• Tuberculosis and Respiratory Diseases
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• v.72 no.2
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• pp.191-196
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• 2012

While nontuberculous mycobacterium (NTM) infections are recently on the rise, arthritis caused by NTM is hardly reported in Korea. NTM arthritis has no distinctive clinical characteristics from chronic arthritis. Tuberculosis of the joint specifically produces similar clinical and pathologic presentations to NTM arthritis, so it is not easy to distinguish between them. We report a case of Mycobacterium intracellulare in an arthritis patient after trauma and surgical repair of the injury. At the beginning, the patient was diagnosed as tuberculous tenosynovitis through pathology without microbiologic evidence. The final diagnosis was made after subsequent recurrences for several years. The misdiagnosis and delayed diagnosis led to irreversible joint destruction and functional impairment. NTM infection must be included in the differential diagnosis of chronic arthritis at the outset.

• Biomedical Science Letters
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• v.26 no.3
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• pp.170-178
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• 2020

Mycobacterium tuberculosis (MTB) continues to be one of the main causative agents of tuberculosis (TB); moreover, the incidence of nontuberculous mycobacteria (NTM) infections has been rising gradually in both immunocompromised and immunocompetent patients. Precise and rapid detection and identification of MTB and NTM in respiratory specimens are thus important for MTB infection control. Molecular diagnostic methods based on the nucleic acid amplification test (NAAT) are known to be rapid, sensitive, and specific compared to the conventional acid-fast bacilli (AFB) smear and mycobacterial culture methods. In the present study, the clinical performances of three commercial molecular diagnostic assays, namely TB/NTM PCR (Biocore), MolecuTech Real MTB-ID^® (YD Diagnostics), and REBA Myco-ID^® (YD Diagnostics), were evaluated with a total of 92 respiratory specimens (22 AFB smear positives and 67 AFB smear negatives). The sensitivity and specificity of TB/NTM PCR were 100% and 75.81%, respectively. The corresponding values of MolecuTech Real MTB-ID^® and REBA Myco-ID^® were 56.52% and 90.32%, and 56.52% and 82.26%, respectively. TB/NTM PCR showed the highest sensitivity; however, the concordant rate was 10% compared with sequence analysis. Although MolecuTech Real MTB-ID^® showed lower sensitivity, its specificity was the highest among the three methods. REBA Myco-ID^® allowed accurate classification of NTM species; therefore, it was the most specific diagnostic method. Of the three PCR-based methods, MolecuTech Real MTB-ID^® showed the best performance. This method is expected to enable rapid and accurate identification of MTB and NTM.

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.497-509
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• 2006

Until recently, the tuberculin skin test (TST) has been the only tool available for diagnosing a latent TB infection. However, the development of new diagnostic tools, using the Mycobacterium tuberculosis (MTB)-specific early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens, should improve the control of tuberculosis (TB) by allowing a more accurate identification of a latent TB infection (LTBI). Antigen-specific interferon-gamma ($IFN-{\gamma}$) assays have greater specificity in BCG-vaccinated individuals, and as less biased by nontuberculous mycobacterial infections. Many comparative studies have suggested that those assays have a higher specificity than the TST, and the sensitivity of these assays are expected to remarkably improved if more MTB-specific antigens can become available. Nevertheless, the major obstacle to the widespread use of these tests is the limited financial resources. Similar to other diagnostic tests, the predictive value of $IFN-{\gamma}$ assays depends on the prevalence of a MTB infection in the population being tested. Therefore, prospective studies will be meeded to establish the applicability of these new assays at multiple geographic locations among patients of different ethnicities, and to determine if the $IFN-{\gamma}$ responses can indicate those with a high risk of progressing to active TB.

