• Tuberculosis and Respiratory Diseases
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• v.75 no.4
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• pp.150-156
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• 2013

Background: Thoracoscopic pleural biopsy is often required for rapid and confirmative diagnosis in patients with suspected pleural tuberculosis (PL-TB). However, this method is more invasive and costly than its alternatives. Therefore, we evaluated the clinical utility of the chest computed tomography (CT)-based bronchial aspirate (BA) TB-polymerase chain reaction (PCR) test in such patients. Methods: Bronchoscopic evaluation was performed in 54 patients with presumptive PL-TB through diagnostic thoracentesis but without a positive result of sputum acid-fast bacilli (AFB) smear, pleural fluid AFB smear, or pleural fluid TB-PCR test. Diagnostic yields of BA were evaluated according to the characteristics of parenchymal lesions on chest CT. Results: Chest radiograph and CT revealed parenchymal lesions in 25 (46%) and 40 (74%) of 54 patients, respectively. In cases with an absence of parenchymal lesions on chest CT, the bronchoscopic approach had no diagnostic benefit. BA TB-PCR test was positive in 21 out of 22 (95%) patients with early-positive results. Among BA results from 20 (37%) patients with patchy consolidative CT findings, eight (40%) were AFB smear-positive, 18 (90%) were TB-PCR-positive, and 19 (95%) were culture-positive. Conclusion: The BA TB-PCR test seems to be a satisfactory diagnostic modality in patients with suspected PL-TB and patchy consolidative CT findings. For rapid and confirmative diagnosis in these patients, the bronchoscopic approach with TB-PCR may be preferable to the thoracoscopy.

• Biomedical Science Letters
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• v.22 no.1
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• pp.24-28
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• 2016

Tuberculosis (TB) remains an unsolved community health problem since identification of its causing microorganism called Mycobacterium tuberculosis (MTB) by Robert Koch in 1882. Annually, eight million TB cases are newly reported and 2~3 million patients die from TB. Pulmonary TB is highly infectious and untreated pulmonary TB patients are believed to infect >10 people in a year. The conventional methods for diagnosis of TB are chest X-ray and isolation of the causing microorganisms from patient specimens. Screening of TB is conducted with smeared sputum in slides, and TB is confirmed by identification of MTB in cultured specimens. One of the fatal pitfalls of screening detection for smeared sputum is that it is impossible to distinguish MTB and other acid-fast bacilli (AFB) because they are stained equally with Ziehl-Neelsen (ZN) stain. Culture of MTB is the most reliable method for diagnosis of TB but it takes 4~8 weeks. In this report, we suggest a fast and highly-reliable MTB detection method that distinguishes AFB in sputum samples. Purified DNA from the AFB stained slide samples offered by The Korean Institute of Tuberculosis were used to detect infected MTB in patients. PCR, real-time PCR and reverse blot hybridization assay (REBA) methods were applied to purified DNA. Conclusively, the real-time PCR method was confirmed to produce high sensitivity and we were able to further detect drug-resistant MTB with REBA.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.1004-1007
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• 2014

Culture is the gold standard for diagnosis of tuberculosis, but it takes 6 to 8 weeks to confirm the result. This issue is complemented by the detection method using polymerase chain reaction, which is now widely used in a routine microbiology laboratory. In this study, we evaluated the performance of the Seegene Anyplex TB PCR to assess its diagnostic sensitivity and specificity, and compared its results with the Roche Cobas TaqMan MTB PCR, one of the most widely used assays in the world. Five university hospitals located in the Chungcheong area in South Korea participated in the study. A total of 1,167 respiratory specimens ordered for acid-fast bacilli staining and culture were collected for four months, analyzed via the Seegene Anyplex TB PCR, and its results were compared with the Roche Cobas TaqMan MTB PCR. For detection of Mycobacterium tuberculosis, the diagnostic sensitivity and specificity of the Anyplex TB PCR were 87.5% and 98.2% respectively, whereas those of the Cobas TaqMan were 92.0% and 98.0% respectively (p value > 0.05). For smear-positive specimens, the sensitivity of the Anyplex TB PCR was 95.2%, which was exactly the same as that of the Cobas TaqMan. For smear-negative specimens, the sensitivity of the Anyplex TB PCR was 69.2%, whereas that of the Cobas TaqMan TB PCR was 84.6%. For detection of MTB, the Seegene Anyplex TB PCR showed excellent diagnostic performance, and high sensitivity and specificity, which were comparable to the Roche Cobas TaqMan MTB PCR. In conclusion, the Anyplex TB PCR can be a useful diagnostic tool for the early detection of tuberculosis in clinical laboratories.

• Tuberculosis and Respiratory Diseases
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• v.75 no.6
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• pp.238-243
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• 2013

Background: The aim of our study was to evaluate the "diagnosis changed" rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: "diagnosis maintained", "diagnosis changed" (initially notified as TB, but ultimately diagnosed as non-TB), and "administrative error" (notified as TB due to administrative errors). Results: Excluding 17 patients in the "administrative error" group, the "diagnosis maintained" and "diagnosis changed" groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of "diagnosis changed" were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn's disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a "diagnosis changed" result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high "diagnosis changed" rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the "diagnosis changed" rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of "diagnosis changed" cases is desirable.

