Detection of mutations associated with multidrug-resistant Mycobacterium tuberculosis clinical isolates

Antimicrobial resistance was studied in 100 Mycobacterium tuberculosis strains selected randomly from sputum cultures of newly diagnosed tuberculosis patients. Resistance of the isolates to rifampicin, isoniazid, and ethambutol was tested by both drug susceptibility testing (DST) and allele-specific PCR (AS-PCR). A total of 19 (19%) isolates were found resistant to at least one of the antituberculosis drugs investigated by PCR compared with 14 (14%) resistant isolates detected by DST. Eleven mutations were detected by AS-PCR in the rpoB gene (codons 516, 526, and 531), associated with rifampicin resistance, a marker of multidrug-resistant tuberculosis (MDR-TB), 14 mutations in the katG gene codon 315 that confers resistance to isoniazid, and nine mutations in the embB gene codon 306 that confers resistance to ethambutol. Mutations in the six multidrug-resistant isolates were confirmed by DNA sequencing. Results were compared with phenotypic DST data. Nineteen different mutation types to at least one of the drugs were found; six isolates (6%) were classified as MDR-TB, defined as resistance to at least rifampicin and isoniazid. The rates of concordance of the PCR with the phenotypic susceptibility test were 71.4, 54.5, and 44.4 for isoniazid, rifampicin, and ethambutol, respectively. These results highlight the importance of molecular epidemiology studies of tuberculosis in understudied regions with a tuberculosis burden to uncover the true prevalence of the MDR-TB.     

Prevalence of mutations at codon 463 of katG gene in MDR and XDR clinical isolates of Mycobacterium tuberculosis in Belarus and application of the method in rapid diagnosis

Isoniazid (INH) is a central component of drug regimens used worldwide to treat tuberculosis. In respect to high GC content of Mycobacterium tuberculosis, nonsynonymous mutations are dominant in this group. In this study a collection of 145 M. tuberculosis isolates was used to evaluate the conferring mutations in nucleotide 1388 of katG gene (KatG463) in resistance to isoniazid. A PCR-RFLP method was applied in comparison with DNA sequencing and anti-mycobacterial susceptibility testing. From all studied patients, 98 (67.6%) were men, 47 (32.4%) were women, 3% were <15 and 9% were >65 years old; male to female ratio was 1:2.4. PCR result of katG for a 620-bp amplicon was successful for all purified M. tuberculosis isolates and there was no positive M. tuberculosis culture with PCR negative results (100% specificity). Subsequent PCR RFLP of the katG identified mutation at KatG463 in 33.3%, 57.8% and 59.2% of our clinically susceptible, multidrug resistant TB (MDR) and extensively drug resistant (XDR) isolates, respectively. Strains of H37Rv and Academic had no any mutations in this codon. M. bovis was used as a positive control for mutation in KatG463. Automated DNA sequencing of the katG amplicon from randomly selected INH-susceptible and resistant isolates verified 100% sequence accuracy of the point mutations detected by PCR-RFLP. We concluded that codon 463 was a polymorphic site that is associated to INH resistance (a missense or "quiet" mutation). RFLP results of katG amplicons were identical to those of sequence method. Our PCR-RFLP method has a potential application for rapid diagnosis of M. tuberculosis with a high specificity.     

Molecular fingerprinting of isoniazid-resistant Mycobacterium tuberculosis isolates from chest diseases hospital in Kuwait

Touchdown double-repetitive-element-PCR (DRE-PCR) was carried out for typing 38 consecutive isoniazid-resistant Mycobacterium tuberculosis strains isolated at Chest Diseases Hospital, Kuwait, during 1998-2000. The polymorphism at codon 463 in the katG gene was also determined and correlated with genotypic relationships among the isolates. The isolates exhibited 21 distinct patterns in DRE-PCR. Nearly half of the isolates (18 of 38) exhibited unique patterns. Majority of isolates (16 of 20) yielding multiple DNA fragments in DRE-PCR were unique strains while most of the isolates (16 of 18) yielding a single DNA fragment in DRE-PCR clustered together. The prevalence of L463 in the katG gene was much higher in isolates from Middle Eastern (mostly Kuwaiti) patients than is reported for this ethnic group. The data indicate the possibility of some strains of South Asian/Southeast Asian origin spreading among local populations.     

