• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.243-246
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• 2005

A novel esterase showing high enantioselectivity to (S)-ketoprofen ethyl ester was selected from fosmid environmental DNA library which is provided by Microbial Genomic & Applications Center. As a result of Blast search, the gene wasn't registerated in Gene Bank yet. And as we know, conserved domain region of esterase , G-X-S-X-G, wasn't discovered.$^{4)}$ And it is similar to Beta-lactamase. The DNA sequence of cloned esterase include an open reading frame consisting of 1170 bp, designated as EST-Y29, encoding a protein of 389 amino acids with a molecular mass of about 42.8 kDa. And amino acid sequence analysis revealed only a few identity (28%) to tile known esterases/lipases in the databases containing the conserved sequence motifs of esterases/lipases. when being comparison to other esterase revealed , this enzyme seems to be classified as a new member of esterase family. EST-Y29 was functionally overexpressed in a soluble form in E. coli with maximum conversion yield of (S)-ketoprofen at $65^{\circ}C$. This study demonstrates that functional screening combined with the sequential uses of restriction enzymes to exclude already known enzymes is a useful approach for isolating novel enzyme from a metagenome.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.166-173
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• 1992

The expression of Bacillus subtilis $\alpha$-amylase from the phoA-amyE fusion gene in recombinant E. coli was investigated under various environmental conditions. The overexpression of cloned $\alpha$-amylase caused retardations in cell growth and synthesis of alkaline phosphatase (AP) from the chromosomal phoA gene. The change of culture temperature from $37^\circ{C}$ to $30^\circ{C}$ increased the specific activities of both $\alpha$-amylase and $\beta$-lactamase by six and two times, respectively, whereas the AP activity remained unchanged. The experiments with chlorampenicol (a translation inhibitor) suggested the enhancement of $\alpha$-amylase activity at $30^\circ{C}$, and this was partly due to the stability of $\alpha$-amylase itself. The further decrease of the temperature to $25^\circ{C}$ slowed down both the cell growth and cloned-gene expression rate. The $\alpha$-amylase activity showed a maximum at pH of 7.4 while alkaline phosphatase was most effectively produced at pH of 8.3.

• 대한수의학회지
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• 제57권1호
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• pp.9-15
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• 2017

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a ${\beta}-lactamase$ secretion system. This was then transformed into ${\Delta}asd$ ${\Delta}crp$ Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.

• 한국임상약학회지
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• 제23권1호
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• pp.26-32
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• 2013

Objective: This study was to define the clinical effect on the clinical decision support system (CDSS) for prescribing antibiotics integrated with the order communication system in a National Hospital. Method: We extracted data collected before integrating the CDSS of 4,406 adult patients in 2007 and data collected after integrating the CDSS of 4,278 adult patients in 2009. These patients were 50.4% and 45.2% of all patients admitted in 2007 and 2009, respectively. The clinical effect was defined as the proportion of prescribed antibiotics, the length of antibiotics use, and the DDDs (defined daily doses) of antibiotics per 1,000 patient-days using these retrospective data. Results: There were a significant change in the proportion of patient prescribed penicillins with extended spectrum (OR=0.55, p=001), penicillins included beta-lactamase inhibitors (OR=0.75, p<.001), 3rd cephalosporin (OR=1.47, p<.001). The mean of the length of antibiotics use was decreased statistically from $6.09{\pm}5.48$ to $5.85{\pm}5.51$ days (p=.003). The DDD of glycopeptides was decreased from 24.43 DDD to 19.55 DDD per 1000 patient-days. The DDD of 3rd cephalosporins was also decreased from 15.88 to 11.65. Conclusion: Therefore, the clinical decision support system for prescribing antibiotics was effective for the clinical outcomes.

• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.465-472
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• 2019

Several reports describe antimicrobial-resistance transfer among children and the community in outbreak situations, but transfer between a child and a caregiver has not been examined in child care facilities under normal circumstances. We investigated the transfer of antimicrobial-resistance genes, resistant bacteria, or both among healthy children and teachers. From 2007 to 2009, 104 Escherichia coli isolates were obtained from four teachers and 38 children in a child care center. Twenty-six cephem-resistant isolates were obtained from children in 2007 and 2008. In 2009, cephem-resistant isolates were detected in children as well as a teacher. Nalidixic acid-resistant isolates from the same teacher for 3 years showed low similarity (<50%) to each other. However, an isolate from a teacher in 2007 and another from a child in 2008 showed high similarity (87%). Pulsed-field gel electrophoresis revealed 100% similarity for four isolates in 2007 and one isolate in 2008, and also similarity among seven isolates carrying the virulence gene (CNF1). This study yielded the following findings: (1) a gene for extended-spectrum ${\beta}$-lactamase was transferred from a child to other children and a teacher; (2) a nalidixic acid-resistant isolate was transferred from a teacher to a child; and (3) a virulent bacterium was transferred between children.

• 디지털융복합연구
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• 제14권10호
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• pp.349-354
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• 2016

다양한 extended-spectrum ${\beta}$-lactamase (ESBL)를 생성하는 폐렴막대균의 출현 및 확산은 세균에 의한 감염증 치료에 어려움을 가중시키고 있다. 본 연구에서는 충청지역에서 분리된 폐렴막대균을 대상으로 ESBL 유전자를 검출하고 항균제 감수성 양상을 조사하였다. 또한 같은 클론에서 유래하였는지를 확인하기 위해 repetitive element sequence-based (REP)-PCR을 수행하였다. 충청지역에서 분리된 폐렴막대균 102균주 중 21균주가 CTX-M-14 및/또는 CTX-M-15를 생성하는 것으로 나타났으며 이 균주들은 3세대 cephalosporin 계열 항균제에 대해 70% 이상의 높은 내성율을 보였다. 본 연구에서 분리된 CTX-M형 ESBL생성 폐렴막대균은 다양한 클론으로부터 유래되었으며 그 중 일부는 지역사회에 확산되어 있음이 확인되었다. 이러한 폐렴막대균의 감염 및 확산을 방지하기 위해서는 감염관리의 강화가 필요하다. 아울러 좀 더 효과적인 내성세균의 관리를 위해서는 내성유전자의 생물학적 조사와 통계학적 분석을 통해 통합적으로 구축된 데이터베이스를 모니터링 할 필요가 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.421-426
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• 2014

To characterize the extended-spectrum beta-lactamases (ESBLs) in diarrheagenic Escherichia coli from Korea in 2008-2011, we screened seven enterotoxigenic E. coli (ETEC) and one enteroaggregative E. coli (EAEC) that produce ESBLs from a nationwide survey. All eight isolates produced CTX-M-type ESBLs, including CTX-M-12 (n = 4), CTX-M-14 (n = 2), and CTX-M-15 (n = 2). PCR-based replicon typing indicated that the $bla_{CTX-M-12}$ genes of four ETEC isolates were carried on a conjugative IncF plasmid, whereas the $bla_{CTX-M-14}$ of one EAEC was located on an IncK plasmid. This is the first report of the occurrence of $bla_{CTX-M}$ genes in clinical isolates of EAEC in Korea. The ESBL-producing isolates were shown to be different based on pulsed-field gel electrophoresis and multilocus sequence typing, whereas the four isolates with CTX-M-12 were clonally related. These observations raise an alarm for the spread of plasmid-mediated resistance to ESBL among diarrheagenic E. coli.

