• Analytical Science and Technology
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• v.23 no.2
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• pp.119-127
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• 2010

An effective method for the simultaneous analysis of ${\beta}$-lactams from surface water was established. After solid-phase extraction with HLB (Hydrophilic Lipohilic Balance) cartridge at pH 2, seven ${\beta}$-lactams (amoxicillin, ampicillin, penicillin G, cefaclor, cefadroxil, cefatrizine and cephradine) were determined using LC/ESI-MS/MS. In this newly established method, correlation coefficients ($r^2$) of calibration curves for seven ${\beta}$-lactams in blank surface water appeared to be 0.9911~0.9995 in the concentration range of 0.01~1.0 ng/mL. The limits of detection (LODs) and the limits of quantificaiton (LOQs) in spiked surface water were shown to be 0.0003~0.0234 ng/mL and 0.0046~0.0778 ng/mL, respectively. The developed method is believed to serve as a rapid and reliable method for the qualitative and quantitative analysis of residual ${\beta}$-lactam antibiotics from aquatic environment.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.303-307
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• 2010

Acinetobacter baumannii 1625, a clinical isolate identified by Vitek and 16S rDNA sequence, showed an extended resistance to most ${\beta}$-lactams including imipenem, kanamycin, gentamicin, tobramycin, and cephalosporins of the third and fourth generations, and produced metallo-${\beta}$-lactamase (MBL) of IMP-1 type which is rare in Korea. The isolate contained a class 1 integron of about 2.5 kb in size and the integron included accA4 (aminoglycoside resistance gene), $bla_{IMP-1}$ (carbapenem resistance gene), and $bla_{OXA-2}$ (extended-spectrum ${\beta}$-lactam resistance gene) gene cassettes in order. The coexistence of IMP-1 type and OXA-2 type ${\beta}$-lactamase gene cassettes in an integron has not been reported in Korea. The transformed integron rendered the E. coli transformant resistant more than eight folds against imipenem, ampicilin, piperacillin, cefazolin, cefoperazone, and aztreonam comparing to the reference strain. This study clearly showed that the extended multi-drug resistance of A. baumannii 1625 was mainly due to the integron.

• 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.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.225-232
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• 2000

Purpose : The use antimicrobial agents is one of the important strategies for the treatment and prophylaxis of microbial infections. But injudicious abuse and misuse of antimicrobial agents is problem to add an extra weight on medical fee, increase of resistant bacteria and side effects according to the antibiotic use. This study was performed to establish the pertinent use of antimicrobial agent in Chonbuk National University Hospital(CNUH). Characteristics of antibiotics use was analysis by reviewing the medical records of patients admitted to CNUH during the period of May 1998. Methods : One thousand eight hundred and thirty three patients were enrolled in this study(medical division 1,014 cases, surgical division 819 cases). Medical records were retrospectively reviewed to classify the rate of antibiotics use, name of antibiotics used, appropriateness of antibiotics use. Results : The overall rate of antibiotic usage in CNUH was 67.2%(1,231/1,833), showing higher rate in surgical division(89.6%) compare to that of medical division(49.0%). Among 1,231 patients to whom antimicrobial agents were given, only 125(10.2%) were treated with single antimicrobial agents. 311(25.3%) were treated with two antimicrobial agents, and 795(64.5%) patients received 3 or more antibiotics. ${\beta}$-lactams(56.4%) were most frequently used followed by aminoglycosides(35.3%), the others(4.9%) and quinolons(3.4%). Amoxicillin-clavulanate was the mostly commonly used antibiotics followed by amoxicillin and unasyn. Prophylactic use of antibiotics was carried in seven hundred six patients(57.4%), mostly in surgical division, which can be considered somewhat inappropriate in the initiation time and duration of antibiotic use. Conclusion : Importance of monotherapy and appropriate prophylactic antibiotic use should be emphasized. Strategies of antibiotics use, such as restriction of drug use, continuous monitoring system, flow sheet system should be considered to reduce antibiotics use and establish the appropriate use of antibiotics as well as inhibiting the occurrence of resistant strains.

