• Tuberculosis and Respiratory Diseases
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• v.74 no.1
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• pp.28-31
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• 2013

We present a case of congenital cystic adenomatoid malformation (CCAM) in a 25-year-old male who was presented with chronic cough. Chest radiography revealed an abnormal mass-like shadow in the right lower pulmonary zone. A contrast enhanced computed tomography showed an 11 cm solid, cystic mixed mass on the right lower lobe. A right lower lobectomy was performed by video-assisted thoracoscopic surgery without complications. The gross specimen showed a massive cavitation with multiloculated cysts of varying size, consistent with CCAM, along with noticeable granulomatous inflammation. Non-tuberculosis mycobacteria were isolated from a bronchial wash specimen, and the resected tissue homogenates were positive for Mycobacterium avium-intracellulare complex by polymerase chain reaction.

• Tuberculosis and Respiratory Diseases
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• v.69 no.4
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• pp.250-255
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• 2010

Background: The purpose of this study was to evaluate recently developed real-time polymerase chain reaction (PCR) assay kit to detect Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) in respiratory specimens. Methods: We assessed the positive rate of the real-time PCR assay to detect MTB and NTM in 87 culture-positive specimens (37 sputum, 50 bronchial washing), which were performed real-time PCR by using $Real-Q_{TM}$ MTB&NTM Kit from January 2009 to June 2009, at Gyeongsang University Hospital. To compare the efficacy with the TB-PCR assay, we evaluated 63 culture-positive specimens (19 sputum, 44 bronchial washing) for MTB or NTM, which were performed TB-PCR by using ABSOLUTETM MTB II PCR Kit from March 2008 to August 2008. Results: Among 87 specimens tested using real-time PCR, MTB and NTM were cultured in 58 and 29, respectively. The positive rate of real-time PCR assay to detect MTB was 71% (22/31) and 92.6% (25/27) in AFB stain-negative and stain-positive specimens. For NTM, the positive rate of real-time PCR was 11.1% (2/18) and 72.7% (8/11) in AFB stain-negative and stain-positive specimens. Among 63 specimens performed using TB-PCR, MTB and NTM were cultured in 46 and 17, respectively. The positive rate of TB-PCR was 61.7% (21/34) and 100% (12/12) in AFB stain-negative and stain-positive specimens. TB-PCR was negative in all NTM-cultured 17 specimens. Conclusion: TB/NTM real-time PCR assay is useful to differentiate MTB and NTM in AFB stain-positive respiratory specimens and it is as effective in detecting MTB with TB-PCR.

• Tuberculosis and Respiratory Diseases
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• v.80 no.2
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• pp.153-158
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• 2017

Background: Recently, increased levels of high-mobility group box 1 protein (HMGB1) have been identified in various inflammatory conditions and infections. However, no studies have evaluated the HMGB1 level in nontuberculous mycobacterial (NTM) lung disease, and compared it to mycobacterial lung disease. Methods: A total of 60 patients newly diagnosed with NTM lung disease, 44 culture-positive pulmonary tuberculosis (TB) patients, and 34 healthy controls, were included in this study. The serum HMGB1 concentrations were quantified using HMGB1 enzyme-linked immunosorbent assay kits. Results: Serum HMGB1 level in patients with pulmonary TB or NTM lung disease, was significantly lower than that of the healthy controls. In addition, the serum HMGB1 level in TB patients was significantly lower than patients with NTM lung disease. However, the levels in NTM patient subgroups did not differ according to the causative species, disease progression, and disease phenotype. Conclusion: Although low levels of serum HMGB1 has the potential to be a marker of mycobacterial lung disease, these levels were unable to differentiate disease progression and disease phenotype in NTM lung diseases.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.260-267
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• 2023

We aimed to investigate the proportions of MTB- and NTM-positive tests and the distribution patterns of species isolated by contracted testing agencies in South Korea. Respiratory specimens submitted to contracted testing agencies in South Korea for AFB culture from January 2014 to December 2021 were included (533,713 specimens in total). Trends based on MTB and NTM detection, patient sex and age, culture medium type, and testing year were analyzed. MTB and NTM positive detection increased in the patients. The average ages of MTB- and NTM-positive patients increased in those aged ≥61 years. For solid culture, the MTB detection rate decreased from 5.9% in 2014 to 3.3% in 2018 and increased to 4.7% in 2021; the NTM detection rate increased from 2.1% in 2014 to 3.4% in 2018 and 3.7% in 2021. For liquid culture, the MTB detection rate decreased from 8.3% in 2014 to 5.5% in 2018 and increased to 6.0% in 2021; the NTM detection rate increased from 3.5% in 2014 to 5.5% in 2018 and decreased to 5.3% in 2021. An isolation ratio reversal between MTB and NTM was observed in 2018. In this study, we provide information on mycobacterial isolation rates and species distributions using AFB culture test results from Korea's referral laboratories. Increased MTB- and NTM-isolation rates were observed in individuals aged ≥60 years, indicating the need for regular testing and focused management for them. Expanding liquid culture applications, which show higher positivity rates than solid culture methods, is necessary.

