• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.30.2-30
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• 1999

• The Plant Pathology Journal
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• v.33 no.2
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• pp.103-108
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• 2017

World wheat production is now under threat due to the wheat blast outbreak in Bangladesh in early March 2016. This is a new disease in this area, indicating the higher possibility of this pathogen spreading throughout the Asia, the world's largest wheat producing area. Occurrence of this disease caused ~3.5% reduction of the total wheat fields in Bangladesh. Its economic effect on the Bangladesh wheat market was little because wheat contributes to 3% of total cereal consumption, among which ~70% have been imported from other countries. However, as a long-term perspective, much greater losses will occur once this disease spreads to other major wheat producing areas of Bangladesh, India, and Pakistan due to the existing favorable condition for the blast pathogen. The wheat blast pathogen belongs to the Magnaporthe oryzae species complex causing blast disease on multiple hosts in the Poaceae family. Phylogenetic analysis revealed that the Bangladesh outbreak strains and the Brazil outbreak strains were the same phylogenetic lineage, suggesting that they might be migrated from Brazil to Bangladesh during the seed import. To protect wheat production of Bangladesh and its neighbors, several measures including rigorous testing of seed health, use of chemicals, crop rotation, reinforcement of quarantine procedures, and increased field monitoring should be implemented. Development of blast resistant wheat varieties should be a long-term solution and combination of different methods with partial resistant lines may suppress this disease for some time.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.181-189
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• 2011

A 5-month (May to November in 2009) monitoring program for five viral pathogens in litter, such as avian influenza virus A (AIV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), fowl adenovirus (FAdV), and chicken infectious anemia virus (CIAV) was conducted in 62 flocks at 31 broiler farms (two flocks in each farm) in Korea in 2009. Viral pathogens were examined twice (before and at the end of the rearing period) at 31 broiler farms, and included fresh litter (n = 16) and recycled litter (n = 15) farms. Thirty-seven viruses (14 IBVs, 2 IBDVs, 9 FAdVs, and 12 CIAVs) were isolated from 75% (12/16) and 73% (11/15) of fresh litter and reused litter farms during the period, respectively, indicating no difference in viral contamination rate between farms using new and reused litter. Of these isolates, three (two CIAVs and one IBDV) were isolated from recycled litter samples collected before the rearing period at three broiler farms, whereas the others (n=34) were isolated from fresh and recycled litter samples collected at the end of the rearing period. When the performances, involving viability, body weight, and feed conversion ratio, were compared, no significant differences were found between farms using fresh and recycled litter during the period.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.431-440
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• 2016

In 2004, bacterial spot-causing xanthomonads (BSX) were reclassified into 4 species-Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes-gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

• Korean Journal of Veterinary Research
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• v.57 no.4
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• pp.209-214
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• 2017

Wild raccoon dogs (Nyctereutes procyonoides koreensis) may play a role transmitting several pathogens to humans and pet animals. Information concerning the incidence of rabies, canine distemper virus (CDV), canine parvovirus (CPV), canine adenovirus type 2 (CAdV-2), canine parainfluenza virus type 5 (CPIV-5), and canine herpesvirus (CHV) is needed in wild raccoon dogs. In total, 62 brain samples of raccoon dogs were examined for rabies virus (RABV) and CDV, and 49 lung samples were screened for CDV, CAdV-2, CPIV-5, and CHV. No RABV, CAdV-2, CPIV-5, or CHV was identified, but nine CDV antigens (8.1%, 9/111) were detected. Moreover, 174 serum samples from wild raccoon dogs were screened for antibodies against the five major viral pathogens. The overall sero-surveillance against CDV, CPV, CAdV-2, CPIV-5, and CHV in wild raccoon dogs was 60.3%, 52.9%, 59.8%, 23.6%, and 10.3%, respectively. Comparisons of the sero-surveillance of the five pathogens showed that raccoon dogs of Gyeonggi province have slightly higher sero-positive rates against CDV, CPV, and CHV than those of Gangwon province. These results indicate high incidences of CDV, CPV, and CAdV-2 in wild raccoon dogs of two Korean provinces and a latent risk of pathogen transmission to companion and domestic animals.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.159-165
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• 2010

