• Bulletin of the Korean Chemical Society
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• 제10권2호
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• pp.185-190
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• 1989

Geometries for a number of representative ${\beta}$ -lactam antibiotics (penams, cephems and monobactams) have been calculated by computer graphics/molecular mechanics energy minimization procedures using both MM2 and AMBER force fields. The calculated geometries have been found in reasonable agreement with the geometries reported in the X-ray crystal structures, especially in terms of the pyramidal character of the amide nitrogen in the ${\beta}$-lactam ring and the Cohen distance. Based on these calculations, it is suggested that the nitrogen atom in the monobactams may also have pyramidal geometries in the biologically active conformations.

• 대한화학회지
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• 제43권4호
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• pp.8-489
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• 1999

• 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.

• 미생물학회지
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• 제43권2호
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• pp.116-123
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• 2007

본 연구는 부산지역 하천에서 plasmid 매개성 광범위 ${\beta}-lactam$ 분해효소(extended spectrum ${\beta}-lactamase;\;ESBL$)를 생성하는 세균을 분리하여 생성된 광범위 ${\beta}-lactam$ 분해효소를 유형별로 분류하기 위함이다. Escherichia coli 6균주와 Klebsiella pneumoniae 15균주가 피전달균주인 Escherichia coli J53 $Azid^{R}$에 plasmid 매개성 광범위 ${\beta}-lactam$ 분해효소 생성 인자를 전달하였다. PCR 후 얻은 유전인자를 plasmid로 매개된 광범위 ${\beta}-lactam$ 분해효소 유전자의 염기서열 분석결과, E. coli와 K. pneumoniae 유전자를 BCM Search Launcher 및 GenBank nucleotide database를 통하여 검색한 결과 ESBL 유형은 TEM-52형과 SHV-12형이었다. TEM-52는 E. coli와 K. pneumoniae 양쪽에서 분리되었다. 그러나 SHV-12는 K. pneumoniae에서만 분리되었다. 이상의 결과로부터 plasmid 매개성 광범위 ${\beta}-lactam$ 분해효소를 생성하는 세균이 한국에서는 이미 임상범위를 넘어 자연계까지 확산되었음을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.363-368
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• 1988

반합성 베타 락탐 항생물질의 가수분해 및 합성을 촉매하는 효소인 $\alpha$-acylamino-$\beta$-lactam acylhydrolase(ALAH)의 유전자를 Acetobacfer turbidans로부터 클론화하기 위한 연구를 수행하였다. 우선 순수 분리 정제된 효소에 대한 항혈청 (폴리클론 항체)을 제조한 다음 이를 probe로 하여 면역화학적 방법으로 유전자의 선별을 시도하였다. 이러한 용도로 개발된 운반체인 λ gtll에다 A. turbidans의 유전자 단편들을 삽입하여 genomic library를 제조한 후 이 library에서 유전자를 선별한 결과 두개의 positive clone을 얻을 수 있었다. 그러나. 이 두 clone들은 면역화학적으로 서로 다른 반응을 나타내었는데, 그 중 하나는 효소의 항혈청과는 잘 결합하나 융합되어진 베타 갈락토시다아제에 대한 항체와는 잘 결합하지 못하였고(λ gtll dn1), 또 다른 clone 은 이와 반대의 양상을 보여주었다(λ gtll dn2). 더구나 이들 clone을 여러 제한효소들로 분석해본 결과, 유전자가 삽입된 부분인 Eco RI 부위중 하나가 없어진 것을 알 수 있었다. 따라서 A. turbidans의 효소에 대한 유전자가 λ gtll에 클론화 되었으나 이 유전자와 베타 갈락토시다아제의 유전자(lacZ)간에 염기배열상 동위성이 있은 부위가 존재하여 재조합된 λ gtll 파지의 복제과정에서 삭제되어진 것으로 간주되어진다.

• Journal of Yeungnam Medical Science
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• 제27권1호
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• pp.8-17
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• 2010

It is important to select appropriate antimicrobials for the treatment of infection according to the results of antimicrobial susceptibility tests (ASTs), yet the clinical isolates are sometimes susceptible to antibiotics that are clinically ineffective or this is due to technical error of the ASTs. So, interpretive reading of ASTs is needed and especially for the ${\beta}$-lactams for treating $Enterobacteriacae$. This review describes the interpretive reading of ASTs according to natural antimicrobial resistance and the mechanisms of mechanisms, with giving special attention to the antibiotics phenotypes for $Enterobacteriacae$. Further, as all the diffent tissues have a different antimicrobial concentration for identical antimicrobials, more information is needed on the antimicrobial tissue distribution for the appropriate treatment of infection. (ED note: I hope you send me the paper.)

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.698-706
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• 2004

$\beta$-Lactam antibiotics such as penicillin G, amoxicillin, and ampicillin were determined by a potentiometric biosensor system which exploited penicillinase immobilized on Immobilon cellulose nitrate membrane and a flat-bottomed pH electrode-as the biological component and transducer. The optimum reaction buffer for maximum sensitivity was found as 2 mM of sodium phosphate buffer (pH 7.2). The detection limit of the biosensor could be extended to 1 $\mu{M}$ of the analytes by increasing the enzyme loading for immobilization to 100 units/$m\ell$. The model samples spiked with each of the standard penicillins were measured for their biosensor responses and HPLC peak area, resulting in the relative responses of 82.1-103.5% and 79.5-106.1% for the biosensor method along with HPLC analysis, respectively. This result showed a good precision of the current biosensor method for screening the penicillin compounds.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.75-79
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• 1991

A series of compounds, N-(2-substituted-1-carboxy)vinylazetidinones were successfully synthesized in order to test the hypothesis that biological activities of ${\beta}$-lactam antibiotics could be attributed to the smooth flow of electrons after a nucleophilic attack at the carbonyl carbon in the ${\beta}$-lactam ring. After introduction of aminothiazolylacetamido group at 3-position of the azetidinones, their biological activities were evaluated. Their low activities led to the conclusion that the smooth electron flow in ${\beta}$-lactams in not the sufficient source for the biological activities.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.398-401
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• 1988

$\beta$-lactamase을 저해하는 물질을 생성하는 방선균의 일균주를 토양에서 분리하였다. 분리된 균으로부터 $\beta$-lactamase 저해물질을 생산하는 조건을 검토하였고, 아울러 배양액에서부터 동 물질을 분리정제하여 그 특성의 일부를 조사하였다. 그 결과 이 물질은 $\beta$-lactam ring을 가지고 있지 않았으며, $\beta$-lactam 항생물질에 대한 내성을 나타내는 E. coli 내성균주에 강한 항생력을 나타냄을 알았다.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1591-1593
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• 2008