[ Objective] This study aimed to screen and preliminarily identify LactobaciUus strain CW3. [ Method] Oxford cup double-plate method was used for preliminary screening of broad-spectrum bacteriacin-producing Lactobaci...[ Objective] This study aimed to screen and preliminarily identify LactobaciUus strain CW3. [ Method] Oxford cup double-plate method was used for preliminary screening of broad-spectrum bacteriacin-producing LactobaciUus strain; after eliminating the interference of organic acid and hydrogen peroxide, antibac- terial substances containing protein properties produced by the screened strain were detected; finally, the obtained strain was identified. [ Result] After elimination of interference factors such as organic acid and hydrogen peroxide, the fermentation supernatant of strain CW3 could stil｜ inhibit the growth of indicator strains; the antibacterial activity of fermentation broth was significantly reduced after treatment with trypsase and pepsase, which indicated that the produced antibacterial sub- stances were bacteriocins. Results of physiological and biochemical identification showed that strain CW3 belonged to Lactobacillus plantarum. [ Conclusion] CW3 is a broad-spectrum bacteriocin-producing LactobaciUus plantarum strain.展开更多
In clinical practice,the important hygienic prevention of bacterial pathogen spread is disinfection of potentially contaminated area.Benzalkonium bromide and chlorhexidine acetate are commonly used disinfectants with ...In clinical practice,the important hygienic prevention of bacterial pathogen spread is disinfection of potentially contaminated area.Benzalkonium bromide and chlorhexidine acetate are commonly used disinfectants with a broad spectrum of antimicrobial effect.It is vital to inhibit the spread of pathogen in hospital.However,a large number of pathogens with the decreased antiseptic susceptibility have been isolated from clinical samples which showed an increased minimal inhibitory concentration(MIC)against those antiseptics.These resistant pathogens are the major causes for nosocomial crossinfections in hospital.The present study demonstrated the utility of Oxford plate assay system in determining the potential disinfectant resistance of bacteria.The microbiological assay is based on the inhibitory effect of tested disinfectants upon the strains of Staphylococcus aureus and Escherichia coli.Statistical analysis of the bioassay results indicated the linear correlation(r=-0.87-0.99,P<0.01)between the diameter of growth inhibition zone and the log dosage of the tested disinfectants.Moreover,comparison of inhibitory efficacy of benzalkonium bromide upon 29 S.aureus strains isolated from clinical samples by both Oxford plate method and broth dilution method showed that the diameter of growth inhibition zone has significantly negative correlation with the minimal inhibitory concentration(MIC)(r=-0.574,P<0.001).These results suggest that the Oxford plate is a simple and time-saving method in detecting potential clinical disinfectant resistance and its usefulness for routine surveillance of pathogenic resistance to disinfectants warrants further investigation.展开更多
基金Supported by National Natural Science Foundation of China(41101244)Project of Basic and Advanced Research of Henan Province(122300410161)Natural Science Research Project of the Education Department of Henan Province(2010B180029)
文摘[ Objective] This study aimed to screen and preliminarily identify LactobaciUus strain CW3. [ Method] Oxford cup double-plate method was used for preliminary screening of broad-spectrum bacteriacin-producing LactobaciUus strain; after eliminating the interference of organic acid and hydrogen peroxide, antibac- terial substances containing protein properties produced by the screened strain were detected; finally, the obtained strain was identified. [ Result] After elimination of interference factors such as organic acid and hydrogen peroxide, the fermentation supernatant of strain CW3 could stil｜ inhibit the growth of indicator strains; the antibacterial activity of fermentation broth was significantly reduced after treatment with trypsase and pepsase, which indicated that the produced antibacterial sub- stances were bacteriocins. Results of physiological and biochemical identification showed that strain CW3 belonged to Lactobacillus plantarum. [ Conclusion] CW3 is a broad-spectrum bacteriocin-producing LactobaciUus plantarum strain.
文摘In clinical practice,the important hygienic prevention of bacterial pathogen spread is disinfection of potentially contaminated area.Benzalkonium bromide and chlorhexidine acetate are commonly used disinfectants with a broad spectrum of antimicrobial effect.It is vital to inhibit the spread of pathogen in hospital.However,a large number of pathogens with the decreased antiseptic susceptibility have been isolated from clinical samples which showed an increased minimal inhibitory concentration(MIC)against those antiseptics.These resistant pathogens are the major causes for nosocomial crossinfections in hospital.The present study demonstrated the utility of Oxford plate assay system in determining the potential disinfectant resistance of bacteria.The microbiological assay is based on the inhibitory effect of tested disinfectants upon the strains of Staphylococcus aureus and Escherichia coli.Statistical analysis of the bioassay results indicated the linear correlation(r=-0.87-0.99,P<0.01)between the diameter of growth inhibition zone and the log dosage of the tested disinfectants.Moreover,comparison of inhibitory efficacy of benzalkonium bromide upon 29 S.aureus strains isolated from clinical samples by both Oxford plate method and broth dilution method showed that the diameter of growth inhibition zone has significantly negative correlation with the minimal inhibitory concentration(MIC)(r=-0.574,P<0.001).These results suggest that the Oxford plate is a simple and time-saving method in detecting potential clinical disinfectant resistance and its usefulness for routine surveillance of pathogenic resistance to disinfectants warrants further investigation.
