Objective:To investigate the mechanism of antibacterial activity of luteoiin(LUT) against methicillin-resistant Staphylococcus aureus(MRSA).Methods:The mechanism of anti-MRSA activity of LUT was analyzed by the viabil...Objective:To investigate the mechanism of antibacterial activity of luteoiin(LUT) against methicillin-resistant Staphylococcus aureus(MRSA).Methods:The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent ATPase inhibitors,and peptidoglycan(PGN) derived from Staphylococcus aureus(S.aureus).Also,transmission electron microscopy was used to monitor survival characteristics and changes in S.aureus morphology.Results:Compared to the LUT alone,the optical density of suspensions treated with the combination of 125 μg/mL Tris and 230 μg/mL DCCD were reduced to 60%and 46%,respectively.PGN(15.6 μg/mL) gradually impeded the activity of LUT,and PGN(62.5 μg/mL) completely blocked the activity of LUT on S.aureus.Conclusions:Increased susceptibility to LUT with me Tris and DCCD combinations is evident in all tested MRSA isolates.The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase.S.aureus PGN directly blocks the antibacterial activity of LUT,suggesting the direct binding of LUT with PGN.These findings may be validated for the development of antibacterial agent for low MRSA resistance.展开更多
Objective: To investigate the antibacterial activity of SHHextracted with either water or ethanol against methicillin-resistant Staphylococcus aureus(MRSA) and combinatory antimicrobial effect with ciprofloxacin(CIP) ...Objective: To investigate the antibacterial activity of SHHextracted with either water or ethanol against methicillin-resistant Staphylococcus aureus(MRSA) and combinatory antimicrobial effect with ciprofloxacin(CIP) by time kill assay and checkerboard dilution test. Methods: The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of Sami-Hyanglyun-Hwan(SHH) water extract(SHHW) and SHH ethanol extract(SHHE) ranged from 250 to 2000 μg/m L and 125 to 1000 μg/m L against MRSA, respectively. Results: In the checkerboard method, the combinations of SHHE with CIP had a partial synergistic or synergistic effect against MRSA. The time-kill curves showed that a combined SHHE and CIP treatment reduced the bacterial counts dramatically after 24 h. Conclusions: The present study demonstrates the therapeutic ability of SHHE against MRSA infections.展开更多
Objective:To investigate the gene related to β-lactam resistance and to confirm the mechanism about a synergy effect between CPZ and β-lactam antibiotics.Methods:To measure antibacterial activity,we performed a mini...Objective:To investigate the gene related to β-lactam resistance and to confirm the mechanism about a synergy effect between CPZ and β-lactam antibiotics.Methods:To measure antibacterial activity,we performed a minimum inhibitory concentration(MIC) and synergy test.Transmission electron microscopy(TEM) was used in morphological analysis.To analyze gene expression,we conducted reverse transcriptase polymerase chain reaction(PCR).Results:We confirmed a synergy effect between CPZ and β-lactam antibiotics.Furthermore,we observed that CPZ affect the cell envelope of MRS A by using TEM.At the gene level,CPZ reduced the expression of resistance genes.Conclusions:Through this result,we hypothesize that a decrease of resistance factor expressions was caused by CPZ because it disrupts the activity of a sensor protein located in the cell membrane.展开更多
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Educatio(2013060380)+2 种基金the Korea governmen(MSIP)(2008-0062484)Cooperative Research Program for Agriculture Science&Technology Development(Project No.PJ00962201)Rural Development Administration,Republic of Korea
文摘Objective:To investigate the mechanism of antibacterial activity of luteoiin(LUT) against methicillin-resistant Staphylococcus aureus(MRSA).Methods:The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent ATPase inhibitors,and peptidoglycan(PGN) derived from Staphylococcus aureus(S.aureus).Also,transmission electron microscopy was used to monitor survival characteristics and changes in S.aureus morphology.Results:Compared to the LUT alone,the optical density of suspensions treated with the combination of 125 μg/mL Tris and 230 μg/mL DCCD were reduced to 60%and 46%,respectively.PGN(15.6 μg/mL) gradually impeded the activity of LUT,and PGN(62.5 μg/mL) completely blocked the activity of LUT on S.aureus.Conclusions:Increased susceptibility to LUT with me Tris and DCCD combinations is evident in all tested MRSA isolates.The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase.S.aureus PGN directly blocks the antibacterial activity of LUT,suggesting the direct binding of LUT with PGN.These findings may be validated for the development of antibacterial agent for low MRSA resistance.
文摘Objective: To investigate the antibacterial activity of SHHextracted with either water or ethanol against methicillin-resistant Staphylococcus aureus(MRSA) and combinatory antimicrobial effect with ciprofloxacin(CIP) by time kill assay and checkerboard dilution test. Methods: The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of Sami-Hyanglyun-Hwan(SHH) water extract(SHHW) and SHH ethanol extract(SHHE) ranged from 250 to 2000 μg/m L and 125 to 1000 μg/m L against MRSA, respectively. Results: In the checkerboard method, the combinations of SHHE with CIP had a partial synergistic or synergistic effect against MRSA. The time-kill curves showed that a combined SHHE and CIP treatment reduced the bacterial counts dramatically after 24 h. Conclusions: The present study demonstrates the therapeutic ability of SHHE against MRSA infections.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2012-0004337)
文摘Objective:To investigate the gene related to β-lactam resistance and to confirm the mechanism about a synergy effect between CPZ and β-lactam antibiotics.Methods:To measure antibacterial activity,we performed a minimum inhibitory concentration(MIC) and synergy test.Transmission electron microscopy(TEM) was used in morphological analysis.To analyze gene expression,we conducted reverse transcriptase polymerase chain reaction(PCR).Results:We confirmed a synergy effect between CPZ and β-lactam antibiotics.Furthermore,we observed that CPZ affect the cell envelope of MRS A by using TEM.At the gene level,CPZ reduced the expression of resistance genes.Conclusions:Through this result,we hypothesize that a decrease of resistance factor expressions was caused by CPZ because it disrupts the activity of a sensor protein located in the cell membrane.
基金Supported by the National Research Foundation of Korea Grant (No.NRF-2010-013-E00034)the Grant of the Traditional Korean Medicine R&D project,Ministry of Health & Welfare, Republic of Korea(No.B120069)
