四县（区）结核病防治机构固体培养能力建设调查

目的 评估固体培养试验在我国县（区）级结核病防治机构（简称“结防机构”）应用的可行性。方法 选取黑龙江省北林区和兰西县及湖南省湘潭县和岳阳县4个县（区）级结核病实验室,自2010年5月至2011年2月连续纳入2059例具有肺结核可疑症状的初诊患者,收集患者痰标本完成分枝杆菌涂片镜检和固体培养试验,按月统计涂阳培阴率和污染率。按照培养试验室内质量控制要求,初诊患者涂阳培阴率要求低于10%,污染率要求控制在2%～5%。 结果 （1）全部患者涂片和培养阳性率分别为18.3%（376/2059）和26.6%（547/2059）,差异有统计学意义（χ²=129.2,P<0.01）。（2）北林区涂阳培阴率为16.5%(23/139),超过正常要求低于10%的水平。湘潭县和岳阳县培养污染率分别为5.6%(157/2800) 和9.7%(252/2590),超过正常要求低于5%的水平。其余县（区）涂阳培阴率和培养污染率均处于正常范围。结论4个县（区）级实验室初步具备了分枝杆菌固体培养试验能力。     

肺结核病患者痰涂片及痰培养检测结果分析

目的 分析肺结核患者痰涂片及痰分离培养抗酸杆菌检验情况,为确诊和控制结核病提供科学诊断依据。方法 2008-06/2011-05四川省双流县结核病门诊就诊的可疑肺结核（可疑者）2 418例及化疗期间肺结核患者（治疗者）649例,总计3 067例,分别对每例就诊者进行痰涂片和培养检测。结果 3 067例就诊者中查出抗酸杆菌阳性777例,总阳性率为25.33%（777/3067）,其中痰涂片阳性（涂阳）524例,痰培养阳性（培阳）651例,阳性率分别为17.09%和21.23%。2 418例可疑者涂阳383例,培阳619例,阳性率分别为15.84%（383/2418）和25.60%（619/2418）,培阳高于涂阳,差异有统计学意义（P〈0.01）。649例肺结核治疗者涂阳141例,培阳32例,阳性率分别21.73%（141/649）和4.93%（32/649）,涂阳高于培阳,差异有统计学意义（P〈0.01）。结论 可疑肺结核者痰培阳高于涂阳,而肺结核治疗者涂阳高于培阳,痰涂片抗酸杆菌检测特异性高而敏感性低,分离培养敏感性、特异性均较高。     

关于结核菌检查中涂阳培阴现象的探讨

为探讨本地区涂阳培阴(SPCN)菌发生频度等问题,本文总结了我院1988～1989年839份同时做涂片和培养对照观察的痰标本实验结果,报告如下。材料与方法一、全部痰标本取自我院住院肺结核病人,每份痰标本同时做涂片镜检和培养。 1.涂片法收集痰液于一广口瓶内,加等量10％氨     

Xpert Mtb/RIF检测技术在结核病诊断中的应用评价

目的 评估Xpert Mtb/RIF检测技术快速诊断肺结核及利福平耐药的可靠性.方法 在4个县（区）级结核病防治机构（湘潭县、岳阳县、绥化市北林区和兰西县）,门诊医生连续纳入2142例初诊肺结核可疑患者,每例患者留取3份痰标本,实验室工作人员对每份标本同时进行涂片镜检、固体培养和Xpert Mtb/RIF（利福平耐药实时荧光定量核酸扩增检测技术）检测,临床医生2个月末对患者完成随访.省级参比实验室对555例培养阳性患者完成比例法利福平药敏试验,国家参比实验室对传统药敏试验和Xpert Mtb/RIF检测结果不一致菌株进行rpoB耐药基因核心区间测序.以随访后临床诊断结果为金标准,比较涂片镜检、固体培养和Xpert Mtb/RIF检测结核分枝杆菌的敏感度.以传统药敏试验结果为金标准,分析Xpert Mtb/RIF检测利福平耐药的效能.结果 以临床诊断结果为金标准,涂片镜检、固体培养和Xpert Mtb/RIF检测结核分枝杆菌的敏感度分别为25.68％（284/1106）、51.44％（555/1079）和58.82％（650/1105）,Xpert Mtb/RIF检测敏感度高于涂片镜检（x2=360.10,P＜0.05）和固体培养试验（x2=50.13,P＜0.05）.以传统药敏试验结果为金标准,XpertMtb/RIF检测利福平耐药的敏感度和特异度分别为87.10％（27/31）和97.95％（477/487）.结论 Xpert Mtb/RIF检测操作简单,检测敏感度高于涂片镜检和固体培养,同时可以诊断患者是否对利福平耐药,在我国县（区）级实验室具有非常好的应用前景.     

