• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.261-265
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• 1994

To detect naturally occurring bioactive compounds in unused marine resources such as marine by-products and algae, the screening test for the antimicrobial compounds containing in Asterina pectinifera, Halocynthia rotetzi skin, Nototodarus sloani ink. Anthocidaris crassispina skin, and four algae(Sargassum horneri, Agarum cribrosum, Odonthalia corymbifera and Desmarestia ligulata) was carried out. The minimum inhibitory concentrations(MIC, ${\mu}g/disk$) of ether and methanol fractions extracted from Sargassum horneri against Bacillus subtilis were 80 and 70 ${\mu}g/disk$, respectively. The MICs of the ether, acetone and methanol fractions extracted from Sargassum horneri against Staphylococcus aureus were 160, 180 and 70 ${\mu}g/disk$, respectively. In addition, the MICs of ether and acetone fractions extracted from Odonthalia corymbifera against Staphylococcus aureus were 50 and 170 ${\mu}g/disk$, respectively. These nonpolar fractions showed the strongest antimicrobial effect among several fractions extracted from tested marine resources.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.360-365
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• 1992

Clinical isolates of 8 ofloxacin resistant Staphylococcus auresu (ORSA) were subjected to MIC test, Southern analysis on gyrA locus and nucleotide sequence analysis of 290 bp of gyrA gene (gyrA-290) spanning amino acid 26 to 121 in order to understand the mechanism of quinolone resistance in Staphylococcus aureus. ORSAs showed highlevel resistance against quinolones (8-250 fold increase of MICs) and also significant resistance agianst ${\beta}-lactams$ (2-32 fold increase of MICs). However, ORSs did not show any change in sensitivity agianst vancomycin. Southern analysis of ORSAs with HindIII, PstI and AluI revealed RFLPs on gyrA locus. In order to further analyze the gyrA gene, gyrA-290 was amplified by PCR and cloned to pTZ vector. Subsequent nucleic acid sequence analysis of gyrA-290 demonstrated a point mutation of C to T resulting amino acid change of Ser-84 to Leu-84 in all 8 ORSA strains. The substitution at 84th amino acid of tyrase A might confer one mechanism of high level quinolone resistance in Staphylococcus aureus.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.113-121
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• 2005

Antimicrobial effects of Camellia japonica L. were determined against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes using paper disc method, and minimum inhibitory concentrations (MICs) were measured. Methanol extract (MEex), water fraction (WAfr), and butanol fraction(BUfr) showed antimicrobial effects against all tested microorganisms, with MEex showing strong antimicrobial effect against S. aureus and L. monocytogenes, and WAfr, Bufr, and ethylacetate fraction (EAfr)against S. aureus. No effects were observed in n-hexane fraction (HEfr) and chloroform fraction (CHfr) against all tested microorganisms. All species grown in the medium adding fractions of Camellia Japonica L. leaves extact were inhibited from WAfr and BUfr, repectively.(meaning not clear) MEex showed over 25% inhibitory effect against all tested microorganisms. BUfr showed over 50% inhibitory effect against all microorganisms except L. monocytogenes. EAfr and WAfr showed over 30% effect against S. aureus and L. monocytogenes. MICs of MEex against S. typhimurium and BUfr against S. aureus were 625 g/mL, indicating C. japonica L. extract can exert antimicrobial activity even at low concentration.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.283-294
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• 1987

