• 한국환경보건학회지
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• 제40권3호
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• pp.225-233
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• 2014

Objective: This study was performed in order to investigate the distribution of antibiotic resistant E. coli and water quality in waterscape facilities. Methods: Nine waterscape facilities were selected and classified into three types: ground, wall and general fountain. The items analyzed in this study were pH, turbidity, $KMnO_4$ consumption, total colony, total coliforms, fecal coliforms and E. coli. Additionally, an antibiotic resistance test on E. coli was performed. Results: There were no sampling sites that exceeded the permitted limits of water quality, but the concentration of pollutants was high at the beginning operation in June. Moreover, concentration of turbidity, $KMnO_4$ consumption and total colony were higher in ground fountains than in wall and general fountains. Five species of antibiotic resistant E. coli were detected from three sampling sites. Conclusions: The waterscape facilities were significantly contaminated with water microorganisms, especially total colony, total coliforms and fecal coliforms. Disinfection and filtration systems to remove pollutants should be installed for safe waterscape facilities.

• 대한수의학회지
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• 제49권3호
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• pp.195-200
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• 2009

Avian pathogenic Escherichia coli (APEC) is an important bacterial pathogen of chickens and causes colibacillosis such as airsacculitis, perihepatitis, omphalitis, peritonitis, salpingitis, and pericarditis. As the transfer of antibiotic resistance from animal to humans can be possible, surveillance on antibiotic resistance of APEC is very important. A total 34 APEC isolates from diseased chickens during the period from 2007 to 2009 were obtained. The susceptibility of the isolates to 13 antibiotics was determined by disc diffusion assay. Resistance to erythromycin was found in 97.1% of APEC isolated, followed by resistance to tetracycline (85.3%), doxycycline (82.3%), ampicillin (73.5%), sulfisoxazole (67.6%), enrofloxacin (67.6%), ciprofloxacin (64.7%), norfloxacin (61.7%) trimethoprim/sulfamethoxazole (52.9%), gentamycin (26.5%), amoxicillin (8.8%), colistin (5.9%), and amikacin (2.9%). The blaTEM genes were detected in 25 (100%) of the 25 ampicillin-resistant APEC isolates. Among the 29 tetracycline-resistant APEC isolates, tetA and tetB genes were detected in 18 (62.1%) and 9 (31%) isolates, respectively. Twenty six (76.5%) isolates were multiresistant to at least 6 antibiotics and seven (20.1%) isolates were multiresistant to at least 10 antibiotics. This results indicated that multiple antibiotic-resistant APEC is widespread in chicken flocks in Korea.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1039-1046
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• 2005

The salt resistance of antibacterial activity and synergistic effect with clinically used antibiotic agents are critical factors in developing effective peptide antibiotic drugs. For this reason, we investigated the resistance of antibacterial activity to antagonism induced by NaCl and $MgCl_2$ and the synergistic effect of P20 with cefotaxime. P20 is a 20-residue synthetic peptide derived from a cecropin A (CA)-melittin(ME) hybrid peptide. In this study, P20 was found to have potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) strains without hemolytic activity against human erythrocytes. The combination study revealed that P20 in combination with cefotaxime showed synergistic antibacterial activity in an energy-dependent manner. We also confirmed the synergism between P20 and cefotaxime by fluorescence-activated flow cytometric analysis by staining bacterial cells with propidium iodide (PI) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (BOX). This study suggests that P20 may be useful as a therapeutic antibiotic peptide with synergistic effect in combination with conventional antibiotic agents.

• 약학회지
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• 제51권5호
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• pp.355-360
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• 2007

The essential oil fraction from the aerial parts of A. annua was analyzed by GC-MS. As the results, caryophyllene oxide (11.7%), caryophyllene (7.54%), camphor (7.32%), 1,8-cineol (4.98%), and borneol (3.99%) were confirmed as the main components of the oil fraction. The effects of this oil and its main components on antibiotic-susceptible and -resistant strains of Salmonella enteritidis and S. typhimurium were assessed. A. annua oil fraction significantly inhibited all strains of the two Salmonella species examined, with minimum inhibiting concentrations (MICs) ranging from 2.0 mg/ml to 8.0 mg/ml. Among the main components of the oil, borneol and camphor showed relatively strong inhibiting activity with MICs between 1.0 mg/ml and 4.0 mg/ml. The MICs of caryophyllene and caryophyllene oxide were higher than 16 mg/ml. The combination effects of the oils with kanamycin were evaluated using a checkerboard microtiter assay. Against S. typhimurium KCCM11862 and CCARM8009 strains, the oil fraction of A. annua, camphor, and 1,8-cineol exhibited significant synergistic with kanamycin with fractional inhibitory concentration (FIC) indices in the range of 0.085 to 0.375. In conclusion, a combination of kanamycin and A. annua oil or its main component, camphor, and cineol, may be useful for reducing the minimum effective dose of antibiotic required for the treatment of resistant S. typhimurium infections.

