杭州地区结核分枝杆菌氧氟沙星耐药株的MIRU-VNTR基因分型研究

目的：探讨MIRU-VNTR技术在杭州地区结核分枝杆菌氧氟沙星耐药株基因分型中的应用。方法收集杭州市2010年4月-2012年6月各结核病定点医院分离培养的临床菌株,进行药物敏感性检测。分别采用RD105缺失基因检测法和MIRU-VNTR技术对氧氟沙星耐药株进行菌株鉴定和基因分型。结果筛选出的52株氧氟沙星耐药株中,43株（82.69%）为北京家族菌株。经12个MIRU-VNTR位点组合分析,52株氧氟沙星耐药株呈52种MIRU-VNTR基因型,总Hunter-Gaston指数（ HGI）为0.999。除MIRU40和ETR-F外,其他10个MIRU-VNTR位点对北京家族菌株和非北京家族菌株均显示较高或中等程度的分辨率。结论筛选到的10个MIRU-VNTR位点具有较高分辨率,适用于杭州地区结核分枝杆菌氧氟沙星耐药株分型。     

不同串联重复序列位点组合用于中国结核分枝杆菌基因分型的能力比较分析

目的 初步评价不同串联重复序列(VNTR)位点在中国8省市结核分枝杆菌基因分型中的应用,寻找适合中国地区结核分枝杆菌基因分型的位点组合.方法 从中国8个省(市、自治区)2800余株结核分枝杆菌临床分离菌株中以简单数字表法随机抽取140株,采用多位点数目可变串联重复序列分析方法(MLVA)对27个数目可变VNTR位点进行基因多态性检测,采用BioNumerics数据库软件进行单位点和不同位点组合的分辨率(Hunter-Gaston指数,HGI)分析,并比较分析其对140株菌的基因分型鉴定能力.同时采用间隔区寡核苷酸分型(Spoligotyping)将140株菌分为北京家族和非北京家族,评价上述不同VNTR位点组合在北京家族和非北京家族中的分型能力.结果 140株菌主要可分为2个基因群,即北京家族112株,占80%;非北京家族28株,占20%.Spoligotyping分型对140株结核分枝杆菌的HGI为0.4589.MLVA分析结果显示不同位点在不同菌株群存在明显的多态性,不同位点的HGI具有较大差异(0～0.809),对全部菌株、北京家族菌株、非北京家族菌株的HGI达到0.5以上的VNTR位点数分别为8、7和14个.27个VNTR位点进行不同的位点组合:优化筛选的8位点组合、国际推荐的12个、15个和24个位点组合.4个组合的HGl分别为0.9991、0.9882、0.9980和0.9986;在北京家族菌株中,上述组合的HGI依次为0.9987、0.9318、0.9969和0.9975;在非北京家族菌株中分别为1、0.9894、1和1.结论不同的VNTR位点和不同VNTR位点组合在中国8省市结核分枝杆菌中的HGI均存在明显差异;本研究优化的8个位点组合MLVA分型方法在中国结核分枝杆菌流行病学研究可能具有良好的应用前景.     

中国嗜肺军团菌分离株脉冲场凝胶电泳分型分析以及数据库的建立

目的 对分离的262株嗜肺军团菌进行脉冲场凝胶电泳(PFGE)分析,初步建立中国嗜肺军团菌的PFGE分型数据库.方法 采用PFGE技术,对2004-2009年中国11个省(市)分离的嗜肺军团菌用AscⅠ酶切,BioNumerics软件分析PFGE图谱,并建立分子分型数据库.结果 262株嗜肺军团菌的PFGE图谱共分为108种不同的PFGE带型,相似性系数在16%～100%之间,通过聚类分析,可以分为差异明显的不同簇.不同省份、年份和血清型的菌株之间有交叉带型.结论 中国环境分离的嗜肺军团菌菌株基因组变异较大,同时也具有克隆化特征,且可能有多个克隆系存在.

