• Biomedical Science Letters
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• v.6 no.1
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• pp.65-72
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• 2000

In order to improve the early diagnosis of Johne's disease in ruminants, duplex polymerase chain reaction system for the detection of the etiologic agent of M. paratuberculosis and for the differentiation of other mycobacterial animal pathogens, such as M. bovis and M. avium, was applied. Genomic DNAs were purified from peripheral blood monocytes or milk macrophages and were used as templates in the duplex PCR. Detection of Mycobacterium spp. in the specimen was carried out by PCR using primer set specific to the mycobacterial 16S rDNA. And then, mycobacterial DNA-positive specimens were further differentiated with duplex PCR system which was composed of primer sets specific to 16S rDNA of M. avium complex and Is900 gene of M. paratuberculosis. The results were re-confirmed by Southern blot hybridization with oligonucleotide specific to the internal sequence of IS900 PCR amplicons. The applicability of this duplex PCR system was evaluated with DNAs extracted from clinical specimens of peripheral blood monocytes and milk macrophages. In summary, the duplex PCR amplification system described in this experiment is promising molecular technique for the early diagnosis of Johne's disease in ruminants.

• The Korean Journal of Medicine
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• v.99 no.4
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• pp.169-179
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• 2024

In recent years, the incidence and prevalence of non-tuberculous mycobacteria lung disease (NTM-LD) has been increasing worldwide. In Korea, Mycobacterium avium complex (MAC) and Mycobacterium abscessus complex account for most common cause of NTM-LD. It is essential to elucidate the pathophysiology of NTM-LD. The pathophysiology of NTM-LD has not been fully understood, however, it can be divided into bacterial and host-side factor. Among the host factor, innate immunity plays an essential role in the initial host immune response against intracellular non-tuberculous mycobacteria (NTM), and adaptive immunity also has a role. However, the role of these immunity in mycobacterial disease has been mainly studied in tuberculosis, but studies on its role in NTM are limited. In this review, I focus on NTM innate and adaptive immunity, the role of macrophages and neutrophils, and host interaction in NTM infection.

• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.234-241
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• 2004

Background : There has been a gradual increase in the number of newly diagnosed cases of Mycobacterium avium complex (MAC) pulmonary disease. However, the optimal therapeutic regimen for the disease has not yet established and there is no report about the treatment outcome of MAC pulmonary disease in Korea. This study examined the effect of clarithromycin-based regimen in patients with pulmonary MAC disease without a HIV infection. Materials and Methods : Fifty-six patients with pulmonary MAC disease were diagnosed according to the American Thoracic Society criteria from January 2000 to December 2003 at this hospital. Of these patients, 15 were treated with clarithromycin, rifampin, and ethambutol for more than 6 months, together with streptomycin initially (first 6 months) in 8 patients. Results : Six months after the treatment, the sputum cultures converted from positive to negative in 8 patients (53%) and the radiological findings improved in 10 (67%). At 12 months 4 patients (44%) achieved sputum negative conversion and 6 patients out of 9 patients (67%) who were treated for more than 12 months showed radiological improvement. Overall, the sputum findings converted to negative in nine patients (60%) who underwent medical treatment. A pulmonary resection was successfully performed in one patient. Only one patient discontinued the treatment due to side effects such as gastrointestinal intolerance and optic neuritis. Conclusion : A combined regimen containing clarithromycin is relatively safe and tolerable even in the elderly outpatients. However, the results of this combined chemotherapy were unsatisfactory and new companion drugs for MAC pulmonary disease are needed. A resection may be considered for localized disease.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.33-44
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• 2003

