Comparison of Xpert MTB/RIF, Real Amp, and CPA Tests in Detecting Mycobacterium tuberculosis

Today, tuberculosis (TB) remains a global public health threat associated with significantly high rates of morbidity and mortality. The World Health Organization's (WHO) Global Tuberculosis Report 2018[1] has reported that in 2017, 10.0 million people across the world had developed TB diseases that resulted in an estimated 1.6 million deaths, and 889, 000 people developed TB in China that led to 39, 000 TB-related deaths. Therefore, rapid and accurate detection of Mycobacterium tuberculosis (MTB) is important for initiating early treatment and reducing mortality. Traditional diagnostic methods for pulmonary TB incorporate chest radiography and sputum smear microscopy;however, several cases of tuberculosis go undiagnosed because of the low sensitivity of smear microscopy[2].

结核分枝杆菌耐热抗原(MTB-HAg)对γδ T细胞影响的研究进展

结核分枝杆菌耐热抗原(MTB-HAg)是从结核分枝杆菌(MTB)减毒菌株H37Ra经121℃,20 min,高温高压处理后从菌体释放到上清液中一种多肽类抗原。γδ T细胞是一类广泛分布于非淋巴组织的非常规T细胞,可分泌肿瘤坏死因子α(TNF-α)、γ干扰素(IFN-γ)等细胞因子,在抗MTB感染的免疫应答中发挥重要作用。MTB-HAg可在体外有效刺激γδ T细胞增殖活化,使其更加高效地参与抗结核感染的过程,故MTB-HAg可作为设计新型结核疫苗或药物的潜在靶点。但由于MTB-HAg组成复杂,具体是何种成分刺激γδ T细胞发挥抗MTB感染功能还不清楚。

Diagnostic Evaluation of GeneXpert MTB/RIF Assay for the Detection of Rifampicin Resistant Mycobacterium tuberculosis among Pulmonary Tuberculosis Patients in Bangladesh

Background: The emergence of multidrug resistant tuberculosis (MDR-TB) and extensively drug- resistant tuberculosis (XDR-TB) has highlighted the need for early accurate detection and drug susceptibility. Objective: The purpose of the present study was to evaluate the accuracy of GeneX-pert MTB/RIF assay for the detection of Mycobacterium tuberculosis and rifampicin resistance. Methodology: This cross sectional study was done in the Department of Microbiology at Sir Salimullah Medical College, Dhaka and National Institute of Chest Disease & Hospital (NIDCH), Dhaka during the period of January 2014 to December 2014 for a period of 1 (one) year. Sputum samples from suspected MDR-TB patients were collected by purposive sampling technique from OPD of Sir Salimullah Medical College (SSMC) and NIDCH. Microscopy, liquid culture in liquid MGIT 960 media and GeneXpert MTB/RIF were done for MTB diagnosis and detection of rifampicin resistance. MGIT 960 media were also used for determination of drug resistance. Result: Liquid culture yielded higher growth (68%) from 100 samples while GeneXpert MTB assay showed similar result (67% positive and 33% negative). Drug susceptibility test in MGIT 960 media showed that out of 68 positive cases Rifampicin resistant cases were 15 (22.05%) whereas GeneXpert MTB assay detected 14 (20.89%) were Rifampicin resistant out of 67 MTB positive samples. When compared to liquid culture the calculated sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy of GeneXpert MTB were 98.52%, 100%, 96.96%, 100% and 99%. Conclusion: GeneXpert MTB/RIF assay is high detection rate of pulmonary tuberculosis and multidrug resistant tuberculosis.