• Tuberculosis and Respiratory Diseases
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• v.59 no.1
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• pp.39-46
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• 2005

Background : Even though it has been suggested that low-colony, scotochromogen nontuberculous mycobacteria (NTM) are usually contaminants and not true pathogens, evidence for this hypothesis has not been provided. This study investigated the colony characteristics, organism identification, and clinical significance of low-colony scotochromogen. Methods : The laboratory cultured 6,898 respiratory clinical specimens for an examination of mycobacteria over a three-month period. A low-colony count was arbitrarily defined as ${\leq}20$ colonies. This study analyzed the recovery rate of the mycobacteria, the number of colonies and their gross characteristics, and their clinical significance. PCR-restriction fragment length polymorphism analysis was carried out to identify the NTM species. NTM pulmonary disease was defined according to the American Thoracic Society. Results : A total of 6,898 respiratory specimens for mycobacterium were cultured. Of these, 263 (3.8%) grew NTM, and 382 (5.5%) grew M. tuberculosis. Of the 263 cultured NTM specimens, 124 (47.1%) were scotochromogens. The smear-positive rate was significantly lower in these scotochromogens (4.8%) than in the non-scotochromogens (23.7%) (p<0.05). The most common isolates were M. gordonae (83/102, 81.4%) in the scotochromogens, and MAC (52/121, 43.0%) in the non-scotochromogens. Even though three out of 113 patients with a low-colony scotochromogen has been diagnosed with NTM pulmonary disease, the isolated scotochromogen was not considered to be the cause of the NTM disease but was just a contaminant. Conclusion : In this study, the most common isolate of a low-colony count scotochromogen was M. gordonae, which appeared to be contaminants and not true pathogens. Greater efforts in the quality control of a mycobacterium laboratory are needed in cases where there is a high recovery rate of low-colony count scotochromogen.

• Tuberculosis and Respiratory Diseases
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• v.78 no.3
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• pp.293-296
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• 2015

Mycobacterium malmoense is a very rare cause of lung disease in South Korea. We reported the first case of lung disease caused by M. malmoense in an immunocompetent patient. The patient was successfully treated with a 14-month course of antibiotics.

• Tuberculosis and Respiratory Diseases
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• v.69 no.1
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• pp.39-42
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• 2010

Mycobacterium massiliense is newly identified rapid-growing nontuberculous mycobacterium, but there are no reports of this mycobacterium species being the cause of human illness. We describe one case of Mycobacterium massiliense infection presenting as antibiotic-resistant acute pneumonia that resulted in surgical treatment.

• Tuberculosis and Respiratory Diseases
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• v.77 no.5
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• pp.227-229
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• 2014

Segniliparus species is a novel genus that is reported to be the new emerging respiratory pathogens. Here, we report a very rare case of S. rugosus pulmonary infection in an immunocompetent patient with non-cystic fibrosis. The organism was identified by 16S rRNA gene sequencing. The patient was successfully treated with antibiotics.

• Tuberculosis and Respiratory Diseases
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• v.75 no.1
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• pp.25-27
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• 2013

Carbohydrate antigen 19-9 (CA 19-9) is a widely-used tumor marker in patients with pancreatic cancer. However, some patients with respiratory disease also exhibit elevated serum CA 19-9 levels. We report a case of normalization of elevated serum CA 19-9 levels after treatment of the nodular bronchiectatic form of Mycobacterium abscessus lung disease. A 40-year-old man visited our hospital because of chronic cough and sputum. A computed tomography scan revealed severe bronchiectasis in the right upper and right middle lobes. Nontuberculous mycobacteria were repeatedly isolated and identified as M. abscessus. The serum CA 19-9 level was elevated to 142.35 U/mL (normal range, <37 U/mL). Surgical resection was performed because of failure of sputum conversion after antibiotic treatment. The serum CA 19-9 level returned to the normal range after surgery. This case suggested that serum CA 19-9 levels could be elevated in patients with the nodular bronchiectatic form of M. abscessus lung disease.

• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.71-79
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• 2015

Background: Recent studies have shown that the nontuberculosis mycobacterium (NTM) recovery rate in clinical cultures has increased within Korea. However, another study conducted by a secondary hospital within Daegu reported different results. Therefore, the purpose of this study is to understand and evaluate the microbiological distribution and clinical features of NTM in Daegu. Methods: A retrospective study was conducted on 11,672 respiratory specimens undergoing acid fast bacilli (AFB) culture from 6,685 subjects who visited Yeungnam University Respiratory Center from January 2012 to December 2013. Results: Of the 11,672 specimens undergoing AFB culture, 1,310 specimens (11.2%) showed positive results. Of these specimens, NTM was recovered from 587 specimens, showing a recovery rate of 44.8%. Identification test for NTM was performed on 191 subjects; the results were as follows: M. avium-intracellulare complex (MAC) 123 (64.4%), M. abscessus 20 (10.5%), M. kansasii 12 (6.3%), and 33 other NTM germ strains. Of the 382 subjects with NTM, 167 were diagnosed with pulmonary NTM disease (43.7%), however virulence differed depending on NTM strain. Multivariate analysis showed that nodular bronchiectasis, the nodules, and finding consistent with cavity under imaging study were statistically significant for triggering pulmonary NTM disease. AFB culture showing MAC and M. abscessus was statistically significant as well. Positive predictive value for NTM polymerase chain reaction (NTM-PCR) was 88.6%. Conclusion: Results for NTM recovery rate within the Daegu area were similar to those for the Seoul metropolitan area. We can assume that NTM infection is increasing in our community, therefore AFB-positive subjects (1) should undergo NTM-PCR, (2) should have their culture results checked for differentiation of mycobacterium tuberculosis complex (MTB) from NTM, and (3) undergo NTM identification test to confirm its type. Administration of treatment with the above results should be helpful in improving the patients' prognosis.