• Research in Plant Disease
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• v.22 no.1
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• pp.9-17
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• 2016

Nationwide survey for angular leaf spot (ALS) of strawberry caused by Xanthomonas fragariae, a quarantine disease in Korea, was performed in November 2012. In the survey, ALS was observed in eighty eight farmers' fields of Sukok, Jinju and Okjong, Hadong in Gyeongnam Province, and one field in Namwon of Jeollabuk Province. The infected field of Namwon closed immediately after the disease diagnosed ALS. In detailed survey of Sukok and Okjong areas during February 2012 to January 2015, ALS occurrence decreased from 45% farmer's fields on December 2012 to 5% on January 2015, and from 38% on November 2013 to 5% on January 2015, respectively. Phenotypic characteristics of the Korean strains were similar to those of the type strain of X. fragariae. A multilocus sequence analysis of Korean strains of X. fragariae was conducted using four genes; dnaK, fyuA, gyrB, and rpoD. All the Korean strains had the same sequences of the four genes. The concatenated sequences of the Korean strains shared 100% with that of the type strain of X. fragariae. All strawberry cultivars tested were susceptible to the strains of X. fragariae two weeks after inoculation. The inoculated sites were necrosis and expanded, which were rated 4 based on evaluation of inoculation site.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.15-26
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• 2014

The black soldier fly, Hermetia illucens, larvae may depend on indigenous bacteria in the intestine to feed and digest diverse food sources. To prove this hypothesis, we isolated and identified the intestinal bacteria of the black soldier fly for their digestive and antimicrobial abilities. The last instar larvae had long digestive tracts, which were about seven times longer than its body length. An individual of H. illucens larvae possessed a total of $5.0{\pm}10^6$ bacteria in the whole intestine, of which more than 98% bacteria were located in the hindgut. Three different bacterial isolates cultured on nutrient agar (NA) medium were detected in the intestine and identified as Morganella morganii, Providencia rettgeri and Bacillus halodurans by Biolog microbial identification system. Analysis of 16S rDNA sequences of the intestinal bacteria detected the additional bacteria of Proteus mirabilis, Providencia alcalifaciens, and Providencia sp. These intestinal bacteria cultured on NA medium exhibited high resistance to 4 antibiotics and inhibited growth of other microbes which are mainly plant pathogens. Also, these bacteria exhibited catalytic activities to degrade cellulose, lipid, proteins, and carbohydrates. These results suggest that H. illucens larvae possess intestinal bacteria that may play crucial roles in their digestive physiology.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.175-182
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• 2016

In this study, we isolated aromatic compounds (lignin polymers) utilizing bacteria in humus layer of oak forest and investigated phylogenetic characteristics and correlation with major bacterial populations in the humus layer by pyrosequencing. Forty-two isolates using aromatic compounds such as p-anisic acid, benzoic acid, ferulic acid and p-coumaric acid were isolated and phylogentic analyses based on 16S rRNA gene sequences showed that the isolates belonged to the genus Rhizobium, Sphingomonas, Burkhorlderia, and Pseudomonas. Among these, Burkhorlderia species which belong to Betaproteobacteria class occupied 83% among the isolates. The bacterial populations in humus layer of oak forest were characterized by next generation pyrosequencing based on 16S rRNA gene sequences. The humus sample produced 7,862 reads, 1,821 OTUs and 6.76 variability index with 97% of significance level, respectively. Bacterial populations consist of 22 phyla and Betaproteobacteria were the major phylum consisting of 15 genera including Burkholderia, Polaromonas, Ralstoria, Zoogloea, and Variovorax. Approximately fifty percentage of them was Burkholderia. Burkholderia as the majority of population in the humus was considered to play a role in degrading lignin in humus layer of oak forest.

• Research in Plant Disease
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• v.30 no.2
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• pp.165-175
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• 2024

The Korean fir tree (Abies koreana), an endemic species of South Korea, is experiencing a severe decline in population due to climate change. Studies on the conservation of Korean fir have been extensive, yet research regarding its correlation with rhizosphere bacterial communities remains scarce, warranting further investigation. In this study, metagenome amplicon sequencing targeting the 16S rRNA V4 region was conducted to examine the presence of specific bacterial communities in Korean fir and to investigate potential differences based on habitat types (rhizosphere of native or cultivated trees, soil of dead trees, and bulk soil) and seasonal variations (April, June, September, November). Here we show that although we could not identify specific taxa highly specifically with Korean fir, the rhizosphere bacterial community in native trees exhibited less variability in response to seasonal changes compared to that in bulk soils. Suggesting the establishment of relatively stable bacterial populations around the Korean fir natural habitat. Further research on other types of rhizosphere and/or microbes is necessary to investigate the distinct relationship of Korean fir with microbial communities.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1008-1012
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• 2003