Tuberculosis:an experience from Mycobacterium smears and culture analysis

Objective:Simple tests like direct smear of the acid fast bacilli(AFB) and Mycobacterium culture could assist the diagnosis of tuberculosis.This study is aimed at reviewing the outcome of smears,culture results and contamination rate among specimens requested for AFB smear and Mycobacterium culture.Methods:Retrospective laboratory data analysis requesting for Mycobacterium culture from January 2005 till December 2006 was done in a tertiary teaching hospital of Universiti Sains Malaysia,Kubang Kerian,Kelantan,Malaysia.Results: Four hundred and sixty seven(36.6%) isolates grew from 1 277 specimens.Of these isolates,314 (67.2%) grew Mycobacterium tuberculosis,23(4.9%) grew Mycobacterium other than tuberculosis and 38 (8.1%) grew contaminants.Among the M.tuberculosis cultures,165(52.5%) had growth of more than 100 confluent colonies,whereas 39 cultures(12.4%) had growth of less than 19 colonies.Direct smear for AFB among smear positive cases showed presence of more than 50 bacilli/line in 231(49.5%) cases and smear negative cases accounted for 63(13.5%).Among smear positive cases,291(94.5%) cultures grew Mycobacterium species and another 17(5.5%) cultures grew contaminants.In smear negative cases,32(62.7%) cultures grew Mycobacterium species and 19(37.3%) cultures grew contaminants.Conclusion:The results from data analysis of the Mycobacterium cultures should be critically utilized in order to review the laboratory performance and to improve its services in the future.Some of the data is also useful to the administrators of the hospital in terms of estimating the risk of occupational hazard faced by the health care workers.

Surgical Management of Mitral Valve Infective Endocarditis with Accidental Finding of Open Pulmonary Tuberculosis

Objective: This case report aimed to highlight intersections of TB and Cardiovasular diseases which carry high morbidity and mortality rates. Methods: We are reporting the surgical management of forty seven years female who had back ground history of IDDM (Insulin dependent diabetic Mellitus), ESRD (End stage renal disease) on HD (haemodialysis) also she had left subclavian artery stenosis, and paroxysmal atrial fibrillation. She was diagnosed with mitral valve infective endocarditis and found accidently to have an open pulmonary tuberculosis (TB) on the day before surgery. Results: She was started on first line anti-TB treatment. She was isolated in her private room and airborne precautions measures applied. The patient underwent a tissue Mitral Valve replacement and tricuspid valve repair annuloplasty. Special precautions were applied in Theatre and on cardiopulmonary bypass Machine guided by KAMC-J disinfection protocol. The patient made good recovery postoperatively. She was discharged well on day 7 post operatively. Conclusion: Intersections of TB and cardiovasular diseases carry high morbidity and mortality rates. Early diagnosis and early anti tuberculosis treatment can surely improve the patient prognosis. Our decontamination and disinfective procedures are recommended. Cases like this should be monitored long term for the development of further cardiovascular complication.

Xpert MTB/RIF技术在肺结核患者结核分枝杆菌鉴定及利福平耐药检测中的应用价值

目的分析Xpert MTB/RIF技术在结核分枝杆菌鉴定及利福平耐药性的检验效能及临床应用价值。方法收集感染科初诊疑似肺结核患者痰液样本,以临床确诊为金标准,评估涂片荧光染色法、Xpert MTB/RIF、液体培养法对结核分枝杆菌检测效能。以比例法药敏试验为金标准,评估Xpert MTB/RIF技术对结核分枝杆菌利福平耐药性检验效能。结果2019年5月至2021年5月初诊疑似肺结核患者593例,确诊肺结核141例,非结核分枝杆菌感染14例,其他肺部感染438例。593例疑似肺结核患者中,三种方法检测阳性率分别为:荧光染色法16.7%,Xpert MTB/RIF法23.4%,液体培养法23.6%。141例确诊肺结核患者中男性占比75.2%,其中涂片法敏感性为58.9%低于Xpert MTB/RIF 98.6%和液体培养法99.3%,涂片法特异性为96.46%、Xpert MTB/RIF和液体培养法特异性均为100%。Xpert MTB/RIF和液体培养法检测MTB一致性Kappa值均>0.99。以140株培养阳性结核杆菌比例法药敏试验结果为金标准,Xpert MTB/RIF法检测利福平耐药敏感性87.5%、特异性100%、准确性99.3%,与比例法药物敏感性试验结果一致性Kappa值0.93,结核杆菌利福平耐药率女性(8.6%)高于男性(4.8%)。结论临床确诊肺结核患者中Xpert MTB/RIF检测结核分枝杆菌一致性高、操作简单、敏感性与特异性好,对利福平耐药性检测与比例法比较结果符合率高。Xpert MTB/RIF可作为快速检测MTB及利福平耐药性的有效方法,并可为临床快速选择治疗方案提供参考。

