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        검색결과 158

        81.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 해역의 수질오염 특성을 알아보기 위해서 2010년 2, 5, 8, 11월에 광양만 20개 정점과 진해만 23개 정점에서 COD (화학적산소요구량, Chemical Oxygen Demand), Chlorophyll a, 대장균 Escherichia coli를 조사하였다. 또한, 광양만과 진해만의 지형학적특성을 고려하여 각각 3개 구역, 4개 구역으로 나누어 평가하였다. 광양만의 COD농도는 춘계 (평균: 4.3 mg L-1))에 가장 높
        4,000원
        82.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, two duplex real-time PCR approach with melting curve analysis is presented for the detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus, which are important food-borne bacterial pathogens usually present in fresh and/or minimally processed vegetables. Reaction conditions were adjusted for the simultaneous amplification and detection of specific fragments in the β-glucuronidase (uidA, E. coli), thermonuclease (nuc, S. aureus), hemolycin (hly, L. monocytogenes) and tetrathionate reductase (ttr, Salmonella spp.) genes. Melting curve analysis using a SYBR Green I real-time PCR approach showed characteristic Tm values demonstrating the specific and efficient amplification of the four pathogens; 80.6 ± 0.9 ℃,86.9 ± 0.5 ℃, 80.4 ± 0.6 ℃ and 88.1 ± 0.11 ℃ for S. aureus, E. coli O157:H7, L. monocytogenes and Salmonella spp.,respectively. For all the pathogens, the two duplex, real-time PCR was equally sensitive to uniplex real-time PCR,using same amounts of purified DNA, and allowed detection of 10 genome equivalents. When our established duplex real-time PCR assay was applied to artificially inoculated fresh lettuce, the detection limit was 10³ CFU/g for each of these pathogens without enrichment. The results from this study showed that the developed duplex real-time PCR with melting curve analysis is promising as a rapid and cost-effective test method for improving food safety.
        4,000원
        83.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the antimicrobial resistance pattern and distribution of resistance gene determinants in fecal E. coli from chicken. Antimicrobial susceptibility test was performed on a total of 109 fecal E. coli isolates from chicken, collected in Gyeonggi, Chungbuk, Jeonnam and Jeonbuk province from March to November 2003, by the disk agar diffusion method. Eighteen commonly used antimicrobial agents approved in Korea as veterinary medicine were tested: ampicillin (AM), amoxicillin/clavulanic acid (AMC), cephalothin (CF), cefozolin (CZ), cefoxitin (FOX), cefotaxime (CTX), cefepime (FEP), imipenem (IPM), streptomycin (S), gentamicin (GM), amikacin (AN), ciprofloxacin (CIP), enrofloxacin (ENO), norfloxacin (NOR), trimethoprim/sulfamethoxazole (SXT), erythromycin (E), chloramphenicol (C) and tetracycline (TE). Higher resistance rates (≥50%) were observed against 9 antimicrobial agents including AM, CF, S, CIP, ENO, NOR, SXT, E and TE. Resistance was most frequent for TE in 105 E. coli isolates (96.3%). Twenty-two isolates (20.2%) of the isolates showed multiple antimicrobial resistance to 8, and 19 isolates (17.4%) showed to 7 antimicrobial agents. The distribution of the resistance gene determinants for S and TE was assessed by PCR in resistant isolates. Thirty isolates possessed the strA, strB, and aadA gene, 25 isolates possessed the strA and strB gene among the 66 streptomycin-resistant isolates. Fifty one isolates possessed only the tetA gene, 22 isolates possessed the tetA and tetB gene, 11 isolates possessed only the tetB gene among the tetracycline-resistant isolates.
