scholarly journals Carvacrol exhibits rapid bactericidal activity against Streptococcus pyogenes through cell membrane damage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niluni M. Wijesundara ◽  
Song F. Lee ◽  
Zhenyu Cheng ◽  
Ross Davidson ◽  
H. P. Vasantha Rupasinghe
Keyword(s):  
Cell Membrane ◽  
Streptococcus Pyogenes ◽  
Bactericidal Activity ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Streptococcal Pharyngitis ◽  
Cell Membrane Integrity ◽  
Cell Membrane Damage ◽  
Antibiotic Development

AbstractStreptococcus pyogenes is an important human pathogen worldwide. The identification of natural antibacterial phytochemicals has renewed interest due to the current scarcity of antibiotic development. Carvacrol is a monoterpenoid found in herbs. We evaluated carvacrol alone and combined with selected antibiotics against four strains of S. pyogenes in vitro. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of carvacrol against S. pyogenes were 125 µg/mL (0.53 mM) and 250 µg/mL (1.05 mM), respectively. Kill curve results showed that carvacrol exhibits instantaneous bactericidal activity against S. pyogenes. We also demonstrated the potential mechanism of action of carvacrol through compromising the cell membrane integrity. Carvacrol induced membrane integrity changes leading to leakage of cytoplasmic content such as lactate dehydrogenase enzymes and nucleic acids. We further confirmed dose-dependent rupturing of cells and cell deaths using transmission electron microscopy. The chequerboard assay results showed that carvacrol possesses an additive-synergistic effect with clindamycin or penicillin. Carvacrol alone, combined with clindamycin or penicillin, can be used as a safe and efficacious natural health product for managing streptococcal pharyngitis.

scholarly journals New Functionalized Macroparticles for Environmentally Sustainable Biofilm Control in Water Systems

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 399
Author(s):  
Ana C. Barros ◽  
Ana Pereira ◽  
Luis F. Melo ◽  
Juliana P. S. Sousa
Keyword(s):  
Cell Membrane ◽  
Antimicrobial Agents ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Membrane System ◽  
Bacterial Cells ◽  
Cell Membrane Integrity ◽  
Cell Membrane Damage ◽  
Environmentally Sustainable ◽  
Partial Blocking

Reverse osmosis (RO) depends on biocidal agents to control the operating costs associated to biofouling, although this implies the discharge of undesired chemicals into the aquatic environment. Therefore, a system providing pre-treated water free of biocides arises as an interesting solution to minimize the discharge of chemicals while enhancing RO filtration performance by inactivating bacteria that could form biofilms on the membrane system. This work proposes a pretreatment approach based on the immobilization of an industrially used antimicrobial agent (benzalkonium chloride—BAC) into millimetric aluminum oxide particles with prior surface activation with DA—dopamine. The antimicrobial efficacy of the functionalized particles was assessed against Escherichia coli planktonic cells through culturability and cell membrane integrity analysis. The results showed total inactivation of bacterial cells within five min for the highest particle concentration and 100% of cell membrane damage after 15 min for all concentrations. When reusing the same particles, a higher contact time was needed to reach the total inactivation, possibly due to partial blocking of immobilized biocide by dead bacteria adhering to the particles and to the residual leaching of biocide. The overall results support the use of Al2O3-DA-BAC particles as antimicrobial agents for sustainable biocidal applications in continuous water treatment systems.

scholarly journals Decreased life span and membrane damage of carbamylated erythrocytes in vitro

Blood ◽  
1976 ◽  
Vol 47 (6) ◽  
pp. 909-917 ◽  
Author(s):  
TA Lane ◽  
ER Burka
Keyword(s):  
Cell Membrane ◽  
Life Span ◽  
Membrane Damage ◽  
Membrane Lipid ◽  
Red Cell ◽  
Significant Modification ◽  
Red Cell Membrane ◽  
Cell Membrane Damage ◽  
Sickle Erythrocytes