Gene X-pert MTB/RIF检测对肺结核病的诊断价值研究

目的 研究分析肺结核病应用Gene X-pert MTB/RIF检测的诊断价值。方法 选取2022年3—10月在本院就诊的疑似肺结核病患者164例为研究对象,所有患者均给予结核分枝杆菌培养检查、痰涂片抗酸染色法诊断、Gene X-pert MTB/RIF检测,以结核分枝杆菌培养检查结果为金标准,比较痰涂片抗酸染色法诊断与Gene X-pert MTB/RIF检测的阳性率以及诊断准确性、灵敏度、特异度。结果 痰涂片抗酸染色法诊断阳性率为21.34%(35/164),Gene X-pert MTB/RIF检测阳性率为35.98%(59/164),Gene X-pert MTB/RIF检测明显高于痰涂片抗酸染色法诊断(P<0.05)。痰涂片抗酸染色法诊断的准确性为85.37%,灵敏度为59.65%,Gene X-pert MTB/RIF检测的准确性为95.12%,灵敏度为94.74%,Gene X-pert MTB/RIF检测明显高于痰涂片抗酸染色法诊断(P<0.05)。结论 在肺结核病诊断中,Gene X-pert MTB/RIF检测的阳性率更高,同时诊断准确率与灵敏度也更高,为肺结核病的诊断与治疗提供了可靠的指导依据。

γ-干扰素释放试验、Xpert MTB/RIF联合检测诊断艾滋病合并肺结核的价值分析

目的:分析γ-干扰素释放试验联合利福平耐药结核分枝杆菌实时荧光定量核酸扩增检测技术(Xpert MTB/RIF)诊断艾滋病合并肺结核的价值。方法:选取2018年1月-2021年12月苏州市第五人民医院收治的126例艾滋病疑似合并肺结核患者作为研究对象,均进行结核分枝杆菌培养、γ-干扰素释放试验与Xpert MTB/RIF检测,以结核分枝杆菌培养结果为“金标准”,比较不同诊断方式的效能。结果:结核分枝杆菌培养结果显示,126例艾滋病患者中,36例(28.57%)诊断为肺结核。联合检测诊断艾滋病合并肺结核的灵敏度、准确度、阴性预测值高于γ-干扰素释放试验、Xpert MTB/RIF单一检测,差异有统计学意义(P<0.05);γ-干扰素释放试验、Xpert MTB/RIF检测单项诊断艾滋病合并肺结核的灵敏度、准确度、阴性预测值以及三种方式诊断艾滋病合并肺结核的特异度、阳性预测值比较,差异无统计学意义(P>0.05)。结论:γ-干扰素释放试验联合Xpert MTB/RIF诊断艾滋病合并肺结核的效果较好,可作为辅助诊断艾滋病合并肺结核的方法。

Diagnosis of Mycobacterium tuberculosis using molecular biology technology

Objective:To present an integrated molecular biology dedicated system for tuberculosis diagnosis.Methods:One hundred and five sputum specimens from patients strongly suspected by clinical parameters of tuberculosis were studied by Ziehl-Neelsen staining,by cultivation on solid medium and by a balanced hemincsted fluorometric PCR system(Orange C3TB) that could preserve worker safety and produce a rather pure material free of potential inhibitors. DNA amplification was performed in a low cost tuberculosis termocycler-fluorotneter.Produced double stranded DNA was flurometrically detected.The whole reaction was conducted in one single tube which would not be opened after adding the processed sample in order to minimize the risk of cross contamination with amplicons.Results:The assay was able to delect 30 bacillus per sample mL with 99.8%interassay variation coefficient.PCR was positive in 23(21.9%) tested samples(21 of them were smear negative).In our study it showed a preliminary sensitivity of 94.5%for sputum and an overall specificity of 98.7%.Conclusions:Total run time of the test is 4 h with 2.5 real working time.All PCR positive samples are also positive by microbiological culture and clinical criteria.Results show that it could be a very useful tool to increase detection efficiency of tuberculosis disease in low bacilus load samples.Furthermore,its low cost and friendly using make it feasible to run in poor regions.