Truncated structural variants of lipoarabinomannan in Mycobacterium leprae and an ethambutol-resistant strain of Mycobacterium tuberculosis

Current knowledge on the structure of lipoarabinomannan (LAM) has resulted primarily from detailed studies on a few selected laboratory strains of Mycobacterium tuberculosis, Mycobacterium bovis BCG, and Mycobacterium smegmatis. Our previous work was the first to report on the salient structural features of M. tuberculosis clinical isolates and demonstrated significant structural variations. A prime effort is to correlate a particular structural characteristic with observed differences in eliciting an immunobiological response, especially in the context of CD1-restricted presentation of LAM to T cells. T cell clones derived from the cutaneous lesions of leprosy patients have been shown to recognize specifically LAM from Mycobacterium leprae and not from M. tuberculosis Erdman or H37Rv. Herein we provide further fine structural data on LAM from M. leprae (LepLAM) and a tuberculosis clinical isolate, CSU20 (CSU20LAM), which was unexpectedly recognized by the supposedly LepLAM-specific CD1-restricted T cell clones. In comparison with the de facto laboratory LAM standard from M. tuberculosis H37Rv (RvLAM), LepLAM derived from in vivo grown M. leprae is apparently simpler in its arabinan architecture with a high degree of exposed, non-mannose-capped termini. On the other hand, CSU20, an ethambutol-resistant clinical isolate, makes a vastly heterogeneous population of LAM ranging from rather small and non-mannose-capped to full-length and fully capped variants. LepLAM and CSU20LAM contain a higher level of succinylation than RvLAM, which, in the context of truncated or less elaborated arabinan, may contribute to selective recognition by T cells. LAM from all species could be resolved into discrete forms by isoelectric focusing based apparently on their arabinan heterogeneity. In the light of our current and more recent findings, we reason that all immunobiological data should be cautiously interpreted and that the actual LAM variants that may be present in vivo during infection and pathogenesis need to be taken into consideration.     

Occurrence of RD9 region and 500 bp fragment among clinical isolates of Mycobacterium tuberculosis and Mycobacterium bovis

The present investigation dealt with the identification of Mycobacterium tuberculosis and M. bovis by RD9 region and 500 bp fragment PCR assays. Eight M. tuberculosis and 5 M. bovis characterized and identified from 40 human sputum and 41 bovine lung specimens and 20 M. tuberculosis and 9 M. bovis strains maintained at Mycobacteria Laboratory, Indian Veterinary Research Institute were included in this study. In this way, 28 M. tuberculosis and 14 M. bovis strains and, for comparison and control purpose, M. tuberculosis H37Rv, M. bovis BCG, M. canetti, M. smegmatis, M. phlei, M. chelonae, M. kansasii, M. xenopi and M. avium were subjected to RD9 and 500 bp amplification by PCR. All M. tuberculosis strains, M. tuberculosis H37 Rv and M. canetti yielded a product of 333 bp which showed presence of RD9 region in these strains, whereas all M. bovis yielded a product of 206 bp with RD9 PCR assay. There was no ampli-fication product found in M. bovis BCG, M. xenopi, M. smegmatis, M. phlei, M. chelonae, M. kansasii, and M. avium. PCR based on 500 bp fragment showed a product of 500 bp in all M. bovis strains and M. bovis BCG. There was no amplification product of 500 bp found in M. canetti, M. smegmatis, M. phlei, M. chelonae, M. avium, M. kansasii, M. xenopi and was absent in all M. tuberculosis strains. The PCR assay results correlated 100% with the culture and biochemical results of the isolates. Our study suggested that PCR based on RD9 and 500 bp may effectively identify two closely related species of M. tuberculosis and M. bovis.     

