• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.113-113
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• 2018

Endophthalmitis is a disease that causes ocular inflammation and has a catastrophic effect on eyesight. Recent studies show that Enterococcus faecalis is rapidly increasing causative bacterium of endophthalmitis. It is predicted that the increased endophthalmitis by E. faecalis is presumable due to the high resistance of E. faecalis to moxifloxacin (MFX), which is a common antibiotic used for eye drop. Because of the need for therapeutic agents to overcome this problem, this study sought to explore the feasibility of developing a combination therapy using Orostachys japonicus. The ethylacetate fraction of O. japonicus (OJA) used in this study. Antimicrobial activity was tested 13 E. faecalis strains including one E. faecalis standard strain, eight clinically isolated E. faecalis strains and four quinolone resistant E. faecalis strains using CLSI antibiotic susceptibility test method. Minimal Inhibitory Concentration (MIC) of OJA was confirmed to be $500{\mu}g/ml$ for all 13 strains. Then we tested for the synergistic effect of OJA to MFX using checkboard test method. The MIC of MFX was $0.25{\mu}g/ml$ for the standard strain and 8 for the clinical isolates, and $16{\sim}64{\mu}g/ml$ for the quinolone - resistant strains. When OJA was mixed with MFX, no synergistic effect was observed in all strains, but the antibacterial activity of OJA remained unchanged. Most ocular other strains can be removed by MFX except the MFX resistant E. faecalis, which can be removed by OJA in combination therapy. Therefore, OJA can be a potential candidate for the combined treatment endophthalmitis.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.43-49
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• 2010

Enterococcus faecalis, a gram-positive bacterium, has been implicated in endodontic infections, particularly in chronic apical periodontitis. Proinflammatory cytokines, including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), are involved in the pathogenesis of these apical lesions. E. faecalis has been reported to stimulate macrophages to produce TNF-$\alpha$. The present study investigated the mechanisms involved in TNF-$\alpha$ production by a murine macrophage cell line, RAW 264.7 in response to exposure to E. faecalis. Both live and heat-killed E. faecalis induced high levels of gene expression and protein release of TNF-$\alpha$. Treatment of RAW 264.7 cells with cytochalasin D, an inhibitor of endocytosis, prevented the mRNA up-regulation of TNF-$\alpha$ by E. faecalis. In addition, antioxidant treatment reduced TNF-$\alpha$ production to baseline levels. Inhibition of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase also significantly attenuated E. faecalis-induced TNF-$\alpha$ expression by RAW 264.7 cells. Furthermore, activation of NF-${\kappa}B$ and AP-1 in RAW 264.7 cells was also stimulated by E. faecalis. These results suggest that the phagocytic uptake of bacteria is necessary for the induction of TNF-$\alpha$ in E. faecalis-stimulated macrophages, and that the underlying intracellular signaling pathways involve reactive oxygen species, ERK, p38 MAP kinase, NF-${\kappa}B$, and AP-1.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.218-224
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• 2011

Lactic acid bacteria (LAB) OA18 was isolated from yogurt prepared by using Kefir Grain as a starter. The OA18 strain was a Gram-positive, cocci-type bacterium, and able to grow anaerobically with $CO_2$ production. The OA18 strain grew well on MRS broth supplemented with 50 mM arginine at $30-37^{\circ}C$ and pH of 7.0-9.0. The optimum temperature and pH for growth are $37^{\circ}C$ and pH 7.0. The isolate fermented ribose, D-glucose, cellobiose, D-trehalose, but not L-xylose, D-melibiose, and inositol. The 16S rRNA gene sequence of the isolate showed 99.8% homology with the Enterococcus faecalis 16S rRNA gene (Access no. AB012212). Based on the biochemical characteristics and 16S rRNA gene sequence analysis data, it was identified and named as E. faecalis OA18. The E. faecalis OA18 strain showed a high ornithine-producing capacity in the presence of arginine and also showed an antimicrobial activity against Streptomyces strains such as Streptomyces coelicolor subsp. Flavus, S. coeruleorubidus, S. coeruleoaurantiacus, S. coelicolor, S. coeruleoprunus. The cell growth of E. faecalis OA18 strain was maintained in MRS broth with a NaCl concentration of 0-7%.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.916-924
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• 2017

Eighty-five Enterococcus faecalis isolates collected from animals (40 isolates), meju (a Korean fermented soybean product; 27 isolates), humans (10 isolates), and various environmental samples (8 isolates) were subjected to multilocus sequence typing (MLST) to identify genetic differences between samples of different origins. MLST analysis resulted in 44 sequence types (STs), and the eBURST algorithm clustered the STs into 21 clonal complexes (CCs) and 17 singletons. The predominant STs, ST695 (21.1%, 18/85) and ST694 (9.4%, 8/85), were singletons, and only contained isolates originating from meju. None of the STs in the current study belonged to CC2 or CC9, which comprise clinical isolates with high levels of antibiotic resistance. The E. faecalis isolates showed the highest rates of resistance to tetracycline (32.9%), followed by erythromycin (9.4%) and vancomycin (2.4%). All isolates from meju were sensitive to these three antibiotics. Hence, MLST uncovered genetic diversity within E. faecalis, and clustering of the STs using eBURST revealed a correlation between the genotypes and origins of the isolates.