Stool as Appropriate Sample for the Diagnosis of <i>Mycobacterium</i><i>tuberculosis</i>by Gene Xpert Test

Background: Diagnosis of pediatric pulmonary tuberculosis (PTB) is a challenge. Symptoms are nonspecific. Young children are unable to expectorate sputum samples;the procedures for obtaining respiratory samples are invasive. Thus Mycobacterium tuberculosis cultures and smears often are not performed. Stool samples were used as an alternative to respiratory samples for the diagnosis of pediatric PTB using stool Xpert MTB/RIF and its sensitivity for detecting the DNA of MTB in stool was determined. Methods: The study was a laboratory-based cross-sectional prospective design. Stool specimen was collected from PTB suspected children (<15 years) attended in Gertrude’s Children’s Hospital Nairobi and Kiambu District Hospital from September 2013 to March 2014. Stool for Xpert was processed in two ways, direct and prior extraction of DNA using QIAGEN stool DNA extraction kit. Result: A total sample of 91 stool specimen was collected from patients. Of these 53 (58.2%) had sputum ZN smear microscopy. Six (11.3%) of them were confirmed smear positive for PTB. Stool Gene Xpert was positive in all the six smear positive children. Four (7.5%) smear negative patients tested positive by stool Gene Xpert test. This association is significant (P = 0.000). Conclusion: This study reports that Mycobacterium tuberculosis DNA can be detected in stool using Xpert testing with a higher sensitivity. Therefore stool which can easily be obtained is an appropriate alternative sample for the diagnosis of PTB using Xpert assay for children unable to give respiratory samples. Furthermore Xpert turn round time is less than 2 hours.

Xpert MTB/RIF与结核分枝杆菌利福平耐药表型检测一致性分析

目的探讨Xpert MTB/RIF和表型药物敏感性试验(pDST)检测结核分枝杆菌(MTB)利福平(RFP)耐药性结果的一致性,以及产生不一致结果的原因。方法对2020年云南省耐药监测中行Xpert MTB/RIF检测的672株MTB进行比例法pDST,对2种方法结果不一致的菌株进行全基因组测序(WGS)。结果以pDST结果为标准,XpertMTB/RIF检测MTBRFP耐药的敏感性为94.44%,特异性为97.32%,阳性预测值为66.67%,阴性预测值为99.52%。672株MTB中,有19株(2.83%)Xpert MTB/RIF与pDST检测结果不一致。2株Xpert MTB/RIF显示RFP敏感,pDST显示RFP耐药菌株中,未检出耐药突变1株,检出rpoB-Ile491Phe突变1株;17株Xpert MTB/RIF显示RFP耐药,pDST显示RFP敏感菌株均发现RFP耐药相关突变。Xpert MTB/RIF与pDST检测结果不一致的19株MTB均未发现明显的异质性耐药情况。结论Xpert MTB/RIF与pDST检测MTB RFP耐药结果一致性较好。结果不一致的主要原因为pDST结果的不稳定性、部分rpoB基因突变与RFP耐药相关性差,以及少数菌株发生了Xpert MTB/RIF靶点以外的其他罕见突变。

