• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.171-176
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• 2019

A comparative study between commercially available mycobacteria growth indicator tubes (MGIT) in the BACTEC MGIT 960 System and the conventional Ogawa media was carried out to assess the effectiveness of the re-decontaminating process for the recovery of mycobacteria. Processed specimens with 5% sodium hydroxide and 0.5% N-acetyl-L-cysteine were inoculated into MGIT and Ogawa media. The acid fast bacilli (AFB) recovered from the cultures were identified using a mycobacterium tuberculosis (TB) antigen kit. If contaminants were observed in the MGIT tubes within five days, a decontaminating process was repeated. A total of 1,190 out of 4,790 (24.8%) specimens showed positive results using the BACTEC MGIT 960 system. Among them, 278 specimens were reprocessed. When the MGIT and Ogawa results were compared, it showed discordant results (weighted kappa value: 0.283). One TB and 10 nontuberculous mycobacteria (NTM) were newly detected in MGIT only. The likely benefit of the re-decontaminating process is the detection of additional mycobacteria that could not be detected without a re-decontaminating process despite being small in number. In addition to the combination of MGIT and Ogawa, the re-decontaminating process is recommended in the case of contaminations to recover mycobacteria.

• 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.72 no.3
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• pp.275-283
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• 2012

Background: Healthy individuals who develop nontuberculous mycobacteria (NTM) lung disease are likely to have specific susceptibility factors which can lead to a NTM infection. The aim of the present study was to investigate the mechanism underlying innate immune responses, including the role of mitogen-activated protein kinase (MAPK), in Mycobacterium abscessus lung disease. Methods: Extracellular signal-regulated kinase (ERK1/2) and p38 MAPK expression in monocytes from peripheral blood mononuclear cells were measured by Western blot analysis after stimulation by Mycobacterium avium in five patients with M. abscessus lung disease and seven healthy controls. A M. avium-induced cytokine assay was performed after inhibition of ERK1/2 and p38 MAPK pathways. Results: Mycobacterium avium induced p38 and ERK1/2 expression in monocytes from healthy controls and subsequently upregulated tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, and IL-10 production. In monocytes from patients with M. abscessus lung disease, however, induction of p38 and ERK1/2 expression, and the production of TNF-${\alpha}$, IL-6, and IL-10 were significantly lower. Conclusion: Decreased activity of MAPK and cytokine secretion in monocytes from patients with M. abscessus lung disease may provide an explanation regarding host susceptibility to these uncommon infections.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.201-206
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• 2010

Nontuberculous mycobacterial (NTM) diseases are increasing worldwide. However NTM lung disease in organ transplant recipients has been rarely reported. Here, we report 2 cases of NTM lung disease in heart transplant recipients. A 37-year-old man, who had undergone a heart transplant one year previous, was admitted to hospital due to a cough. Chest CT scan showed multiple centrilobular nodules in both lower lungs. In his sputum, M. abscessus was repeatedly identified by rpoB gene analysis. The patient improved after treatment with clarithromycin, imipenem, and amikacin. An additional patient, a 53-year-old woman who had undergone a heart transplant 4 years prior and who suffered from bronchiectasis, was admitted because of purulent sputum. The patient's chest CT scan revealed aggravated bronchiectasis; M. intracellulare was isolated repeatedly in her sputum. Treatment was successfully completed with clarithromycin, ethambutol, and ciprofloxacin. NTM lung disease should be considered as a potential opportunistic infection in organ transplant recipients.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1259-1264
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• 2009

We assessed the capacity of two liquid-medium culture methods with automated incubation and reading systems (MB/BacT ALERT 3D System and BACTEC MGIT 960 System) and one solid-medium culture method ($L\ddot{o}wenstein$-Jensen) to detect mycobacteria in different types of clinical samples. Out of 1,770 cultured clinical samples (1,519 of respiratory origin and 251 of non respiratory origin), mycobacteria were isolated in 156 samples (135 M. tuberculosis complex, 8 M. chelonae, 6 M. kansasii, 4 M. fortuitum, 2 M. gordonae, and 1 M. marinum) by at least one of the methods used. The BACTEC MGIT 960 System proved to be the most sensitive method (86.5%), especially in the detection of M. tuberculosis complex (89.1%). However, $L\ddot{o}wenstein$-Jensen culture was the most sensitive (76.2%) to detect nontuberculous mycobacteria. The BACTEC MGIT 960 System showed the lowest mean detection time for mycobacterial growth (15.3 days), significantly shorter than the other two methods. Highest sensitivity (95.5%) and specificity (99.6%) values were obtained using the BACTEC MGIT 960 System with the $L\ddot{o}wenstein$-Jensen culture method, which was also the only combination capable of detecting 100% of the nontuberculous mycobacteria.

• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.87-93
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• 1982

Two cases of pulmonary disease in a 54 year-old female and a 70 year-old male patient due to Mycobacterium avium-intracellulare complex(MAIC) and a case of pulmonary infection ina 69 year-old male patient due to M. fortuitum(MF) were found recently in this institute. All three patients had a long history of anti-tuberculous chemotherapy because they were initially diagnosed as pulmonary tuberculosis. A 70 year-old male patient infected with MAIC had an unsuccessful chemotherapy history of isoniazid(INH), para-aminosalicylic acid(PAS) and streptomycin(SM) with an incomplete, temporary, symptomatic improvement, for three years since 1964 when he was first diagnosed as pulmonary tuberculosis on physical examination. A 54 year-old female patient infected with MAIC also had an unsuccessful chemotherapy history with the various anti-tuberculous drugs since 1958. Both patients discharged large number of MAIC in their sputum specimens for at least more than one year, but no M. tuberculosis at all. A 69 year-old male patient infected with MF was diagnosed as moderately advanced pulmonary tuberculsis in 1977. Combined chemotherapy with INH+PAS+pyrazinamide(PZA) improved his clinical symptoms, however, his chest radiograph was deteriorated again in 1980 one year after he stopped therapy. Therefore he started chemotherapy again with INH+ethionamide(TH)+cycloserine(CS) but no improvement was noticed. MF was cultured from his sputum in August 1981 and he continuously discharged the same bacilli until last examination of January 1982. Whether all three patients were initially !infected with nontuberculous mycobacteria or complicated with predisposing tuberculosis was not clear because there were no reliable bacteriological examination records.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.697-703
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• 1999

Mycobacterium celatum is a recently described nontuberculous mycobacterium. Even though pulmonary or lymphatic infection cases were reported previously in human, the clinical significance of the infection with M. celatum is not yet understood completely. Mast infections with this species occurred in the patients with suppressed cell-mediated immunity such as AIDS, and there are only a few cases of pulmonary infection with M. celatum in immunocompetent adults or infants in the world. In Korea, mycobacterial pulmonary infection is a major problem of respiratory disease but, there has been no pulmonary infection with M. celatum reported. We report, to our knowledge, the first Korean case of pulmonary infection with M. celatum, which was identified by rpoB genomic sequencing.

• Tuberculosis and Respiratory Diseases
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• v.75 no.1
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• pp.28-31
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• 2013

Methotrexate (MTX) has been established as a standard disease-modifying anti-rheumatic drug. If adequate disease control is achieved for a reasonable period of time, tapering the MTX dosage is recommended because the chronic use of MTX can result in opportunistic infection. We present here a case of a woman with rheumatoid arthritis taking MTX, and the woman developed actively caseating endobronchial Mycobacterium intracellulare disease with pulmonary infiltrations. After discontinuing the MTX, the patient was able to tolerate 18 months of antimycobacterial treatment without flare ups of rheumatoid arthritis, and she completely recovered from nontuberculous mycobacterial respiratory disease.

• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.73-77
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• 2017

An 81 year-old male patient presented with rapid enlargement of left lateral neck mass, diagnosed two months earlier as cervical nontuberculous mycobacterial lymphadenitis. Abscess formation and impending rupture related to aggravation of nontuberculous mycobacterial lymphadenitis was highly suspected. Unexpectedly, blood flow was detected by Doppler ultrasonography, which indicated possible vascular mass. Computed tomography demonstrated a $6.0cm{\times}4.0cm$ sized enhancing mass consistent with pseudoaneurysm of internal carotid artery. The patient underwent pseudoaneurysmectomy. Surgical drainage without adequate evaluation might have led to potentially life-threatening condition. We describe this rare case with importance of imaging screening in a neck mass.

• 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.