• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1221-1229
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• 2019

Mycobacterium tuberculosis, a causative pathogen of tuberculosis (TB), still threatens human health worldwide. To find a novel drug to eradicate this pathogen, we tested taurine-5-bromosalicylaldehyde Schiff base (TBSSB) as an innovative anti-mycobacterial drug using Mycobacterium smegmatis as a surrogate model for M. tuberculosis. We investigated the antimicrobial activity of TBSSB against M. smegmatis by plotting growth curves, examined the effect of TBSSB on biofilm formation, observed morphological changes by scanning electron microscopy and transmission electron microscopy, and detected differentially expressed proteins using two-dimensional gel electrophoresis coupled with mass spectrometry. TBSSB inhibited mycobacterial growth and biofilm formation, altered cell ultrastructure and intracellular content, and inhibited cell division. Furthermore, M. smegmatis adapted itself to TBSSB inhibition by regulating the metabolic pathways and enzymatic activities of the identified proteins. NDMA-dependent methanol dehydrogenase, NAD(P)H nitroreductase, and amidohydrolase AmiB1 appear to be pivotal factors to regulate the M. smegmatis survival under TBSSB. Our dataset reinforced the idea that Schiff base-taurine compounds have the potential to be developed as novel anti-mycobacterial drugs.

• Journal of Life Science
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• v.20 no.4
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• pp.578-583
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• 2010

It has been reported that extracts of globe thistle (Echinops spp.) and thistle (Circium spp., Carduus spp. and Onopordum spp.) have anti-bacterial and anti-fungal activities. Methanol extracts of Echinops setifer and Carduus spp. were used to test and see if the extracts of these plants could suppress growth of Mycobacterium smegmatis and Mycobacterium fortuitum. Although extract of Echinops setifer showed no anti-mycobacterial activities, extract of Carduus spp. showed inhibition zones when tested with filter discs. Genomic DNA was isolated from Carduus spp. and PCR was performed to clone a DNA fragment containing ITS1, 5.8S rRNA gene and ITS2. A 733-bp PCR product was obtained and its DNA sequence was reported to the GenBank (accession number GU188570). BLAST search of the obtained DNA sequence did not show a match with any DNA sequences in the Genbank. Carduus crispus and Carduus defloratus had the closest phylogenetic relationships to this plant.

• Journal of the Korean Chemical Society
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• v.66 no.3
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• pp.194-201
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• 2022

A simple, efficient, and cost-effective method has been employed for the synthesis of 2,4,5-trisubstituted imidazole derivatives (3a-j) containing quinoline substituent at 2^nd position. Title compounds were obtained by multicomponent reaction (MCR), involving aryl substituted 1,2-diketone, quinoline carbaldehyde and ammonium acetate in the presence of acetic acid solvent under mild reaction conditions. The newly synthesized quinoline containing imidazole derivatives were confirmed through FT-IR, ¹H-NMR, ¹³C-NMR and mass spectral analysis. In-vitro microplate alamar blue assay (MABA) to determine the MIC (minimum inhibitory concentration) values against Mycobacterium tuberculosis H37Rv was performed for the synthesized compounds. The synthesized compounds exhibited activity against Mycobacterium tuberculosis and among which compounds, 3d, 3f and 3i showed good activity. The highest activity was showed with compound 3i. The anti-mycobacterial activity results are well correlated with the computational molecular docking analysis, which was performed for the synthesized compounds prior to the evaluation of the activity.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.946-950
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• 2015

Recently, it has become a struggle to treat tuberculosis with the current commercial antituberculosis drugs because of the increasing emergence of multidrug-resistant (MDR) tuberculosis and extensively drug-resistant (XDR) tuberculosis. We evaluated here the antimycobacterial activity of tamoxifen, known as a synthetic anti-estrogen, against eight drugsensitive or resistant strains of Mycobacterium tuberculosis (TB), and the active intracellular killing of tamoxifen on TB in macrophages. The results showed that tamoxifen had antituberculosis activity against drug-sensitive strains (MIC, 3.125-6.25 µg/ml) as well as drugresistant strains (MIC, 6.25 to 12.5 µg/ml). In addition, tamoxifen profoundly decreased the number of intracellular TB in macrophages in a dose-dependent manner.

• Journal of Microbiology
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• v.44 no.1
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• pp.121-125
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• 2006

Mycothiol is a low molecular weight thiol compound produced by a number of actinomycetes, and has been suggested to serve both anti-oxidative and detoxifying roles. To investigate the metabolism and the role of mycothiol in Streptomyces coelicolor, the biosynthetic genes (mshA, B, C, and D) were predicted based on sequence homology with the mycobacterial genes and confirmed experimentally. Disruption of the mshA, C, and D genes by PCR targeting mutagenesis resulted in no synthesis of mycothiol, whereas the mshB mutation reduced its level to about $10\%$ of the wild type. The results indicate that the mshA, C, and D genes encode non-redundant biosynthetic enzymes, whereas the enzymatic activity of MshB (acetylase) is shared by at least one other gene product, most likely the mca gene product (amidase).

