In Silico Approach for Phytocompound-Based Drug Designing to Fight Efflux Pump-Mediated Multidrug-Resistant Mycobacterium tuberculosis

ABSTRACTThe 1,5-diarylpyrrole derivative BM212 was previously shown to be active against multidrug-resistant clinical isolates andMycobacterium tuberculosisresiding within macrophages as well as againstMycobacterium aviumand other atypical mycobacteria. To determine its mechanism of action, we identified the cellular target. SpontaneousMycobacterium smegmatis,Mycobacterium bovisBCG, andM. tuberculosisH37Rv mutants that were resistant to BM212 were isolated. By the screening of genomic libraries and by whole-genome sequencing, we found that all the characterized mutants showed mutations in themmpL3gene, allowing us to conclude that resistance to BM212 maps to the MmpL3 protein, a member of the MmpL (mycobacterialmembraneprotein,large) family. Susceptibility was unaffected by the efflux pump inhibitors reserpine, carbonylcyanidem-chlorophenylhydrazone, and verapamil. Uptake/efflux experiments with [14C]BM212 demonstrated that resistance is not driven by the efflux of BM212. Together, these data strongly suggest that the MmpL3 protein is the cellular target of BM212.

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Global Genome Comparative Analysis Reveals Insights of Resistome and Life-Style Adaptation ofPseudomonas putidaStrain T2-2 in Oral Cavity

The Scientific World JOURNAL ◽

10.1155/2014/930727 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Xin Yue Chan ◽

Kah Ooi Chua ◽

Kah Yan How ◽

Wai-Fong Yin ◽

Kok-Gan Chan

Keyword(s):

Drug Resistance ◽

Oral Cavity ◽

Genome Analysis ◽

In Silico ◽

Efflux Pump ◽

Multidrug Resistant ◽

Whole Genome Analysis ◽

Resistance Profile ◽

Wide Range ◽

Drug Resistance Profile

MostPseudomonas putidastrains are environmental microorganisms exhibiting a wide range of metabolic capability but certain strains have been reported as rare opportunistic pathogens and some emerged as multidrug resistantP. putida. This study aimed to assess the drug resistance profile of, via whole genome analysis,P. putidastrain T2-2 isolated from oral cavity. At the same time, we also compared the nonenvironmental strain with environmentally isolatedP. putida.In silicocomparative genome analysis with available reference strains ofP. putidashows that T2-2 has lesser gene counts on carbohydrate and aromatic compounds metabolisms, which suggested its little versatility. The detection of itseddgene also suggested T2-2’s catabolism of glucose via ED pathway instead of EMP pathway. On the other hand, its drug resistance profile was observed viain silicogene prediction and most of the genes found were in agreement with drug-susceptibility testing in laboratory by automated VITEK 2. In addition, the finding of putative genes of multidrug resistance efflux pump and ATP-binding cassette transporters in this strain suggests a multidrug resistant phenotype. In summary, it is believed that multiple metabolic characteristics and drug resistance inP. putidastrain T2-2 helped in its survival in human oral cavity.

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Mutations inpepQConfer Low-Level Resistance to Bedaquiline and Clofazimine in Mycobacterium tuberculosis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00753-16 ◽

2016 ◽

Vol 60 (8) ◽

pp. 4590-4599 ◽

Cited By ~ 84

Author(s):

Deepak Almeida ◽

Thomas Ioerger ◽

Sandeep Tyagi ◽

Si-Yang Li ◽

Khisimuzi Mdluli ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Efflux Pump ◽