• Restorative Dentistry and Endodontics
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• v.40 no.4
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• pp.306-313
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• 2015

Objectives: Molecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection. Materials and Methods: Among 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined. Results: Identified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function. Conclusions: In vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1335-1340
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• 2007

β-Ketoacyl acyl carrier protein synthase (KAS) III is a particularly attractive target in the type II fatty acid synthetic pathway, since it is central to the initiation of fatty acid synthesis. Enterococcus faecalis, a Grampositive bacterium, is one of the major causes of hospital acquired infections. The rise of multidrug-resistant of most bacteria requires the development of new antibiotics, such as inhibition of the KAS III. In order to block the fatty acid synthesis by inhibition of KAS III, at first, three dimensional structure of Enterococcus faecalis KAS III (efKAS III) was determined by comparative homology modeling using MODELLER based on x-ray structure of Staphylococcus aureus KAS III (saKAS III) which is a gram-positive bacteria and is 36.1% identical in amino acid sequences with efKAS III. Since His-Asn-Cys catalytic triad is conserved in efKAS III and saKAS III, substrate specificity of efKAS III and saKAS III and the size of primer binding pocket of these two proteins are expected to be similar. Ligand docking study of efKAS III with naringenin and apigenin showed that naringenin docked more strongly with efKAS III than apigenin, resulting in the intensive hydrogen bond network between naringenin and efKAS III. Also, only naringenin showed antibacterial activity against E. faecalis at 256 μg/mL. This study may give practical implications of flavonoids for antimicrobial effects against E. faecalis.

• Biomedical Science Letters
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• v.20 no.1
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• pp.25-31
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• 2014

Atopic dermatitis (AD) is an inflammatory, relapsing, chronic skin disease and lesions in AD are frequently colonized with Staphylococcus aureus (S. aureus). Activation of T cells and IgE production by staphylococcal enterotoxins B (SEB) plays a crucial role in the pathogenesis of AD. Enterococcus faecalis (E. faecalis) is a nonpathogenic bacterium and produces the probiotic products that have been shown to have inhibitory effects on inflammatory responses. In present study, we carried out to assess the anti-inflammatory role of lyzed E. faecalis against the damaging effects of SEB on AD related immune responses. Furthermore, we attempted to determine whether the co-cultured lyzed E. faecalis can influence the colonization of S. aureus. As a result, we identified the effect of E. faecalis lysate as a potent therapeutic agent for atopic dermatitis (AD). E. faecalis lysate reduces the productions of total IgE and cytokines of AD-related immune cells in response to SEB stimulation. The proliferation of S. aureus was also inhibited by E. faecalis lysate. In conclusions, E. faecalis lysate may improve the skin-defense system disturbed by atopic condition, and may prevent subsequent secondary infection of S. aureus and development of AD.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.621-621
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• 2003

I. Objectives In order to examine the immunoresponse of host cells to Enterococcus faecalis, this in vitro study monitored the production of Interleukin-2(IL-2), Interleukin-4(IL-4) and Transforming growth $factor-{\beta}1(TGF-{\beta}1)$ in human lymphocytes. II. Materials and methods Enterococcus faecalis(ATCC29212) strains were used in this study. Strains were grown in 1-liter cultures in 85% N2-10% H2-5% $CO_2$chamber for 3 days at $37^{\circ}C$. The medium used was 3.7% brain heart infusion broth. Bacterial cells harvested from 1-liter cultures were washed, suspended in 20ml of phosphate-buffered saline(PBS). Suspensions of bacterial cells were disrupted by sonication on ice for 5 min. Protein concentration was determined by the Bicinchoninic acid(BCA) protein assay.(omitted)

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.68-73
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• 2016

Lactic acid bacteria showing both protease activity and the capacity to produce casein phosphopeptide (CPP) were isolated from Korean kimchi, a traditional food made from fermented vegetables. Among the 450 strains of isolated lactic acid bacteria, the strain MG-379 showed high protease activity and the highest ability to produce CPP. Characterization results showed that MG-379 was gram-positive and measured $0.6-0.8{\mu}m$ in diameter. DNA sequencing of MG-379 and comparison with other sequences using BLAST revealed a 100% identity with the sequence of Enterococcus faecalis. However, MG-379 showed a higher CPP-producing ability than E. faecalis KCCM 40450. Accordingly, MG-379 was newly named as E. faecalis MG-379. Amount of free calcium liberated by CPPs was 2227.5 and 1151.6 mg/kg for E. faecalis MG-379 and E. faecalis KCCM (control), respectively.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.391-402
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• 2018

The aim of the present work was to provide information about Enterococcus strains isolated from pre-packaged chicken samples in Ankara (Turkey), focusing on their prevalence, phenotypic and genotypic characteristics, and antibiotic resistance. We report the first study on the occurrence of antibiotic resistant enterococci in pre-packaged chicken samples in Ankara. A total of 97 suspicious enterococcal isolates were identified from 122 chicken samples. All isolates were identified to species level by phenotypic and molecular methods. In the 16S rDNA sequence analysis, Enterococcus faecium (61.85%) and Enterococcus faecalis (38.15%) were found to be the most frequently detected Enterococcus spp. Of the 97 isolates tested for hemolytic activity, 12.37% enterococcal strains were ${\beta}$-hemolytic. ${\beta}$-Hemolysin was most prevalent among E. faecium (58.33%) compared to E. faecalis (41.66%). Disk diffusion method was used for determining of antibiotic resistance. The analysis of the antimicrobial resistance of the 97 Enterococcus isolates revealed that the resistance to kanamycin (98.96%), rifampicin (80.41%) and ampicillin (60.82%) was most frequent. Furthermore, resistance to erythromycin (38.14%) and ciprofloxacin (34.02%) was also observed. The frequencies of resistance to tetracycline (9.27%), penicillin G (8.24%), and chloramphenicol (3.09%), gentamicin (2.06%) and streptomycin (1.03%) were low. None of the isolates was resistant to vancomycin. Multi-drug resistance was found in 97.93% of Enterococcus strains. E. faecium strains showed a more resistant phenotype than E. faecalis strains according to the antibiotic resistance levels. The results of this study indicated that chicken meat is a potential reservoir for the transmission of antibiotic resistance from animals to humans.