Xpert MTB/RIF Ultra在快速检测结核分枝杆菌和利福平耐药中的应用

目的探讨Xpert MTB/RIF Ultra在快速检测结核分枝杆菌和利福平耐药中的应用价值。方法收集2019年12月至2020年5月就诊于福州肺科医院的447例疑似肺结核患者的痰标本,分别进行MGIT960液体培养及药敏、Xpert MTB/RIF(Xpert)和Xpert Ultra检测,将检出MTB的菌株和痰液进行rpoB基因Sanger测序。以临床诊断结果为参照,比较MGIT960液体培养、Xpert、Xpert Ultra检测MTB的敏感度和特异度;分别以液体药敏和测序结果为金标准,评价Xpert Ultra检测MTB利福平耐药性的效能。结果以临床确诊为参照,Xpert Ultra敏感度高于液体培养和Xpert,差异有统计学意义(χ^(2)=28.97、164.86,P均<0.05),特异度与液体培养和Xpert比较差异无统计学意义(P均>0.05)。分别以利福平液体药敏表型结果和rpoB基因测序结果为金标准,Xpert Ultra的敏感度为88.89%和93.75%。同时经测序分析,35例利福平耐药样本中,rpoB的531位点突变最为常见,占48.57%。结论Xpert Ultra能快速检测痰液中的MTB及其利福平耐药性,对肺结核早期诊疗有良好的临床应用价值,适合在各级实验室推广。

Evaluation of Xpert MTB/RIF Ultra for Diagnosis of Extrapulmonary Tuberculosis: A Retrospective Analysis in a Low-Tuberculosis Prevalence Setting

Background: Extrapulmonary tuberculosis (EPTB) remains difficult to diagnose because the clinical specimens to be examined are often paucibacillary and obtained with difficulty from inaccessible sites. An updated Xpert® MTB/RIF Ultra (Ultra) test has been designed and licensed to improve sensitivity in the detection of Mycobacterium tuberculosis complex. The aim of the present study is to evaluate the performance of Ultra assay for the clinical diagnosis of EPTB in a low tuberculosis prevalence country. Methods: A retrospective analysis was performed at “A. O dei Colli” of Naples on consecutive extrapulmonary specimens for EPTB across a three-year period. All different types of extrapulmonary specimens were tested for EPTB by smear microscopy, culture and Ultra assay in accordance with relevant guidelines. Results: A total of 606 EPTB samples, 561 culture negative EPTB and 45 culture positive EPTB were included. Using culture as reference standard, the overall sensitivities and specificities of Ultra assay were 95.6% (95% CI 84.8 - 99.5) and 97.5% (95% CI 95.8 - 98.6) respectively. Sensitivity and specificity of Ultra for individual category of specimens were also performed. Conclusion: In a low-tuberculosis prevalence setting, Ultra assay confirms to have a good performance in the diagnosis of EPTB for all different extrapulmonary samples.

Gene Xpert MTB/RIF联合痰涂片检查在肺结核诊断中的效能分析

目的:分析GeneXpert MTB/RIF联合痰涂片检查在肺结核诊断中的效能。方法:选取2020年1月至2022年12月于漳州市长泰区接受筛查的152例疑似肺结核患者进行前瞻性研究,均进行痰涂片和GeneXpert MTB/RIF检查,统计单项及联合检查对肺结核的检出结果,并以痰培养结果为金标准,比较单项和联合检查诊断肺结核的效能。结果:痰培养结果显示,152例疑似肺结核患者中,阳性121例,阴性31例;痰涂片检查检出阳性79例,阴性73例;GeneXpert MTB/RIF检查检出阳性112例,阴性40例;联合检查检出阳性122例,阴性30例;GeneXpert MTB/RIF检查诊断肺结核的准确率、灵敏度、特异度、阴性预测值和阳性预测值均高于痰涂片检查,差异有统计学意义(P<0.05);GeneXpert MTB/RIF联合痰涂片检查诊断肺结核的准确率、灵敏度和阴性预测值均高于二者单项检查,差异有统计学意义(P<0.05)。结论:GeneXpert MTB/RIF联合痰涂片检查诊断肺结核的效能优于二者单项检查。