Field strains of Ornithobacterium rhinotracheale (OR) were tested on their virulence in specific pathogen free (SPF) embryonated chicken eggs and 3-week-old broilers. When infected with three different OR isolates (OR-161, OR-240 and OR-295) through yolk sac infection route, all strains appeared to be highly pathogenic with responsible mortality 66% and 100% within 12 days post infection (DPI). To test the virulence of OR in the commercial broilers, 3 week-old broilers were grouped depends on the inoculation route of OR isolate (OR-295) through five different infection routes; group 1 (IT: intratracheal), group 2 (IM: intramuscular), group 3 (IV: intravenous), group 4 (aerosol) and group 5 [Mixed: NDV (LaSota)+OR aerosol]. Within 5 to 7 days after inoculation, only broilers given NDV+OR were slightly depressed and coughing, and had mild facial redness. Grossly, foamy and yellow-white yogurt like exudate in the air sacs, predominantly in the abdominal air sacs was present. In histology, infiltration of the air sac epithelium and lamina propria by macrophage and polymorphonuclear granulocytes was seen with cell debris and inflammatory cells, correlated with the presence of OR antigen, as demonstrated by immunohistochemistry. Field strains of OR were able to induce high mortality in the embryonated chicken eggs, whereas broilers were less susceptible to OR infection. Interestingly, in the absence of NDV infection, the four groups of OR single infection only different route showed minimal and temporary microscopic air sac lesions. Thus, Newcastle disease virus (LaSota strain) showed triggering effects on the OR infection in chickens.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.25-32
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• 2015

Pseudomonas coronafaciens causes halo blight on oats and is a plant quarantine bacterium in many countries, including the Republic of Korea. Using of the certificated seed is important for control of the disease. Since effective detection method of P. coronafaciens is not available yet, PCR and TaqMan PCR assays for specific detection of P. coronafaciens were developed in this study. PCR primers were designed from the draft genome sequence of P. coronafaciens LMG 5060 which was obtained by the next-generation sequencing in this study. The PCR primer set Pc-12-F/Pc-12-R specifically amplified 498 bp from the 13 strains of P. coronafaciens isolated in the seven different countries (Canada, Japan, United Kingdom, Zimbabwe, Kenya, Germany, and New Zealand) and the nested primer set Pc-12-ne-F/Pc-12-ne-R specifically amplified 298 bp from those strains. The target-size PCR product was not amplified from the non-target bacteria with the PCR and nested primer sets. TaqMan PCR with Pc-12-ne-F/Pc-12-ne-R and a TaqMan probe, Pc-taqman, which were designed inside of the nested PCR amplicon, generated Ct values which in a dose-dependent manner to the amount of the target DNA and the Ct values of all the P. coronafaciens strains were above the threshold Ct value for positive detection. The TaqMan PCR generated positive Ct values from the seed extracts of the artificially inoculated oat seeds above 10 cfu/ml inoculation level. PCR and TaqMan PCR assays developed in this study will be useful tools to detect and identify the plant quarantine pathogen, P. coronafaciens.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1126-1140
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• 1999

Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific pathogen free chicks were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infection, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infection with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. The high dietary salt feeding groups such as IBHNa, IBHNC, HNa, HNC increased water intake, watery diarrhea, general subcutaneous edema and the high dietary calcium feeding groups such as IBHCa and IBHNC showed severe visceral gout. Two more than treated groups caused high mortality in comparison with the single treated groups. IB virus exposure significantly increased urate deposition and lymphocytic interstitial nephritis. Especially urate deposition dramatically increased when excess diet calcium was combined together. In excess diet salt treated groups enlarged edematous kidneys were observed and hypertrophy of glomeruli were showed. These results suggest that IB virus enhanced the incidence and severity on chicken renal failure clearly related to the quantity of salt and calcium.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1141-1150
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• 1999

Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific pathogen free chickens were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infection, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infection with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. Plasma $Na^+$, $Cl^-$, BUN, creatinine, calcium and uric acid values were examined. The results obtained were as follows ; IB virus and high dietary calcium combined treatment showed elevated plasma uric acid. BUN and creatinine values were not characteristic on chicken renal failure. But plasma uric acid values were increased according to renal lesion. Hypercalcemia and hyperuricemia did not induce urate deposition and mineralization in the kidney.