Background : Mycobacterium avium complex(MAC) is the most common respiratory pathogen in nontuberculous mycobacterial pulmonary disease. This study described the clinical characteristics of the patients with pulmonary disease caused by MAC. Materials and Methods : The clinical characteristics of 24 patients with pulmonary disease caused by the MAC, who fulfilled the 1997 American Thoracic Society diagnostic criteria for nontuberculous mycobacterial pulmonary disease, were retrospectively analyzed. Results : Fourteen patients(58%) were male and the median age at diagnosis was 61 years(range 46-75). Of the 24 patients, 16(67%) had a M. intracellulare infection, 7(29%) had a M. avium infection and one patient was not identified. Coughing (92%) and sputum (88%) were most frequently observed symptoms. The sputum smear for acid-fast bacilli was positive in 17(71%) patients. Fourteen(58%) patients had the upper lobe cavitary form and 10(42%) patients had the nodular bronchiectatic form. In a comparison between the patients with the upper lobe cavitary form and those with the nodular bronchiectatic form, significant differences were found according to sex(male 86% vs. 20%, p=0.003), smoking history(79% vs. 10%, p=0.008), the presence of an underlying disease(64% vs. 20%, p=0.036), the pulmonary function(% forced vital capacity, median 71% vs. 88%, p=0.022; % forced expiratory volume in one second, median 69% vs. 89%, p=0.051) and bilateral disease at chest radiography(29% vs. 90%, p=0.005). The time from the onset of symptoms to diagnosis was longer in those with the nodular bronchiectatic form(median 72 months, range 8-132) than those with the upper lobe cavitary form(median 22 months, range 6-60) Conclusions : MAC pulmonary disease occurs in two distinct populations with two distinct clinical presentations. For a correct diagnosis of MAC pulmonary disease, knowledge of the diverse clinical and radiological findings is essential.

• Tuberculosis and Respiratory Diseases
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• v.74 no.3
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• pp.124-128
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• 2013

Pleural effusion is a rare complication in non-tuberculous mycobacterial infection. We report a case of Mycobacterium intracellulare pleuritis with idiopathic pulmonary fibrosis in a 69-year-old man presenting with dyspnea. Pleural effusion revealed lymphocyte dominant exudate. M. intracellulare was identified using a polymerase chain reaction-restriction fragment length polymorphism method and liquid cultures of pleural effusion and pleural biopsy. After combination therapy for M. intracellulare pulmonary disease, the patient was clinically well at a 1-month follow-up.

• Biomedical Science Letters
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• v.16 no.1
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• pp.10-18
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• 2010

The present study was set to develop comprehensive system for assessing the safety of drinking water using PCR-reverse blot hybridization assay (REBA). The REBA developed in this study can detect waterborne pathogens such as Shigella spp., Salmonella spp., Citrobacter spp., Enterobacter spp., Klebsiella spp., Yersinia spp., Mycobacterium spp., Listeria spp. at the genus level, and Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Yersinia enterocolitica, Y. pseudotuberculosis, Mycobacterium avium complex, M. marinum, Enterococcus faecalis, and Staphylococcus aureus at the species level, and E. coli O157:H7 at the strain level.

• Tuberculosis and Respiratory Diseases
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• v.68 no.4
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• pp.236-239
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• 2010

Hot tub lung is a lung disorder associated with exposure to hot tub water contaminated with Mycobacterium avium complex (MAC). Although its pathogenesis remains unclear, it may be considered hypersensitivity pneumonitis (HP) rather than an infectious disease. We report a case which fulfilled the current diagnostic criteria of hot tub lung. A patient had worked as a cleaner in the public bath for approximately one year and presented with dyspnea for over one month. The computed tomographic finding of bilateral ground glass attenuation and pathologic finding of granulomatous inflammation were consistent with HP. MAC was isolated from bronchoalveolar lavage fluid and hot tub water. After corticosteroid treatment without antimycobacterial medication, the patient improved and there has been no recurrence. The patient has since discontinued working in the public bath.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.49-58
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• 1984

