• Tuberculosis and Respiratory Diseases
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• 제74권5호
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• pp.215-221
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• 2013

Background: Nontuberculous mycobacteria (NTM) are considered opportunistic pathogens, and several species of NTM are associated with human diseases that typically involve the pulmonary, skin/soft tissue, or lymphatic systems; such infection may also cause disseminated diseases. Recent studies have reported increasing rates of NTM-induced disease worldwide. Methods: Respiratory samples are being analyzed for acid-fast bacilli (AFB) culture and NTM identification at Dankook University Hospital in Cheonan, Korea, from September 2005 to September 2011. Identification is performed by using polymerase chain reaction-restriction fragment length polymorphism analysis targeting a novel region of the rpoB gene. Results: A total of 25,133 specimens were received for AFB culture, of which 1,014 (4.0%) were NTM-positive. A total of 267 samples from 186 patients were tested for NTM identifications, and 232 samples from 157 patients were positive for NTM species. Among the patients who tested positive for NTM, 65.6% were men and the average age was 63.3 years. Mycobacterium avium complex, the most commonly detected NTM pathogen, was found in 65.9% of the 232 samples. The annual average percentage of NTM isolates from AFB culture-positive specimens was 31.3%: the highest rate was seen in 2011 (44.3%), followed by 2009 (37.4%) and 2010 (37.2%). An upward trend in NTM incidence was found during the study period. Conclusion: The prevalence of pulmonary NTM isolates continues to increase in Cheonan, suggesting that pulmonary NTM disease is becoming increasingly common.

• 대한임상검사과학회지
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• 제46권2호
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• pp.47-53
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• 2014

The purpose of this study was to evaluate the clinical utility of TB/NTM PCR by comparing the results of TB PCR to detect Mycobacterium tuberculous (MTB) and nontuberculous mycobacteria (NTM) from paraffin-embedded tissue specimens. A total of 60 cases were tested using TB PCR and TB/NTM PCR. The MTB and NTM rate of TB/NTM PCR was 84.2% (16/19), 10.5% (2/19) in TB positive of TB PCR. The NTM rate of TB/NTM PCR was 29.3% (12/41) in TB negative of TB PCR. Fourteen different species of NTM were identified, the common isolate was M. gordonae (21.4%), M. avium (14.3%), M. ulcerans (7.1%), M. interjectum (7.1%), M. gilvum (7.1%), M. fortuitum (7.1%), M. mucogenicum (7.1%). The rare species identified were M. farcinogenes (7.1%), M. tokaiense (7.1%). Therefore, TB/NTM PCR is useful to differentiate MTB and NTM from paraffin-embedded tissue specimens and it is more effective in detecting NTM with TB PCR.

• 한국생산제조학회지
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• 제19권1호
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• pp.94-100
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• 2010

Nowadays, several nontraditional machining(NTM) processes are widely used to machine a complex and accurate shape part of hard materials, such as titanium, ceramics, high strength temperature resistant and refractory materials which are difficult to machine and having high strength, hardness, toughness. Machining of these complex shapes in such materials by traditional machining processes are very difficult. The NTM processes is important in the areas of micro- and nano scale machining, where high accuracy and superior surface characteristics are required, which can only be achieved using these NTM processes. So, for effective selection of different NTM processes, careful decision making for a given NTM application is often necessary. An appropriate NTM process for a given material and shape condition is very difficult for the novice engineers. In this paper, an expert system based on an analytic network process(ANP) is suggested for a best selection of NTM process in a NTM application considering an prior interdependency effect among various factors.

• Tuberculosis and Respiratory Diseases
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• 제82권2호
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• pp.94-101
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• 2019

Nontuberculous mycobacteria (NTM) are ubiquitous organisms that are generally found not only in the natural environment but also in the human engineered environment, including water, soil, and dust. These organisms can form biofilms and can be readily aerosolized because they are hydrophobic owing to the presence of the lipid-rich outer membrane. Aerosolization and subsequent inhalation were the major route of NTM lung disease. Water distribution systems and household plumbing are ideal habit for NTM and the main transmission route from natural water to household. NTM have been isolated from drinking water, faucets, pipelines, and water tanks. Studies that used genotyping have shown that NTM isolates from patients are identical to those in the environment, that is, from shower water, showerheads, tap water, and gardening soil. Humans are likely to be exposed to NTM in their homes through simple and daily activities, such as drinking, showering, or gardening. In addition to environmental factors, host factors play an important role in the development of NTM lung disease. The incidence and prevalence of NTM lung disease are increasing worldwide, and this disease is rapidly becoming a major public health problem. NTM lung disease is associated with substantially impaired quality of life, increased morbidity and mortality, and high medical costs. A more comprehensive understanding of the infection source and epidemiology of NTM is essential for the development of new strategies that can prevent and control NTM infection.

