Displaying publications 1 - 20 of 201 in total

Abstract:
Sort:
  1. del Amo J, Moreno S, Bucher HC, Furrer H, Logan R, Sterne J, et al.
    Clin Infect Dis, 2012 May;54(9):1364-72.
    PMID: 22460971 DOI: 10.1093/cid/cis203
    BACKGROUND: The lower tuberculosis incidence reported in human immunodeficiency virus (HIV)-positive individuals receiving combined antiretroviral therapy (cART) is difficult to interpret causally. Furthermore, the role of unmasking immune reconstitution inflammatory syndrome (IRIS) is unclear. We aim to estimate the effect of cART on tuberculosis incidence in HIV-positive individuals in high-income countries.

    METHODS: The HIV-CAUSAL Collaboration consisted of 12 cohorts from the United States and Europe of HIV-positive, ART-naive, AIDS-free individuals aged ≥18 years with baseline CD4 cell count and HIV RNA levels followed up from 1996 through 2007. We estimated hazard ratios (HRs) for cART versus no cART, adjusted for time-varying CD4 cell count and HIV RNA level via inverse probability weighting.

    RESULTS: Of 65 121 individuals, 712 developed tuberculosis over 28 months of median follow-up (incidence, 3.0 cases per 1000 person-years). The HR for tuberculosis for cART versus no cART was 0.56 (95% confidence interval [CI], 0.44-0.72) overall, 1.04 (95% CI, 0.64-1.68) for individuals aged >50 years, and 1.46 (95% CI, 0.70-3.04) for people with a CD4 cell count of <50 cells/μL. Compared with people who had not started cART, HRs differed by time since cART initiation: 1.36 (95% CI, 0.98-1.89) for initiation <3 months ago and 0.44 (95% CI, 0.34-0.58) for initiation ≥3 months ago. Compared with people who had not initiated cART, HRs <3 months after cART initiation were 0.67 (95% CI, 0.38-1.18), 1.51 (95% CI, 0.98-2.31), and 3.20 (95% CI, 1.34-7.60) for people <35, 35-50, and >50 years old, respectively, and 2.30 (95% CI, 1.03-5.14) for people with a CD4 cell count of <50 cells/μL.

    CONCLUSIONS: Tuberculosis incidence decreased after cART initiation but not among people >50 years old or with CD4 cell counts of <50 cells/μL. Despite an overall decrease in tuberculosis incidence, the increased rate during 3 months of ART suggests unmasking IRIS.

    Matched MeSH terms: Mycobacterium tuberculosis/isolation & purification
  2. Yoon YK, Ali MA, Wei AC, Choon TS, Ismail R
    Eur J Med Chem, 2015 Mar 26;93:614-24.
    PMID: 24996257 DOI: 10.1016/j.ejmech.2013.06.025
    A total of 51 novel benzimidazoles were synthesized by a 4-step reaction starting from basic compound 4-fluoro-3-nitrobenzoic acid under relatively mild reaction conditions. The structure of the novel benzimidazoles was confirmed by mass spectra as well as (1)H NMR spectroscopic data. Out of the 51 novel synthesized compounds, 42 of them were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain using BacTiter-Glo™ Microbial Cell Viability (BTG) method. Results of activity screened using Alamar Blue method was also provided for comparison purposes. Two of the novel benzimidazoles synthesized showed moderately good activity with IC50 of less than 15 μM. Compound 5g, ethyl 2-(4-(trifluoromethyl)phenyl)-1-(2-morpholinoethyl)-1H-benzo[d]imidazole-5-carboxylate, was found to be the most active with IC50 of 11.52 μM.
    Matched MeSH terms: Mycobacterium tuberculosis/drug effects*
  3. Yong YK, Tan HY, Saeidi A, Wong WF, Vignesh R, Velu V, et al.
    Front Microbiol, 2019;10:2789.
