• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.54-65
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• 2002

Black-pigmented bacteria have been implicated in the endodontic infections. This group of microorganisms includes Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens. The organisms display a wide variety of virulence factors that may be pertinent to acute endodontic infections. The aim of this study was to identify P. endodontalis, P. gingivalis, P. intermedia, and P. nigrescens by using special potency disk test, filter paper spot test, 165 rRNA gene-directed PCR, and API 32A. Microbial samples were collected from root canals of 33 intact teeth with necrotic pulp and/or apical periodontitis. Conventional laboratory methods were used for identification of the strains of black pigmented bacteria. Eighteen of 33 samples were positive for the growth of black-pigmented bacteria Five colonies were cultured from each pure cultured colonies from Brucella agar plate. Seventy seven colonies were positive for the growth of black-pigmented bacteria. Thirty three of 77(42.6%) were identifed as P. nigrescens, 10 of 77(12.9%)were P. gingivalis, 6 of 77(7.8%) were P. endodontalis, 10 of 77(12.9%) were P. intermedia. On the contrary the reference strains of P. nigrescens, experimental strains of P nigrescens was sensitive to kanamycin in special potency disk test. 165 rRNA gene PCR and API test after rapid presumptative identification methods, such as special potency disk test and filter paper spot test, would be accurate detection methods for black-pigemented bacteria.

• 생명과학회지
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• 제15권6호
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• pp.879-883
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• 2005

한국산과 중국산 피조개의 신속 진단, 유전적 특성 및 유연관계를 분석하기 위하여 DNA 수준에서 확인 할 수 있는 PCR-aided RFLP를 사용하였다. 피조개 mtDNA 165 rDNA gene를 제한효소로 처리하여 그 band 양상을 조사하고자 하였다. 165 rDNA gene을 분리하기 위하여 ArkF-3, ArkR-3 primer를 사용한 결과 한국산과 중국산 피조개 모두 분자량이 720 bp band가 나타났다 PCR에 의하여 증폭된 16S rRNA gene을 총 8종류의 제한효소(PvuII, BamHI, HinfI, HaeIII, EcoRI, RsaI, Ksp221, BstX21)로 절단하여 RFLP 양상을 보았다. HinfI의 제한효소 처리 시 득량, 가막, 남해, 진해, 태안산 피조개 모두 275 band절편이 관찰되었으나, 중국산은 나타나지 않았다. HinfI를 제외한 나머지 제한효소는 다형형이 관찰되지 않았고 한국산과 중국산 모두 700 bp의 동일한 band를 보였다. HaeIII에서도 득량, 가막, 태안과 남해와 진해산 PCR product가 700 bp위치에서 상이하게 보였다. 또한 한국산과 중국산 절편이 다르게 나타났다. 한국산 피조개 종내 restriction 쇼pe에 의해 유연관계의 결과에 의하면 득량, 가막, 태안은 동일한 유사도를 보였고, 남해와 진해와는 거리가 7 정도로 나타났다. 특히 한국산과 중국산 거리는 25로 나타났다. 이상의 결과를 보아서,HinfI 제한효소는 한국산과 중국산을 구별하는데 매우 유용한 molecular marker가 될 수 있을 것으로 판단되며, 유전적으로 거리가 먼 것으로 보인다. 또한 HaeIII은 한국산 종내 구분 및 중국산 신속 동정에 좋은 molecular tool로 사용될 것으로 예상된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.152-157
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• 2003

Diesel-contaminated soils were ozonated for different times (0 - 900 min) and incubated for 9 wk to monitor petroleum hydrocarbons (PH)-degradative potential of indigenous microorganisms in the soils. Increased ozonation time decreased not only concentration of PH but also number of microorganisms in the soils. Microorganisms in the ozonated soils increased during 9-wk incubation as monitored by culture- and nonculture-based methods. Higher (1-2 orders of magnitude) cell number was observed by quantitative analysis of soil DNA using probes detecting genes encoding 165 rRNA(rrn), naphthalene dioxygenase (nahA), toluene dioxygenase (todC), and alkane hydroxylase (alkB) than microbial abundance estimated by culture-based methods. Such PH-degraders were relatively a few or under detection limit in 900-min ozonated soil. Further PH-removal observed during the incubation period supported the presence of PH-degraders in ozonated soils. Highest reduction (25.4%) of total PH (TPH) was observed in 180-min ozonated soil white negligible reduction was shown in 900-min ozonated soil during the period, resulting in lowest TPH-concentration in 180-min ozonated soil among the ozonated soils. Microbial community composition in 9-wk incubated soils revealed slight difference between 900-min ozonated and unozonated soils as analyzed by whole cell hybridization using group-specific rRNA-targeted oligonucleotides. Results of this study suggest that appropriate ozonation and subsequent biodegradation by indigenous microorganisms may be a cost-effective and successful remediation strategy for PH-contaminated soils.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.423-429
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• 2016

Cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. The main objectives of this study were to detect and identify Cryptosporidium species in captive snakes from exotic pet shops and snake farms in Thailand. In total, 165 fecal samples were examined from 8 snake species, boa constrictor (Boa constrictor constrictor), corn snake (Elaphe guttata), ball python (Python regius), milk snake (Lampropeltis triangulum), king snake (Lampropeltis getula), rock python (Python sebae), rainbow boa (Epicrates cenchria), and carpet python (Morelia spilota). Cryptosporidium oocysts were examined using the dimethyl sulfoxide (DMSO)-modified acid-fast staining and a molecular method based on nested-PCR, PCR-RFLP analysis, and sequencing amplification of the SSU rRNA gene. DMSO-modified acid-fast staining revealed the presence of Cryptosporidium oocysts in 12 out of 165 (7.3%) samples, whereas PCR produced positive results in 40 (24.2%) samples. Molecular characterization indicated the presence of Cryptosporidium parvum (mouse genotype) as the most common species in 24 samples (60%) from 5 species of snake followed by Cryptosporidium serpentis in 9 samples (22.5%) from 2 species of snake and Cryptosporidium muris in 3 samples (7.5%) from P. regius.

• 한국양식학회지
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• 제19권1호
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• pp.40-46
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• 2006

Bacillus subtilis strain with highly active chitosanase was isolated from the intestine of Sebastiscus marmoratus (scorpion fish). It was named as Bacillus subtilis CH1 by morphological, biochemical and 165 rRNA gene analysis. The optimal conditions for chitosanase production were investigated. The optimum carbon and nitrogen sources for Bacillus stibtilis CH1 were 2% starch and 1% yeast extract respectively. Unlike other chitosanases, the expression of this chitosanase was not induced or slightly induced with chitosan. The chitosanase secreted into the medium were concentrated with ammonium sulfate precipitation and purified by gel permeation chromatography. The molecular weight of purified chitosanase was 30 kDa. The optimum pH and temperature of purified chitosanase were 5.5 and $60^{\circ}C$ respectively. The purified chitosanase was continuously thermostable at $40^{\circ}C$ and showed stable activity between pH 6.0 and 8.0. Chitosanase activity of Bacillus subtilis CH1 under optimum condition was 4.1 units/ml.

• 농약과학회지
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• 제16권4호
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• pp.383-386
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• 2012

비농경지의 식물 근권토양에서 식물체의 초기생육촉진 효과가 있는 방선균을 분리하였다. 분리된 미생물의 16S rDNA 염기서열을 분석한 결과 Streptomyces spp.로 동정되었다. Streptomyces griseus (MSS181), Streptomyces griseoaurantiacus (MSS269), Streptomyces microflavus (MSS275), Streptomyces herbaricolor (MSS276)의 배양액을 오이, 고추, 담배와 토마토의 생육초기단계에 관주 처리하여 식물체의 초장, 건조중량을 측정하였다. 방선균 처리에 의해 오이의 초장은 대조구에 비해 16-29% 증가하였으나 건조중량에는 통계적으로 유의한 차이가 없었다. 같은 방선균을 고추에 처리하였을 때 고추의 초장은 대조구에 비해 10-19%, 건조중량은 19-25% 증가하였다. 담배의 건조중량은 44-73% 증가하였고 토마토의 건조중량도 65-165% 증가하였다. 공시균주의 식물병원균에 대한 항균활성을 검정한 결과, MSS275의 Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani와 Sclerotinia sclerotiorum에 대한 강한 항균활성을 확인하였다.

• 미생물학회지
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• 제40권1호
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• pp.1-6
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• 2004

대구지역에서 수집한 50점의 김치 중에서 10점의 김치로부터 tetracycline내성 세균을 분리하였다. 이 균주들의 tetracycline에 대한 MIC는 25-100 mg/l 이상의 범위로 분포하였으며 다른 항생제에 대한 내성도 다양하였다. tet(M), tet(O)특이적 primer를 이용한 PCR에서 HJ9 한 균주에서만 tet(M)유전자가 검출되었으며, tet(M)은 플라스미드상에 존재하는 것으로 나타났다. HJ9 균주의 tet(M)부분 염기서열을 분석한 결과 기존에 보고된 Gram양성균의 tet(M)의 DNA 염기서열 및 아미노산 서열과 각각 90-99%, 94-100%의 높은 상동성을 보였다. 165 rRNA 염기서열을 분석한 결과 HJ9 균주는 Lactobacillus sakei로 동정되었다. 김치를 통하여서도 항생제 내성 유전자의 전파 확산이 가능할 것으로 생각된다.