• Tuberculosis and Respiratory Diseases
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• 제59권6호
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• pp.606-612
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• 2005

배 경: 최근 국내의 연구에 의하면 객담 항산균 도말검사에 양성을 보인 환자들 중 NTM 분리비율이 약 10%정도로 NTM 폐질환의 중요성이 증가하고 있다. 국립 마산 결핵 병원의 경우 타 병원에 비해 초치료 환자 보다 재치료 및 다제 내성 결핵 환자의 비율이 높고 이런 환자들에 있어서 NTM 폐질환의 여부 및 원인균에 대한 연구가 필요할 것으로 생각된다. 대상 및 방법 : 2002년 8월부터 2003년 7월까지 본원에서 객담 및 기관지 세척액 등 호흡기 검체를 통해 항상균 도말 및 배양검사가 의뢰된 검체에서 NTM이 분리된 환자들을 대상으로 하였다. NTM 폐질환의 진단은 미국흉부학회 진단 기준을 이용하였으며 환자들의 원인균, 임상적 및 방사선적 특징과 NTM 폐질환 발생과 치료성공에 연관된 인자에 대하여 후향적으로 조사하였다. 결 과 : 57명의 환자로부터 의뢰된 100개의 호흡기 검체에서 NTM균이 분리되었다. 미국 흉부학회의 NTM 폐질환 진단 기준에 따라 57명의 환자 중 26명(45.6%)가 NTM 폐질환을 가지고 있었으며 원인균은 M. intracellulare 19명(73.1%), M. abscessus 5명(19.2%), M. fortuitum 1명(3.8%), M. chelonae 1명(3.8%)의 순이었다. 균종에 따른 발병력은 M. intracellulare 67.9%(19/28명), M. abscessus 41.7%(5/12명)로 높았으며 M. fortuitum 14.3%(1/7명), M. chelonae 25%(1/4명)였다. NTM 폐질환 발생과 연관된 인자는 객담 도말양성(odds ratio=6.3, p=0.02), 분리된 균이 MAC 또는 M. abscessus인 경우(odds ratio=6.9, p=0.007)와 관련되어 있었다. NTM 폐질환 환자의 치료성공률은 57.7%(15/26명)이었으며 치료성공과 관련된 인자는 관찰할 수 없었다. 결 론 : 본원의 NTM이 분리된 환자 중 NTM 폐질환 비율은 높았으며 원인균에 있어서 MAC, M. abscessuss순이었다. 그리고 NTM 폐질환 발생과 연관된 인자는 객담 도말양성, 분리된 균이 MAC 또는 M. abscessus인 경우와 관련되어 있었다.

• 대한임상검사과학회지
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• 제52권4호
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• pp.349-355
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• 2020

최근 호흡기 검체에서 결핵균(Mycobacterium tuberculosis complex, MTBC) 검출은 감소하고 비결핵 항산균(nontuberculous mycobacteria, NTM)은 증가하고 있다. 본 연구는 2010년부터 2019년까지 광주 2차 병원에 의뢰된 호흡기검체 132,359예를 대상으로 NTM 검출 증가 대비 NTM 폐질환 환자의 증가와 연령 및 성별 분포를 조사하였다. 그리고 NTM양성환자의 폐결핵 감염 여부를 확인하고자 하였다. 항산균배양 양성률은 2010년 21.9% (1,624/7,403), 2019년 17.4% (1,937/11,161)였다. NTM 분리 비율은 2010년 38.0% (617/1,624)에서 2019년에 72.4% (1,403/1,937)로 증가하였다. NTM 양성환자의 NTM 폐질환 진단률은 평균 27.1%였다. 이 중 현재 폐결핵에 감염된 사례는 2010년 44.4%에서 2019년 23.5%로 감소하고 과거 진단 또는 치료 사례도 15.6%에서 10.6%로 감소하였다. 전체 NTM 폐질환 중 69.0%가 60대 이상이었으며 남자보다 여자 환자가 더 많았다. 향후 고령화와 결핵 관리 정책에 따라 NTM 검출은 증가하는 반면 MTBC는 감소할 것으로 예상되며, 실험실에서는 이 현상에 세심한 주의를 기울이고 지속적으로 검사 결과를 감시해야 할 것이다.

