• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.75-86
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• 2002

Outbreaks from September 1999 to July 2000 of blackleg in 4 milking and fatting cattle farms in the vicinity of Munkyong(northwestern part of Gyeongbuk province) were investigated biochemical characteristics of isolates and were surveyed epidemiological works during the period of 2 months from August to September 2000. Clostridium chauvoei, the etiological agent of blackleg is a serious pathogen of cattle and sheep causing fever, depression and lameness with high mortality in growing phase of 6 to 18 months old mainly beef cattle. Biochemical and cultural properties of 4 isolated Cl chauvoei were identical to those of reported results and isolates were susceptible to ampicillin, bacitracin, chlorarnphenicol, cephalothin, ciprofloxacin, erythromycin, norfloxacin, penicillin, and tetracycline, while they were resistant to amikacin, colistin, gentamicin, kanamycin, neomycin, streptomycin and trimethoprim-sulfamethoxazole. In the results of epidemiological survey, outbreak farms that concentrated region of milking or fatting cattle in each sites were so close contact within a radius of about 1km that they are separated only by wire fence or shrub harrier and flies, rodents, wild cats and birds could have the chance to move around between those farms. The origin of the outbreak blackleg were uncertain, but the transmission between farms were mainly through the movement of farm personnel, vehicles which were struck the feces or manures from farm and other mechanical factors such as flies, rodents and birds furthermore occurred 4 farms were not vaccinated. In conclusion, a periodic disinfection, vaccination and quarantine prevention are ideal methods of damage reduction by blackleg.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.317-323
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• 2000

Molecular genetic techniques can now be applied to the development of advanced plant genotypes, either through genetic transformation or genomic approaches which allow researchers to transfer specific traits using molecular markers. In this paper, we discuss the use of these techniques towards understanding the genetics of blackleg resistance in Brassica. In a comparative mapping study between Arabidopsis thaliana and Brassica napus, 6 R-ESTs, 7 B. napus RFLP markers and a B. napus EST were located in a collinear region of N7 (B. napus) and chromosome 1 (A. thaliana). One of the A. thaliana R-ESTs and 4 of the B. napus RFLPs co-segregated and mapped to the LmRl locus for blackleg resistance. Introgression of blackleg resistance from wild relatives is also investigated with the possibility of accelerating the introgression process via marker assisted selection.

• Research in Plant Disease
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• v.11 no.2
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• pp.140-145
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• 2005

A collection of 12 Erwinia carotovora strains from blackleg diseased potato in Jeju island was characterized genetic diversity by 5. cayotovora subsp. atposeptica (Eca)-specific PCR, PCR-RFLP of the two genes (16S rRNA and pel) and repetitive sequence PCR (ERIC-PCR). The results were compared with those of the other E. carotovora representative strains. None of the blackleg strains produced PCR amplicons with Eca-specific primers in contrast to the single 690 bp amplicon obtained with Eca strains. In addition, on the basis of pel gene RFLP with Sau3AI, the blackleg strains belonged to the pattern 2 whereas Eca strains belonged to the other one (pattern 3). By analysis of 16S rDNA RELP generated with HinfI, the most strains including the E. carotovera subsp. carotovora (Ecc) representative strains used in this study belonged to the pattern 1 whereas the blackleg strains belonged to the pattern 2 except for one strain. Moreover, ERIC-PCR analysis showed that the blackleg strains were closely related to each other and had an unique DNA band. Based on these molecular approaches, we have confirmed that the blackleg disease of potato is caused by a different E. carotovora from Eca and Ecc in Jeju island.

• Korean Journal of Veterinary Pathology
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• v.2 no.1
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• pp.53-60
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• 1998

