Evaluation of the FASTPlaqueTB assay for direct detection of Mycobacterium tuberculosis in sputum specimens.

SETTING: Sputum samples were collected from suspected tuberculosis patients attending out-patient clinics at the Ojha Institute of Chest Diseases, Karachi, Pakistan. OBJECTIVE: To evaluate the performance of the FASTPlaqueTB assay for rapid diagnosis of pulmonary tuberculosis. DESIGN: A comparative study of 584 sputum samples using acid-fast smear microscopy, Lowenstein-Jensen culture and FASTPlaqueTB. RESULTS: A total of 514 samples yielded complete results. Seventy specimens were lost to analysis due to the overgrowth of contaminants. The addition of antimicrobials inhibited growth of gram-positive contaminants, and reduced the overall contamination rate from 18.2% to 7.2%. Mycobacterium tuberculosis was isolated from 175 smear-positive and 70 smear-negative specimens. FASTPlaqueTB detected M. tuberculosis in 81.6% of specimens, with a specificity of 97.7%. The sensitivity and specificity of the assay for smear-positive specimens were respectively 87.4% and 88.2%. For smear-negative specimens, the sensitivity of the assay was 67.1% and the specificity was 98.4%. The combined sensitivity of smear and FASTPlaqueTB for M. tuberculosis was 90%. Test results were available in 48 hours. CONCLUSION: FASTPlaqueTB is a sensitive and specific test for rapid diagnosis of pulmonary tuberculosis in high prevalence areas. The test is sensitive enough to confirm a large number of clinically suspected smear-negative cases and improve case finding.     

Effectiveness of the BDProbeTec ET system for detection of Mycobacterium tuberculosis complex in sputum and bronchoalveolar lavage specimens

ObjectiveThe diagnostic efficacy of the BDProbeTEC ET Mycobacterium tuberculosis (MTB) complex direct detection assay (DTB) performed on bronchoalveolar lavage (BAL) specimens and sputum smears was compared with acid-fast bacilli (AFB) smear microscopy.MethodAFB smear microscopy, DTB and culture results of 286 patients with pulmonary tuberculosis were retrospectively reviewed. A total of 120 patients provided expectorated sputum samples, and 166 patients provided BAL specimens. Culture results and clinical diagnosis were used as gold standards.ResultsThe sensitivity and specificity of the DTB assay in detecting MTB in sputum specimens was significantly higher compared to AFB smear microscopy (83.7% and 82.4%, vs. 75.6%, and 41.2%, respectively). The sensitivity and specificity of the DTB assay in detecting MTB in sputum samples was 77.2% and 100% compared to clinical diagnosis, while AFB smear had a sensitivity and specificity of 70.3% and 26.3%, respectively. Compared to culture, DTB had a sensitivity and specificity of 82.8% and 93.2%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 41.9% and 87.7%, respectively. Compared to clinical diagnosis, DTB had a sensitivity and specificity of 67.2% and 100%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 34.8% and 79.5%, respectively.ConclusionsThe superior performance of the DTB assay relative to AFB smear microscopy makes it a valuable tool to enable early diagnosis of MTB, thereby improving patient care and reducing transmission.     

How many sputum specimens are necessary to diagnose pulmonary tuberculosis?

The definitive diagnosis of pulmonary tuberculosis (PTB) relies on identifying or culturing Mycobacterium tuberculosis from respiratory specimens. National guidelines have recommended obtaining 3 sputum specimens from patients with suspected tuberculosis, but there has been little data on the number of specimens actually needed to support a diagnosis. We retrospectively reviewed all patients diagnosed with PTB at a public inner-city hospital and assessed the sensitivity of the acid-fast bacilli (AFB) smear and the number of smears needed to establish the diagnosis. Between January 1, 1997 and October 1, 2000, 425 patients were diagnosed with culture-proven PTB. Acid-fast bacilli (AFB) smears and cultures were performed on 951 respiratory specimens from 425 patients. The overall sensitivity of a positive AFB smear increased from 67% with 1 sputum collected to 71% and 72%, respectively, with the second and third specimens. The sensitivity of smears from 239 HIV-negative patients was 75%, 79%, and 80% with 1, 2, and 3 smears, respectively, collected compared with 57%, 61%, and 62%, respectively, for 142 HIV-positive patients. In summary, 2 respiratory specimens proved adequate in establishing a diagnosis of tuberculosis, and the third specimen added little additional diagnostic value.     

