scholarly journals Interplay Between the Phenotype and Genotype, and Efflux Pumps in Drug-Resistant Strains of Riemerella anatipestifer

2018 ◽  
Vol 9 ◽  
Author(s):  
Qiwei Chen ◽  
Xiaowei Gong ◽  
Fuying Zheng ◽  
Guo Ji ◽  
Shengdou Li ◽  
...  
2017 ◽  
Author(s):  
Privita Verma ◽  
Vishvanath Tiwari

Bacterial efflux pumps have emerged as antibiotic resistance determinants and confers multidrug resistance to a broad range of antimicrobials as well as non-antibiotic substances by potentially extruding them out. These are also associated with the virulence and biofilm formation. Thus, development of inhibitors against these effective antibacterial targets can be a highly beneficial approach in order to reverse the multidrug resistance (MDR) in the clinical relevant strains. A keen study on the efflux of foregoing or commonly used antibiotics will contribute in finding substrates that could bind efficiently with these efflux pumps. In the present study, we have explored efflux pumps belonging to Resistance-Nodulation-Division (RND) family as they are found prevalent in gram negative pathogens such as A. baumannii. The two RND efflux pumps under consideration are AdeABC and AcrAB-TolC. For comparative analysis, a non-RND family efflux pump i.e. NorM is selected here. We employed a series of computational techniques ranging from molecular docking to binding free energy estimation and molecular dynamics simulations to determine the binding affinity for different classess of drugs namely aminoglycosides, polymyxins, β-lactams, tetracyclines, glycylcyclines, quinolones and metronidazole against the efflux pumps under study. Our results revealed that class polymyxins has the highest binding affinity with the RND efflux pumps i.e. AcrAB-TolC and AdeABC as well as non-RND efflux pump (NorM). The experimental data was found to much extent in accordance with the binding free energy scores obtained from our in silico analysis. To recapitulate the outcome, polymyxins can possibly be the most efficient substrate for both RND and non-RND efflux pumps, thus, can be used as a reference drug for designing potent efflux pump inhibitors against multi-drug resistant strains.


2017 ◽  
Author(s):  
Privita Verma ◽  
Vishvanath Tiwari

Bacterial efflux pumps have emerged as antibiotic resistance determinants and confers multidrug resistance to a broad range of antimicrobials as well as non-antibiotic substances by potentially extruding them out. These are also associated with the virulence and biofilm formation. Thus, development of inhibitors against these effective antibacterial targets can be a highly beneficial approach in order to reverse the multidrug resistance (MDR) in the clinical relevant strains. A keen study on the efflux of foregoing or commonly used antibiotics will contribute in finding substrates that could bind efficiently with these efflux pumps. In the present study, we have explored efflux pumps belonging to Resistance-Nodulation-Division (RND) family as they are found prevalent in gram negative pathogens such as A. baumannii. The two RND efflux pumps under consideration are AdeABC and AcrAB-TolC. For comparative analysis, a non-RND family efflux pump i.e. NorM is selected here. We employed a series of computational techniques ranging from molecular docking to binding free energy estimation and molecular dynamics simulations to determine the binding affinity for different classess of drugs namely aminoglycosides, polymyxins, β-lactams, tetracyclines, glycylcyclines, quinolones and metronidazole against the efflux pumps under study. Our results revealed that class polymyxins has the highest binding affinity with the RND efflux pumps i.e. AcrAB-TolC and AdeABC as well as non-RND efflux pump (NorM). The experimental data was found to much extent in accordance with the binding free energy scores obtained from our in silico analysis. To recapitulate the outcome, polymyxins can possibly be the most efficient substrate for both RND and non-RND efflux pumps, thus, can be used as a reference drug for designing potent efflux pump inhibitors against multi-drug resistant strains.


2011 ◽  
Vol 100 (3) ◽  
pp. 831-835 ◽  
Author(s):  
Alisha K. Weight ◽  
Jayanta Haldar ◽  
Luis Álvarez de Cienfuegos ◽  
Larisa V. Gubareva ◽  
Terrence M. Tumpey ◽  
...  

