• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.19-29
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• 2010

Phytoncide, essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Candida albicans, which is a commensal colonizer of the mucous membranes but has become an opportunistic pathogen. C. albicans was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its optical density, cell viability and morphology. As concentrations of phytoncide added to the culture medium increased, optical density and cell viability of C. albicans decreased. Minimum inhibitory concentration of phytoncide for C. albicans was observed to be 0.25%, and minimum fungicidal concentration was 0.5%. Numbers of morphologically atypical cells with electron-dense cytoplasm and granules and increased with increasing concentration of the phytoncide. At higher concentrations of phytoncide, compartments and organelles in the cytoplasm became indistinguishable. The overall results indicate that the phytoncide used for this study has a strong antimicrobial activity against C. albicans. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral candidiasis.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.180-192
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• 2017

The purpose of this study is to investigate the antioxidative and antimicrobial activities of sourdough fermented with the lactic acid bacteria (LAB) isolated from sliced radish kimchi. According to 16S rRNA gene sequence analysis, the isolated lactic acid bacteria were categorized as Leuconostoc dextranicum SRK03, Lactobacillus brevis SRK15, Pediococcus halophilus SRK22, Lactobacillus acidophilus SRK30, Lactobacillus plantarum SRK38, Leuconostoc citreum SRK 42, and Lactobacillus delbrueckii SRK60 with sequence similarity of 99%. After fermentation with L. dextranicum SRK03, L. acidophilus SRK30, L. plantarum SRK38 or L. delbrueckii SRK60 and Saccharomyces cerevisiae KCTC 7246 at $30^{\circ}C$ for 24 h LAB and yeast in sourdough were present at levels of $10^9$ and $10^7CFU/g$, respectively. In particular, the titratable acidity and ethanol and exopolysaccharide contents of sourdough fermented with L. dextranicum SRK03 were also significantly (P < 0.05) higher than those of sourdough fermented with L. acidophilus SRK30, L. plantarum SRK38, or L. delbrueckii SRK60. The sourdough fermented with L. dextranicum SRK03 and L. acidophilus SRK30 showed not only good DPPH radical-scavenging capacity but anti-lipid peroxidation activity. In addition, the viable counts of Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 in sourdough during storage for 5 days at $25^{\circ}C$ were significantly (P < 0.05) lower than those of pathogenic bacteria in the control group due to the organic acids and bacteriocin produced by L. acidophilus SRK30 strain.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.444-454
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• 2016

Sixteen lactic acid bacterial strains were isolated from silage and cow dung samples, and characterized to identify their potential as silage additives. They were identified as the members of the genera Lactobacillus, Enterococcus, and Weissella, and clustered into nine groups based on the sequences of the genes for 16S rRNA, RNA polymerase alpha subunit, 60-kDa heat shock protein, and phenylalanyl-tRNA synthase alpha subunit. Among them, the three strains which were genetically similar to L. plantarum showed the fastest growth and pH decrease in MRS and rye extract media, the highest numbers of available carbohydrates, and the widest ranges of pH, temperature, and salinity for growth. In addition, they showed no amplified DNA products in the PCR examination targeting the genes for the production of biogenic amines, and the MRS media where they had been cultured showed relatively high inhibition effect against the growth of silage-spoiling microorganisms, including fungi, yeast, and clostridia. The results suggest that these strains are good candidates for silage additives. However, the rye extract media where the lactic acid bacteria had been cultured had no effect on or stimulated the growth of the silage-spoiling microorganisms, and the causes must be established for the practical use of the lactic acid bacteria as silage additives.

