结核分支杆菌五种耐药基因检测的临床应用及评价

目的　检测结核分支杆菌rpoBkatG、rpsL、pncA和embB耐药基因 ,评价其临床应用价值。方法　采用聚合酶链反应 单链构象多态性 (PCR SSCP)分析和药敏试验 (比例法 ) ,了解 10 9例肺结核患者结核分支杆菌耐药情况 ,并分析、比较临床治疗效果。结果　 1/ 2以上的肺结核患者至少耐两种抗结核药物 ,对RFP、INH、SM、PZA和EB总耐药率分别为 80 7%、71 5 %、78 8%、5 7 7%和48 6%。rpoB、katG、rpsL、pncA和embB基因突变率分别为 76%、68%、71%、5 1%和 3 0 %。结核分支杆菌耐药基因突变率与耐药水平联系密切 ,多数结核分支杆菌耐药基因突变易发生在高耐药株 ,也有少数基因突变发生在低耐药株。根据药敏试验和耐药基因检测结果 ,6个月耐多药结核治愈率分别达到 5 4 8%和 62 8% ,治疗效果满意 ,两种方法差异无显著性 (P >0 0 5 )。结论　耐药基因检测指导治疗是一种新探索 ,PCR SSCP方法敏感、特异 ,可以快速检测结核分支杆菌rpoB、katG、rpsL、pncA和embB耐药基因突变 ,可能会成为临床指导用药的好方法     

结核分支村菌耐药分子机制及快速检测的研究

目的：研究结核分支杆菌异烟肼、利福平耐药的分子机制，探索快速检测结核分支杆菌异烟肼、利福平耐药性的分子生物学方法。方法：应用聚合酶反应－单链构象多态性（PCR-SSCP）检测结核分支杆菌异烟肼、利福平耐药株与katG基因、rpoB基因突变。结果：46株结核分支杆菌临床分离株均未发现katG基因序列的缺失，30株异烟肼耐药株中，17株检测到katG基因突变，耐药株中katG基因的突变率为57％；87株结核分支杆菌利福平耐药临床分离株的PCR－SSCP结果显示，所有39株利福平敏感菌无突变检出，48株利福平耐药菌中，36株高度利福平耐药菌和7株低度利福平耐药菌检测量到rpoB基因突变；利福平耐药株中rpoB基因的突变检出率为89．6％。结论：证实katG和rpoB基因突变分别是结核分支杆菌异烟肼和利福平耐的主要分子机制。应用聚合酶链反应－单链构象多态性（PCR－SSCP）可快速检测结核分支杆菌异烟肼、利福平耐药性。     

耐多药肺结核耐药基因突变与临床疗效探讨

目的 了解耐多药肺结核耐药基因的突变与临床疗效的关系，为耐多药肺结核的治疗提供参考依据。方法 108例病人痰标本用PCR-SSCP方法检测了五种耐药基因和传统的药敏试验，并与临床疗效进行比较分析。结果 耐多药肺结核耐药基因检测率分别是耐异烟肼的katG基因突变率为70．4％，耐利福平的rpoB基因突变率72．2％，耐链霉素的rpsL基因突变率71．9％，耐吡嗪酰胺的pncA基因突变率53．4％，耐乙胺丁醇的embB基因突变率31．7％，其中高浓度耐药菌的基因突变率远高于低浓度的突变率。根据药敏试验及耐药基因检测结果指导治疗，应用以KAOP为基础的化疗方案，配合患者过去未曾用过的1-2种抗结核药物，经过平均1．4年的治疗，108例耐多药病人74．1％的病人痰菌阴转，且67．5％的病人痰结核杆菌培养阴转，83．3％的病人病灶吸收好转，65．3％的空洞闭合，取得了临床上较为满意的疗效。结论 对耐多药肺结核进行耐药基因检测是一项重要工作，对指导治疗及预后判断有一定的参考价值。但尚需进行更多的观察。     