• 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.61 no.1
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• pp.54-59
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• 2006

Background: Although there have been several studies regarding the clinical value of an automated TB-PCR study using sputum, bronchial washing, and other body fluid samples for the detection of pulmonary tuberculosis, there are only a few reports on the use of fresh tissue samples. Materials and methods: The acid-fast bacilli stain(AFB), tuberculosis culture, automated TB-PCR study, and histopathology examination were performed in 42 fresh tissue samples. Results: Among the 42 cases, 18 cases were diagnosed with tuberculosis based on the clinical findings. Sixteen of the 18 cases were TB-PCR positive and of these 16 cases, only 2 cases were positive in the AFB stain or culture study. However, all 18 cases showed the histopathology findings of chronic granulomatous inflammation that was compatible with tuberculosis. Based on the clinical findings, the sensitivity, specificity, positive predictability, and negative predictability of the automated TB-PCR study were 88.9%, 100%, 100%, and 92.3% respectively. Conclusion: An automated TB-PCR assay is an important diagnostic tool for diagnosing tuberculosis in fresh tissue samples.

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.235-241
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• 2002

The detection of tubercle bacilli (TB) from sputum smear is one of the fast and inexpensive methods for diagnosis of tuberculosis. For this method. sputum smears are usually flexed by heating and stained by acid-fast staining method, and then examined under an optical microscope. Two Procedures are commonly used fur TB staining. One is hot staining and the other is cold staining method. The Ziehl-Neelsen method which is a hot staining method is widely used in Korea because its stained color is more vivid However, the conventional automated stainer has to fix the sputum smear on a slide manually and the stain is not so vivid because it has not heating function. In an effort to save labor and minimize variations in manual staining Procedure. we developed an automated stainer with heating function. The entire staining process is fully automated. from fixation to final washing and drying. With the automated methods, five slides can be flexed and stained in 21 minutes at consistent high quality We compared the concordance rate between the two methods for 91 sputum samples to validate the stain quality of the developed automated stainer. As the results, the concordant rate between the two methods was 95% and there was no significant difference (p>0.05)

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.44-49
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• 2012

Background: Multidrug-resistant tuberculosis (MDR-TB) is an increasing public health problem and poses a serious threat to global TB control. Fluoroquinolone (FQ) and aminoglycoside (AG) are essential anti-TB drugs for MDR-TB treatment. REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$ (M&D, Wonju, Korea) were evaluated for rapid detection of FQ and kanamycin (KM) resistance in MDR-TB clinical isolates. Methods: M. tuberculosis (n=67) were isolated and cultured from the sputum samples of MDR-TB patients for extracting DNA of the bacilli. Mutations in genes, gyrA and rrs, that have been known to be associated with resistance to FQ and KM were analyzed using both REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$, respectively. The isolates were also utilized for a conventional phenotypic drug susceptibility test (DST) as the gold standard of FQ and KM resistance. The molecular and phenotypic DST results were compared. Results: Sensitivity and specificity of REBA MTB-FQ$^{(R)}$ were 77 and 100%, respectively. Positive predictive value and negative predictive value of the assay were 100 and 95%, respectively, for FQ resistance. Sensitivity, specificity, positive predictive value and negative predictive value of REBA MTB-KM$^{(R)}$ for detecting KM resistance were 66%, 94%, 70%, and 95%, respectively. Conclusion: REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$ evaluated in this study showed excellent specificities as 100 and 94%, respectively. However, sensitivities of the assays were low. It is essential to increase sensitivity of the rapid drug resistance assays for appropriate MDR-TB treatment, suggesting further investigation to detect new or other mutation sites of the associated genes in M. tuberculosis is required.

• 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.65 no.3
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• pp.177-182
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• 2008

Background: Isoniazid (INH, H) is a key drug of the standard first-line regimen for the treatment of tuberculosis (TB), yet some reports have suggested that treatment efficacy was maintained even though INH was omitted from the treatment regimen. Methods: One hundred forty C57BL/6 mice were infected with the H37Rv strain of M. tuberculosis with using a Glas-Col aerosol generation device, and this resulted in depositing about 100 bacilli in the lung. Four weeks after infection, anti-TB treatment was initiated with varying regimens for 4-8 weeks; Group 1: no treatment (control), Group 2 (4HREZ): 4 weeks of INH, rifampicin (R), pyrazinamide (Z) and ethambutol (E), Group 3: 1HREZ/3REZ, Group 4: 4REZ, Group 5: 4HREZ/4HRE, Group 6: 1HREZ/3REZ/4RE, and Group 7: 4REZ/4RE. The lungs and spleens were harvested at several time points until 28 weeks after infection, and the colony-forming unit (CFU) counts were determined. Results: The CFU counts increased steadily after infection in the control group. In the 4-week treatment groups (Group 2-4), even though the culture was negative at treatment completion, the bacilli grew again at the 12-week and 20-week time points after completion of treatment. In the 8-week treatment groups (Groups 5-7), the bacilli did not grow in the lung at 4 weeks after treatment initiation and thereafter. In the spleens of Group 7 in which INH was omitted from the treatment regimen, the culture was negative at 4-weeks after treatment initiation and thereafter. However, in Groups 5 and 6 in which INH was taken continuously or intermittently, the bacilli grew in the spleen at some time points after completion of treatment. Conclusion: TThe exclusion of INH from the standard first-line regimen did not affect the treatment outcome in a murine model of TB in the early stage of disease. Further studies using a murine model of chronic TB are necessary to clarify the role of INH in the standard first-line regimen for treating TB.