• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.264-269
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• 2012

Recently, we reported that the synthetic Coprisin analog peptide 9-mer dimer CopA3 (consisted of all-L amino acid sequence) was designed based on a defensin-like peptide, Coprisin isolated from Copris tripartitus. The 9-mer dimer CopA3 (L-CopA3) had antibacterial activity and induced apoptosis in human leukemia cells via a caspase-independent pathway. In this study, all of amino acid sequences of L-CopA3 were modified to all D-form amino acids (DCopA3) to develop a more effective antimicrobial peptide. We investigated whether D-CopA3 had antimicrobial activities against pathogenic microorganisms and pro-apoptotic effects in human leukemia cells (U937, Jurkat, and AML-2). The synthetic peptide D-CopA3 had antimicrobial activities against various pathogenic bacteria and yeast fungus with MIC values in the 4~64 ${\mu}M$ range. Moreover, D-CopA3 caused cell growth inhibition, and increased the chromosomal DNA fragmentation and the expression of inflammatory cytokines, TNF-${\alpha}$ and IL1-${\beta}$, transcripts in human leukemia cells. The all-D amino acid peptide DCopA3 proved as effective as the L-CopA3 reported previously. These results provide the basis for developing D-CopA3 as a new antibiotic peptide.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.241-250
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• 1987

A total 64 strains of Escherichia coli including 38 strains of urinary tract infection and 26 strains from other clincal sources were studied for several properties related to the virulence markers of organisms. Urinary isolates(76.3%) showed higher frequency of mannose resistant hemagglutination(MRHA) wi th human erythrocytes(A type, $Rh^+$) than the strains of control group isolated from other sources(34.6%). Seventeen strains(44.4%) of urinary isolates and 2 strains(7.7%) of control group showed hemolysis on blood agar plate. There was no significant difference in MIC's of 23 drugs between both groups of urinary isolates and control group. But they showed high frequency of resistance to ampicillin, carbenicillin, piperacillin, kanamycin, and trimethoprim, but were very susceptible to cefotaxime, moxalactam, ceftizidime, imipenem, and norfloxacine. Fourteen strains(36.8%) of urinary isolates and 10 strains(38.5%) of control group showed conjugally transferable resistance conferred to R plasmids. The urinary isolates carried one or more to 6(mean 3.4) plasmids of approximate molecular weight ranged 3.1 to 94 megadalton(Mdal) and strains of control group carried 2 to 5(mean 3.8) plasm ids of size ranged 3.6 to 130 Mdal. The size of conjugally transferable R plasmid identified with transconjugants ranged 32 to 130 Mdal.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.95-99
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• 2018

In insect defense system, antimicrobial peptides (AMPs) are one of important biological molecules to survive in a variety of environments. Insect can synthesize AMPs to protect against invading pathogens in humoral immune response. Taking more advantage of biological antimicrobial molecules, we report antibacterial activity of two cecropin type peptides, cecropin and moricin, isolated from the silkworm against four salmonella species. In this work, we purified antimicrobial candidate peptides (AMCP) from the extracts of immune challenged silkworm larval hemolymph by two-step chromatographic purification procedure, cation exchange and gel permeation chromatography. The molecular weights of purified peptides were estimated to be about 4 ~ 5 kDa by Tricin SDS-PAGE analysis, and identified as silkworm cecropin and moricin by NCBI BLAST homology search with their N-terminal amino acid sequences. As antibacterial activity assay, the purified peptides showed stronger antibacterial activity against Salmonella pathogens with an MIC value of $1{\sim}4{\mu}g/mL$. Therefore two cecropin type peptides purified from the silkworm will be valuable potential materials for development of new natural antibiotics.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.8.1-8.7
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• 2019

Objectives: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. Materials and Methods: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). Results: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. Conclusions: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.145-185
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• 2007

A resident registration number is used to confirm and prove his/her identity in a government/non-governmental agency. It is a essential requirement to become the registered member on internet website in Korea. It is serious problem that the resident registration number and name are outflowed in internet and misused by others. So the MIC(Ministry of Information and Communication) in Korea plans and operates the identification system using I-PIN that integrate 5 alternative methods of resident registration number. In this paper, we analyze the problem about the method of 5 I-PIN services and show the security analysis on the implementation vulnerabilities of I-PIN services. we also analyze 17 websites that provides identification system using I-PIN. Finally, we analyze the overall problem of I-PIN service and propose the countermeasure about the problem.

