• The Journal of the Korean Society for Microbiology
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• v.18 no.1
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• pp.47-52
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• 1983

During the last three years, it has become evident that patients with tuberculosis-like diseases due to the Mycobacterium avium-intracellulare complex(referred to M. avium complex; MAC) in Korea are more frequently observed than were assumed earlier. However, the incidence of various serotypes of the MAC isolated from patients with tuberculosis-like diseases has not been clarified. In this study, the serotypes of 16 strains of the MAC isolated from sputa of persons who had radiographic abnormalities of the lungs were determined by bacterial agglutination test with reference sera. The serotypable strains belonged to 7 serotypes, i.e., M. avium 13 were 4 strains(25.0%), M. avium 8 and 14 each 3 strains(18.8%), M. avium 5, 7, 12 and 18 one strain(6.3%), respectively. Two strains(12.5%) were not typable.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.395-401
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• 2009

As the prevalence of tuberculosis declines, the proportion of nontuberculous mycobacterial (NTM) lung disease is increasing in Korea. The combined use of liquid and solid media increases the sensitivity of mycobacterial culture and shortens culture time. Because NTMs are ubiquitous in the environment, NTM lung disease requires strict diagnostic criteria to prevent over-diagnosis of NTM lung disease. Mycobacterium avium complex is the most common pathogen of NTM lung disease in Korea and present in two forms: upper lobe cavitary and nodular bronchiectatic form. Decision of treatment of NTM lung disease depends on the infecting species and overall condition of the patient. Because medical therapy requires the use of multiple drugs over 18 to 24 months, surgery for localized disease may be useful for those species refractory to medical therapy.

• Tuberculosis and Respiratory Diseases
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• v.82 no.1
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• pp.15-26
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• 2019

The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.

• 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.86 no.1
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• pp.47-56
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• 2023

Background: There is a global increase in isolation of nontuberculous mycobacteria (NTM). The aim of the study was to analyze longitudinal trends of NTM identification and pattern of antimicrobial susceptibility testing. Methods: NTM recovery rates, distribution of NTM species identification, and antimicrobial susceptibility pattern of NTM at Pusan National University Yangsan Hospital between January 2016 and December 2020 were retrospectively analyzed. Results: A total of 52,456 specimens from 21,264 patients were submitted for mycobacterial culture, of which 2,521 from 1,410 patients were NTM positive over five years (January 2016 to December 2020). NTM isolation showed an increasing trend from 2016 to 2020 (p<0.001, test for trend) mainly caused by Mycobacterium avium complex. The vast majority of M. avium complex were susceptible to key agents clarithromycin and amikacin. For Mycobacterium kansasii, resistance to rifampin and clarithromycin is rare. Amikacin was the most effective drug against Mycobacterium abscessus subspecies abscessus and Mycobacterium subspecies massiliense. Most of M. subspecies massiliense were susceptible to clarithromycin, while the majority of M. abscessus subspecies abscessus were resistant to clarithromycin (p<0.001). Conclusion: There was an increasing trend of NTM isolation in our hospital. Resistance to key drugs was uncommon for most NTM species except for M. abscessus subspecies abscessus against clarithromycin.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.225-233
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• 1997

A murine leukemia x LM fibroblast hybrid cell line with immune augmenting properties stimulated resistance to Mycobacterium avium complex (MAC) in mouse peritoneal macrophages, and in immune deficient beige mice (C57BL/6/bgj/bgj). The proliferation of MAC in mouse peritoneal macrophages was inhibited by medium conditioned by the growth of the hybrid cells (hybrid cell-CM). Under similar circumstances, media conditioned by the growth of LM cells (LM cell-CM), a mouse fibroblast cell line used as one parent in forming the hybrid cell, was exhibited no inhibitory effect. Treatment of mouse peritoneal macrophages with hybrid cell-CM, but not with LM cell-CM, stimulated the expression of each of four previously described macrophage activation antigens, suggesting that the hybrid cells formed immunomodulators in addition to those formed by LM cells. Furthermore, the morphology of the macrophages following treatment with hybrid cell-CM was clearly distinguishable from that following exposure of the cells to LM cell-CM. The therapeutic effects of hybrid cells on the progression of MAC-infection were indicated by the prolonged survival of MAC-infected immune-deficient beige mice. One hundred percent of treated animals survived more than 60 days, while untreated animals died in approximately 22 days.

• Tuberculosis and Respiratory Diseases
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• v.69 no.4
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• pp.279-283
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• 2010

The global number of Mycobacterium avium complex (MAC) pulmonary infection is increasing. Patients with preexisting lung disease or who are immunodeficient are at the greatest risk for developing MAC infection. Endobronchial lesions with MAC infection are rare in the immunocompetent host. However, there have been an increasing number of reports of an immunocompetent host being afflicted with various manifestations of MAC infection. We report a case of pulmonary and endobronchial MAC infection presenting as an acute pneumonia in a 59-year-old female without preexisting lung disease or immunodeficiency.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.215-228
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• 2002

It is now more than two decades since the AIDS epidemic began with a cluster of Pneumocystis carinii pneumonia (PCP) in a community of homosexual men. Since then, many other infections have been characterized as opportunistic infections secondary to HIV infection. These include, but are not limited to, infections with Toxoplasma gondii, Cytomegalovirus (CMV), Mycobacterium avium complex (MAC), and Cryptococcus neoformans. Over the last two decades, there have been dramatic improvements in diagnosis, prevention and treatment of all these infections. As a result, in North America and Western Furope the rates of opportunistic infections secondary to AIDS have decreased substantially. We will review these common opportunistic infections below.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.333-339
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• 2011

Loop-mediated isothermal amplification (LAMP) was developed to detect Mycobacterium tuberculosis complex (MTC) and non-tuberculous mycobacterium (NTM) genomic DNA in blood samples of Korea native cattle. A set of four primers, two outer and two inner, were designed from M. bovis and M. avium genomic DNA targeting the IS6110 and 16S rRNA gene, respectively. Based on 85 Intradermal Tuberculin Test (ITT) positive blood sample and using conventional PCR and LAMP, the agreement quotient (kappa), which measures agreement beyond chance were 0.93 (conventional PCR) and 0.97 (LAMP), respectively. The detection limit of the LAMP method was $2.0{\times}10^2$ copy/ml M. bovis and M. avium cells, compared to $2.0{\times}10^3$ copy/ml M. bovis and M. avium cells for conventional PCR. These results suggest that the LAMP is a powerful tool for rapid, sensitive, and practical detection of MTC and NTM in blood samples of Korea native cattle.

• 보건세계
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• v.44 no.8 s.492
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• pp.4-6
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• 1997

근래 조형균(Mycobacterium avium complex : MAC)에 의한 항산균증과 일부 약제내성 결핵의 치료제로 알려지고 있는 리파부틴(rifabutin, RBT), 간헐치료제로써 연구가 되고있는 리파펜틴(rifapentine, RPT)에 대하여, 결핵환자와 치료 처방을 결정하는 의사들의 정확한 이해를 돕기 위해 이 약제들에 대한 간단한 소개를 하고자 한다.