• Parasites, Hosts and Diseases
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• 제59권6호
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• pp.639-643
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• 2021

Enterocytozoon bieneusi is a microsporidian pathogen. Recently, the equestrian population is increasing in Korea. The horse-related zoonotic pathogens, including E. bieneusi, are concerns of public health. A total of 1,200 horse fecal samples were collected from riding centers and breeding farms in Jeju Island and inland areas. Of the fecal samples 15 (1.3%) were PCR positive for E. bieneusi. Interestingly, all positive samples came from Jeju Island. Diarrhea and infection in foals were related. Two genotypes (horse1, horse2) were identified as possible zoonotic groups requiring continuous monitoring.

• The Plant Pathology Journal
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• 제19권3호
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• pp.133-137
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• 2003

Seedborne fungus Bipolaris spicifera, which has not been previously reported in Korea, was detected from import-ed grass seeds in the country. The most frequently detected fungi from the seeds were Fusarium species, Ulocladium atrum, B. spicifera, Alternaria, and Cuvularia lunata among 17 different seed samples of the family Gramineae. Detection frequencies of B. spicifera were 11,8,5% in Bermuda grass, tall fescue, and mixed lawn grass imported from USA, respectively, and 9％ in mixed lawn grass imported from Italy. This suggests that important seedborne pathogen could be spread between countries through seed sources. The pathogen was seed-transmitted causing damping-off of Bermuda grass seedlings and showed strong pathogenicity to vice, corn, Bermuda grass, sorghum, and tall fescue. However, it did not infect wheat and blue grass.

• Mycobiology
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• 제32권4호
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• pp.186-189
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• 2004

The study on the cultural characteristics of Bipolaris spicifera was conducted to provide with information for the identification, and inoculation studies, etc. B. spicifera grew well at $30{\sim}35^{\circ}C$ and wide range of pH $5.0{\sim}9.0$. However, the fungal growth was retarded at pH 4.0 and 10.0, respectively. Conidia were germinated with 70% at $30^{\circ}C$ but maintained 50% germination even at $40^{\circ}C$, indicating that this pathogen could infect plants at relatively high temperature. The pathogen could not produce conidia under 24 hr fluorescent light condition for 7 days. In contrast, it produced many more conidia at 24 hr dark condition.

• 원예과학기술지
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• 제18권1호
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• pp.22-27
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• 2000

배를 캐나다 등 외국에 수출할 시는 수출 상대국의 검역요건에 맞추어 주어야 한다. 수출국 특히 캐나다에 수출되는 배의 검역상 문제점을 찾아 그 해결법을 제시하고자 수출 조건에서 수출 단계별 검역규제병해충을 조사하였다. 조사 결과 복숭아명나방과 복숭아순 나방이 발견되었으나 이들은 저온처리로 인하여 모두 사멸되었다. 해충은 복숭아심식나방류 유충이 과실로 이동되는 시기에 방제를 소홀히 한 생산지 과실에서 발견되었으므로 복숭아명나방 등 심식나방류 유충이 과실로 이동되는 시기에 예찰을 철저히 하여 적기방제 하는 것이 필요하다. 한편 병원균은 과실의 선과 작업과 이동할 때 생긴 압상, 자상 등 상처를 통하여 Penicillium sp. 및 Alternaria sp.의 부생균이 감염된 것이 발견되고 검역병원균은 발견되지 않았다. 그러나 이들 병원균도 비록 비검역병원균이라고 하지만 부패과실이 일정비율 초과할 경우 수출자가 수입자에게 이를 보상하여야 하므로 수출배 중 외피가 얇은 황금배 등은 수확 후 운송과정과 선과장 선과 작업 중에 특별한 주의가 요구된다.