• Journal of Life Science
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• v.20 no.10
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• pp.1544-1548
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• 2010

Moxifloxacin (MF) - resistant mutants of Mycoplasma hominis (M. hominis) were generated by stepwise selection in increasing concentrations of MF, and six strains of MF resistant M. hominis mutants - M1, M4, M8, M16, M32, and M64 - in which MICs of MF were 0.5, 4, 8, 16, 32, 64 ${\mu}g$/ml, respectively, were generated. Compared to the sequence of M. hominis PG21, all mutants harbored amino acid substitutions of Arg-163 Thr in GyrA, and Pro-445 Gln in ParE. While the concentrations were getting higher, an additional amino acid substitution was found at Ser-153 Lys in GyrA (${\geq}4{\mu}g/ml$), Ser-91 Ile in ParC (${\geq}16{\mu}g/ml$), and Val-450 Phe (${\geq}64{\mu}g/ml$) in GyrB. These substitutions seem to have an impact on resistance to MF, and GyrB change was found only in the highest concentration and seems to be associated with high-level resistance to MF. This, as far as we know, is the first description of a relationship between MF resistance phenotype and genotype.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.306-312
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• 2016

Gargle solution has typically been used for the prevention of oral infectious disease such as dental caries and periodontitis. However, the use of most gargle solutions is controversial in application for children because some gargle solutions have harmful side effects. Electrolyzed water is generated by passed an electric current and has antimicrobial activity. The purpose of this study was to investigate and compare the efficacy of electrolyzed water in various conditions for eliminating cariogenic bacteria. Electrolyzed water was generated by a platinum electrode in the presence of sodium chloride at various concentrations. Streptococcus mutans and Streptococcus sobrinus were cultivated into a brain heart infusion broth. After harvesting planktonic bacteria, the pellets were treated with the electrolyzed water and commercial gargle solutions and plated on a mitis-salivarius agar plate. Also, the anti-biofilm activity of the electrolyzed water and commercial gargle solutions was investigated after biofilm formation of S. mutans and S. sobrinus. The bacteria in the biofilm were plated onto a mitis-salivarius agar plate. The plates were incubated, and the colony forming unit was measured. The electrolyzed water containing sodium chloride showed significant antibacterial activity against S. mutans and S. sobrinus as well as some gargle solutions. Furthermore, the electrolyzed water had more disruptive effect on the biofilm of S. mutans and S. sobrinus and killed more bacteria in the biofilm than commercial gargle solutions. The results demonstrate that electrolyzed water may be a useful gargle solution for prevention of dental caries.

• Tuberculosis and Respiratory Diseases
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• v.65 no.2
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• pp.147-151
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• 2008

Non-resolving or slowly resolving pulmonary infiltrates in spite of administering adequate antimicrobial therapy are a clinical diagnostic challenge for physicians. The rate of radiographic resolution varies with the patients' age, the underlying comorbidities, the extent of radiographic involvement, the functional status and the causal pathogens. It is important to differentiate non-resolving or slowly resolving bacterial pneumonia from other uncommon infectious pneumonias or malignancies that require invasive diagnostic techniques to confirm the diagnosis. Bronchioloalveolar carcinoma can present with various clinical and radiographic features. Unfortunately, the radiographic similarity of consolidative BAC to pneumonia often leads to an incorrect diagnosis of pneumonia and possibly significant delays in obtaining appropriate diagnostic studies. We describe here a case of a mixed adenocarcinoma and bronchioloalveolar carcinoma that was initially diagnosed as pneumonia due to the consolidation pattern on the radiography and the patient's initial improvement with antibiotic treatment.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.141-149
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• 2017

This study was to investigate the sanitary microbiological aspects of Cheonho Reservoir and its antibiotic resistance in the natural environment to contribute to the public healthcare improvement. Groups of coliforms, were counted at three sites of the Cheonho Reservoir in July and September 2013, and the isolates were identified according to the water pollution process test standards. Antibiotic resistance was evaluated using the Korea National Institute of Health's standard antibiotic susceptibility test. The average coliform counts in Cheonho Reservoir were $2.0{\times}10^3CFU/mL$, 41% of which were identified as Escherichia coli(E. coli). Antibiotic resistance rate in E. coli isolated from Cheonho reservoir was highest in Ampicillin 31.3%, Ticarcillin 25.0%, Cefaxolin and Cefoxitin 18.8% respectively. Convergence multiple resistance patterns, 38,5% presented resistance to 4 durgs, 6 drugs resistance were 7.7%. The more than 2 drugs resistance were 92.3%. Cheonho Reservoir is a public park that accessible to the citizens, further convergence studies are needed to develop sanitary microbiological management practices and study antibiotic resistance of the reservoir.