应用PCR-SSCP技术检测痰中结核分枝杆菌katG、rpoB、embB基因突变的研究

目的 应用PCR-SSCP技术检测痰样本中结核分枝杆菌katG、rpoB、embB基因突变,探索其临床应用价值.方法 以结核分枝杆菌标准株H37Rv为对照,应用套式PCR扩增目的基因,并使用SSCP技术直接检测100例耐药患者和10例敏感患者痰样本中结核分枝杆菌katG、rpoB、embB基因突变并进行基因测序,将SSCP结果及测序结果与细菌培养药敏结果进行比较分析.结果 PCR-SSCP直接检测痰样本中的结核分枝杆菌katG基因突变的敏感性和特异性分别是55.9%和70.0%,rpoB为76.0%和90.0%,embB为46.4%和60.0%.结论 PCR-SSCP操作快速、简单,敏感性和特异性较高,可用来直接检测临床痰样本中结核分枝杆菌katG、rpoB、embB基因突变.     

聚合酶链反应—单链构象多态性技术检测耐多药结核分支杆菌rpoB、KatG、rpsL突变的研究

应用PCR-SSCP技术快速检测耐INH,RFP,SM结核分支杆菌分离株rpoB、KatG、rpsL基因突变,评价其在检测结核分支杆菌耐药性方面的价值。方法 32侏耐INH、RFP、SM结核分支杆菌临床分离株及25侏结核分支杆菌敏感分离株用PCR-SSCP方法分别检测,rpoB、KatG、rpsL基因突变。结果 32株耐多药结核分支杆菌分离株中,rpoB、KatG、rpsL PCR扩增产物PCR-SSCP分别有28株（87.5%)rpoB基因,19株（59.3%)KatG基因和23株（71.9%)rpsL基因电泳条带与结核分支杆菌标准株H37Rv电泳条带相比有明显差异,而25株结核分支杆菌敏感株的PCR-SSCP条带与结核分支杆菌H37Rv相似,特异性为100%。结论 PCR-SSCP方法敏感、特异,可快速检测结核分支杆菌rpoB、KatG、rpsL耐药基因突变,有利于耐多药结核分支杆菌耐药性的快速检测。     

煤工尘肺结核耐药菌的基因分析

目的 了解煤工尘肺结核患者所染结核杆菌对异烟肼、利福平、乙胺丁醇及链霉素耐药情况和基因突变情况，试图寻找有效的预防和诊疗方法。方法 从96份煤工尘肺结核患者痰标本中分离出64株耐异烟肼、利福平、链霉素及乙胺丁醇的结核杆菌，并用聚合酶链反应——单链构象多态性分析法(PCR—SSCP)扩增出katG、rpoB及rpsL片段，再将这些片段的8％非变性聚丙烯酰胺凝胶电泳图与标准株的电泳图进行对照分析。结果 常规药敏试验检测出各种耐药株共64株，经PCR—SSCP法分析，42株rpsL。异常，47株rpoB异常，42株katG异常。结论 大部分煤工尘肺结核患者的结核杆菌耐药分离株有基因突变，其突变率低于常规药敏试验结果。     

应用PCR-SSCP技术检测痰中结核分枝杆菌katG、rpoB、embB基因突变的研究

目的应用PCR-SSCP技术检测痰样本中结核分枝杆菌katG、rpoB、embB基因突变,探索其临床应用价值。方法以结核分枝杆菌标准株H₃₇R_V为对照,应用套式PCR扩增目的基因,并使用SSCP技术直接检测100例耐药患者和10例敏感患者痰样本中结核分枝杆菌katG、rpoB、embB基因突变并进行基因测序,将SSCP结果及测序结果与细菌培养药敏结果进行比较分析。结果PCR-SSCP直接检测痰样本中的结核分枝杆菌katG基因突变的敏感性和特异性分别是55.9%和70.0%,rpoB为76.0%和90.0%,embB为46.4%和60.0%。结论PCR-SSCP操作快速、简单,敏感性和特异性较高,可用来直接检测临床痰样本中结核分枝杆菌katG、rpoB、embB基因突变。     