• 대한임상검사과학회지
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• 제44권2호
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• pp.81-85
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• 2012

This study was undertaken to evaluate phenotypic and genotypic methods for detection of Metallo-Beta-Lactamases (MBLs) among nosocomial Pseudomonas aeruginosa. Of the 50 P. aeruginosa isolates from clinical specimens, 20 were evaluated for carbapenem resistance and screened for MBL by double-disk synergy test and combined-disk test. Nineteen strains (95%) were found to be MBL producers among the 20 P. aeruginosa. MBL positives were further confirmed by Polymerase Chain Reaction (PCR). For the IMP and VIM types of MBLs, PCR analysis was performed on 19 of the 20, and 10 were positive for VIM MBL type. This study reports the validation of a simple and accurate MBL detection method that can be easily incorporated into the daily routine of a clinical laboratory. Early detection of MBL-carrying organisms, including those with susceptibility to carbapenems, is of paramount clinical importance, as it allows rapid initiation of strict infection control practices as well as therapeutic guidance for confirmed infection.Key Words : Hepatitis A virus (HAV), Anti-HAV, Hospital workers, Prevalence, Vaccination

• Clinical and Experimental Pediatrics
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• 제48권10호
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• pp.1107-1115
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• 2005

목 적 : ESBL 생산 S. sonnei에 의한 장염의 대규모 발생은 과거 국내는 물론 세계에서도 유래를 찾아볼 수 없었다. 저자들은 집단 발생한 ESBL 생산 S. sonnei에 의한 장염 환자의 임상적 특징과 치료에 대한 반응 등을 분석하여 ESBL 생산 S. sonnei 감염증에 대한 치료 지침을 마련하는데 도움이 되고자 한다. 방 법 : 연구 대상은 2004년 11월 충주 ${\bigcirc}{\bigcirc}$초등학교를 중심으로 집단 발생한 급성 장염 환자 중 분변 배양 검사상 S. sonnei가 검출되어 치료받은 환자 103명을 대상으로 하였다. 환자에서 분리된 S. sonnei에 대해 항생제 감수성 검사와 DNA 염기 서열 검사를 시행하였고, 환자들의 임상적 특징과 검사 소견, 그리고 항생제에 대한 반응 등을 후향적으로 분석하였다. 결 과 : 임상 증상은 발열 96.1%, 설사 93.2%, 복통 76.7%, 두통 71.8%, 구토 65.0%, 그리고 구역 41.7% 순으로 나타났다. 발열은 평균 2.0일간 지속되었고, 설사는 평균 3.9일간 지속되었다. 설사의 양상은 수양성 설사는 69%, 점액성 설사는 26%, 그리고 혈변은 5%에서 관찰되었다. 말초 혈액 검사에서 백혈구 증다증을 보이는 경우는 53.4%이었고, 혈청 검사에서 CRP 양성을 보이는 경우는 78.6%이었다. 대변 직접 도말 검사에서 백혈구가 고배율 당 50개 이상인 경우가 11.7%, 그리고 5-20개인 경우 9.7%이었다. 대변 잠혈 반응은 71%에서 양성이었다. 본 유행에서 분리된 ESBL의 유형은 염기 서열을 분석한 결과 CTX-M-14 유형으로 밝혀졌다. 항생제 투여에 대한 미생물학적 치료 결과는 ciprofloxacin 투여자 중 100%(9/9), azithromycin 투여자 중 100%(5/5), cefdinir 투여자 중 6.9%(5/72), ceftriaxone 투여자 중 0%(0/8), ceftizoxime 투여자 중 12.5%(1/8), TMP/SMX 투여자 중 0%(0/8), ampicillin/sulbactam 투여자 중 42.9%(3/7), amoxicillin/clavulanic acid 투여자 중 20%(1/5), 그리고 imipenem/cilastatin 투여자 중 68.8%(11/16)에서 추적 검사상 음전 되었다. 결 론 : 소아에서 발생한 ESBL 생산 S. sonnei에 의한 세균성 이질에 대한 항생제 선택에서 비용-효과 면이나 안전성 면에서 azithromycin이 매력적인 일차 선택약일 수 있을 것으로 사료된다. Ciprofloxacin은 비용-효과 면에서는 우수한 약제일 수는 있으나 소아에서의 사용은 아직 이르다고 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제74권2호
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• pp.63-69
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• 2013

Background: Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx). Methods: We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation. Results: During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum ${\beta}$-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%). Conclusion: Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.