A fourteen-month-old Holstein bull from a private cattle fattening farm at Ansung county in Kyunggi Province Korea was submitted on August 2nd 1997, for examination at the Pathology Division of the National Veterinary Research Institute. The bull died within 24 hours after developing clinical signs of abrupt inertia, complete anorexia high fever(40.3℃) diffuse severe emphysematous swelling of upper part of the right hind leg lateral recumbancy and paralysis. At necropsy diffuse severe subcutaneous redness and influx of serosanguinous exudate containing gas bubbles had accumulated under the thorax right hip and upper region of right hind leg. Muscles in upper right hind leg were blackish to dark red and yellowish brown in color. Muscle bundles were dry and separated by gas bubbles and serosanguinous fluids and muscles sections from affected regions floated in water. Histopathologically muscle fibers were partially or entirely degenerated fragmented and separated by exudate and gaseous substance mixed with polymorphonuclear cells. Blood vascular walls in affected regions showed severe acute fibrinoid necrosis. Typical large rod-shaped bacteria with or without oval central to subterminal spores were frequently observed in tissue sections stained with H-E and Gram stain. The large Gram-positive anaerobic endospore-producing rods were isolated from the suspension of muscle lesions. Isolated bacteria were identified as Clostridium(CL) chauvoei and CL. sordellii by biochemical tests. This case was diagnosed as blackleg based on the typical clinical signs gross finding histopathological observation and bacteriological results. This is the first case report on blackleg associated with Cl. chauvoei and Cl. sordellii in Holstein cattle in Korea.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.194-199
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• 2021

Blackleg is a serious disease in Brassica plants, causing moderate to severe yield losses in rapeseed worldwide. Although China has not suffered from this disease yet (more aggressive Leptosphaeria maculans is not present yet), it is crucial to take provisions in breeding for disease resistance to have excellent blackleg-resistant cultivars already in the fields or in the breeding pipeline. The most efficient strategy for controlling this disease is breeding plants with identified resistance genes. We selected 135 rapeseed accessions in Sichuan, including 30 parental materials and 105 hybrids, and we determined their glucosinolate and erucic acid content and confirmed 17 double-low materials. A recently developed single-nucleotide polymorphism (SNP) marker, SNP_208, was used to genotype allelic Rlm1/rlm1 on chromosome A07, and 87 AvrLm1-resistant materials. Combined with the above-mentioned seed quality data, we identified 11 AvrLm1-resistant double-low rapeseed accessions, including nine parental materials and two hybrids. This study lays the foundation of specific R gene-oriented breeding, in the case that the aggressive Leptosphaeria maculans invades and establishes in China in the future and a robust and less labor consuming method to identify resistance in canola germplasm.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.71-75
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• 1972

Due to the fact that an inactivated anthrax vaccine may show no or lower immunogenicity and stability, a number of spore vaccines were exclusively used worldwide. In these studies non or less allergic strain of anthrax bacillus was selected and made a capsulated vegetative organisms. Anthrax organisms of a virulent strain were cultivated on sodium bicarbonate medium with or without adding I-alanine in which B. anthracis grew luxuriantly without forming spores. Inactivation of the organisims was carried out at $37^{\circ}C$ water bath for 3 days after the bacterial culture was mixed with formalin in a final concentration of two per cent. Aluminum hydroxide gel was added to the mixture of anthrax and blackleg bacterin. Guinea pigs were injected with the vaccine via subcutaneous or intramuscular route and challenged after three weeks, and the possibilities of protection was tested. Throughout the studies, the vaccines possibly protected the vaccinated guinea pigs more than 80 per cent compared to that of the controls. This experimental results strongly suggest that the vaccine may possibly applicable to the prevention of bovine anthrax and blackleg.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.149-154
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• 2003

Potato blackleg disease caused by Erwinia carotovora subsp. atroseptica has been a serious problem in Korea. It was previously reported that four mixtures [streptomycin (9.3 ppm) + copper oxide (171.6 ppm)/copper hydroxide (146.3 ppm), streptomycin sulfate (7.0 ppm)+copper oxide (171.6ppm)/copper hydroxide (146.3 ppm)] were effective for the control of E. carotovora subsp. atroseptica. in in vitro test. Using those four mixtures and two antibiotics [streptomycin (81.4 ppm) and streptomycin sulfate (61.3 ppm)], the effectiveness of control for E. carotovora subsp. atroseptica. was conducted in the field. Two antibiotics showed over 60% of control efficacy under different soil conditions, while mixtures of two antibiotics with copper compounds did not show any control effects on the infected seed potato. Two mixtures [streptomycin (27.9 ppm)+copper hydroxide (438.9 ppm), streptomycin sulfate (21.0 ppm) + copper oxide (514.8 ppm)] were effective in the control of potato blackleg disease on the infected potato plants under different climate conditions.

