PCR-RFLP和PCR指纹法在新生隐球菌基因分型中的应用与比较

目的 探讨针对结构基因g6341的PCR－RFLP方法在新生隐球菌基因分型中的应用价值, 并与PCR指纹分型法进行比较。方法 以野生型噬菌体M13中针对小卫星DNA的核心序列为单引物，对受试的新生隐球菌进行PCR指纹分型。选择结构基因g6341进行PCR－RFLP分析，在序列保守区设计通用引物，筛选合适的限制性内切酶进行RFLP分析，并与PCR指纹法进行比较。g6341基因扩增片段测序，进行系统发育分析，研究各主要基因型间的亲缘关系。结果 多位点基因序列分析表明，结构基因g6341可作为RFLP分析的合适靶点。对76株新生隐球菌的基因分型结果显示，针对g6341的PCR-RFLP方法与PCR指纹法结果一致。分析g6341基因部分序列得出，8种主要基因型菌株相互间的同源性在84％ ～ 97％之间，同一主要基因型菌株的同源性在99％ ～ 100％之间。分子发育树中，VNⅠ－VNⅣ基因型、VGⅠ－VGⅣ基因型分别聚在一类。结论 针对结构基因g6341的PCR-RFLP方法可作为新生隐球菌分子分型的有效工具，对g6341基因的序列分析可揭示不同菌株间的遗传进化关系。     

Molecular epidemiology and antifungal susceptibility of Serbian Cryptococcus neoformans isolates

Molecular typing and antifungal susceptibility testing of 34 clinical Serbian Cryptococcus neoformans isolates from 25 patients was retrospectively performed. Amplified fragment length polymorphism (AFLP) fingerprinting was used for genotyping, whereas a novel real‐time PCR was used to determine the mating‐ and serotype. The antifungals amphotericin B, 5‐fluorocytosine, fluconazole, voriconazole, itraconazole and posaconazole were used to determine the antifungal susceptibility profiles. The majority of isolates belonged to genotype AFLP1/VNI (n = 20; 58.8%), followed by AFLP2/VNIV (n = 10; 29.4%), AFLP3/VNIII (n = 3; 8.8%) and AFLP1B/VNII (n = 1; 2.9%). All AFLP1/VNI isolates were mating–serotype αA, the sole AFLP1B/VNII isolate was found to be a A, whereas AFLP2/VNIV harboured serotype D isolates with either the a (n = 2; 5.9%) or α (n = 8; 23.5%) mating‐type allele. The isolates (n = 3; 8.8%) that were found to be genotype AFLP3/VNIII had the hybrid mating‐ and serotype combination a A‐αD. In vitro antifungal susceptibility testing showed that all isolates were susceptible to amphotericin B, voriconazole and posaconazole. Low resistance level was observed for fluconazole (n = 1; 2.9%) and 5‐fluorocytosine. (n = 2; 5.8%). A large percentage of isolates was found to be susceptible dose dependent to itraconazole (n = 16; 47.1%). AFLP1/VNI was the most common genotype among clinical C. neoformans isolates from immunocompromised patients in Serbia. C. neoformans from HIV‐negative patients were significantly less susceptible to 5‐fluorocytosine (P < 0.01). Correlation between genotypes and antifungal susceptibility was not observed.     

Fluorescence-labeled methylation-sensitive amplified fragment length polymorphism (FL-MS-AFLP) analysis for quantitative determination of DNA methylation and demethylation status

The PCR-based DNA fingerprinting method called the methylation-sensitiveamplified fragment length polymorphism (MS-AFLP) analysis isused for genome-wide scanning of methylation status. In thisstudy, we developed a method of fluorescence-labeled MS-AFLP(FL-MS-AFLP) analysis by applying a fluorescence-labeled primerand fluorescence-detecting electrophoresis apparatus to theexisting method of MS-AFLP analysis. The FL-MS-AFLP analysisenables quantitative evaluation of more than 350 random CpGloci per run. It was shown to allow evaluation of the differencesin methylation level of blood DNA of gastric cancer patientsand evaluation of hypermethylation and hypomethylation in DNAfrom gastric cancer tissue in comparison with adjacent non-canceroustissue.     

福建省畲族人群结核分支杆菌IS6110DNA指纹图谱特征分析

目的分析福建省畲族人群和汉族人群结核病患者分支杆菌DNA指纹特征,探讨畲族人群结核病的分子流行病学特征。方法采用基于IS6110的PCR分型方法,对我省10个畲族乡镇调查点分离的50例畲族人群结核菌株和50例汉族人群结核菌株进行检测,用Gel-Pro analyzer4.0软件和NTSYSpc2.10e软件对DNA指纹图谱进行聚类分析。结果100株结核分支杆菌共分为4个主要类型,其中Ⅰ型(北京基因型)59株占59%,Ⅱ型38株占38%,Ⅲ型2株占2%,IV型为1株占1%。汉族病例菌株指纹为Ⅰ、Ⅱ型,以I型为主,占80%,畲族为Ⅰ、Ⅱ、Ⅲ、Ⅳ型,以II型为主,占56%;经χ2分析,两族病例菌株指纹的型别分布差异有显著统计学意义(P<0.01)。Ⅱ型菌株耐药率(47.4%,18/38)与Ⅰ型菌株耐药率(20.3%,12/59)差异也有显著统计学意义(P<0.05)。结论畲、汉两族主要基因型不同,汉族人群以北京基因型(Ⅰ型)流行为主,而畲族人群则以非北京基因型(Ⅱ型)为主,该型菌耐药率明显高于Ⅰ型,提示与畲族人群结核病高疫情相关,有待于进一步研究。     

