• 한국미생물·생명공학회지
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• 제32권3호
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• pp.282-285
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• 2004

The polyene antibiotics including nystatin, pimaricin, amphotericin and candicidin are a family of most promising antifungal polyketide compounds, typically produced by rare actinomycetes species. The biosynthetic gene clusters for these polyenes have been previously investigated, revealing the presence of highly homologous biosynthetic genes among polyene-producers such as polyketide synthase (PKS) and cytochrome P450 hydroxylase (CYP) genes. Based on amino acid sequence alignment among actinomycetes CYP genes, the highly-conserved regions specific for only polyene CYP genes were identified and chosen for degenerate PCR primers, followed by the PCR-screening with various actinomycetes genomic DNAs. Among tested several polyene non-producing actinomycetes strains, Pseudonorcardia autotrophica strain was selected based on the presence of PCR product with polyene-specific CYP gene primers, and then confirmed to contain a cryptic novel polyene hydroxylase gene in the chromosome. These results suggest that the polyene-specific hydroxylase gene PCR should be an efficient way of screening and isolating potentially-valuable cryptic polyene antibiotic biosynthetic genes from various microorganisms including rare actinomycetes.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.278-284
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• 1994

Streptomyces spp. purchased from American Type Culture Collection and Institute for Fermentation in Osaka, and donated from Northem Regional Research Laboratory, and those isolated from soil samples were assayed to isolate many plasmids harboring streptomycetes. Among these qrganisms, 5 small size-plasmid carrying organisms SNUS 8810-597A, 8810-600, 8810-754, 8811-344, and 8811-347 were characterized and their plasmids pSJ597, pSJ600, pSJ754, pSJ344, and pSJ347 were isolated in a large scale. The plasmid harboring organisms were sensitive to neomycin, kanamycin, gentamicin, and thiostreptone, but some of them showed weak or strong resistance against streptomycin, chloramphenicol, ampicillin, and tetracycline. It was confirmed that pSJ597 and pSJ600 do not carry antibiotic biosynthetic genes. pSJ600 showed a pock-forming character.

• 대한미생물학회지
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• 제22권1호
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• pp.79-93
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• 1987

The result of various researches mainly in search of 194 Shigella strains, isolated by the Health Research Centers(situated in Seoul city, Inchon city, Pusan city, Kyonggi-Do, Kangwon-Do, Chungchongnam and Buk-Do, Kyongsangnam and Buk-Do, Jollanam and Buk-Do, and Jaeju-Do) in addition to those clinical laboratories of all the general hospitals situated down twon Seoul, conducted during the month of Jan. through Dec. 85, through the reisolating-activity program following its transportation into the laboratory, particularly for a complete check on its correctiveness, are as follows: 1. Isolation processes were performed with the 194 strains obtained from each placeduring the period of investigation: 164 Strains(84.5%) of Sh. flexneri, B group; 6 Strains(3.1%) of Sh. boydii, C group; 24 Strains(12.3%) of Sh. sonnei, D group, which means there's quite a lot in B group while Sh. dysenteriae, A group was not isolated at all. 2. The isolation rate of the 164, B group for subserotype was 1b, 84(51.2%) the highest one, 2(1.2%) on 3a the lowest one, 4, on C group; In D group subserotype II showed 14(58.4%) more than subserotype I. 3. The biological data on sexuality regarding the isolation-strain showed traditional particularity. But the subserotype 1b in B group 2(2.4%) showed gas-growth from glucose. In subserotype 1a, the indole-growth was 88.9% on masculine which was considerably a good one. In the test of arginine dihydrolase subserotype I among D group showed 100% masculine rate. The subserotype 6 among B group showed 92.5% masculine. In the dissolution test of manitol, all subserotypes showed 100% maculine except subserotype 1b. In the dissolutioning test of rhamnose, the subserotype I among D group showed 100% masculine which is the unusual one. 4. Interms of the area among 13 districts examined, Kangwon-Do had 41(21.1%) which is the highest one on its ratio. 5. In terms of season on the strain isolation category, 44(22.7%) is the number isolated in April which is the highest one. 6. In terms of ages, the strain isolation ratio was notably high above the ages of 60 which was 34(17.5%). Next one was 29(14.9%) which was under the ages of 4. 7. In terms of sex, female was 113 or 58.2% while male was 74 or 38.2%, which means the female had more than the male. 8. The result of the resisting capability on the usage of 12 antibiotic medication was; 100% on chloramphenicol; 94.3% on tetracycline, 82.0% on streptomycin, 76.3% on carbenicillin, 74.7% on ampicillin, in regular order. The strain source bearing multimedication resisivity against the 5 antibiotic medication is as many as 117 or 60.3%. Of which 43.3% of 1b sub serotype, B group was the best one, and thus the resistivity against the antistrain medication seems the tendency is being changed. The summing up of the above result shows the total specific strains isolated in each branch in Korea is 194, of which the main type is Sh. flexneri 84.5%. The isolating rate is almost evenly spreading, although the Kangwon-Do showed the highest rate on the above data. It also shows female is higher than male on its statistics. The tendency on age category showed both on old and infancy generations high. However, the resistant capability against antibacteria medication or vaccine was still remaining on habitual one, particularly tending towards multimedication or vaccine trend.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10933-10935
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• 2015