GeneXpert MTB/RIF检出量与结核分枝杆菌培养和利福平表型耐药的关系

目的探讨痰液GeneXpert MTB/RIF(Xpert)检出量与结核分枝杆菌(MTB)培养阳性率和利福平耐药表型的关系。方法选取2016年4月—2019年12月温州市中心医院痰液Xpert检测为利福平耐药的初治肺结核患者183例。比较不同Xpert检出量患者MTB培养阳性率和利福平耐药表型假阳性率的差异。结果183例患者中,痰液Xpert检出量为高、中、低、极低的患者分别有48、46、56、33例。有80.87%(148/183)的患者MTB培养阳性。148例MTB培养阳性患者对一线抗结核药物异烟肼、利福平、乙胺丁醇、链霉素的耐药率分别为79.05%(117/148)、81.08%(120/148)、27.03%(40/148)、52.70%(78/148);对4种药物全敏感的患者11例,全耐药26例;单种药物耐药24例,以单耐利福平最常见(17例);耐2种药物34例,以耐利福平和异烟肼最常见(25例);耐3种药物53例,以耐利福平、异烟肼、链霉素最常见(40例)。Xpert检出量为极低、低、中、高的患者MTB培养阳性率分别为48.48%、76.79%、93.48%、95.83%,不同Xpert检出量患者MTB培养阳性率差异有统计学意义(P<0.001)。Xpert检出量为极低、低、中、高的患者利福平耐药表型假阳性率分别为43.75%、23.26%、13.95%、10.87%,不同Xpert检出量患者利福平耐药表型假阳性率差异具有统计学意义(P=0.022)。结论痰液Xpert检测可减少肺结核患者的漏诊,但检出量较低时,易出现MTB培养假阴性、利福平耐药假阳性。

五种检测技术在尘肺合并肺结核诊断中的应用价值

目的探讨痰涂片找抗酸杆菌、痰利福平耐药实时荧光定量核酸扩增检测技术(Xpert MTB/RIF)、分枝杆菌菌种鉴定、痰抗酸杆菌培养和血γ-干扰素释放检测技术(TB-IGRA)5种检测技术在尘肺合并肺结核临床诊断中的应用价值。方法纳入2016年7月—2021年5月在厦门大学附属第一医院住院治疗的尘肺合并肺结核患者,按照尘肺患者是否合并肺结核,将患者分为尘肺组(156例)和尘肺合并肺结核组(111例);比较两组患者的性别、年龄、接尘时间等一般资料,以及患者痰涂片、Xpert MTB/RIF、分枝杆菌菌种鉴定、痰培养和TB-IGRA的检测结果,分析尘肺合并肺结核患者5种检测技术阳性检出率的差异及其诊断价值。结果在尘肺合并肺结核组中,TB-IGRA检测方法的阳性检出率最高(81.1%),高于其他4种检测方法(P<0.01);两两联合检测,以Xpert MTB/RIF+TB-IGRA组合的检测方式检出率最高(96.4%),高于其他9种组合(P<0.01)。结论TB-IGRA检测方法对尘肺合并肺结核患者的阳性检出率较高,联合Xpert MTB/RIF检测后可进一步提高诊断效率,对早期诊断尘肺是否合并结核具有重要的临床诊断价值。