• YAKHAK HOEJI
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• v.37 no.2
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• pp.158-162
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• 1993

6$\beta$-(trans-3-Aryl-5-oxo-pyrrolidin-2-yl)acetamidopenicillanic acid(7a~7c) and 7$\beta$-(trans-3-Aryl-5-oxo-pyrrolidin-2-yl) acetamidocephalosporanic acid(8a~8c) were synthesized and tested in vitro antibacterial activity. Of these new penicillins exhibited good antibacterial activity against Gram-positive bacteria whereas none of the compounds possessed the activity against Gram-negative bacteria at the concentration tested.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.17-17
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• 1992

항균성 물질을 이용한 화학 요법의 역사는 1930 년대 초 술폰아미드의 발견으로부터 비롯되었고, 페니실린의 발견 이래 $\beta$-lactam 계 항생제가 주종을 이루고 있다. 1963년 Lesher 와 Gruett 에 의해 합성된 nalidixic acid 가 요도염 치료제로 임상에 사용된 이후 이와 유사한 구조를 갖는 항균제 개발에 많은 연구가 진행되어 제 1세대, 제 2세대의 quinolone 개발에 이어 1950년대에 들어 제 3세대 quinolone의 개발이 활발히 진행되어 왔다. 제 3세대 항생제는 C-6 위치에 F기를 도입한 것으로 연구의 진행 방향은 항균력의 향상과 체내에서의 지속 시간의 연장, 경구 투여시 흡수로의 증가와 독성의 약화를 위한 것이다. 본 연구는 quinolone의 기본 골격을 유지하면서 C-7 위치에 새로운 group을 도입하여 그에 대한 항균력을 측정하여 새로운 quinolone계 항생제의 개발을 시도하였다.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.387-391
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• 2002

In vitro $\beta$-lactamase inhibitory activity of 6-exomethylene sulbactam compounds (CH-120, 130, 140, 145, 150, 155) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of CH-140 was stronger than sulbactam and clavulanic acid against Type II, III, IV, TEM enzymes and stronger than tazobactam against Type IV enzyme. The inhibitory activity of CH-145 was stronger than sulbactam and clavulanic acid against Type I, II, III, IV, TEM enzymes and stronger than tazobactam against Type III, IV enzymes. The in vitro antimicrobial activity of CH-140 and CH-145 combined with piperacillin and ceftriaxone was compared with the sulbactam and tazobactam against $\beta$-lactamase producing 31 strains. But, synergistic activity of CH-140 and CH-145 was inferior to tazobactam.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.456-460
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• 2003

In vitro $\beta$-lactamase inhibitory activity of 6-exomethylenepenam compounds ( 1, 2, 3, 4 and 5) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of compound 3 was stronger than those of sulbactam and clavulanic acid against Type I and II enzymes and stronger than tazobactam against Type III, IV, TEM enzymes. The inhibitory activity of 5 was stronger than sulbactam and clavulanic acid against Type I and II enzymes and stronger than tazobactam against Type III, and IV enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin and cefoperazone was compared with the sulbactam against $\beta$-lactamase producing 27 strains. But, synergistic activity of 3 and 5 was inferior to tazobactam.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.479-486
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• 2010

Tolerance against heat, sanitizers, and antibiotics of 112 Cronobacter isolates classified by desiccation was determined to permit effective biocontrol in powdered foods. The isolates were classified into three groups: dry-tolerant (n=37), dry-sensitive (n=7), and dry-intermediate (n=68). The strains that were highly tolerant to drying also showed high heat tolerance that they seemed to have high tolerance to heat after dry stress in powdered foods like infant formula. Sodium hypochlorite and benzalkonium chloride concentrations necessary to achieve a 5-log reduction in viable counts (CFU/mL) were 15-25 ppm and 5-15 ppm, respectively. However, there was little difference of the efficacy of these sanitizers between dry-sensitive and -tolerant strains for planktonic cells suspended in 3% albumin. The minimal inhibition concentration (MIC) of $\beta$-lactam ampicillin was 64-128 ppm for 90% of the strains. The isolates were consistently sensitive to kanamycin and naldixic acid (MIC=4 ppm). Dry-tolerant strains displayed more antibiotic resistance than dry-sensitive strains. The results indicate that dry-tolerant Cronobacter isolates often possess heat and antibiotic resistance, indicated the need for potent sterilization treatments of powdered foods.

• 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.