Biological properties of clinical isolates of Mycobacterium tuberculosis

The invasiveness of 2 grud sensitive and 8 holy-resistant M. tuberculosis clinical isolated was evaluated in experiments on BALB/c mice. Mycobacterial suspension was injected into the caudal vein of experimental animals. The results were evaluated by the degree of contamination of lungs and spleen of infected animals euthanized at different periods on time. The study revealed high variability in the degree of contamination of the organs of the animals infected with M. tuberculosis drug-resistant clinical isolates.     

结核分枝杆菌katG基因突变的研究

探讨编码过氧化氢-过氧化物酶的katG基因突变与结核分枝杆菌异烟肼(INH)耐药性的相关关系。根据结核分枝杆菌GenBank中的katG序列,自行设计特异性寡聚核苷酸引物,采用聚合酶链反应-单链构象多态性(PCR-SSCP)分析和直接测序法(DS)分析结核分枝杆菌中katG基因突变情况。以HR37Rv标准株为对照。所有23株敏感菌均未有SSCP结果异常;35株耐药菌中,有2株(5．7％)katG基因扩增阴性,且发生在高度耐药菌中。进一步分析发现,SSCP法突变检出23株(65．7％),测序法突变检出24株(68．6％),符合率为95．8％(23／24)。参照测序法对耐药菌突变序列的分析结果,PCR—SSCP敏感、特异,可快速检测结核分枝杆菌katG耐药基因突变,有利于耐药结核分枝杆菌耐药性的快速检测。     

Comparative genomic analysis of Mycobacterium tuberculosis clinical isolates

Background

Due to excessive antibiotic use, drug-resistant Mycobacterium tuberculosis has become a serious public health threat and a major obstacle to disease control in many countries. To better understand the evolution of drug-resistant M. tuberculosis strains, we performed whole genome sequencing for 7 M. tuberculosis clinical isolates with different antibiotic resistance profiles and conducted comparative genomic analysis of gene variations among them.

Results

We observed that all 7 M. tuberculosis clinical isolates with different levels of drug resistance harbored similar numbers of SNPs, ranging from 1409–1464. The numbers of insertion/deletions (Indels) identified in the 7 isolates were also similar, ranging from 56 to 101. A total of 39 types of mutations were identified in drug resistance-associated loci, including 14 previously reported ones and 25 newly identified ones. Sixteen of the identified large Indels spanned PE-PPE-PGRS genes, which represents a major source of antigenic variability. Aside from SNPs and Indels, a CRISPR locus with varied spacers was observed in all 7 clinical isolates, suggesting that they might play an important role in plasticity of the M. tuberculosis genome. The nucleotide diversity (Л value) and selection intensity (dN/dS value) of the whole genome sequences of the 7 isolates were similar. The dN/dS values were less than 1 for all 7 isolates (range from 0.608885 to 0.637365), supporting the notion that M. tuberculosis genomes undergo purifying selection. The Л values and dN/dS values were comparable between drug-susceptible and drug-resistant strains.

Conclusions

In this study, we show that clinical M. tuberculosis isolates exhibit distinct variations in terms of the distribution of SNP, Indels, CRISPR-cas locus, as well as the nucleotide diversity and selection intensity, but there are no generalizable differences between drug-susceptible and drug-resistant isolates on the genomic scale. Our study provides evidence strengthening the notion that the evolution of drug resistance among clinical M. tuberculosis isolates is clearly a complex and diversified process.

Electronic supplementary material

The online version of this article (doi: 10.1186/1471-2164-15-469) contains supplementary material, which is available to authorized users.     

