AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METH...AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.展开更多
Antibacterial thermoplastic polyurethane （TPU） electrospun fiber mats were prepared by adsorption of Ag nanoparticles （Ag NPs） onto TPU/3-aminopropyltriethoxysilane （APS） co-electrospun fiber mats from silver so...Antibacterial thermoplastic polyurethane （TPU） electrospun fiber mats were prepared by adsorption of Ag nanoparticles （Ag NPs） onto TPU/3-aminopropyltriethoxysilane （APS） co-electrospun fiber mats from silver sol. The use of APS can functionalize TPU fibers with amino groups, facilitating the adsorption of Ag NPs. The effects of pH of silver sol and APS content on Ag NP adsorption and antibacterial activity were investigated. Ag NP adsorption was evidenced by TEM, XPS and TGA. Significant Ag NP adsorption occurred at pH = 3-5, The main driving force for Ag NP adsorption is electrostatic interaction between --NH3^＋ of the fibers and --COO- derived from the --COOH group capped on the surfaces of Ag NPs. The antibacterial activity of the Ag NP-decorated TPU/APS fiber mats was investigated using both gram-negative Escherichia coli and gram-positive Bacillus subtilis. The antibacterial rate increases with increasing APS content up to 5% where the antibacterial rates against both types of bacteria are over 99.9%.展开更多
Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical a...Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical and pathogenicity tests, alongside PCR analyses, were conducted to identify the local isolates of Erwinia amylovora. The alternative antagonistic microorganisms which combat bacterium E. amylovora were tested within in vitro and in vivo conditions. The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues. Streptomyces strain C1-4 suppressed E. amylovora disease symptoms in the leaf tissues and excised apple and pear shoots. The incidence of fire blight on leaves was reduced by about 70% with two applications of bacterial antagonists. Further studies at different locations in Kyrgyzstan, using large scale application, would allow for stronger recommendations to be made, including studies and recommendations on their ability to prevent disease and to use them as main components in an integrated pest management program.展开更多
Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt (Ca (II)-EDTA) was investigated for its antibacterial activity against the periodontal pathogens Aggregatibacter actinomycetemcomitans, Prevotell...Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt (Ca (II)-EDTA) was investigated for its antibacterial activity against the periodontal pathogens Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Porphyromonas gingivalis. We determined the minimum inhibitory concentrations (MIC) of Ca (II)-EDTA and its bactericidal activity. Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt inhibited the growth of all the periodontopathic bacteria tested in broth. An MIC of 60 mM was the most effective against P. gingivalis. An adenosine triphosphate bioluminescence assay revealed that Ca (II)-EDTA showed bactericidal activity against the bacteria tested in a time-dependent manner. To determine its safety in mammalian cells, we investigated the viability of murine L929 cells subjected to Ca (II)-EDTA treatment. At 75 mM, 93% ± 0.13% of the cells survived. These results indicate that Ca (II)-EDTA is a candidate chelating agent for prevention of infection by periodontopathic bacteria.展开更多
【目的】探讨光合细菌菌剂在不同浓度下对番荔枝果园土壤微环境及果实品质的改善效果,为番荔枝的绿色施肥提供科学依据。【方法】以‘Gefner’番荔枝为试验材料,设置了4个不同施用量的光合细菌菌剂处理,即每160 m^(2)处理区喷施300(T_(...【目的】探讨光合细菌菌剂在不同浓度下对番荔枝果园土壤微环境及果实品质的改善效果,为番荔枝的绿色施肥提供科学依据。【方法】以‘Gefner’番荔枝为试验材料,设置了4个不同施用量的光合细菌菌剂处理,即每160 m^(2)处理区喷施300(T_(1))、600(T_(2))、900(T_(3))、1200 m L(T_(4))的菌剂,同时设立喷施清水为对照(CK)处理,研究不同浓度光合细菌菌剂对果园土壤理化性质、酶活性、微生物数量及果实品质的影响。【结果】与CK相比,光合细菌菌剂的施用显著改善了番荔枝果园的土壤微环境和果实品质。在T_(3)处理下,番荔枝果园土壤的理化性质得到了显著提高,其中有机质含量、碱解氮含量、有效磷含量、速效钾含量和阳离子交换量等指标分别提升了18.06%、35.68%、20.88%、52.20%、15.65%;同时,酶活性也得到了显著增强,脲酶活性、蛋白酶活性、过氧化氢酶活性和蔗糖酶活性等分别提高了21.88%、10.93%、19.61%、23.09%;此外,土壤微生物生态得到有效调节,细菌数量和放线菌数量显著增加了50.44%、28.46%,而真菌数量则显著减少了18.73%;有效地提高果实的品质和产量,果实中的总糖含量、总酸含量、可溶性固形物含量、维生素C含量等分别提高了10.10%、11.65%、6.54%、28.48%,同时果实的产量也显著提高了8.33%。【结论】光合细菌菌剂的施用对番荔枝果园的土壤理化性质和微生物生态具有显著的改善作用,能够提高土壤中细菌和放线菌的数量,降低土壤中的真菌数量,同时显著提高番荔枝的果实产量与品质。其中,T_(3)处理的光合细菌菌剂对番荔枝的综合改善效果最为明显。展开更多
Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade mi...Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.展开更多
文摘AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.
