• 한국응용곤충학회지
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• 제20권4호
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• pp.183-190
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• 1981

작물시험장, 충남농촌진흥원 및 일반농가에서 수집한 40개 참깨종자표본의 종자전염진균을 Blotter 법으로 조사하였던 바 Alternaria sesami, A. sesamicola, A. tenuis, A. longissima, Cercospora sesami, Cephalosporium sp., Corynespora cassiicola, Fusarium equiseti, F. moniliforme, F. oxysporum, F. semitectum, Macrophomina phoseolina 그리고 Myrothecium roridum이 검출되었다. 그 중 A. sesami, A. sesamicola, A. tenuis, C. cassiicola가 많은 비율로 검출되었다. 참깨 종자내의 감염부위를 알아본 결과, C. cassiicola가 가장 깊숙이 배에까지 감염되어 있었으며 Chlorine으로 종자표면소독을 하였을 경우에도 완전히 제거되지 않았다. 이균에 이병된 종자를 살균토양에 파종하였을 경우 심한 발아저해와 유묘고사를 초래하였다. C. cassiicola의 종자상에서의 생육상과 배양기상에서의 배양적성질 및 포자의 형태를 기술하였다. 병원성을 조사하기 위하여 배양균의 포자현탁액을 참깨에 분무접종한 결과, C. cassiicola는 참깨의 잎과 줄기에 또는 자색의 병반을 나타내며 이것이 급격히 확대되어 고사하였다. A. sesami, A. sesamicola, A. longissima, C. sesami도 참깨 잎에 반점 또는 blight의 병징을 나타내었으나, A. tenuis은 병원성이 없었다. 토양접종실험의 결과, F. oxysporum과 M. phaseolina는 강한 병원성을 나타내어 심한 종자부패와 유묘고사를 초래하였다.

• The Plant Pathology Journal
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• 제29권4호
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• pp.440-445
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• 2013

Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be $24^{\circ}C$. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time.

• 한국방사선학회논문지
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• 제14권5호
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• pp.537-543
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• 2020

현대사회의 노인 인구는 첨단 의료기술과 최소 침습 수술로 인해 빠르게 성장하고 있다. 따라서 의료기기를 사용하는 경향이 증가하기 때문에 병원성 감염이 우려된다. 따라서 현대 의학의 최우선 목표는 감염예방이다. 최근 3D 프린팅을 이용하여 환자 맞춤형 임플란트 이식술이 늘고 있다. 대표적 재료로 이용되는 것이 수산화인회석이다. 현재 HA 디스크 멸균을 위한 흡수선량 기준이 없으므로, HA 디스크 표면에 오염된 대장균과 충치균을 감마선 코발트와 선형 가속기를 이용하여 각 흡수선량 0, 0.5, 1.0, 3.0, 5.0 kGy로 조사 후, 십진 희석법으로 검체에서 균 수를 측정하였다. 멸균 후 대장균, 충치균의 생존 비교분석을 위해 비모수 검정법을 시행하였으며, 그 결과 대장균은 1 kGy 이상, 충치균은 3 kGy 이상에서 멸균되었다. 방사선 멸균 흡수선량 권고사항보다 낮은 수치에서 멸균을 시행하는 것도 가능할 것으로 생각된다.

• Mycobiology
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• 제47권4호
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• pp.473-482
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• 2019

