• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.1-8
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• 2011

The antimicrobial effects of silver (Ag) ion or salts are well known. Recently, silver nanoparticle is attracting an interest in a wide variety of fields since it has been known to be safe and effective as an antimicrobial agent against a broad spectrum of microorganisms. Although silver nanoparticle has been applied to various kinds of products owing to its potent antimicrobial activity, the effects of silver nanoparticle on microorganisms and antimicrobial mechanism have not been revealed clearly. In this paper, we summarized the characteristics, antimicrobial activities and mechanisms, cytotoxicity and applicability of silver nanoparticle.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.113-117
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• 2003

In order to develop a antimicrobial agent, bamboo oil was extracted by high temperature suction from dired bamboo truk and then antimictobial activities against Trichophyton and Pityrosporum are investigated. 1. Bamboo oil showed the strongest antimicrobial effect on Trichophyton mentagrophytes > Epidermophyton floccusum > Trichophyton rubrun. Bamboo oil showed the strongest antimicrobial activity on Trichophyton mentagrophytes. 2. Bamboo oil showed the strongest antimicrobial effect on Pityroporum ovale 75 > Pityrosporum ovale 77. Bamboo oil showe the strongest antimicrobial activity on Pityroporum ovale 75.3 Antimicrobial effect in 50%-ethanol extracts of bamboo oil are similar to 100%-bamboo oil.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.154-161
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• 2017

An antimicrobial peptides-producing Bacillus strain CBS73 was isolated from fermented food (kimchi) that produces low-molecular-weight proteins with broad-spectrum antimicrobial activity. Our goal was to explore the therapeutic potential of antimicrobial substances produced by Bacillus species. Peptide CBS73 was purified from Bacillus subtilis subsp. subtilis with identity of 99.79%. It was found to be stable at pH 4.0-10.0 and temp $20-60^{\circ}C$. A protein band around 5.2 kDa was detected in tricine-SDS-PAGE and band was confirmed by MALDI-TOF test. Peptide CBS73 showed antimicrobial activity against MDR bacteria. The minimal inhibitory concentration (MIC) of peptide CBS73 for vancomycin-resistant S. aureus (VRSA), vancomycin resistant Enterococci (VRE) and Salmonella typhimurium ranged from $10-40{\mu}g/mL$. The antioxidant activity of peptide CBS73 was measured by DPPH scavenging, reducing power activity and total phenolic content. Cell viability and NO production result showed less cytotoxic effect upto $12{\mu}g/mL$. Peptide CBS73 could be a promising antimicrobial agent for clinical application.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.81-88
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• 2010

Objectives : Sophorae Radix (SR), the dried root of Sophorae Flavescens Aiton, has been used to treat atherosclerosis, arrhythma and skin diseases including scabies and eczema. The present study was examined to evaluate antimicrobial activities of SR extracts against oral microorganism. Methods : Antimicrobial properties of SR extracts were determined by agar diffusion method and minimum inhibitory concentration (MIC) against Streptococcus mutans, Streptococcus sobrinus and Actinomyces viscosus. Analysis of kurarinone from SR extracts was conducted using UPLC (Ultra Performance Liquid Chromatography). Results : The ethanolic extracts of SR showed stronger antimicrobial effect than methanolic extracts, while the aqueous extracts of SR had no activity. In addition, the higher content of kurarinone was found in ethanolic extracts than methanolic extracts. The purified kurarinone from ethanolic extracts showed potent antimicrobial activity with the MIC value of $3.9{\sim}7.8{\mu}g/m{\ell}$. Conclusion : An ethanolic extract of SR showed antimicrobial properties against several oral microorganisms, and kuranrinone contributed to antimicrobial action of SR. Thus, ethanolic extracts of SR or purified kurarinone should be beneficial for the preparation of the useful agent for treating oral disease including anticaries.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.1 s.60
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• pp.47-52
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• 2007

The antimicrobial properties of medium-chain ($C_{8-12}$) free fatty acids and their 1-monoglyceride derivatives against a wide range of microorganisms we well known. However, previous studies have been mainly focused on the antimicrobial activity against pathogenic bacteria and viruses causing diseases in human or domestic animals' infection. But, there have been few reports describing comprehensive surveys of antimicrobial effects against microorganisms in cosmetics. For a start of this study, we evaluated and compared the preservative activities of $C_8$ (glyceryl caprylate) and $C_{12}$(glyceryl laurate) 1-monoglyceride in cosmetic formulations. From the result, we found that both of them have very excellent preservative activity against bacteria, but less against fungi. And $C_8$ 1-monoglyceride was a little bit more effective than $C_{12}$ 1-monoglyceride. According to the test results to evaluate each antimicrobial activity of glyceryl caprylate towards 5 kinds of microorganisms used in preservation efficacy test in cosmetics, gram-positive bacteria S. aureus and yeast C. albicans were sensitive and mold A. niger was most tolerant to glyceryl caprylate. Therefore, we tried to improve the antimicrobial activity of glyceryl caprylate agianst mold such as A. niger so that we could make it used as a preservative for cosmetic products. As a result, we confirmed that the antimicrobial activity of glyceryl caprylate is much improved under acidic conditions in formulation. In addition, we found optimal combinations of glyceryl caprylate with other antimicrobial agents. Among tested 7 antimicrobial agent, methyparaben showed the highest preservative activity in combination with gglyceryl caprylate.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.120-127
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• 2020

The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) using plaque disclosing agent, 10 - 20 mM erythrosine, as a photosensitizer. Multispecies cariogenic biofilms containing Streptococcus mutans, Lactobacillus casei and Candida albicans were formed on hydroxyapatite disc. 20 μM, 10 mM and 20 mM erythrosine were applied as a photosensitizer for 3 minutes, and then light-emitting diode (LED) irradiated for 24 seconds. Colony-forming unit (CFU) were measured and biofilms were observed using confocal laser scanning microscopy (CLSM). CFU were significantly decreased in the PDT groups using 10 - 20 mM erythrosine (10 mM, 20mM) and the results were also confirmed by CLSM. This study confirms the high antimicrobial effect of photodynamic therapy using plaque disclosing agent as a photosensitizer.

