AIM： Methicillin-resistant Staphylococcus aureus （MRSA） is a pathogenic bacterium that causes both hospital- and community-acquired infections, and for which single-drug treatments are becoming less efficient. Rhiz...AIM： Methicillin-resistant Staphylococcus aureus （MRSA） is a pathogenic bacterium that causes both hospital- and community-acquired infections, and for which single-drug treatments are becoming less efficient. Rhizoma coptidis has been used for more than two thousand years in China to treat diarrhea, fever, and jaundice. In this study, the anti-MRSA activity of Rhizoma coptidis is examined and its effective components sought. METHODS： The mecA and norA genes were determined by PCR amplification and sequencing. Drug susceptibility of Staphylococcus aureus ATCC43300 was performed using the VITEK2 compact system. The chemical fingerprint of Rhizoma coptidis was investigated using HPLC and preparative liquid chromatography, and the anti-MRSA activity was determined using an improved broth microdilution method. RESULTS： The drug susceptibility test revealed that the penicillin-binding protein phenotype of the strain changed in comparison to penicillin-sensitive Staphylococcus aureus. Ten batches of Rhizoma coptidis showed anti-MRSA activity on the norA-negative Staphylococcus aureus strain, as well as the strain that contained a norA gene. The spectrum-effect relationship revealed that the berberine alkaloids were the effective components, within which berberine, coptisine, palmatine, epiberberine,, and jatrorrhizine were the major components. CONCLUSION： This study lays a foundation for in vivo studies of Rhizoma eoptidis and for the development of multi-component drugs.展开更多
In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing e...In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host＇s defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.展开更多
[Objective] The aim was to explore the antibacterial effect of in -vitro combined application of imipenem and ceftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox on E. coliATCC25922. [Methods] Th...[Objective] The aim was to explore the antibacterial effect of in -vitro combined application of imipenem and ceftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox on E. coliATCC25922. [Methods] The minimum inhibition concentration of all kinds of the drugs to E. co/i ATCC25922 was determined and bacteriostatic effect of imipenem and ceffriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox on E. coli ATCC＇25922 was determined with chessboard microdilution method. [ Results] Combined applications of imipenem and caftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox to E. coli ATCC25922 revealed synergistic effects. [ Ceedusion] Combined applications of imipenem and ceftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox greatly reduced drug dosa,qe, imDroved the druq effect, and provided theoretical support for clinical medicine.展开更多
[Objective] The paper was to investigate in vitro antibacterial effect of alkaline hydrogen water on Escherichia coli,Salmonella,Pseudomonas aeruginosa and Staphylococcus aureus.[Method] With Cortex cinnamomi extract...[Objective] The paper was to investigate in vitro antibacterial effect of alkaline hydrogen water on Escherichia coli,Salmonella,Pseudomonas aeruginosa and Staphylococcus aureus.[Method] With Cortex cinnamomi extract（1 g/m L） and pure water as the control,the minimal inhibitory concentrations（MIC） against four kinds of common pathogenic microorganisms were tested through microdilution method.[Result] When the alkaline hydrogen water was diluted to 1/8 times of the original concentration,it had significant antibacterial effects on four kinds of common mi-croorganisms with the concentration of 1.5 ×10^5 CFU/m L,which had equivalent effect with C.cinnamomi extract group.[Conclusion]The alkaline hydrogen water has remarkable antibacterial effects on the four kinds of common microorganisms,which may provide a new important way for pre-venting disease occurrence and reducing the harms of pathogenic microorganisms.展开更多
[ Objective] This paper aimed to understand drug resistance of Escherichia coli isolated from pets in Guangzhou. I Method ] Broth microdilution method was used to determine the minimal inhibitory concentration （MIC）...[ Objective] This paper aimed to understand drug resistance of Escherichia coli isolated from pets in Guangzhou. I Method ] Broth microdilution method was used to determine the minimal inhibitory concentration （MIC） of ceftiofur, enrofloxacin and other 11 kinds of antibiotics for antimicrobial agent susceptibility testing of 120 strains of clinical E. coli and the experimental data were processed by WHONET 5.4 software. Based on the results of drug resistance pattern analysis, it helped to analyze and study the resistance mechanism. EResultl Clinical E. coli isolated from pets showed a different drug resistance to the 13 kinds of veterinary clinical antibiotics, and the different sources of E. coli also showed a different drug resistance pattern.[Cenclmion] The study provided a theoretical basis for the clinical use of drugs and druq resistance surveillance.展开更多
The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by ep...The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by epidemiological cut-off(ECOFF)finder against E.coli from chickens in China.Anal swabs were collected from chicken farms in China.BMD method was used to measure MIC50 and MIC90 of colistin which were 2 and 4μg•mL^(-1),respectively.MIC frequency distributions for colistin were used to estimate preliminary ECV(8μg•mL^(-1)).High percentages of resistance to ampicillin(94.12%),nalidixic acid(94.12%),enrofloxacin(94.12%),tetracycline(94.12%),ciprofloxacin(88.24%),florfenicol(88.24%),neomycin(64.71%),gentamicin(58.82%),levofloxacin(58.82%),doxycycline(88.24%)and cefalexin(76.47%)were found.In addition,low percentages of resistance to amikacin(5.88%),spectinomycin(17.65%)and fosfomycin(41.18%)were noted.Notably,amoxicillin,sulfisoxazole and trimethoprim resulted in a 100%resistance generation efficacy rate.Prevalence of mcr-1 in E.coli(9/17)in chromosomal DNA was higher than mcr-4(2/17)gene,and mcr-1(5/17)was higher than mcr-4(3/17)in plasmid.展开更多
基金supported by the National Natural Science Foundation of China(No.81073043)
文摘AIM： Methicillin-resistant Staphylococcus aureus （MRSA） is a pathogenic bacterium that causes both hospital- and community-acquired infections, and for which single-drug treatments are becoming less efficient. Rhizoma coptidis has been used for more than two thousand years in China to treat diarrhea, fever, and jaundice. In this study, the anti-MRSA activity of Rhizoma coptidis is examined and its effective components sought. METHODS： The mecA and norA genes were determined by PCR amplification and sequencing. Drug susceptibility of Staphylococcus aureus ATCC43300 was performed using the VITEK2 compact system. The chemical fingerprint of Rhizoma coptidis was investigated using HPLC and preparative liquid chromatography, and the anti-MRSA activity was determined using an improved broth microdilution method. RESULTS： The drug susceptibility test revealed that the penicillin-binding protein phenotype of the strain changed in comparison to penicillin-sensitive Staphylococcus aureus. Ten batches of Rhizoma coptidis showed anti-MRSA activity on the norA-negative Staphylococcus aureus strain, as well as the strain that contained a norA gene. The spectrum-effect relationship revealed that the berberine alkaloids were the effective components, within which berberine, coptisine, palmatine, epiberberine,, and jatrorrhizine were the major components. CONCLUSION： This study lays a foundation for in vivo studies of Rhizoma eoptidis and for the development of multi-component drugs.
