Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal...Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal stool specimens.Methods:The preliminary phytochemical screening was performed by the standard methods as described by Harborne.Cold extraction method was employed to extract the bioactive compounds from mango seed kernel.Disc diffusion method was adopted to screen antibacterial activity.Minimum inhibitory concentration(MIC) was evaluated by agar dilution method.The crude extracts were partially purified by thin layer chromatography(TLC) and the fractions were analyzed by high performance thin layer chromatography(HFTLC) to identify the bioactive compounds.Results:Phytochemical scrutiny of M.indica indicated the presence of phytochemical constituents such as alkaloids,gums, flavanoids,phenols,saponins,steroids,tannins and xanthoproteins.Antibacterial activity was observed in two crude extracts and various fractions viz.hexane,benzene,chlor of orm,methanol and water.MIC of methanol fraction was found to be(95±11.8)μg/mL.MIC of other fractions ranged from 130-380μg/mL Conclusions:The present study confirmed that each crude extracts and fractions of M.indica have significant antimicrobial activity against the isolated pathogen 5. dyserUeriae.The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel.The phytochemical tannin could be the reason for its antibacterial activity.展开更多
In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was...In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was performed at the level of culture medium and cell experiment. The gene expression profiles of the mutants and the wild-type strains under iron- enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. The results showed that all the mutants grew obviously less well than the wild-type strains in L broth appending iron chelator DIP. The addition of iron to the cultures can stimulate the growth of mutants back to wild-type levels. In either the experiments on the ability of intracellular multiplication or the cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obvious change in virulence compared with the parental strain SD51197. However when DIP was added to the cultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reduced about 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limited condition showed that the mutants were more sensitive for the changes of iron deficiency than the wild-type strains, many genes have been altered. Up-regulated genes mainly involved genes of transcription, coenzyme metabolism, amino acid transport and metabolism, and unknown functional genes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism and unknown function genes; the expression levels of known iron-transport associated genes generally showed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA were likely to have some effects on the virulence and growth of S. dysenteriae.展开更多
应用PCR技术从Ⅰ型痢疾志贺茵(Shigella dysenteriae type Ⅰ)中,分别扩增出约895bp和225bp的成熟ShT-A,B基因片段,直接克隆至pGEM-T载体中,经蓝白斑筛选、PCR和双酶切鉴定正确后,命名为pGEM-ShTA_2和pGEM-ShTB_3。测序结果表明,插入的...应用PCR技术从Ⅰ型痢疾志贺茵(Shigella dysenteriae type Ⅰ)中,分别扩增出约895bp和225bp的成熟ShT-A,B基因片段,直接克隆至pGEM-T载体中,经蓝白斑筛选、PCR和双酶切鉴定正确后,命名为pGEM-ShTA_2和pGEM-ShTB_3。测序结果表明,插入的片段是ShT-A,ShT-B,且与GenBank中ShT-A,B核酸序列完全一致,从而为重组ShT-A,B的表达研究奠定了基础。展开更多
文摘Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal stool specimens.Methods:The preliminary phytochemical screening was performed by the standard methods as described by Harborne.Cold extraction method was employed to extract the bioactive compounds from mango seed kernel.Disc diffusion method was adopted to screen antibacterial activity.Minimum inhibitory concentration(MIC) was evaluated by agar dilution method.The crude extracts were partially purified by thin layer chromatography(TLC) and the fractions were analyzed by high performance thin layer chromatography(HFTLC) to identify the bioactive compounds.Results:Phytochemical scrutiny of M.indica indicated the presence of phytochemical constituents such as alkaloids,gums, flavanoids,phenols,saponins,steroids,tannins and xanthoproteins.Antibacterial activity was observed in two crude extracts and various fractions viz.hexane,benzene,chlor of orm,methanol and water.MIC of methanol fraction was found to be(95±11.8)μg/mL.MIC of other fractions ranged from 130-380μg/mL Conclusions:The present study confirmed that each crude extracts and fractions of M.indica have significant antimicrobial activity against the isolated pathogen 5. dyserUeriae.The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel.The phytochemical tannin could be the reason for its antibacterial activity.
文摘In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was performed at the level of culture medium and cell experiment. The gene expression profiles of the mutants and the wild-type strains under iron- enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. The results showed that all the mutants grew obviously less well than the wild-type strains in L broth appending iron chelator DIP. The addition of iron to the cultures can stimulate the growth of mutants back to wild-type levels. In either the experiments on the ability of intracellular multiplication or the cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obvious change in virulence compared with the parental strain SD51197. However when DIP was added to the cultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reduced about 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limited condition showed that the mutants were more sensitive for the changes of iron deficiency than the wild-type strains, many genes have been altered. Up-regulated genes mainly involved genes of transcription, coenzyme metabolism, amino acid transport and metabolism, and unknown functional genes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism and unknown function genes; the expression levels of known iron-transport associated genes generally showed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA were likely to have some effects on the virulence and growth of S. dysenteriae.
文摘应用PCR技术从Ⅰ型痢疾志贺茵(Shigella dysenteriae type Ⅰ)中,分别扩增出约895bp和225bp的成熟ShT-A,B基因片段,直接克隆至pGEM-T载体中,经蓝白斑筛选、PCR和双酶切鉴定正确后,命名为pGEM-ShTA_2和pGEM-ShTB_3。测序结果表明,插入的片段是ShT-A,ShT-B,且与GenBank中ShT-A,B核酸序列完全一致,从而为重组ShT-A,B的表达研究奠定了基础。
