丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

丝光绿蝇抗菌物质在不同pH下抑菌活性的研究

Objective To investigate the antibacterial activity of antibacterial substance in Lucilia seri-cata induced by pricking the skin of maggots(fly s larvae)at different pH conditions. Methods The hemo-lymph from the third instar maggots was collected 48 h after pricking,and the antibacterial effect was tested a-gainst Micrococcus lysodeikticus and Staphylococcus aureus on plates at different pH conditions.The antibacterial effect against M.1ysodeikticus was also detected after the hemolymph、was diluted by different pH buffer solu-tions.The bacteriostatic effects were observed after 24 h and the diameters of clear inhibitory ring were recorded to express antibacterial activity. Results The antibacterial activity of the maggot hemolymph against M.lyso-deiktics and S.aureus was stronger on the plates at pH 6.0 and pH 6.5 than that on the other plates.In the group diluted by pH 6.0 buffer solutions.the antibacterial ring of the maggot hemolymph against M lysodeiktic-us was larger than that in others. Conclusion The results implied that the induced antibacterial substance in Lucilia sericata exhibited stronger antibacterial activity under acidic condition.     

Crude extract of maggots:Antibacterial effects against Escherichia coli,underlying mechanisms,separation and purification

AIM:To investigate the antibacterial effects of a crude extract of maggots against Escherichia coli(E.coli) and the underlying mechanisms,and to separate and purifythe crude extract of maggots to assess the antibacterial effects of the active ingredients in the crude extract.METHODS:Different concentrations of the crude extract of maggots were incubated with E.coli(O157:H7) and cultured.The optical density(OD) was measured at different time points to plot the OD-T curve.The effects of different concentrations of the crude extract on bacterial membrane permeability were determined by fluorescence probe technique.The effects of different concentrations of the crude extract on plasmid DNA replication were determined by agarose gel electrophoresis.DEAE-Sepharose ion exchange chromatography and Sephacryls-200 HR gel filtration chromatography were used to separate and purify the crude extract of maggots.The molecular weight of proteins in the purified crude extract was determined by SDS-PAGD electrophoresis,and its antibacterial effects were determined by turbidimetric method.RESULTS:The antibacterial effects of the crude extract of maggots at concentrations > 0.5 mg/m L were significant.The antibacterial effects of the crude extract at concentrations of 1.0,1.5 and 2.0 mg/m L did not differ significantly.Fluorescence probe analysis showed that the rate of membrane permeability change was 1223.1% in bacteria incubated with 2 mg/m L of the crude extract,and 1300.0% in those incubated with 80 mg/m L of the crude extract.Plasmid DNA was undetectable in E.coli incubated with 2 and 80 mg/m L of the crude extract.A low molecular weight protein band(about 15 k Da) was detected in the crude extract of maggots and eluent,but not in eluant,from DEAE-Sepharose ion exchange chromatography.The antibacterial effects of the crude extract of maggots and eluent were superior to those of eluant,with the antibacterial effects of eluents being better than those of the crude extract of maggots.Of 24 tubes offiltrates,the antibacterial effects of filtrates in tubes 4,5 and 11 were significantly higher than those of the control.The molecular weight of the protein in filtrates in tubes 4,5 and 11 was about 15 k Da.CONCLUSION:The crude extract of maggots exhibits obvious,dose-dependent antibacterial effects.The crude extract exerts antibacterial effects by changing the bacterial membrane permeability and inhibiting plasmid DNA replication.The prote in that has antibacterial effects in the crude extract of maggots has a molecular weight of about 15 k Da.     

Antimicrobial activity and synergism of Sami-Hyanglyun-Hwan with ciprofloxacin against methicillin-resistant Staphylococcus aureus

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.     

Topical antibacterial agents

Topical antibacterial agents occupy an important niche of antimicrobial therapy for both inpatients and outpatients. These agents, including antiseptic and antibiotic preparations, are used for prophylaxis and treatment of infection. Prophylactic uses include application for traumatic and surgical wounds, burns, intravascular catheters, and eradication of S. aureus nasal carriage. Topical antibacterial agents are also used for treatment of primary and secondary pyodermas. Individual antibacterial agents have been reviewed. Of note, despite the widespread use of topical antibacterial agents, further data on which to guide therapy are needed in many instances.     

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentration at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications of these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.     

Pharmacodynamics of antibacterial drugs

Pharmacodynamics of antibacterial agents relates the time course of drug concentration to its antimicrobial effects at the infection site. Antibacterial agents can be divided into three groups based on pharmacodynamic characteristics: agents that exhibit concentration-dependent bactericidal activity over a range of drug concentrations (e.g., aminoglycosides and fluoroquinolones); agents that exhibit time-dependent bactericidal activity that has little relationship to the magnitude of concentration, provided the concentrations are above a minimally effective level (e.g., beta-lactam antibiotics and vancomycin); and agents that exhibit a predominantly bacteriostatic effect. Knowledge of antimicrobial pharmacodynamics provides a rational basis for determining optimal regimens of dosage amounts and length of dosage intervals.