• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.569-574
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• 2005

Enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to reticuloendotheliosis virus (REV) at single serum dilution was standardized. REV HI, one of the Korean field isolates, was inoculated into chicken embryo fibroblast (CEF) cells and was harvested from the culture fluids and cells after 10 to 12 days. Viruses were purified by centrifugation at the $107,000{\times}g$ for 12 hours on 20, 30, 45% (W/V) sucrose gradient. Virus specific fraction was collected and used as ELISA antigen. To standardize ELISA, the optimal concentration of coating antigen ($1{\mu}g/well$) and conjugate (1/1000) was determined by corrected OD (OD value of positive serum-OD value of negative serum) and P/N ratio (OD value of positive serum/OD value of negative serum). To calculate ELISA titer by measuring absorbance at 1/400 single serum dilution, serum titrations were carried out for various sample sera together with standard positive and negative sera. The observed titers of serum samples were plotted against sample/positive (s/p) ratios at 1/400 serum dilution. From the above data, the ELISA titers could be calculated by the equation of $log_{10}$ ELISA titer = 2.2763 ($log_{10}$ s/p) + 3.482 (r = 0.93). For evaluating the sensitivity, the standardized method were compared with conventional agar gel immunodiffusion (AGID) test method using serum samples collected from REV infected field chicken flocks. Fifty seven of 60 samples (95%) were positive for REV by ELISA, whereas only 11 (18.3%) samples were positive by AGID test. This results suggested that the ELISA tests developed in this study could be used for detection of antibodies to REV with high sensitivity.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.44-52
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• 2011

Field surveys were conducted in 45 stone fruit orchards in seven districts of Isparta Province located in western Mediterranean region of Turkey important for stone fruit production. Leaf samples were collected from 175 trees showing virus-like symptoms. These samples were first tested by ELISA for five different RNA viruses including Apple mosaic ilarvirus (ApMV), Prunus necrotic ringspot ilarvirus (PNRSV), Prune dwarf ilarvirus (PDV), Plum pox potyvirus (PPV), Apple chlorotic leafspot trichovirus (ACLSV). While no ApMV and PPV infection was found, 46, 24 and 16 samples were tested positive for PDV, ACLSV and PNRSV, respectively, in ELISA showing about 45% of symptomatic trees in the region were infected with at least one of these viruses. In addition, it was found that nine sweet cherry trees were mixed infected with two or three of these viruses and PDV with an infection rate of 26.3% was the most widespread virus in symptomatic trees in western Mediterranean region. Thirty samples were selected and tested by a multiplex RT-PCR (mRT-PCR) for simultaneous detection of these viruses. While PPV was not detected, more than half of the tested 20 samples were individually or mixed infected with ApMV, ACLSV, PNRSV and PDV. The mRT-PCR results were confirmed by detection of these viruses individually in some of the field samples using RT-PCR with primes specific to each virus. Comparison of ELSA and mRT-PCR results of 30 samples showed that numbers of infected and mixed infected samples as well as infection and mixed infection rates were significantly higher in RT-PCR (20 and 66.7%) than in ELISA (14 and 46.7%). The results confirm that mRT-PCR is more sensitive than ELISA.

• Research in Plant Disease
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• v.15 no.1
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• pp.1-7
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• 2009

Viruses diagnosed on crops including rice plants from farmers or agricultural extension agencies cover the country were 11 species including Broad bean wilt virus 2 (BBWV2) in 2008. Tomato spotted wilt virus (TSWV) was the most important virus having the detection rate of 22.9%. Two viruses of Tomato yellow leaf curl virus (TYLCV) and Tobacco leaf curl virus (TLCV) inducing leaf yellow and curl diseases on tomatoes were occurred newly with the detection rate of 12.2% and 4.0%, respectively, in 2008. Rice stripe virus (RSV) was occurred on 869.5 ha mainly at Jindo and Haenam areas in Jeollanamdo province. At Jindo area, 12 plots were damaged severely with the infected hill rate of 83.8%. At the main production area of oriental melon at Seongju, almost all fruits from whole sale market at Seongju were infected with Cucumber green mottle mosaic virus (CGMMV) as the detection rate of 87%. The areas occurred TSWV in Korea were 25 totally from 2003 including 7 areas newly reported in 2008 including Naju in Jeoallanamdo. TSWV could be reduced as 0.1 % from 5.3% by covering insect proof net in vinyl house after chemical soil sterilization. Tomato yellow leaf curl disease was occurred on April in 2008 at Tongyoung area in Kyeongsangnamdo, and detected continuously at 13 areas, 7 in Kyeongsangnamdo, 4 in Jeollabukdo and 2 in Jejudo. Potato spindle tuber viroid (PSTVd) was occurred abruptly in a confined space of a civil breeding greenhouse and a cultivar evaluation field followed by disuse 17.4 M/T of potato tubers. No PSTVd was detected at 17 fields cultivated the related potatoes to the bred company by RT-PCR.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.385-389
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• 2011