A minimum 5.0 ml of sputum improves the sensitivity of acid-fast smear for Mycobacterium tuberculosis

Detection of acid-fast bacilli (AFB) by sputum smear supports treatment decisions with pulmonary tuberculosis (TB), but smear sensitivity for Mycobacterium tuberculosis is only approximately 45 to 75%. In an effort to increase sensitivity, smears were prepared using a minimum sputum volume of 5.0 ml. Sensitivity of smears during a 39-mo period (n = 1,849) using >/= 5.0 ml of sputum was 92. 0%, significantly greater (p < 0.001) than a sensitivity of 72.5% in a previous 24-mo period (n = 3,486) when all specimens were processed regardless of volume. All new cases of TB (n = 18) were smear-positive with >/= 5.0 ml of sputum before treatment, and all were receiving antituberculosis drugs at hospital discharge. In contrast, significantly fewer new cases of TB (14 of 26, p = 0.002) were positive before treatment when smears were prepared using sputum of any volume, and significantly fewer of these new TB cases (18 of 26, p = 0.03) were receiving treatment at hospital discharge. The eight cases without treatment were smear-negative. These results indicate that acid-fast smear using >/= 5.0 ml of sputum increases sensitivity for M. tuberculosis and accelerates treatment of TB.     

噬菌体裂解法与BACTEC-460法在结核分支杆菌快速检测中的比较

目的：比较噬菌体裂解法与BACTEC－460法在结核分支杆菌快速检测及鉴定中的价值。方法：应用噬菌体裂解法和BACTEC－460法分别检测30株结构分支杆菌临床分离株、10株非结核分支杆菌和7株非分支杆菌，以及60份临床确诊的肺结核患者的痰标本，结果：所有结核分支杆菌临床分离株噬菌体裂解试验均为阳性，而非结核分支杆菌和非分支杆菌均为阴性。41份BACTEC－460培养阳性和19份BACTEC－460培养阴性的痰标本中，噬菌体裂试验分别有34份（82．9％）和5份（26．3％）阳性。结论：噬菌体裂解法可以简便，快速地检测结核分支杆菌，并且具有较高的敏感性的特异性。     

Performance of a rapid phage-based test, FASTPlaqueTB, to diagnose pulmonary tuberculosis from sputum specimens in South Africa.

SETTING: Twelve primary health care clinics in the South Peninsula Administration, Cape Town, Western Cape Province, South Africa. OBJECTIVE: To evaluate the performance of FAST-PlaqueTB, a new phage-based test, for the rapid diagnosis of TB in individuals with no previous history of TB treatment presenting at primary health care clinics in Cape Town, South Africa. DESIGN: A comparative study of FASTPlaqueTB, auramine smear microscopy and Lowenstein-Jensen culture of 1692 decontaminated sputum specimens from 853 patients suspected of having TB. Resolution of discrepant results was undertaken by review of clinical information, chest X-ray and follow-up of treatment outcomes. RESULTS: FASTPlaqueTB detected TB in 75.2% of culture-confirmed cases and 70.3% of all cases with a clinical diagnosis of TB, with a specificity of 98.7% and 99.0%, respectively. The performance parameters of FASTPlaqueTB were significantly superior to those of concentrated auramine smear microscopy (63.4% and 61.3% sensitivity, and 97.4% and 97.3% specificity in culture-confirmed and all cases, respectively). Of those patients with two negative sputum smears, FAST-PlaqueTB detected TB in 54.1% of TB cases confirmed by culture and 48.8% of all cases with a clinical diagnosis of TB. A combination of smear microscopy and FASTPlaqueTB enabled 81.2% of culture-confirmed cases and 78.4% of total TB cases to be detected within 2 days of presentation. CONCLUSION: FASTPlaqueTBTM is a rapid, manual test for the diagnosis of TB. The test has significantly higher sensitivity overall compared with auramine sputum smear microscopy in individuals with no previous history of TB treatment, although smear microscopy did detect the most infectious of the TB cases. The FAST-PlaqueTB test is easy to perform, requires no dedicated equipment, and results are read by eye within 48 hours. This test can be useful for the diagnosis of TB in developing countries with a high burden of TB where other rapid diagnostic tests may not be appropriate. The test shows promising performance, particularly in the diagnosis of smear-negative disease, and could be used in conjunction with smear microscopy to aid in the diagnosis of additional cases of TB.     