Abstract Red blood cells exposed to cyanate (CNO) in vitro have a concentration- dependent decreased cell survival time associated with an inhibition of the ability of the cell membrane to synthesize lipids. The t1/2 of rabbit erythrocytes exposed to 30 mM or 50 mM cyanate for 1 hr at 37 degrees C is reduced from the normal 24 days to 15 and 9 days, respectively. The cyanate-induced defect in membrane lipid metabolism is irreversible. Carbamylation of membrane proteins and damage to metabolism are minimized by limiting exposure in vitro to 15 mM cyanate at 4 degrees C for 30 min. Cells carbamylated under these conditions do not have a shortened life span. Levels of globin carbamylation of 0.5 moles CNO/mole hemoglobin, shown to be clinically effective in prolonging the life span of sickle erythrocytes, are obtained under these conditions and reach maximal levels after only 30 min of incubation. Carbamylation of blood in CPD anticoagulant is inferior to either ACD or heparin. The findings indicate that adequate carbamylation of sickle erythrocytes with minimal red cell membrane damage can be achieved without significant modification of the standard plasmapheresis procedure utilized by the working blood bank.

Assessment of changes in sperm cell membrane integrity occurring during the storage of semen from genetically different males using two diagnostic methods

2014 ◽  
Vol 94 (4) ◽  
pp. 601-606 ◽  
Author(s):  
Anna Wysokińska ◽  
Stanislaw Kondracki
Keyword(s):  
Cell Membrane ◽  
Sperm Cell ◽  
Cell Membranes ◽  
Intact Cell ◽  
Membrane Integrity ◽  
Diagnostic Methods ◽  
Cell Membrane Integrity ◽  
Staining Methods ◽  
Breed Crosses

Wysokińska, A. and Kondracki, S. 2014. Assessment of changes in sperm cell membrane integrity occurring during the storage of semen from genetically different males using two diagnostic methods. Can. J. Anim. Sci. 94: 601–606. The present study was carried out to assess changes in sperm cell membrane integrity occurring during the storage of semen collected from genetically different domestic male pigs. The study was aimed at assessing differences in the course of changes in the integrity of cell membranes in spermatozoa produced by males with different degrees of genetic diversity (pure-bred males, two-breed hybrids and multi-breed crosses) and testing the usefulness of two methods of sperm cell membrane integrity evaluation, based on material collected from genetically different males. The experiments were conducted on 56 ejaculates collected from 28 domestic male pigs. The examination of sperm cell membrane integrity was performed three times for each ejaculate, i.e., after 1 h, after 24 h and after 48 h from collection. The preparations for analysing cell membrane integrity were made using two methods: the SYBR 14/PI method and the eosin–nigrosin method. It was found that both SYBR 14/PI and eosin–nigrosin staining methods make it possible to successfully assess the integrity of the plasma membrane of domestic pig sperm cells under in vitro conditions. Hybrid pig spermatozoa, especially those from multi-breed crosses, better retain the integrity of their plasmalemmas than the spermatozoa of pure-bred boars. The ejaculates of Hypor cross-breed boars assessed after 1, 24 and 48 h of storage contain more spermatozoa with intact cell membranes than the ejaculates of pure-bred Duroc and Pietrain boars. The ejaculates of Hypor boars also show fewer decaying spermatozoa than those produced by pure-bred boars.

scholarly journals Decreased life span and membrane damage of carbamylated erythrocytes in vitro

Blood ◽  
1976 ◽  
Vol 47 (6) ◽  
pp. 909-917
Author(s):  
TA Lane ◽  
ER Burka
Keyword(s):  
Cell Membrane ◽  
Life Span ◽  
Membrane Damage ◽  
Membrane Lipid ◽  
Red Cell ◽  
Significant Modification ◽  
Red Cell Membrane ◽  
Cell Membrane Damage ◽  
Sickle Erythrocytes

Red blood cells exposed to cyanate (CNO) in vitro have a concentration- dependent decreased cell survival time associated with an inhibition of the ability of the cell membrane to synthesize lipids. The t1/2 of rabbit erythrocytes exposed to 30 mM or 50 mM cyanate for 1 hr at 37 degrees C is reduced from the normal 24 days to 15 and 9 days, respectively. The cyanate-induced defect in membrane lipid metabolism is irreversible. Carbamylation of membrane proteins and damage to metabolism are minimized by limiting exposure in vitro to 15 mM cyanate at 4 degrees C for 30 min. Cells carbamylated under these conditions do not have a shortened life span. Levels of globin carbamylation of 0.5 moles CNO/mole hemoglobin, shown to be clinically effective in prolonging the life span of sickle erythrocytes, are obtained under these conditions and reach maximal levels after only 30 min of incubation. Carbamylation of blood in CPD anticoagulant is inferior to either ACD or heparin. The findings indicate that adequate carbamylation of sickle erythrocytes with minimal red cell membrane damage can be achieved without significant modification of the standard plasmapheresis procedure utilized by the working blood bank.