219例痰标本涂阳培阴情况(摘要)

由于病人长期应用抗结核药物,能影响结核杆菌在培养基上生长的速度和活力,从而影响到结核杆菌的培养阳性率。本文对1986～1987年间门诊和住院219例肺结核病人的痰标本,同时做了涂片镜检和培养(方法按全国统一规定的操作规程)。结果涂阳培阴(SPCN)菌为5.9％,与天津的     

不同温度下应用荧光染色法检测抗酸杆菌的研究

荧光染色法检测抗酸杆菌是结核病实验室诊断的重要方法之一，我们对此进行了改进。本研究应用双盲法比较３７℃和室温下荧光染色法对抗酸杆菌检出率的影响，选取１１７例住院结核病人痰标本涂片染色镜检并培养，结果发现３７℃染色时涂片阳性率为６２．４％，而室温染阳性率分别为３９．３％，３７℃染色明显提高了是性检出率，实验同时发现培养阳性率仅为１６．２％，明显低于涂片镜检，特别是３７℃染色镜检的阳性率，涂（＋）培（     

下呼吸道痰标本镜检在医院获得性肺炎诊治中的作用

目的探讨下呼吸道痰标本镜检在医院获得性肺炎（HAP）早期诊治中的临床价值。方法对ICU内HAP疑诊61例患者经人工气道抽取下呼吸道痰标本分别进行痰涂片镜检和培养，以痰涂片结果阳性为HAP初诊，最终临床诊断为HAP确诊，比较初诊的准确性与痰涂片、培养结果的一致性。结果61例患者共送检93例次HAP疑诊患者合格痰标本，HAP初诊49例次，最终临床确诊30例次；HAP初诊敏感度90％，阴性预测值93％；HAP确诊时痰培养结果与涂片结果完全符合率60％，部分符合率33％。结论合格的下呼吸道痰标本镜检能够协助HAP的早期诊断。     

排菌肺结核病人化学疗法前后痰涂片与培养检查结果的观察研究

本文对３２３例完成全面监督下短程化疗的肺结核病人治疗前后痰涂片和培养结果进行了分析。治疗前首次２痰标本检查，涂片和培养阳性率分别为８０．１％和９３％，第二个标本检查涂片与２阳性率分别增加了１３．６％和２．８％。即两个痰标本的阳性检出率要当于一次培养的阳性率。痰涂阳培阴病例在化疗第一个月为１８．４％，第二个月最高为２０．２％，持至第产个月仍有２．９％的病例。化疗后第二个月痰培养的阴转速度比涂片高出约     

中国区县级结核病防治机构结核分枝杆菌涂片和培养结果多中心比对分析研究

目的 分析我国区县级结核病防治机构（简称“结防机构”）就诊患者痰涂片和培养结果之间的关系。方法 选取全国耐药性基线调查期间通过分层整群抽样方法随机抽取的18个区县级结防机构,自2007年4-12月连续纳入的1230例初治和复治涂阳患者痰标本,共计3550份,采取“三涂两培”的方法（即3份痰标本均为阳性,选取阳性级别高的2份痰标本进行培养;3份痰标本2份阳性,选取2份阳性痰标本进行培养;3份痰标本1份阳性,选取阳性标本和1份质量好的阴性标本进行培养）,完成涂片和培养试验,计算患者即时痰、夜间痰和晨痰不同痰标本的涂片阳性率和培养阳性率,分析涂片和培养结果的相关关系。 结果 结核病患者即时痰、夜间痰和晨痰涂片阳性率分别为78.8%（917/1164）、87.0%（1070/1230）和90.0%（1040/1156）,即时痰、夜间痰和晨痰培养阳性率分别为96.9%（504/520）、97.1%（881/907）和97.8%（709/725）,对2147份痰标本涂片结果阳性级别和培养结果阳性级别进行趋势χ²检验,发现两者存在一定的线性趋势相关关系 (χ²=206.2,P<0.01)。 结论 涂片结果在一定程度上可为培养结果提供依据,涂片阳性级别越高,培养阳性级别也越高。     

关于抗酸杆菌涂阳培阴现象的探讨(附22例分析)