        4,000원
        84.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Porphyromonas gingivalis lipopolysaccharide (Pg LPS) is an important virulence factor in chronic periodontitis. The aim of this study was to compare the expression of inflammatory cytokine genes in Escherichia coli LPS (Ec LPS) and Pg LPS-stimulated mouse macrophage RAW 264.7 cells. Cells were treated with Ec LPS and Pg LPS for 18 hours, and the cytokine gene expression profile was assessed using microarrays and confirmed by real-time PCR. Microarray analysis showed that both types of LPS induced a significant increase in the expression of IL-17β, IL-2, Ccl4, Cxcl2 and TNFα compared with the control. However, LT-b was up-regulated by Pg LPS but not by Ec LPS. Real-time PCR analysis of these genes showed similar results for LT-b, Ccl4, Cxcl2, and TNF- but found that IL-17β and IL-2 were upregulated by Pg LPS but not by Ec LPS. These data indicate that Pg LPS stimulates the transcription of IL-17β, IL-2, Ccl4, Cxcl2, LT-b, and TNFα, all of which may be involved in the pathogenesis of chronic periodontitis.
        4,000원
        85.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Porphyromonas (P.) gingivalis lipopolysaccharide (Pg LPS) is the major pathogenic component of periodontal disease. In this study, we have attempted to determine the expression profiles of the signal transduction pathway genes induced by Pg LPS in comparison with Escherichia (E.) coli LPS (Ec LPS). DC2.4 cells were treated for two hours with 1 μg/mℓ of Pg LPS or 0.5μg/mℓ of Ec LPS. The total RNA from these cells was then isolated and reverse-transcribed. Gene expression profiles were then analyzed with a signal transduction pathway finder GEArray Q series kit and significant changes in expression were confirmed by real-time PCR. The microarray results indicated that several genes, including Tnfrsf10b, Vcam1, Scyb9, Trim25, Klk6, and Stra6 were upregulated in the DC2.4 cells in response to Pg LPS treatment, but were downregulated or unaffected by Ec LPS. Realtime PCR revealed that the expression of Trim25, Scyb9 and Tnfrsf10b was increased over the untreated control. Notably, Trim25 and Tnfrsf10b were more strongly induced by Pg LPS than by Ec LPS. These results provide greater insight into the signal transduction pathways that are altered by P. gingivalis LPS.
        4,000원
        86.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        저온에서 미생물을 사멸시킬 수 있는 비열살균기술로 감압 플라즈마를 활용하고자 생성기체별 감압 플라즈마 특성을 비교하고 Escherichia coli 살균효과를 조사하였다. 1 Torr 이하로 감압시킨 상태에서 공기, 산소, 질소를 350 mL/min으로 공급하며 플라즈마를 발생시킨 결과 아크발생 없이 균일한 플라즈마가 생성되었다. 감압 플라즈마에 의한 온도 상승은 5분 처리 시 10oC 내외, 10분 처리 시 25oC 미만이었으며, 기체 종류별로는 공기, 산소, 질소 순으로 상승도가 낮았다. 감압 플라즈마 5분간 처리로 E. coli는 5 log 이상 감소하였으며, 이후 감소율이 둔화되어 10분간 처리 후 6-7 log 정도의 감소를 보였다. 감압 플라즈마에 의한 E. coli 살균패턴은 살균속도가 높은 초기와 낮은 후기로 구분되는 2단계 1차 반응으로 확인되었으며, 초기 살균속도상수(k1)는 공기, 산소, 질소 순으로 감소하였다. 감압 공기플라즈마 살균의 작은 D값 또한 식품 표면의 오염도를 낮추기 위한 비열살균기술로서의 가능성을 제시하였다.