One hundred and fifty-seven strains of staphylococci isolated from various clinical specimens and 80 of Gram-negative bacilli from urine of patients with urological diseases were tested for resistance to antimicrobial drugs by microdilution broth method. Among staphylococci, 50 to 89% of the strains were resistant to gentamicin(Gm), kanamycin(Km), erythromycin(Em), nalidixic acid(Na), and tetracycline. Ninety per cent MIC was lowest in ciprofloxacin(Cp), followed by vancomycin(Vc), trimethoprim(Tp), enoxacin(Ex), and norfloxacin(Nf) with the values of two ${\mu}g/ml$ or lower. Twenty-seven strains were resistant to methicillin(MR), with 24 strains of Staphylococcus aureus and 3 of S. epidermidis. All strains of MR S. aureus were resistant to oxacillin, rifampin(Rf), Gm, Km, Em, Na, and Tc, and no strain was resistant to Vc and Tp. Almost all staphylococci isolated from urine were S. epidermidis and sensitive to most drugs tested without MR strain. Among Gram-negative bacilli from urine, Escherichia coli(43 strains) was most frequently isolated, and followed by Klebsiella spp.(11), Proteus spp.(10), Serratia spp.(10), and Pseudomonas aeruginosa(6) in the decreasing order. The majority of E. coli and Serratia spp. were resistant to chloramphenicol(Cm), Tc, streptomycin, sulfisomidine(Su), ampicillin(Ap), Km, and carbenicillin(Cb), and 50 and 90% MICs of these drugs were also high. In Klebsiella spp., 54% or more were resistant to Cm, Su, Ap, cephalothin, and Cb. Proteus spp. were susceptible to most drugs tested, but Pseudomonas were resistant to nearly all drugs tested except Rf, amikacin, and moxalactam(Mx). All Gram-negative bacilli tested were found to be susceptible to Mx. New quinolone carboxylic acid compounds, such as Nf, Ex, and Cp showed very high antimicrobial activities against the majority of organisms tested except Pseudomonas, and 50 and 90% MICs of Nf and Ex were always equal or 2 to 4 times higher than Cp. Organisms multiply resistant to drugs were noted in almost all isolates tested. Twenty-seven strains of staphylococci were multiply resistant to 11 or more drugs, and 6 of Klebsiella spp. to 8 to 11 drugs. The most frequent multiplicity of durg resistance were 7 and 8, 12, and 13 in E. coli, Serratia spp., and Pseudomonas, respectively. No strain was resistant to more than 5 drugs in Proteus spp..

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1396-1402
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• 2000

The effects of Coptis chinensis Franch(CCF) extract on the growth, acid production, cell adherence and glucosyltransferase(GTase) activity of Streptococcus mutans JC-2 were investigated. Methanol extract from CCF showed a strong inhibitory effect on the growth of S. mutans. The minimal inhibition concentration(MIC) of the methanol extract was determined as $130\;{\mu}g/mL$, whereas MIC of water extract was $200\;{\mu}g/mL$. MICs of berberine and palmatine were $50\;{\mu}g/mL$ and $110\;{\mu}g/mL$, respectively, showing stronger antimicrobial activities than the extracts of CCF. Antimicrobial activities of methanol extract, berberine and palmatine were not decreased by heating at $121^{\circ}C$ for 15 min, suggesting that the antimicrobial components including berberine and palmatine are heat-stable. Acid production of S. mutans was decreased by methanol and water extracts, berberine and palmatine. The activity of GTase was inhibited by methanol extract, berberine and palmatine at $300\;{\mu}g/mL$ with 23.2%, 46.1% and 17.1%, respectively, but was not inhibited by water extract. The water extract and palmatine at sub-MICs inhibited the adherence of S. mutans to glass surface by 59.2% and 41.7%, respectively. These results suggest that CCF extracts have anticariogenic effects and could be used as an anticariogenic food additive.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.2061-2065
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• 2007

The chemical components of the essential oil from Artemisia feddei LEV et VNT. were analyzed using GC-MS. Ninety-nine compounds, accounting for 96.23% of the extracted essential oil, were identified. The main oil compounds were 1,8-cineole (16.86%), chamazulene (9.04%), ${\alpha}$-terpineol (8.18%), ${\alpha}$-phellandrene (5.78%), ${\alpha}$-thujone (5.51%), ${\alpha}$-terpinyl acetate (5.07%), borneol (5.08%), ${\beta}$-caryophyllene (4.71%), camphor (4.04%), and terpinen-4-ol (3.04%). The antimicrobial activity of the essential oil and some of its compounds was tested against 15 different genera of oral bacteria. The essential oil from A. feddei had a considerable inhibitory effect on all the obligate anaerobic bacteria tested (MICs, 0.025 to 0.05 mg/ml; MBCs, 0.025 to 0.1 mg/ml), whereas the major compounds demonstrated different degrees of growth inhibition.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.671-676
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• 1998

Five hundred and seventy clinical strains of Pseudomonas aeruginosa were isolated from August 1993 to August 1994 in Korea and screened for their resistance to ciprofloxacin, norfloxacin, and ofloxacin. Among these, two P. aeruginosa strains (PA150 and PA300) were selected based on their strong resistance (MICs > 50mcg/ml) to all three quinolones. The susceptible strain as well as two resistant strains had proton gradient-dependent efflux system. Efflux system in PA300 showed different specificities to ofloxacin and ciprofloxacin while PA150 had less permeability for ofloxacin. Ofloxacin had a less inhibitory action on DNA synthesis in permeabilized cells of PA150 and PA300 than 1771M. When quinolone resistance determining region (QRDR) in gyrA was sequenced, PA300 had one missense mutation, Asn 116Tyr, which was newly reported in this work. The results showed that PA150 became ofloxacin resistant by reduced ofloxacin accumulation due to the existence of efflux system and low permeability, while resistance of PA300 was due to the efflux system and a mutation in QRDR of gyrA -the target site of quinolone.