• Journal of Yeungnam Medical Science
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• 제32권2호
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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.

• Tuberculosis and Respiratory Diseases
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• 제79권2호
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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.

• Tuberculosis and Respiratory Diseases
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• 제77권1호
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• pp.1-5
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• 2014

The recovery of nontuberculous mycobacteria (NTM) from respiratory specimens and the number of patients with NTM lung disease have been rapidly increasing in Korea. An early differential diagnosis of NTM lung disease from pulmonary tuberculosis (TB) is important, as the therapeutic regimen differs from that of pulmonary TB, and it is not necessary to track the contacts of patients with NTM lung disease. However, differentiating NTM lung disease from pulmonary TB remains difficult, because the clinical presentations of the two diseases are similar and a definite diagnosis of NTM lung disease based on sputum culture takes time. This review focuses on the changing epidemiology, clinical and radiographic manifestation, and laboratory diagnosis of pulmonary TB and NTM lung disease in Korea.

• Tuberculosis and Respiratory Diseases
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• 제58권3호
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• pp.248-256
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• 2005

목 적 : NTM질환이 과거에는 공중 건강에 치명적인 것으로 생각하지 않았다. 최근에 NTM이 높은 빈도로 발견되고 있고, 분리균의 임상적인 중요성도 커지고 있다. 본 연구는 부산의 한 삼차 의료기관에서 의뢰한 임상 검체에서 분리된 NTM의 균종 분포와 폐질환을 일으킨 균주의 임상적 특징에 대해 알아보고자 하였다. 대상 및 방법 : 2003년 3월부터 2003년 12월까지 10개월간 진단검사의학과 임상미생물검사실에 항산균 도말 및 배양검사가 의뢰되어 도말 및 배양 양성을 보인 검체를 DNA-probe hybridization을 이용한 DNA chip을 통해 항산균종(Genotyping)을 확인했다. 비결핵항산균 동정이 이루어진 환자를 대상으로 미국흉부학회(ATS)의 진단 기준에 합당한 환자를 NTM 폐질환군으로 정의하였으며, 이 환자들에게 발견된 균종, 나이, 성별, 기저 질환, 흉부 방사선 소견 등을 조사하였다. 결 과 : 항산균 배양(AFB culture)양성 균주 중 99개 검체에서 NTM동정이 의뢰되었고, 이중 23명의 환자에게서 24개 균주(24.2%)의 NTM이 확인되었다. 확인된 검체는 객담에서 19균주, 기관지세척액에서 4균주, 대장액(colon fluid)에서 1균주가 분리되었다. 24개의 검체에서 MAC이 13균주(54.2%)로 가장 많은 비율을 차지 하였고 M. szulgai가 3균주(12.5%), M. kansasii, M. malmoense가 2균주(8.3%), M. abscessus, M. chelonae, M. scrofulaceum도 각각 1균주(4%)씩 분리되었고 1균주는 분류되지 않은 균주였다. 23명의 환자 중 ATS 폐감염 기준에 부합되는 NTM 감염 환자는 총 11명(45.8%)이었으며, 평균 연령은 61세(38-76세)였다. MAC이 6균주(54.5%)로 가장 많고, M. szugai가 2균주(18.2%), M. abscessus, M. kansasii 등이 1균주(9.1%)였다. MAC이 분리된 환자 13명 중 6명(46.1%) 그리고 M. szulgai가 분리된 환자 3명 중 2명(67%), M. chelonea complex가 2명 중 1명(50%)이 임상적 의의가 있는 NTM 폐질환을 가지고 있었다. 환자들의 기저질환은 악성종양이 6명이며 그 중 5명이 폐암 환자였고 폐결핵의 과거력을 가진 사람은 4명 이었다. 흉부 방사선 촬영으로 분류한 결과 파괴성 폐형태(destructed lung pattern)은 3명, 공동성 종괴 형태(cavitary mass pattern)은 3명, 결절형(nodular pattern)이 2명(흉수동반 포함), 망상결절형(reticulonodular pattern), 경화형(consolidation pattern), 기관지확장형(bronchiectasis pattern)이 각각 1명 관찰되었다. 결 론 : 부산소재 한 대학병원에서도 다양한 형태의 NTM 폐질환이 발생하였고, 균종의 빈도는 MAC이 가장 많은 비율을 차지 하였고 M. szulgai, M. kansasii, M. malmoense M. abscessus, M. chelonae, M. scrofulaceum순이었다.