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most important diseases in rice production. PAS (period circadian protein, aryl hydrocarbon receptor nuclear translocator protein, single-minded protein) domains are known to be involved in signal transduction pathways, but their functional roles have not been well studied in fungi. In this study, targeted gene deletion was carried out to investigate the functional roles of the PAS-containing gene MoPAS1 (MGG_02665) in M. oryzae. The deletion mutant ΔMopas1 exhibited easily wettable mycelia, reduced conidiation, and defects in appressorium formation and disease development compared to the wild type and complemented transformant. Exogenous cAMP restored appressorium formation in ΔMopas1, but the shape of the restored appressorium was irregular, indicating that MoPAS1 is involved in sensing the hydrophobic surface. To examine the expression and localization of MoPAS1 in M. oryzae during appressorium development and plant infection, we constructed a MoPAS1:GFP fusion construct. MoPAS1:GFP was observed in conidia and germ tubes at 0 and 2 h post-infection (hpi) on hydrophobic cover slips. By 8 hpi, most of the GFP signal was observed in the appressoria. During invasive growth in host cells, MoPAS1:GFP was found to be fully expressed in not only the appressoria but also invasive hyphae, suggesting that MoPAS may contribute to disease development in host cells. These results expand our knowledge of the roles of PAS-containing regulatory genes in the plant-pathogenic fungus M. oryzae.

• The Plant Pathology Journal
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• 제32권4호
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• pp.281-289
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• 2016

The transcription cofactor Swi6 plays important roles in regulating vegetative growth and meiosis in Saccharomyces cerevisiae. Functions of Swi6 ortholog were also characterized in Fusarium graminearum which is one of the devastating plant pathogenic fungi. Here, we report possible role of FgSwi6 in the interaction between F. graminearum and Fusarium graminearum virus 1 (FgV1) strain DK21. FgV1 perturbs biological characteristics of host fungi such as vegetative growth, sporulation, pigmentation, and reduction of the virulence (hypovirulence) of its fungal host. To characterize function(s) of FgSWI6 gene during FgV1 infection, targeted deletion, over-expression, and complementation mutants were generated and further infected successfully with FgV1. Deletion of FgSwi6 led to severe reduction of vegetative growth even aerial mycelia while over-expression did not affect any remarkable alteration of phenotype in virus-free isolates. Virus-infected (VI) FgSWI6 deletion isolate exhibited completely delayed vegetative growth. However, VI FgSWI6 over-expression mutant grew faster than any other VI isolates. To verify whether these different growth patterns in VI isolates, viral RNA quantification was carried out using qRT-PCR. Surprisingly, viral RNA accumulations in VI isolates were similar regardless of introduced mutations. These results provide evidence that FgSWI6 might play important role(s) in FgV1 induced phenotype alteration such as delayed vegetative growth.

• 한국동물위생학회지
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• 제37권3호
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• pp.213-218
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• 2014

In early April 2014, a month-old Alexandrine Paraqeet (Psittacula eupatria) that was raised in a domestic aviary located in Gyungju-si, Korea was suddenly died and submitted to Animal Disease Intervention Center, Kyungpook National University in order to diagnose the causative agent. In post-mortem examination, the bird had abnormally developed feathers on the neck and abdomen region and subcutaneous hemorrhages on the neck and cheek adjacent to the beak. At necropsy, the bird had hemorrhage on the muscle of the femoral region, ascites, multi-focal hemorrhages on the epicardium, and diffuse hemorrhages on the sub-serosa of proventriculus and gizzard, suggesting typical avian polyomavirus (APV) infection. The partial large tumor (T) antigen gene of APV was detected by PCR from tissues of the heart, lung, liver, kidney, proventriculus and feathers of the APV-suspected birds. However, other pathogenic virus-specific nucleic acid common with psittacine birds such as avian bornavirus, psittacine beak and feather disease virus and psittacid herpesvirus were not detected from the mixed tissue samples of the bird, indicating this case is due to single infection of APV. Nucleotide sequence analysis of the partially amplified large T antigen DNA was confirmed to have 99~100% homology with that of the previously reported APV strains. This case report describes the first detection of APV in Alexandrine Paraqeet in Korea.

