• Archives of Pharmacal Research
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• 제12권4호
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• pp.249-253
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• 1989

High producers or blocked mutants of aminoglycoside antibiotic-producing Streptomyces spp. were selected by application of an agar plug method and by culturing individual colonies in broth. The productivities of aminoglycoside antibiotic producing organisms were increased by selection of a high producer from colonies obtained by spreading spores of wild strain, or survived from treatment of a mutagen or from the colonies regenerated from protoplast-formation and cell-wall regenerations. Some mutagen treated colonies lost the ability to produce antibiotics (5-8%). Some A-factor negative and deostreptamine or streptidine negative mutants were obtained by N-methyl-N'-nitro-N-nitrosomethylguanidine (MNNG) treatment. Many of the survivors from the MNNG treatment lost the ability to produce antibiotics. Major colonies produced less amount of antibiotics ; only few survived colonies produced more antibiotics than the parent. Resistance of Streptomyces spp. against the antibiotics produced by itself was also markedly affected by mutagen treatment.

• 한국미생물·생명공학회지
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• 제27권3호
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• pp.215-222
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• 1999

Methylotrophic actinomycetes No. 155 produced an aminoglycoside antibiotics(AG)-resistant inhibitor. We have previously reported that the inhibitor shows strong inhibition to sisomicin-resistant strain. In order to understand the functions of inhibitor and sisomicin-resistance, characterizations and purification of inhibitor were investigated. Strain No. 155 was tentatively identified as Nocardiopsis sp. based on morphological and some physiological characteristics. In the antimicrobial activity test, the addition of inhibitor to sisomicin showed a reduction effect of MIC on the test strains such as Gram(+), Gram(-) bacteria and yeasts. The combination of the inhibitor and various antibiotics revealed synergistic against E. coli K-12 and B. subtilis PCI 219. The induced intracellular proteins from sisomicin-resistant strain exhibited the sisomicin inactivation by invitro test. And the induced intracellular proteins were inactivated by addition of the inhibitor. The inhibitor compound was purified by anion exchange chromatography(Dowex-1) and HPLC using Asahipak ES-502C column. The purified inhibitor compound was detected in a single peak(above 98.5% purity) through the HPLC analysis.

• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.109-117
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• 2006

The Rev binding to Rev Responsive Element (RRE) of HIV-1 mRNA plays an important role in the HIV-I viral replication cycle. The disruption of the Rev-RRE interaction has been studied extensively in order to develop a potential antiviral drug. In order to provide the basis for a more promising approach to develop a Rev-RRE binding inhibitor against HIV-I infection, it is necessary to understand the binding modes of the aminoglycoside antibiotics to RRE. In the present study, the binding mode of a modified antibiotic, a neamine conjugated with pyrene and arginine (NCPA), to RRE has been studied by the methods of $T_m$ measurement and spectroscopic analysis of RRE with or without antibiotics. The results confirmed that NCPA competes with Rev in binding to RRE.

• 한국동물위생학회지
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• 제30권1호
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• pp.1-12
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• 2007

A liquid chromatographic method has been developed for the analysis of aminoglycoside antibiotics (AMGs) using Heptafluorobutyric acid (HFBA) as a ion-pairing reagent. AMGs (amikacin, apramycin, dihydrostreptomycin, gentamicin, hygrosin B, kanamycin, neomycin, spectinomycin and tobramycin) were formed by reaction with HFBA as ion-pairing reagent. HFBA was attached to corresponding amino group of AMGs. These AMGs compounds were separated and detected by electrospray ionization mass spectrometry (ESI-MS). The experimental conditions for separation of AMGs were optimized and validated. A simple liquid chromatographic method for the determination of AMGs was demonstrated.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.384-389
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• 1995

Streptoalloteichus hindustanus ATCC 31219, a nebramycin complex producer, is similar to Streptomyeces tenebrarius in a viewpoint of resistance to a wide range of aminoglycoside antibiotics. S. tenebrarius has resistance mechanisms of 16s rRNA methylation and aminogycoside modification. However, it is not known whether resistance mechanisms of Stall. hindustanus are the same as in S. tenebrarius. Therefore, we have tried to isolate resistance determinants from Stall. hindustanus. Two different types of aminoglycoside resistance determinants were isolated from Stall. hindustanus and expressed in Streptomyces lividans TK24. The apramycin resistance gene (amr) and the tobramycin resistance gene (tmr) isolated from Stall. hindustanus showed broad resistance spectrum against a dozen of aminoglycoside antibiotics. The complete nucleotide sequences of apramycin resistance gene (amr) were determined. The deduced amino acid sequence of the amr gene of Stall hindustanus ATCC 31219 showed extensive sequence homology to the 16s rRNA methylase gene (kamB) of S. tenebrarius.

