Mycobacterium tuberculosis

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结核分枝杆菌Rv2660c蛋白结构分析及抗原表位预测

目的 分析结核分枝杆菌Rv2660c蛋白的结构并预测其抗原表位,为研发针对结核潜伏性感染的治疗性疫苗和药物提供新的靶点。方法 用BLAST软件分析Rv2660c蛋白与人类蛋白的同源性,然后运用生物信息学方法预测其二级结构、跨膜结构、信号肽序列及T细胞和B细胞抗原表位。结果 BLAST结果显示,Rv2660c蛋白与人类蛋白同源性不高,同源性最高的人类蛋白是MAD 6蛋白,同源性仅为16%。Rv2660c蛋白无跨膜区,为胞外蛋白,不含信号肽序列;该蛋白含丰富的B细胞和T细胞抗原表位,19-35、48-54、28-44和58-73位氨基酸残基可能存在优势线性B细胞表位;56-64位和65-74位氨基酸可能存在优势辅助性T细胞表位,66-74、41-49、63-71位氨基酸可能存在优势细胞毒性T细胞表位。结论 Rv2660c蛋白含丰富抗原表位,具有较强的体液免疫和细胞免疫原性,可望作为潜伏性感染结核的治疗性疫苗和药物的作用靶点。     

Spoligotyping and Mycobacterium tuberculosis

We evaluated the clinical usefulness of spoligotyping, a polymerase chain reaction-based method for simultaneous detection and typing of Mycobacterium tuberculosis strains, with acid-fast bacilli-positive slides from clinical specimens or mycobacterial cultures. Overall sensitivity and specificity were 97% and 95% for the detection of M. tuberculosis and 98% and 96% when used with clinical specimens. Laboratory turnaround time of spoligotyping was less than that for culture identification by a median of 20 days. In comparison with IS6110-based restriction fragment length polymorphism typing, spoligotyping overestimated the number of isolates with identical DNA fingerprints by approximately 50%, but showed a 100% negative predictive value. Spoligotyping resulted in the modification of ongoing antimycobacterial treatment in 40 cases and appropriate therapy in the absence of cultures in 11 cases. The rapidity of this method in detection and typing could make it useful in the management of tuberculosis in a clinical setting.     

结核分枝杆菌的间隔寡核苷酸分型法(Spoligotyping)

结核分枝杆菌是引起结核病的主要病原体。近年来，针对结核分枝杆菌的分子生物学研究方法日臻成熟，Spoligotyping分型就是其中的一种。它是指针对多种不同的间隔序列(位于结核分枝杆菌染色体上DR序列之间)，设计各自特异的寡核苷酸探针，并固定在尼龙膜上，引物标记后的扩增产物与膜上的探针进行反向杂交。由于不同菌株的间隔序列不同。因此导致杂交的探针数量和种类也不同而产生多态性。这种方法在流行病学研究中可以用来调查结核病暴发流行。追踪和寻觅传染源，确定结核病及耐药结核病的传播机制，鉴定实验室交叉污染或院内感染和阐述结核分枝杆菌菌株分布及优势株的情况。     

Mycobacterium tuberculosis Beijing genotype

Molecular epidemiologic studies of strains of Mycobacterium tuberculosis are currently conducted worldwide. The genetically distinct Beijing family of strains has been associated with large outbreaks of tuberculosis, increased virulence, and multidrug resistance. However, in this first population-based search for Beijing strains in the Danish DNA fingerprint database, analysis of 97% of all culture-positive tuberculosis patients in 1992 to 2001 showed that 2.5% of 3,844 patients, 1.0% of Danish-born patients, and 3.6% of immigrants (from 85 countries) had Beijing strains. No Beijing strains were found among 201 strains from Danish-born patients sampled in the 1960s, and no evidence of an increase in Beijing strains was found over time. The true prevalence of Beijing strains worldwide is unknown because only a fraction of global strains have been analyzed.     

