• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.631-640
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• 2012

Objectives : This study mean to confirm the antibacterial activity of a garlic extract widely culturing in our region and was to determine the effect of dentifrice containing 0.1% extracts of garlic on dental plaque and gingivitis in a double blind and clinical studies in 50 healthy adults aged from 20 to 22 years who provided a consent for their participation. Methods : The antibacterial activity was evaluated using triple distilled water and the Kirby-Bauer disk diffusion method and the minimal inhibitory concentration(MIC) against various pathogens for periodontal disease, such as P. gingivalis 381(ATCC33277), was estimated. The experimental groups classified according to the concentration of garlic extract used: 10,000ppm(A), 5,000ppm(B), 2,500ppm(C), 1,000ppm(D). Oral examination of subjects was performed through clinical periods and on day of baseline, 6, 12, 19, 25 days plaque index and gingival index were scored by Turesky' modified index and Loe & Silness index. After 12, 19, 25 days use of their respective dentifrices, statistically decreases of plaque index, gingival index were shown in both the experimental and the control group, respectively. Results : There was significant antibacterial activity in the "2,500ppm(C)" group against P. gingivalis 381. Experimental group exhibited significantly the lower plaque levels and the higher levels of gingival health by the use of the dentifrices contained extract of garlic from 6 days compare with control group(p<0.05). The degree of decrease was more significant on gingivitis level of the experimental group than the control group(p<0.05). Conclusions : This findings indicated that the oral products containing a garlic extract is effective in preventing and treating periodontal diseases, and has potential value in inhibiting periopathogens.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.328-333
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• 1999

Susceptibility of 61 strains of Helicobacter pylori to metronidazole was examined by both the disk diffusion method using a cut-off of 15㎜ for resistance and the E test with a cut-off of 8㎎/l. The MIC/sub 50/ and MIC/sub 90/ by the E test were 2 ㎎/l and 256㎎/l, respectively. Metronidazole resistance was found in 22 (36％) out of the 61 H. pylori strains by the E test and in three additional strains by the disk diffusion method. Amongst the latter three isolates, the MICs by the E test were 4 ㎎/l, 6㎎/l, and 6㎎/l, respectively. These figures are one log₂ or half log₂ dilution lower than the cut-off of 8㎎/l recommended as resistance for the E test. All 22 metronidazole resistant H. pylori isolates by the E test that were subjected to random amplified polymorphic DNA (RAPD) fingerprinting showed different DNA fingerprints. Interestingly, >90％ of resistant isolates possess two common DNA bands of 0.4 and 0.9 kb. This study demonstrates that the results of the disk diffusion method for testing H. pylori susceptibility to metronidazole correlates well with that of the E test. The criteria for interpretation need to be internationally standardized so that the results from different centers can be compared.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.343-352
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• 1999

Vancomycin resistant enterococci (VRE) have emerged as an important nosocomial pathogen. Since 1989 the Center for Disease Control, United States, has reported a rapid increase in the incidence of enterococcal bacteremia and endocarditis infection by VRE. It was suggested that the use of avoparcin was associated with the appearance of VRE in animal husbandry. To date, several detection methods have been used based on conventional methods of culture and gene detection. However, these methods have some limitations such as time-consuming, laborious and additional differential needs. Therefore, In this study a multiplex PCR method was established to detect and differentiate resistance types of enterococci which specifically amplify the four van genes encoding vancomycin resistance elements. Using the method, we investigated the incidence rates and types of VRE from farms using or not using avoparcin. A total of 1091 animal fecal samples were collected from 70 pig and 32 poultry farms. A total of 425 of enterococci were isolated from samples. Of the 425 isolates, 11 of the them showed a pattern of high-level vancomycin resistance (MIC : $64{\sim}256{\mu}g/ml$) which was associated with the presence of the vanA or vanB gene. Fifty-seven isolates showed a pattern of low-level vancomycin resistance (MIC : $3{\sim}8{\mu}g/ml$) associated with the vanC-1 or vanC-2 gene. Interestingly, all isolates with high-level vancomycin resistance were from farms that have never used avoparcin. Moreover, the high-level VRE isolation rate in Korea (2.58%) was much lower than that of other countries (50% in England, 7% in Belgium) where avoparcin have been used. In conclusion, the multiplex PCR method established in this study could be applied for detection of VRE.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.465-474
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• 2014