• Clinical and Experimental Pediatrics
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• 제51권10호
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• pp.1038-1041
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• 2008

Aminoglycosides are frequently used antibiotics in children. The multiple daily dosing (MDD) in infants and children is twice or three times daily depending on age. Recent studies in adults have shown that once daily dosing (ODD) maximizes the bactericidal activity and might minimize the toxicity of antibiotics. So, I reviewed many studies about efficacy, toxicity and cost effectiveness of ODD of aminoglycosides in children. Most studies suggest that ODD compared with MDD of aminoglycosides is theoretically more efficacious and has no higher toxicity in infants and children. But, the total number of patients included in the studies is not large. Multi-center, controlled prospective studies are required in larger numbers of infants and children to determine the efficacy and safety of the ODD regimen in children before ODD of aminoglycosides can be recommended for routine use.

• Journal of Plant Biotechnology
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• 제6권1호
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• pp.25-37
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• 2004

Successful genetic transformation of plants requires non-chimeric selection of transformed tissues and their subsequent regeneration. With rare exceptions, most transformation protocols still rely heavily on antibiotics for selecting transgenic cells that contain an antibiotic-degrading selectable marker gene. Here, the morphogenic capacity of in-vitro explants of chrysanthemnum and tobacco stems and leaves (control and transgenic) changed with the addition of aminoglycoside antibiotics (AAs), In a test of 6 AAs, phytotoxicity occurred at concentrations of 10 to 25 and 50 to 100$\mu\textrm{g}$ $mL^{-1}$ in chrysanthemum and tobacco explants, respectively. Light conditions as well as explant source and size also had significant effects. The use of transverse thin cell layers (tTCLs), in conjunction with high initial AA selection levels, supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow-cytometric analyses revealed no endodu-plication in chrysanthemum, even at high AA levels. However, this phenomenon was observed in tobacco calli(8C or more), even at low AA concentrations (i.e., 5 to 10 $\mu\textrm{g}$ mL$^{-1}$ ).

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.372-379
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• 1991

E.coli ATCC 21990의 aminoglycoside-3'-phosphotransferase(APH(3'))의 신속하고 간편한 정량적 방법을 TLC densitometry를 이용하여 확립하였다. APH(3') 반응생산물인 3' 위치에 인산화된 kanamycin B(3'PKMB)는 silica gel plate에서 cnloroform-methanol-method-ammonia water (3:4:3) 전개용매로 반응물에서 분리되었고, 3'PKMB의 양은 ninhydrin으로 발색 후 densitometry로 측정하였다. APH(3')의 densitometric TLC assay는 좋은 정량적 결과와 재현성을 보였고, 3'-PKMB에 대한 감도는 1.56nmol이었으며 많은 시료의 분석이 한번의 실시로 가능하였다. 이 방법은 aminoglycoside 항생제의 불활화 효소 분석에 응용이 가능하리라 여겨진다.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1529-1535
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• 2013

Tuberculosis is a worldwide epidemic disease caused by Mycobacterium tuberculosis, with an estimated one-third of the human population currently affected. Treatment of this disease with aminoglycoside antibiotics has become less effective owing to antibiotic resistance. Recent determination of the crystal structure of the M. tuberculosis Rv3168 protein suggests a structure similar to that of Enterococcus faecalis APH(3')-IIIa, and that this protein may be an aminoglycoside phosphotransferase. To determine whether Rv3168 confers antibiotic resistance against kanamycin, we performed dose-response antibiotic resistance experiments using kanamycin. Expression of the Rv3168 protein in Escherichia coli conferred antibiotic resistance against $100{\mu}M$ kanamycin, a concentration that effected cell growth arrest in the parental E. coli strain and an E. coli strain expressing the $Rv3168^{D249A}$ mutant, in which the catalytic Asp249 residue was mutated to alanine. Furthermore, we detected phosphotransferase activity of Rv3168 against kanamycin as a substrate. Moreover, docking simulation of kanamycin into the Rv3168 structure suggests that kanamycin fits well into the substrate binding pocket of the protein, and that the phosphorylation-hydroxyl-group of kanamycin was located at a position similar to that in E. faecalis APH(3')-IIIa. On the basis of these results, we suggest that the Rv3168 mediates kanamycin resistance in M. tuberculosis, likely through phosphotransferase targeting of kanamycin.

• Bulletin of the Korean Chemical Society
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• 제24권2호
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• pp.163-164
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• 2003