The differential diagnosis of atypical mycobacteriosis caused by atypical mycobacteria (with the exception of Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium leprae) which are widly distributed in soil and water, from pulmonary tuberculosis is possible only when atypical mycobacteria are isolated and identified. In this investigation, attempts were made to isolate atypical mycobacteria from persons registered as tuberculosis patients in the Anyang Health Center in Anyang City, Kyungki province, Korea. Biological and biochemical tests were performed for the atypical mycobacteria isolated from these patients, also retrospective analysis of clinical and X-ray findings of the patients with bacteriologically confirmed atypical mycobacteriosis were done. The results can be summarized as follows: 1. 103 strains of mycobacteria were isolated among 334 sputum samples from patients. 2. Among the isolated mycobacteria, 10 strains (9.7%) were found to be a atypical mycobacteria and 93 strains (90.3%) were tubercle bacilli of human type. 3. On the basis of Runyon's grouping of atypical mycobacteria, there were 3 strains (30.0 %) of scotochromogen and nonphotochromogen respectively, 4 strains (40.0%) of rapid grower, and no photochromogen. 4. By biochemical tests, 3 strains of scotochromogen were identified as Mycobacterium scrofulaceum (2 strains) and Mycobacterium szulgai (1 strain) 3 strains of nonphotochromogen were Mycobacterium avium-complex (2 strains) and Mycobacterium terriae (1 strain), and 4 strains of rapid grower were Mycobacterium fortuitum (3 strains) and Mycobacterium chelonei. 5. In drug sensitivity tests, all 10 strains isolated atypical mycobacteria showed resistance to various concentration of INH and SM and low concentration (10mcg, 40mcg and 50mcg) of EB, TH, and CS, and were sensitive to only high concentration (20mcg and 100mcg) of EB, TH, CS, and RFP. 6. In analysis of clical findings by the patients with bacteriologically confirmed atypical mycobacteriosis, it was found that clinical symptoms of these patients appeared not to be mild than those of patients with pulmonary tuberculosis. The patients with atypical mycobacteriosis had been treated for pulmonary tuberculosis for a long time and they showed no improvement.

• Tuberculosis and Respiratory Diseases
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• v.79 no.2
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• pp.74-84
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• 2016

Nontuberculous mycobacteria (NTM) are emerging pathogens that affect both immunocompromised and immunocompetent patients. The incidence and prevalence of NTM lung disease are increasing worldwide and rapidly becoming a major public health problem. For the diagnosis of NTM lung disease, patients suspected to have NTM lung disease are required to meet all clinical and microbiologic criteria. The development of molecular methods allows the characterization of new species and NTM identification at a subspecies level. Even after the identification of NTM species from respiratory specimens, clinicians should consider the clinical significance of such findings. Besides the limited options, treatment is lengthy and varies by species, and therefore a challenge. Treatment may be complicated by potential toxicity with discouraging outcomes. The decision to start treatment for NTM lung disease is not easy and requires careful individualized analysis of risks and benefits. Clinicians should be alert to those unique aspects of NTM lung disease concerning diagnosis with advanced molecular methods and treatment with limited options. Current recommendations and recent advances for diagnosis and treatment of NTM lung disease are summarized in this article.

• Annals of Clinical Microbiology
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• v.18 no.2
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• pp.37-43
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• 2015

Background: Tuberculosis is globally the most important cause of death from single pathogen. Rapid and accurate identification of mycobacteria is essential for the control of tuberculosis. We evaluated a fluorescence in situ hybridization (FISH) method using peptide nucleic acid (PNA) probes for the differentiation of Mycobacterium tuberculosis complex (MTB) and nontuberculous mycobacteria (NTM) in direct smears of sputum specimens. Methods: The cross-reactivity of MTB- and NTM-specific PNA probes was examined with reference strains of M. tuberculosis ATCC 13950, Mycobacterium kansasii ATCC 12479, Mycobacterium fortuitum ATCC 6841, several clinical isolates of mycobacteria (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium gordonae and Mycobacterium chelonae), and 11 frequently isolated respiratory bacterial species other than mycobacteria. A series of 128 sputa (89 MTB culture positive, 29 NTM culture positive, and 10 under treatment culture negative) with grades of trace to 4+ were used to evaluate the performance of the method. Results: The MTB- and NTM-specific PNA probes showed specific reactions with the reference strains of MTB and M. kansasii and clinical isolates of mycobacteria except M. fortuitum ATCC 6841, and no cross-reactivity with other tested bacteria. The PNA probe-based FISH assay for detection of MTB had a sensitivity and specificity of 100%, respectively. The sensitivity and specificity of the NTM-specific PNA probe was 100%. The smear grades of the PNA FISH test were same as with those of the fluorescence AFB stain in 2+ or higher grade. Conclusion: Detection and differentiation based on PNA FISH is sensitive and accurate for detecting mycobacteria and for differentiating MTB from NTM in clinical sputum smears.