• Journal of Microbiology and Biotechnology
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• 제29권9호
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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.

• 대한미생물학회지
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• 제21권3호
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• pp.363-373
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• 1986

We developed a giant colony test system with rapidly growing mycobacteria by stab-culture with a loopful inoculum of cells into Middlebrook 7H10 agar medium containing soluble extracts of the fruits of Gardenia jasminoides(7H10-crocin agar medium) and assessed the significance of the giant colony test with 28 strains of 10 clusters of rapidly growing mycobacteria classified by the simple biological 5-test characters. Of the 10 clusters of mycobacteria tested, some of strains which belonged to cluster No. 1a, 5a and 11a did grow as gravis types, whereas most of other clusters gave mitis or intermedius types in their colonial sizes at 12 days culture. By this test, pathogenic strains of M. fortuitum-chelonei complex which belonged to cluster No. 5a, b, 7a and 8a, b could be divided into gravis, intermedius and mitis colony types and the gravis ones were characterized by bluish-white "mushroom-shaped" colonies with central complexes in the texture, whereas the intermedius gave grayish-white "flower-shaped" colonies with radiated folds, but without any central complexes. The mitis colonies were characterized by grayish-white smooth or smooth mucoid colonies and were common among the clusters in their shapes. The colony of M. chelonei was bluish-white mitis type and was characterized by its hilly rhizoid colony. The gravis colony of cluster No. 1a identified as M. phlei was characterized by yellow "round straw- mat-shaped" or "chrysanthemum-shaped" colony with whole complexes in the texture, and the gravis colonies of the cluster No. 11a gave grayish-white "flower-shaped" colonies with central stamens, radiating trough and fine cup-shaped strands in the texture. The four colony types of pathogenic species of M. fortuitum-chelonei complex on 7H10-crocin agar medium were distinctive from those of other clusters of rapidly growing mycobacteria and these results indicated that the giant colony test, in conjunction with the simple 5-test characters, would be of value in the differentiation of M. fortuitum complex from other clusters of rapidly growing mycobacteria.

• 한국산업보건학회지
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• 제33권3호
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• pp.355-364
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• 2023

Objectives: The objective of the present study was to identify mycobacterial infection in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis. Methods: Sputum samples were collected from 170 retired dusty workers living in Gangwon-do. The mycobacterial culture was grown in 2% Ogawa medium and Mycobacteria Growth Indicator Tube(MGIT). Mycobacterial species were identified using MolecuTech REBA Myco-ID^Ⓡ. Results: Thirty-one(18.2%) out of 170 sputum samples were identified as positive for culture. Among the positive culture samples, eleven(6.5%) were identified as mycobacterial species. The proportion of mycobacteria was M. avium 2.3%(4/170), M. fortuitum complex 1.2%(2/170), M. intracellulare 1.2%(2/170), M. abscessus 0.6%(1/170), M. tuberculosis(MTB) complex 0.6%(1/170), and MYC(NTM except 19 species) 0.6%(1/170). Conclusions: In comparison with previous studies, the incidence rate of tuberculosis(TB) in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis was higher than in close contact with TB patients, workers exposed to silica, and patients with silicosis. And the proportion of non-tuberculosis mycobacteria(NTM) was higher than that of MTB.

• Tuberculosis and Respiratory Diseases
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• 제40권5호
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• pp.483-494
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• 1993