Detection and characterization of mutations in genes related to isoniazid resistance in Mycobacterium tuberculosis clinical isolates from Iran

Molecular Biology Reports - The global rise in drug-resistant Mycobacterium tuberculosis (M.tb), and especially the significant prevalence of isoniazid (INH)-resistance constitute a significant...     

IS6110-mediated deletion polymorphism in the direct repeat region of clinical isolates of Mycobacterium tuberculosis

This study investigates the phenomenon of IS6110-mediated deletion polymorphism in the direct repeat (DR) region of the genome of Mycobacterium tuberculosis. Clinical isolates and their putative predecessors were compared using a combination of DR region restriction fragment length polymorphism, IS6110 DNA fingerprinting, spoligotyping, and DNA sequencing, which allowed the mapping of chromosome structure and deletion junctions. The data suggest that adjacently situated IS6110 elements mediate genome deletion. However, in contrast to previous reports, deletions appear to be mediated by inversely oriented IS6110 elements. This suggests that these events may occur via mechanisms other than RecA-mediated homologous recombination. The results underscore the important role of IS6110-associated deletion hypervariability in driving M. tuberculosis genome evolution.     

Genetic diversity of Iranian clinical isolates of Mycobacterium tuberculosis

In the current study we aimed to execute a rather less complicated molecular tying method, i.e. the random amplification of polymorphic DNA (RAPD) analysis to find the heterogeneity of Iranian strains of Mycobacterium tuberculosis. The isolates comprised a total of 96 strains of M. tuberculosis collected from clinical specimens of patients in Isfahan and Tehran. The isolates were assigned to the species M. tuberculosis by the key conventional and molecular methods. They were then subjected to RAPD analysis by four arbitrary primers, namely, the primers 27F, 1525R, MS- GF and INS-2. They were then evaluated for the number and intensity of the band patterns. The RAPD profiles of the Iranian isolates showed a degree of heterogeneity which varied based on the primer used. However, analysis of the isolates by primer INS-2 revealed the highest degree of diversity yielding 31 distinguishable RAPD types. RAPD analysis provides a rapid and easy means of identifying heterogeneity among the M. tuberculosis isolates. This typing system might be considered a valuable alternative molecular typing for countries with limited resources provided that the reproducibility and reliability of the method is carefully assured.     

Molecular characterization of rpoB gene mutations in rifampicine-resistant Mycobacterium tuberculosis isolates from tuberculosis patients in Belarus

The aim of this study was to investigate the frequency, location and type of rpoB mutations in Mycobacterium tuberculosis isolated from patients in Belarus. Tuberculosis cases are increasing every year in Belarus. Moreover, resistance to anti-tuberculosis drugs, especially to rifampicine, has increased. In this study, 44 rifampicine-resistance M. tuberculosis clinical isolates (including multidrug-resistant isolates) were subjected to DNA sequencing analysis of the hypervariable region (hot-spot) of the rpoB gene originating from different geographical regions in Belarus. Sixteen different types of mutations were identified. The most common point mutations were in codons 510 (47.7%), 526 (45.5%), 523 (40.86%) and 531 (29.5%). Eleven isolates (27.7%) carried one mutation and 23 (52%), 7 (16%), 3 (7%) of isolates carried 2, 3 and 4 mutations, respectively. A characteristic, prominent finding of this study was high frequency of multiple mutations in different codons of the rpoB gene (27.7%) and also the detection of unusual types of mutations in the 510 codon, comprising CAG mutations (deletion or changing, to CTG, CAC or CAT). In our study, the change TTG in codon 531 was found in 92% of isolates and the change TGC in 8% of isolates. A TAC change in codon 526 was not found, but the GAC change was found in all isolates. Isolates of M. tuberculosis isolated in Belarus were characterized by the wide spectrum of the important mutations and might belong to the epidemic widespread clones.     