• Korean Journal of Pharmacognosy
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• v.53 no.4
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• pp.213-225
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• 2022

Schisandra chinensis is widely known to regulate fatigue recovery, lowering blood pressure, and contains several bioactive compounds such as schizadran. In this study, we obtained basic data for the development of health food by measuring the schizandrin content, antioxidant activity, anti-inflammatory, antibacterial activity, and enzyme activity of the hot water extract (SCW) and 40% ethanol extract (SCE) of S. chinensis grown in Sunchang-gun, Korea. Schizandrin content was measured as 7.87 ± 0.01 mg/g for SCW and 10.38 ± 0.05 mg/g for SCE. SCE had higher DPPH and ABTS radical scavenging activity than SCW, and the total polyphenol and flavonoid contents were also higher. Both SCW and SCE (500 ㎍/mL) exhibited more than 55% protective effects against oxidative stress in HepG2 cell lines. Anti-inflammatory efficacy was assessed using RAW 264.7 and Caco-2 cells and both SCW and SCE do not have cytotoxic effects. Anti-inflammatory results showed concentration-dependent NO activity and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) inhibition. The antibacterial activity increased with increasing dose concentrations of SCW and SCE, and the MIC was 25 mg/mL for L. monocytogenes, S. typhimurium, and 75 mg/mL for H. pylori. In addition, amylase and protease enzyme activity was observed in both SCW and SCE.

• Journal of Pharmacopuncture
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• v.26 no.3
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• pp.265-275
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• 2023

Objectives: The aim of this study was to evaluate the effect of fruit juices on Multi-Drug Resistant (MDR) bacterial pathogens involved in Urinary Tract Infections (UTIs) and Sexually Transmitted Infections (STIs) among tribal women in the district Anuppur, Madhya Pradesh, India. Methods: Fresh juices of lemon (Citrus limon), amla/Indian gooseberry (Phyllanthus emblica), pineapple (Ananas comosus), mosambi/sweet lime (Citrus limetta), orange (Citrus sinensis), kiwi (Actinidia deliciosa), and pomegranate (Punica granatum) fruits were evaluated for in vitro antibacterial activity against bacterial pathogens involved in UITs and STIs among tribal women. Physico-chemical analysis of fresh fruits was also carried out by measuring the pH, moisture, protein, fat, crude fibre, carbohydrate, and ascorbic acid content. Results: Lemon and amla juice showed better antibacterial activity against the pathogens as compared to other juices. MIC results fruit juices against UTIs and STIs pathogens vary depending on the specific pathogen and juice chemical constituents. The physico-chemical analysis showed that the moisture content was highest in mosambi (90%), followed by orange (87%). Ascorbic acid content was found highest in amla (540 mg/100 g), followed by kiwi (90.3 mg/100 g). Pomegranate showed highest concentration of carbohydrate (15.28 g/100 g), fat (1.28 g/100 g), and protein (1.65 g/100 g). Lemon juice had lowest pH of 2.20, followed by amla 2.67. Conclusion: The lemon juice showed highest antibacterial activity against MDR bacterial pathogens involved in UTIs and STIs among tribal women in district Anuppur, Madhya Pradesh, India. The low pH of lemon may be responsible for its high antibacterial activity as compared to other juices.

• The Journal of Internal Korean Medicine
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• v.45 no.2
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• pp.167-175
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• 2024

Hospital-acquired bacterial infections, including vancomycin-resistant enterococci (VRE) infection (MIC: 32 mcg/ml), are common. We describe the case of a 63-year-old female patient with subarachnoid hemorrhage and VRE infection treated with Jashin-bowon-tang and Samhuang-sashim-tang for 57 days and 22 days, respectively. The therapeutic effect was assessed weekly via culture, color and viscosity of pus from a coccyx sore, and C-reactive protein (CRP). Vital signs were checked four times a day. Seventeen days after treatment, VRE was not colonized in patient and color and viscosity of pus, CRP and vital sign were improved. This case report suggests that Jashin-bowon-tang and Samhuang-sashim-tang might be an alternative option for VRE infection patients reducing the need for extended isolation periods and speeding up recovery times.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.93-101
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• 2012