Multidrug Resistant ◽

Cross Resistance ◽

Loss Of Function ◽

Content Type ◽

Low Level ◽

Resistant Tuberculosis ◽

Multidrug Resistant Tuberculosis

ABSTRACTThe novel ATP synthase inhibitor bedaquiline recently received accelerated approval for treatment of multidrug-resistant tuberculosis and is currently being studied as a component of novel treatment-shortening regimens for drug-susceptible and multidrug-resistant tuberculosis. In a limited number of bedaquiline-treated patients reported to date, ≥4-fold upward shifts in bedaquiline MIC during treatment have been attributed to non-target-based mutations inRv0678that putatively increase bedaquiline efflux through the MmpS5-MmpL5 pump. These mutations also confer low-level clofazimine resistance, presumably by a similar mechanism. Here, we describe a new non-target-based determinant of low-level bedaquiline and clofazimine cross-resistance inMycobacterium tuberculosis: loss-of-function mutations inpepQ(Rv2535c), which corresponds to a putative Xaa-Pro aminopeptidase.pepQmutants were selected in mice by treatment with clinically relevant doses of bedaquiline, with or without clofazimine, and were shown to have bedaquiline and clofazimine MICs 4 times higher than those for the parental H37Rv strain. Coincubation with efflux inhibitors verapamil and reserpine lowered bedaquiline MICs against both mutant and parent strains to a level below the MIC against H37Rv in the absence of efflux pump inhibitors. However, quantitative PCR (qPCR) revealed no significant differences in expression ofRv0678,mmpS5, ormmpL5between mutant and parent strains. Complementation of apepQmutant with the wild-type gene restored susceptibility, indicating that loss of PepQ function is sufficient for reduced susceptibility bothin vitroand in mice. Although the mechanism by which mutations inpepQconfer bedaquiline and clofazimine cross-resistance remains unclear, these results may have clinical implications and warrant further evaluation of clinical isolates with reduced susceptibility to either drug for mutations in this gene.

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Expression analysis of efflux pump genes among drug-susceptible and multidrug-resistant Mycobacterium tuberculosis clinical isolates and reference strains

Diagnostic Microbiology and Infectious Disease ◽

10.1016/j.diagmicrobio.2013.02.033 ◽

2013 ◽

Vol 76 (3) ◽

pp. 291-297 ◽

Cited By ~ 17

Author(s):

Mustafa Kerem Calgin ◽

Fikret Sahin ◽

Buse Turegun ◽

Devran Gerceker ◽

Melike Atasever ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Expression Analysis ◽

Efflux Pump ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Reference Strains

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Identification of new efflux pump proteins from multidrug resistant Mycobacterium tuberculosis and screening for peptide based efflux pump inhibitors

International Journal of Infectious Diseases ◽

10.1016/j.ijid.2016.02.864 ◽

2016 ◽

Vol 45 ◽

pp. 404-405

Author(s):

K. Parthasarathy ◽

A. Sivaraj ◽

R. Sundar

Keyword(s):

Mycobacterium Tuberculosis ◽

Efflux Pump ◽

Multidrug Resistant ◽

Efflux Pump Inhibitors

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Discovery of natural inhibitors targeting 2 - trans enoyl acyl carrier protein reductase in Mycobacterium tuberculosis by structure based drug designing

Annals of Plant Sciences ◽

10.21746/aps.2016.09.002 ◽

2016 ◽

Vol 5 (09) ◽

pp. 1417 ◽

Cited By ~ 1

Author(s):

Saurov Mahanta ◽

Purvita Chowdhury ◽

Shamsun Nahar ◽

Bhaben Tanti ◽

P. J. Handique*

Keyword(s):

Mycobacterium Tuberculosis ◽

Acyl Carrier Protein ◽

Multidrug Resistant ◽

Carrier Protein ◽

Lipinski’S Rule ◽

Lead Compounds ◽

Experimental Drug ◽

Rapid Spread ◽

Drug Designing ◽

Acid Pathway

Evolution and the rapid spread of the multidrug resistant Mycobacterium tuberculosis (Mtb) have posed a serious crisis. Moreover, the available first line drugs also confer adverse effects on the patients suffering from tuberculosis (TB) thus making the cure increasingly difficult. Thus the search of novel and potent natural compounds targeting anti-tubercular agents has become inevitable. Here, we report identification of potential natural anti-tubercular candidates targeting Mtb 2-Trans Enoyl Acyl Carrier Protein Reductase (InhA) of the fatty acid pathway using structure based drug designing. In the present study, we selected a total of 154 compounds from three plants i.e. Ginkgo biloba, Neem (Azadirachta indica) and Tea (Camellia sinensis) which were obtained from PubChem Compounds. These compounds were subjected to Lipinski’s rule of five and drug likeness filters. Finally, the compounds were docked at the active site of Mtb InhA (PDB code: 3FNE) using AutoDock Vina to select inhibitors with favourable interactions. The structure based ligand receptor docking aided in the identification of a number of natural candidates which had high binding affinities against Mtb InhA. Thus, these molecules could potentially inhibit Mtb InhA and succor to the development of lead compounds in the experimental drug discovery of anti-tuberculars.

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