• BMB Reports
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• 제50권11호
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• pp.578-583
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• 2017

Programmed cell death-1 (PD-1) is a coinhibitory molecule and plays a pivotal role in immune regulation. Here, we demonstrate a role for PD-1 in pathogenesis of inflammatory bowel disease (IBD). Wild-type (WT) mice had severe wasting disease during experimentally induced colitis, while mice deficient for PD-1 ($PD-1^{-/-}$) did not develop colon inflammation. Interestingly, $PD-1^{-/-}$ mice cohoused with WT mice became susceptible to colitis, suggesting that resistance of $PD-1^{-/-}$ mice to colitis is dependent on their gut microbiota. 16S rRNA gene-pyrosequencing analysis showed that $PD-1^{-/-}$ mice had altered composition of gut microbiota with significant reduction in Rikenellaceae family. These altered colon bacteria of $PD-1^{-/-}$ mice induced less amount of inflammatory mediators from colon epithelial cells, including interleukin (IL)-6, and inflammatory chemokines. Taken together, our study indicates that PD-1 expression is involved in the resistance to experimental colitis through altered bacterial communities of colon.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.385-393
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• 2003

Microbial communities were analyzed in an anaerobic/aerobic sequencing batch reactor (SBR) fed with glucose as a sole carbon source. Scanning electron microscopy (SEM) showed that tetrad or cuboidal packet bacteria dominated the microbial sludge. Quinone, slot hybridization, and 165 rRNA gene sequencing analyses showed that the Proteobacteria beta subclass and the Actinobacteria group were the main microbial species in the SBR sludge. However, according to transmission electron microscopy (TEM), the packet bacteria did not contain polyphosphate granules or glycogen inclusions, but only separate coccus-shaped bacteria contained these, suggesting that coccus-shaped bacteria accumulated polyphosphate directly and the packet bacteria played other role in the enhanced biological phosphorus removal (EBPR). Based on previous reports, the Actinobacteria group and the Proteobacteria beta subclass were very likely responsible for acid formation and polyphosphate accumulation, respectively, and their cooperation achieved the EBPR in the SBR operation which was supplied with glucose.

• 식물병연구
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• 제15권3호
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• pp.165-169
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• 2009

남양주와 안성의 GM 고추 격리포장에서 모자이크 병징이 뚜렷한 이병주들로부터 바이러스를 채집하여 그 특성을 조사하였다. CMV RNA3의 외피단백질 유전자를 포함하는 3' 말단 부분에 대한 특이 프라이머를 이용하여 RT-PCR을 실시한 결과, 예상되었던 약 950 bp의 밴드가 확인되었다. 이 PCR 산물을 이용하여 클로닝을 실시하였으며 분석된 외피단백질유전자 염기서열을 토대로 기존에 알려진 Fny-CMV 외피단백질유전자 염기서열과 비교하였다. 남양주와 안성에서 채집된 각 분리주들은 Fny-CMV 염기서열과의 상동성에 있어 특별한 차이를 보이지 않았지만 염기서열을 이용한 계통발생분석에서는 두 지역간 CMV가 확연히 다른 그룹으로 나타났다. 한편, 분리된 각 CMV의 외피단백질유전자 염기서열을 통해 확인된 아미노산서열과 Fny-CMV의 외피단백질 아미노산 서열을 비교한 결과, 남양주에서 분리된 CMV가 96.8%에서 97.3%의 유사성을 보인 반면, 안성의 고추포장에서 분리된 CMV는 95.9%에서 96.8%의 유사성을 보였다. 특히 남양주에서 분리된 CMV와 Fny-CMV 모두 88번째 잔기에서 Lysine(K)을 포함하지만 안성에서 분리된 CMV는 Arginine(R)을 포함하였으며, 91번째 잔기에서 전자는 Leucine(L)을 포함하지만 후자는 Valine(V)을 포함하는 것이 확인되었다. 이 같은 결과를 종합해볼 때, 남양주와 안성의 고추에서 각각 분리된 CMV는 서로 다른 지역적 특색을 나타내는 것으로 확인되었다.