• Korean Journal of Microbiology
• /
• v.31 no.4
• /
• pp.274-278
• /
• 1993

Overproduced proteins in many cases result in forming insoluble inclusion bodies, and their formation might be due to high concentration of protein. To investigate how proteins become insoluble, chloramphenicol acetyltransferase (CAT) and .betha.-lactamase were overproduced, and their solubilities and activities were determined. CAT was accumulated from 9 to 45% of total cellular protein in a fully soluble form without inclusion body formation. CAT specific activity was shown to be proportional to the amount of the protein produced. Moderately produced .betha.-lactamase by the phase T7 expression system at 30.deg.C comprised only mature forms in a soluble form. However, overproduced .betha.-lactamase at 37.deg.C became insoluble. Most precursor forms of .betha.-lactamase in the cytoplasm were insoluble, whereas majority of the mature forms in the periplasm space were soluble. Also, chaperone GroE proteins which assist proper protein folding and translocation did not increase .betha.-lactamase solubility significantly under the experimental condition. It seems that the formation of inclusion bodies in the cell is related to the nature of protein itself rather than just to high concentration of protein.

• YAKHAK HOEJI
• /
• v.46 no.6
• /
• pp.387-391
• /
• 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
• /
• v.52 no.4
• /
• pp.306-310
• /
• 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.

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

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

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

• YAKHAK HOEJI
• /
• v.41 no.5
• /
• pp.658-665
• /
• 1997

Identification of a soil microorganism strain X-8, producer of ${\beta}$-lactamase inhibitor, based on its morphological, physiological, biochemical and chemotaxonomical characteristics was performed. The strain X-8 was identified as Pseudomonas sp. The beta-lactamase inhibitor produced by this strain was highly achieved in fermentation medium contained glucose 0.5%, urea 0.25%, $K_2HPO_4{\cdot}3H_2O\;0.5%,\;MgSO_4{\cdot}7H_2O\;0.5%,\;FeSO_4{\cdot}7H_2O\;0.01%,\;CuSO_4,\;ZnSO_4,\;MnSO_4\;0.02%$. The beta-lactamase inhibitor was not extracted by organic solvent such as n-butanol and ethyl acetate but remained in aqueous layer. The n-butanol extract showed antimicrobial activity against M. smegmatis. The ${\beta}$-lactamase inhibitor was stable at pH 7.0~8.0 and 4$^{\circ}C$ for 24h. The ${\beta}$-lactamase inhibitor was bound on ion exchanger Diaion WA-30 and HP-20 and eluted with 2N-$NH_4OH$ and acetone, respectively.

• YAKHAK HOEJI
• /
• v.49 no.1
• /
• pp.51-55
• /
• 2005

In vitro ${\beta}$-lactamase inhibitory activity of 6-triazole exomethylenepenam compounds (1, 2, 3, 4, 5 and 6) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of 3, 4 and 5 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type IV enzymes. And, inhibitory activity of 3 and 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin was better than those with sulbactam and with cefoperazone was compared with the sulbactam against ${\beta}$-lactamase producing 27 strains. The synergistic activity of (Z)-form compounds (3 and 5) was better than that of (E)-form compound (4) and sulfone compound (5) was better than sulfide compound (3).

• Korean Journal of Microbiology
• /
• v.42 no.2
• /
• pp.125-130
• /
• 2006

The emergence of extended spectrum ${\beta}$-lactamase producing bacteria is causing very serious problems in Korea. Although there have been many reports about these bacteria Isolated from patients and clinical specimens, there is no report of extended spectrum ${\beta}$-lactamase producing organisms isolated from natural environment in Korea. This study was conducted to investigate the biological characteristics and extended spectrum ${\beta}$-lactamase types of eighteen strains of extended spectrum ${\beta}$-lactamase producing Klebsiella pneumoniae and Escherichia coli isolated from a slaughterhouse in Pusan in Korea during 2002 to 2004. Extended spectrum ${\beta}$-lactamases were identified by double-disk synergy test, conjugation, isoelectric focusing values and gene sequencing. Eight strains of Klebsiella pneumoniae and two strains of Eschericha coli were isolated kom pigs and transferred extended spectrum ${\beta}$-lactamase genes to recipient Escherichia coli J53 (sodium azide resistant and ceftazidime senstive) strain by conjugation. The conjugants of extended spectrum ${\beta}$-lactamase genes were alignments and translated to amino acids by BCM and NCBI blast. Eight conjugants of Klebsiella pneumonae were typed TEM-52, and two strains of Escherichia coli, SHV-12, but CMY-1 type were not detected in this study.

• Journal of Life Science
• /
• v.20 no.5
• /
• pp.676-682
• /
• 2010

This study focused on typing of the extended-spectrum $\beta$-lactamase (ESBL) produced in organisms isolated from a natural environment, rather than a clinical setting. Samples were collected from drain water issuing from a sewage plant in Kwanganri (Busan, Korea). Following double disk synergy testing, 29 strains were selected as potential ESBL positive strains. Of these, 15 strains were transconjugants of the sodium azide resistant recipient strain Escherichia coli J53 and analyzed biochemically including indole, methyl-red, Voges-Proskauer, Simmon's citrate, decarboxylase-dihydrolase and sugar-fermentation tests. The tests classified the 15 strains as Klebsiella pneumoniae (n=13) and Escherichia coli (n=2). The type of ESBL from each strain was deduced by isoelectric focusing point analysis and DNA sequencing. The results indicated that the types of ESBL were SHV-12 (n=4) and SHV-12/TEM-1 (n=9) from K. pneumoniae and TEM-1 (n=2) from E. coli strains.