• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.22-22
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• 1996

In order to establish the structural requirements for designing new ${\beta}$-lactam antibiotics it is necessary to build the molecular model of a penicillin binding protein. D-alanyl-D-alanine carboxypeptidase/transpeptidase (DD-peptidase) is a good model for PBPs. The X -ray crystallographic structure of DD-peptidase has been reported at the 1.6${\AA}$ resolution. (omitted)

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.189-192
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• 1987

The syntheses of mercaptotetrazoles and cephalothin analogs are described. Their in vitro potency was established. The compounds exhibited high antibacterial activity against Gram-positive bacteria and moderate activity against Gram-negative bacteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2295-2302
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• 2014

The study aims primarily to evaluate the resistance of antibiotics and the prevalence of these enzymes among Escherichia coli the most frequent isolate of Enterobacteriaceae producing Extended-Spectrum ${\beta}$-Lactamase(ESBLs), to differentiate the types of enzymes in these isolates. Total 74(26.2%) Strains of producing ESBLs among the 282 E. coli isolates were isolated from hospitals of Chungcheong area (Daejeon, Chungnam, and Chungbuk) during a 6 month-period from February to July, 2013. 282 E. coli isolates including ESBL shown resistance rates of aztreonam 30.8%, Cefotaxim 30.9%, and Ceftazidime 32.2%, 74 isolates producing ESBLs in E. coli were resistant rates to Aztreonam 58.1%, Cefotaxim 100%, and Ceftazidime 63.5% of ${\beta}$-lactam antibiotics. CTX-M-2 (48 isolates) was the most prevalent type of ESBLs identified. Followed the order of frequency by PER-1 (28 isolates), VEB-1 (26 isolates) and CTX-M-8 (20 isolates), of the 74 isolates, 2 isolates only showed GES-1 in Chungnam province. Accurate identification type of ESBLs would aid in hospital infection control. This would give aid to the physician to prescribe more appropriate antibiotics.

• YAKHAK HOEJI
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• v.38 no.3
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• pp.322-331
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• 1994

For the development new cephalosporin antibiotics with aminothiazolmethoxyimino moiety in the C-7 position and triazolthiomethyl moiety in the C-3 position of cephem ring, $7{\beta}$-[(z)-2-(2-aminothiasol-4-yl)-2-(methoxyimino)acetamido]-3-[5-(aryl or het.)-4-phenyl-4H-1,2,4-triazol-3-yl]thiomethyl-3-cephem-4-carboxylic acids were synthesized. These compounds were tested for antimicrobial activitiy in vitro against ten species of microorganisms. It showed remarkable antibacterial activity against Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341 and Escherichia coli ESS. The antibacterial activity of most new compounds showed more active than cefazoline, but these compounds were lower active than cefotaxime against Pseudomonas aeruginosa IFO 13130.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.57-64
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• 1997

$Amino-{\beta}-lactam$ antibiotics are absorbed by the dipeptide transporter in the small intestine. These uptakes are coupled to a proton influx. The inward proton gradient is partly induced by the $Na^+/H^+$ exchanger and calcium ion is involved in control of this antiport. Interaction between ampicillin which is one of the $Amino-{\beta}-lactam$ antibiotics and nifedipine which is one of calcium channel blocking agents was studied in rats in vivo and with rabbit jejunum mounted on the Sweetana/Grass diffusion cells in vitro. Bioavailability of ampicillin was increased significantly when nifedipine was co-administered orally in rats. There were no differences in the distribution phase and the elimination phase when ampicillin was given either alone or with nifedipine intravenously. Conditions for in vitro experiments were determined. The lift rate of $O_2/CO_2$ gas was controlled to 3 bubbles/sec and ampicillin was stable in the Kreb's buffer at pH 6.0. Absorption of ampicillin was the greatest when the completely-stripped serosal membrane was used. Transport of ampicillin from mucosal to serosal side in the rabbit jejunum was enhanced by 32% in the presence of nifedipine (p=0.059). Above results suggest that nifedipine might increase the plasma level of ampicillin via the improved absorption in the intestine rather than the reduction in the elimination or/and alteration in the distribution.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.286-288
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• 2018

Moraxella osloensis NP7 was isolated from human skin of a collage male and showed resistance to ${\beta}-lactam$ and aminoglycoside antibiotics. Herein, we report the complete whole-genome sequence and gene annotations of M. osloensis NP7. It possesses single circular chromosome and seven plasmids. Chromosome is 2,389,582 bp in length with the G + C content of 43.9% and encodes 2,065 protein-coding genes. The combined seven plasmids are 654,202 bp in size with the average G + C content of 40.5% and code for a total of 667 protein-coding genes. The chromosome of NP7 strain contains four ribosomal RNA operon copies, one transfer-messenger RNA gene, forty-seven tRNA genes, three riboswitch genes and three CRISPR arrays. Additional CRISPR array is found in the plasmid pNP7-1. The genes conferring resistance to ${\beta}-lactam$ and aminoglycoside antibiotics were predicted to reside in the plasmid pNP7-1.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.146-149
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• 2009

