• Tuberculosis and Respiratory Diseases
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• v.78 no.3
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• pp.203-209
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• 2015

Background: Induced sputum (IS) has been used to collect airway secretions in subjects who have inadequate sputum production. The aim of this study was to investigate the efficacy of IS for the diagnosis of pulmonary tuberculosis (PTB) in adults unable to expectorate sputum. Methods: Medical records of 39 PTB patients who underwent IS due to absence of spontaneous sputum production between January 2011 and March 2014 at a tertiary hospital in South Korea were reviewed. Results of acid fast bacilli smear, Mycobacterium tuberculosis culture and polymerase chain reaction assay for M. tuberculosis (TB-PCR) of IS specimens from these patients were analyzed. Clinical and high-resolution computed tomography (HRCT) characteristics were also analyzed to find characteristics associated with IS culture positivity. Results: Of the 39 IS specimens from PTB patients, 7 (17.9%) were smear positive and 31 (79.5%) were culture positive. Twenty-four IS specimens were tested for TB-PCR and 13 (54.2%) were positive on TB-PCR. Multivariate analysis showed that younger age (p=0.04) and presence of tree-in-bud appearance on HRCT (p=0.03) were independent predictors of IS culture positivity. Conclusion: IS is useful for the diagnosis of PTB in adults unable to expectorate sputum. Younger age and tree-in-bud appearance on HRCT were associated with IS culture positivity in these patients.

• Tuberculosis and Respiratory Diseases
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• v.81 no.3
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• pp.233-240
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• 2018

Background: Non-conversion of sputum smear and culture prolongs the infectivity of the patient and has been associated with unfavorable outcomes. We aimed to evaluate factors associated with persistent sputum positivity at the end of two months of treatment of new case pulmonary tuberculosis (TB). Methods: Data of 87 human immunodeficiency virus-negative patients with culture-positive drug-susceptible pulmonary TB admitted to local university hospital between September 2015 and September 2016 were reviewed. Factors associated with sputum smear and/or culture positivity at the end of the second month of treatment were analyzed. Results: Twenty-two patients (25.3%) remained smear and/or culture-positive. Male sex, lower body mass index (BMI), unemployment, alcohol abuse, higher number of lobes involved and cavities on chest X-rays, shorter time to detection (TTD) on liquid cultures, higher respiratory sample smear grading and colony count in solid cultures, higher C-reactive protein, erythrocyte sedimentation rate, leukocytosis, thrombocytosis, and anemia were all significantly associated with persistent sputum positivity. However, in the logistic regression analysis only male sex, lower BMI, alcohol abuse, higher radiological involvement, cavitation, higher smear grading, higher colony count in solid cultures and shorter TTD were determined as independent factors associated with persistent sputum positivity at the end of 2 months of treatment. Conclusion: In conclusion, higher sputum smear and culture grading at diagnosis, shorter TTD, higher number of lobes involved, cavitation, male sex, alcohol abuse, and lower BMI were independently associated with persistent sputum positivity. These factors should be sought when distinguishing which patients will remain infectious longer and possibly have worse outcomes.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.152-157
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• 2006

The purpose of this study was to evaluate the usefulness of the automated TB-PCR assay for the detection of Mycobacterium tuberculosis. The 807 cases were analyzed with their TB-PCR, AFB smear and culture in bronchial washing fluids, sputum and body fluids samples. The TB-PCR positive of the bronchial washing fluid, sputum and body fluids were 11.3%, 7.3% and 3.6%, respectively, in cases of AFB smear-negative and culture-negative. The sensitivity values of the bronchial washing fluid, sputum and body fluids were 93.3%, 100% and 50%, respectively, according to the culture result. The sensitivity of body fluids was lower than that of the bronchial washing fluid and sputum. The specificity values of the bronchial washing fluid, sputum and body fluids were 83.3%, 89.0% and 95.7%, respectively, according to the culture result. In conclusion, the automated TB-PCR assay proved to be a useful method for the detection of Mycobacterium tuberculosis in the bronchial washing fluid and sputum. But we think that there is still a need for us to study body fluids further.

• Journal of Microbiology
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• v.40 no.4
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• pp.301-304
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• 2002

Is a multiple number of sputum specimens necessary for the diagnosis of pulmonary tuberculosis? To answer this question, 6844 respiratory specimens obtained from previously untreated patients suspected of having pulmonary tuberculosis between 1998 and 2001 were evaluated retrospectively. All of the specimens were evaluated by acid fast bacilli smear and BACTEC 460 TB culture system. A total of 785 (11%) specimens from 353 patients were positive for Mycobacterium tuberculosis complex. For 76% (270/353) of these patients the organism was detected from sputum specimens collected sequentially for daily basis. Mycobacterium tuberculosis was isolated in the first, second and third samples of the majority (98%,195/199) of patients who had three or more sputum samples sent to the laboratory. Our results indicate that, we could carry out Mycobacterium tuberculosis isolation in the first, second and third sputum samples of the overwhelming majority of the patients and the diagnostic value of four or more sputum specimens submitted to the laboratory was very low (2%). We recommend that, for definitive and cost-effective diagnosis of pulmonary tuberculosis at least three sequential sputum specimens be collected for all patients suspected pulmonary tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.128-137
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• 1996

