• Proceedings of the PSK Conference
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• 2003.10a
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• pp.85-87
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• 2003

$\beta$-Lactams are historically and clinically representative antibiotics used for therapeutic purposes. In early days, penicillin (penam antibiotic) and cephalosporin (cephem antibiotic) were found in culture broth of two different filamentous fungi, Penicillium chrysogenum and Acremonium chrysogenum. Since 1970, a variety of $\beta$-lactam structures have been discovered from bacterial cultures including Streptomyces species, which are known as cephamycin, cephabacin (cephem antibiotics), clavulanic acid (oxopenam antibiotic), thienamycin (carbapenem antibiotic), and sulfazecin (monobactam antibiotic). (omitted)

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.398-401
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• 1988

Streptomyces sp. producing $\beta$-lactamase inhibitor were isolated from soil. The culture conditions for the production of the $\beta$-lactamase inhibitor were evaluated and isolation produce of the $\beta$-lactamase inhibitor from the culture broth was also established. Some characters of the partially purified $\beta$-lactamase were determined.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.23-29
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• 1997

To develop novel cephem antibiotics, We have synthesized a new compound, named YH-487, by attaching the thiol and aminothiazole residue to $C_3$ and $C_7$ position of 7-ACA, respectively. Several characteristics such as structure, antibiotic spectrum, action mechanism, stability against ${\beta}-lactamase$ and synergistic effect were investigated. Anti-bactericidal activity of YH-487 against gram-positive and gram-negative bacteria were superior to that of the other cephem antibiotics. We have examined the action mechanisms of YH-487 using penicillin binding protein (PBP) assay, and found that the bactericidal activity was obtained by inhibiting PBP-1A, PBP-1B and PBP-3. YH-487 showed synergistic effect with gentamicin, tobramycin, and amikacin against Pseudomonas aeruginosa. In addition, YH-487 was effective against Enterobacter cloacae in combination with amikacin. Based on the above observations, YH-487 was classified as a novel third-generation ${\beta}-lactam$ antibiotics.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.33-33
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• 2003

There prevalence of $\beta$-lactamases bacteria in animals has been increased since 1990s [1]. The resistance in E coli which is mediated by $\beta$-lactamases hydrolyze the $\beta$-lactam ring eventually inactivate the antibiotics [2]. Generally, $\beta$-lactamases can be classified into four main groups and eight subgroups according to their functional and structural characteristics [3]. The detection of $\beta$-lactam antibiotic-resistant bacteria by DNA chip has been described [4]. The chip has a specific probe DNAs that contained the $\beta$-lactam antibiotic-resistant genes which was labeled by multiplex PCR reaction with a mixture of primer sets that were designed to amplify specific gene. Here we report the susceptibility of enteropathogenic E. coli isolated from pigs in Korea using the DNA chip in detecting $\beta$-lactam antibiotic-resistant genes. (omitted)

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.231-232
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• 1989

Although it has been known that organometallic $\beta$-lactam compounds improve the resistance to $\beta$-lactamases as well as their pharmacological activities, only a few results on organometallic $\beta$-lactam antibiotics were reported. In the course of our extensive study on the development of new cephalosporins, we were interested in organotin compounds since they show some biological activities.

• Korean Journal of Veterinary Service
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• v.30 no.4
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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.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.462-472
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• 1997

In this approach, the antimicrobial activities of the compounds were compared with the ${\beta}$-lactam antibiotics against ${\beta}$-lactamase producing strains in vitro. Heteroc yclyl exomethylenepenam derivatives were several numbers of 6-exomethylenepenam sodiums (CH1240, CH1245, CH1250, CH2140, CH2145, CH2150). The inhibitory concentraion assay of six compounds were compared with clavulanic acid, sulbactam, tazobactam. Clavulanic acid, sulbactam and tazobactam are used as inhibitors of a variety of plasmid-mediated beta-lactamases. In vitro ${\beta}$-lactamase inhibitory assay, CH1240 and CH2140 were more active than clavulanic acid, sulbactam and tazobactam against ${\beta}$-lactamases overally. And in vitro comparative antimicrobial susceptibility test of six inhibitors were performed with mixed forms of ampicillin, cefotaxime, amoxicillin, ticarcillin, piperacillin, cefoperazone against ${\beta}$-lactamase producing 31 species strains. Consequently CH2140 and CH1240 among the six compounds enhanced the activity of the ${\beta}$-lactams for 31 ${\beta}$-lactamase producing strains.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.234-238
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• 1992

