No abstract available.
DNA* ; Kidney* ; Plasmids*

This study aimed to extract and type the plasmids of S. typhi strains and antibiogram. 2 S. typhi strains were selected. One multi-antibiotic resistant strain carried only R-plasmid and the other sensitive strain carried 2 smaller plasmids. Both of them were cultured and extracted DNA plasmid. Then 20 different enzymes were analysed to choose proper enzymes. There were 7 enzymes met the requirements. For DNA of larger plasmid, Kpn 1 and Sca 1 cut to 11 fractions. All of them had lower molecular weight than standard DNA. For DNA of smaller plasmid, Kpn 1 enzyme cut to 16 fractions, BamH 1 cut to 10 fractions, Mlu cut to 9 fractions, Cla cut to 11 fractions, and Bgl II cut to 7 fractions. All these fractions had lower weight than standard DNA. Molecular weight of larger plasmid is 188 206bp X 660D = 124 215 960D (124MD). That of smaller plasmid is 99 731bp X 660D = 65 822 460D.
Plasmids ; Molecular Weight

We investigated the effect of toxin-antitoxin (TA) systems in bla(CTX-M-15)-bearing plasmids of Klebsiella pneumoniae on persister formation. The persister formation rate was notably high in transconjugants in plasmids bearing TA system than the transconjugants in plasmids bearing no TA systems. Activation of relA and spoT expression was higher in transconjugants with plasmids bearing TA systems. Thus, TA systems in plasmids may contribute to the maintenance of bla(CTX-M-15)-bearing plasmids and host survival via persister formation.
Klebsiella pneumoniae ; Klebsiella ; Plasmids

No abstract available.
Drug Resistance, Microbial* ; Plasmids* ; Pneumonia*

No abstract available.
Plasmids* ; Shigella* ; Virulence Factors* ; Virulence*

Aims: Expression of recombinant proteins across a range of different host organisms has profound contribution to the advancement in biotechnology. In this study, we aimed to construct a highly versatile broad host range (BHR) expression vector, designated as pYL101C. Methodology and results: The Golden Gate cloning approach was used to construct pYL101C. Key features of pYL101C include a strong integron promoter (PINTc), a BHR pBBR1 origin of replication (ori), gentamycin resistance gene (GmR) as a selectable marker and a multiple cloning site (MCS) downstream of the promoter for easy-cloning purpose. To verify the functionality of pYL101C, we cloned the superfolder green fluorescent protein (sfGFP) reporter gene into pYL101C and transferred the resultant recombinant plasmid pYL101C::sfGFP into various Gram-negative bacteria. Transformants obtained stably expressed strong green fluorescence under blue light excitation even without selection after four passages. Conclusion, significance and impact of study The constructed BHR expression vector, pYL101C and recombinant pYL101C::sfGFP are stable and can be used to monitor the presence of Gram-negative bacteria, such as endophytes and pathogens in their hosts and environment.
Host Specificity ; Plasmids ; Cloning, Molecular

No abstract available.
DNA* ; Plasmids* ; Restriction Mapping* ; Yersinia enterocolitica* ; Yersinia*

OBJECTIVETo construct a eukaryotic vector which could express bone morphogenetic protein-7 (bmp-7) in MC3T3-E1.

METHODSBone morphogenetic protein-7 gene was obtained by RT-PCR from human embryo kidney. And after sequencing and electrophoresis the obtained aim DNA fragment was inserted into eukaryotic expression plasmid pcDNA3.1 (+) by using restricted endonuclease and ligase. The DNA sequence of the newly-constructed plamids was proved right by the gene technic company. And then the new plasmids containing right sequence aim gene were transfected into MC3T3-E1 cells by Lipofectamine 2000. 72 h after transfecting, RT-PCR was performed to show the transfected cells containing the aim gene, and the whole protein of the transfected cells were gathered and used as samples in the next Western blot to test the expression of bmp-7 gene.

RESULTSDNA sequencing indicated the sequence of the obtained bmp-7 was identical to the reported ones in GeneBank. The electrophoretic map of the products of RT-PCR and restriction enzyme digestion played another evidence that the newly-constructed plasmids were bmp-7/pcDNA3.1(+). The results of Western blot showed that the transfected cells could express BMP-7.

CONCLUSIONThe construction of a eukaryotic vector which could express BMP-7 in MC3T3-E1 was successful.

Recently, treatment for bacillary dysentery have meet many difficulty due to Shigella which antibiotic resistance. Most of Shigella strains also resistant to many antibiotics at the same time (multi-antibiotics). The aim of the research is finding out genes that are encoded antibiotic resistance, features about structure, activity mechanism as well as transmitable of the genes in community. Material and method: researched strains: 100 S.flexneri strains, standard strain: E.coli K12-J5-3. Tecnology: diffused paper slice. The result chosen Sflexneri strains that resistant multi-antibiotic from 237 primary strains. Among them, 100 strains have major resistant type is resistant to 5 kinds of antibiotic. The strains are chosen to receive to E.coli K12J5-3. The percentage of receipt are 56%. Most of receive type don’t get enough resistance to the 5 antibiotics.
Plasmids ; Genes ; Drug Resistance, Microbial ; Shigella flexneri

OBJECTIVETo observe the therapeutic effect of CDglyTK gene mediated by synthetic radiation-inducible promoter in the treatment of Tca8113 cells.

METHODSCDglyTK gene in pCEA-CDglyTK was subcloned into pcDNA3.1 (+) to construct plasmid pcDNA3.1 (+)-CDglyTK, and then the synthetic radiation-inducible promoter in pMD18 -T -E was inserted into pcDNA3.1 (+) -CDglyTK to construct plasmid pcDNA3.1 (+ )/E -CDglyTK. The recombinant plasmid was transfected into Tca8113 cells by lipofectamine, and then exposed to 3 Gy irradiation. Cytotoxicity was evaluated by MTT. The expression of CDglyTK gene was detected by RT-PCR. The apoptosis and proliferation were examined by flow cytomtery.

RESULTSThe plasmid pcDNA3.1 (+)/E-CDglyTK was constructed successfully. The comparative survival rate of Tca8113 cells was markedly decreased by induction irradiation. Up-regulation of CDglyTK expression was found in Tca8113 cells exposed to irradiation. The apoptosis index (AI) of Tca8113 cells exposed to irradiation was higher than that of Tca8113 cells without irradiation, the other way round, the proliferation index (PI) of Tca8113 cells exposed to irradiation was lower than that of Tca8113 cells without irradiation.

CONCLUSIONThe synthetic radiation-inducible promoter can be served as a molecular switch to improve the expression of CDglyTK gene in Tca8113 cells, and low dose induction radiation can significantly improve the therapeutic efficiency.