The Lancet ◽  
1981 ◽  
Vol 317 (8216) ◽  
pp. 386
Author(s):  
Brian Darlow ◽  
Helena Vrbova ◽  
John Stace ◽  
Peter Heywood ◽  
Michael Alpers

2008 ◽  
Vol 20 (6) ◽  
pp. 761-763 ◽  
Author(s):  
D. Blanquer ◽  
J. De Otero ◽  
E. Padilla ◽  
F. Gòmez ◽  
A. Mayol ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
pp. 16-26
Author(s):  
Kimberly To ◽  
Ruoqiong Cao ◽  
Aram Yegiazaryan ◽  
James Owens ◽  
Kayvan Sasaninia ◽  
...  

Abstract Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) still remains a devastating infectious disease in the world. There has been a daunting increase in the incidence of Type 2 Diabetes Mellitus (T2DM) worldwide. T2DM patients are three times more vulnerable to M. tb infection compared to healthy individuals. TB-T2DM coincidence is a challenge for global health control. Despite some progress in the research, M. tb still has unexplored characteristics in successfully evading host defenses. The lengthy duration of treatment, the emergence of multi-drug-resistant strains and extensive-drug-resistant strains of M. tb have made TB treatment very challenging. Previously, we have tested the antimycobacterial effects of everolimus within in vitro granulomas generated from immune cells derived from peripheral blood of healthy subjects. However, the effectiveness of everolimus treatment against mycobacterial infection in individuals with T2DM is unknown. Furthermore, the effectiveness of the combination of in vivo glutathione (GSH) supplementation in individuals with T2DM along with in vitro treatment of isolated immune cells with everolimus against mycobacterial infection has never been tested. Therefore, we postulated that liposomal glutathione (L-GSH) and everolimus would offer great hope for developing adjunctive therapy for mycobacterial infection. L-GSH or placebo was administered to T2DM individuals orally for three months. Study subjects’ blood was drawn pre- and post-L-GSH/or placebo supplementation, where Peripheral Blood Mononuclear Cells (PBMCs) were isolated from whole blood to conduct in vitro studies with everolimus. We found that in vitro treatment with everolimus, an mTOR (membrane target of rapamycin) inhibitor, significantly reduced intracellular M. bovis BCG infection alone and in conjunction with L-GSH supplementation. Furthermore, we found L-GSH supplementation coupled with in vitro everolimus treatment produced a greater effect in inhibiting the growth of intracellular Mycobacterium bovis BCG, than with the everolimus treatment alone. We also demonstrated the functions of L-GSH along with in vitro everolimus treatment in modulating the levels of cytokines such as IFN-γ, TNF-α, and IL-2 and IL-6, in favor of improving control of the mycobacterial infection. In summary, in vitro everolimus-treatment alone and in combination with oral L-GSH supplementation for three months in individuals with T2DM, was able to increase the levels of T-helper type 1 (Th1) cytokines IFN-γ, TNF-α, and IL-2 as well as enhance the abilities of granulomas from individuals with T2DM to improve control of a mycobacterial infection.


Nanomedicine ◽  
2021 ◽  
Author(s):  
Pragya Prasanna ◽  
Prakash Kumar ◽  
Saptarshi Mandal ◽  
Tanvi Payal ◽  
Saurabh Kumar ◽  
...  

Aim: To analyze the efficacy and possible mechanism of action of 7,8-dihydroxyflavone (DHF) and DHF synthesized gold nanoparticles (GNPs) against the parasite Leishmania donovani. Methods: GNPs were synthesized using DHF and characterized by dynamic light scattering, ζ potential, Fourier transform infrared spectroscopy, transmission electron microscopy and x-ray diffraction. The efficacy of DHF and DHF-GNP were tested against sensitive and drug-resistant parasites. GNP uptake was measured on macrophages by atomic absorption spectroscopy. Results: DHF and DHF-GNP (∼35 nm) were equally effective against sensitive and drug-resistant strains and inhibited the arginase activity of parasites. Increased IFN-γ and reduced IL-12 cytokine response showed a Th1/Th2-mediated cell death in macrophages. Conclusion: The low cytotoxicity and high biological activity of DHF-GNP may be useful for chemotherapy of leishmaniasis.


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