    PMID: 31921004 DOI: 10.3389/fmicb.2019.02789
    Tuberculosis (TB) treatment monitoring is paramount to clinical decision-making and the host biomarkers appears to play a significant role. The currently available diagnostic technology for TB detection is inadequate. Although GeneXpert detects total DNA present in the sample regardless live or dead bacilli present in clinical samples, all the commercial tests available thus far have low sensitivity. Humoral responses against Mycobacterium tuberculosis (Mtb) antigens are generally low, which precludes the use of serological tests for TB diagnosis, prognosis, and treatment monitoring. Mtb-specific CD4+ T cells correlate with Mtb antigen/bacilli burden and hence might serve as good biomarkers for monitoring treatment progress. Omics-based techniques are capable of providing a more holistic picture for disease mechanisms and are more accurate in predicting TB disease outcomes. The current review aims to discuss some of the recent advances on TB biomarkers, particularly host biomarkers that have the potential to diagnose and differentiate active TB and LTBI as well as their use in disease prognosis and treatment monitoring.
    Matched MeSH terms: Mycobacterium tuberculosis
  4. Yano K, Goto S, Sado M, Takeuchi M, Iguchi M
    PMID: 4215145
    Matched MeSH terms: Mycobacterium tuberculosis/isolation & purification
  5. Yakubu Y, Ong BL, Zakaria Z, Hassan L, Mutalib AR, Ngeow YF, et al.
    Prev Vet Med, 2016 Mar 1;125:147-53.
    PMID: 26775804 DOI: 10.1016/j.prevetmed.2016.01.008
    Elephant tuberculosis (TB) caused by Mycobacterium tuberculosis is an important re-emerging zoonosis with considerable conservation and public health risk. We conducted prospective cohort and cross-sectional studies in elephants and wildlife staff respectively in order to identify potential risk factors associated with TB in captive Asian elephants and their handlers in Peninsular Malaysia. Sixty elephants in six different facilities were screened for TB longitudinally using the ElephantTB STAT-PAK and DPP VetTB assays from February 2012 to May 2014, and 149 wildlife staff were examined for tuberculosis infection using the QuantiFERON-TB Gold In-tube (QFT) assay from January to April, 2012. Information on potential risk factors associated with infection in both elephants and staff were collected using questionnaires and facility records. The overall seroprevalence of TB amongst the elephants was 23.3% (95% CI: 13.8-36.3) and the risk of seroconversion was significantly higher among elephants with assigned mahouts [p=0.022, OR=4.9 (95% CI: 1.3-18.2)]. The percentage of QFT responders among wildlife staff was 24.8% (95% CI: 18.3-32.7) and the risk of infection was observed to be significantly associated with being a zoo employee [p=0.018, OR=2.7 (95% CI: 1.2-6.3)] or elephant handler [p=0.035, OR=4.1 (95% CI: 1.1-15.5)]. These findings revealed a potential risk of TB infection in captive elephants and handlers in Malaysia, and emphasize the need for TB screening of newly acquired elephants, isolating sero-positive elephants and performing further diagnostic tests to determine their infection status, and screening elephant handlers for TB, pre- and post-employment.
    Matched MeSH terms: Mycobacterium tuberculosis
  6. Xu S, Xue Y, Guo F, Xu M, Gopinath SCB, Mao X
    3 Biotech, 2020 May;10(5):227.
    PMID: 32373419 DOI: 10.1007/s13205-020-02216-2
    Herein, a rapid and sensitive current-volt measurement was developed for identifying the IS6110 DNA sequence to diagnose Mycobacterium tuberculosis (TB). An aminated capture probe was immobilized on a 1,1'-carbonyldiimidazole-functionalized interdigitated electrode (IDE) silica substrate, and the target sequence was detected by complementation. It was found that all tested concentrations displayed a higher response in current changes than the control, and the limit of detection was 10 fM. The sensitivity ranged from 1 to 10 fM. The control sequences with single-, triple-mismatch and noncomplementary sequences showed great discrimination. This rapid and easy DNA detection method helps to identify M. tuberculosis for early-stage diagnosis of TB.
    Matched MeSH terms: Mycobacterium tuberculosis
  7. Wong KT, Osman H, Parumasivam T, Supratman U, Che Omar MT, Azmi MN
    Molecules, 2021 Apr 05;26(7).