文摘In dairy and food industries lactic acid bacteria （LAB） have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host＇s defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.
文摘[Objective] The aim was to explore the antibacterial effect of in -vitro combined application of imipenem and ceftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox on E. coliATCC25922. [Methods] The minimum inhibition concentration of all kinds of the drugs to E. co/i ATCC25922 was determined and bacteriostatic effect of imipenem and ceffriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox on E. coli ATCC＇25922 was determined with chessboard microdilution method. [ Results] Combined applications of imipenem and caftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox to E. coli ATCC25922 revealed synergistic effects. [ Ceedusion] Combined applications of imipenem and ceftriaxone sodium, imipenem and cefotaxime sodium, amikacin and maquinox greatly reduced drug dosa,qe, imDroved the druq effect, and provided theoretical support for clinical medicine.
文摘[Objective] The paper was to investigate in vitro antibacterial effect of alkaline hydrogen water on Escherichia coli,Salmonella,Pseudomonas aeruginosa and Staphylococcus aureus.[Method] With Cortex cinnamomi extract（1 g/m L） and pure water as the control,the minimal inhibitory concentrations（MIC） against four kinds of common pathogenic microorganisms were tested through microdilution method.[Result] When the alkaline hydrogen water was diluted to 1/8 times of the original concentration,it had significant antibacterial effects on four kinds of common mi-croorganisms with the concentration of 1.5 ×10^5 CFU/m L,which had equivalent effect with C.cinnamomi extract group.[Conclusion]The alkaline hydrogen water has remarkable antibacterial effects on the four kinds of common microorganisms,which may provide a new important way for pre-venting disease occurrence and reducing the harms of pathogenic microorganisms.
基金supported by the Special Fund Project for the Institute Science and Technology Development and Demostration Extention of Henan Provincial Academy of Argricultural Sciences(Research of Zoonotic Small Animal Diseases)the Project for the 2012 Annual"University Students'Innovation Training Program",Southwest University for Nationalities(201210656017)the Special Fund Project for the Central University Basic Scientific Research Fund,Southwest University for Nationalities(11NZYTD02)
文摘[ Objective] This paper aimed to understand drug resistance of Escherichia coli isolated from pets in Guangzhou. I Method ] Broth microdilution method was used to determine the minimal inhibitory concentration （MIC） of ceftiofur, enrofloxacin and other 11 kinds of antibiotics for antimicrobial agent susceptibility testing of 120 strains of clinical E. coli and the experimental data were processed by WHONET 5.4 software. Based on the results of drug resistance pattern analysis, it helped to analyze and study the resistance mechanism. EResultl Clinical E. coli isolated from pets showed a different drug resistance to the 13 kinds of veterinary clinical antibiotics, and the different sources of E. coli also showed a different drug resistance pattern.[Cenclmion] The study provided a theoretical basis for the clinical use of drugs and druq resistance surveillance.
基金Supported by the National Key Research and Development Program of China(2016YFD0501302)the National Natural Science Foundation of China(31772801)。
文摘The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by epidemiological cut-off(ECOFF)finder against E.coli from chickens in China.Anal swabs were collected from chicken farms in China.BMD method was used to measure MIC50 and MIC90 of colistin which were 2 and 4μg•mL^(-1),respectively.MIC frequency distributions for colistin were used to estimate preliminary ECV(8μg•mL^(-1)).High percentages of resistance to ampicillin(94.12%),nalidixic acid(94.12%),enrofloxacin(94.12%),tetracycline(94.12%),ciprofloxacin(88.24%),florfenicol(88.24%),neomycin(64.71%),gentamicin(58.82%),levofloxacin(58.82%),doxycycline(88.24%)and cefalexin(76.47%)were found.In addition,low percentages of resistance to amikacin(5.88%),spectinomycin(17.65%)and fosfomycin(41.18%)were noted.Notably,amoxicillin,sulfisoxazole and trimethoprim resulted in a 100%resistance generation efficacy rate.Prevalence of mcr-1 in E.coli(9/17)in chromosomal DNA was higher than mcr-4(2/17)gene,and mcr-1(5/17)was higher than mcr-4(3/17)in plasmid.