        4,000원
        87.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was evaluated the antibacterial effect of the combination of Coptidis rhizoma,Lonicerae Flos, and Paeonia japonica (1:1:1) extracts (CLP1000). Also, the effectiveness of CLP1000, dioctahedral smectite (DHS), and the combination of CLP1000 and DHS (CLPS1000) against E. coli O157:H7 infection was studied using ICR female mice. During the incubation period, the dose of 10% and 20% CLP1000 were inhibited the growth of E. coli O157:H7 by 30% and 47%, respectively. For 7 days after single challenge with E. coli O157:H7, forty female ICR mice were divided into four experimental groups which were orally administered with saline, 10% CLP1000, 10% DHS, and 10% CLPS1000, respectively. On the 3rd day, the number of E. coli O157:H7 in mouse feces was significantly decreased by administration of CLP1000 (p < 0.05), DHS (p < 0.05) and CLPS1000 (p < 0.001). On the 7th day, CLP1000 (p < 0.05) and CLPS1000 (p < 0.001) administration significantly decreased the number of E. coli O157:H7. According to the results of the present study, administration of CLPS1000 to mice can reduce the severity of E. coli O157:H7 infection. Also, it is suggested that CLPS100 represents a good candidate for the treatment of enteric infections in domestic animals.
        4,000원
        90.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was practiced to survey food-borne bacterial aspects of Escherichia coli and Bacillus cereus etc. from 210 processed seasoned marine products in Garak fishery wholesale market in Seoul, 2009. Distributions of these bacterial isolates were 28 coliforms, 32 Bacillus spp., 71 Staphylococcus spp., 11 Listeria spp, and 10Enterococcus spp. in 157 dried squids, 23 dried file fishes, and 20 dried pollacks etc. respectively. Results in 16 kinds of antibiotics susceptibility test by disc diffusion method, special multiple drugs resistance patterns were NOR + LVX + CIP + SAM+ VA + S + TE + CF, SAM + C + VA, VA + S + TE, and VA + S in 9 E. coli strains, also,AMC + SAM + CF, SAM + CF, and VA + CF in 21 Bacillus cereus strains respectively. On the basis of the results above, many seasoned dried fishes had multiple drugs resistances, conclusively, we suggest limited guideline and special management on use of antibiotics in floating net cages of fishery farms.
        4,000원
        92.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to develop a model for describing the effect of storage temperature (4, 10, 15, 20, 25, 30 and 35℃) on the growth of Escherichia coli O157 : H7 in ready-to-eat (RTE) lettuce treated with or without (control) alkaline electrolyzed water (AIEW). The growth curves were well fitted with the Gompertz equation, which was used to determine the specific growth rate (SGR) and lag time (LT) of E. coli O157 : H7 (R2 = 0.994). Results showed that the obtained SGR and LT were dependent on the storage temperature. The growth rate increased with increasing temperature from 4 to 35℃. The square root models were used to evaluate the effect of storage temperature on the growth of E. coli O157 : H7 in lettuce samples treated without or with AIEW. The coefficient of determination (R2), adjusted determination coefficient (R2 Adj), and mean square error (MSE) were employed to validate the established models. It showed that R2 and R2 Adj were close to 1 (> 0.93), and MSE calculated from models of untreated and treated lettuce were 0.031 and 0.025, respectively. The results demonstrated that the overall predictions of the growth of E. coli O157 : H7 agreed with the observed data.
        4,000원
        93.
        2009.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자외선 살균소독기의 유효성을 검정하기 위하여 스테인리스스틸 컵 바닥에서 E. coli를 대상으로 살균력을 측정하고 살균패턴을 조사하였다. 스테인리스스틸 컵 바닥의 자외선 강도는 컵의 위치에 따라 큰 차이를 보였다. 중앙부에 놓인 컵의 바닥에서는 높은 자외선 강도를 보인 반면 외곽으로 갈수록 자외선 강도는 급격하게 약화되었으며, 이러한 편차는 상단 선반에서 가장 심하였고 중단 및 하단 선반으로 갈수록 완화되었다. E. coli를 대상으로 한 스테인리스스틸 컵 바닥에서 살균효과는 컵 바닥의 자외선 강도와 살균시간에 비례하였다. 자외선에 의한 E. coli 살균패턴은 tailing을 수반하는 의사 1차반응으로 나타났으며 각 구간의 살균속도상수를 산출한 결과 초기 살균속도상수(K1)는 위치에 따라 큰 차이를 보인 반면 후기 살균속도상수(K2)는 위치에 따른 차이가 크지 않았다. 현장에서 자외선 살균소독기를 용이하게 사용할 수 있도록 일정 살균치를 얻는데 필요한 자외선 조사시간을 산출하는 방정식을 제시하였다.