液基夹层杯技术检测抗酸杆菌应用性研究

目的评价液基夹层杯技术检测抗酸杆菌的应用价值。方法收集1 190例肺结核可疑症状者的642份晨痰标本和1 140份即时痰标本,每份痰标本均采用液基夹层杯技术、直接涂片查找抗酸杆菌技术和罗氏结核分枝杆菌培养技术进行检测,比较直涂法、液基法与培养法对痰标本的阳性检出率,并在以培养法为金标准的前提下考察液基法、直涂法的灵敏度和特异度,同时评价晨痰和即时痰、1次痰和2次痰对肺结核涂阳病人发现的差异。结果液基法、直涂法和培养法对642份晨痰标本的阳性检出率分别为23.5%、12.7%和26.6%,对1 140份即时痰的阳性检出率分别为18.1%、9.6%和23.3%。以培养法作为金标准,液基法的灵敏度和特异度分别为68.9%和95.8%,并与直涂法相对应的指标差异有统计学意义(P0.05)。液基法检测表明:642份晨痰阳性检出率显著高于1 140份即时痰阳性检出率(P0.05)。结论液基法能够提高痰标本的灵敏度,特异度较高,操作标准化,且所需设备简单,便于基层开展,是一种可能具有推广价值的检测方法。     

The validity of acid-fast smears of gastric aspirates as an indicator of pulmonary tuberculosis.

SETTING: A tuberculosis referral hospital in Canada. OBJECTIVE: To determine the validity of acid-fast (AFB) smears of gastric aspirates (GA) in the diagnosis of pulmonary tuberculosis, and to assess the prevalence of nontuberculous mycobacteria (NTM) in GA isolates from such patients. DESIGN: A retrospective case review of our experience with AFB smears (Kinyoun) and cultures of GA and sputum over a 3-year period. RESULTS: From 1994 to 1996 inclusive, 1155 GA were performed in 889 patients. Mycobacteria were cultured from 109 (9%) GA. Thirteen of these were positive on smear (sensitivity 19%). All GA that were positive on smear were culture positive for Mycobacterium tuberculosis. There were no false positive smears (specificity 100%). The sensitivity and specificity of the sputum smear were 45% and 99%, respectively. Of the 96 culture positive, smear negative GA, 54 grew M. tuberculosis and 42 grew an NTM. Of 13 patients who had sputum and GA studied coincidentally, and in whom the sputum was both smear and culture positive, the GA culture was positive in 13 and the smear was positive in eight (66%). CONCLUSION: AFB smear of GA is a relatively insensitive but highly specific indicator of pulmonary tuberculosis warranting institution of antituberculosis treatment. Gastric AFB smear positivity appears to reflect a high bacillary burden within the respiratory tract.     