Background : We can diagnose pulmonary tuberculosis with sputum AFB smear and culture, but sputum AFB smear has low sensitivity and culture needs long period, and they are not available in the patients who can not expectorate effectively. Recently developed, PCR is a fast diagnostic tool in tuberculosis, but false positive and false negative are important problems. So, we studied the diagnostic value of bronchoalveolar lavage fluid AFB smear, culture, PCR through the bronchoscopy. Methods : The 67 pulmonary tuberculosis patients and 43 non-pulmonary tuberculosis patients were analyzed with their sputum specimen AFB smear and culture. Also, bronchoscopy and bronchoalveolar lavage were done, and bronchoalveolar lavage fluid AFB smear, culture and PCR were done. Results: 1) In the cases of pulmonary tuberculosis, the sensitivity of sputum AFB smear and culture were 32.8% and 57.4%, respectively. And the sensitivity of bronchoalveolar lavage fluid AFB smear and culture were 47.8% and 80.6%. respectively. 2) In the cases of pulmonary tuberculosis, the sensitivity and the positive predictive value(for predicting a positive culture) of PCR were 80.6% and 81.5%, respectively. 3) In the cases of sputum AFB smear-negative and culture-negative pulmonary tuberculosis, the sensitivity of bronchoalveolar lavage fluid AFB smear, culture, PCR, and the positive predictive value(for predicting a positive culture) of PCR were 23.1%, 100%, 88.5%, and 82.4%, respectively. 4) The specificity of bronchoalveolar lavage fluid PCR was 77.0%. 5) The median number of days between obtaining a specimen and starting therapy was 5 days for sputum AFB smear, 9 days for bronchoalveolar lavage fluid AFB smear, 26 days for bronchoalveolar lavage fluid PCR, 32 days for sputum culture, 56 days for bronchoalveolar lavage fluid culture. Conclusion : The sensitivity of bronchoalveolar lavage fluid AFB smear and culture are higher than sputum AFB smear and culture. So, the bronchoscopy must be considered for evaluating suspected cases of pulmonary tuberculosis in patients from whom smears of expectorated sputum do not reveal mycobacteria or from whom no sputum can be obtained. Especially, combined with PCR, it is expected that pulmonary tuberculosis can be diagnosed more rapidly and more accurately, so bronchoalveolar lavage fluid APB smear and PCR can be helpful in the early treatment of pulmonary tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.65 no.5
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• pp.379-384
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• 2008

Background: Sputum decontamination with NALC-NaOH (N-acetyl-L-cysteine-sodium hydroxide) is known to better detect Mycobacterium tuberculosis (M. tb) by culture than that with using NaOH, which is widely used in Korean hospitals. In this report, sputum samples collected from pulmonary tuberculosis (TB) patients were treated with either NaOH or NALC-NaOH, and we compared the results of smear and culture positivity to determine whether the NALC-NaOH treatment method improves culture positivity in the sputum samples, and especially for those sputum samples that are smear negative and scanty. Methods: For each decontamination method, 436 sputum samples from pulmonary TB patients in the National Masan Tuberculosis Hospital were collected for this study. Sputum from a patient was collected two times for the first and second day of sampling time, and these samples were employed for the decontamination process by performing the 4% NaOH and NALC-2% NaOH treatment methods, respectively, for detecting M. tb by an AFB (Acid Fast Bacilli) smear and also by culture in solid Ogawa medium. Results: The NaOH and NALC-NaOH treatment methods did not significantly affect the AFB smear positivity of the sputum samples (33.0% vs 39.0%, respectively, p=0.078). However, the culture positive percents of M. tb in the Ogawa medium treated with NALC-NaOH and NaOH were 39.7% and 28.0%, respectively, which was a significantly different (p=0.0003). This difference in culture was more prominent in the sputum samples that were smear negative (the positive percents with NALC-NaOH and NaOH were 15.8% and 7.2%, respectively, p=0.0017) and scanty (NALC-NaOH and NaOH were 60.8% and 42.9%, respectively, p=0.036), but not for a smear that was 1+ or higher (p>0.05). Conclusion: NALC-NaOH treatment is better than NaOH treatment for the detection of M. tb by culture, but not by smear, and especially when the AFB smear is negative and scanty.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.281-285
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• 2009

In this study, we compared the BacT/Alert liquid culture system with Ogawa and $L\ddot{o}wenstein$-Jensen (L-J) media for sputum culture and drug susceptibility test (DST) of Mycobacterium tuberculosis. Rapid liquid culture systems have been widely employed both for primary cultures of M. tuberculosis from clinical specimens and for drug susceptibility test because of its greater sensitivity and faster turn-around time than the conventional egg-based culture methods (Ogawa, $L\ddot{o}wenstein$-Jensen media). Sputum specimens were decontaminated with N-acetyl-L-cysteine (NALC)-4% NaOH and inoculated into the BacT/Alert culture bottles and Ogawa media. 95 from among 135 sputa were smear-positive, 97 (71.9%) were culture-positive by the BacT/Alert culture system, while 89 (65.9%) were positive by Ogawa media. The mean time to culture-positive by the BacT/Alert process system was about 11.3 days, which was significantly shorter than that by Ogawa media (22.4 days). Of 32 M. tuberculosis cultures examined for drug sensitivity, the concordant rate between the two methods (BacT/ Alert liquid culture system, $L\ddot{o}wenstein$-Jensen media) ranged from 87.5% for isoniazid and 90.6% for rifampicin.

