• 한국동물위생학회지
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• 제40권1호
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• pp.27-33
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• 2017

Salmonella enterica subsp. enterica is a common microbial flora in pet turtles, which could opportunistically become pathogenic to human. Their possession of aminoglycoside resistance genes has important significance both in humans and animal medicine. In this study, twenty-one Salmonella enterica subsp. enterica were isolated from thirty-five individual turtles purchased from pet shops and online markets in Korea. In order to characterize the aminoglycoside susceptibility patterns, antimicrobial susceptibility tests were performed against gentamicin, amikacin and kanamycin of aminoglycoside antimicrobial group. Each of the isolates showed susceptibility to all tested aminoglycosides in disk diffusion and minimum inhibitory concentration (MIC) tests. PCR assay was carried out to determine aminoglycoside resistance genes, integron and integron mediated aminoglycoside genes. None of the isolates showed aac(3)-IIa, aac-(6')-Ib, armA, aphAI-IAB aminoglycoside resistance genes. Only, five isolates (24%) harbored class 1 integron related IntI1 integrase gene. The results suggest that Salmonella enterica subsp. enterica strains isolated from pet turtles are less resistance to aminoglycosides and don't harbor any aminoglycosides resistance genes.

• 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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• 제12권1호
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• pp.18-24
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• 2002

The present study was performed to investigate the excellent microbial anticaries substance, aminoglycoside antibiotic, which is more effective than chlorhexidine for the treatment of dental caries. The aminoglycoside antibiotic against Streptococcus mutans JC-2 from a novel alkaliphilic Bacillus alkalophilshaggy JY-827 exhibited no significant difference at the treatment concentration of $2.5{\times}10^{-7}M$, however, it inhibited the activity of the Streptococcus mutans glucosyltransferase by 70.2% and 99.8% at the concentrations of $2.5{\times}10^{-7}$M\;and\;2.5{\times}10^{-6}M$, respectively. Lineweaver-Burk plot of the inhibitory aminoglycoside antibiotic showed competitive inhibition, with $K_i$ value of $6.4{\times}10^{-6}$ M. The aminoglycoside antibiotic did not show any cytotoxicity against human gingival cells. To evaluate the industrial applicability of the aminoglycoside antibiotic, a toothpaste containing this substance was prepared and tested on the extracted human teeth. The inhibitory rate of tooth calcification and calcium ion elution by the aminoglycoside antibiotic were 50% and 2.5 times, respectively. These results suggested that the aminoglycoside antibiotic from Bacillus alkalophilshaggy JY-827 is an effective agent against dental caries.

• 대한임상검사과학회지
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• 제52권2호
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• pp.136-142
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• 2020

세균의 항균제 내성율은 지난 몇십년 동안 지속적으로 상승하였으며 mobile genetic elements를 통한 항균제내성인자들의 전파는 다제내성세균의 출현 및 확산을 가중시켰다. 본연구에서는 임상검체에서 분리된 aminoglycoside에 비감수성 대장균 33주를 대상으로 mobile genetic elements를 통해 전파될 수 있는 aminoglycoside 내성인자를 조사하였다. 16S ribosomal RNA methyltransferases (RMTases)와 aminoglycoside-modifying enzyme (AME)유전자가 PCR과 DNA 염기서열분석을 통해 검출되었다. 그 결과 aac(3')-II 유전자(54.5%)를 포함하고 있는 균주가 제일 많았으며 그 다음으로 aph(3')-Ia 유전자(18.2%)가 많았고 aac(6')-Ib 유전자(15.2%)를 포함하는 균주도 있었다. RMTase 유전자는 본 연구에서는 검출되지 않았다. aac(3')-II 유전자를 포함하고 있는 18균주 중 17균주가 gentamicin에 내성을 보였으며 이중 16균주는 tobramycin에도 내성을 보였다. aac(6')-Ib 유전자를 포함하고 있는 5균주는 모두 tobramycin에 내성을 보였다. 본 연구에서 AME 유전자를 획득하는 것은 사람에서 분리된 대장균이 aminoglycoside에 내성을 나타내는 중요한 기전 중 하나임이 확인되었다. 사람으로부터 분리된 세균을 대상으로 지속적으로 항균제 내성인자를 조사하는 것은 내성세균의 확산을 막는데 필요할 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.828-831
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• 2003

Although most of the DOS containing aminoglycosides are produced by Streptomyces, very little information is available about their biosynthesis. In the present paper, we report a method to isolate DOI synthase, a key enzyme in the biosynthesis of DOS, from aminoglycoside producer Streptomyces. PCR primers based on conserved region of DOI synthases were specific and reliable for the isolation of the biosynthetic genes of DOS containing aminoglycosides or the screening of the aminoglycoside producers. The use of DOI synthase as a probe could save both time and cost of cloning aminoglycoside biosynthetic genes.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.491-496
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• 1991

Aminoglycoside-3'-phosphotransferase(APH(3'))를 생산하는 균주인 E.coli ATCC 21990을 산업적으로 이용하기 위해서 자외선 조사 및 NTG를 처리하고 고농도의 kanamycin B에 내성을 갖는 변이주인 E.coli M1과 M2를 선별하였다. E.coli M1은 단위 균체당 효소 생산성은 높으나 생육속도가 낮아 실용적이질 못했고 주 질소원인 yeast extract를 사용했을때 E.coli M1보다 E.coli M2가 생육속도가 훨씬 빨랐으며 약 2배의 APH(3')을 얻을 수 있었고 산소 가스를 사용하였을 경우는 약 2.5배의 APH(3')을 얻었다.

• 한국자기공명학회논문지
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• 제6권1호
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• pp.69-77
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• 2002

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

• 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.

• 대한미생물학회지
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• 제21권3호
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• pp.375-380
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• 1986

Thirty-one strains of Pseudomonas aeruginosa were submitted to the synergistic activity test of amikacin(AK) and gentamicin(GM) combined with moxalactam(MX), ceftizoxime(CTZ) or cefoperazone(CFZ). The minimal inhibitory concentrations(MICs) of each drug and drugs combined in various ratios were measured by checkerboard dilution method. The synergism was determined through analysing the MIC distribution curve on isobologram and calculating the fractional inhibitory concentration index(FICI). MICs of GM, AK, MX, CFZ and CTZ against the 31 tested strains were distributed from $12.5{\mu}g/ml$ to $800{\mu}g/ml$, from $0.8{\mu}g/ml$ to $25{\mu}g/ml$, from $3.1{\mu}g/ml$ to $50{\mu}g/ml$, from $3.1{\mu}g/ml$ to $400{\mu}g/ml$, and from $12.5{\mu}g/ml$ to $100{\mu}g/ml$, respectively. The rate synergism of each drug combination by means of FICl was 45.5% in GM-MX, 36.4% in GM-CFZ, 63.6% in GM-CTZ, 48.6% in AK-MX, 35.3% in AK-CFZ, and 35.7% in AK-CTZ combination. Thus, it is suggested that Pseudomonas aeruginosa may effectively be inhibited by various aminoglycoside and cephalosporin combinations.

• 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.