• Korean Journal of Microbiology
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• v.42 no.3
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• pp.165-171
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• 2006

ERM proteins transfer the methyl group to $A_{2058}$ in 23S rRNA to confer the resistance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism ranging from antibiotic producers to pathogens. To define the functional role of peptide segment encompassing amino acid residues 1 to 25 in NTER (N-terminal end region) of ErmSF, one of the ERM proteins, DNA fragment encoding mutant protein deprived of that peptide was cloned and overexpressed in E. coli to obtain a purified soluble form protein to the apparent homogeneity in the yield of 12.65 mg per liter of culture. The in vitro activity of mutant protein was found to be 85% compared to wild type ErmSF, suggesting that this peptide interact with substrate to affect the enzyme activity. This diminished activity of mutant protein caused the delayed expression of antibiotic resistance in vivo, that at fIrst cells expressing mutant protein showed the retarded growth due to the antibiotic action but with time cells inhibited by antibiotic gradually recovered the viability to exert the resistance to the same extent as those with wild type protein.

• Natural Product Sciences
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• v.14 no.2
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• pp.138-142
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• 2008

The composition of essential oils from Chrysanthemum zawadskii var. latilobum and C. indicum were analyzed and compared. The results of gas chromatography-mass spectrometry revealed there were distinctly different compositional patterns between C. zawadskii var. latilobum and C. indicum essential oils. The combinatorial effect of the oil of C. zawadskii var. latilobum and C. indicum, with various antibiotics was assessed against antibiotic-susceptible and -resistant strains of Staphylococcus aureus and Streptococcus pneumoniae. The essential oil fraction significantly inhibited most of the tested antibiotic-susceptible and -resistant strains of S. pneumoniae, with minimum inhibiting concentrations (MICs) ranging from 0.5 to 4.0 mg/ml. The fractional inhibiting concentration indices (FICIs) of the oils when combined with antibiotics against S. aureus and S. pneumoniae ranged from 0.26 to 0.75, and showed synergistic or additive effects.

• Natural Product Sciences
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• v.17 no.4
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• pp.296-302
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• 2011

We determined the inhibitory activity of the essential oil fraction obtained by steam distillation from the fresh and dried leaves of Perilla frutescens var. acuta against some pathogenic Salmonella and Vibrio spp. The activities of compounds isolated from the essential oils, apiol and myristicin, were also tested and the results were compared with those of the essential oil fraction. The Perilla essential oil fraction and its main components showed significant inhibition against antibiotic-susceptive and antibiotic-resistant strains of the tested Salmonella and Vibrio strains. Synergistic or additive effects were identified by combing the oils with ampicillin by checkerboard-titer tests. We conclude that essential oils from P. frutescens can be useful in the treatment of Salmonella and Vibrio infections and as safe additives to food materials for the prevention of contamination of food by these bacteria. This is especially important because of the rapid increase in antibiotic-resistant strains, which could cause severe symptoms in humans.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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• pp.103-108
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• 1995

Antibiotic and physico-chemical properties of an active compound from actinomycetes isolate G-37, of which the culture filtrate had an inhibitory effect against tobacco mosaic virus(W) infection, were examined. The active compound, which was purified by ethylacetate extraction, silica gel column chromatography, preparative thin layer chromatography, and high performance liquid chromatography, showed strong antibacterial activities especially against Gram-positive bacteria including Bacillus subtillis, Sarcina lutea and Staphylococcus aureus. From the IH-NMR, FAB/RfS, UV spectral data, and physicochemical properties, the active compound of G-37 appears to belong to a peptide antibiotic group. Among the known peptide antibiotics in the antibiotic group, No. 280, A-30912, and Taitomycin showed molecular weights and ultra violet spectrum similar to those of the active compound from G-37, but was not identical to the compound, which suggests that it may be a new peptide antibiotics.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.293-295
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• 2003

Total 70 isolates of Escherichia coli obtained from pigs were studied. Forty four isolates had $\textregistered$-hemolytic activity which was heat labile. Minimum inhibitory concentration test indicated that 40 isolates (57.1%), 15 isolates (21.4%), 23 isolates (32.9%), and 5 isolates (7.1%) were resistant to ampicillin, cephalothin, gentamicin, and norfloxacin, respectively. None of them were extended spectrum $\textregistered$-lactamases (ESBLs) producer when the double disk synergy test (DDST) was performed.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.191-202
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• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.89-97
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• 1985

To find antibacterial strains of the soil microorganisms in Korea, they were isolated from the soil samples of different locations and screened for antibacterial activity against several standard microorganisms. An isolate among them had antibacterial activities against gram-positive and gram-negative bacteria. The examination of its morphological, biochemical, cultural and physiological characteristics according to the International Streptomyces Project methods showed that it belongs to the genus Streptomyces. This strain appears to be a novel strain when it was compared with those species of the genus which have been so far reported. The antibiotic metabolite was produced in the submerged culture of the strain. This metabolite was extracted from the culture filtrate and purified by ion-exchange column chromatography. Physico-chemical properties of the antibacterial metabolite were characterized.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.1
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• pp.103-111
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• 2021

The purpose of this study is to investigate the antibacterial efficacy of cotton and silk/rayon fabrics dyed with Saururus chinensis extract against antibiotic-resistant strains. The concentration of the concentrated dye in the Saururus chinensis extracts was 1.1% (o.w.f), and the liquor ratio was 1:10 at 30-70℃. The mordanting method was a post mordanting method. The concentration of Al2(SO4)3, CuSO4 5H2O and FeSO4 and7H2O mordant was 5% (o.w.f), and the liquor ratio was 1:40. In order to assess the antimicrobial activity of naturally dyed fabrics, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, was used by incubating it in Brain Heart Infusion Agar (BHA) including Oxacillin (2㎍/ml) and Fungizone (2.5㎍/ml) and Brain Heart Infusion broth (BHI; Detroit, MI, USA.) The investigation of the reduction of the rate of antibiotic-resistant strains to dyed cotton fabrics and silk/rayon fabrics revealed that Cu mordanting fabric has the highest antimicrobial effects, with the rate of 99.7%, and Fe mordanting fabric has the lowest, with 77.7%. Non-mordant cotton fabrics also show a high reduction rate of strains (94.6%). In the case of dyed silk/rayon fabrics, it indicates a high reduction in the rate of strains in all fabrics with non-mordant treatment (94.2%), Al mordanting (99.6%), and Cu and Fe mordanting(99.9%).

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.265-269
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• 1996

An isolate of Streptomyces rochei synonym was found to produce antibiotics with narrow anti-microbial spectrum against Streptococcus and Xanthomonas sp. Among the antibiotic complex produced by the strain, the main active compound was isolated, and its physico-chemical properties and biological activities were investigated. Molecular weight of the compound was determined to be ${[M+H]}^+$ 797 (FAB-MS). UV, $^1H \;and\;^{13}C$ NMR, and IR spectra suggested that the compound is a kirromycin-like aurodox group antibiotic. However, the anti-microbial spectrum of the main compound was slightly different from that of kirromycin. In addition, it was newly found that kirromycin showed a selective anti-microbial activity against Streptococcus pyogenes and phytopathogenic Xanthomonas sp.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.258-263
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• 1998

This is the first systematically research which investigates structure-activity relationships(SAR) of antibiotics of polyyne. In this paper, it is reported that tetrayne compounds composed of hydrophilic unit and tetrayne unit has possibility of strong antimicrobial activity. Based on the above results, the possibility of development as an antibiotic medicine was examined to synthesise the more improved antibiotic compounds with synthesized polyhydroxy novel sugar analog possessing the part of tetrayneol moiety.