• 한국균학회지
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• 제44권2호
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• pp.103-107
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• 2016

본 연구는 국내 주요 식물검역관리 대상 Phytophthora pinifolia를 대상으로 신속하고 정확한 병원균 종동정 및 검출을 위해 Ypt1 유전자 염기서열을 활용하여 제작된 종 특이적 분석용 분자마커와 다양한 PCR 기법을 활용하여 병원균들에 대한 다양한 검출기술의 표준화 및 최적 검출 시스템 구축을 통하여 실제 검역검역 현장에서 활용 가능한 병원균 존재여부의 신속, 정확한 판별기법을 개발하고자 수행하였다. Ypt1 영역의 염기서열을 기초로 선발된 종 특이적 primer는 1~10 pg의 검출민감도를 가지며 193 bp의 종 특이적 PCR 증폭산물을 형성시켰다. 또한 선발된 종 특이적 primer의 종 특이성을 확인하기 위하여 국내 식물검역대상에 포함된 Phytophthora속 종들과 주요 식물병원균들을 대상으로 conventional PCR과 real-time PCR을 수행한 결과 목표로 한 P. pinifolia DNA에서만 특이적 PCR 증폭산물을 확인할 수 있었다. 선발된 종 특이적 primer에 대한 PCR의 검출 민감도를 확인했을 때 conventional PCR의 검출민감도는 1~10 pg이었다.

• 한국동물위생학회지
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• 제41권3호
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• pp.203-210
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• 2018

Pasteurella multocida is an opportunistic organism that plays a significant role in porcine respiratory disease complex (PRDC). In the current study, we provide nationwide information of P. multocida isolates from pneumonic lungs of slaughter pigs by determining their prevalence, subspecies, biovars, capsular types, virulence-associated genes, and minimum inhibitory concentrations. P. multocida was the second most frequently confirmed (19.2%) bacterial pathogen and most of the isolates (88.9%) showed simultaneous infection with other respiratory pathogens, especially Mycoplasma hyopneumoniae (63.3%, P<0.001) and porcine circovirus type 2 (53.3%, P=0.0205). Of 42 isolates investigated, 41 (97.6%) were identified as P. multocida subspecies multocida, and only one isolate was identified as subspecies septica (biovar 5). All the isolates were capsular type A and the most prevalent biovar was biovar 3 (40.5%), followed by biovar 2 (31.0%). Comparing virulence-associated genes and biovars, all biovar 2 isolates exhibited $hgbB^-pfhA^+$ (P<0.001); all biovar 3 (P=0.0002) and biovar 13 (P=0.0063) isolates presented $hgbB^+pfhA^-$. Additionally, all biovar 2 (P=0.0037) isolates and most of biovar 3 (P=0.0265) isolates harbored tadD. P. multocida showed the highest resistance levels to oxytetracycline (73.8%), followed by florfenicol (11.9%). Continuous monitoring is required for surveillance of the antimicrobial resistance and new emerging strains of P. multocida in slaughter lines.

• 한국임상수의학회지
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• 제28권1호
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• pp.113-121
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• 2011

Foot-and-mouth disease (FMD) is a severe vesicular disease of cloven-hoofed animals including domesticated ruminants and pigs. Acute clinical signs may be mild in sheep and goats but are associated with lameness in pigs and mouth lesions with vesicles in cattle. The required condition for a successful pathogen appears to be the ability to counteract both the host innate and adaptive immune response. FMD virus (FMDV) inhibits the induction of antiviral molecules and interferes with the secretory pathway in the infected cell. The surface expression of Major Histocompatibility Complex (MHC) class I molecules is reduced in infected cells. Thus, the ability of the host to recognize and eliminate virus infected cells is decreased. Furthermore, FMDV infection results in a rapid, but transient lymphopenia, reducing the number of T and B cells, and affecting T cell function. The virus appears to premature apoptosis-mediated cell death because it has a very short replication cycle and is able to rapidly produce large amounts of virus. FMDV engages the host protective response at multiple steps to ensure its effective replication and pathogenesis. This review describes the recent pathological and immunological studies to overcome the powerful abilities of FMDV to counteract defense mechanism of host.