Mycobacterium tuberculosis complex detection in human remains: tuberculosis spread since the 17th century in Rio de Janeiro, Brazil

Paleogenetic analysis for tuberculosis (TB) was conducted on bone and sediment samples dating from the 17th to 19th centuries from the archeological site of Nossa Senhora do Carmo Church in Rio de Janeiro, Brazil. Forty samples were analyzed, corresponding to 32 individuals from 28 burials, 22 of primary type and 6 of secondary type. The samples were collected following strict paleogenetic investigation guidelines and submitted to ancient DNA (aDNA) extraction. In order to detect TB infection, aDNA hybridizations with the molecular targets of Mycobacterium tuberculosis complex (MTC) IS6110 and IS1081 were applied. Additionally, the ancestry of individuals was assessed by human mitochondrial DNA (mtDNA) analysis of hypervariable segment I (HVS-I) sequence polymorphisms. The results of aDNA hybridizations demonstrated varying levels of MTC intensity in 17/32 individuals (53.1%), using the IS6110 target. The IS1081 MTC target showed lower sensitivity, confirming TB positivity in 10/32 (31.2%) individuals. The mtDNA analysis allowed the recovery of HVS-I sequences in 23/32 individuals (71.8%). The majority of these individuals (21/23, 91.3%) were of European ancestry, especially in primary burials. Haplogroups U, J, V, T, K, N, H and R, were identified with haplogroup U being the most frequent at 6/23 (26.1%). African and Amerindian mtDNA haplogroups were observed in two individuals in secondary burials. In spite of the ecclesiastic and aristocratic bias of the population of the study, human ancestry analysis revealed the prominent contribution of Europeans in the introduction or spread of TB in the New World.     

Global distribution of Mycobacterium tuberculosis spoligotypes

We present a short summary of recent observations on the global distribution of the major clades of the Mycobacterium tuberculosis complex, the causative agent of tuberculosis. This global distribution was defined by data-mining of an international spoligotyping database, SpolDB3. This database contains 11708 patterns from as many clinical isolates originating from more than 90 countries. The 11708 spoligotypes were clustered into 813 shared types. A total of 1300 orphan patterns (clinical isolates showing a unique spoligotype) were also detected.     

Multidrug-Resistant Mycobacterium tuberculosis, Southwestern Colombia

Using spoligotyping, we identified 13 genotypes and 17 orphan types among 160 Mycobacterium tuberculosis isolates from patients in Valle del Cauca, Colombia. The Beijing genotype represented 15.6% of the isolates and was correlated with multidrug-resistant tuberculosis, female sex of the patients, and residence in Buenaventura and may represent a new public health threat.     

血清结核杆菌Hsp10对胸腰椎体结核杆菌感染的辅助诊断效果

目的探讨血清结核杆菌Hsp10对胸腰椎体结核杆菌感染的诊断效果。方法选取2017年7月-2018年7月住院治疗的疑似胸腰椎体结核患者98例,其中确诊为胸腰椎体结核杆菌感染患者52例为感染组,未感染46例为未感染组,并选取同时健康体检者45例为对照组。所有患者均进行结核菌素的实验检查,结核感染T细胞检测,以及Hsp10含量的检测,比较三种检测方法的有效性和一致性。结果感染组血清结核杆菌Hsp10含量为(125.24±21.57) pg/ml,非感染组为(89.41±20.33) pg/ml,对照组为(86.20±18.87) pg/ml,感染组显著高于非感染组与对照组(P<0.05)。以血清结核杆菌Hsp10含量对胸腰椎体结核杆菌感染作ROC曲线,曲线下面积为0.88,临界值为109.52 pg/ml。血清结核杆菌Hsp10含量检测方法的敏感性80.00%,特异性73.33%;结核菌素的实验敏感性61.54%,特异性31.61%;血清结核杆菌Hsp10含量的检测方法与结核菌素的实验的检测方法具有较高的一致性。结论血清结核杆菌Hsp10含量的检测方法可以作为胸腰椎体结核杆菌感染的有效辅助诊断方法。     

结核分枝杆菌的复苏因子

1998年Mukamolova等在细菌因子一文中首先提出了复苏因子(resuscitation promoting factor,Rpf)的新概念,并证实复苏因子是由有活性的微球菌分泌的一种蛋白质,它在皮摩尔级浓度就能有效地促进休眠的非生长同源菌的复苏和生长。同时也证实微球菌复苏因子类似基因广泛地存在     

Mycobacterium tuberculosis Beijing genotype, the Netherlands

To determine whether the Beijing genotype of Mycobacterium tuberculosis is emerging in the Netherlands, we collected data on 6,829 patients during 1993 to 2000. Six percent had the Beijing genotype. This genotype was associated with diagnosis in recent years, young age, nationality, and multidrug resistance.