• KSBB Journal
• /
• v.11 no.4
• /
• pp.504-509
• /
• 1996

Promoters which are useful for constructing expression vectors for lactic acid bacteria were obtained from the chromosomal DNA of Lactococcus lactis ssp. lactis MG1363. pBV5030, a promoter-selection vector, replicates in L. lactis and Escherichia coli and carries a promoterless chloramphenicol acetyltransferase gene (cat-86). After examining E. coli transformants which grew on LB media containing chloramphenicol (Cm, 20$\mu\textrm{g}$/mL) , many MG1363 derived DNA fragments which encompass promoter sequences were identified. Some recombinant E. coli cells can grow at the Cm concentration of 1,000$\mu\textrm{g}$/mL. When plasmids from those highly resistant E. coli cells were purified and introduced into L. lactis ssp. lactis MG1614 cells by electroporation, lactococcal transformants showing Cm resistance were obtained. So far, five plasmids with different promoter inserts were introduced into L. lactis MGl614 cells. The maximum level of Cm resistance in L. lactis MG1614 transformants was quite low (20$\mu\textrm{g}$/mL) when compared with that observed in recombinant E. coli cells harboring the same plasmids.

• Korean Journal of Veterinary Research
• /
• v.20 no.1
• /
• pp.53-58
• /
• 1980

Antimicrobial susceptibility of 157 Gram-negative bacilli (90 Escherichia coli. 30 Enterobacter aerogenes, 18 Klebsiella pneumoniae, 12 Proteus spp., 3 Pseudomonas aeruginosa and 4 Alcaligenes faecalis) isolated from infected bovine udders was determined by the plate dilution method. Gentamicin and oxolinic acid at a concentration of $12.5{\mu}g/ml$ were very active to all of 157 Gram-negative bacilli tested, and 98% of these strains were susceptible to nalidixic acid at a concentration of $25{\mu}g/ml$. Most of the 90 Escherichia coli strains were inhibited by chloramphenicol, ampicillin and carbenicillin and carbenicillin at a concentration of $12.5{\mu}g/ml$. None of the Klebsiella pneumoniae strains were inhibited at a concentration of $50{\mu}g/ml$ of ampicillin and carbenillin, whereas all the species of Proteus resisted a concentration of $50{\mu}g/ml$ or higher tetracycline. All the 3 strains of Pseudomonas aeruginosa were highly resistant to streptomycin, kanamycin, Ampicillin, chloramphenicol, tetracycline and nalidixic acid.

• Korean Journal of Microbiology
• /
• v.28 no.4
• /
• pp.297-303
• /
• 1990

Secretion of Serratia marcescens nuclease by E. coli harboring pNUC4 was investigated. 29.2, 54.2 and 16.6% of total nuclease were observed in culture medium, periplasm, and cytoplasm of E. coli, respectively. To investigate the secretion mechanism of Serratia nuclease by E. coli, secretion kinetics of nuclease was examined in the presences of sodium azide, and energy metabolism inhibitor; procaine, an exoprotein processing inhibitor; and chloramphenicol, a protein synthesis inhibitor. In the presence of sodium azide, periplasmic unclease was gradually decreased and the extracellular nyclease was linearly increased according to the incubation time. Similar results were obtained in presences of procaine and chloramphenicol. From these results, we concluded that two transport processes are involved in nuclease secretion: secretion of nuclease through the inner membrane is occurred by an energy-dependent process and probably requiring precusor processing: secretion of nuclease through outer membrane does not require energy, de novo protein synthesis, and precursor processing.

• Korean Journal of Microbiology
• /
• v.26 no.3
• /
• pp.167-172
• /
• 1988

A genetic map of the IncP-1 group plasmid pKU10 has been prepared through the construction of recombinant plasmids containing various fragments of pKU10. Phenotypic analysis of these derivatives has identified the location of genes encoding resistance to ampicillin, tetracyclin, and chloramphenicol. The region involved in conferring resistance to ampicillin was located around two PstI sites that are 1.0Kb apart. The tetracyclin resistance gene was mapped on the region of HindIII E fragment and a part of HindIII D fragment, and the determinant for chloramphenicol resistance gene was localized on HindIII D fragment.

