• 한국동물위생학회지
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• 제43권2호
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• pp.53-58
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• 2020

Enterovirulent Escherichia coli are among the most important causes of diarrhea in cattles. Between January and December, 2017, a total of 150 stool specimens from cattles were investigated for enterohaemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC) using real-time PCR. 131 E. coli were isolated from feces. The most frequently isolated pathotype in feces was EHEC (37 isolates). EPEC, ETEC and EAEC were detected in feces with 14, 7 and 3 respectively. EIEC was not detected. Antimicrobial resistance test was performed by agar disc diffusion method with 14 antimicrobials. Enterovirulent E. coli isolates showed the highest antimicrobial resistance to ampicillin 61.3%, followed by tetracycline 54.5% and streptomycin 45.5%. They had low resistance to amikacin 11.4%. Of 44 isolates, 37 (84.1%) were resistant to more than 2 antimicrobials. futher study a highest antimicrobial susceptibility to trimethoprim/sulfamethoxazole 50.0% and florofenicol 47.7%.

• The Plant Pathology Journal
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• 제35권1호
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• pp.1-10
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• 2019

Wheat blast occurred in Bangladesh for the first time in Asia in 2016. It is caused by a fungal pathogen, Magnaporthe oryzae Triticum (MoT) pathotype. In this review, we focused on the current status of the wheat blast in regard to host, pathogen, and environment. Despite the many efforts to control the disease, it expanded to neighboring regions including India, the world's second largest wheat producer. However, the disease occurrence has definitely decreased in quantity, because of many farmers chose to grow alternate crops according to the government's directions. Bangladesh government planned to introduce blast resistant cultivars but knowledges about genetics of resistance is limited. The genome analyses of the pathogen population revealed that the isolates caused wheat blast in Bangladesh are genetically close to a South American lineage of Magnaporthe oryzae. Understanding the genomes of virulent strains would be important to find target resistance genes for wheat breeding. Although the drier winter weather in Bangladesh was not favorable for development of wheat blast before, recent global warming and climate change are posing an increasing risk of disease development. Bangladesh outbreak in 2016 was likely to be facilitated by an extraordinary warm and humid weather in the affected districts before the harvest season. Coordinated international collaboration and steady financial supports are needed to mitigate the fearsome wheat blast in South Asia before it becomes a catastrophe.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.143.3-144
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• 2003

A Korean isolate of Pepper mild mottle virus (PMMoV-Kr) was isolated from a diseased pepper crop in Chunchon, Korea. The isolate was biologically purified on Nicoticaa tabacum cv. Xanthi-nc by successive single local transfer steps, and propagated on N. tabacum cv. Samsun. PMMoV-Kr could systemically infect on N. glauca, N. benthmiana, N. occidentalis and Lycopersicon esculentum, which is typical of known isolates of PMMoV. PMMoV-Kr belongs to the pathotype P1,2 based on pepper-tobamoviral indicator experiments; Capsicn chinone harboring L3 gene revealed resistant (necrotic local lesion on inoculated leaf, HR) whereas L+, L1 and L2 pepper plants expressed susceptible reactions of mosaic systemic symptoms for the isolate. To confirm the pathology and delineate symptom determinant of the isolate, full-length cDNAs of PMMoV-Kr were amplified by RT-PCR with a primer set corresponding to the 5'- and 3'-ends of PMMoV. The RT-PCR molecules amplified from genome RNA of the isolate was cloned into the pUC18 vector. Full-length cDNA clones constructed under the control of the T7 RNA promoter could be successfully transcribed to produce in vitro transcript RNA. Infectivity of the capped transcripts and its progeny virus was verified by Western blot and RT-PCR analyses.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.50-50
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• 2015