석탄산으로 사멸한 균으로 감작시켜 얻은 토끼 항혈청으로 주요 병원성 mycobacteria의 세포 표면항원간의 항원적 상관관계를 효소결합면역분석법으로 관찰하였다. M, avium-intracellulare(MAI) 항혈청을 이용한 동종 및 이종반응 분석결과를 보면 동종내 항원적 상관관계는 매우 가깝고 M. scrofulaceum(MG)을 포함하면 MAIS군내 종간 항원적 관계도 가까웠다. MAI 혈청이 M. chelonei(MC), fortuitum(MF), nonchromogenicum(MNC), terrae(MTR) 및 triviale(MTV)와는 반응하지 않거나 미약하게 반응하지만 M. kansasii(MK)와 결핵균과는 강하게 반응했다. 그러나 후자의 두균종으로 흡수해도 MAI 혈청의 동종반응은 감소되지 않았다. M. avium(MA) (K40004) 항혈청은 M. intracellulare(MI) 균주를 제외한 다른 균들과는 미약하게 반응했고 항원적 상관관계가 가까운 MI와 MG로 흡수하면 동종반응의 50~89%가 감소했다. MI 혈청의 종내반응이 종간반응보다 물론 더 강하지만 공유항원량의 크기에 따라 달랐다. MI균주 중 N-260D, N-260R, N-260T 및 K41014간의 항원적 상관관계가 N-242D, N257T, N281D 및 N275T와의 관계보다 더 가깝게 나타났다. MNC 항혈청은 MC와 MTV를 제외하고는 강한 교차반응을 보여주었다. 종내 항원적 상관관계 다음으로는 MTR와 MG(K30003)과 가까웠다. NC-3 혈청은 MA, MC 및 MF와 상당한 반응력을 나타내지만 NC-11은 그렇지 않았다. MTR 항혈청은 MI와 강하게 반응하지만 MI로 흡수한다고 해서 그들의 동종반응이 감소하지 않는 것으로 보아 MTR 표면에 공유항원이 많지 않음을 보여주었다. MTR과 MNC, MC 및 MF 사이에도 상당량의 공유항원이 있음이 알려졌다. MTR 가운데 T-8 혈청과는 달리 T-13 항혈청은 MA, MG, MK 및 MTB와 강하게 교차반응하였다. 이상의 실험으로 밝혀진 mycobacteria의 항원적 상관관계가 각종 생물학적 및 생화학적 방법으로 갈라놓은 분류군과 잘 일치하고 있었다.

• 대한임상검사과학회지
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• 제49권4호
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• pp.435-438
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• 2017

비결핵 항상균(Nontuberculous Mycobacteria, NTM) M. avium-intracellular complex (MAC), M. fortuitum, M. chelonae, M. abscessus, M. kansasii 등을 함유한다. 비결핵 항상균은 자연 환경속에 서식하며 다양한 가축등에 감염한다. 그리고 사람한테는 기회감염을 유발하여 사회적 경제적 문제를 야기한다. 본 연구는 면역결핍 사람한테 기회감염을 유발하는 비결핵 항상균이 사람들이 흔히 이용하는 다중이용시설내 존재 유무를 확인하기위해 40개 에어컨 먼지를 채취하여 직접 AFB 염색, 직접 PCR, 간접 AFB 염색, 간접 PCR 등을 실시했다. 그 결과 채취한 샘플의 직접 AFB 염색, 직접 PCR 에서는 인형결핵균(MTB), 비결핵 항상균 모두 발견되지 않았다. 배양된 집락을 이용한 간접 AFB 염색, 간접 PCR 결과 인형결핵균 (MTB)은 모두 음성반응을 나타냈으며, 비결핵 항상균은 40개 샘풀 중 2개(5%)에서 양성반응을 나타냈다. 본 실험결과는 자연 내 비결핵 항상균이 존재한다는 사실을 증명했으며 비결핵 항상균이 기회감염의 원인임을 감안했을 때 다중이용시설의 청결한 위생처리가 중요함을 암시한다. 다만 비결핵 항상균의 종(species) 감별과 기회감염 유발 유무는 좀 더 연구가 필요하다고 사료된다.

• 한국산업보건학회지
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• 제30권1호
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• pp.67-74
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• 2020

Objectives: Previous study has shown that the positive rate of latent tuberculosis infection(LTBI) among former workers in dusty environments was higher than that among high-risk groups of tuberculosis(TB). The objective of the present study was to identify the development of active TB among former workers in dusty environments diagnosed with LTBI. Methods: Between January 2015 and May 2017, 796 former workers in dusty environments who had been subjects of epidemiology research for work-related chronic obstructive pulmonary disease(COPD) had received the QuantiFERON-TB® Gold In-Tube(QFT-GIT) from the Institute of Occupation and Environment(IOE) under the Korea Workers' Compensation and Welfare Service(KCOMWEL). Among them, 437 participants who received a health examination for work-related pneumoconiosis between January 2015 and December 2018 were selected as study subjects. Active TB was defined as a positive result for active PTB and non-tuberculosis mycobacteria infection in the result of the Pneumoconiosis Examination Council's assessment by KCOMWEL. Results: A total of 437 subjects were followed up for 2.1 years. Four of them(4/437, 0.9%) developed active TB during the follow-up period. The attack rate of active TB among subjects who were diagnosed LTBI positive and those who were diagnosed LTBI negative were 0.9%(3/320) and 0.9%(1/115), respectively. Conclusions: Most previous studies reported that the attack rate of the development of active TB in subjects who had been diagnosed LTBI positive was higher than that among subjects who had been diagnosed LTBI negative. To the contrary, the present study found that the rate of developing active TB among former workers in dusty environments diagnosed as LTBI positive was not higher than that in those who were diagnosed LTBI negative.