本文在对22例涂阳培阴病例的分析中发现,我院在痰菌检出中出现涂阳培阴率为4.4％;涂阳培阴现象多出现于化疗之后,且与利福平的应用有关。涂阳培阴多见于厚壁空洞病例,本文占59.1％。耐多种药物易形成涂阳培阴,多数病例是化疗中痰菌阴转的一个过程,预后良好。极少数病例涂阳培阴与涂阴培阴交替出现,提示病情恶化。     

BACTEC MGIT 960和BACT/ALERT 3D系统快速培养和鉴定痰中抗酸杆菌

目的对抗酸染色阳性痰行分枝杆菌培养和鉴定。方法采用萋一尼氏抗酸染色法对临床诊断肺结核患者的晨痰涂片直接镜检,抗酸染色阳性痰经BACTEC960和BACT/ALERT3D系统进行分枝杆菌培养,分别经对硝基苯甲酸（PNB）和噻吩-2-羧基肼（TCH）培养基生长试验行分枝杆菌菌群和结核分枝杆菌复合群菌种鉴定。结果抗酸染色阳性痰标本的分枝杆菌培养阳性率100％,大多数为结核分枝杆菌（9／10）,少数为非结核分枝杆菌（1／10）,最快6天即可报告分枝杆菌阳性培养。结论BACTEC 960和BACT／ALERT3D系统具有快速培养分枝杆菌作用,抗酸染色阳性痰有必要行分枝杆菌培养和鉴定,有利于肺结核与非结核分枝杆菌病的鉴别诊断、结核分枝杆菌菌种鉴定和抗结核药物敏感性试验。     

Evaluation of mycobacteria growth indicator tube (MGIT), an automated culture system for detection of mycobacteria from clinical specimens

We compared the Mycobacteria Growth Indicator Tube 960 (MGIT 960) and Ogawa medium (OM) for the detection of mycobacteria (acid fast bacteria: AFB) using 882 sputum specimens. Overall, 120 strains of AFB were isolated by the MGIT 960 system and 99 strains of AFB were isolated by using OM. As far as Mycobacterium tuberculosis is concerned, 88 and 71 isolates were achieved by the MGIT 960 and OM respectively. A total of 28 isolates (18 isolates of M. tuberculosis and 10 isolates of nontuberculous mycobacteria: NTM) were detected by the MGIT 960 only whereas only 2 isolates (1 M. tuberculosis and 1 NTM) were detected by OM only. Of these sputum specimens, 72 were smear positive for AFB. The rates of smear negative but culture positive specimens were 8.0% (65 out of 809) for the MGIT 960 system and 6.2% (50 out of 809) for OM. The contamination rate for MGIT 960 was only 1.2%. The average time required for detection of M. tuberculosis was 14.1 days by the MGIT 960 system and 24.6 days by OM. For the NTM, the average detection time were 8.3 days for the MGIT 960 system and 22.8 days for OM. These results indicate that the MGIT 960 system allows detection of mycobacteria significantly faster than OM.     

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.     

New recommendations for duration of respiratory isolation based on time to detect Mycobacterium tuberculosis in liquid culture.

It was hypothesised that the time to detect Mycobacterium tuberculosis in liquid culture of sputum from patients with pulmonary tuberculosis may be a better indicator for the duration of respiratory isolation than sputum smear status. Pre-treatment and during-treatment sputum acid-fast bacilli (AFB) smear and culture results were reviewed in 284 patients with pulmonary tuberculosis. The time to detect M. tuberculosis in liquid culture (TTD-TB) was the number of days from inoculation of the Mycobacterial Growth Indicator Tube to culture detection and visualisation of AFB. The median (interquartile range) TTD-TB for smear group 0 (no bacilli seen) was 14 (12-20) days. This value was used as the standard at which release from isolation could be permitted. In smear group 4 (>9 AFB per high-power field (hpf) in sputum specimens before treatment) patients, the TTD-TB exceeded 14 days after a median of 25 days of treatment. The current authors recommend that patients in smear groups 1 and 2 (1-9 AFB per 100 hpf and 1-9 AFB per 10 hpf in sputum specimens before treatment, respectively) receive treatment in respiratory isolation for 7 days, provided the risk of drug resistance is low. Smear group 3 (1-9 AFB per hpf) and 4 patients should receive treatment in respiratory isolation for 14 and 25 days, respectively. These criteria would have reduced the duration of respiratory isolation by 1,516 days in the 143 study participants with sputum smear-positive pulmonary tuberculosis. Provided clinical and radiographical criteria are satisfactory, use of the time to detect Mycobacterium tuberculosis in liquid culture could enable the duration of respiratory isolation to be predicted from the pre-treatment sputum smear grade. The recommendations enable isolation to end well before sputum becomes smear negative, with considerable benefits to patients and healthcare providers.     