Background: Many scientists have reported Candida species to be of great concern because of the high frequency that they colonize and infect human hosts, particularly cancer patients. Moreover, in the last decades Candida species have developed resistance to many antifungal agents. Based on this, we aimed to identify and determine the prevalence of Candida spp from blood culture bottles among cancer patients and their antifungal resistance pattern. Materials and Methods: From the blood culture bottles isolation and identification of the Candida spp were performed by conventional microbiological techniques. The in vitro antibiotic resistance pattern of the isolates was determined by CLSI guidelines. Genomic DNA was isolated and amplified. Each gene was separated by agar gel electrophoresis. Results: Identification of Candida spp was based on the presence of yeast cells in direct examination, culture and DNA extraction. Of the 68 blood samples collected during the study period (April 2013 to October 2013), five (7.35%) were positive for the presence of Candida spp, 2 (40%) of which were identified as Candida albicans and 3 (60%) were Candida non-albicans. Conclusions: High resistance to amphotricin B was observed among all the Candida non-albicans isolates. Regular investigations into antifungal resistance will help us to get an updated knowledge about their antibiotic resistance pattern which may help the physician in selecting the antibiotics for empirical therapy.

• 대한수의학회지
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• 제27권2호
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• pp.235-243
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• 1987

This paper deals with the distribution of Yersinia spp. isolated from the feces or the cecal contents of 1,755 pigs, 558 cows, 428 pigs slaughtered, 271 dogs slaughtered and 91 deer during the period of March 1985 to February 1986. Isolated Yersinia spp. were examined for serotype, biotype and antibiotic susceptibility of Y. enterocolitica. The results were as follows; One hundred and fourty-three stains of Yersinia spp. were isolated from 141(4.5%) out of 3,103 animals examined and their isolates were identified as Y. enterocolitica(138 strains), Y. kristensenii (3 strains), Y. intermedia(1 strain) and Y. pseudotuberculosis(1 strain). Yersinia spp. were isolated from 122(7.0%) of 1,755 pigs in piggeries, 15(3.5%) of 428 pigs slaughtered and 4(1.5%) of 271 dogs slaughtered, but no Yersinia spp. were isolated from cows and deer. The isolation rate of Yersinia spp. in pigs ranged from 5.9~8.0% in piggeries, it was higher in summer and autumn and highest in fattening pigs groups(10.4%), especially. One hundred and thirty-eight Y. enterocolitica isolates belonged to serotype 0 : 3(95 strains), 0 : 8(13 strains), 0 : 5(7 strains), 0 : 9(6 strains), 0 : 1, 2(1 strain) and untypable(16 strains), among them strains of serotype 0 : 3 biotype 3B(91 strains) were predominant. Antibiotic susceptibility test of 138 isolates of Yersinia spp. was performed by the agar dilution method, using 8 antibiotics as follows: ampicillin(Am), chloramphenicol, kanamycin, nalidixic acid(Na), rifampicin(Rf), streptomycin, sulfadimethoxine(Su) and tetracycline. All the strains tested were susceptible to Rf and Na, but resistant to Su, and 136 strains(98.6%) were also resistant to Am.

