• Journal of Microbiology and Biotechnology
• /
• v.20 no.1
• /
• pp.146-152
• /
• 2010

Streptomyces clavuligerus NRRL3585 produces a clinically important $\beta$-lactamase inhibitor, clavulanic acid (CA). In order to increase the production of CA, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene (gap) was deleted in S. clavuligerus NRRL3585 to overcome the limited glyceraldehyde-3-phosphate pool; the replicative and integrative expressions of ccaR (specific regulator of the CA biosynthetic operon) and claR (Lys-type transcriptional activator) genes were transformed together into a deletion mutant to improve clavulanic acid production. We constructed two recombinant plasmids to enhance the production of CA in the gap1 deletion mutant of S. clavuligerus NRRL3585: pHN11 was constructed for overexpression of ccaR-claR, whereas pHN12 was constructed for their chromosomal integration. Both pHN11 and pHN12 transformants enhanced the production of CA by 2.59-fold and 5.85-fold, respectively, compared with the gap1 deletion mutant. For further enhancement of CA, we fed the pHN11 and pHN12 transformants ornithine and glycerol. Compared with the gap1 deletion mutant, ornithine increased CA production by 3.24- and 6.51-fold in the pHN11 and pHN12 transformants, respectively, glycerol increased CA by 2.96- and 6.21-fold, respectively, and ornithine and glycerol together increased CA by 3.72- and 7.02-fold, respectively.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.3
• /
• pp.275-282
• /
• 1987

Strains of bacteria resistant to beta-lactam antibiotics have been increasing in number and are becoming troublesome in clinical medicine. The in vitro antibacterial activity of augmentin, a combination drug consisting of two parts amoxycillin to one part clavulanic acid, a potent beta-lactamase inhibitor, and their minimum inhibitory concentrations were determined by an agar dilution technique against ampicillin-resistant clinical isolates in Korea. Of the 226 strains tested, 140 strains(62%) were resistant to ampicillin. Among the 140 ampicillin-resistant strains, all Salmonella spp. Proteus spp. the majority of S. aureus and Shigella spp. were sensitive to augmentin. Ps. aeruginosa remained 100% resistant and there has been a considerable decline in resistant strains in E. coli and K. pneumoniae although a significant percentage of strains showed intermediate sensitivity. The minimum inhibitory concentrations of augmentin were ranged in $8{\mu}g/ml$ to $32{\mu}g/ml$ in most bacteria and all S. aureus were inhibited by $8{\mu}g/ml$. In our microbiological studies we have shown that augmentin is active against ampicillin-resistant strains of Staphylococci and Gram-negative bacteria. In this hospital there would appear to be a significant number of strains of E. coli and K. pneumoniae showing intermediate resistance to augmentin. Most of these strains should be susceptible to augmentin given by mouth or by the intravenous route depending on the concentrations of both amoxycillin and clavulanic acid obtainable in the various tissues.

• 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.49 no.5
• /
• pp.392-398
• /
• 2005

In this study, we evaluated the stability of amoxicillin (AMX) and clavulanic acid (CLA) in aqueous solution, and compared the stability of AMX and CLA in commercial combination products. In aqueous solutions, the degradation of AMX ($t_{90}=8.88\;day\;at\;10^{circ}C$) and CLA ($t_{90}=3.53\;day\;at\;10^{circ}C$) occurred rapidly. From the pH-rate profile, AMX and CLA were the most stable at the range of pH 5.5 and 6.0. After reconstitution of commercial dry syrups, the contents of AMX and CLA in suspensions were gradually decreased for 7 days. However, AMX and CLA in dispersible tablet were not changed at all. The contents of CLA in the dispersible tablet ($87.92\%$) and dry syrups (2.16 and $3.91\%$) were remained in the accel­erated stability test ($75\%\;RH,\;at\;40^{circ}C$) after 10 hours. And the colors of the dry syrups were rapidly changed from white to yellow. From these results, we concluded that the dispersible tablet could overcome the stability problems of dry syrups.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.116-120
• /
• 2006

We constructed four recombinant plasm ids to enhance the production of clavulanic acid (CA) in Streptomyces clavuligerus NRRL3585: (1) pIBRHL1, which includes ccaR, a pathway-specific regulatory gene involved in cephamycin C and CA biosynthesis; (2) pIBRHL2, containing claR, again a regulatory gene, which controls the late steps of CA biosynthesis; (3) pGIBR containing afsR-p, a global regulatory gene from Streptomyces peucetius; and (4) pKS, which harbors all of the genes (ccaR/ claR/ afsR-p). The plasmids were expressed in S. clavuligerus NRRL3585 along with the $ermE^*$ promoter. All of them enhanced the production of CA; 2.5-fold overproduction for pIBRHL1, 1.5-fold for pIBRHL2, 1.6-fold for pGIBR, and 1.5-fold for pKS compared to the wild type.

• 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).

• 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.

• Biomolecules & Therapeutics
• /
• v.7 no.3
• /
• pp.285-291
• /
• 1999

DA-7101 is a new combined formulation of cefatrizine:clavulanic acid (2:1) under development as oral abtibiotics. The general pharmacological properties of DA-7101 on central nervous, cardiovascular, gas-trointestinal and other organ systems were studied by oral administration, in vivo and in vitro. DA-7101 had no marked effects all tests studied such as general behavior, hexobarbital-induced sleeping, spontaneous activity, anticonvulsion, body temperature, acetic acid-induced writhing, rotarod performance, heart rate and blood pressure in cats, isolated ileum movement, intestinal transition, gastric juice secretion and urine volume and electrolytes in rats. But exceptionally at the highest dose of 900 mg/kg, DA-7101 increased hexobarbital-induced sleeping time, caused a slight hypotension and decreased the secretion of gastric juice. These results suggest that at the estimated clinical dose DA-7101 would not bring about any serious acute adverse effects clinically.

• Bioindustry News
• /
• v.11 no.2
• /
• pp.22-27
• /
• 1998

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.11a
• /
• pp.41-53
• /
• 1996