A primer for ZooMS applications in archaeology

Collagen peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, also known as zooarchaeology by mass spectrometry (ZooMS), is a rapidly growing analytical technique in the fields of archaeology, ecology, and cultural heritage. Minimally destructive and cost effective, ZooMS enables rapid taxonomic identification of large bone assemblages, cultural heritage objects, and other organic materials of animal origin. As its importance grows as both a research and a conservation tool, it is critical to ensure that its expanding body of users understands its fundamental principles, strengths, and limitations. Here, we outline the basic functionality of ZooMS and provide guidance on interpreting collagen spectra from archaeological bones. We further examine the growing potential of applying ZooMS to nonmammalian assemblages, discuss available options for minimally and nondestructive analyses, and explore the potential for peptide mass fingerprinting to be expanded to noncollagenous proteins. We describe the current limitations of the method regarding accessibility, and we propose solutions for the future. Finally, we review the explosive growth of ZooMS over the past decade and highlight the remarkably diverse applications for which the technique is suited.     

金黄色葡萄球菌稳定L型的鉴定及其应用

目的 鉴定从一例恶性淋巴瘤患者骨髓中三次分离出的稳定L型。方法 对此菌株进行了生物学性状观察,免疫细胞化学染色及DNA酶切图谱分析,并以该菌株DNA制备探针,用原位杂交法检测了宫颈癌和子宫内膜癌的组织切片。结果 证实该菌株是金黄色葡萄球菌L型,此探针能检出肿瘤组织中的金葡菌L型DNA。结论 从该恶性淋巴瘤患者骨髓中分离的系金葡菌L型,L型可能与肿瘤有关。     

基于ISSR标记的麻花艽遗传多样性分析

目的探讨秦艽基原植物之一麻花艽Gentiana straminea的遗传多样性,并构建DNA指纹谱。方法在其自然分布区广泛取样,共涉及西藏、青海、甘肃及四川等地28个居群83份样本,应用ISSR分子标记技术,POPGEN软件分析遗传信息参数,NTSYS软件构建亲缘关系UPGMA聚类图。结果从100条引物中筛出7条多态性好、条带清晰的引物用于ISSR分析。共检测到95个条带,其中多态性条带88个,多态性条带百分率(PPL)为92.63%;麻花艽居群间的期望杂合度(H_e)为0.288 2,多样性信息指数(I_m)为0.437 1,种群间基因分化系数(G_(st))为0.678 3,基因流(N_m)为0.237 1,遗传距离为0.074 3~0.490 0。UPGMA树将麻花艽居群主要分为2大支。结论麻花艽种群遗传多样性水平较高,居群间遗传多样性水平高于居群内;其遗传变异主要存在于居群间;遗传特性与地理分布具有一定相关性。该工作可为麻花艽品种鉴定、物种就地保护、探讨环境等因素对于遗传分化的影响及药材道地性研究提供基础资料。     

人工牛黄薄层指纹图谱多元图像分析及化学计量学研究

建立了人工牛黄薄层指纹图谱,对其图像进行数字化和化学计量学研究。首先采用以环己烷-乙酸乙酯-乙酸-甲醇(2∶7∶1∶2)为展开剂,10%硫酸乙醇溶液为显色剂,105℃加热至斑点清晰,并在366 nm下采集数码图像。然后将该图像转换成为灰度图像,得到指纹图谱的灰度曲线图多元数据,并采用主成分分析法对多元数据进行分析。结果表明薄层指纹图谱可表征不同生产企业生产的人工牛黄,并且分析得到图谱上表征来源的特征区域。该方法简便,快速,适合用于不同来源的人工牛黄质量差异的评价。     

黄芪及其民间习用品DNA指纹图谱和有效成分含量的比较

 目的比较2000年版药典收载黄芪品种及其民间习用品的DNA指纹图谱和有效成分黄芪甲苷、总黄酮及总多糖的含量,对黄芪质量标准进行多维研究。方法RAPD法确定DNA指纹图谱,HPLC-ELS测定黄芪甲苷的含量,比色法测定总黄酮的含量,硫酸-苯酚法测定黄芪总多糖的含量。结果DNA指纹图谱分析表明膜荚黄芪、蒙古黄芪和梭果黄芪有着较近的遗传关系,而另外3种黄芪,即苦黄芪、黑毛多枝黄芪和直立黄芪有非常近的亲缘关系。有效成分含量的测定结果证实,黑毛多枝黄芪、直立黄芪中黄芪甲苷的含量高于膜荚黄芪和蒙古黄芪;总黄酮的含量以梭果黄芪最高;总多糖的含量以蒙古黄芪最高。结论对民间使用的黄芪品种进行多维质量研究,为开发黄芪的药用资源提供理论依据。     

附子生药的高效液相色谱指纹图谱研究

目的:研究附子生药的高效液相色谱指纹图谱,为科学评价药材质量提供可靠方法。方法:利用 HPLC-DAD 方法,梯度洗脱,测定了四川不同产地的14批附子生药。色谱条件为:Hypersil BDS C_(18)分析柱(150 mm×4.6 mm,5 μm);柱温30℃;流动相40 mmol·L~(-1)醋酸铵(氨水调pH 10.0)-乙腈梯度洗脱;流速1.0 mL·min~(-1);检测波长为240 nm。结果:14批附子生药得到的色谱指纹图谱有25个共有峰,通过与对照品的保留时间、紫外光谱及 LC/MS 所得相对分子质量信息比较,7,18,20,22号峰分别鉴定为苯甲酰新乌头原碱、新乌头碱、乌头碱和次乌头碱。结论:附子生药的指纹图谱特征性及专属性强,可结合含量测定用于全面控制附子生药的质量,并为进一步确保采用规范化炮制工艺制得质量稳定均一的炮制品提供依据。