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.     

Viability of stored sputum specimens for smear microscopy and culture.

A laboratory study was performed to determine how long sputum specimens from smear-positive tuberculosis patients can be stored at room temperature or in the refrigerator and retain a positive acid-fast bacilli (AFB) smear or a positive mycobacterial culture. Sputum samples from 30 patients were examined up to 4 weeks and samples from 13 patients examined up to 8 weeks. Provided samples had not dried out, all sputum smears remained AFB positive up to 4 and 8 weeks. In both patient groups, at 4 weeks 37-39% of specimens at room temperature grew mycobacteria compared with 54-67% of specimens stored in the refrigerator. These results have implications for tuberculosis programme policy.     

Bronchoscopic aspiration and bronchoalveolar lavage in the diagnosis of sputum smear-negative pulmonary tuberculosis

The ability to make a definitive diagnosis in sputum smear-negative pulmonary tuberculosis by bronchoscopic aspiration, bronchoalveolar lavage (BAL), and examination of postbronchoscopy sputum were compared. Thirty-four patients with lesions on chest x-rays suspected of being pulmonary tuberculosis were entered into the study. The diagnosis of pulmonary tuberculosis was subsequently confirmed in 28 patients and the method of arriving at the final diagnosis was analyzed. A positive acid-fast bacilli (AFB) smear result was obtained in 4/28 (14%) of cases by a combination of bronchoscopic techniques and postbronchoscopy sputum examination. Prebronchoscopy sputum culture was positive in 12/28 (43%). Combined with bronchoscopy specimens, a positive AFB culture result was obtained in 26/28 (93%). Sputum examination, bronchoscopic aspiration, and BAL are complementary techniques and together they give a high yield of definitive diagnosis of pulmonary tuberculosis.     

Bronchoscopic aspiration and bronchoalveolar lavage in the diagnosis of sputum smear-negative pulmonary tuberculosis

The ability to make a definitive diagnosis in sputum smear-negative pulmonary tuberculosis by bronchoscopic aspiration, bronchoalveolar lavage (BAL), and examination of postbronchoscopy sputum were compared. Thirty-four patients with lesions on chest x-rays suspected of being pulmonary tuberculosis were entered into the study. The diagnosis of pulmonary tuberculosis was subsequently confirmed in 28 patients and the method of arriving at the final diagnosis was analyzed. A positive acid-fast bacilli (AFB) smear result was obtained in 4/28 (14%) of cases by a combination of bronchoscopic techniques and postbronchoscopy sputum examination. Prebronchoscopy sputum culture was positive in 12/28 (43%). Combined with bronchoscopy specimens, a positive AFB culture result was obtained in 26/28 (93%). Sputum examination, bronchoscopic aspiration, and BAL are complementary techniques and together they give a high yield of definitive diagnosis of pulmonary tuberculosis.     

The role of bronchoscopy in the diagnosis of pulmonary tuberculosis in patients at risk for HIV infection.

The present study was undertaken to clarify the role of bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) in the diagnosis of pulmonary tuberculosis in patients at risk for human immunodeficiency virus (HIV) infection. We retrospectively identified 31 patients at risk for HIV who proved to have Mycobacterium tuberculosis on culture of at least one pulmonary specimen. All had pulmonary symptoms but initial sputum smears negative for acid-fast bacilli (AFB). All underwent fiberoptic bronchoscopy (FOB), including BAL and TBB; postbronchoscopy sputum was also collected in 19 patients. A specimen was considered to yield an immediate diagnosis when positive for AFB either on smear or histologic study; granulomas alone were considered positive when no other causes were identified. Overall, an immediate diagnosis was made by bronchoscopic specimens in 15 (48 percent) of 31 cases. TBB was the sole positive specimen in seven patients (23 percent). For comparison, similar specimens from 40 patients in whom M avium complex (MAC) grew on culture were also evaluated. An immediate identification of AFB was made in only four patients (10 percent). We conclude that the finding of AFB on staining of any pulmonary specimen is highly suggestive of tuberculosis, rather than MAC, and warrants institution of antituberculosis therapy. Of all bronchoscopic specimens, TBB provides the highest yield for an immediate diagnosis of tuberculosis.