结核/非结核分枝杆菌核酸快速检测方法临床应用价值

目的 评价结核/非结核分枝杆菌核酸快速检测方法的临床应用价值。 方法 应用实时荧光PCR技术对420例标本进行临床试验研究,并与抗酸杆菌涂片和分枝杆菌培养方法对照比较。 结果 结核分枝杆菌核酸检测灵敏度为48.5%（其中菌阳标本灵敏度为95.8%,菌阴标本灵敏度为14.5%）,特异度99.3%,阳性预测值为99.1%,阴性预测值为55.5%;临床试验388例痰标本中检测出1例非结核分枝杆菌核酸阳性,经测序确认,准确率100%;同时对32例非结核分枝杆菌临床分离株进行核酸检测,并经测序确认,准确率100%。 结论 应用实时荧光PCR技术,能实现在1支管内同时进行结核分枝杆菌/非结核分枝杆菌的核酸检测。该方法具有简单快速、特异性好污染性少的特点。可作为实验室辅助检测结核/非结核分枝杆菌核酸方法之一。     

Is it appropriate to routinely use a nucleic acid amplification test for the diagnosis of tuberculosis?

The purpose of this study was to compare the usefulness of the nucleic acid amplification (NAA) test against conventional tests under normal laboratory operational conditions. The NAA test was performed on the first sputum specimen of all patients. Liquid media culture, solid media culture, and Ziehl-Neelsen stain for an acid-fast bacilli (AFB) smear were performed on three sputum specimens. The results were calculated using the gold standard of either the culture results or the clinical diagnosis. Of the 593 patients tested, 151 (25.5%) were diagnosed with pulmonary tuberculosis. The sensitivity of the first specimen only was 64% for the NAA test, 54% for the AFB smear, 77% for BACTEC MGIT 960 culture, 40% for Lowestain-Jensen (LJ) culture, and 25% for 7H11 culture. The sensitivity when using all three specimens increased to 63% for AFB smear, 87% for BACTEC MGIT 960 culture, 51% for LJ culture, and 40% for 7H11 culture. The specificity was 100% for all culture tests, 99% for the AFB smear, and 99.5% for NAA test. The mean turnaround time was 1.34 days for NAA, 0.59 days for AFB smear, 11 days for BACTEC MGIT 960 culture, 23 days for LJ culture, and 20 days for 7H11 culture. We conclude that the sensitivity of NAA is still far from ideal, and the test is not cost effective. Thus, the COBAS AMPLICOR PCR system is not suitable for routine use in microbiology laboratories.     

Detection of Mycobacterium tuberculosis DNA from peripheral blood in patients with HIV-seronegative and new cases of smear-positive pulmonary tuberculosis by polymerase chain reaction

Tuberculosis is still one of the most important cause of mortality and morbidity in many countries and there is a need for new methods for accurate and rapid diagnosis of tuberculosis. To determine the sensitivity and specificity of polymerase chain reaction (PCR) method, we have evaluated Mycobacterium tuberculosis DNA in peripheral blood samples with PCR technique in adult patients with human immunodeficiency virus (HIV)-negative and new cases of smear-positive pulmonary tuberculosis. We investigated the relationship between characteristic of the patients, radiological extension of the disease, sputum smear grade, presence of cavity, body-mass index (BMI) serum albumin level, total delay time and PCR positivity. Forty patients (33 male and 7 female; mean age 37.8 +/- 14.1) and 20 healthy control subjects (13 male and 7 female; mean age 35.6 +/- 7.3) were enrolled in this study. PCR was positive in 16 of 40 (40%) patients with pulmonary tuberculosis and negative in 24 of 40 (60%). None of the healthy controls had positive PCR results. The overall sensitivity specificity and accuracy of the PCR assay was 40, 100 and 60%, respectively. We found the positive correlation between PCR positivity and sputum smear grade (r=0.46, P=0.003) radiological extension of the disease (r=0.69, P=0.001), presence of cavity (r=0.90, P=0.001). We conclude that the detection of M. tuberculosis DNA from peripheral blood by PCR technique is useful for the rapid diagnosis of tuberculosis patients with HIV-negative. Hematogenous dissemination was important in tuberculosis patients and peripheral blood samples were suitable and easy materials. However, standardization of the PCR method must be ensured for the diagnosis of tuberculosis.     