Purpose : We aimed to ascertain whether lumbar punctures should be done to prove febrile seizure, and to study what conditions can delay or abolish lumbar puncture. Methods : This retrospective study was done for four years, from January, 1996 to December, 1999. The subjects were the patients who visited Masan Samsung Hospital for the first convulsion with fever, and whose age ranged from 1-month to 5-years old. The total number of patients was 197. We investigated the rate of meningitis, which was classified by age, season, convulsion type, associated symptoms, and results of blood test. All data were tested chi-square. Results : The diagnosis rate of meningitis among all 197 patients was 7.6%, and of these only one patient was proved to have bacterial meningitis. The rate was high in the young(below 6 month), in males and in summer and autumn. Although the general appearance was good after resolution of the fever, the rate of meningitis was 6.5%. Patients with nausea and vomiting totalled 11%; 9.1% of them were diagnosed with meningitis. The diagnosis rate of meningitis in cases in which additional seizures took place were 33.3%. Conclusion : The ultimate goal of lumbar punctures in seizure patients with accompanying fever is to rule out bacterial meningitis, which, has been demonstrated to be rare. So we think that lumbar puncture can be postponed by close observation of pediatrics specialists and skilled nurses.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.183-195
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• 2002

흑색 색소를 형성하는 그람음성 혐기성 세균은 급성 임상 증상을 가진 환자의 근관에서 자주 발견되는 세균으로서 세균 및 세균의 성분과 산물이 치근단 병소의 생성과 밀접하게 연관된 것으로 알려져 있다. 본 연구는 흑색 색소를 형성하는 그람음성 혐기성 세균 중 가장 발현율이 높은 Prevotella nigrescens가 배양된 세포에 미치는 세포 독성을 연구하고자 하였다. 두 가지 세포주 및 사람의 치은섬유모세포를 일차배양하여 사용하였으며, 세포주에 따른 독성 발현에 차이가 있는지를 비교하였다. P. nigrescens ATCC 33563 표준 균주 및 임상 균주로는 환자의 감염된 근관으로부터 165 rRNA primer를 사용한 중합효소 연쇄반응으로 P. nigrescens 6 균주를 동정하여 사용하였다. 세균배양액, 세균의 초음파 추출단백질 및 lipopolysaccharide (LPS)를 MC3T3-El 조골세포, NIH3T3 섬유모세포 및 치은섬유모세포에 첨가한 후 MTT분석법으로 세포의 활성을 측정하였으며, 세포의 형태학적 변화를 도립현미경으로 관찰하였다. 세균배양액을 100$\mu\textrm{l}$ 첨가한 경우는 세가지 세포주 모두에서 통계적으로 유의하게 세포의 활성을 억제하였다. 세균의 초음파 추출단백질 12.5$\mu\textrm{g}$/ml 와 25$\mu\textrm{g}$/ml 는 NIH3T3세포에 통계적으로 유의한 세포독성을 보였다. 세 가지 세포주에 대한 LPS의 세포 독성 효과는 첨가된 LPS의 농도 및 균주에 따라 다양하게 나타났다. 심하게 손상된 세포는 세포의 단일층이 수축되고 세포가 응집되었으며 세포가 배양용기의 바닥에서 떨어지는 양상이 도립 현미경하에서 관찰되었다. 본 연구의 결과 P. nigrescens가 숙주 반응을 조절하여 치수 및 치근단 병소의 유발 및 악화에 기여하는 세균으로 작용할 수 있음을 시사한다. 조직과 함께 제거하고 포르말린에서 48시간 고정시킨 후 파라핀에 포매한 다음에 micro-tome을 사용하여 6$\mu\textrm{m}$로 serial section을 시행하였다. 정중선 부위의 시편에 Hematoxylin-Eosin staining을 시행한 후 Olsson, Orstavik 그리고 Mjor 등의 방법에 따라 조직학적 변화를 관찰한 후 slight(1), moderate(2), severe inflammation(3)의 단계로 분류하였다. 얻어진 결과를 통계처리 프로그램인 Jandel사의 Sigmastat을 이용하여 Kruskal Wallis Test로 통계처리를 하였다. 결과 : (Table omitted) 결론 : 1) Pulp Canal Sealer를 제외한 모든 군에서 시간이 지남에 따라 유의성 있게 염증이 감소되는 양상을 보였다(p<0.05). 2) Pulp Canal Sealer는 1주, 2주, 12주에서 강한 염증반응을 보였다. 3) AH 26과 AH Plus에서는 1주, 2주에서 강한 염증반응을 보였으나 12주에서는 염증반응이 감소하였다. 4) 새로 개발된 봉함제 Adseal-1,2는 1주, 2주에서는 가장 약한 염증반응을 보이나 4주, 12주 후에는 AH Plus와 비슷한 수준의 염증 반응을 보였다. 5) Pulp Canal Sealer를 제외한 모든 군에서 인정할 만한 생체친화성을 보였다. 6) Adseal-2가 Adseal-1에 비하여 전반적으로 낮은 염증반응을 보였다. 7) 각 군간 결과의 차이에 통계적 유의성은 없었다(p>0.05).mmunity. Then, a hierarchical language is to defeat its own purpose.중 행정부가 북한에 대해 실시한 포용정책이 어떠한 성과를 거두고 어떠한 문제점을 간과하고 있는가에 대해 논의하고, 대북 정책의 새로운 지평을 논의하는 것을 목적으로 하고 있다. 1) 포용 정책은 세계의