    PMID: 33916423 DOI: 10.3390/molecules26072081
    A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (1H, 13C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c-5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand-receptor interactions, and to hypothesize potential refinements for the compound.
    Matched MeSH terms: Mycobacterium tuberculosis
  8. Wei AC, Ali MA, Yoon YK, Ismail R, Choon TS, Kumar RS, et al.
    Bioorg Med Chem Lett, 2012 Aug 1;22(15):4930-3.
    PMID: 22749825 DOI: 10.1016/j.bmcl.2012.06.047
    A series of twelve dispiropyrrolidines were synthesized using [3+2]-cycloaddition reactions. The synthesized compounds were screened for their antimycobacterial activity against M. tuberculosis H(37)Rv and INH resistant M. tuberculosis strains using agar dilution method, four of them showed good activity with MIC of less than 1 μM. Compound 4'-[5-(4-fluorophenyl)pyridin-3-yl]-1'-methyldispiro[indan-2,2' pyrrolidine-3',2″-indan]-1,3,1″-trione (4b) was found to be the most active with MIC of 0.1215 and 5.121 μM, respectively.
    Matched MeSH terms: Mycobacterium tuberculosis/drug effects
  9. Wahab HA, Choong YS, Ibrahim P, Sadikun A, Scior T
    J Chem Inf Model, 2009 Jan;49(1):97-107.
    PMID: 19067649 DOI: 10.1021/ci8001342
    The continuing rise in tuberculosis incidence and the problem of drug resistance strains have prompted the research on new drug candidates and the mechanism of drug resistance. Molecular docking and molecular dynamics simulation (MD) were performed to study the binding of isoniazid onto the active site of Mycobacterium tuberculosis enoyl-acyl carrier protein reductase (InhA) in an attempt to address the mycobacterial resistance against isoniazid. Results show that isonicotinic acyl-NADH (INADH) has an extremely high binding affinity toward the wild type InhA by forming stronger interactions compared to the parent drug (isoniazid) (INH). Due to the increase of hydrophobicity and reduction in the side chain's volume of A94 of mutant type InhA, both INADH and the mutated protein become more mobile. Due to this reason, the molecular interactions of INADH with mutant type are weaker than that observed with the wild type. However, the reduced interaction caused by the fluctuation of INADH and the mutant protein only inflected minor resistance in the mutant strain as inferred from free energy calculation. MD results also showed there exists a water-mediated hydrogen bond between INADH and InhA. However, the bridged water molecule is only present in the INADH-wild type complex, reflecting the putative role of the water molecule in the binding of INADH to the wild type protein. The results support the assumption that the conversion of prodrug isoniazid into its active form INADH is mediated by KatG as a necessary step prior to target binding on InhA. Our findings also contribute to a better understanding of INH resistance in mutant type.
    Matched MeSH terms: Mycobacterium tuberculosis/drug effects; Mycobacterium tuberculosis/enzymology; Mycobacterium tuberculosis/genetics
  10. Verma R, Boshoff HIM, Arora K, Bairy I, Tiwari M, Varadaraj BG, et al.
    Drug Dev Res, 2020 05;81(3):315-328.
    PMID: 31782209 DOI: 10.1002/ddr.21623
    A new series of novel triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether) analogues were designed, synthesized, and screened for their in vitro antimycobacterial and antibacterial activities. Most of the compounds showed significant activity against Mycobacterium tuberculosis H37Rv strain with minimum inhibitory concentration (MIC) values in 20-40 μM range in GAST/Fe medium when compared with triclosan (43 μM) in the first week of assay, and after additional incubation, seven compounds, that is, 2a, 2c, 2g, 2h, 2i, 2j, and 2m, exhibited MIC values at the concentration of 20-40 μM. The compounds also showed more significant activity against Bacillus subtilis and Staphylococcus aureus. The synthesized compounds showed druggable properties, and the predicted ADME (absorption, distribution, metabolism, and excretion) properties were within the acceptable limits. The in silico studies predicted better interactions of compounds with target protein residues and a higher dock score in comparison with triclosan. Molecular dynamics simulation study of the most active compound 2i was performed in order to further explore the stability of the protein-ligand complex and the protein-ligand interaction in detail.