• 한국동물위생학회지
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• 제42권4호
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• pp.275-278
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• 2019

Blindness was observed in five calves born from cattle fed only a commercial feed of growing stage and dried rice straws for about two years in a farm in Gyeongsangbuk-do province. Three of them died within a month after birth, and a body and sera of his mother and other 19 cattle were submitted for diagnosis. At necropsy, the calf was very weak and filled with cerebrospinal fluid in the cerebrum. Any histopathological lesion including atrophy of death of optic nerve cells was not observed, but the irregular proliferation such as lace pattern of choroidal cells and lymphocytic infiltration just below choroid was observed. No pathogen was detected as a result of the etiological tests on the internal organs of calves and bloods. In addition, the levels of serum vitamin A in different affected and his mother cattle were all lower than normal. Finally, we determined this case as an encephalopathy caused by maternal vitamin A deficiency in a calf. This report is an extreme example of how important it is to supply adequate s diets and a good quality of hay for each stage of growth in cattle.

• 대한수의학회지
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• 제50권1호
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• pp.29-35
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• 2010

Yersinia (Y.) ruckeri has been recognized as a serious bacterial pathogen to several kinds of fish, including rainbow trout. However, there are no reports about the characteristics and pathogenicity of Y. ruckeri isolated from farm-cultured eels. In this study, we isolated and characterized Y. ruckeri from the farm-cultured eel Anguilla japonica in Korea. We investigated the phenotypic and genotypic characteristics of Y. ruckeri and tested the virulence of Y. ruckeri isolates on experimentally infected eels. Examination of the flagellar morphology of Y. ruckeri by electron microscopy showed peritrichous flagella in its cell body. Biochemical reaction studies showed overall identical profiles between the isolates and the reference strain of Y. ruckeri in API 20E and API ZYM tests. We sequenced the 16S rRNA of the Y. ruckeri (1,505 bp) for the genotypic characterization (National Center for Biotechnology Information accession number EU401667). Comparison of the 16S rRNA sequences with previously reported Y. ruckeri strains revealed similar phylogenetic relationships. In the virulence assay of the Y. ruckeri on eels, the eels exhibited listlessness, but Y. ruckeri was reisolated from those of the gills and kidneys.

• The Plant Pathology Journal
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• 제17권1호
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• pp.62-66
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• 2001

Detection of Xanthomonas axonopodis pv. citri (Xac) on citrus fruits for exporting is usually made by bacteriophage test (BPT) to demonstrate the pathogen-free status. BPT has rather time-consuming and complicate procedures for dealing with massive samples to be inspected. In this study, enzyme-linked immunosorbent assay (ELISA) was applied to detect Xac on fruits, and compared with BPT. In ELISA, positive reactions occurred in the bacterial densities of $3\times10^5$ cells/ml or more. To detect the bacterial infection on citrus fruits with a density of lower than $3\times10^5$ cells/ml, the bacterial suspensions were mixed with fruit rinse water and incubated in broth medium. Ordinary peptone sucrose broth (PSB) was not a proper medium for increasing Xac density specifically enough to be detect by ELISA. On the other hand, modified PSB (MPSP) amended with Fe-EDTA (0.25 g/$\ell$) and 2.5% potato-dextrose broth sufficed to differentiate uninfected and infected citrus fruits by ELISA after 24 h incubation of the fruit rinse water. Using various citrus samples from infected and uninfected fields, efficiencies in detecting Xac on fruits were compared between ELISA and BPT. For infected fruits samples, ELISA detected Xac by 100%, while BPT by about 44%, indicating that the detection efficiency was improved by 23.5% by ELISA, compared to BPT. In addition, ELISA has simpler procedures for testing and is less time-consuming than BPT, suggesting that ELISA may be accurate and simple method to detect Xac on citrus fruits.