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ABSTRACT: To assess the safety of Bifidobacterium longum (B. longum) JDM301 based on complete genome sequences.
The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resistance genes and genes encoding enzymes responsible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test.
JDM301 was shown to contain 36 genes associated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence factors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, amikacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imipenem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated.
The safety assessment of JDM301 using information derived from complete bacterial genome will contribute to a wider and deeper insight into the safety of probiotic bacteria.
World Journal of Gastroenterology 02/2012; 18(5):479-88. · 2.47 Impact Factor
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ABSTRACT: We performed a comprehensive safety assessment of a probiotic based on the whole genome sequence and corresponding phenotypes. This was performed on Lactobacillus plantarum JDM1, a widely used commercial probiotic strain in China. The minimal inhibitory concentrations (MICs) of sixteen antibiotics and the biogenic amine production of JDM1 were tested to supplement a traditional oral toxicity test. In total, fifty-one antibiotic resistance-associated genes, one hundred twenty-six virulence-associated genes, and twenty-three adverse metabolism-associated genes were found in JDM1. However, there were no toxin or hemolysin encoding genes, and safety-associated genes were rarely transferable. This approach can be generalized to provide a deep safety investigation of novel probiotic strains and greatly reveal the potential danger determinants and their molecular mechanisms. However, this kind of analysis reveals the theoretical maximum risk level as not all genes are efficient depending on environmental conditions.
International journal of food microbiology 11/2011; 153(1-2):166-70. · 3.01 Impact Factor
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ABSTRACT: Bifidobacteria, known as probiotic bacteria, are high-G+C Gram-positive bacteria which naturally inhabit the human gastrointestinal tract and vagina. Recently, we completely sequenced Bifidobacterium longum JDM301, which is a widely used Chinese commercial strain with several probiotic properties.
Journal of bacteriology 08/2010; 192(15):4076-7. · 3.94 Impact Factor
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ABSTRACT: To test the effects of the 21.5 kDa human brain myelin basic protein (MBP) on the proliferation and apoptosis of HepG-2.
pSVCEP-MBP-CAT plasmid containing the full-length 21.5 kDa MBP cDNA was transfected into human hepatoma carcinoma cells (HepG-2). The pSVCEP-CAT vector transfected HepG-2 cells served as negative control. RT-PCR and Western blot were performed to confirm the effectiveness of the transfection. MTT measures were used to determine the proliferative curve of cells. H2O2 was then added to induce cell apoptosis. DNA ladder, immunohistochemistry assay, comet electrophoresis and TUNEL (Terminal Deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling) were used to detect the apoptosis and relevant protein expressions.
The 21.5 KDa MBP cDNA was transfected into HepG-2 cells successfully. MTT measures of pSVCEP-MBP-CAT transfected group showed increased proliferation and anti-apoptosis. The control group displayed with more typical DNA ladders and much higher level of Caspase-3 than the MBP group. Comet and TUNEL assays revealed that the control group cells had significant DNA damages and serious apoptosis, whereas the MBP group showed slight changes.
The 21.5 kDa MBP promotes the proliferation of HepG-2 and blocks apoptosis.
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 09/2009; 40(5):775-9.
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ABSTRACT: Procationic-liposome-protamine-DNA (PLPD) vector, a novel nonviral gene delivery system, that may further adsorb transferrin (Tf) at its surface via electrostatic interactions to form Tf-PLPD, was prepared from soybean phosphatidylcholine (PC), cholesterol (Chol), and a kind of cholesterol derivative, CHETA(cholest-5-en-3-ol(3beta)-[2-[[4-[(carboxymethyl)dithio]-1-iminobutyl] amino] ethyl] carba- mate) containing disulfide bond by film dispersion-filteration method. Central composite design was used to optimize the formulation. The presence of serum did not affect the transfection activity of PLPD or Tf-PLPD and the cell viability was not affected significantly when the cells were incubated with the complexes for 4 hr at 37 degrees C. Compared with one kind of cationic liposomes(liposome-protamine-DNA), the PLPD had much less cytotoxicity to three hepar cell lines(including HepG2, SMMC7721, and Chang's normal heptocyte). The procationic lipoplex described here, combining the condensing effect of protamine and the targeting capability of Tf, was a perspective nonviral vector for gene delivery system.
Drug Delivery 04/2007; 14(3):177-83. · 1.46 Impact Factor
