• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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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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• v.71 no.4
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• pp.249-253
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• 2011

Background: Mycobacterial infection is a problem throughout the world along with the increase of immunocompromised patients. For this reason, there have been many methods for faster and more accurate diagnosis. In this study, we evaluated several laboratory methods for mycobacterial infection. Methods: From January to December 2009, 635 specimens were cultured with mycobacteria growth indicator tube (MGIT) and Ogawa media. Polymerase chain reaction (PCR) was performed with the AdvanSure tuberculosis (TB)/non-tuberculosis mycobacterium (NTM) real-time PCR Kit (LG Life Sciences, Seoul, Korea). The 69 samples showing positive culture results were identified with the AdvanSure Mycobacteria Genotyping Chip Kit (LG Life Science, Seoul, Korea). Results: Sixty-nine (10.9%) out of 635 samples showed positive results for mycobacterial culture. Among the 635 samples, 64 were positive in MGIT, but only 42 were positive in Ogawa media. Of the 635 samples, 607 (95.6%) showed the same results between MGIT and Ogawa and the results of 579 (95.4%) were also consistent with the TB/NTM real-time PCR results. However, in the case of NTM, only one (1/24, 4.2%) was positive in PCR. In the Mycobacteria genotyping chip analysis, the most frequently identified NTM species in descending order were M. avium, M. intracellulare, M. chelonae and M. abscessus. Conclusion: Culturing with a combination of MGIT and Ogawa is recommended to increase the recovery rate of mycobacteria. Although PCR missed a reasonable number of NTM, it is faster and usually gives results that concur with those from the culture. The appropriate combination of diagnostic methods with clinical correlation are necessary.

• 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.74 no.6
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• pp.251-255
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• 2013

Tuberculosis (TB) is one of the largest health problems in the world today. And the incidence of nontuberculous mycobacteria (NTM) lung disease appears to be increasing worldwide. Recently, an automated, nucleic acid amplification assay for the rapid detection of both Mycobacterium tuberculosis and rifampin resistance was developed (Xpert MTB/RIF). And fixed-dose combinations of anti-TB drugs and linezolid have been introduced in the treatment of TB. And new NTM species, named Mycobacterium massiliense, which is very closely related to Mycobacterium abscessus was reported. In this review, these recent advances in the diagnosis and treatment of TB and clinical characteristics of M. massiliense lung disease are discussed.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.1
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• pp.1-5
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• 2015

The nontuberculous mycobacteria (NTM) have been found in different environmental sources. They tend to colonize different body surfaces and secretions. The purpose of this study is to evaluate the presence of NTM in the theater environment. Fifty of Theater environment sample were examined using acid-fast stain, Lowenstein-Jensen medium culture, PCR and DNA-Sequencing. 4 of 50 samples were detected as NFB in AFB stain, L-J medium culture, PCR. and then, All of 4 NTM stains identified as Mycobacterium fortitum type in DNA-sequencing result.

• Journal of Yeungnam Medical Science
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• v.29 no.2
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• pp.83-88
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• 2012

Background: This study was conducted to evaluate the usefulness of the BACTEC MGIT (Mycobacterium Growth Indicator Tube) 960 system for mycobacteria culture and immunochromatographic assay to identify Mycobacterium tuberculosis (MTB) in positive MGIT culture. Methods: Mycobacteria-culture-positive cases were retrospectively analyzed from December 2010 to July 2011. The detection rates and the recovery times of the mycobacteria between the Ogawa media and the MGIT were compared. An immunochromatographic assay (ICA) (SD BIO-LINE) was also performed in the positive MGIT culture for identification, and the results were compared with those of the Ogawa media in the Korea National Tuberculosis Association. Results: Among the 261 patients (M:F, 168:93; mean age, $61.6{\pm}17.16$ yrs), 450 specimens (sputa, 365; bronchial washing, 61; and pleural effusion, 24) were found positive with mycobacteria. Mycobacteria were grown both on the MGIT and Ogawa media in 310 cases (68.9%); only on the MGIT in 115 cases (22.6%); and only on the Ogawa media in 25 cases (5.5%) (p<0.05). The recovery time was $28.2{\pm}8.9$ days in the Ogawa media and $11.1{\pm}5.8$ days in the MGIT (p<0.05). Among the 127 cases from the positive MGIT culture, all 92 cases that were confirmed as MTB cases bythe Korea National Tuberculosis Association were identified as MTB by ICA, with 100% sensitivity. Conclusion: MGIT increases the detection rate and shortens the recovery time of mycobacteria in clinical respiratory specimens, and the TB Ag MPT64 kit using ICA is useful in identifying MTB in a positive MGIT culture.

• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.25-34
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• 1985

Species of scotochromogenic mycobacteria of Group II isolated from sputa of patients with pulmonary tuberculosis and tuberculosis-like diseases from 1979 to 1984 were identified by simple biochemical tests using. nitrate reduction, Tween-80 hydrolysis, arylsulfatase and urease test, and serotypes of the isolates belonging to M. scrofulaceum were differentiated by bacterial agglutination test. Of 39 strains. tested, 11(28.2%) proved to be M. scrofulaceum, 15(38.5%) M. flavescens and 13(33.3%) M. gordonae. But none of the isolates belonged to M. szulgai and M. xenopi known as major pathogens of mycobacteria of Group II. Of 11 strains of the isolates identified as M. scrofulaceum 3 strains(27.3%) each belonged to serotype 41 and 42, and 4 strains(36.4%) belonged to serotype 43, but one strain was not typable because of its inagglutinability by any one of the type specific sera. In addition, the sensitivity and specificity of rabbit immune sera against type strains of serotype 41, 42 and 43 of M. scrofulaceum were analysed by bacterial agglutination test. In the sensitivity of microplate test with 11 isolates of M. scrofulaceum, a comparative tandem test using 2 units and one unit of absorbed antisera against three serotypes appeared to be superior to a conventional microplate test using one unit of type specific antisera.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.169-176
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• 2013

Objectives: The aim of this study is to critically review the health effects of not only direct exposure to biocide, but also indirect exposure to by-product hazardous agents generated through the use of biocide in metalworking operations. Methods: An extensive literature review was conducted of studies reporting on respiratory disease cases, particularly hypersensitivity pneumonitis (HP), in environments using water-soluble metalworking fluids (MWFs). Keyword search terms included 'metalworking fluids', 'machining fluids', 'metalworking operation' 'machining operation' and 'biocide', which were also used in combination. Additional articles were identified in references cited in the articles reviewed. Results: Several of the field, epidemiological and experimental studies reviewed assumed that the symptoms and signs typical of HP developed in machinists who handled water-soluble MWF could be caused by inhalation exposure to nontuberculous mycobacteria (NTM). Most NTM are known to be not only resistant to both biocide and disinfectant, but also to have acid-fast cell walls that are highly antigenic. The presence or persistence of the Mycobacterium species, referred to as NTM, in metalworking fluid-using operations may be caused by NTM contamination in either the natural water or tap water that is used to dilute the base oil and additives for water-soluble MWFs. This hypothesis that NTM contamination in water-soluble MWFs is a causative agent of HP has high biologic plausibility, such as antigenic property, hydrophobicity and small diameter (< 5 um). Conclusions: Aerosolized mycobacteria colonized from MWF are likely to be causing the HP. Inhalation exposure to mycobacteria should be considered as a possible cause for the development of HP.

• Tuberculosis and Respiratory Diseases
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• v.69 no.5
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• pp.331-336
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• 2010

Background: Recently, the rate of infections with non-tuberculous mycobacteria (NTM) has been increasing in Korea. Precise identification of NTM is critical to determination of the pathogen and to target treatment of NTM patients. Methods: Sixty-eight unclassified mycobacteria isolates by rpoB PCR-RFLP assay (PRA) collected in 2008 were analyzed by National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) search after sequencing of 16S rRNA, hsp65, rpoB genes. Results: Nineteen strains of 68 isolates were specified as species after sequencing analysis of 3 gene types. We found 3 M. lentifulavum, 5 M. arupense, 4 M. triviale, 4 M. parascrofulaceum, and one M. obuense. One M. tuberculosis and another M. peregrinum were mutated at the Msp I recognition site needed for rpoB PRA. The remaining 49 isolates did not coincide with identical species at the 3 kinds genes. Conclusion: Sequencing analysis of 16S rRNA, hsp65, rpoB was useful for identification of NTM unclassified by rpoB PRA.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.18-24
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• 2012

Background : Infection caused by rapidly growing mycobacteria (RGM) is not uncommon, and the prevalence of RGM infection has been increasing. Clinical diagnosis is difficult because there are no characteristic clinical features. There is also no standard antibiotic regimen for treating RGM infection. A small series of patients with RGM infections was studied to examine their treatments and outcomes. Methods : A total of 5 patients who had developed postoperative infections from January 2009 to December 2010 were retrospectively reviewed. Patients were initially screened using a mycobacteria rapid screening test (polymerase chain reaction [PCR]-reverse blot hybridization assay). To confirm mycobacterial infection, specimens were cultured for nontuberculous mycobacteria and analyzed by 16 S ribosomal RNA and rpoB gene PCR. Results : The patients were treated with intravenous antibiotics during hospitalization, and oral antibiotics were administered after discharge. The mean duration of follow-up was 9 months, and all patients were completely cured of infection with a regimen of a combination of antibiotics plus surgical treatment. Although none of the patients developed recurrence, there were complications at the site of infection, including hypertrophic scarring, pigmentation, and disfigurement. Conclusions : Combination antibiotic therapy plus drainage of surgical abscesses appeared to be effective for the RGM infections seen in our patients. Although neither the exact dosage nor a standardized regimen has been firmly established, we propose that our treatment can provide an option for the management of rapidly growing mycobacterial infection.