Rapid detection of Mycobacterium tuberculosis from sputum specimens using the FASTPlaqueTB test.

OBJECTIVES: To determine the performance of the FASTPlaqueTB test, based on bacteriophage amplification technology, by comparison with the BACTEC 460 TB culture system, the L?wenstein-Jensen (LJ) medium culture method and Ziehl-Neelsen (ZN) staining. METHODS: Of 400 sputum specimens studied in our laboratory, 19 were excluded due to contaminant growth. The FASTPlaqueTB test was performed according to the manufacturer's instructions. RESULTS: Only 42 of the 381 specimens examined were positive on at least one test: 30 were positive with ZN staining, 34 with LJ medium, 36 with the FASTPlaqueTB test and 39 with BACTEC 460 TB. The combination of BACTEC 460 TB and LJ medium culture was considered the gold standard. The sensitivity and specificity were 70.7% and 99.7% for ZN staining, 87.8% and 100% for the FASTPlaqueTB test, 82.9% and 100% for LJ, and 95.1% and 100% for BACTEC 460 TB. CONCLUSIONS: The FASTPlaqueTB test is useful in the rapid diagnosis of TB.     

Induced sputum improves the diagnosis of pulmonary tuberculosis in hospitalized patients in Gaborone, Botswana

SETTING: Low sensitivity of acid-fast bacilli (AFB) sputum smears and absence of productive cough are obstacles to the diagnosis of pulmonary tuberculosis (PTB) in hospitals that lack access to bronchoscopy. OBJECTIVES: To evaluate induced sputum, gastric content, blood and urine specimens to improve PTB diagnosis in patients not diagnosed by expectorated sputum AFB smears. DESIGN: Patients admitted to the medical wards of a large public hospital in Gaborone, Botswana, were prospectively enrolled if they had symptoms consistent with PTB, an abnormal chest radiograph, were treated empirically with anti-tuberculosis chemotherapy or had no improvement on antibiotics, and had a non-productive cough or AFB smear-negative sputum. Induced sputum was stained for AFB and Mycobacterium tuberculosis cultures were performed on induced sputum, gastric contents, urine and blood. RESULTS: Of 140 patients meeting the enrollment criteria, 113 (81%) were human immunodeficiency virus (HIV) positive. Fifty-seven (41%) had PTB based on positive cultures from one or more sites, including 48 (84%) from induced sputum, 17 (30%) urine, 13 (23%) gastric contents and 7 (12%) blood. AFB smears were positive in only 18 (32%) culture-proven PTB cases. CONCLUSION: Induced sputum cultures greatly enhanced M. tuberculosis detection in patients with a high prevalence of HIV/AIDS in a hospital without access to bronchoscopy.     

Factors affecting the clinical value of microscopy for acid-fast bacilli

In order to assess the clinical value of microscopy for acid-fast bacilli (AFB), the results of 3,207 clinical specimens submitted for mycobacterial smear and culture were analyzed. Mycobacteria grew from 176 (5.5%) of the specimens, 95 (54%) of which were Mycobacterium tuberculosis. Although the overall sensitivity of the smear was low (33%), 65% of respiratory specimens yielding M. tuberculosis had positive AFB smears. Furthermore, 96% of patients with pulmonary tuberculosis from whom more than one specimen was processed had at least a single positive AFB smear. Smear sensitivity correlated well with quantitative growth; 89% of specimens yielding greater than or equal to 50 colonies per slant were smear positive. Specificity of the AFB smear was high; 89% of smear-positive specimens had positive cultures. After the results from culture-negative patients known to have active tuberculosis were eliminated from the analysis, the specificity of a positive smear rose to 98.3%. When the results of all specimens from each patient were considered in toto, the AFB smear had a predictive value of greater than or equal to 96%.     