Abstract：

Objective To analyze the molecular types of Legionella (L.) pneumophila strains isolated in China,and to develop the PulseNet-China Database of L.pneumophila.Methods Pulsed field gel electrophoresis (PFGE) was used to analyze 262 L.pneumophila strains collected from 11 provinces between 2004 and 2009 in China.Different kinds of genomic DNA in different L.pneumophila strains were isolated and separated after digesting with Asc Ⅰ.BioNumerics software was used to analysis the PFGE fingerprints.Results L.pneumophila strains isolated in China were quite different regarding their PFGE patterns.There were 108 PFGE types among the 262 strains tested in this study.The similarity value of these strains was in the range of 16%-100% and the same types were discovered in different provinces and years.Conclusion L.pneumophila strains isolated in China were with high genetic variations.There might be different clones existed in China.The development of PulseNet China Database was thus of great significance in monitoring the L.pneumophila strains in the future.     

2008年和2010年肠道病毒7l型广州分离株全基因组序列分析

目的 研究2008年和2010年广州地区手足口病患者中肠道病毒71型(EV71)病毒全基因组序列的基因型与变异特点.方法 参照GenBank上EV71深圳株SHZH03(AY465356)基因组设计分段扩增引物,进行RT-PCR分段扩增EV71病毒基因组,PCR产物直接进行序列测定,用Clustal W/X、DNASTAR、MEGA4.1等软件分析基因组序列.结果 克隆9株广州株EV71,病毒全基因组全长序列均为7405 bp,提交到GenBank上的序列号为HQ456305、HQ456306、HQ456307、HQ456308、HQ456309、HQ456310、HQ456311、HQ456312、HQ456313.将9株广州株EV71与EV71的A、B3、B4、B5、C1、C2、C3、C4型及阜阳株全基因组核苷酸序列进行Clustal W比较,发现与C4a型阜阳株等同源性为98%～99%,与C4b同源性为91%～93%,与C1～C3同源性为82%～83%,与B3～B5同源性为81%～83%,与A型同源性为80%.将9株广州分离株EV71的VP1基因与EV71病毒A、B、C型进行Clustal W比较,同样是与C4a为98%～99%,与C4b同源性为92%～94%,与C1～C3的同源性为88%～89%,与B1～B5型同源性为83%～84%,与A型同源性为81%～82%.将9株广州株与EV71的A、B、C型VP1基因氨基酸序列进行Clustal W比对,发现VP1基因22位点的谷氨酰胺转变为组氨酸(Q→H),聚合蛋白中213位点(S→T)和1764位点(V→(Ⅰ)也发生了氨基酸的点突变,P的213位点属于VP2基因,1764位点属于3D基因.结论 2008年和2010年分离的9株广州株EV71属于C4a型,与阜阳株同源性为98%～99%,VP1基因22位点发生了点突变,聚合蛋白中213位点和1764位点也发生了氨基酸的点突变.

Abstract：

Objective To study the genomic genotypes and variation of human enterovirus 71(EV71)infected infants in Guangzhou city,in 2008 and 2010.Methods Primers were designed on the basis of the genomic sequence of EV71 SHZH03 strain(AY465356)in the GenBank,and EV71genome amplified by RT-PCR.PCR-products were directly sequenced and the genomic nucleotide sequences were analyzed with the programs of Clustal W/X,DNASTAR and MEGA 4.1.Results 9strains of EV71 genome appeared to be 7405 bp in length.The genomic sequences of EV71Guangzhou strains were compared with those of EV71 in GenBank,which revealed that the homology with EV71 genotype C4a Fuyang strains ranged between 98%-99%.Homology with genotype C4b were 92%-94%,with genotypes C1,C2,C3 as 82%-83%,with genotypes B3,B4,B5 as 81%-83%and the homology with genotype A was 80%.When compared the VP1 genes of EV71 Guangzhou strains with genotypes A,B,C virus,we revealed that the highest homology was also with genotype C4a.When compared the VP1 amino acid sequences of EV71 Guangzhou strains with genotype A,B,C virus by Clustal W program,the results revealed that the amino acid residue Q at position 22 in VP1gene was transformed to H,while 213(S→T)and 1764(V→(Ⅰ))mutations in polyprotein were discovered.Conclusion Data from the sequences and phylogenetics analysis on those Guangzhou strains in 2008 and 2010 revealed that those isolates belong to genotype C4a,with the homology with Fuyang strains as 98%-99%.Mutation of amino acid residue H at position 22 in VP1 gene was discovered and the neutralizing antibody of EV71 might have been conversed by this residue.213(S→T)and 1764(V→Ⅰ)mutations in polyprotein were also discovered.     

