• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.368-377
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• 2020

Enterotoxigenic Bacteroides fragilis (ETBF) is the main pathogen causing severe inflammatory diseases and colorectal cancer. Its biofilm plays a key role in the development of colorectal cancer. The objective of this study was to determine the antagonistic effects of cell-free supernatants (CFS) derived from Clostridium butyricum against the growth and biofilm of ETBF. Our data showed that C. butyricum CFS inhibited the growth of B. fragilis in planktonic culture. In addition, C. butyricum CFS exhibited an antibiofilm effect by inhibiting biofilm development, disassembling preformed biofilms and reducing the metabolic activity of cells in biofilms. Using confocal laser scanning microscopy, we found that C. butyricum CFS significantly suppressed the proteins and extracellular nucleic acids among the basic biofilm components. Furthermore, C. butyricum CFS significantly downregulated the expression of virulence- and efflux pump-related genes including ompA and bmeB3 in B. fragilis. Our findings suggest that C. butyricum can be used as biotherapeutic agent by inhibiting the growth and biofilm of ETBF.

• Toxicological Research
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• v.29 no.2
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• pp.99-106
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• 2013

Clostridium difficile infection (CDI) has become a significant threat to public health. Although broad-spectrum antibiotic therapy is the primary treatment option for CDI, its use has evident limitations. Probiotics have been proved to be effective in the treatment of CDI and are a promising therapeutic option for CDI. In this study, 4 strains of lactic acid bacteria (LAB), namely, Lactobacillus rhamnosus (LR5), Lactococcuslactis (SL3), Bifidobacterium breve (BR3), and Bifidobacterium lactis (BL3) were evaluated for their anti-C. difficile activity. Co-culture incubation of C. difficile ($10^6$ and $10^{10}$ CFU/ml) with each strain of LAB indicated that SL3 possessed the highest antimicrobial activity over a 24-hr period. The cell-free supernatants of the 4 LAB strains exhibited $MIC_{50}$ values between 0.424 mg/ml (SL3) and 1.318 (BR3) mg/ml. These results may provide a basis for alternative therapies for the treatment of C. difficile-associated gut disorders.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.371-378
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• 1996

Three and 2 strains of E coli O157 were isolated from fecal materials of cattle (390) and pigs (420) in Korea, respectively. One strain of O157:H7 isolated from cattle and 2 strains of O157:H7 isolated from pigs were identified as verotoxin-1 (VT-1) produing strains and 2 strains (O157:H7 and O157:H-) isolated from cattle were identified as verotoxin-2 (VT-2) producing strains by neutralization test on HeLa and Vero cells. Culture supernatants of the isolates were cytotoxic to HeLa and Vero cells. The levels of cytotoxin produced by isolates were $10^2{\sim}10^4$ cytotoxic dose($CD_{50}$)/ml. Also, VT-2-converting bacteriophage was isolated from KSC109 strain which had been isolated from cattle. Molecular weight of the phage DNA was determined as approximately 45 Kb in 0.8% agarose gel electrophoresis, and morphology of the phage stained with phosphotungstic acid was observed by transmissible electron microscopy.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.57-63
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• 2006

We have cloned a xylanase gene (xynA) from Streptomyces thermocyaneoviolaceus. The deduced amino acid sequences of the XynA, including the active site sequences of glycosyl hydrolase family 10, showed high sequence homology with several xylanases assigned in this category. The XynA was overexpressed under an IPTG inducible T7 promoter control in E. coli BLR(DE3). The overproduced enzymes were excreted into culture supernatants and periplasmic space. The purified XynA had an apparent molecular mass of near 54 kDa, which corresponds to the molecular mass calculated from its gene. The optimum pH and temperature of the purified XynA were determined to be 5.0 and $65^{\circ}C$, respectively. The XynA retained over $90\%$ its activity after the heat treatment at $65^{\circ}C$ for 30 min. The XynA was highly efficient in producing xylose (X1), xylobiose (X2), xylotriose (X3), and xylotetraose (X4) from xylan.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.181-187
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• 2008

An entomopathogenic fungus, Paecilomyces fumosoroceus SFP-198 was isolated in Kyungbuk province, Korea and screened out for the control of Trialeurodes vaporariorum nymphs. It showed 72.5% efficacy against second instars of T. vaporariorum nymphs at 6 days after treatment in the laboratory. To select an active ingredient for the mass production and the formulation, SFP-198 culture products were compared based on their insecticidal activities against T. vaporariorum nymphs. Among them, conidia and blastospores showed much higher insecticidal activity than supernatants. Furthermore, SFP-198 conidia were more heat-resistant than blastospores, and also powder form of conidia was more stable than their suspension form. SFP-198 conidia showed high pathogenicity on not only T. vaporariorum but also Tetranychus urticae in the glasshouse. This result suggested that SFP-198 conidia can be used as a multi-targeting biological control agent against sucking agri- cultural pests, such as whiteflies and mites.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.461-474
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• 2004

The purpose of this study was to assess some biological activities of lipopolysaccharides (LPSs) from P. intermedia and P. nigrescens. LPS was prepared by the standard hot phenol-water method. NO production was assayed by measuring the accumulation of nitrite in culture supernatants. $TNF-{\alpha}$ production was determined by enzyme-linked immunosorbent assay. Western blot analysis of iNOS and analysis of reverse transcription (RT)-PCR products were carried out. LPS from P. intermedia demonstrated higher KDO content than those from two stains of P. nigrescens. LPSs from P. intermedia and P. nigrescens were mitogenic for spleen cells of BALB/C mouse. The present study clearly shows that LPSs from P. intermedia and P. nigrescens fully induced iNOS expression and NO production in RAW264.7 cells in the absence of other stimuli. Moreover, LPSs from P. intermedia and P. nigrescens clearly induced $TNF-{\alpha}$ production in RAW264.7 cells. The biological activities of LPS from P. intermedia was found to be comparable to those of P. nigrescens LPS. The ability of LPSs from P. intermedia and P. nigrescens to promote the production of NO and $TNF-{\alpha}$ may be important in the pathogenesis of inflammatory periodontal disease.