Both agriculture and local tourism of Kagoshima prefecture where is located on the south-western region of the Japanese mainland, are the important industries. Although cabbage (Brassica oleracea) has been cultivated in recent decades in Kagoshima, clubroot disease caused by Plasmodiophora brassicae had never been observed. However, the disease in cabbage was reported in four regions last couple years. Our survey showed that one region is infested severely whereas others are slightly. In the most widely infested region, the disease was also observed in turnip rape (Brassica rapa) which is grown as ornamental plants for landscape design in early spring and important tourist attraction. Consequently, both agriculture and local tourism are damaged by clubroot. The increase of clubroot incidence in this region might be caused by significant increase of cabbage production, the expansion of cropping season throughout the year and continuous turnip rape cultivation in the same fields of cabbage for almost three decades. Therefore we are trying to estimate the risk of clubroot damage cultivation throughout the year in this region. We collected five isolates of resting spores and identified them as race 3, 4 and 9 by Williams' method, and as pathotype group 3 and 4 by classification system using clubroot resistant (CR) $F_1$ cultivars of Chinese cabbage as differential hosts as described in Hatakeyama et al.(2004). Furthermore, we found that these populations were avirulent to commercial CR cabbages. These results indicate that introduction of CR cabbage and breeding of turnip rape are the effective measures to solve our problem.

• 대한수의학회지
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• 제52권4호
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• pp.213-221
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• 2012

A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices ${\geq}1.81$ in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at $56^{\circ}C$. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype VI. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

• 한국가금학회지
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• 제35권3호
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• pp.225-240
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• 2008

Marek's disease virus(MDV) is a highly cell-associated, lymphotropic $\alpha$-herpesvirus that causes paralysis and neoplastic disease in chickens. The disease has been controlled by vaccination which was provided the first evidence for a malignant cancer being controlled by an antiviral vaccine. Marek's disease pathogenesis is complex, involving cytolytic and latent infection of lymphoid cells and oncogenic transformation of $CD4^+$ T cells in susceptible chickens. MDV targets a number of different cell types during its life cycle. Lymphocytes play an essential role, although within them virus production is restricted and only virion are produced. Innate and adaptive immune responses develop in response to infection, but infection of lymphocytes results in immunosuppressive effects. Hence in MDV-infected birds, MDV makes its host more vulnerable to tumour development as well as to other pathogens. All chickens are susceptible to MDV infection, and vaccination is essential to protect the susceptible host from developing clinical disease. Nevertheless, MDV infects and replicates in vaccinated chickens, with the challenge virus being shed from the feather-follicle epithelium. The outcome of infection with MDV depends on a complex interplay of factors involving the MDV pathotype and the host genotype. Host factors that influence the course of MD are predominantly the responses of the innate and adaptive immune systems, and these are modulated by: age at infection and maturity of the immune system; vaccination status; the sex of the host; and various physiological factors.

• The Plant Pathology Journal
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• 제24권4호
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• pp.423-432
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• 2008

The difference of carbon source utilization and fatty acid composition between the pathotypes of Xanthomonas strains, which causing citrus bacterial canker was compared, and the physiochemical characteristics were used to analyze relationship of the strains for the first time. The pattern of several carbon sources utilization and fatty acids composition reliably discriminated the pathotypes of Xanthomonas strains. The dendrogram which was constructed by 95 carbon source utilization profiles differentiated X. axonopodis pv. citri A, $A^*$ and $A^w$ from the other pathotypes. When the dendrogram was drawn by combined analysis of carbon source utilization pattern and fatty acid composition, X. axonopodis pv. aurantifolii B, C and X. axonopodis pv. citrumelo formed a distinct cluster. The difference of carbon source utilization and fatty acid composition could be used effectively for the identification of pathotypes of citrus bacterial canker. The physiochemical characteristics strongly indicated that the strains isolated in Korea belong to X. axonopodis pv. citri A type. The cluster analysis by the band patterns of ERIC-, BOX- and REP-PCR allowed the discrimination of the pathotypes isolated from Korea. However, the rep-PCRs could not differentiate X. axonopodis pv. citri A types from $A^*$ and $A^w$ types. The overall results of metabolic profiles and rep-PCRs strongly indicated that the Korean isolates are X. axonopodis pv. citri A type.