We analyzed mupirocin resistance rates among staphylococcal isolates collected from a Korean hospital in 2003 (100 isolates), 2005 (195 isolates), 2006 (151 isolates), and 2009 (112 isolates). In Staphylococcus aureus, rates of high-level mupirocin resistance (MIC, minimal inhibitory concentration ${\geq}512{\mu}g/ml$) decreased and did not appear since 2005. In contrast, low-level mupirocin resistance (MIC $8-256{\mu}g/ml$) was not detected in 2003 and 2005 but its rates later increased to 6.9% in 2009. Total resistance rates of coagulase-negative staphylococci (CNS) were significantly higher than those of S. aureus. The rates of high-level resistance of CNS increased from 16.0% in 2003 to 31.5% in 2009. The rate of low-level resistance of CNS was 8.0% in 2003 and around 11% later. In all high-level resistant isolates, the ileS-2 gene was detected. All low-level resistant isolates contained the known V588F mutation in ileS gene. Previously unknown mutations such as V458G in S. aureus and D172A, Y490H and I750V in CNS were identified additionally. One S. aureus isolate with high-level resistance was resistant to oxacillin and several topical antibiotics commonly used for the treatment of skin infection. Ten S. aureus isolates with low-level resistance were also resistant to all of these antibiotics except fusidic acid. CNS isolates with high-level (61 isolates) and low-level resistance (27 isolates) exhibited significantly higher resistance rates to these antibiotics than mupirocin-susceptible CNS isolates (167 isolates). In conclusion, prevention of the emergence of mupirocin resistance is necessary for the effective treatment of skin infection by staphylococci.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.561-574
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• 2000

Poly-P has been used to prevent decomposition of foods and has been shown to have inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly-P on the growth of Porphyromonas endodontalis, a gram negative obligate anaerobic rod, endodontopathic bacterium. P. endodontalis ATCC 35406 was in BHI broth containing hemin and vitamin K with or without poly-P. Inhibitory effect of each poly-P which was added at the beginning(lag phase) or during(exponential phase) the culture, MIC(minimum inhibitory concentration) was determined by measuring the optical density of the bacterial cell at 540nm. Viable cell counts were measured to determined whether poly-P has a bactericidal effect. Leakage of intracellular nucleotides from P. endodontalis was determined at 260nm and morphological change of P. endodontalis was observed under the TEM(transmission electron microscope). Binding of 32P-labeled poly-P to P. endodontalis was examined. SDS-polyacrylamide gel electrophoresis and zymography were performed to observe the changes in protein and enzyme profiles of P. endodontalis, respectively. The results from this study were as follows : 1. The minimal inhibitory concentration(MIC) of poly-P to P. endodontalis appeared to be 0.04~0.05%. 2. Poly-P added to the P. endodontalis culture during the exponential phase of P. endodontalis was as much effective as poly-P added at the begining of the culture, suggesting that the antibacterial effect of poly-P is not much dependent on the initial inoculum size of P. endodontalis. 3. Poly-P are bactericidal to P. endodontalis, demonstrating the decrease of the viable cell counts. 4. Intracellular nucleotide release from the P. endodontalis, was not increased in the presence of poly-P and was not reversed by the addition of divalent cations like $Ca^{2+}$ and $Mg^{2-}$. 5. Under the TEM, it was observed that fine electro-dense materials were prominent in the poly-P grown P. endodontalis, appearing locally in the cell, and the materials were more abundant and more dispersed in the cell as the incubation time with poly-P increased. In addition, highly electron dense granules accumulated in many poly-P grown cells, most of which were atypical in their shape. 6. Binding of 32P-labeled poly-P to P. endodontalis appeared to be 32.8 and 45.5 and 53.4% at 30 minutes, 1 hours and 2 hours, respectively. 7. In the presence of poly-P. the synthesis of proteins with apparent molecular masses of 25, 27, 35, 45 was lost or drastically decreased whereas expression of a protein with an apparent molecular mass of 75 was elevated. 8. Proteolytic activity of P. endodontalis was decreased by poly-P. The overall results suggest that use of poly-P may affect the growth of P. endodontalis, and the anti-bacterial activity of poly-P seems largely bactericidal. Changes in shape, protein expression, and proteolytic activity of P. endodontalis by poly-P may be directly and indirectly attributed to the antibacterial effect of poly-P. Further studies will be needed to confirm the effect of poly-P.