The value of fluorescence microscopy of auramine stained sputum smears for the diagnosis of pulmonary tuberculosis

Laboratory diagnosis of pulmonary tuberculosis rests on the bacteriological examination of sputum smears stained by the Ziehl-Neelsen (ZN) method for acid fast bacilli (AFB). In the present study, we have compared light microscopy of ZN stained smears with that of fluorescence microscopy of sputum smears stained by auramine-phenol flurochrome dye for detection of AFB in sputum specimens. Sputum specimens from a total of 2,600 clinically suspected and diagnosed cases of pulmonary tuberculosis were examined by both the methods. Sputum specimens from a total of 1,104 patients were found to be positive for AFB. These included sputa from 975 (37.5%) patients positive for AFB by both ZN and auramine staining methods and sputa from an additional 129 (4.96%) patients positive for AFB by auramine staining only. Thus auramine staining of sputum smears in comparison to that of ZN staining is a better method of sputum microscopy for demonstration of AFB in sputum specimens. Fluorescence microscopy is relatively more sensitive and has the added advantage of allowing a large number of sputum specimens to be examined in a given time, in laboratories equipped with a fluorescent microscope.     

Integration of microscopy and serodiagnostic tests to screen for active tuberculosis.

SETTING: University of California San Diego Medical Center, USA. OBJECTIVE: To create a simple screening strategy for tuberculosis (TB) that includes antibody detection assays to improve the accuracy of microscopic examination of sputum for acid-fast bacilli (AFB smear). METHODS: Serum samples were obtained from 190 patients suspected of having active TB. TB diagnosis was established by Mycobacterium tuberculosis culture. HIV status was determined by commercial serologic tests. IgG antibody levels were measured by ELISA using purified M. tuberculosis antigens. Data from 130 randomly selected patients were used to develop a screening strategy; data from the remaining 60 patients were used for validation. RESULTS: AFB smear had 70% sensitivity and 88% specificity. In algorithms integrating single or multi-antigen ELISA with AFB smear and HIV results, the sensitivity improved over each test alone. The algorithm that included a four-antigen ELISA (38 kDa antigen, lipoarabinomannan, MPT-64 and glutamine synthase) had a sensitivity of 93% and a specificity of 76%. Compared to AFB smear, the sensitivity of the algorithm was significantly higher, while the specificity was not statistically different. CONCLUSION: This study demonstrates that a screening strategy can be created by integrating multi-antigen ELISA with AFB smear and HIV testing.     

Evaluation of the concentration sputum smear technique for the laboratory diagnosis of pulmonary tuberculosis

The microbiological diagnosis of pulmonary tuberculosis (PTB) plays a key role in routine and Tuberculosis (TB) Control Programmes in developing countries. Concentration of acid-fast bacilli (AFB) in clinical specimens is an important step in the laboratory diagnosis of mycobacterial diseases. Microscopy of smears of sputum by direct and after mechanical sedimentation and centrifugation methods followed by treatment with 5% sodium hypochlorite (NaOCl) solution for concentration of the organisms were compared and evaluated.The rate of recovery of AFB from sputum was 8.5%, 25.5% and 38.0% for direct smear microscopy, concentration by sedimentation of NaOCl-treated sputa followed by Ziehl-Neelsen staining and concentration by centrifugation after use of NaOCl respectively. Both the concentration methods by the use of NaOCl solution increased the yield of theAFB by more than threefold compared with the direct microscopy of sputum (P < 0.05). The concentration methods by sedimentation, and centrifugation by the treatment of NaOCl, increased the sensitivity to 75% and 77.9%, respectively, and the specificity to 100% for both techniques. In conclusion, the use of NaOCl in the concentration of AFB in sputum is recommended for use in routine laboratory diagnosis of PTB in developing countries.     