• BMB Reports
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• v.31 no.5
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• pp.432-443
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• 1998

The poliovirus Sabin 1 strain has features that make it a particularly attractive live recombinant mucosal vaccine vehicle. Sabin 1 cDNA was manipulated to have multiple cloning sites and a viral specific 3C-protease cutting site at the N-terminal end of the polyprotein. The gene for the N-terminal 169 amino acids of the HIV-1 p24 was cloned into the multiple cloning site of the manipulated Sabin cDNA. A recombinant progeny virus was produced from HeLa cells when it was transfected with the RNA synthesized from the p24-Sabin chimeric cDNA. The recombinant progeny virus expresses substantial amounts of the HIV-1 p24 protein, which was clearly detected in the infected cell lysates and culture supernatants in Western blot experiments with rabbit anti-p24 serum and AIDS patients' sera. Differing from the Mahoney strain, the recombinant Sabin 1 poliovirus maintained the foreign gene stably during the subsequent passages. Replication capacity was about 1 to 1.5 log lower than that of the wild-type Sabin 1. Other physicochemical stability characteristics of the recombinant virus were similar to that of the wild-type Sabin 1. These results suggest that the manipulated Sabin 1 poliovirus can be used as a live viral vaccine vector for the development of mucosal vaccines.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.804-811
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• 2001

In many Gram-negative bacteria, autoinducers, such as N-acyl-L-homoserine lactone(acyl-HSL) and its derivative molecules, mediate the cell-density-dependnet expression of certain operons. The current study identified the autoinducers produced by Burkholderia cepacia G4, a trichloroethylene-degrading lagoon isolate, using TLC bioassays with Agrobacterium tumefaciens NT1(pDCI141E33) and Chromobacterium violaceum CVO26, and a GC-MS analysis. The ${R_f}\;and\;{R_t}$ values and mass spectra were compared with those of synthetic compounds. Based on the analyses, it was confirmed that G4 produces N-hexanoyl (C6)-, N-octanoyl (C8)-, N-decanoyl (C10)-, N-dodecanoyl (C12)-HSL, and an unknown active species. The integration of the GC peak areas exhibited a ratio of C8-HSL:C10-HSL:C12-HSL at 3:17:1 with C6-HSL and C10-HSL production at trace and micromolar levels, respectively, in the culture supernatants. Nutants partially defective in producing acyl-HSLs were also partially defective in the biosynthesis of an antibiotic substance. These results indicate that the autoinducer-dependent gene regulation in G4 is dissimilar to the clinical B. cepacia strains isolated from patients with cystic fibrosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.972-977
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• 1997

Conjugated dienoic derivatives of linoleic acid(CLA) are a series of positional and gemotric isomers of linoleic acid which are found naturally in food, mainly dietary products and breef. We studied the effects of CLA on the growth of tumor cells and the production of interleukin-1(IL-1) and interleukin-2(IL-2). CLA treatment markedly inhibited the growth of Yac-1 cells and sarcoma-180 cells by 99 and 82% to that of control, respectively, after four days of incubation at 37$^{\circ}C$. To elucidate the immunological mechanism of antitumor activity of CLA, spleen cells of Balb/c mouse were exposed to 31, 63, 125, 250 $\mu\textrm{g}$ of CLA per ml for 24 hrs at 37$^{\circ}C$. The culture supernatants of CLA-exposed spleen cells reduced the production of IL-1 and IL-2 in all of the test conditions. These results indicate that the anticarcino-genic effect of CLA was mediated by the other actions rather than the production of the Il-1 or IL-2. We suggest that CLA might have an antiinflammatory effect in part due to its inhibitory action on the production of IL-1.

• Journal of Acupuncture Research
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• v.34 no.1
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• pp.11-21
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• 2017

Objectives : In this study, we investigated the anti-inflammatory and anti-oxidative effects of MOK, a pharmacopuncture medicine, in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. Methods : Peritoneal macrophages were isolated from ICR mice. Primary macrophages were treated with MOK extract (1.25, 2.5, 5, 10, and 20 mg/ml) for 30 min and then stimulated with LPS ($1{\mu}g/ml$) for the indicated times. Cytotoxicity was measured using MTT and LDH assays. Nitric oxide (NO) production in culture supernatants was measured using the Griess assay. The mRNA expression of iNOS, COX-2, proinflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$, and IL-6) and antioxidant enzymes (HO-1 and MnSOD) was measured by RT-PCR. Results : Treatment with MOK extract (2.5, 5, and 10 mg/ml) significantly decreased LPS-induced NO production in peritoneal macrophages through inhibition of iNOS expression. The expression of COX-2, TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 mRNA was also decreased in LPS-stimulated macrophages upon treatment with MOK extract. MOK treatment also increased the expression of HO-1 and MnSOD mRNA in macrophages. Conclusion : These results indicate that MOK exerts anti-inflammatory and antioxidant effects by regulating the transcription levels of inflammatory mediators and antioxidant proteins in activated macrophages.