• YAKHAK HOEJI
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• v.43 no.6
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• pp.782-788
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• 1999

7-Oxocephalosporanate 1 was treated with phosphonium salts 2~4 by Wittig reaction to afford 7-exomethylene cephalosporanates 5~7. They were oxidized to sulfones 8~10 with mCPBA. Deprotecton of benzhydryl 7-exomethylene cephalosporanate with $AlCl_3$ and NaHCO_3$ gave sodium salts of 7-exomethylene cephalosporanates 11~16. The ${\beta}-lactamase$ inhibitory activity of synthesized compounds 11~16 were compared with sulbactam, tazobactam and clavulanic acid against Type I, II, III, IV and TEM-2 $\beta$-lactamase in vitro. Compound 15 showed more potent activity than sulbactam and clavulanic acid against Type III, IV ${\beta}-lactamase$ enzyme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.740-744
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• 2014

In this study, the ${\beta}$-lactamase (VPA0477) gene was used as a new target for the PCR-based detection of Vibrio parahaemolyticus. Primers specific for the ${\beta}$-lactamase (VPA0477) gene of V. parahaemolyticus, were designed and incorporated into a PCR-based assay. The assay was able to specifically detect all of the 191 V. parahaemolyticus strains tested, but did not result in amplification of 39 other Vibrio spp. and non-Vibrio spp. strains tested. The detection limit of the assay was 10 CFU of V. parahaemolyticus RIMD2210633 from pure culture broth. The ${\beta}$-lactamase (VPA0477) gene-based assay developed in this study was sensitive and specific, and has great potential for the accurate detection and identification of V. parahaemolyticus in seawater or seafood samples.

• 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.

• Journal of the Korean Chemical Society
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• v.49 no.5
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• pp.461-469
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• 2005

• Biomedical Science Letters
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• v.22 no.2
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• pp.29-36
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• 2016

Among the several agents causing carbapenem resistance of Acinetobacter baumannii, the most common cause is OXA-23 ${\beta}$-lactamase, which is known to hydrolyze carbapenem. To effectively control dissemination of carbapenem-resistant Acinetobacter baumannii (CRAB), development of both rapid and easy-to-use detection methods are required. The aim of this study is to develop a novel immunochromatographic assay (ICA) for rapid detection of OXA-23 ${\beta}$-lactamase. Of the seven monoclonal antibodies (mAbs) screened by ELISA, four mAbs (4G6, 4H6, 6G4, 9A4) exhibited high reactivity. Of these four specific antibodies, the combination of 6G4/4G6 showed the greatest reactivity and this combination of mAbs (6G4/4G6 mAbs) was used to develop the OXA-23 ${\beta}$-lactamase ICA. Of 102 A. baumannii isolates tested, the OXA-23 ${\beta}$-lactamase ICA results were consistent with PCR analysis except one false positive and one false negative isolate. The overall sensitivity and specificity were 98.36% and 97.56%, respectively. In conclusion, to the best of our knowledge, we have developed the first specific antibody set to detect OXA-23 ${\beta}$-lactamase using an ICA kit. This novel ICA can be used as a reliable and easy-to-use immunological assay for detection of OXA-23 ${\beta}$-lactamase producing CRAB in clinical laboratories.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.149-153
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• 1992

Cloning of the gene encoding extracellular .betha.-lactamase from Streptomyces sp. SMF13 in a plasmid pIJ702 and expression of the gene in Streptomyces invidans were carried out. Optimal conditions for the formation of protoplasts of S.lividans and the regeneration of the protoplasts were evaluated. Streptomyces sp. SMF-13 was selected as a donor strain of .betha.-lactamase gene and totla DNA of the strain was partially digested with Sau3A I. DNA fragments ranged from 4kb to 10 kb were ligated to pIJ702 AT Bgl II site and then the ligated DNAs were transformed to the protoplasts of S, livivans. The transformation efficiency was $2 *10^{3}$ .$\mu$g DNA for the ligated DNA mixture. One colony among a thousand colonies regenerated showed extracellular .betha.-lactamase and the size of the inserted DNA fragment was estimated to be 3.94 kb. The .betha.-lactamase activity in the culture broth of the recombinant strain was maximum at 3 days culture to be 1.0 unit/ml.

• 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.

• Journal of Life Science
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• v.20 no.8
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• pp.1214-1220
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• 2010

Imipenem-resistant bacteria were isolated from clinical specimens taken from hospitalized patients in Suncheon, Korea. Fifty-four isolates were phylogenetically analyzed based on 16S rRNA gene and gyrB gene sequence comparisons. Isolates were affiliated with Pseudomonas aeruginosa (30 strains; 55.6%), Acinetobacter baumannii (21; 38.9%), Enterobacter hormaechei (2) and Pseudomonas putida (2). Twenty-two isolates produced metallo-$\beta$-lactamase (MBL); 12 Acinetobacter baumannii strains, 7 Pseudomonas aeruginosa strains, 2 P. putida strains and 1 Enterobacter hormaechei strain. Antibiotic susceptibility of the isolates was determined using the disc diffusion method and Vitek system. Strains producing metallo-$\beta$-lactamase (type IMP & VIM) were more resistant to antibiotics ceftazidime, aztreonam, amikacin and gentamicin than to strains producing OXA and SHV type of $\beta$-lactamase.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.237-237
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• 1996

DA-1131, imipenem(IPM) 및 meropenem(MEPM)은 각종 $\beta$-lactamase를 산생하는 세균에 대하여 우수한 항균력을 나타내었으나 cefpirome(CPR), ceftazidime(CAZ) 및 azthreonam(AZT)의 경우에는 extended broad spectrum cephalosporinase 산생 균주를 포함하여 일부 균주의 내성획득이 확인되었다. DA-ll3l의 $\beta$-lactamase Inducible activity는 DA-1131, IPM 및 MEPM이 거의 동일하였으며, imipenemase 산생균주로 동점된 Serratia marcescens 11001이 산생하는 $\beta$-lactamase이외의 효소에는 대부분 가수분해되지 않는 결과를 나타내었다. S. marcescens 11001이 산생하는 $\beta$-lactamase에 대한 효소역학상수는 DA-1131, IPM 및 MEPM에서 모두 유사하였고, $\beta$-lactamase에 대한 affinity도 큰 차이를 나타내지 않았다.

• Journal of Life Science
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• v.19 no.12
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• pp.1718-1723
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• 2009

In this study, we characterized extended-spectrum $\beta$-lactamase (ESBL)-producing Enterobacteriaceae isolated from clinical specimens in Korea and found two strains harboring plasmid-mediated $bla_{SHV-11}$, Klebsiella pneumoniae. First, the isolates were detected using the Vitek system and confirmed by the double-disk synergy test. The classification of gene coding for ESBL was also performed by polymerase chain reactions and followed by DNA sequencing. The transmission of genes was confirmed by transconjugation and transformation. Resistant expression of transformants was determined by broth microdilution minimal inhibitory concentration test. Genotypic analysis revealed that one strain harbored the $bla_{TEM-1}$, $bla_{SHV-11}$ and $bla_{CTX-M-15}$ and the other strain harbored the $bla_{SHV-11}$ and $bla_{CTX-M-15}$. They showed high resistance to oxyiminocephalosphorins (3rd-generation cephalosporins), while the transformant containing only $bla_{SHV-11}$ did not show any resistance to the antibiotics.