        4,000원
        94.
        2008.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Characteristics of commercial antimicrobial filter media for bioaerosol removal were estimated. A chitoasn/ medium filter, a catechin/HEPA filter, a silver/HEPA filter, a copper/pre filter, a electret cabin filter and a non-electret cabin filter were used for estimation. Filtration efficiency and antimicrobial efficiency was tested using Escherichia coli and Staphylococcus epidermidis. The electret cabin filter and the chitosan/medium filter showed the highest filtration and antimicrobial efficiency, respectively.
        4,000원
        95.
        2008.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis 1-3 (Bt 1-3), isolated from Korean soil sample, showed high insecticidal activity against Plutella xylostella. Recently, we improved plasmid capture system donor-s (PCS-S) by inserting attB sites including lacZ between transposable elements (designated as pTroy), to reduce background and construct E. coli-Bt shuttle vector. Through in vitro transposition with total plasmid DNA of Bt 1-3, at least 6 different size plasmids of Bt 1-3 were cloned. Among them, 47 clones which have approximately 10 kb plasmid in size were sequenced and 5 contigs were assembled. These contigs showed partial similarity with two known plasmids, pGI3 or pBMB175, separately. These cloned plasmids will acquire erythromycin resistance by BP recombination reaction with pDonrattPEm vector. After transformation into Bt cells, final erythromycin resistant Bt cell might contain novel E. coli-Bt shuttle vector. This scheme proposes that pTroy and pDonr-attPEm system can easily construct new shuttle vector by in vitro transposition, BP reaction, and erythromycin selection with any Bt plasmids.
        97.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        서울시 가락농수산물시장에서 수거한 총 2,066건의 해산물(어류 573건, 패류 721건, 갑각류 208건 그리고 연체류 564건)을 대상으로 대장균을 분리 동정한 결과 10.3%(212/2,066)의 검출율을 보였다. 분리된 212주의 대장균의 월별 분포를 살펴보면, 1월 4.0%, 2월 1.0%, 3월 0.7%, 4월 9.5%, 5월 4.4%, 6월 9.4%, 7월 30.5%, 8월 42.1%, 9월 21.2%, 10월 6.6%, 11월 0.7% 그리고 12월 4.6%의 검출율을 보여, 6-9월 등 하절기에 많은 대장균이 분포됨을 알 수 있었고, 검체별 분포를 살펴보면, 어류가 7.0%(40/573), 패류 12.8%(92/721), 갑각류 8.7%(18/208) 그리고 연체류 11.0%(62/564)의 검출율을 보여, 패류, 연체류가 어류, 갑각류에 비해 대장균 분리율이 비교적 높게 나타났다. 또한, 지역별 분포를 살펴보면, 강원 21.3%의 검출율을 보였고, 인천 15.6%,경남 12.1%, 전남 11.5%, 전북 22.2%, 충남 11.6%, 제주 6.7% 그리고 우리나라 이외의 지역에서 9.0%의 검출율을 보였다. 212주를 대상으로 혈청형 동정을 실시한 결과, O6은 소라, 키조개, 그리고 건해삼에서 각각 1건씩, O25는 문어, 멍게에서 각각 1건씩, O29는 소라, 키조개에서 각각 1건씩, 그리고 O8, O25, O26, O27, O55, O78, O126, O158, O168은 문어, 갈치, 미더덕, 바지락, 낙지, 쭈꾸미, 소라, 오징어 알에서 각각 1건씩, O167도 소라에서 1건 확인되어 총 16주 (7.5% = 16/212)의 O 혈청형이 동정되어 어패류 등 해산물에 대장균이 분포되어 있음을 알 수 있었다.
        3,000원
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