• Korean Journal of Clinical Laboratory Science
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• v.54 no.2
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• pp.125-132
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• 2022

The prevalence of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) are increasing. We analyzed the patterns of drug resistance and tracking period days of acquiring anti-mycobacterial resistance. From January 2010 to December 2019, drug susceptibility tests (DST) were performed by the absolute concentration method using the Löwenstein-Jensen solid medium and pyrazinamidase activity test (to assess pyrazinamide resistance) in samples from patients who were referred to the Green Cross Laboratories in Yongin. Among the cases that showed resistance to one or more anti-tuberculosis drugs, 55 patients (33.1%) were resistant to isoniazid (INH) at the time of initial referral, and the rates for the development of resistant anti-tuberculosis drugs were ethambutol (EMB) (26.6%), rifampicin (RFP) (21.9%), quinolones (QUI) (21.9%) and pyrazinamide (PZA) (10.9%), in that order. In the cases sensitive to all 10 anti-tuberculosis drugs initially, the development of resistance to INH was the most frequent, seen in 43 patients (7.2%). The average follow-up period was 435.6 days, and the resistance development was observed in the order of INH (7.2%), RFP (3.9%), SM (1.9%), QUI (0.7%), amikacin (AMK) (0.5%), and EMB (0.5%). The conversion of susceptible strains to resistant strains is an important warning sign for the patient, especially in cases of conversion to MDR or XDR. This information would be helpful for improving patient care during TB treatment.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.94-99
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• 2014

The present study aimed to evaluate the in vitro antimycobacterial effects of hop plant, Humulus japonicus. Methanol extract of H. japonicus (MeOH extract) showed strong direct bactericidal effects against Mycobacterium tuberculosis in vitro. Furthermore, the MeOH extract significantly inhibited M. tuberculosis growth in human macrophages. When five fractions obtained from MeOH extract were examined using the same methods, the hexane and ethyl acetate fractions showed bactericidal effects against M. tuberculosis in vitro, whereas the butanol and water fractions inhibited M. tuberculosis growth in macrophages. Because H. japonicus extract exhibited antimycobacterial activity against both free M. tuberculosis in culture medium and intracellular M. tuberculosis in human macrophages, this plant might be a good candidate for development of a new anti-tuberculosis drug.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.36-44
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• 1998

Background: IFN-$\gamma$ is known to activate mononuclear phagocytes and to mediate host defense mechanism against some intracellular microorganisms, but little is known about anti-mycobacterial activity and mechanism of IFN-$\gamma$ in human. In this study, we investigated the role of IFN-$\gamma$ in the pathogenesis of tuberculosis by observing the effect of IFN-$\gamma$ on the phagocytosis of M.tuberculosis(MTB) and on the production of TNF-$\alpha$ by human pulmonary alveolar macrophage. Method: Pulmonary alveolar macrophage(PAM) were prepared with adhesion purification method from bronchoalveolar lavage fluid obtained from 8 persorn without active lung lesion and cultured($1{\times}10^6cells/ml$) with MTB($3{\times}10^7$ bacteria/ml) with or without IFN-$\gamma$(300U/ml), LPS(0.5ug/ml) and autologous serum(10%). After 2 hours, the percentage of PAM-phagocytosed MTB was counted after AFB staining(modified Kynion method). TNF-$\alpha$ production by PAM stimulated by IFN-$\gamma$(300U/ml), MTB($1{\times}10^6bacteria/ml$) and LPS(0.5ug/ml) for 24hours was measured in culture supernatant using ELISA method. The degree of phagocytosis of MTB by PAM stimulated with IFN-$\gamma$(300U/ml) and LPS(0.5ug/ml) for 24hours was also investigated. Results: IFN-$\gamma$ did not influence the phagocytosis of MTB by PAM(percentage of PAM-phagocytosed MTB: control: $22.1{\pm}4.9$, IFN-$\gamma$: $20.3{\pm}5.3$) and did not increase TNF-$\alpha$ production by PAM (control: $21{\pm}38pg/ml$, IFN-$\gamma$: $87{\pm}106pg/ml$), and the degree of phagocytosis of MTB by PAM pre-stimulated with IFN-$\gamma$ for 24 hours, was not increased (control: $24.5{\pm}9.5$, IFN-$\gamma$: $23.4{\pm}10.1$). Conclusion: IFN-$\gamma$ does not influence on the phagocytosis of MTB and TNF-$\alpha$ production by PAM.