• 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 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.

• 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 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.

• Journal of Mushroom
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• v.9 no.4
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• pp.190-193
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• 2011

Inonotus obliquus is a traditional medicine mushroom that was developed from traditional medicine originating in ancient. It has been applied for cancer or immunotherapy, but its effect on pulmonary tuberculosis is not reported. Therefore, we measured the pulmonary tuberculosis therapeutic effect of methyl alcohol extract from MGIT 960 system with fluorescent indicator. Inonotus obliquus extract showed 14 day more inhibitory activity than the positive control. In addition, the anti-pulmonary tuberculosis activity of Inonotus obliquus was $50{\mu}m$. These results suggest that Inonotus obliquus methyl alcohol extracts could contribute to inhibition of pulmonary tuberculosis.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.201-207
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• 2020

In this study, the practicality of unmanned aerial vehicle photography information was identified. Therefore, a total of four consecutive surveys were conducted on the field-level survey areas among the areas subject to photography using unmanned aerial vehicles, and the changes in crop conditions were analyzed using pictures of unmanned aerial vehicles taken during each survey. It is appropriate to collect and utilize photographic information by directly taking pictures of the survey area according to the time of the on-site survey using unmanned aerial vehicles in the field layer, which is an area where many changes in topography, crop vegetation, and crop types are expected. And it turned out that it was appropriate to utilize satellite images in consideration of economic and efficient aspects in relatively unchanged rice paddies and facilities. If the survey area is well equipped with systems for crop cultivation, deep learning can be utilized in real time by utilizing libraries after obtaining photographic data for a certain area using unmanned aircraft in the future. Through this process, it is believed that it can be used to analyze the overall crop and shipment volume by identifying the crop status and surveying the quantity per unit area.

• Molecules and Cells
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• v.38 no.7
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• pp.610-615
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• 2015

Alveolar epithelial cells have been functionally implicated in Mycobacterium tuberculosis infection. This study investigated the role of ursolic acid (UA)-a triterpenoid carboxylic acid with potent antioxidant, anti-tumor, anti-inflammatory, and anti-tuberculosis properties in mycobacterial infection of alveolar epithelial A549 cells. We observed that M. tuberculosis successfully entered A549 cells. Cytotoxicity was mediated by nitric oxide (NO). A549 toxicity peaked along with NO generation 72 h after infection. The NO generated by mycobacterial infection in A549 cells was insufficient to kill mycobacteria, as made evident by the mycobacteria growth indicator tube time to detect (MGIT TTD) and viable cell count assays. Treatment of mycobacteria-infected cells with UA reduced the expression of inducible nitric oxide synthase, NO generation, and eventually improved cell viability. Moreover, UA was found to quench the translocation of the transcription factor, nuclear factor kappa B (NF-${\kappa}B$), from the cytosol to the nucleus in mycobacteria-infected cells. This study is the first to demonstrate the cytotoxic role of NO in the eradication of mycobacteria and the role of UA in reducing this cytotoxicity in A549 cells.

• 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.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.738-744
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• 2015

Tuberculosis is one of the most threatening infectious diseases to public health all over the world, for which Mycobacterium tuberculosis (MTB) is the etiological agent of pathogenesis. Ursolic acid (UA) has immunomodulatory function and exhibits antimycobacterial activity. However, the intracellular killing effect of UA has yet to be elucidated. The aim of this study was to evaluate the intracellular killing effect of UA during mycobacterial infection. The intracellular killing activity of UA was evaluated in the macrophage cell line THP-1 by the MGIT 960 system as well as by CFU count. The production of reactive oxygen species (ROS) and the level of nitric oxide (NO) were measured using DCF-DA and Griess reagent, respectively. Phagocytosis was observed by a fluorescence-based staining method, and the colony forming units were enumerated on 7H11 agar medium following infection. In addition, MRP8 mRNA expression was measured by qRT-PCR. UA significantly decreased the number of intracellular Mycobacterium through generation of ROS and NO. In addition, it profoundly activated the phagocytosis process of THP-1 cells during MTB-infection. Furthermore, our data demonstrated that UA activated the phagocytosis process in human monocyte cells through MRP8 induction. These data suggest that UA firmly contributes to the intracellular killing effect of macrophages during mycobacterial infection.

• Tuberculosis and Respiratory Diseases
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• v.83 no.4
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• pp.289-294
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• 2020

Background: Line probe assay (LPA) is standard diagnostic tool to detect multidrug resistant tuberculosis. Non-interpretable (NI) results in LPA (complete missing or light wild-type 3 and 8 bands with no mutation band in rpoB gene region) poses a diagnostic challenge. Methods: Sputum samples obtained between October 2016 and July 2017 at the Intermediate Reference Laboratory, All India Institute of Medical Sciences Hospital, New Delhi, India were screened. Smear-positive and smear-negative culture-positive specimens were subjected to LPA Genotype MTBDRplus Ver 2.0. Smear-negative with culture-negative and culture contamination were excluded. LPA NI samples were subjected to phenotypic drug susceptibility testing (pDST) using MGIT-960 and sequencing. Results: A total of 1,614 sputum specimens were screened and 1,340 were included for the study (smear-positive [n=1,188] and smear-negative culture-positive [n=152]). LPA demonstrated 1,306 (97.5%) valid results with TUB (Mycobacterium tuberculosis) band, 24 (1.8%) NI, three (0.2%) valid results without TUB band, and seven (0.5%) invalid results. Among the NI results, 22 isolates (91.7%) were found to be rifampicin (RIF) resistant and two (8.3%) were RIF sensitive in the pDST. Sequencing revealed that rpoB mutations were noted in all 22 cases with RIF resistance, whereas the remaining two cases had wild-type strains. Of the 22 cases with rpoB mutations, the most frequent mutation was S531W (n=10, 45.5%), followed by S531F (n=6, 27.2%), L530P (n=2, 9.1%), A532V (n=2, 9.1%), and L533P (n=2, 9.1%). Conclusion: The present study showed that the results of the Genotype MTBDRplus assay were NI in a small proportion of isolates. pDST and rpoB sequencing were useful in elucidating the cause and clinical meaning of the NI results.