countries. The second objective was to determine if there was an increase in the serogroup C:2a:P1.5,2 a phenotype associated with recent outbreaks or changes in antibiotic sensitivities. As carriage of Neisseria lactamica is associated with development of natural immunity to IMD, the third objective was to determine the carriage rate of N. lactamica in this population. Among 3167 individuals tested, meningococci were isolated from 334 (10.5%). Compared with our previous studies, the proportion of meningococcal carriers was significantly increased among children in secondary education (11.3%) (chi2=9.67, P<0.005) and military recruits (37.4%) (chi2=21.11, P<0.000). Only 5/334 (1.5%) isolates expressed the phenotype associated with the increase in IMD in Greece. N. lactamica was isolated from 146/3167 (4.6%) participants. It was isolated from 71/987 (7.2%) children attending primary or nursery schools; however, the highest proportion of carriers (11.3%) was found in the boarding school for young Albanian men. In the 21-59-year age range, the majority of N. lactamica isolates (22/25, 88%) were from women, probably due to closer or more prolonged contact with children in the primary school age range. Smoking was significantly associated with isolation of meningococci from men but not from women. Penicillin-insensitive strains (25/334, 7.5%) were identified in all four regions examined; the majority (14/25, 56%) were obtained from military personnel. We conclude that there was a higher proportion of carriers in the population of northern Greece; however, the increase in carriage rate was not associated with the influx of immigrants from neighbouring countries, and there was not a higher incidence of the C:2a:P1.5,2 strain responsible for increased disease activity in Greece in either the immigrant or local populations.