• Journal of Sericultural and Entomological Science
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• v.32 no.2
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• pp.101-104
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• 1990

The bacteria isolated from mulberry trees which had shoot soft rot symptoms occurred after intermediate cutting during autumn rearing season were indentified. External morphology of the bacteria showed rod shape with peritrichous flagella, and were facultative anaerobes in oxygen requirement test. The baacteria easily putrefied the slices of potato and carrot when they were placed on to the center of sliced surfaces, and the bacteria, also, iniciated rapid development of soft rot symptoms on mulberry leaves in pathogenesity test. The results of morphological, physiological and pathological tests on the bacteria suggested that the isolate could be a strain of Erwinia carotovora subsp. carotovora.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.116-120
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• 1996

Water-soaked spots or lesions were observed on fruits or stems of melon plants at house-melon farms in Andong, Korea. The symptoms developed to soft rot of the fruits of wilting of the whole plants. The causal organism isolated from the water-soaked le-sions was identified as Erwinia carotovora subsp. carotovora based on the morphological and physiological characteristics. The causal bacterium was susceptible to not only two kinds of medical antibiotics but also two kinds of agrochemicals tested. Since the bacterial soft rot is a first described bacterial disease in melon in Korea, we propose to name the disease as "bacterial soft rot of melon".

• Research in Plant Disease
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• v.11 no.2
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• pp.135-139
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• 2005

Bacterial canker of Japanese apricot (Prunus mume Sieb. et Zucc.) was found in all orchards located at southern area of Korea. Typical symptoms were characterized by dark spots formed on fruits, brown lesions on leaves, and bacterial exudate oozed out of the cracked bark of diseased tree. Thirty-eight isolates from 16 different areas were identified on the basis of biochemical and physiological characteristics (LOPAT and GATTa test) and also on the basis of 165 rDNA and ITS sequences. Pathogenicity tests confirmed that bacterial canker of Japanese apricot in Korea is caused by Pseudomonas syringae pv. morsprunorum.

• The Korean Journal of Food And Nutrition
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• v.14 no.3
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• pp.255-262
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• 2001

랩포장 및 진공포장이 냉장 돈육이 저장성에 미치는 영향을 조사하기 위해 돈육의 등심부의를 랩포장 및 진공포장한 후 냉장저장하면서 저장기간에 따른 세균수,휘발성 염기질소, pH, 보수력 드립감량, 가열감량 및 경도의 변화를 측정하였다. 랩포장의 경우 일반세균수는 저장 10일에 2.0$\times$$10^{7}$ CGU/㎤의 수준에 달하였고, 휘발성 염기질소 함량은 저장 15d일에 26mg%로서 식육의 부패수준인 20mg%를 초과하였으며 , pH는 저장 7일 이후 급속하게 증가되어 저장 10일에 5.98의 수준이었다. 반면에 진공포장의 경우에는 일반세균수가 저장 30일에 7.7$\times$$10^{6}$ CGU/㎤의수준에 달하였고, 휘발성 염기질소 함량은 저장 30일에 19.8mg%로서 부패수준인 20mg%에 근접하였으며, pH는 저장기간이 경과됨에 따라 매우 완만하게 증가되어 저장 30일에 pH5.75의 수준이었다. 보수력은 저장 1일에는두 시험구가 75.0%의 수준으로 비슷하였으나, 저장기간이 경과됨에 따라 랩포장이 진공포장에 비해 급속하게 증가되었다. 드립감량과 가열감량은 저장초기인 저장 7일까지는 진공포장이 랩포장에 비해 다소 높은 수준이었으나 그 이후에는 랩 포장이 높은 수준이었다. 경도는 두 시험구 모두 저장 1일에 가장 높았고, 저장 기간이 경과됨에 따라 점차 저하되었으며, 랩포장에 비해 전공포장이 비교적 완만하게 저하되었다.