15位点重复单元-可变数目串联重复序列技术在河南地区结核分枝杆菌的基因分辨率的对比分析研究

目的 比较15位点分枝杆菌散在重复单元-可变数目串联重复序列(MIRU-VNTR)对河南省结核分枝杆菌的分辨力与其他地区的区别。方法 使用Spoligotyping和MIRU-VNTR对菌株进行分型,分析北京家族基因型在性别、年龄和地区间的分布情况。将15个位点对本省菌株的分辨率与其他地区结果相比较。结果 本省东部地区患者感染北京家族结核的比例高于其他地区,尤其高于西部地区。本省55岁以上的人群更易感染北京型菌株。7个位点(Mtub04、MIRU10、MIRU39、MIRU31、Mtub21、MIRU26和Qub26)对河南菌株的分辨能力优于其他地区。15位点MIRU-VNTR结合Spoligotyping的分辨力高于我国其他大部分地区,但略低于上海和黑龙江。结论 北京基因型在本省的分布存在地区和年龄的差异。15个位点MIRU-VNTR的分辨力在本省和其他地区间存在明显不同,因此需针对本省菌株指定合适的分型方案。     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

四川省结核分枝杆菌VNTR分型研究

目的评价不同串联重复序列(VNTR)位点在四川省结核分枝杆菌中的基因多态性,以及不同VNTR位点组合在四川省结核分枝杆菌基因分型中的应用。方法采用多位点数目可变串联重复序列分析技术(ML-VA)对102株四川省结核分枝杆菌菌株的15个VNTR位点进行分析,基因多态性分析采用Hunter-Gaston指数,聚类分析采用BioNumerics软件。结果 15个VNTR位点的基因多态性存在较大的差异,位点Mtub21(HGI 0.772)和MIRU26(HGI 0.764)的多态性较高,ETR-C(HGI 0.168)和MIRU23(HGI 0.077)的多态性较差。ETR-B和ETR-C两个位点在对四川省北京基因型结核分枝杆菌进行分型时则不具有多态性。对不同的VNTR位点组合进行比较,随着VNTR位点的增加,VNTR分型方法的分辨能力也有所提高。10个VNTR位点组合的分辨指数与15位点组合的分辨指数相差不大。同一VNTR位点在不同地区北京基因型菌株中的分辨力也存在较大的差异。结论不同VNTR位点在四川省结核分枝杆菌中具有不同的分辨力,并且同一VNTR位点在不同地区的北京家族菌株中的分辨力也不同。10个VNTR位点组合的基因分型方案可用于四川省结核分枝杆菌基因分型的一线方法。本研究的数据结果对挑选适合中国结核分枝杆菌基因分型的VNTR位点组合法具有重要的作用。     

Molecular typing and drug susceptibility of Mycobacterium tuberculosis isolates from Chongqing Municipality,China

China’s tuberculosis (TB) burden is second only to that of India worldwide. In Chongqing, the largest municipality in southwestern China, although the prevalence of both TB and drug-resistant TB is higher than in other municipalities, the molecular characteristics and drug susceptibility phenotypes are poorly known. In this study, 297 Mycobacterium tuberculosis isolates from Chongqing were genotyped with spacer oligonucleotide typing (spoligotyping) and 28-locus MIRU-VNTR (24-locus MIRU-VNTR scheme and 4 other loci). Spoligotyping results were compared with drug-resistant profiles. Patients who showed clustering by both spoligotyping and 28-locus MIRU-VNTR were interviewed to investigate their detailed contact history. Our data demonstrated that the Beijing genotype was the most prevalent genotype, and ST1 was the most predominant lineage in Chongqing. The Beijing genotype was significantly associated with ethambutol resistance and multidrug-resistant phenotypes. A combination of the 10 most polymorphic loci permitted to achieve higher discriminatory power than 24-VNTR. In addition, a presumed transmission pathway was observed in a cluster of patients with the same MIRU-VNTR profile. The 10-VNTR locus set is suitable for genotyping of Mycobacterium tuberculosis in Chongqing.     