Analysis of intracellular expressed proteins of Mycobacterium tuberculosis clinical isolates

Background

Tuberculosis (TB) is the most threatening infectious disease globally. Although progress has been made to reduce global incidence of TB, emergence of multidrug resistant (MDR) TB threatens to undermine these advances. To combat the disease, novel intervention strategies effective against drug resistant and sensitive subpopulations of M. tuberculosis are urgently required as adducts in the present treatment regimen. Using THP-1 cells we have analyzed and compared the global protein expression profile of broth-cultured and intraphagosomally grown drug resistant and sensitive M.tuberculosis clinical isolates.

Results

On comparing the two dimensional (2-DE) gels, many proteins were found to be upregulated/expressed during intracellular state which were identified by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). Four proteins (adenosylhomocysteinase, aspartate carbomyltransferase, putatitive thiosulfate sulfurtransferase and universal stress protein) were present in both intracellular MDR and sensitive isolates and three of these belonged to intermediary metabolism and respiration category. Two proteins (alanine dehydrogenase and adenosine kinase) of intracellular MDR isolate and two (glucose-6-phosphate isomerase and ATP synthase epsilon chain) of intracellular sensitive isolate belonged to intermediary metabolism and respiration category. One protein (Peroxidase/Catalase) of intracellular MDR and three (HSPX, 14 kDa antigen and 10 kDa chaperonin) of sensitive isolate belonged to virulence, detoxification and adaptation category. ESAT-6 of intracellular MDR belonged to cell wall and cell processes category. Two proteins (Antigen 85-C and Antigen 85-A) of intracellular sensitive isolate were involved in lipid metabolism while probable peptidyl-prolyl cis-trans isomerase A was involved in information pathways. Four (Rv0635, Rv1827, Rv0036c and Rv2032) of intracellular MDR and two proteins (Rv2896c and Rv2558c) of sensitive isolate were hypothetical proteins which were functionally characterized using bioinformatic tools. Bioinformatic findings revealed that the proteins encoded by Rv0036, Rv2032c, Rv0635, Rv1827 and Rv2896c genes are involved in cellular metabolism and help in intracellular survival.

Conclusions

Mass spectrometry and bioinformatic analysis of both MDR and sensitive isolates of M. tuberculosis during intraphagosomal growth showed that majority of commonly upregulated/expressed proteins belonged to the cellular metabolism and respiration category. Inhibitors of the metabolic enzymes/intermediate can therefore serve as suitable drug targets against drug-resistant and sensitive subpopulations of M. tuberculosis.     

PCR-SSCP检测结核分枝杆菌利福平耐药相关基因rpoB突变

目的 建立聚合酶链反应-单链构象多态性(PCR-SSCP)技术快速检测结核分枝杆菌利福平(RFP)耐药相关基因rpoB突变.方法 设计结核分枝杆菌RFP耐药相关rpoB基因PCR引物,建立PCR-SSCP技术检测临床菌株rpoB基因的突变导致的运动变位,同时采用PCR直接测序(PCR-DS)技术检测rpoB基因突变,并对上述方法检测结果进行分析和比较.结果 84株临床菌株均含有rpoB基因;PCR-SSCP和PCR-DS检测结果显示,56株RFP敏感菌株中rpoB基因分别有3株和2株检测出突变,检测特异性分别为94.6％ (53/56)和96.4％(54/56);28株RFP耐药菌株中rpoB基因分别有27株和28株发生突变,检测灵敏度分别为96.4％和100％.结论 本研究建立的PCR-SSCP技术能快速、简便、特异、敏感地检测结核分枝杆菌利福平耐药基因rpoB突变,具有临床应用前景.     