PCR-荧光探针法检测临床痰标本结核分枝杆菌的可靠性研究

目的 评价PCR-荧光探针法快速检测Mtb和非结核分枝杆菌（NTM）的临床应用价值。方法 应用分枝杆菌核酸检测试剂对1015 例痰标本和56株临床分离株进行检测,与Mtb核酸扩增（PCR）荧光（目前临床上认可惟一同类产品）检测结果进行比较。采用SPSS 11.5统计软件进行数据统计处理,采用χ²检验,以P＜0.05为差异有统计学意义。结果 PCR-荧光探针法检测痰标本分枝杆菌灵敏度50.3%（373/741）,特异度98.9%（271/274）;菌阳肺结核标本检测灵敏度97.0%（257/265）,菌阴肺结核标本检测灵敏度24.4%（116/476）;1015份痰标本中检测出11例非结核分枝杆菌（NTM）核酸阳性标本（占1.1%）,经16S rDNA 测序确认,准确率100.0%。随机数字量表法抽取138例标本重复进行第2次检测,符合率100.0%。对56株临床分离株（1株Mtb临床分离株,55株NTM临床分离株）检测,准确率100.0%。对临床需要的226份标本同时与达安公司试剂盒检测结果比较,总体符合率95.1%（215/226）,经统计学分析,两者之间差异无统计学意义（χ²=2.98,P=0.226）。结论 PCR-荧光探针法可快速检测和区分痰标本Mtb与NTM,具有临床推广应用价值。     

结核抗体lgG/lgM检测在肺结核和肺外结核中的诊断价值

目的 探讨异种血清抗体检测技术在结核病诊断中的应用价值。方法 采用IgG/IgM抗体试剂盒分别检测102例结核病患者(包括73例肺结核和29例肺外结核)、223例其他肺部疾病患者和100例对照者结核感染情况,以临床诊断为标准评价该方法的敏感度和特异性,同时分别与痰菌培养及痰涂片平行检验的结果作比较,统计学分析采用χ²检验。结果 结核抗体IgG/IgM检测结核病患者的敏感度为74.51%、特异度为91.64%。结核抗体IgG/IgM检测肺结核和肺外结核的敏感度分别为82.19%、55.17%,肺内和肺外结核的敏感度差异有统计学意义(P＜0.05),结核抗体lgG/IgM检测结核患者阳性检出率明显高于痰培养法和痰涂片法(P<0.05)。102例结核病患者年龄段分组分析,少年组和老年组检出率分别为58.33%、36%,远低于青年组和中年组的96.15%和89.74%。不同年龄组间进行卡方比较分析显示,P＜0.05,差异有统计学意义。425例标本中,共发现8例非结核分枝杆菌,其中6例胞内分枝杆菌, 2例脓肿分枝杆菌,lgG/lgM抗体检测均为阴性。结论 IgG/IgM血清抗体检测肺内、外结核具有快速方便、经济和较高的敏感度,适合用于临床结核筛查。     

荧光探针杂交技术检测临床标本内结核分支杆菌的价值

目的　评价聚合酶链反应(PCR)荧光探针杂交技术(TaqMan技术)检测临床标本中结核分支杆菌的应用价值。方法 应用细菌学方法(涂片镜检和培养)及TaqMan法检测133份结核病患者痰标本,53份非结核呼吸系疾病患者痰标本。结果 细菌学方法检测结核病患者临床标本中结核分支杆菌阳性率为36.1%,TaqMan法阳性率为61.7%,高于细菌学检测法,经统计学处理,两者有显著性差异(P<0.05),用TaqMan法检测临床标本特异性为96.2%。结论 TaqMan技术将PCR扩增、荧光探针杂交及检测一体化,在单一管内完成,具有简便、快速、防污染、敏感性及特异性较高等优点,是结核病辅助诊断的有效方法之一。