• Archives of Pharmacal Research
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• v.17 no.6
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• pp.438-442
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• 1994

Antimicrobial activity of GL (the aqueous extract from the carpophores of Ganoderma lucidum ($F_RK_{KARST}$) was tested in vitro aginst Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration (MIC). Among fifteeen species of bacteria tested, the natimicrobial activity of GL was of antimicrobial combinations of GL with four kinds of antibiotics (ampicilin, cefazolin, oxytet-racycline and chloramphenicol), the fractional inhibitory concentraction index (FICI) was determined by checkerboard assy for each stain. The antimicrobial combinations of GL with four antibiotics resulted in additive effect in most instances, synergism in two instances, and antagonism in two instances. Synergism was obversed when GL was combined with cefazolin against Bacillus subtilis and Klebsiella oxytoca.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.742-748
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• 1994

As part of our search for less toxic antimicrobial agents from natural resources, the carpophores of Elfvingia applanata$(P_{ers}.)K_{ARST}.$ was extracted with hot water. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration(MIC). Among fourteen species of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.250 mg/ml. To investigate the effect of antimicrobial combinations of EA with four kinds of antibiotics(ampicillin, cefazolin, oxytetracycline and chloramphenicol), the fractional inhibitory concentration index(FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of EA with four kinds of antibiotics resulted in synergism in four instances, but no antagonism was observed. Four instances of synergism were observed when EA was combined with ampicillin against Micrococcus luteus, with cefazolin against Bacillus subtilis, with cefazolin against Micrococcus luteus and with oxytetracycline against Staphylococcus aureus.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.653-658
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• 1996

As part of our search for less toxic antimicrobial agents from natural resources. rutin was isolated from Sophora japonica and then hydrolyzed to quercetin. Antimicrobial activity of quercetin was tested in vitro against five kinds of gram positive and ten kinds of gram negative bacteria by serial broth dilution method. Among fifteen kinds of bacteria tested, the antimicrobial activity of quercetin was the most potent against Proteus vulgaris showing minimal inhibitory concentration(MIC) of 125 ${\mu}$g/ml. To investigate the effect of antimicrobial combinations of quercetin with four kinds of antibiotics (ampicillin, cefazolin, oxytetracycline and chloramphenicol). the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of quercetin with four kinds of antibiotics resulted in synergism in one instance, additive effect in four instances, but no antagonism was observed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.4
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• pp.390-395
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• 2014

Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria. monocytogenes and Bacillus cereus are pathogenic bacteria that should not be detected in cosmetics and foodstuffs. Therefore, we first investigated the antimicrobial activities of extracts of Scutellariae Radix(SR), Coptidis Rhizoma (CR) and salicylic acid(SA) in these pathogenic microorganisms. Although SA has been known to exhibit anti-inflammation and antimicrobial activity against pathogenic microorganisms, a high concentration of SA may cause serious side effects such as skin redness, skin burning, peeling or tissue damage. Hence, we focused on diminishing side effects followed by treatment of a high concentration of SA and investigated whether the combinations of SA with various concentrations(25-400 mg/mL), SR and CR with a concentration(100 mg/mL) which did not show antimicrobial activity against E. coli and P. aeruginosa exhibited meaningful antimicrobial effect against both strains. In our results, the combinations of SA with the lowest concentration(25 mg/mL), SR(100 mg/mL) and CR(100 mg/mL) exhibited significant antimicrobial activity against E.coli in comparison to SA alone(25 mg/mL) showing no antimicrobial activity. Moreover, the combinations of SA (100 mg/mL), SR and CR showed seven times higher antimicrobial activity against E. coli than SA alone(100 mg/mL) and exhibited a significant antimicrobial activity in comparison to ampicilin (p<0.05). The combinations of SA(100 mg/mL), SR and CR showed two times higher antimicrobial activity against P. aeruginosa than SA alone. Therefore, these results indicated that the combinations of SR, CR and SA with low concentration expressed the synergistic antimicrobial effect against E. coli and P. aeruginosa and showed great potential as an antimicrobial agent.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1322-1326
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• 2013

New antifungal agents are required to compensate for the increase in resistance to standard antifungal agents of Candida albicans, which is an important opportunistic fungal pathogen that causes minor infections in many individuals but very serious infections in those who are immune-compromised. In this study, combinations of theaflavin and epicatechin are investigated as potential antifungal agents and also to establish whether antifungal synergy exists between these two readily accessible and cost-effective polyphenols isolated from black and green tea. The results of disc diffusion assays showed stronger antibacterial activity of theaflavin:epicatechin combinations against C. albicans NCTC 3255 and NCTC 3179, than that of theaflavin alone. Minimum inhibitory concentrations (MICs) of 1,024 ${\mu}g/ml$ with theaflavin and 128-256 ${\mu}g/ml$ with theaflavin:epicatechin combinations were found. The fractional inhibitory concentration indexes were calculated, and the synergy between theaflavin and epicatechin against both isolates of C. albicans was confirmed. Theaflavin:epicatechin combinations show real potential for future use as a treatment for infections caused by C. albicans.