    Matched MeSH terms: Mycobacterium tuberculosis
  11. Venugopala KN, Chandrashekharappa S, Pillay M, Abdallah HH, Mahomoodally FM, Bhandary S, et al.
    PLoS One, 2019;14(6):e0217270.
    PMID: 31163040 DOI: 10.1371/journal.pone.0217270
    Indolizines are heteroaromatic compounds, and their synthetic analogues have reportedly showed promising pharmacological properties. In this study, a series of synthetic 7-methoxy-indolizine derivatives were synthesised, characterised and evaluated for in vitro whole-cell anti-tuberculosis (TB) screening against susceptible (H37Rv) and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) using the resazurin microplate assay method. The cytotoxicity was evaluated using the MTT assay. In silico molecular-docking study was conducted for compounds 5a-j against enoyl-[acyl-carrier] protein reductase, a key enzyme of the type II fatty acid synthesis that has attracted much interest for the development of novel anti-TB compounds. Thereafter, molecular dynamic (MD) simulation was undertaken for the most active inhibitors. Compounds 5i and 5j with the methoxy functional group at the meta position of the benzoyl group, which was at the third position of the indolizine nucleus, demonstrated encouraging anti-TB activity against MDR strains of MTB at 16 μg/mL. In silico studies showed binding affinity within the range of 7.07-8.57 kcal/mol, with 5i showing the highest binding affinity. Hydrogen bonding, π-π- interactions, and electrostatic interactions were common with the active site. Most of these interactions occurred with the catalytic amino acids (Pro193, Tyr158, Phe149, and Lys165). MD simulation showed that 5j possessed the highest binding affinity toward the enzyme, according to the two calculation methods (MM/PBSA and MM/GBSA). The single-crystal X-ray studies of compounds 5c and 5d revealed that the molecular arrangements in these two structures were mostly guided by C-H···O hydrogen-bonded dimeric motifs and C-H···N hydrogen bonds, while various secondary interactions (such as π···π and C-H···F) also contributed to crystal formation. Compounds 5a, 5c, 5i, and 5j exhibited no toxicity up to 500 μg/mL. In conclusion, 5i and 5j are promising anti-TB compounds that have shown high affinity based on docking and MD simulation results.
    Matched MeSH terms: Mycobacterium tuberculosis/growth & development*
  12. Tye GJ, Lew MH, Choong YS, Lim TS, Sarmiento ME, Acosta A, et al.
    J Immunol Res, 2015;2015:916780.
    PMID: 26146643 DOI: 10.1155/2015/916780
    Development of vaccines for infectious diseases has come a long way with recent advancements in adjuvant developments and discovery of new antigens that are capable of eliciting strong immunological responses for sterile eradication of disease. Tuberculosis (TB) that kills nearly 2 million of the population every year is also one of the highlights of the recent developments. The availability or not of diagnostic methods for infection has implications for the control of the disease by the health systems but is not related to the immune surveillance, a phenomenon derived from the interaction between the bacteria and their host. Here, we will review the immunology of TB and current vaccine candidates for TB. Current strategies of developing new vaccines against TB will also be reviewed in order to further discuss new insights into immunotherapeutic approaches involving adjuvant and antigens combinations that might be of potential for the control of TB.
    Matched MeSH terms: Mycobacterium tuberculosis/immunology*
  13. Tirado Y, Puig A, Alvarez N, Borrero R, Aguilar A, Camacho F, et al.
    Tuberculosis (Edinb), 2016 12;101:44-48.