Abstract 8: GTPase-Activating Protein for Rho Associated with FAK (GRAF) Regulates Cardiomyocyte Membrane Integrity

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Thomas J O'Neill ◽  
Kaitlin Lenhart ◽  
Jason Doherty ◽  
Mauricio Rojas ◽  
Mack P Christopher ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Muscle Pathology ◽  
Blue Dye ◽  
Membrane Repair ◽  
Cell Membrane Damage ◽  
Deficient Mice

Cardiac myocytes are unique in their requirement to sustain continuous repetitive contraction in the setting of intense mechanical stress while simultaneously maintaining high membrane integrity for an appropriate electrical gradient. The consequence of failure of the membrane repair response has been highlighted in recent reports linking cardiomyocyte membrane fragility with cardiac degeneration in patients as well as in their analogous mouse models. Herein, we describe a novel role for GTPase activator for Rho associated with Focal Adhesion Kinase (GRAF) in regulating cardiomyocyte membrane integrity. We previously published that disruption of GRAF in Xenopus laevis resulted in progressive skeletal muscle degeneration. We now show that GRAF-depleted tadpoles exhibit defective cardiac formation and function. Interestingly, damage of muscle cells in vivo and in vitro led to a translocation of GRAF to the sarcolemma, suggesting that GRAF may be an important component of the cardiac membrane repair machinery. To further explore this possibility, we generated GRAF hypomorphic mice that exhibit greater than 99% reduction of endogenous GRAF expression. While GRAF deficient mice show normal Mendelian birth distribution and are viable, they exhibit a modest skeletal muscle pathology. Although baseline cardiac integrity was not compromised in GRAF deficient mice, treatment either with cardiotoxin or intraperitoneal injection of isoproterenol led to elevated cardiomyocyte membrane damage (assessed by Evan’s blue dye uptake) in GRAF deficient compared to control mice (19% vs 2% of myocytes within afflicted ventricular area for cardiotoxin, 18% vs 8% for isoproterenol respectively). Moreover, cultured GRAF null myocytes exhibited a significantly attenuated membrane resealing response following laser-mediated disruption compared to GRAF-containing control cells as assessed by accumulation of the membrane impermeable dye, FM-143. As well, the survival rate after injury of GRAF-deficient cells was markedly attenuated (20% vs 85% in control cells). While cardiac cell membrane damage is likely a frequent and important event, the repair process is currently understudied, and this is the first report to implicate a Rho regulator in this response.

scholarly journals Altering the Proclivity towards Daptomycin Resistance in Methicillin-Resistant Staphylococcus aureus Using Combinations with Other Antibiotics

2012 ◽  
Vol 56 (10) ◽  
pp. 5046-5053 ◽  
Author(s):  
Andrew D. Berti ◽  
Justine E. Wergin ◽  
Gary G. Girdaukas ◽  
Scott J. Hetzel ◽  
George Sakoulas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Membrane ◽  
Membrane Integrity ◽  
Wall Thickening ◽  
Methicillin Resistant ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Cell Membrane Fluidity