• Mycobiology
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• 제40권1호
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• pp.59-65
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• 2012

Antagonistic microorganisms against $Rhizoctonia$ $solani$ were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by $R.$ $solani$ AG2-2(IV) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as $Bacillus$ $subtilis$ subsp. $subtilis$. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance ($^1H$ NMR), carbon nuclear magneric resonance ($^{13}C$ NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.

• 대한한방내과학회지
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• 제34권3호
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• pp.278-288
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• 2013

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) has a cephalosporin and beta-lactam antibiotic-resistant strains. MRSA is one of the major pathogens causing hospital infection and the isolation ratio of MRSA has gradually increased. Consequently, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. Methods : The antibacterial activities of Ipyo-san were evaluated against 2 strains of MRSA and 1 standard Methicillin-susceptible staphylococcus aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MIC) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay performed under dark. Results : The MIC of Ipyo-san water extract against S. aureus strains ranged from 1000 to $2,000{\mu}g/ml$, so we confirmed that it had a strong antibacterial effect. Also, the combinations of Ipyo-san water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Ipyo-san water extract against MRSA has antibacterial activity so it has potential as alternatives to antibiotic agents. For the combination test, we used Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of Ipyo-san water extract was affected by the cell membrane. Conclusions : We suggest that the Ipyo-san water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• 한국약용작물학회지
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• 제25권2호
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• pp.108-114
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• 2017

Background: The study was conducted to investigate the distributions of faecal bacteria in commercial oriental medicine herb products. Methods and Results: A survey was conducted on the microbial contamination levels and antimicrobial specificity of Bacillus cereus and other microbes using 106 oriental medicine herb products on sale in Seoul. Pouring and isolation methods such as standard plate counts were used to identify the bacteria. The isolated bacterias included coliforms, Bacillus spp., Enterococcus spp., Staphylococcus spp., Listeria spp.were identified by using gram staining and an API (analytical profile index) kit. Antimicrobial drugs discs were determined by CLSI (clinical and laboratory standards institute). Conclusions: The bacterial isolates present in the herbal medicines included 98 coliforms, 45 Bacillus spp., 29 Enterococcus spp., and 2 Listeria spp. Among these, there were nine Bacillus cereus strains, one Enterococcus faecium strain, and one Enterococcus faecalis strain present. The 9 Bacillus cereus strains were tested for susceptibility to 36 types of antibiotics products by the disc diffusion method. The strains showed resistance to 13 of these antibiotic products and semi-resistance to 5 antibiotic products. On the basis of these results, any oriental medicine herb product can be assumed to be contain resistant or semi-resistant bacterial strains. Therefore, we suggest prescribing guidelines and special management for the use of antibiotics in farms producing oriental medicine herb products.

• 대한치과기공학회지
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• 제22권1호
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• pp.145-152
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• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

• 대한수의학회지
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• 제56권2호
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• pp.125-127
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• 2016

Gradual mortality of look down fish (Selene vomer) was observed in a private aquarium in Seoul, showing abnormal swimming behavior and lethargy. A bacterial pathogen from kidney was cultured, identified, and confirmed as Vibrio harveyi using Vitek System 2 and 16S rRNA gene sequencing. A predominant bacterial strain, SNUVh-LW2 was proved to be most closely related to isolates from China by phylogenetic analysis with minimum evolution method. Also, tetracycline was considered as the most sensitive antibiotic agent via antibiotic susceptibility test. The group of fish was treated according to the diagnostic result and no more mortality was observed.