• Clinics in Shoulder and Elbow
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• v.22 no.1
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• pp.46-49
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• 2019

A 73-year-old woman presented with a recurrent cystic mass around her left olecranon. She had a history of 8 steroid injections due to elbow pain beginning 3 years ago and twice had undergone aspiration of olecranon bursitis that developed two months prior to presentation. She had been taking medications for hypertension and diabetes with no pertinent past history. On magnetic resonance imaging (MRI), there were multiple nodules in the olecranon bursa, which were isointense to muscle on T1-weighted images and hyperintense to muscle on T2-weighted images. Our initial diagnosis was synovial chondromatosis. On bursoscopy, masses of gray-white colored nodules were observed in the bursa. Finally, synovial chondromatosis and non-tuberculous mycobacterial infection were concurrently diagnosed. In conclusion, uncalcified synovial chondromatosis and rice bodies can have similar visual and MRI characteristics; therefore, we suggest that clinicians should be aware of the possibility of other infections in cases of this type.

• Tuberculosis and Respiratory Diseases
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• v.72 no.2
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• pp.223-227
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• 2012

Pulmonary siderosis, or Welder's lung disease is an occupational lung disease caused by iron-inhalation. Diagnosis of pulmonary siderosis is based on occupational history of the patient, radiologic findings, and pathologic findings of iron-laden macrophages within lung tissue or broncho-alveolar lavage fluid. We observed a case of a 43 years-old welder diagnosed with pulmonary siderosis via thoracoscopic lung biopsy. Sputum culture along with pathology also identified a non-tuberculotic mycobacterial infection with a sputum culture and the pathologic findings. The patient was treated with anti-tubercular medication and cessation of iron-exposure. And his condition improved within a few months.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.323-330
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• 2009

Nontuberculous mycobacteria (NTM) are a major cause of opportunistic infections in immunocompromised patients, making the reliable and rapid identification of NTM to the species level very important for the treatment of such patients. Therefore, this study evaluated the usefulness of the novel target genes tuf and tmRNA for the identification of NTM to the species level, using a PCRrestriction fragment length polymorphism analysis (PRA). A total of 44 reference strains and 17 clinical isolates of the genus Mycobacterium were used. The 741 bp or 744 bp tuf genes were amplified, restricted with two restriction enzymes (HaeIII/MboI), and sequenced. The tuf gene-PRA patterns were compared with those for the tmRNA (AvaII), hsp65 (HaeIII/HphI), rpoB (MspI/HaeIII), and 16S rRNA (HaeIII) genes. For the reference strains, the tuf gene-PRA yielded 43 HaeIII patterns, of which 35 (81.4%) showed unique patterns on the species level, whereas the tmRNA, hsp65, rpoB, and 16S rRNA-PRAs only showed 10 (23.3%), 32 (74.4%), 19 (44.2%), and 3 (7%) unique patterns after single digestion, respectively. The tuf gene-PRA produced a clear distinction between closely related NTM species, such as M. abscessus (557-84-58) and M. chelonae (477-84-80-58), and M. kansasii (141-136-80-63-58-54-51) and M. gastri (141-136-117-80-58-51). No difference was observed between the tuf-PRA patterns for the reference strains and clinical isolates. Thus, a diagnostic algorithm using a tuf gene-targeting PRA is a promising tool with more advantages than the previously used hsp65, rpoB, and 16S rRNA genes for the identification of NTM to the species level.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.2
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• pp.48-53
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• 2013