河南省结核菌分离株26位点MIRU-VNTR和Spoligotyping分子分型及耐药分析

目的 探讨河南省结核杆菌的遗传多样性。方法 使用26位点（经典24位点和其他2位点）的分支杆菌散在重复单元中数目可变串联重复序列（mycobacterium interspersed repetitive unit-variable number tandem repeat,MIRU-VNTR）和间隔区寡核苷酸分型（spoligotyping）对来自2015年期间河南省不同地区的668株结核杆菌分离株进行分型分析。对结核菌spoligotype类型和耐药表型的相关性进行分析。结果 Spoligotyping分析表明668株结核杆菌被分到10个不同的基因簇中。北京家族基因型是河南地区结核杆菌中的优势菌株。北京家族基因型菌株对四种一线药全耐药以及耐多药菌株比例明显高于非北京型菌株。668株结核杆菌通过26位点VNTR被分为567个不同的基因型。26个位点中15个位点具有高度或适中的分辨能力。10个分辨能力最强位点的组合分辨力能与26位点相当。结论 北京家族是河南省最流行的结核杆菌基因型。10位点VNTR和spoligotyping相结合可有效地用于河南省结核杆菌进化遗传学研究。     

Genotypes and genetic characters of Mycobacterium tuberculosis from Myanmar using three typing methods

Knowledge on basic characteristics of Mycobacterium tuberculosis (MTB) is helpful to understand the disease epidemiology and support the prediction of clinical outcome of the disease. The aim of this study was to detect the genotypes and genotypic characters of clinical Mycobacterium tuberculosis (MTB) isolates from new and retreatment rifampicin-resistant patients using three different genotyping methods. Mycobacterial interspersed repetitive units-variable number tandem repeat (MIRU-VNTR) typing was used to determine the diversity of 222 clinical isolates. Spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) typing were also used to investigate the genetic characters of 105 MTB strains. Among the 15 genotypes detected by MIRU-VNTR, Beijing strains were the most prevalent of all strains (54.8%); new cases (40.5%) and retreatment cases (69.4%), followed by EAI strain. Spoligotyping categorized the strains into 11 lineages and 13 orphans whereas 96 different IS6110 patterns were identified using RFLP method. The mode number of IS6110 was 18 and 20. Higher band numbers were found in Beijing genotype (p < 0.001). Clustering rates by spoligotyping, MIRU-VNTR and IS6110-RFLP typing were 0.714, 0.004 and 0.085, respectively. Discriminatory powers of spoligotyping, MIRU-VNTR typing and IS6110-RFLP typing were 0.637, 1.000 and 0.997, respectively. Dominant Beijing genotype in both new and retreatment cases denoting that prevailing tuberculosis in Myanmar changed from EAI to Beijing lineage.     

三种不同的DNA分型技术在158株结核杆菌研究中的应用

目的评价IS6110限制性片段长度多态性(RFLP)、间隔区寡核苷酸分型(Spoligotyping)及分枝杆菌散在重复单位(MIRU)三种分型方法在结核病流行病学研究中的应用。方法对158株结核分枝杆菌临床分离株应用IS6110RFLP、Spoligotyping及MIRU三种分型方法进行鉴定。结果应用三种分型方法产生的类型数分别为118、20和105个。IS6110RFLP的分辨率大于Spoligotyping,MIRU的分辨能力与IS6110RFLP接近。在MIRU的12个区中,重复区4、10、26、40具有较高的多态性。广东地区与其他地区成簇率和北京基因型所占比例差异有统计学意义(P<0.05),广东地区成簇率和北京基因型所占比例均显著低于其他地区。结论应用IS6110RFLP、Spoligotyping及MIRU三种分型方法进行结核病流行病学研究具有重要意义且非常有效,可以发现中国不同地区菌株的不同特点。     

Genotyping of the Mycobacterium tuberculosis complex using MIRUs: association with VNTR and spoligotyping for molecular epidemiology and evolutionary genetics.