• 대한임상검사과학회지
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• 제46권4호
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• pp.136-139
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the severe nosocomial infectious agents. The traditional diagnostic methods including biochemical test, antibiotic susceptibility test and PCR amplification are time consuming and require much work. The Surface enhanced Raman spectroscopy (SERS) biosensor is a rapid and powerful tool for analyzing the chemical composition within a single living cell. To identify the biochemical and genetic characterization of clinical MRSA, all isolates from patients were performed with VITEK2 gram positive (GP) bacterial identification and Antibiotic Susceptibility Testing (AST). Virulence genes of MRSA also were identified by DNA based PCR using specific primers. All isolates, which were placed on a gold coated nanochip, were analyzed by a confocal Raman microscopy system. All isolates were identified as S. aureus by biochemical tests. MRSA, which exhibited antibiotic resistance, demonstrated to be positive gene expression of both femA and mecA. Furthermore, Raman shift of S. aureus and MRSA (n=20) was perfectly distinguished by a confocal Raman microscopy system. This novel technique explained that a SERS based confocal Raman microscopy system can selectively isolate MRSA from non-MRSA. The study recommends the SERS technique as a rapid and sensitive method to detect antibiotic resistant S. aureus in a single cell level.

• 공업화학
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• 제22권2호
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• pp.119-124
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• 2011

현재, 사람들은 많은 병에 노출되어 있다. 산업화의 빠른 변화는 생산시설의 자동화, 정보 통신 산업기술의 발달로 삶의 질이 향상되었으나, 신체활동의 감소와 환경오염으로 인해 환경적 스트레스와 병원균 감염 반응에 대한 인간의 면역체계가 악화되었다. 아울러 현재 약물의 오 남용으로 다재약물내성을 갖는 미생물들(multidrug-resistant microbes)과 암세포(tumor)의 출현으로 인해 새로운 항생제 개발이 시급하다. 그들 중 하나가 항생 펩타이드(antibiotic peptide)로 기존 약물과 비교하면 약물저항성이 거의 일어나지 않는다. 여러 가지 항생활성을 가지는 펩타이드들은 다양한 생명체로부터 동정되고 있다. 이 논문은 항생 펩타이드들의 활성과 적용분야에 대해 논하려 한다.

• 식물병연구
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• 제28권3호
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• pp.166-171
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• 2022

Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twenty-seven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 ㎍/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides-Buramycinand streptomycin at the concentration of 250 ㎍/ml that is recommended by the manufacturer for streptomycin-based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.

• 약학회지
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• 제51권4호
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• pp.253-258
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• 2007

Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

• 한국동물위생학회지
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• 제30권4호
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• pp.505-510
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• 2007

This study was conducted to detect ${\beta}$-lactam antibiotic-resistant genes in the 400 E coli isolates from porcine fecal samples in Korea by a DNA chip. The DNA chip contains the specific probe DNAs of the ${\beta}$-lactam antibiotic-resistant genes that had been labeled with a mixture of primer set designed to amplify specific genes (PSE, OXA, FOX, MEN, CMY, TEM, SHV, OXY and AmpC) using a multiplex polymerase chain reaction (PCR). Of 400 isolates 339 contained at least one ${\beta}$-lactamases gene. Resistance to ${\beta}$-lactamases was mediated mainly by AmpC (n = 339, 100%), and followed by TEM (n = 200, 59.0%), CMY (n = 101, 29.8%), PSE (n = 30, 8.9%) and both OXA and SHV genes (n = 20, 5.9%), while the FOX, MEN and OXY genes were not detected. The other sixty-one did not contain any ${\beta}$-lactamase genes even though they were resistant to antimicrobial drugs. In conclusion, the DNA chip system can be used as a rapid and reliable method for detecting of ${\beta}$-lactamases genes, which will help veterinarians select the antibiotics for monitoring and treating of animal diseases.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.246-253
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• 2004

The prevalence, genotype for antibiotic resistance and antibiotic susceptibility of vancomycin resistant enterococci (VRE) were determined. And molecular typings of the Enterococcus faecium isolates were analyzed. Prevalence of VRE in chickens, healthy children and intensive care unit (ICU) patients was 41.6％,7.9％, and 20.4％, respectively. Forty out of 54 isolates from chicken intestines, and 9 out of 11 from ICU patients were identified as Enterococcus faecium. Eleven out of 13 isolates from non-hospitalized young children were E. gallinarium. Twelve strains of E. faecalis were isolated from chicken intestines. The gene for the antibiotic resistance in E. faecium, and E. faecalis was vanA, while that in E. gallinarium was vanC1. E. faecium isolates were resistant to most of antibiotics except ampicillin and gentamicin. Molecular typing of the E. faecium strains obtained by pulse field gel electrophoresis and repetitive sequence-based PCR suggest that VRE transmit horizontally from poultry to humans, especially young children, via the food chains in Korea.