Recently, the isolation rate of nontuberculous mycobacteria (NTM) in clinical laboratories and the incidence of NTM infections are on the increase in Korea, but there have been only a few studies that reveal the general aspect of NTM isolation or species distribution. Therefore, this study was performed to examine the species identification by PCR-restriction fragment length polymorphism analysis (PRA, PCR-RFLP), and the clinical significance of mycobacterial cultures. PRA was used during the novel region of the rpoB gene and was developed for rapid and precise identification of mycobacteria to the species level. From January 2012 to April 2012, we examined pre-identified nontuberculous mycobacteria (60 species in 3 hospital of Busan-Kyeongnam area). We confirmed 4 (6.6%) Mycobacterium tuberculosis (MTB) and 56 (93.4%) NTM from 60 pre-identified NTM species by multiplex PCR (MolecuTech $MTB-ID^R$ V3, YD Diagnostics, Korea) and PRA (Myco-ID, YD Diagnostics, Korea). The distribution of 56 NTM species were M. intracellulare type I 15 (26.7%), M. avium 14 (25%), M. abscessus 11 (19.5%), M. kansasii type I 3 (5.4%), M. pulveris 2 (3.6%), M. intracellulare type, M. chelonae, M. kansasii type V, M. gallinarum, M. wolinskyi. Respectively, 1 (1.8%) and 6 (10.7%) species were not identified.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.385-391
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• 2005

Background : The incidence of nontuberculous mycobacterium (NTM) infections in Korea is increasing. This retrospective study was performed to examine the recovery rate of NTM from respiratory specimens as well as the isolated NTM colony characteristics, and to assess the clinical significance of a NTM isolation. Methods : The results of the respiratory specimens requested for an acid-fast bacilli (AFB) examination during 2002 at Asan Medical Center, along with the patients clinical characteristics were analyzed. Results : A total 26,820 respiratory specimens were requested for the acid-fast bacilli (AFB) smear and culture during the study period. The proportion of M. tuberculosis and NTM isolation was 5.7% and 2.2%, respectively. Among the AFB smear and culture positive specimens, 12.2% were found to be NTM. The scotochromogen showing a low colony count < 20, which appeared to be contaminants, were isolated in 31.8% of the 584 NTM isolates. Excluding the low-colony scotochromogens, the M. avium-intracellulare complex was the most common NTM isolates (42.1%), and was also the most common causative organism for NTM pulmonary diseases. 8.4% (23/275) and 17.8% (49/275) of patients with NTM isolates met the American and British Thoracic Society diagnostic criteria for NTM pulmonary disease, respectively. Conclusion : In case of a positive AFB-smear or culture result, the possibility of NTM being a causative organism should always be considered, even in Korea, which has an intermediate incidence of tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.39 no.5
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• pp.425-432
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• 1992

Background: The prevalence of tuberculosis in Korea decreased remarkably for the past 30 years, while for at least the recent 10 years, the frequency of disease attributable to mycobacteria other than tuberculosis (MOTT) began to increase both in actual numbers and in the proportion of the total burden of mycobacterioses. Method: Twenty nine cases, diagnosed as having pulmonary disease due to MOTT on the basis of repeated isolations of the relevant organisms from sputum specimens and chest X-ray findings from Jan. 1982 throught Dec. 1991 at the Chest Clinic of the Korean Institute of Tuberculosis, were reviewed in terms of clinical features and courses. Results: 1) Nineteen cases (66%) were infected with Mycobacterium avium-intracellulare, 5 cases (17%) with M. fortuitum, 4 cases (14%) with M. chelonei, and 1 cases (3%) with M. szulgai. 2) The ratio of male versus female patients was 1.9:1. 3) The peak incidence was in the fifth decade. 4) Eighteen cases (62%) had moderately advanced disease and 11 cases (38%) had far advanced disease on chest P-A film. 5) The common symptoms were cough (59%), sputum (52%), and dyspnea (34%). 6) All cases had a previous history of tuberculosis. 7) Most of the isolates were highly resistant to the major antituberculosis drugs and 48~52% showed a sensitivity to cycloserine, kanamycin or enviomycin. 8) Of 19 cases which were treated and followed-up for over 12 months, 3 cases attained negative conversion on cultures (2 M. fortuitum infections, 1 M. szulgai infection). Sixteen cases failed in attaining negative conversion on cultures. However, their clinical courses were chronic and indolent despite of persistant culture positivity. Conclusion: Treatment of these patients has been difficult because of the frequency of severe underlying conditions and the natural resistance of most of the nontuberculous mycobacteria to the presently available drugs.