云南省昭通地区结核分枝杆菌临床分离株遗传多样性和耐药分子特征

目的调查云南省昭通地区结核分枝杆菌(Mycobacterium tuberculosis,MTB)临床分离株的遗传多样性和耐药分子特征。方法2022年9月—2023年8月从昆明医科大学附属昭通医院收治的298例涂阳肺结核患者中共采集了MTB 298株,用MeltPro TB测定法通过荧光聚合酶链反应(polymerase chain reaction,PCR)熔解曲线法鉴定所有分离株。用多色熔解曲线分析技术进行间隔区寡核苷酸分型(interval oligonucleotide typing,Spoligotyping)。用分枝杆菌散布重复单元(mycobcterial interspersed repetitive units,MIRU)-可变数目串联重复序列分型(variable number of tandem repeat typing,VNTR)(MIRU-VNTR)24位点分型法进行基因分型。使用PCR和靶向测序检测耐药基因突变。结果北京菌株占所有MTB菌株的69.80%(208/298)。其他谱系包括T、LAM、MANU2、CAS、NEW-1和SITVITWEB数据库中未发现的孤儿型,分别占5.70%(17/298)、3.36%(10/298)、0.67%(2/298)、0.34%(1/298)、8.39%(25/298)及11.74%(35/298)。北京菌株对左氧氟沙星的耐药率略高于非北京菌株(P=0.042),而北京菌株与非北京菌株2种基因型菌株对异烟肼、利福平、乙胺丁醇、链霉素、吡嗪酰胺、卡那霉素耐药率差异无统计学意义(P>0.05)。MIRU-VNTR 24位点分型分析结果显示,33个菌株可分为13株聚类,其聚类率为39.39%。每个等位基因的Hunter-Gaston指数在0~0.814之间,其中18个位点对非北京菌株具有中高鉴别能力。但只有10个位点对北京菌株具有中高鉴别能力。结论MTB菌株在中国云南省昭通地区表现出较高的遗传多样性,北京菌株是MTB和耐药结核病菌株的优势谱系。

Gene Xpert-MTB/RIF检测法在结核病诊断中的意义

目的探讨Gene Xpert-MTB/RIF检测结核分枝杆菌及利福平耐药性在结核病诊断中的作用。方法收集2017年8月至2017年12月在我院住院的202例结核病患者,对其痰标本分别行痰涂片、痰培养、比例法体外药敏试验和Gene Xpert-MTB/RIF法检测,并对Xpert-MTB/RIF检测结果进行分析。结果 Xpert MTB/RIF阳性率及痰培养阳性率明显高于痰涂片,差异有统计学意义;而Xpert MTB/RIF阳性率与痰培养阳性率比较,差异无统计学意义;以痰培养为金标准,Xpert MTB/RIF检测结核分枝杆菌及利福平耐药的敏感度分别为75.9%和66.7%,特异度分别为82.8%和100.0%。Xpert MTB/RIF及传统比例法检测利福平耐药一致性好。结论 Xpert检测与传统方法相比快捷,并具有更高灵敏度及特异度,可为临床诊断、选择耐药结核的治疗方案提供参考。

Xpert MTB/RIF在快速诊断肺结核及利福平耐药中的临床应用

目的探讨利福平耐药实时荧光定量核酸扩增检测技术(Xpert MTB/RIF)在肺结核诊断及其耐药性检测中的临床应用价值。方法收集408例结核患者标本,同时采用抗酸染色法、固体培养法及Xpert MTB/RIF检测,并对其结果进行分析比较。结果 408例标本抗酸染色法、固体培养法和Xpert MTB/RIF检测出结核分枝杆菌的阳性率分别为25.00%(102/408)、42.16%(172/408)和58.09%(237/408)。经统计学分析,Xpert MTB/RIF阳性率高于抗酸染色法和固体培养法,差异均有统计学意义(P<0.05)。其中,固体培养法和Xpert MTB/RIF检测均为阳性的标本共168例,经比例法药物敏感试验与Xpert MTB/RIF检测利福平耐药率分别为26.19%(44/168)和27.38%(46/168),2种方法耐药率比较,差异无统计学意义(P>0.05),以比例法药敏试验作为金标准,Xpert MTB/RIF检测利福平耐药的敏感度为97.73%(43/44),特异性为97.58%(121/124)。结论 Xpert MTB/RIF可快速、准确检测结核分枝杆菌及利福平耐药性,具有重要的临床应用价值。

结核分枝杆菌(MTB)异质性耐药研究进展

异质性耐药,是指在同一样本中同时存在耐药菌和敏感菌的现象,这体现了细菌群体从部分耐药向完全耐药转变的过程。研究异质性耐药对于认识耐药结核病的发展过程,以及评估治疗方案和指导临床用药具有重要的意义。本文对结核分枝杆菌(Mycobacterium tuberculosis,MTB)异质性耐药的产生及其对临床的影响进行了综述。