• Tuberculosis and Respiratory Diseases
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• v.76 no.4
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• pp.163-168
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• 2014

Background: Mycobacterial identification in active pulmonary tuberculosis (APTB) is confirmative, even though successful rates using self-expectorated sputum are limited. Sputum specimens collected by hypertonic saline nebulization showed higher bacteriologic diagnostic sensitivities over those of self-expectoration, mostly studied in smear-negative or sputum-scarce patients. The efficacy of induced sputum was rarely assessed in real clinical settings. Methods: A prospective randomized case-control study was performed in one hospital. The subjects highly suspicious of APTB were asked to provide 3 pairs of sputum specimens in 3 consecutive days. The first pairs of the specimens were obtained either by self-expectoration (ES) from the next day of the visit or sputum induction with 7% saline nebulization in clinic (SI), and the other specimens were collected in the same way. The samples were tested in microscopy, culture, and polymerase chain reaction (PCR). The outcomes of the bacteriological diagnosis were compared. Results: Seventy six patients were assigned to either ES (38 subjects, median age of 51, 65.8% male) or SI (38 subjects, median age of 55, 52.6% male). APTB was clinically confirmed in 51 patients (70.8%), 27 in ES and 24 in SI. Among the APTB, more adequate specimens were collected from SI (41/65, 63.1%) than ES (34/80, 42.5%) (p=0.01). Bacteriological confirmation was achieved in 14 (58.3%) patients in SI, and 13 (48.1%) in ES (p=0.46). In the same-day bacteriological diagnosis with microscopy and PCR, there were positive results for 9 patients (37.5%) in SI and 7 patients (25.9%) in ES (p=0.37). Conclusion: Sputum induction improves sputum specimen adequacy. It may be useful for the same-day bacteriological diagnosis with microscopic examination and PCR.

• Tuberculosis and Respiratory Diseases
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• v.63 no.5
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• pp.417-422
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• 2007

Background: It is not known with certainty whether patients with persistently positive sputum smear results who have also had negative sputum culture results require prolongation of treatment for tuberculosis in order to avoid an increased risk of eventual relapse. The purpose of the present study was to retrospectively describe the treatment characteristics and evaluate the appropriate duration of treatment in these patients. Methods: Sixty of 69 patients with sputum smear positive and culture negative tests at 5 months after first line anti-tuberculous chemotherapy from 2002 to 2003 were retrospectively analyzed. Exclusion criteria included incomplete treatment or resistance to rifampicin or two additional antibiotics, as determined by a drug susceptibility test (DST). Results: Smear conversion of the study subjects was observed after $8.3{\pm}2.3$ months treatment, and the patients were culture negative after $2.0{\pm}0.8$ months. The relapse rates of the study subjects were 3.8, 10.0, and 25.8% after 1, 2, and 5 years of anti-tuberculosis chemotherapy, respectively. The relapse rates were not significantly affected by a series of risk factors such as age, sex, presence of diabetes, a sputum culture examination after 2 months treatment, previous treatment history, chest radiograph, and duration of the treatment (P>0.05). Conclusion: Regimen change is not required for patients with persistent smear positive but culture negative tests in the fifth month for first line antituberculous treatment. However, a further study will be needed to clarify the high relapse rate in this specific group of patients.

• Tuberculosis and Respiratory Diseases
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• v.80 no.1
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• pp.27-34
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• 2017

Background: A sputum culture is the most reliable indicator of the infectiousness of pulmonary tuberculosis (PTB); however, a spontaneous sputum specimen may not be suitable. The aim of this study was to evaluate the infectious period in patients with non-drug-resistant (DR) PTB receiving adequate standard chemotherapy, using induced sputum (IS) specimens. Methods: We evaluated the duration of infectiousness of PTB using a retrospective cohort design. Results: Among the 35 patients with PTB, 22 were smear-positive. The rates of IS culture positivity from baseline to the sixth week of anti-tuberculosis medication in the smear-positive PTB group were 100%, 100%, 91%, 73%, 36%, and 18%, respectively. For smear-positive PTB cases, the median time of conversion to culture negativity was 35.0 days (range, 28.0-42.0 days). In the smear-negative PTB group (n=13), the weekly rates of positive IS culture were 100%, 77%, 39%, 8%, 0%, and 0%, respectively, and the median time to conversion to culture-negative was 21.0 days (range, 17.5-28.0 days). Conclusion: The infectiousness of PTB, under adequate therapy, may persist longer than previously reported, even in patients with non-DR PTB.