• Mycobiology
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• v.31 no.2
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• pp.95-98
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• 2003

Aantifungal agents were tested against 30 clinical isolates of Cryptococcus neoformans var. neoformans using the NCCLS method(M27-A2). Posaconazole, itraconazole and amphotericin B had lower MIC than the remaining four antifungal agents. The MIC result for posaconazole was over 220-fold lower active than fluconazole. Fluconazole MICs for most isolates fell within the dose-dependant range. The overall MIC ranges and $MIC_{50}s$ were amphotericin B(0.03-0.25; 0.25), fluconazole(0.5-64; 16), itraconazole(0.015-1; 0.125), terbinafine(0.06->2; 1), caspofungin(8-32; 32), voriconazole(0.015-0.5; 0.25), and posaconazole(0.015-0.25; 0.06 ${\mu}g/ml$), respectively. In conclusion, the $MIC_{50}s$ of these drugs did not exhibit any sign of an upward shift with the exception of fluconazole and tendency cross-resistance between the seven drugs was not observed. We conclude that in vitro resistance to antifungal agents has not significantly changed despite the recent wide-spread use of triazoles for long-term treatment of Cryptococcal meningitis.

• Korean Journal of Veterinary Service
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• v.26 no.1
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• pp.57-65
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• 2003

The present study was conducted to examine the outbreak state of bovine dermatophytosis in 14 farms(4 dairy farms, 10 Korean indigenous cattle farms) in Gyeongbuk province from November 2000 to November 2001. The causative agents of dermatophytosis was identified by mycological examination. Antifungal susceptibility test of 26 isolates was performed by agar dilution method, using 5 antifungal drugs. Prevalence of bovine dermatophytosis was found to be 13.5%(90/665) in dairy cattle farms and 14.5%(220/1,520) in Korean indigenous cattle farms. The most common age at which this disease occurred was 2-12 months. This disease usually occurred from winter to spring and the occurrence subsequently decreased in the summer. But 4 Korean indigenous cattle farms with poorly hygienic status were occurred all the year round. The causative agent was identified as Trichophyton verrucosum exclusively in these case. Antifungal susceptibility test of T verrucosum (26 strains) was performed by agar dilution method, using 5 antifungal drugs including tolnaftate, griseofulvin, ketoconazole, amphotericin B and terbinafine. All isolates were highly sensitive to 5 antifungal drugs (geometric mean MICs 0.004∼0.032 $\mu\textrm{g}$/$m\ell$). The isolates were the most sensitive to especially tolnaftate.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.223-232
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• 2002

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) CCARM 3251 and S. aureusKCTC 1928 have been known to be resistant to many kinds of antibiotics. The extract of Glycyrrhizae Radix showed antibacterial activity against MRSA and antibiotics-resistant S. aureus. Methods : We examined the effects of the water-soluble extract and the methanol-soluble extract of Glycyrrhizae Radix on MRSA and antibiotic-resistant S. aureus. The methanolic extract was further fractionated with organic solvents such as hexane, chloroform, and ethyl acetate in that order. Results and Conclusions : The methanol-soluble extract of Glycyrrhizae Radix showed relatively high antibacterial activity against MRSA and antibiotic-resistant S. aureus. However, the water-soluble extract of Glycyrrhizae Radix showed no antibacterial activity against MRSA and antibiotic-resistant S. aureus. Among the fractions tested, the chloroform fraction showed the highest antibacterial activity against MRSA and antibiotic-resistant S. aureus. The methanol-soluble extract of Glycyrrhizae Radix minimal inhibitory concentrations (MICs) against MRSA and antibiotics-resistant S. aureus were $5{\;}mg/m{\ell}$ in both. The methanol-soluble extract of Glycyrrhizae Radix was separated using thin-layer chromatography and detected with UV -detector. Further study should be carried out to identify which effects cell growth inhibition of MRSA and antibiotics-resistant S. aureus.