• 한국어병학회지
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• 제26권3호
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• pp.185-191
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• 2013

본 연구는 E. tarda에 대한 특이박테리오phage와 생균제의 일종인 B. subtilis KM-1의 혼합제가 E. tarda에 대한 항균활성에 미치는 효과를 알아보고자 수행되었다. 가장 효과적인 혼합제의 항균활성을 보인 phage의 적정 수는 B. subtilis 가 $2{\times}10^5$ CFU/ml의 농도로 존재할 때 배양 36시간째 $2{\times}10^5$ PFU/ml로 나타났다. B. subtilis의 경우 $2{\times}10^5$ PFU/ml의 phage가 존재할 때 첨가량에 비례하는 항균활성을 보여주었다. phage와 B. subtilis의 혼합투여는 phage나 B. subtilis 각각을 투여한 그룹보다 훨씬 높은 항균활성을 나타냈다. 본 연구의 결과는 수산양식에서 대두되고 있는 양식어류의 E. tarda 감염성 질병 치료를 위한 항생제 대체제로서의 사료첨가제 개발 가능성을 제시하고 있다.

• 자연과학논문집
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• 제9권1호
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• pp.19-24
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• 1997

PCR 방법을 이용하여 K11 RNA 중합효소를 coding하는 Klebsiella phage gene 1을 cloning 하였고 lac 전사촉진제 조절 하에 발현시켰다. K11 RNA 중합효소는 DAEA-sephacel과 Affigel blue column chromatographies를 사용하는 상용 방법으로 분리하였다. DAEA-sephacel의 0.2-0.3 M $NH_4Cl$ 분획에서 K11 RNA 중합효소의 활성을 보였고, 다음 단계의 Affigel blue column에서 SDS-polyacryl amide gel 상의 단일 band로 분리되었다. K11 RNA 중합효소는 T7 그룹 phage RNA 중합효소로 다른 T7 그룹phage RNA 중합효소와 많은 상동성을 보인다. (대장균 phage T7, T3과 Salmonella tyhimurium phage SP6 RNA 중합효소). 이미 우리는 T7과 SP6 전사촉진제 변이체를 제조한 바 있고 T7과 SP6 RNA 중합효소의 전사촉진제 특이성을 연구한 바 있다 (이상수와 강창원, 1993). K11 RNA 중합효소의 전사촉진제 특이성을 알아보기 위해 SP6 전사촉진제 변이체를 사용하여 in vitro K11 RNA 중합효소의 활성을 측정하였다. 이 변이체 중 K11 전사촉진제와 가장 유사한 것이 가장 높은 K11 RNA 중합효소 활성을 보였다.

• 한국어병학회지
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• 제11권2호
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• pp.137-141
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• 1998

TSB 해수배지와 숙주로서 L. garvieae No. 44를 배양조건으로 사용한 경우, L. garvieae 111균주중 용원화되었다고 추정되어진 96균주의 cells에서 temperate Phage가 효과적으로 분리되었다. 하지만 동일한 배양조건에서 보통의 TSB 배지를 사용한 경우에서는 temperate phage는 전혀 나타나지 않았다. 이 temperate phages는 TSB 해수배지와 ultraviolet irradiation를 병용한 경우 역시 효과적으로 분리되었다. 분리된 모든 temperate Phages는 기존의 phage(PLgY, PLgW, PLgS) 의 lytic nature와는 달리 오직 L.garvieae No. 44만을 lysis하였다. 배양후 약 1시간후 phage가 나타났으며 12시간 후 virulent phage의 최고농도($10^{10}$ PFU/ml) 보다 훨씬 낮은 농도인 $10^6$ PFU/ml까지 증가하였다.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.935-941
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• 2010