• Journal of environmental and Sanitary engineering
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• v.23 no.2
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• pp.71-79
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• 2008

We examined 165 unchlorinated natural drinking water samples for the presence of E. coli group resistant to antimicrobial agent and chlorine in nothern Gyeongbuk area in 2007. Among 165 water samples, 21 samples(12.7%) were positive to total coliforms and Six genus, 16 strains of E. coli groups isolated from 16 samples showed resistance against more than one antimicrobial agent such as Ampicillin, Tetracycline and Chloroamphenicol. Among 16 strains, 14 strains resistant to Ampicillin, 9 strains resistant to Tetracycline and one strain resistant to Chloroampenicol. but all 16 strains did not contain any integron gene cassettes, which contribute to the spread of antimicrobial resistance alleles by lateral gene transfer of gene cassettes in a variety of enteric bacteria. The minimal inhibitory concentration(MIC) of 14 strains which showed resistant to Ampicillin was between $12{\mu}g/m{\ell}$ and $32{\mu}g/m{\ell}$, Nine strains resistant to Tetracycline showed between $32{\mu}g/m{\ell}$ and $128{\mu}g/m{\ell}$ and one strain resistant to Chloroampenicol showed $128{\mu}g/m{\ell}$. The chlorine sensitivity of 16 strains isolated from unchlorinated natural water sample did not show any difference among strains by the concentration of initial free chlorine and elapsed time after chlorine treatment. All 16 strains were killed after 1hr. exposure at $0.2mg/m{\ell}$ of free chlorine per liter or 30minutes exposure at $0.4mg/m{\ell}$ of free chlorine per liter.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.352-355
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• 2004

The extracts from 70 different plant natural products were used to investigate the antimicrobial activities against Brachyspira hyodrsenteriae, the causative agent of swine dysentery. Among them, the extracts from Terminalia chehula exhibited the highest antimicrobial activities against B. hyodysenteriae. It showed the antimicrobial activity against B. hyodysensteriae mostly in parts of its shell. Minimum inhibitory concentration (MIC) of the water extracts of T chehula was 12.5 mg/ml. After organic solvent extractions, the ethylacetate extracts exhibited higher antimicrobial activities against B. hyodysenteriae, and their antimicroactivities were similar to that of the tannin. In conclusion, these findings suggest that the extracts from T chebula may be used as animal feed additives for their antimicrobial activities against B. hyodysenteriae.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1009-1013
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• 2019

Polymeric nanoparticles are widely used for drug delivery due to their biodegradability property. Among the wide array of polymers, chitosan has received growing interest among researchers. It was widely used as a vehicle in polymeric nanoparticles for drug targeting. This review explored the current research on the antimicrobial activity of chitosan nanoparticles (ChNP) and the impact on the clinical applications. The antimicrobial activities of ChNP were widely reported against bacteria, fungi, yeasts and algae, in both in vivo and in vitro studies. For pharmaceutical applications, ChNP were used as antimicrobial coating for promoting wound healing, preventing infections and combating the rise of infectious disease. Besides, ChNP also exhibited significant inhibitory activities on foodborne microorganisms, particularly on fruits and vegetables. It is noteworthy that ChNP can be also applied to deliver antimicrobial drugs, which further enhance the efficiency and stability of the antimicrobial agent. The present review addresses the potential antimicrobial applications of ChNP from these few aspects.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.51-68
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• 2001

The result of studying the epidemiological characteristics of Salmonella strains which have been isolated from the domestic animals in Gyeongbuk province from February 1998 to August 2000 were summarized as follows. The isolation rates of Salmonella strains were 2.0% from cattle feces, 6.3% from cattle lymph node, 9.5% from pig feces, and 25.1% from pig lymph node. In poultry, the isolation rates were 30.3%. The isolates of Salmonella showed positive reaction for MUCAP test, methyl red test, but showed negative reaction for urea test, indole test, Voges Proskauer test. On TSI agar, the isolates showed acid butt, alkaline slant. Also, the isolates were identified as Salmonella strain by API 20E kit. Non H$_2$S Production Salmonella strains isolated from poultry were identified as S gallinarum. As a result of serotyping, B group were the most common in cattle and pig, Dl in chickens. 21 serovars were found. the common serovar from the domestic animals was S typhimurium, S derby, S agona, S schwarzenground, S enteritidis and S gallinarum. The most commonly encountered serovars in cattle were S agona and S typhirimurium in pig, S gallinarum in chicken. As a result of antimicrobial susceptibility test, all Salmonella isolates were susceptible to amikacin, ciprofloxacin, norfloxacin; cefotaxime and polumcin B. The resistance rates to tetracycline and streptomycin was 58% and 56%, respectively. 69.3% of all isolates were resistant to more than one antimicrobial agent. Out of the resistant isolates, the isolates resistant to streptomycin and tetracycline was 36%. There were 24 strains of multiresistant isolates resistant to more than 5 antimicrobial agents. S typhimurium were resistant to all antimicrobial agents, also had a lot of multiresistant strains. Therefore, S typhimurium was considered as a major agent of antimicrobial resistance.