This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an $IC_{50}$ value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ${\geq}2.5 $ MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HD-Cinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.299-306
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• 2016

Purpose: Curcuma aromatica Salisb., commonly known as turmeric, has long been used as a powerful health-promoting anti-inflammatory or antioxidant that supports cellular health of the human body. The objective of this study was to compare the antioxidant and antimicrobial activities of the samples with or without fermentation. Methods: Antioxidant activities of the samples were compared using total phenol, flavonoid contents, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Antimicrobial activities were also examined using the paper disc method and minimum inhibitory concentration (MIC). Results: Organic acid content of the C. aromatica Salisb. fermented with Aspergillus oryzae (FCAS) showed a significantly higher value of 0.41% than that of the typical sample without fermentation (CAS) which showed a value of 0.27% (p<0.001). Total phenol and flavonoid contents of the CAS and FCAS did not show significant differences. However, ABTS cation radical scavenging activity and DPPH radical scavenging activity were significantly increased in the samples with fermentation (p<0.001, p<0.01), respectively. The samples of the disc showed inhibited growth of gram positive Bacillus cereus (FCAS 3.70 cm and CAS 2.73 cm) and Staphylococcus aureus (FCAS 2.70 cm and CAS 1.97 cm). MIC of the FCAS (0.25-0.50, 0.5-1.00 mg/mL) was higher than that of the CAS (1.00-2.00, 2.00-3.00 mg/mL), respectively. Conclusion: C. aromatica Salisb. with fermentation showed higher antioxidant and antimicrobial activities in this study. Thus we conclude that fermentation can be a helpful process for more effective application of C. aromatica Salisb. with fermentation in the health-promoting food industry.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.3
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• pp.159-172
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• 2015

Treatment of polymicrobial infected musculoskeletal defects continues to be a challenge in orthopaedics. This research investigated single and dual-delivery of two antibiotics, vancomycin and amikacin, targeting different classes of microorganism from a biodegradable calcium sulfate-chitosan-nHA microsphere composite scaffold. The addition of chitosan-nHA was included to provide additional structure for cellular attachment and as a secondary drug-loading device. All scaffolds exhibited an initial burst of antibiotics, but groups containing chitosan reduced the burst for amikacin at 1hr by 50%, and vancomycin by 14-25% over the first 2 days. Extended elution was present in groups containing chitosan; amikacin was above MIC ($2-4{\mu}g/mL$, Pseudomonas aeruginosa) for 7-42 days and vancomycin was above MIC ($0.5-1{\mu}g/mL$ Staphylococcus aureus) for 42 days. The antibiotic activity of the eluates was tested against S. aureus and P. aeruginosa. The elution from the dual-loaded scaffold was most effective against S. aureus (bacteriostatic 34 days and bactericidal 27 days), compared to vancomycin-loaded scaffolds (bacteriostatic and bactericidal 14 days). The dual- and amikacin-loaded scaffolds were effective against P. aeruginosa, but eluates exhibited very short antibacterial properties; only 24 hours bacteriostatic and 1-5 hours bactericidal activity. For all groups, vancomycin recovery was near 100% whereas the amikacin recovery was 41%. In conclusion, in the presence of chitosan-nHA microspheres, the dual-antibiotic loaded scaffold was able to sustain an extended vancomycin elution longer than individually loaded scaffolds. The composite scaffold shows promise as a dual-drug delivery system for infected orthopaedic wounds and overcomes some deficits of other dual-delivery systems by extending the antibiotic release.

• Fisheries and Aquatic Sciences
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• v.22 no.6
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• pp.13.1-13.9
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• 2019