• Journal of the Korean Chemical Society
• /
• v.16 no.6
• /
• pp.329-333
• /
• 1972

Chloramphenicol molecule has an asymmetric carbon, so it has conformational isomer, namely, threo and erythro form. These two forms have great difference in biological activity, that is, only threo (-) form has biological activity. Semiempirical quantum mechanical treatments are applied to these molecules to explain the difference, using the extended Huckel theory. The theoretical predictions for the preferred conformation are in good agreement with the experimental results.

• YAKHAK HOEJI
• /
• v.33 no.2
• /
• pp.73-79
• /
• 1989

One hundred and sixteen strains of E. coli isolated from drainage in Seoul city in 1987 and 104 strains of E. coli isolated from stools of domestic animals in suburb of Seoul in 1987 were examined for susceptibilities to 10 antimicrobial agents by the agar dilution method. The susceptibilities of the two groups to each antimicrobial agent were compared and correlations in the antimicrobial susceptibility of the 220 strains of E. coli among the 10 antimicrobial agents were also analyzed. The frequency of resistance strains was highest to tetracycline with 77%, and followed by chloramphenicol, streptomycin, ampicillin, kanamycin and cephalosporin in the descreasing order, tanging from 62% to 10%. Strains resistant to tobramycin, nalidixic acid, gentamicin and amikacin occupied 3 strains, 2 strains, 2 strains and 1 strain respectively.

• Microbiology and Biotechnology Letters
• /
• v.11 no.3
• /
• pp.163-168
• /
• 1983

The penicillin resistant plasmid DNA was prepared from Streptomyces bobili YS-40, producing penicillinase, by the phenol extraction method and introduced into Bocillus subtilis IAM 12118 by the transformation procedure of Mahler method. The optimal pH and temperature on the transformation was 7.0, 3$0^{\circ}C$ respectively. Above 20 minutes contact of plasmid DNA and recipient cell was shown the high transformation frequency. The transformant of penicillin resistance was proportionally increased as increase of the DNA concentration. The addition of lysine in transformation system increased the transformation frequency about 6-fold and the addition of the chloramphenicol did not affect the transformation frequency.

• Korean Journal of Microbiology
• /
• v.25 no.4
• /
• pp.262-273
• /
• 1987

The replication region of the chloramphenical resistance plasmid pSBK203 of Staphylococcus aureus was cloned using pBR322 and pBD9 as vectors. Cloned replication tegion and chloramphenicol resistance gene were recombined to pBR322. The reconstructed vector behaved as a shuttle vector for E. coli and B. subtilis.

• Natural Product Sciences
• /
• v.25 no.1
• /
• pp.59-63
• /
• 2019

Hematopoiesis has a pivotal role in the maintenance of body homeostasis. Ironically, several hematological disorder caused by chemicals, drugs, and other environmental factors lead to severe bone marrow failure. Current treatments like stem cell transplantation and immunosuppression remain ineffective to ameliorate this diseases. Therefore, a newtreatment to overcome this entity is necessary, one of them by promoting the usage of medicinal plants. Thus, this study aimed to evaluate the hematopoiesis potency of S. javanica berries and leaves extracts in chloramphenicol (CMP)-induced aplastic anemia mice model. In this present study, several types of blood progenitor cell such as $TER-119^+VLA-4^+$ erythrocytes lineage, $Gr-1^+$ granulocytes, and $B220^+$ B-cell progenitor cells were evaluated by flow cytometry analysis. Accordingly, we revealed that S. javanica berries and leaves extracts significantly promoted $TER-119^+VLA-4^+$ erythrocytes lineage and $Gr-1^+$ granulocytes after exposed by CMP. Thus, these results suggested that S. javanica berries and leaves extracts might have hematopoiesis activity in CMP-induced aplastic anemia mice model.

• 동물약계
• /
• no.43
• /
• pp.2.1-2.1
• /
• 1997

[ $\cdot$ ]동물용의약품등 신규 수입자확인 $\cdot$동물용의약품등 수입자확인 취소 $\cdot$수입완제 국가검정 동물용의약품에 대한 조치 $\cdot$Chloramphenicol 제조관리 철저 $\cdot$요주의동물용의약품 취급요령고시(안) 입안예고