scholarly journals Lipid Flip-Flop-Inducing Antimicrobial Phytochemicals from Gymnema sylvestre are Bacterial Membrane Permeability Enhancers

ACS Omega ◽  
2021 ◽  
Author(s):  
Himadri Gourav Behuria ◽  
Gandarvakottai Senthilkumar Arumugam ◽  
Chandan Kumar Pal ◽  
Ashis Kumar Jena ◽  
Santosh Kumar Sahu
Keyword(s):  
Membrane Permeability ◽  
Bacterial Membrane ◽  
Gymnema Sylvestre ◽  
Flip Flop ◽  
Permeability Enhancers

Tuning the Effects of Bacterial Membrane Permeability through Photo-Isomerization of Antimicrobial Cationic Amphiphiles

2017 ◽  
Vol 23 (52) ◽  
pp. 12724-12728 ◽  
Author(s):  
Joana Salta ◽  
Raphael I. Benhamou ◽  
Ido M. Herzog ◽  
Micha Fridman
Keyword(s):  
Membrane Permeability ◽  
Bacterial Membrane ◽  
Cationic Amphiphiles

scholarly journals Combinatorial Antimicrobial Efficacy and Mechanism of Linalool Against Clinically Relevant Klebsiella pneumoniae

2021 ◽  
Vol 12 ◽  
Author(s):  
Shun-Kai Yang ◽  
Khatijah Yusoff ◽  
Mokrish Ajat ◽  
Chien-Yeong Wee ◽  
Polly-Soo-Xi Yap ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Klebsiella Pneumoniae ◽  
Membrane Permeability ◽  
Membrane Damage ◽  
Bacterial Membrane ◽  
Bacterial Cells ◽  
Bacterial Killing ◽  
Potential Measurement ◽  
Bacterial Surface ◽  
Electron Microscopies

Antibiotic–adjuvant combinatory therapy serves as a viable treatment option in addressing antibiotic resistance in the clinical setting. This study was carried out to assess and characterize the adjuvant potential and mode of action of linalool against carbapenemase-producing Klebsiella pneumoniae (KPC-KP). Linalool exhibited bactericidal activity alone (11,250 μg/ml) and in combination with meropenem (5,625 μg/ml). Comparative proteomic analysis showed significant reduction in the number of cytoplasmic and membrane proteins, indicating membrane damage in linalool-treated KPC-KP cells. Upregulation of oxidative stress regulator proteins and downregulation of oxidative stress-sensitive proteins indicated oxidative stress. Zeta potential measurement and outer membrane permeability assay revealed that linalool increases the bacterial surface charge as well as the membrane permeability. Intracellular leakage of nucleic acid and proteins was detected upon linalool treatment. Scanning and transmission electron microscopies further revealed the breakage of bacterial membrane and loss of intracellular materials. Linalool induced oxidative stress by generating reactive oxygen species (ROS) which initiates lipid peroxidation, leading to damage of the bacterial membrane. This leads to intracellular leakage, eventually killing the KPC-KP cells. Our study demonstrated that linalool possesses great potential in future clinical applications as an adjuvant along with existing antibiotics attributed to their ability in disrupting the bacterial membrane by inducing oxidative stress. This facilitates the uptake of antibiotics into the bacterial cells, enhancing bacterial killing.

scholarly journals Study to elucidate effect of titanium dioxide nanoparticles on bacterial membrane potential and membrane permeability

2020 ◽  
Vol 7 (3) ◽  
pp. 035005 ◽  
Author(s):  
Maya S Khater ◽  
Gauri R Kulkarni ◽  
Sagar S Khater ◽  
Haribhau Gholap ◽  
Rajendra Patil
Keyword(s):  
Titanium Dioxide ◽  
Membrane Potential ◽  
Membrane Permeability ◽  
Titanium Dioxide Nanoparticles ◽  
Bacterial Membrane

scholarly journals Curcumin activation of a bacterial mechanosensitive channel underlies its membrane permeability and adjuvant properties