The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. Bacteriophages have been suggested as an alternative therapeutic agent for such bacterial infections. In the present study, we examined the therapeutic potential of phage Kpn5 in the treatment of Klebsiella pneumoniae B5055-induced burn wound infection in a mouse model. An experimental model of contact burn wound infection was established in mice employing K. pneumoniae B5055 to assess the efficacy of phage Kpn5 in vivo. Survival and stability of phage Kpn5 were evaluated in mice and the maximum phage count in various organs was obtained at 6 h and persisted until 36 h. The Kpn5 phage was found to be effective in the treatment of Klebsiella-induced burn wound infection in mice when phage was administered immediately after bacterial challange. Even when treatment was delayed up to 18 h post infection, when all animals were moribund, approximately 26.66% of the mice could be rescued by a single injection of this phage preparation. The ability of this phage to protect bacteremic mice was demonstrated to be due to the functional capabilities of the phage and not due to a nonspecific immune effect. The levels of pro-inflammatory cytokines (IL-$1{\beta}$ and TNF-${\alpha}$) and anti-inflammatory cytokines (IL-10) were significantly lower in sera and lungs of phage-treated mice than phage untreated control mice. The results of the present study bring out the potential of bacteriophage therapy as an alternate preventive approach to treat K. pneumoniae B5055-induced burn wound infections. This approach not only helps in the clearance of bacteria from the host but also protects against the ensuing inflammatory damage due to the exaggerated response seen in any infectious process.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1518-1522
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• 2006

In the present study, it was observed how the phage-host system that is naturally reproduced in activated sludge is affected by the host inoculation. The system of Microlunatus phosphovorus and its phages was selected as the phage-host system native to an activated sludge system operated for 19 days under sequencing anaerobic-aerobic conditions with glutamate as the main carbon source. The phage-host system related to M. phosphovorus was monitored by plaque assay for the phages and by fluorescent in situ hybridization (FISH) for the bacterial host. In addition, the whole phage structure was also monitored by pulsed-field gel electrophoresis (PFGE). During the first 9 days, the phage-host system was more or less steady at approx. 9% (FISH/ DAPI) for M. phosphovorus and approx. 10,000 PFU/ml for its lytic phages. Microlunatus phosphovorus JCM9379 was inoculated into the activated sludge on day 10. Right after the inoculation, M. phosphovorus was approx. 24% (FISH/DAPI) whereas its lytic phages dropped down to approx. 500 PFU/ ml. After the host inoculation (within 9 days), however, the phage-host system eventually reverted to its original level in each population. On the other hand, the whole phage structure was not significantly changed by M. phosphovorus inoculation but stable throughout the process operation. Only the minor change that four phage groups gradually became abundant after the host inoculation was observed.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1613-1620
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• 2012

Bacterial wilt caused by Ralstonia solanacearum is a devastating disease of many economically important crops. Since there is no promising control strategy for bacterial wilt, phage therapy could be adopted using virulent phages. We used phage PE204 as a model lytic bacteriophage to investigate its biocontrol potential for bacterial wilt on tomato plants. The phage PE204 has a short-tailed icosahedral structure and double-stranded DNA genome similar to that of the members of Podoviridae. PE204 is stable under a wide range of temperature and pH, and is also stable in the presence of the surfactant Silwet L-77. An artificial soil microcosm (ASM) to study phage stability in soil was adopted to investigate phage viability under a controlled system. Whereas phage showed less stability under elevated temperature in the ASM, the presence of host bacteria helped to maintain a stable phage population. Simultaneous treatment of phage PE204 at $10^8$ PFU/ml with R. solanacearum on tomato rhizosphere completely inhibited bacterial wilt occurrence, and amendment of Silwet L-77 at 0.1% to the phage suspension did not impair the disease control activity of PE204. The biocontrol activities of phage PE204 application onto tomato rhizosphere before or after R. solanacearum inoculation were also investigated. Whereas pretreatment with the phage was not effective in the control of bacterial wilt, post-treatment of PE204 delayed bacterial wilt development. Our results suggested that appropriate application of lytic phages to the plant root system with a surfactant such as Silwet L-77 could be used to control the bacterial wilt of crops.