• Journal of the korean veterinary medical association
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• v.34 no.4
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• pp.253-257
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• 1998

동물에서 발생되는 질병의 수는 헤아릴 수 없이 많으며, 병인체도 다양하다. 이러한 질병을 효과적으로 관리하기 위하여, 우리나라의 가축전염병예방법(개정법률 제 4,885호; 1995. 1. 5)에는 제1종 전염병 26종과 제 2종 전염병 28종, 총 54종을 법정가축전염병(法定家畜傳染病)으로 지정해 놓고 있다. 최근에 들어, 1996년 3월에 영국에서 소해면형뇌증 (일병 광우병, BSE)이 인체에서의 변형 크로이츠휄트-야곱병 (v-CJD)과 관련하여 세계적인 주목을 받음은 물론 유럽연합 (EU)을 중심으로한 쇠고기의 국제교역에 크게 영향을 미치고 있으며, 지난해(1997) 3월에는 대만에 구제역 (口蹄疫, FAD)이 발생하여, 여러 양돈장에 급속히 퍼져, 대만의 수출주력 산업인 양돈업의 붕괴를 가져왔을 뿐만 아니라 국가적인 경제위기를 초래하였으며, 연간 약 9조원의 경제적인 손실이 예상되고 있고 양돈경기 회복을 위하여는 막대한 자금(약 40조원)과 긴 세월(최소 4-5년)이 필요할것으로 생각되고 있다. 한편, 국제적으로는 아주 전통적인 질병이며 한동안 자취를 감추었던 광견병과 기종저가 개발하여 피해를 입히고 있으며, 아주 최근에 알려진 새로운 원충성 유산증을 일으키는 네오스포라증도 확인되고 있다. 본 편에서는, 최근 국내에서 특히 문제시 되고 있는 풍토병인 기종저(blackleg)에 대하여 그 발생실태와 임상진단, 방역대책 등에 관하여 고찰해 보고자 한다.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.97-119
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• 1972

Studies on modified complement fixation (MCF) test of antiblackleg bovine serum were made and the results obtained were summarized as followings. 1. The most satisfactory antigen for the MCF test among various materials studied was found to be the vegetative cells of Cl, chauvoei grown in cooked meat medium (CMM) containing 0.5mM l-(alpha) alanine and 0.1mM manganese. The antigen was prepared by inoculating the spores of Cl. chauvoei, heated at $70^{\circ}C$. for 30 minutes, into the CMM followed by incubation at $37^{\circ}C$. for 15 hours. 2. An active component contained in the factor serum of fresh normal rabbit serum was found to be C'4 fraction. It was also shown that, furthermore, DEAE cellulose sieved C'4 fraction of the factor serum enhanced antibody titer and the highest antibody titer was resulted by the addition of 0.03 ml, of the factor serum to each tube. 3. More than four fold increases of antibody titer, in antiblbckleg bovine serum-antigen system, was made with the MCF test than that with the direct complement fixation test. 4. The MCF antibody titer of cattle vaccinated against blackleg was 128 until seven month and 64 for five months thereafter.

• Korean Journal of Veterinary Service
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• v.37 no.3
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• pp.157-164
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• 2014

Clostridium chauvoei is the etiologic agent of blackleg, a high mortality rated disease infection mainly cattle. In the present study, the partial sequences of 16S rRNA and flagellin gene of C. chauvoei isolated in Jeonbuk, Korea were determined and compared with those of reference strain. Oligonucleotide primers were designed to amplify a 811 bp fragment of 16S rRNA gene and 1229 bp fragment of flagellin gene. Sequencing analysis of 16S rRNA gene showed high homology to the reference strains ranging 82.3% to 100%, while flagellin gene were different from published foreign clostridia, showing 98.7% to 72.0% nucleotide sequence homology. Phylogenetic analysis based on 16S rRNA gene revealed the close phylogenetic relationship of C. chauvoei and C. septicum in cluster I, which includes C. carnis, C. tertium, C. quinii, C. celatum, C. perfringens, C. absonum, C. botulinum B. Phylogentic analysis also revealed that flagellin gene formed a single cluster with C. chauvoei, C. septicum, C. novyi A, C. novyi B, C. tyrobutylicum, C. acetobutylicum. The genetic informations obtained from this study could be useful for the molecular study of C. chauvoei.