The recent introduction of molecular methods has gained increased acceptance as a powerful tool for epidemiology and phylogeny of tuberculosis (TB). In this investigation, the efficiency of molecular typing using mycobacterial interspersed repetitive units (MIRUs) was assessed on a set of 116 Mycobacterium tuberculosis complex clinical isolates from 11 different geographic origins. The results obtained were compared with spoligotyping and variable number of tandem DNA repeats (VNTRs) typing data. Eighty-nine different MIRU profiles were obtained on the sample studied. Spoligotyping- or VNTR-defined clusters were split into subclusters by MIRU typing. Conversely, almost all of the clinical isolates clustered by MIRUs were shown to belong to spoligotyping-based defined clusters. The calculation of the discriminative power by the Hunter-Gaston index (HGI) for VNTR, spoligotyping and MIRU typing gave the values of, respectively, 0.959, 0.965 and 0.988, showing the high discriminative power of the MIRUs. The allelic diversity of the sample was calculated for each of the MIRU-VNTR loci; five MIRU loci (MIRU nos. 10, 23, 26, 31 and 40) were "highly discriminant", four (MIRU nos. 4, 16, 24 and 39) were "moderately discriminant", and three (MIRU nos. 2, 20 and 27) were "poorly discriminant". Among the three complementary VNTRs (exact tandem repeats ETR-A, ETR-B and ETR-C), ETR-A was the most discriminant locus. A combined numerical analysis of spoligotyping, VNTR and MIRU typing results partly corroborated a recently hypothesized evolutionary scenario for the M. tuberculosis complex. M. canettii would be the first branch to have diverged from a common M. tuberculosis complex ancestor. The East-African Indian (EAI) clade could be the first family to have diverged thereafter. A third branching separated a M. africanum-M. bovis clade, followed by a node separating Beijing versus non-Beijing M. tuberculosis. The Beijing clade was distinct from the Central Asian 1 (CAS1) family. Among non-Beijing strains, branches such as the Latin-American and Mediterranean (LAM), X and Haarlem clades diverged later. In conclusion, the results obtained show the congruence between clades defined by spoligotyping, and MIRU-VNTR, and underline the potential of these methods for M. tuberculosis phylogeny reconstruction. We also conclude that MIRU typing is a very promising method that may be used in a "two PCR-based" genotyping strategy, in conjunction to conventional epidemiological investigations.     

我国西部贵州地区结核分枝杆菌分子流行病学初步研究

目的 分析结核分枝杆菌临床分离株的基因型特征,估计结核分枝杆菌近期在人群中传播的情况。方法 在肺结核报告发病率高的4个县级结核病门诊收集临床分离结核菌株的相关信息,应用RD105缺失基因和MIRU-VNTR基因分型技术分析结核分枝杆菌DNA多态性。结果 273株结核菌株中49.1%的菌株属于北京基因型,15 MIRU-VNTR位点组合进行分析,273株结核菌株共被分为262种不同的基因型,其中独特型251株,占91.9%,其余22株（8.1%）菌株属于11个不同的基因型,菌株成簇率为8.1%。结论 15位点组合用于本次分子流行病学研究,能准确反映贵州地区结核分枝杆菌分子流行病学特征,贵州省4个县结核分枝杆菌菌株呈现较高的多态性,其中8.1%的患者是由于近期本地区传播造成。     

上海市2000-2002年91株结核分枝杆菌分子流行病学分析

目的探讨上海地区结核病分子流行病学特点。方法对从上海市疾病预防控制中心菌株库中随机抽取的2000—2002年各50株耐药和敏感菌株进行间隔区寡核苷酸分型（Spoligotyping）和分枝杆菌散在分布重复单位（MIRU）基因型分型，并结合流行病学资料进行分析。结果抽样菌株中，具有特异Spoligotyping指纹图谱的北京基因型菌株在上海地区分布达89％（81／91）。未接种过卡介苗（BCG）的患者中北京基因型菌株占88．5％（54／61），接种过BCG的患者中北京基因型菌株占90％（27／30），差异无统计学意义。北京基因型菌株耐药率为45．7％（37181），低于非北京基因型菌株的耐药率60．0％（6／10），差异无统计学意义。MIRU成簇菌株占所有菌株的62．6％（57／91）。结论北京基因型菌株在上海地区有广泛分布，北京基因型菌株与BCG接种和耐药无关，结核病患者中有部分是由于近期传播而引起的。