• 한국식품위생안전성학회지
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• 제35권6호
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• pp.602-606
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• 2020

본 연구는 다양한 항생제 내성을 갖는 Salmonella enterica subsp. enterica serovar Typhimurium ATCC 19585 (STWT), S. Typhimurium KCCM 40253 (STKCCM), ciprofloxacininduced S. Typhimurium ATCC 19585 strains (STCIP), and S. Typhimurium CCARM 8009 (STCCARM)에 대한 phage의 흡착 및 용균 특성을 평가하였다. PBST-10, PBST-13, PBST-32, PBST-35, P-22, P-22 B1 phages는 narrow host range를 보였다. 숙주인 STWT, STKCCM, STCIP에 대한 phage의 흡착률은 각각 47-85%, 58-95%, 61-93%였지만, STCCARM에 대한 phage의 흡착률은 14-36%의 낮은 수준을 보였다. STWT, STKCCM, STCIP, STCCARM에 대한 phage burst size는 각각 43-350, 37-530, 66-500, 24-500 plaque-forming unit(PFU)으로 다양하게 관찰되었다. P-22 B1을 제외한 모든 phage는 배양 초기에 STCIP숙주를 효과적으로 저해하였다. 이러한 결과는 항생제 내성균을 저해하기 위해 phage control system 개발에 유용한 정보로 활용될 것이다.

• Applied Microscopy
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• 제12권1호
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• pp.33-40
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• 1982

Several phages of Bacillus thuringiensis distributed in Korea were isolated. The distribution and morphological characteristics of phages were studied. The results are as follows; 1. The isolated phages were highly specific for Bacillus thuringiensis var. thuringiensis. They were classified as YM series phages and designated as phage YM-1, YM-2 and YM-3 according to their morphological characteristics. 2. Most of these YM series phages were isolated from compost including domestic animal dung and soil under sewage. 3. The YM-1 phage was similar to Bacillus subtilis ${\phi}25$ in morphology. It has 94nm x 86nm head, contractile tail sheath and base plate with four cornered structure. 4. The YM-2 phage was similar to Bacillus subtilis GA-1 phage in morphology. It had 70nm x 56nm head and tail without contractile tail sheath. 5. The YM-3 phage was similar to Bacillus subtilis ${\phi}29$ phage. It had 56nm x 43nm head and tail with distal enlargement.

• Journal of Microbiology
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• 제38권3호
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• pp.176-179
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• 2000

A challenge phage system was used to study the DNA-protein interaction between C4-dicarboxylic acid transport protein D(DCTD) or $\sigma$54, and a $\sigma$54 -dependent promoter, dctAp. R. meliloti dctA promoter regulatory region replaced the Omnt site on the phage. S. typhimurium strains overproducing either DCTD or $\sigma$54 directed this challenge phage towards lysogency, indicating that DCTD or E$\sigma$54 recognized the dctA promoter on the phage and repressed transcription of the ant gene. These challenge phage constructs will be useful for examining interactions between DCTD(or $\sigma$54) and the dctA promoter region.

• 한국축산식품학회지
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• 제37권6호
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• pp.884-888
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• 2017

In this study, we report the morphogenetic analysis and genome sequence of a new WCP30 phage of Weissella cibaria, isolated from a fermented food. Based on its morphology, as observed by transmission electron microscopy, WCP30 phage belongs to the family Siphoviridae. Genomic analysis of WCP30 phage showed that it had a 33,697-bp double-stranded DNA genome with 41.2% G+C content. Bioinformatics analysis of the genome revealed 35 open reading frames. A BLASTN search showed that WCP30 phage had low sequence similarity compared to other phages infecting lactic acid bacteria. This is the first report of the morphological features and complete genome sequence of WCP30 phage, which may be useful for controlling the fermentation of dairy foods.