深圳地区结核分枝杆菌耐利福平株rpoB基因突变分布

目的:调查深圳地区结核分枝杆菌耐利福平(RFP)株rpoB基因突变的分布情况,建立结核分枝杆菌耐药基因快速检测的方法.方法:对55株结核分枝杆菌临床分离株的rpoB基因280个碱基(包括其核心区75个碱基)应用PCR-直接测序法(PCR-DS)测定序列,其中耐利福平株51株,敏感株4株.结果:4株敏感株无突变,92.2%(47/51)耐利福平临床分离株存在rpoB基因突变.基因突变导致531位氨基酸突变率为41.2%(21/51);导致526位氨基酸突变率为29.4%(15/51);导致516位氨基酸突变率为13.7%(7/51).联合突变发生率为2.0%(1/51).未检测到发生缺失或插入碱基突变的菌株.结论:深圳地区结核分枝杆菌耐利福平株发生rpoB基因突变最常见的是531位丝氨酸、526位组氨酸和516位天冬氨酸的基因突变,三者突变率之和为84.3%(43/51).PCR-DS方法可快速测定结核分枝杆菌RFP耐药基因突变.     

Characteristics of clinical isolates of Mycobacterium tuberculosis using molecular biological methods

A total of 230 clinically drug-resistant and 3 drug-sensitive isolates of M. tuberculosis obtained from patients in Tula and Tula region in 1998-2001 were studied. The RFLP-IS6110 genotyping showed that 52 (30.2%) of isolates had unique patterns, and 120 (69.8%) of them were grouped to form 16 clusters. 95 (55.2%) and 53 (30.8%) of isolates were attributed to groups A1 and W (Beijing), respectively. Double mycobacterium cultures were detected in 4.1% of isolates. 2 to 4 clinical isolates were obtained from each of 55 patients during 1.5 years. A replacement of mycobacterium isolates was registered in the course of treatment in 12 (21.8%) patients. No replacement of clinical isolates occurred in 43 (78.2%) patients during the whole follow-up period. Repeatedly obtained isolates acquired the determinants of drug-resistance in 5 (11.6%) patients. Changes in the quantity of IS6110 elements were registered only in 1.05% of isolates during a 3-year follow-up.     

Molecular characterization of Mycobacterium tuberculosis isolates in a region of Brazil with a high incidence of tuberculosis

One hundred and seventy Mycobacterium tuberculosis clinical isolates were characterized by spoligotyping to evaluate the biodiversity of tubercle bacilli in a region of Brazil with a high incidence of tuberculosis (Pelotas and Rio Grande cities - Rio Grande do Sul State). The spoligotyping results were compared to the World Spoligotyping Database (Institut Pasteur de Guadeloupe), which contains data from >14,000 worldwide isolates of M. tuberculosis. The isolates clustered by spoligotyping were further characterized by IS6110-RFLP to confirm the clonal relationship. Sixty-six different spoligotypes were identified, grouping 125 of the isolates (74%). Approximately half of the isolates belonged to seven of the most frequently occurring spoligotypes in the database. Three shared types (with two or more isolates) not previously identified were given the type numbers 826, 827 and 863. An additional 45 spoligotypes were identified that did not match any existing database pattern. RFLP characterization reduced the number of isolates in most of the clusters, thereby showing a higher differentiation capacity than spoligotyping. These results highlight the importance of molecular epidemiology studies of tuberculosis in insufficiently studied regions with a high TB burden, in order to uncover the true extent of genetic diversity of the pathogen.     

Glycolipids of recent clinical isolates of Mycobacterium tuberculosis: chemical characterization and immunoreactivity

Five distinct glycolipids were readily detected in isolates of Mycobacterium tuberculosis. Spectroscopic methods and chemical degradation techniques allowed the structural identification of four of these glycolipids. The specific phenolic glycolipid antigen previously characterized from the Canetti strain was found in all the strains examined, with identical structural features (triglycosyl phenol phthiocerol dimycocerosate). The other three glycolipids identified were acylated trehaloses: penta-acyl trehalose (containing phthienoyl substituents), tetra-acyl trehalose 2'-sulphate (with C40-C50 hydroxyphthioceranoyl substituents) and diacyl trehalose 2'-sulphate (with C16 and C18 substituents). The two latter glycolipids as well as the phenolic glycolipid immunoreacted with whole-cell antiserum, indicating their surface location. The occurrence of these glycolipid antigens in recent clinical isolates suggests their possible utilization in the serodiagnosis of tuberculosis and the rapid identification of M. tuberculosis with specific antisera.     