• 한국응용곤충학회지
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• 제19권1호
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• pp.51-55
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• 1980

수도 흰빛마름병 이병엽과 Kresek 발병주로부터 분리한 I균군(각5균주), II균군(각4균주)의 18균주를 "밀양23호"및 "유신" 품종 5엽기의 전개엽에 침접종한후 수도체내에서의 균증식과 병반장율 및 Kresek 발병율을 비교조사하여 균주간차이를 비교하였고, 밀양23호외28품종에 대해 II, IV균군을 사용하여 침접종및 근단접종법으로 품종간 저항성을 조사한 결과 1. 각균주간 수도체내에서의 증식은 큰 차이를 볼수 없었으나 "Kresek"발병주로부터 분리된 균주가 병반장률이 약간 높은 경향을 나타내었다. 2. Kresek 발병은 흰빛잎마름병 이병주에서 분리한 균주와 "Kresek"발병주로부터 분리한 균주간에는 아무런차이를 인정할수 없었고, 모두 발병을 볼수있었다. 3. Kresek에 대한 품종저항성에서는 흰빛잎마름병의 저항성반응과 비슷한경향을 나타내고 있으나 Wase Aikoku 품종군에서도 발병을 볼수있었다. 4. 황옥품종군인 "IR20"은 Kresek에라해 고도의 저항성반응을 나타내었다. 5. 접종반응으로는 근단접종법에서 침접종법에 비해 더욱 많은 발병율을 볼수있었다.

• Molecules and Cells
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• 제25권2호
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• pp.205-210
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• 2008

To develop molecular markers linked to the $L^4$ locus conferring resistance to tobamovirus pathotypes in pepper plants, we performed AFLP with 512 primer combinations for susceptible (S pool) and resistant (R pool) DNA bulks against pathotype 1.2 of pepper mild mottle virus. Each bulk was made by pooling the DNA of five homozygous individuals from a T10 population, which was a near-isogenic $BC_4F_2$ generation for the $L^4$ locus. A total of 19 primer pairs produced scorable bands in the R pool. Further screening with these primer pairs was done on DNA bulks from T102, a $BC_{10}F_2$ derived from T10 by back crossing. Three AFLP markers were finally selected and designated L4-a, L4-b and L4-c. L4-a and L4-c each underwent one recombination event, whereas no recombination for L4-b was seen in 20 individuals of each DNA bulk. Linkage analysis of these markers in 112 $F_2$ T102 individuals showed that they were each within 2.5 cM of the $L^4$ locus. L4-b was successfully converted into a simple 340-bp SCAR marker, designated L4SC340, which mapped 1.8 cM from the $L^4$ locus in T102 and 0.9 cM in another $BC_{10}F_2$ population, T101. We believe that this newly characterized marker will improve selection of tobamovirus resistance in pepper plants by reducing breeding cost and time.

• The Plant Pathology Journal
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• 제21권3호
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• pp.207-213
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• 2005

Cultural, morphological and pathogenic variation in Indian isolates of Ascochyta rabiei, the causal agent of blight of chickpea, was investigated. Fungal isolates representative of seven agroclimatic regions in north western plain zones (NWPZ) of India showed variation in colony colour as mouse gray with green hue, light mouse gray with slate gray centre and gray with dark brown centre, when grown on chickpea dextrose agar (CDA). Conidiomatal color of the isolates varied from brown to slate gray and black. The number of conidiomata and conidia formed on CDA ranged from 49.7 to 90.7 and $5.5\times10^4\;to\;3\times10^5cm^{-2}$, respectively. The size of conidiomata and conidia of A. rabiei isolates varied from $274\times232{\mu}m\;to\;156\times116{\mu}m$, and from $14.0\times6.2{\mu}m\;to\;10.7\times4.6{\mu}m$, respectively. Fourteen A. rabiei isolates from the seven agroclimatic regions of NWPZ were evaluated for their virulence on 180 chickpea genotypes in controlled environment. Cluster analysis based on the disease rating on a 1-9 scale indicated higher similarity coefficient (> 0.65) between isolates from different agroecological regions, while few isolates from the same region had less similarity. The 14 isolates were grouped into eight pathotypes at > 0.5 similarity coefficient. Sixteen genotypes were identified as probable differentials to distinguish A. rabiei isolates.