Background: Marine invertebrates are well known as pivotal bioresources with bioactive substances such as anti-inflammatory sterols, antitumor terpenes, and antimicrobial peptides. However, there are few scientific reports on chemical compositions and bioactivities of marine invertebrates from the East Sea of South Korea. Methods: In this study, chemical compositions and biological activities were evaluated on both 70% EtOH and hot water extracts of 5 species of marine invertebrates (Crossaster papposus japonicus, Actinostola carlgreni, Stomphia coccinea, Actinostola sp., and Heliometra glacialis) collected from the East Sea of South Korea. The antioxidant activities were measured by ABTS radical scavenging assay. The cytotoxicity and anti-inflammatory activity were evaluated using MTT and Griess reagents. Moreover, the antibacterial effect was evaluated using paper disc assay and minimum inhibitory concentration (MIC) assay. Results: In the results of antioxidant activities, 70% EtOH extract of A. carlgreni showed the highest activity ($IC_{50}\;0.19{\pm}0.03mg/ml$) compared to other extracts. Moreover, 70% EtOH extract of A. carlgreni could significantly suppress the nitric oxide (NO) production in lipopolysaccharide-induced RAW 264.7. All extracts treated under $400{\mu}g/ml$ have no cytotoxic effects on RAW 264.7 macrophages. In the antibacterial test, both 70% EtOH extracts of C. papposus japonicus and H. glacialis showed a significant antibacterial effect on Staphylococcus aureus. The MIC values were evaluated at 256 and $512{\mu}g/ml$, respectively. Conclusions: These results suggested the bioactive potentials of marine invertebrates from the East Sea of South Korea in pharmaceutical and nutraceutical applications.

• Korean Journal of Pharmacognosy
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• v.50 no.3
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• pp.191-197
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• 2019

Sepsis, an infectious disease, is a life-threatening condition that arises when the response to infection causes injury to tissues and organs. The purpose of this study was to demonstrate whether ABHC-1 and ABHC-2, two functional extracts from herbal complex, have an anti-bacterial effect against Escherchia coli in vivo, in vitro experimental model. ABHC-1 and ABHC-2 showed the antibacterial activity against the bacteria by paper disc method. The minimum inhibitory concentration (MIC) was measured using alamar blue reagent. The MIC was shown at $60{\mu}g/ml$ from ABHC-1 and $500{\mu}g/ml$ from ABHC-2 against E. coli. We next examined the effect of ABHCs on the production of inflammatory cytokine, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), which is related to the induction of inflammation, in RAW 264.7 cell. ABHC-1 and ABHC-2 increased $TNF-{\alpha}$ production of RAW 264.7 cell in a dose-dependent manner while two extract decreased $TNF-{\alpha}$ production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell in a dose-dependent manner. At a dose of $1{\times}10^8$ E. coli. i.p., non-treated mice were succumbed, while most of mice treated with ABHC-1 were survived. Therefore, our results suggest that ABHC-1 has anti-bacterial activity and can be a novel therapeutic agent against infectious diseases.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.61-74
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• 2023

The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 ㎍/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC₅₀ values of 47.15 ± 13.10 and 122.69 ± 9.12 ㎍/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.93-100
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• 2005

This research was performed to investigate the possibilities of industrial usage of camellia (Camellia japonica L.) by examining the antioxidant and antimicrobial effects of methanol extract with different sections. Content of total phenolics, DPPH radical scavenging activities and antibacterial activity of young leaf, mature leaf, flower bud, flower, bark, and seed of camellia were compared in vitro experimental models. Total phenolics was contained the higher in young leaf (74.62 mg), flower bud (65.02 mg) and flower (62.42 mg) but less than 20.95 mg per 100 g of dry weight in other parts of Camellia japonica L. And effects of antioxidant measured by DPPH radical scavenger activity ($RC_{50}$, reduce concentration 50%), was shown higher $7.16{\sim}18.14\;{\mu}g/m{\ell}$ in methanol extract of young leaf, flower bud and flower than $61.23\;{\mu}g/m{\ell}$ of BHT as a chemical oxidant. Also, the antimicrobial activity of Camellia japonica L. extracts determined using a paper disc method against food-borne pathogen and food spoilage bacteria, the young leaves extracts showed the most active antimicrobial activity against 7 kinds of harmful microorganisms. Flower bud extracts showed the highest antibacterial activity against P. aeruginosa and Enterobacter spp. C1036. In addition, the minimum inhibitory concentration (MIC) of young leaf extract against B. subtillis,S. fradiae,S. aureus,E. coli,P. aeruginosa, Enterobacter spp. C1036, and S. typhimurium were revealed 1 to 15 ${\mu}g/m{\ell}$. As a result, antimicrobial activity of camellia extracts was shown higher gram positive bacteria than gram negative bacteria.