• KSBB Journal
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• v.20 no.4
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• pp.285-290
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• 2005

Benzophenanthridine alkaloids - sanguinarine, chelirubine, macarpine, and chelerythrine are produced from Eschscholtzia californica (Californica Poppy, used as a sedative by Native Americans) and most of them are derived from dihydrosanguinarine. The properties of sanguinarine are the basis of its antimicrobial activity and its use in chemosurgery and skin cancer excision. For overproduction of sanguinarine from E. californica, yeast extract was used as elicitor and the elicited cell's metabolites were checked. Sanguinarine production was increased intracelluarly about 8 times in the cell and 5 times extracelluarly. We have peformed proteomic analysis of proteins sequentially extracted from E. califormica suspended cells which were cultured with elicitor, an increase of spot intensity was seen at 24 hours following elicitation. These proteins were separated by two-dimensional electrophoresis (2-DE). We found several spots that were expected to be related to benzophenanthridine alkaloids production by comparing the production profiles of metabolites such as sanguinarine. These results demonstrate the use of metabolite analysis as a tool for detecting target proteins related to metabolites production pathway.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.1-8
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• 2008

It is well known that many antimicrobial proteins in saliva interact with each other. The purpose of the present study was to investigate the interactions of lysozyme with peroxidase in the aspects of enzymatic activity in vitro. The interactions of lysozyme with peroxidase were examined by incubating hen egg-white lysozyme(HEWL) with bovine lactoperoxidase(bLP). The influence of peroxidase system on lysozyme was examined by subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Peroxidase activity was determined with an NbsSCN assay. The Wilcoxon signed rank test was used to analyze the changes of enzymatic activities compared with their controls. bLP at physiological concentrations enhanced the enzymatic activity of HEWL(P < 0.05) and its effect was dependent on the concentration of peroxidase. However, HEWL did not affect the enzymatic activity of bLP. Thiocyanate did not affect the enzymatic activity of HEWL, either. The addition of potassium thiocyanate and hydrogen peroxide did not lead to additional enhancement of the enzymatic activity of HEWL. The changes of hydrogen peroxide concentration in the peroxidase system did not affect the enzymatic activity of HEWL. Collectively, despite an in vitro nature of our study, the results of the present study provide valuable information on the interactions of lysozyme and peroxidase in the aspects of enzymatic activity in oral health care products and possibly in the oral cavity.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.69-79
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• 2003

The purpose of this present study was to develop a new way of self-curing acrylic resin, using commercially available polyphosphate, Calgon, which is known to be antimicrobial and safe. For the study, polyphosphate(polyP) was blended with acrylic powder and devided into four groups as follows: no polyP(control), 1% polyP, 2% polyP, and 3% polyP. For the experiment, Streptococcus mutans GS5, Streptococcus sobrinus 6715, Streptococcus gordonii G9B and Challis, Porphyromonas gingivalis 2561, and Candida albicans ATCC 90027 were used. Resin specimens in each group were tested in vitro for the purpose of investigating the effect of polyP on the microbial attachment, growth and hydrophobicity of the resin surface. The results were as follows. 1. PolyP added to the acrylic resin decreased attachment of S. mutans GS5, S. sobrinus 6715, S. gordonii G9B. The greater binding inhibition was found in acrylic resin polymerized with polyP at higher concentrations. 2. The addition of polyP to acrylic resin failed to significantly affect the growth of the tested microorganisms. 3. The addition of polyP to acrylic resin seemed to reduce hydrophobicity of the acrylic resin. PolyP in acrylic resin does not seem to exert a direct antibacterial activity, but rather inhibit attachment of oral bacteria, especially mutans streptococci to saliva-coated acrylic resin. The acrylic resin reduces attachment of streptococci may be due to the decreased hydrophobicity caused by polyP added to the resin. PolyP may be included to acrylic resin to inhibit dental caries which often occurs when removable acrylic resin appliance is placed.