Using cell-free extract of Lysobacter lactamgenus, enzymatic conversion of $\delta$-L-($\alpha$-aminoadiphyl)-L-cysteinyl-D-valine (ACV) the first substrate of $\beta$-lactam biosynthesis, into antibiotic compounds was attempted. In high performance liquid chromatographic (HPLC) analysis, the biosynthetic intermediates for cephalosporin antibiotics including isopenicillin N, deacetoxycephalosporin C, deacetylcephalosporin C and unknown cephem compound were detected in reaction mixtures. It implies that cephabacin compounds from L lactamgenus could be produced by biosynthetic routes through penicillin ring formation and its expansion to cephalosporin ring, likely as cephalosporin C from Cephalosporium or cephamycin C from Streptomyces. Among biosynthetic enzyme in cell-free extract, the ring formation activity (isopenicillin N synthetase activity) was separated in 50-60% of ammonium sulfate fraction, and ring expansion activity (deacetoxycephalosporin C synthetase activity) was found to be in 40-50% fraction. The partially purified isopenicillin N synthetase could convert as much as 90% ACV to isopenicillin N during 6-hour reaction.

• YAKHAK HOEJI
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• v.28 no.4
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• pp.243-248
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• 1984

For gas chromatographic determination with the sulfur-specific flame photometric detector, nine ${\beta}$-lactam antibiotics without ${\alpha}$-amino group were esterified with borontrifluoride-methanol complex and then N-benzoylated with benzoyl chloride. The gas chromatographic separation of these products was successfully carried out on various silicon polymers (OV-1, OV-101, OV-17, OV-225, and QF-1) coated on the acid washed, silanized diatomite. The structure of the esterified and N-benzoylated product was confirmed by mass spectromer.

• Korean Journal of Clinical Pharmacy
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• v.20 no.2
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• pp.145-150
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• 2010

In order to investigate the antibiotic prescription pattern for upper respiratory infections (URI), the prescription sheets for outpatients from July 2008 to June 2009 were collected from 7 community pharmacies in Ulsan City, and the prescription pattern of Pediatric and ENT physicians was analyzed. The antibiotic prescription rates of Pediatric and ENT physicians were 63.8% and 61.7%, respectively. It was also observed that the oral antibiotic prescription was 95.6% in Pediatrics and 97.6% in ENT. The most favorable antibiotics by Pediatric physicians were penicillins (21.5%) penicillin-clavulanate (36.4%) and cephalosporins (16.5%), macrolides (11.6%), quinolones (3.5%), and nifuroxazide (3.5%). In case of ENT, the commonly prescribed antibiotics were also penicillin-clavulanate (47.6%), cephalosporins (31.6%), macrolides (11.9%) and sulfonamide (1.3%). The antibiotic combination rate was 7.6% in Peditrics and 1.9% in ENT, among antibiotic prescriptions. The combination of more than two oral antibiotics was examined as 66.8% in Pediatrics and 44.2% in ENT. The common oral antibiotic combination in Pediatrics was prescriptions of two ${\beta}$-lactam antibiotics (54.3%). Among them 83% was the combination of amoxicillin-clavulanate (7:1) and amoxicillin, which could be judged as antibiotic overuse. The next highly prescribed oral antibiotic combination was ${\beta}$-lactam/macrolide antibiotic combination probably for URI (11.3%) and ${\beta}$-lactam/nifuroxazide combination (10.0%) presumably for acute diarrhea. Comparatively the oral antibiotic combination prescribed by ENT physicians was negligible except one physician. In conclusion, the antibiotic over-prescription rate by antibiotic combination was much higher in Pediatrics than ENT, even though both clinical departments showed nealy the similar antibiotic prescription rates.