• Biomedical Science Letters
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• v.25 no.3
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• pp.288-292
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• 2019

In vitro antimicrobial activities of hot water extracts of Camellia sinensis (L.) O. Kuntze, for carbapenem-resistant Enterobacteriaceae (CRE) were compared to commonly used conventional antimicrobial agents. CRE was not only resistant to imipenem, meropenem or ertapenem, but also to various antimicrobial agents, such as amikacin (> $128{\mu}g/mL$). The hot water extracts of Camellia sinensis (L.) O. Kuntze had the lowest MIC ($0.06{\sim}0.5{\mu}L/mL$) of the carbapenem-resistant E. coli, K. pneumoniae, and Enterobacter spp. tested, and it was possible more potent than various conventional antimicrobial agents. Synergistic combinations of the extract with used commonly antimicrobial agents might even improve its antimicrobial chemotherapy property.

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.153-160
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• 1995

As part of our search for less toxic antimicrobial agents from natural resources, the antimicrobial activity of Elfvingia applanata $(P_{ers.})\;K_{arst.}$ extract was examined alone and in combination with naringenin. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against nineteen strains of bacteria and eleven strains of fungi by serial broth dilution method, and expressed by minimal inhibitory concentration (MIC). Among nineteen strains of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.125 mg/ml. EA also inhibited the growth of the selected fungi at higher concentrations ranging from 7.5 mg/ml to 15.0 mg/ml. To investigate the effect of antimicrobial combinations of EA with naringenin, the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of EA with naringenin resulted in partial synergism against Staphylococcus aureus only, and showed additive effect in two strains including Klebsiella pneumoniae and Salmonella typhi. Antagonism was not found.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.625-631
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• 2002

The effect of combinations of 8 antimicrobial agents on the growth of Streptococcus mutans and Streptococcus sobrinus was investigated with the minimum inhibitory concentration and fractional inhibitory concentration(FIC) and ${\Sigma}FIC$ index. According to the ${\Sigma}FIC$ values by. The American Society for Microbiology and Berenbaum, Approximately 34% and 82% of the combinations were synergistic respectively. Partial synergy described by Isenberg was also observed in the half of the combinations. There was a tendency for additive antimicrobial effect against cariogenic bacteria though the test results showed difference according to the applied values. It may be beneficial to use combined antimicrobial agents that have various activities against an ecosystem and metabolism of bacteria than using individual agents.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.407-411
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• 1992

As part of our search for less toxic antimicrobial substances from natural resources, naringin was isolated from feels of Citri fructus and then hydrolyzed to naringenin. The antimicrobial activity of naringenin was examined by measuring the minimal inhibitory concentration(MIC) against fourteen species of bacteria. The antimicrobial activity of narngenin in combination with rutin or hesperetin was evaluated by checkerboard method. Among fourteen species tested, the antimicrobial activity of naringenin was the most prominant against Staphylococcus aureus and Shigella boydii showing MIC of $100\;{\mu}g/ml$ for both species. Combinations of naringenin with rutin or hesperetin showed synergism against several species of bacteria, but no antagonism was observed.

• Particle and aerosol research
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• v.12 no.3
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• pp.73-80
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• 2016

Bioaerosol inactivation becomes important as people recognize the significance on the health effects of bioaerosols. There are several ways to inactivate such bioaerosols such as antimicrobial filters, UV, etc. For the on-filter-inactivation, proper antimicrobial materials coating should be applied. Recently, air ions are adopted to effectively reduce germ and virus activity. Limitations arise when each method is applied separately. Coating materials can experience chemical instability over time and temperature. Ionizers can generate ozone to prepare high ion concentrations. Combinations of developed techniques to enhance the inactivation efficiency were suggested. Researches on the air sterilization are reviewed and outlook is highlighted. Proper techniques such as combinations of filter material coating and air ion generation can be used to make air quality better for human living.