Purpose: Foot infections are common complications in patients with diabetes. The patients are usually immune-compromised; therefore the pathogens could be resistant to narrow spectrum antibiotics. Those drugs, however, are categorized as specially managed antibiotics, and access are difficult without confirming of the pathogens. Our aim was to analyze the common pathogens in diabetic foot infection and figure out the proper antibiotics. Materials and Methods: We studied 68 patients treated with diabetic foot infection. The pathogens which caused the infection and their sensitivity to initial antibiotics were analyzed. We also investigated the change of the antibiotics after the confirming of the culture result and average time to get the result. Results: Among the 68 patients, 56 (82%) received cephalosporin and beta-lactam antibiotics. Only 12 (18%) who were confirmed the drug resistant pathogens from previous culture, were treated with broad spectrum antibiotics such as vancomycin and tazoperan. Average culture study time was 6 days. Methicillin-resistant staphylococcus aureus (MRSA) was cultured in 19 patients (28%), Methicillin-resistant coagulase negative staphylococcus (MRCNS) in 11 patietns (17%), pseudomonas in 11 patients (17%). Total 44 (65%) including 3 of other antibiotics resistant pathogen needed broad spectrum antibiotics. Thirty two patients (47%) were resistant to initial antibiotics.irt follow up culture, 2 MRSA and 2 MRCNS were found. The antibiotics resistant pathogens were confirmed in 48 (71%) patients at last. Conclusion: Diabetic patients with foot infection need proper antibiotics from initial treatment. The proper broad spectrum antibiotics should assigned to the patients from the first time without the confirming of the culture results.

• YAKHAK HOEJI
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• v.52 no.4
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• pp.306-310
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• 2008

In vitro ${\beta}-lactamase$ inhibitory activity of 6-benzothiazole penicillins (1, 2, 3 and 4) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of exomethylene compounds (3 and 4) was stronger than those of non-exomethylene compounds (1 and 2). The sulfide 3 showed stronger inhibitory activity than sulbactam, clavulanic acid andsimilar to tazobactam against ${\beta}-lactamase$ Type I enzymes. The inhibitory activity of 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III and IV enzymes. The in vitro antimicrobial activity of ampicillin or cefoperazone combined with 3 or 4 was stronger than those of ampicillin or cefoperazone alone against many ${\beta}-lactamase$ producing strains to show that compounds 3 and 4 have some synergistic effect. The synergistic activity of 3 and 4 was comparable to sulbactam in some ${\beta}-lactamase$ producing strains, but it was inferior to tazobactam.

• Biomolecules & Therapeutics
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• v.7 no.1
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• pp.44-53
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• 1999

The resistant strains due to the extended-spectrum $\beta$-lactamase (ESBL) were susceptible to cefatrizine combined with clavulanic acid. The purpose of this study was to evaluate the in vitro and in vivo antibacterial activities of cefatrizine/clavulanic acid (CTRZ/CV) combination at a ratio of 2 : 1 in comparison with cefaclor (CCLO), cefuroxime (CRXM), cefuroxime axetil (CRXMA) and amoxicillin/clavulanic acid (AMXCCV). CTRZ/CV showed good activity against laboratory strains of gram-positive and gram-negative bacteria and exhibited excellent antibacterial activity against $\beta$-lactamase-producing strains. The bactericidal activity of CTRZ/CV was superior to that of CCLO and CRXM, and almost equal to that of AMXCCV against the $\beta$-lactamase-producing strains. The in vitro results were substantiated. by in vivo mouse experimental infection studies with $\beta$-lactamase-producing and non-producing strains. In mixed experimental infection due to $\beta$-lactamase-producing and non-producing strains, the therapeutic efficacy of CTRZ/CV was superior to that of CTRZ, CCLO, CRXMA and AMXCCV. In respiratory tract infection in mice due to Klebsiella pneumoniae EB4O, CTRZ/CV was more erective than CCLO, CRXMA and AMXCCV and also more efficacious than CCLO, CRXMA and AMXCCV in urinary tract infection in mice due to Escherichia coli EB13. These results indicate that CTRZ/CV is a useful drug for the treatment of infection caused by $\beta$-1actamase-producing strains including ESBL-producing strains.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3644-3652
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• 2010

The metallo-$\beta$-lactamases ($M{\beta}Ls$) are clinically significant enzymes which readily hydrolyze most $\beta$-lactam antibiotics. Discovering potential inhibitors for the $M{\beta}Ls$ is an expensive, time consuming endeavor. Virtual screening can sieve out inhibitor candidates with incompatible features prior to synthesis, decreasing these costs. Using Autodock 4.0, the binding locations and energies of four previously-studied potential inhibitors and four additional compounds obtained from the National Cancer Institute (NCI) database were computationally calculated. Based on the docking models of these eight compounds, we then designed several hypothetical inhibitor structures, compounds A through F, and performed their respective docking experiments. The docking results for compound F showed that it binds to the zinc containing active sites with a lowest predicted binding energy of -6.70 kcal/mol, suggesting F is the most likely potential $M{\beta}L$ inhibitor.