• 대한미생물학회지
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• 제35권4호
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• pp.317-324
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• 2000

Candida albicans is one of the most frequently isolated fungal pathogens in human. Recently, the prevalence of candida infection has markedly increased, partially due to the increase of immunocompromised hosts. Proposed virulence factors of the pathogenic Candida are the ability to form hyphae to adhere to epithelial cell surfaces, and to secrete acid proteinases and phospholipases. We measured the relative cell surface hydrophobicity (CSH) and the ability of proteinase production (PROT), phospholipase production (PLase), adherence to host epithelium (ADH), and hyphal transition (Germ). The relative risk of virulence factors was analyzed by lethality test in murine model of hematogeneously disseminated candidal infection. According to Cox's proportional hazard analysis, the statistically significant virulence factors were PROT, ADH, and CSH. PROT was the highest risk factor of them. To evaluate the applicability for the diagnosis and treatment of Candidiasis, we examined the protective effect of the active and passive immunizations with the materials purified from virulence factors and antibodies to them in Candia-infected mice model. The mean survival times of active and passive immunized groups were slightly longer than those of non-immunized groups.

• The Plant Pathology Journal
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• 제33권4호
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• pp.370-381
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• 2017

Rathayibacter tritici, which is a Gram positive, plant pathogenic, non-motile, and rod-shaped bacterium, causes spike blight in wheat and barley. For successful pathogenesis, R. tritici is associated with Anguina tritici, a nematode, which produces seed galls (ear cockles) in certain plant varieties and facilitates spread of infection. Despite significant efforts, little research is available on the mechanism of disease or bacteria-nematode association of this bacterium due to lack of genomic information. Here, we report the first complete genome sequence of R. tritici NCPPB 1953 with diverse features of this strain. The whole genome consists of one circular chromosome of 3,354,681 bp with a GC content of 69.48%. A total of 2,979 genes were predicted, comprising 2,866 protein coding genes and 49 RNA genes. The comparative genomic analyses between R. tritici NCPPB 1953 and R. toxicus strains identified 1,052 specific genes in R. tritici NCPPB 1953. Using the BlastKOALA database, we revealed that the flexible genome of R. tritici NCPPB 1953 is highly enriched in 'Environmental Information Processing' system and metabolic processes for diverse substrates. Furthermore, many specific genes of R. tritici NCPPB 1953 are distributed in substrate-binding proteins for extracellular signals including saccharides, lipids, phosphates, amino acids and metallic cations. These data provides clues on rapid and stable colonization of R. tritici for disease mechanism and nematode association.

• 한국동물위생학회지
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• 제27권4호
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• pp.371-378
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• 2004

The poultry farmers of rural area in Bangladesh usually prefer raising cockerel to broiler due to availability, low price of chicks, requirement of less space and feed, and high price of meat and the farmers believe that the cockerels are less susceptible to diseases in comparison to broilers. This study was carried out to observe the pathology of diseased cockerel in 3 farms of rural area in Bangladesh. A total of 974 birds were examined and the diagnoses of different disease/conditions were based on the history, clinical signs, characteristic gross, tissue alterations, clinical pathology and isolation and identification of the pathogenic organisms. The diseases in this study included infectious bursal disease, yolk sac infection, vitamin E deficiency, coccidiosis, and other diseases. The proportionate mortality rate were $7.29\%,\;0.62\%,\;0.72\%,\;0.21\%\;and\;0.10\%$, respectively, which indicated that most of the fatal causes of death were due to infectious bursal disease. Age group of 2-8 week old were the most susceptible to this disease and E coli was suggested as a cause of yolk sac infection. The data also suggested that the coccidiosis in rural areas of Bangladesh has decreased due to awareness of the farmers and routine use of coccidiostates.

• Pediatric Infection and Vaccine
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• 제9권1호
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• pp.100-103
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• 2002

Streptococcus milleri Group Bacteria(SMG)는 인간의 정상 세균총이면서 농양 형성을 잘 하는 병원균으로도 작용하지만 그 병원성에 대해서는 잘 알려져 있지 않다. 따라서 SMG 감염시 경각심을 갖고, 적절한 치료에도 증상이 지속될 때에는 병변 이외의 다른 곳에 농양이 형성되어 있는지 반드시 살펴보아야 한다.