应用基因芯片分析结核分枝杆菌常见耐药基因型的研究

目的应用基因芯片快速检测结核分枝杆菌耐药基因型，建立一种新的分子药敏试验方法。方法以传统药敏试验和PCR－直接测序方法为对照，应用基因芯片快速检测157株结核分枝杆菌临床分离株异烟肼（INH）、利福平（RFP）、链霉素（SM）和乙胺丁醇（EMB）耐药基因（katG、rpoB、rpaL、rrs和embB）的带荧光素标记的PCR产物。结果PCR-直接测序和基因芯片检测36株结核分枝杆菌药物敏感株的5种耐药基因均为野生型。121株结核分枝杆菌耐药分离株中，56株耐INH分离株，katG基因突变率为62．5％，其中katG缺失率为7．5％，315位密码子突变率为55．4％，279位密码子突变率为1．8％；104株耐RFP株，rpoB基因突变率为94．2％，最常见的突变位点为531位和526位密码子（突变率分别为60．6％、15．4％），双位点突变率为5．8％，还发现511、513、515、516、517、518和533位密码子突变；62株耐SM分离株，rpsL和ITS总突变率为88．7％（两者分别为82．3％、6．5％），rpsL突变位于43位和88位密码子（突变率分别为77．4％、4．8％），rrs突变位于513位和516位碱基（突变分别为4．8％、1．6％）；57株为耐EMB株，embB基因突变率为61．4％，均为306位密码子突变，最常见的突变为ATG→GTG或剐rA（突变率分别为35．1％、15．8％），还发现306位密码子ATG→ATC、ATT和CTG突变。通过基因芯片检出的突变与基因测序结果一致。结论应用基因芯片可分析大多数结核分枝杆菌耐药基因型，弥补传统药敏试验方法的不足，指导临床治疗。     

聚合酶链反应-单链构象多态性技术检测耐多药结核分支杆菌rpoB、KatG、rpsL突变的研究

目的　应用PCRSSCP技术快速检测耐INH,RFP,SM结核分支杆菌分离株KatG、rpoB、rpsL基因突变,评价其在检测结核分支杆菌耐药性方面的价值。方法 32株耐INH、RFP、SM结核分支杆菌临床分离株及25株结核分支杆菌敏感分离株用PCRSSCP方法分别检测,rpoB、KatG、rpsL基因突变。结果 32株耐多药结核分支杆菌分离株中,rpoB、KatG、rpsL PCR扩增产物PCR-SSCP分别有28株(87.5%)rpoB基因,19株(59.3%)KatG基因和23株(71.9%)rpsL基因电泳条带与结核分支杆菌标准株H₃₇Rv电泳条带相比有明显差异,而25株结核分支杆菌敏感株的PCR-SSCP条带与结核分支杆菌H₃₇Rv相似,特异性为100%。结论 PCR-SSCP方法敏感、特异,可快速检测结核分支杆菌rpoB、KatG、rpsL耐药基因突变,有利于耐多药结核分支杆菌耐药性的快速检测。     

耐多药结核分枝杆菌基因突变分析

目的对临床分离的耐多药结核分枝杆菌株进行基因突变分析。方法对耐多药结核分枝杆菌临床分离菌株进行耐药基因的PCR检测,利用基因序列测定方法分析耐药基因突变情况。结果从耐多药结核病（MDR-TB）患者临床分离菌株中快速检测到rpoB、katG、rpsL、embB基因及其突变。耐多药菌株、全耐及单耐利福平分离菌株均检测rpoB基因点突变,突变位点主要为第516、526和531常见密码子,1例MDR-TB出现第479位和第531位密码子同时突变。耐多药菌、全耐菌及单耐异烟肼的菌株均检测有katG基因点突变,突变位点均为第2066位碱基C突变为Go全耐菌和对乙胺丁醇（EMB）耐药的耐多药菌株均检测有embB基因点突变,突变位点均为第306位密码子ATG突变为ACG。全耐菌和对链霉素（SM）耐药的MDR-TB菌株均检测有rpsL基因点突变,突变密码子为CCT突变为CTT,其中从1株对SM敏感的MDR-TB中也检测到突变。全敏感株、标准株及利福平（RIF）、异烟肼（INH）或EMB敏感的耐药株均无rpoB、katG或embB基因突变。结论PCR及基因序列测定可快速检测耐多药结核基因,结核分枝杆菌耐多药性与多个基因突变相关。     