ABSTRACTDaptomycin (DAP) is increasingly used as a part of combination therapy, particularly in complex methicillin-resistantStaphylococcus aureus(MRSA) infections. While multiple studies have reported the potential for synergy between DAP and adjunctive anti-infectives, few have examined the influence of adjunctive therapy on the emergence of DAP resistance. This study examined eight adjunctive antimicrobial combinations with DAPin vitroand the emergence of DAP resistance over time (up to 4 weeks) using clinical isolates of DAP-susceptible MRSA (MIC, 0.5 μg/ml) in which DAP resistance subsequently developed during patient therapy (MIC, 3 μg/ml). In addition to DAP susceptibility testing, selected strains were examined for phenotypic changes associated with DAP resistance, including changes to cell wall thickness (CWT) and cell membrane alterations. The addition of either oxacillin or clarithromycin in medium containing DAP significantly inhibited the development of DAP resistance through the entirety of the 4-week exposure (10- to 32-fold MIC reduction from that of DAP alone). Combinations with rifampin or fosfomycin were effective in delaying the emergence of DAP resistance through the end of week one only (week one MIC, 0.5 μg/ml; week four MIC, 24 μg/ml). Cell wall thickening was observed for all antibiotic combinations regardless of their effect on the DAP MIC (14 to 70% increase in CWT), while changes in cell membrane fluidity were variable and treatment dependent. DAP showed reduced activity against strains with DAP MICs of 1 to 12 μg/ml, but cell membrane integrity was still disrupted at concentrations achieved with doses greater than 10 mg/kg of body weight. The emergence of DAP resistance in MRSA is strongly influenced by the presence of subinhibitory concentrations of adjunctive antimicrobials. These data suggest that combining DAP with oxacillin or clarithromycin may delay the development of DAP resistance in cases requiring prolonged antibiotic therapy.

scholarly journals Red blood cell membrane integrity in primary open angle glaucoma: ex vivo and in vitro studies

Eye ◽  
1999 ◽  
Vol 13 (1) ◽  
pp. 101-103 ◽  
Author(s):  
L Zabala ◽  
C Saldanha ◽  
J Martins E Silva ◽  
P Souza-Ramalho
Keyword(s):  
Cell Membrane ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Primary Open Angle Glaucoma ◽  
Ex Vivo ◽  
Open Angle Glaucoma ◽  
Membrane Integrity ◽  
Open Angle ◽  
Cell Membrane Integrity

Protective effect of diosmetin on in vitro cell membrane damage and oxidative stress in cultured rat hepatocytes

Toxicology ◽  
1992 ◽  
Vol 73 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Pia Villa ◽  
Dario Cova ◽  
Laura De Francesco ◽  
Amalia Guaitani ◽  
Giuseppina Palladini ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Membrane ◽  
Protective Effect ◽  
Membrane Damage ◽  
Rat Hepatocytes ◽  
Cell Membrane Damage ◽  
Cultured Rat Hepatocytes ◽  
And Oxidative Stress

Effects of benzene, a water soluble component of crude oils, on membrane integrity and ionic content of the green alga Ankistrodesmus falcatus var. mirabilis

1978 ◽  
Vol 13 (1) ◽  
pp. 85-95 ◽  
Author(s):  
P. B. Kauss ◽  
T. C. Hutchinson
Keyword(s):  
Cell Membrane ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Water Soluble ◽  
Membrane Disruption ◽  
Time Intervals ◽  
Ionic Content ◽  
Cell Membrane Damage ◽  
Ankistrodesmus Falcatus ◽  
Cell Membrane Disruption

Abstract Experiments were devised to investigate the effects of the aromatic hydrocarbon benzene on the membrane integrity of the green freshwater alga Ankistrodesmus falcatus var. mirabilis. The ability of cells to retain ions (e.g. calcium, chlorine, copper, magnesium, manganese and potassium) when exposed to benzene was used as a measure of cell membrane disruption. Cells were exposed to various dosages of benzene in the light and the dark. Samples removed at pre-determined time intervals were analyzed for the above elements using neutron activation analysis. It was found that, (at dosages greater than ~24 umoles benzene per μl−1 cell volume), the rate of loss of potassium and manganese was proportional to both the benzene dosage and the time of exposure, but not affected by illumination. However, although loss of potassium and manganese from cells was complete after 24h exposure to the highest benzene dosage used (48 μmoles. μl−1) only a fraction of calcium, chlorine, copper and magnesium had been lost. This suggests a difference in the degree that these elements are bound or free in the cells, and that loss of potassium and manganese from cells is a sensitive indicator of cell membrane damage.

Sign in / Sign up

Export Citation Format

Share Document