    PMID: 27865396 DOI: 10.1016/j.tube.2016.07.017
    Tuberculosis (TB) remains an important cause of mortality and morbidity. The TB vaccine, BCG, is not fully protective against the adult form of the disease and is unable to prevent its transmission although it is still useful against severe childhood TB. Hence, the search for new vaccines is of great interest. In a previous study, we have shown that proteoliposomes obtained from Mycobacterium smegmatis (PLMs) induced cross reactive humoral and cellular response against Mycobacterium tuberculosis (Mtb) antigens. With the objective to evaluate the protective capability of PLMs, a murine model of progressive pulmonary TB was used. Animals immunized with PLMs with and without alum (PLMs/PLMsAL respectively) showed protection compared to non-immunized animals. Mice immunized with PLMsAL induced similar protection as that of BCG. Animals immunized with BCG, PLMs and PLMsAL showed a significant decrease in tissue damage (percentage of pneumonic area/lung) compared to non-immunized animals, with a more prominent effect in BCG vaccinated mice. The protective effect of the administration of PLMs in mice supports its future evaluation as experimental vaccine candidate against Mtb.
    Matched MeSH terms: Mycobacterium tuberculosis/growth & development; Mycobacterium tuberculosis/isolation & purification
  14. Tang TH, Ahmed SA, Musa M, Zainuddin ZF
    World J Microbiol Biotechnol, 2013 Dec;29(12):2389-95.
    PMID: 23807412 DOI: 10.1007/s11274-013-1407-0
    Although the multi-copy and specific element IS6110 provides a good target for the detection of Mycobacterium tuberculosis complex by PCR techniques, the emergence of IS6110-negative strains suggested that false negative may occur if IS6110 alone is used as the target for detection. In this report, a multiplex polymerase chain reaction (mPCR) system was developed using primers derived from the insertion sequence IS6110 and an IS-like elements designated as B9 (GenBank accession no. U78639.1) to overcome the problem of detecting negative or low copy IS6110 containing strains of M. tuberculosis. The mPCR was evaluated using 346 clinical samples which included 283 sputum, 19 bronchial wash, 18 pleural fluid, 9 urine, 7 CSF, 6 pus, and 4 gastric lavage samples. Our results showed that the sensitivity (93.1 %) and specificity (89.6 %) of the mPCR system exceeds that of the conventional method of microscopy and culture. The mPCR assay provides an efficient strategy to detect and identify M. tuberculosis from clinical samples and enables prompt diagnosis when rapid identification of infecting mycobacteria is necessary.
    Matched MeSH terms: Mycobacterium tuberculosis/classification; Mycobacterium tuberculosis/genetics; Mycobacterium tuberculosis/isolation & purification*
  15. Tan, Sun Mee, Wong, K.J., Fong, S.M.
    MyJurnal
    Tuberculosis in children remains a public heath concern in Malaysia and other developing countries. Mycobacterium tuberculosis (TB) infection of the liver, known as hepatic TB, is an extra pulmonary manifestation of TB. Tuberculous bacilli can reach the liver via hematogenous dissemination through hepatic artery, or by local spread from the gastrointestinal tract via portal vein [1].(Copied from article)
    Matched MeSH terms: Mycobacterium tuberculosis
  16. Tan KT, Kannan SK, Rajahram GS
    Med J Malaysia, 2019 12;74(6):547-548.
    PMID: 31929486
    Tuberculosis is a nimble chameleon. It can manifest itself in various ways with atypical clinical and radiographic findings. In this report we discuss the importance of radiographic findings (nodular or mass-like forms) requiring a correlation with microbiological and histopathological results to differentiate lung cancer from TB.
    Matched MeSH terms: Mycobacterium tuberculosis/isolation & purification*
  17. Tan JL, Simbun A, Chan KG, Ngeow YF
    Sci Data, 2020 05 05;7(1):135.
    PMID: 32371951 DOI: 10.1038/s41597-020-0475-x
    Mycobacterium tuberculosis (MTB) is commonly used as a model to study pathogenicity and multiple drug resistance in bacteria. These MTB characteristics are highly dependent on the evolution and phylogeography of the bacterium. In this paper, we describe 15 new genomes of multidrug-resistant MTB (MDRTB) from Malaysia. The assessments and annotations on the genome assemblies suggest that strain differences are due to lineages and horizontal gene transfer during the course of evolution. The genomes show mutations listed in current drug resistance databases and global MTB collections. This genome data will augment existing information available for comparative genomic studies to understand MTB drug resistance mechanisms and evolution.