Variation in mannose-capped terminal arabinan motifs of lipoarabinomannans from clinical isolates of Mycobacterium tuberculosis and Mycobacterium avium complex

The unique terminal arabinan motifs of mycobacterial lipoarabinomannan (LAM), which are mannose-capped to different extents, probably constitute the single most important structural entity engaged in receptor binding and subsequent immunopathogenesis. We have developed a concerted approach of endoarabinanase digestion coupled with chromatography and mass spectrometry analysis to rapidly identify and quantitatively map the complement of such terminal units among the clinical isolates of different virulence and drug resistance profiles. In comparison with LAM from laboratory strains of Mycobacterium tuberculosis, an ethambutol (Emb) resistant clinical isolate was shown to have a significantly higher proportion of nonmannose capped arabinan termini. More drastically, the mannose capping was completely inhibited when an Emb-susceptible strain was grown in the presence of subminimal inhibitory concentration of Emb. Both cases resulted in an increase of arabinose to mannose ratio in the overall glycosyl composition of LAM. Emb, therefore, not only could affect the complete elaboration of the arabinan as found previously for LAM from Mycobacterium smegmatis resistant mutant but also could inhibit the extent of mannose capping and hence its associated biological functions in M. tuberculosis. Unexpectedly, an intrinsically Emb-resistant Mycobacterium avium isolate of smooth transparent colony morphology was found to have most of its arabinan termini capped with a single mannose residue instead of the more common dimannoside as established for LAM from M. tuberculosis. This is the first report on the LAM structure from M. avium complex, an increasingly important opportunistic infectious agent afflicting AIDS patients.     

定量蛋白质组学分析链霉素耐药和敏感结核分枝杆菌临床分离株

[目的]发现结核分枝杆菌(Mycobacterium tuberculosis)链霉素耐药相关的潜在菌体蛋白.[方法]以结核分枝杆菌临床分离链霉素敏感株01105和结核分枝杆菌H37Rv为对照,采用iTRAQ技术和生物信息学鉴定并相对定量结核分枝杆菌临床分离链霉素耐药株01108菌体蛋白,并通过WEGO功能注释聚类分析01108菌株差异表达蛋白的细胞组分、分子功能和生物进程.[结果]01108菌株分别与01105菌株和H37Rv菌株比较差异表达蛋白为194个和146个,01108菌株与01105菌株和H37Rv比较均差异表达蛋白121个(共同差异表达蛋白).差异表达蛋白理论相对分子量和等电点分布广泛,其生物进程主要参与中间代谢、呼吸作用和脂质代谢,分子功能主要为催化活性功能和结合功能.共同差异表达蛋白:7个核糖体蛋白(Rv2785c,Rv0056,Rv0641,Rv0652,Rv0701,Rv1630和Rv2442c)在01108菌株中表达下调;7个蛋白在01108菌株中显著差异表达(上调大于1.20倍或下调小于0.55倍),分别为巯基过氧化物酶(Rv1932)、酰基载体蛋白脱氢酶(Rv0824c)、30S核糖体蛋白S15 (Rv2785c)、丙酮酸脱氢酶E2部分(Rv2215)、双组份转录调控蛋白(Rv3133c)以及假定未知蛋白(Rv2466c和Rv2626c).[结论]iTRAQ发现了链霉素耐药结核分枝杆菌相对于链霉素敏感结核分枝杆菌和H37Rv共同差异表达蛋白,为进一步探讨结核分枝杆菌链霉素耐药机制奠定了基础.