基金financially supported by the National Natural Science Foundation of China(No.51173093)
文摘Antibacterial thermoplastic polyurethane （TPU） electrospun fiber mats were prepared by adsorption of Ag nanoparticles （Ag NPs） onto TPU/3-aminopropyltriethoxysilane （APS） co-electrospun fiber mats from silver sol. The use of APS can functionalize TPU fibers with amino groups, facilitating the adsorption of Ag NPs. The effects of pH of silver sol and APS content on Ag NP adsorption and antibacterial activity were investigated. Ag NP adsorption was evidenced by TEM, XPS and TGA. Significant Ag NP adsorption occurred at pH = 3-5, The main driving force for Ag NP adsorption is electrostatic interaction between --NH3^＋ of the fibers and --COO- derived from the --COOH group capped on the surfaces of Ag NPs. The antibacterial activity of the Ag NP-decorated TPU/APS fiber mats was investigated using both gram-negative Escherichia coli and gram-positive Bacillus subtilis. The antibacterial rate increases with increasing APS content up to 5% where the antibacterial rates against both types of bacteria are over 99.9%.
文摘Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical and pathogenicity tests, alongside PCR analyses, were conducted to identify the local isolates of Erwinia amylovora. The alternative antagonistic microorganisms which combat bacterium E. amylovora were tested within in vitro and in vivo conditions. The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues. Streptomyces strain C1-4 suppressed E. amylovora disease symptoms in the leaf tissues and excised apple and pear shoots. The incidence of fire blight on leaves was reduced by about 70% with two applications of bacterial antagonists. Further studies at different locations in Kyrgyzstan, using large scale application, would allow for stronger recommendations to be made, including studies and recommendations on their ability to prevent disease and to use them as main components in an integrated pest management program.
文摘Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt (Ca (II)-EDTA) was investigated for its antibacterial activity against the periodontal pathogens Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Porphyromonas gingivalis. We determined the minimum inhibitory concentrations (MIC) of Ca (II)-EDTA and its bactericidal activity. Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt inhibited the growth of all the periodontopathic bacteria tested in broth. An MIC of 60 mM was the most effective against P. gingivalis. An adenosine triphosphate bioluminescence assay revealed that Ca (II)-EDTA showed bactericidal activity against the bacteria tested in a time-dependent manner. To determine its safety in mammalian cells, we investigated the viability of murine L929 cells subjected to Ca (II)-EDTA treatment. At 75 mM, 93% ± 0.13% of the cells survived. These results indicate that Ca (II)-EDTA is a candidate chelating agent for prevention of infection by periodontopathic bacteria.
文摘【目的】探讨光合细菌菌剂在不同浓度下对番荔枝果园土壤微环境及果实品质的改善效果,为番荔枝的绿色施肥提供科学依据。【方法】以‘Gefner’番荔枝为试验材料,设置了4个不同施用量的光合细菌菌剂处理,即每160 m^(2)处理区喷施300(T_(1))、600(T_(2))、900(T_(3))、1200 m L(T_(4))的菌剂,同时设立喷施清水为对照(CK)处理,研究不同浓度光合细菌菌剂对果园土壤理化性质、酶活性、微生物数量及果实品质的影响。【结果】与CK相比,光合细菌菌剂的施用显著改善了番荔枝果园的土壤微环境和果实品质。在T_(3)处理下,番荔枝果园土壤的理化性质得到了显著提高,其中有机质含量、碱解氮含量、有效磷含量、速效钾含量和阳离子交换量等指标分别提升了18.06%、35.68%、20.88%、52.20%、15.65%;同时,酶活性也得到了显著增强,脲酶活性、蛋白酶活性、过氧化氢酶活性和蔗糖酶活性等分别提高了21.88%、10.93%、19.61%、23.09%;此外,土壤微生物生态得到有效调节,细菌数量和放线菌数量显著增加了50.44%、28.46%,而真菌数量则显著减少了18.73%;有效地提高果实的品质和产量,果实中的总糖含量、总酸含量、可溶性固形物含量、维生素C含量等分别提高了10.10%、11.65%、6.54%、28.48%,同时果实的产量也显著提高了8.33%。【结论】光合细菌菌剂的施用对番荔枝果园的土壤理化性质和微生物生态具有显著的改善作用,能够提高土壤中细菌和放线菌的数量,降低土壤中的真菌数量,同时显著提高番荔枝的果实产量与品质。其中,T_(3)处理的光合细菌菌剂对番荔枝的综合改善效果最为明显。
基金The Long-Term Research Grant(LRGS)of the Ministry of Education of Malaysia supported this work
文摘Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.