    Matched MeSH terms: Mycobacterium tuberculosis/genetics*
  18. Tan JL, Nordin S, Besari AM
    Malays J Med Sci, 2017 Oct;24(5):119-123.
    PMID: 29386980 MyJurnal DOI: 10.21315/mjms2017.24.5.14
    Introduction: Tuberculosis is the second leading cause of death under the category of infectious diseases, after the human immunodeficiency virus (HIV). Tuberculous meningitis (TBM) constitutes about 5% of all extrapulmonary disease worldwide. This report describes a case of Tuberculous meningitis with rare presentation in a 28-year-old woman, who was treated based on a collection of her social background, clinical findings and Multiplex PCR of tuberculosis.

    Case presentation: A 28-year-old Malay woman with no significant medical history presented to HUSM with one month history of on and off fever, two weeks history of generalised limbs weakness and one week history of dysphagia. She was reported to have experienced visual hallucination and significant weight loss. Her laboratory result is significant for leukocytosis, elevated ESR and hypernatremia. Non-enhanced and contrast CT scan of the brain showed severe bilateral frontal cerebral atrophy. Cerebral spinal fluid (CSF) for multiplex PCR for Mycobacterium tuberculosis complex was positive. She was promptly started on anti-TB regime combined with dexamethasone. Subsequent follow-up showed significant improvement.

    Conclusion: This is a rare clinical manifestation of Tuberculous meningitis that demonstrates the importance of recognising and initiating the treatment early to reduce disabilities and improve clinical outcome.

    Matched MeSH terms: Mycobacterium tuberculosis
  19. Suresh Kumar
    MyJurnal
    Introduction: Tuberculosis (TB) is one of the utmost serious infectious diseases worldwide. The emergence of multi- drug resistance demands the development of better or new putative drug targets for tuberculosis. Recent studies sug- gest Mycobacterium tuberculosis cytochrome P450 enzymes as promising drug targets and azole drugs as potential inhibitors. Methods: Various computational tools, like Expasy Protparam, Swiss model, RaptorX and Phyre2 were used to analyze 12 Mycobacterium tuberculosis P450 enzymes and determine their three-dimensional structure. The structural validation was done through a Ramachandran plot using RAMPAGE server. The docking of P450 enzymes with azole drugs was done with autodock ver 4.2.6. Results: Based on sub-cellular localization prediction using CEL- LO tool, P450 enzymes CYP123A1, CYP132A1, CYP135A1, CYP136A1, CYP140A1, and CYP143A1 were predicted to be in the cytoplasm. Through structure assessment by Ramachandran plot, the best homology modelled proteins were docked with azole drugs like clotrimazole, croconazole, econazole, fluconazole, itraconazole, itraconazole, ketaconazole and micronazole by using autodock. By docking method it is identified that ketaconazole drug has a high affinity towards most of the mycobacterium P450 enzymes followed by the itrconazole drug. CYP123A1 enzyme is preferable as a drug target due to high binding affinity towards ketoconazole followed by CYP135A1, CYP140A1 enzymes. Conclusion: This study would help in identifying putative novel drug targets in Mycobacterium tuberculosis, which can lead to promising candidates for the optimization and development of novel anti-mycobac- terial agents.
    Matched MeSH terms: Mycobacterium tuberculosis
  20. Suraiya S, Semail N, Ismail MF, Abdullah JM
    Genome Announc, 2016;4(3).
    PMID: 27198011 DOI: 10.1128/genomeA.00323-16
    Mycobacterium tuberculosis is known to cause pulmonary and extrapulmonary tuberculosis. This organism showed special phylogeographical specificity. Here, we report the complete genome sequence of M. tuberculosis clinical isolate spoligotype SIT745/EAI1-MYS, which was isolated from a Malaysian tuberculosis patient.
    Matched MeSH terms: Mycobacterium tuberculosis
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links