2021 ◽  
Vol 17 (12) ◽  
pp. e1010198
Author(s):  
Robin Wray ◽  
Irene Iscla ◽  
Paul Blount
Keyword(s):  
Membrane Permeability ◽  
Natural Compound ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Cell Lysis ◽  
Membrane Permeabilization ◽  
Mechanosensitive Channel ◽  
Bacterial Membrane ◽  
Physiological Effects ◽  
Membrane Tension

Curcumin, a natural compound isolated from the rhizome of turmeric, has been shown to have antibacterial properties. It has several physiological effects on bacteria including an apoptosis-like response involving RecA, membrane permeabilization, inhibiting septation, and it can also work synergistically with other antibiotics. The mechanism by which curcumin permeabilizes the bacterial membrane has been unclear. Most bacterial species contain a Mechanosensitive channel of large conductance, MscL, which serves the function of a biological emergency release valve; these large-pore channels open in response to membrane tension from osmotic shifts and, to avoid cell lysis, allow the release of solutes from the cytoplasm. Here we show that the MscL channel underlies the membrane permeabilization by curcumin as well as its synergistic properties with other antibiotics, by allowing access of antibiotics to the cytoplasm; MscL also appears to have an inhibitory role in septation, which is enhanced when activated by curcumin.

Bacterial membrane permeability of antimicrobial polymethacrylates: Evidence for a complex mechanism from super-resolution fluorescence imaging

2020 ◽  
Vol 108 ◽  
pp. 168-177 ◽  
Author(s):  
Thomas D. Michl ◽  
Ben Hibbs ◽  
Lauren Hyde ◽  
Almar Postma ◽  
Dung Thuy Thi Tran ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Fluorescence Imaging ◽  
Super Resolution ◽  
Bacterial Membrane ◽  
Complex Mechanism

scholarly journals Reversal of Polymicrobial Biofilm Tolerance to Ciprofloxacin by Blue Light plus Carvacrol

2021 ◽  
Vol 9 (10) ◽  
pp. 2074
Author(s):  
Yongli Li ◽  
Mei X. Wu
Keyword(s):  
Membrane Permeability ◽  
Blue Light ◽  
Chronic Wound ◽  
Membrane Damage ◽  
Bacterial Membrane ◽  
Wound Infections ◽  
Multispecies Biofilm ◽  
Chronic Wound Infections ◽  
Multispecies Biofilms ◽  
Dual Treatment

Chronic wound infections are often caused by multi-species biofilms and these biofilm-embedded bacteria exhibit remarkable tolerance to existing antibiotics, which presents huge challenges to control such infections in the wounds. In this investigation, we established a polymicrobial biofilm composed of P. aeruginosa, S. aureus, K. pneumoniae, and A. baumannii. We tested a cocktail therapy comprising 405-nm blue light (BL), carvacrol (Ca), and antibiotics on the multispecies biofilm. Despite the fact that all strains used to form the biofilm were susceptible to ciprofloxacin (CIP) in planktonic cultures, the biofilm was found to withstand ciprofloxacin as well as BL-Ca dual treatment, mainly because K. pneumoniae outgrew and became dominant in the biofilm after each treatment. Strikingly, when ciprofloxacin was combined with BL-Ca, the multispecies biofilms succumbed substantially and were eradicated at an efficacy of 99.9%. Mechanistically, BL-Ca treatment increased membrane permeability and potentiated the anti-biofilm activity of ciprofloxacin, probably by facilitating ciprofloxacin’s entrance of the bacteria, which is particularly significant for K. pneumoniae, a species that is refractory to either ciprofloxacin or BL-Ca dual treatment. The results suggest that bacterial membrane damage can be one of the pivotal strategies to subvert biofilm tolerance and combat the recalcitrant multispecies biofilms.

Initial Polymerization Sites Indicated During Mitochondrial Oxidation of Diaminobenzidine after Toluene Treatment

1977 ◽  
Vol 35 ◽  
pp. 408-409
Author(s):  
W. A. Shannon ◽  
M. A. Matlib
Keyword(s):  
Membrane Permeability ◽  
Cytochrome Oxidase ◽  
Rat Liver ◽  
Precise Definition ◽  
Cytochemical Localization ◽  
Oxidative Reaction ◽  
Mitochondrial Oxidation ◽  
Definition Of ◽  
Exogenous Substrates

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.

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