Lingual tuberculosis revealing disseminated tuberculosis

INTRODUCTION: Tuberculous lesions of the oral cavity are uncommon. Most of cases are secondary to pulmonary disease and the primary form is rare. EXEGESIS: We report the case of a 64 year-old man, smoker, presenting a chronic ulcer of the tongue, with anorexia and important weight loss. The biopsy of this ulcer showed granulomatous inflammation and Langhans type giant cells, without necrosis. Ziehl-Nielsen stain was negative. Pulmonary lesions were subsequently detected (chest X-ray, CT-scan) and the disseminated tuberculosis was confirmed by a positive culture with acid-fast bacilli in urine, blood, and pulmonary sample. Antituberculosis treatment resulted in the complete resolution of the oral lesion. CONCLUSION: Biopsy for histopathological diagnosis, acid-fast stains and culture, is essential to determine the exact nature of chronic oral ulceration to distinguish between oral malignancy, infectious (syphilis), traumatic, or aphthous ulcers. Tuberculosis of the tongue is a difficult diagnosis. However it should be searched for because treatment usually results in a rapid recovery.     

Delayed tuberculosis diagnosis and tuberculosis transmission.

SETTING: Tuberculosis (TB) patients and their close contacts reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001. OBJECTIVES: A recent prospective study found that 49% of pulmonary TB patients had total treatment delays > or = 90 days. This cohort was analyzed to determine the association between total treatment delay and TB transmission. DESIGN: TB patient data were collected as part of a prospective cohort study; contact data were collected from local health departments. RESULTS: Close contacts of 54 US-born patients (n = 310) and those of 70 foreign-born cases (n = 393) received tuberculin skin tests (TSTs). Among contacts of US-born patients with a total treatment delay of > or = 90 days, 40% had positive TSTs vs. 24% contacts of patients with shorter delays (aOR 2.34; P = 0.03). Other patient factors associated with TST positivity among contacts of US-born cases were black race (aOR 3.03; P = 0.05), sputum smear positive for AFB (aOR 3.29; P = 0.01) and chest radiograph with cavitation (aOR 3.11; P = 0.01). No associations were observed between foreign-born patients and risk of TST positivity among their contacts. CONCLUSION: Among US-born patients, delay in TB diagnosis is associated with greater transmission of infection to contacts and could be used independently of other index patient factors to identify contacts at greatest risk of TB infection.     

Newer diagnostics for tuberculosis and multi-drug resistant tuberculosis

PURPOSE OF REVIEW: This article will review some of the recent developments for the rapid diagnosis and detection of drug resistance in tuberculosis. RECENT FINDINGS: Tuberculosis remains one of the major causes of death from a single infectious agent worldwide. Of great concern for tuberculosis control is the emergence of drug resistance since there is no cure for some multidrug-resistant strains of M. tuberculosis, and there is concern that they may spread around the world, stressing the need for additional control measures such as new diagnostics and better drugs for treatment. Recent advances in molecular biology and a better understanding of the molecular basis of drug resistance have provided new tools for rapid tuberculosis diagnosis. Other non-conventional diagnostic approaches have also been proposed. Nucleic acid amplification techniques, both commercial and in-house, and non-molecular methods are being evaluated. The overall accuracy of most of these tests is promising and some of them can be easily implemented in clinical mycobacteriology laboratories. SUMMARY: New genotypic and phenotypic methods for rapid diagnosis and detection of drug resistance have been developed and tested both in M. tuberculosis strains as well as in clinical samples. Further controlled evaluations are necessary in high-endemic countries for their eventual implementation in the routine diagnostic systems.