A new reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the Potato leafroll virus (PLRV) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to address its advantages over RTPCR. RT-LAMP primers were designed from the open reading frame 3 (ORF3) sequence of PLRV. The RT-LAMP reactions were conducted without or with a set of loop primers. By real-time monitoring using Turbimeter, the RT-LAMP (with loop primers) detects PLRV in less than 30 min, compared to 120 min of RT-PCR. By adding fluorescent reagent during the reaction, final products of the RT-LAMP were fluorescently visualized under UV light or could be differentiated by naked-eye inspection under normal light. The RT-LAMP was extremely sensitive, about 2000-fold more sensitive than RT-PCR. This study presents great potential of the RT-LAMP for diagnosis and PLRV epidemiology because RT-LAMP method is speedy, sensitive, inexpensive, and convenient.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.185-188
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• 2001

According as many people use a computer newly, damage of computer virus and hacking is rapidly increasing by the crucial users. To block hacking that is intrusion of a person's computer and the computer virus that destroys data, a study for intrusion-detection of system and virus detection using a biological immune system is in progress. In this paper, we make a model of positive selection and negative selection of self-recognition process that is ability of T-cytotoxic cell that plays an important part in biological immune system. So we embody a self-nonself distinction algorithm in computer. To prove the efficacy of self-recognition algorithm, we use simulations by a cell change and a string change of self file.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.48-51
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• 2000

Citrus tristeza virus (CTV) was identified form CTV-infected early satsuma mandarin (Citus unshiu) and yuzu (C.junos) by RT-PCR. The total RNAs were isolated from citrus bark and seaf tissues infected with CTV and reverse transcription was followed with primers designed for amplifying CTV coat protein gene. DNA fragments 738 bp were amplified by RT-PCR and these products were colned for sequence analysis. Based on the sequence analysis, this PCR product has 97% sequence homology to CTV (T-385) CP gene isolated from USA. RT-PCR assay for CTV detection was more sensitivity than ELISA assay which was done with anti-CTV CP antibody. This is the frist report about CTV identification in Cheju island Korea.

• The Plant Pathology Journal
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• v.26 no.3
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• pp.286-288
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• 2010

Plant tissue homogenization using a mortar or mechanical equipment has been the preferred method for obtaining high yields of total RNA; this method, however, is both time-consuming and expensive. Additionally, homogenization may generate excessive endogenous RNases, polyphenolics, and other substances that reduce the quality and quantity of RNA. In this study, we describe the microwave irradiation-assisted RNA extraction (MIRE) technique which, without tissue disruption and homogenization, allows for the cost-effective and rapid generation of intact RNA from apple cane shavings and the reliable detection of apple virus by RT-PCR.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.26-26
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• 2003

Hepatitis E virus (HEV) has been recognized as a major cause of enterically transmitted non-A, non-B hepatitis in many developing countries. The taxonomy of HEV is not clear and the virus remains unclassified. The objective of this study was to optimize conditions and procedures to detect swine HEV in formalin-fixed, paraffin-embedded tissues by nested RT-PCR and compare this detection method with in situ hybridization. (omitted)

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.149-154
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• 1988

Japanese Encephalitis Virus(JEV) can be detected conveniently by the use of biotinylated cDNA probe. To prepare biotinylated probe aminoallyl dUTP was first synthesized chemically to reverse transcribe the virial RNA. The allylamine-labeled cDNA was then converted to the biotin-cDNA by the reaction with an activated biotin ester, NHS-ACA-biotin. The JEV genomic RNA was hybridized to the biotinylated cDNA probe on nitrocellulose filter and visualized colorimetrically by streptavidin complexes with alkaline phosphatase polymer. Sensitivity of the detection system was determined by estimating the amount of the JEV genomic RNA through comparison with signals generated from the biotinylated and $^{32/P}$ -labeled probes. It was found that the biotin probe was as sensitive as $^{32/P}$ -cDNA probe which can detect 50pgs of the target RNA.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.2113-2116
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• 2003

이 논문에서는 리눅스 기반VDPM(Virus Detection Protection Management)시스템을 제안하고 개발한 응용SW로 감지, 차단 및 관리 방법을 제시한다. 제안된 LVPM시스템은 첫째특정탐색 및 전체탐색 알고리듬에 의하여 개발된 VDPM시스템은 신종 바이러스까지 탐지하는 모든 종류의 바이러스 탐지(VDPM_hawkeye) 모듈, Virus첵크하는 감시 및 Virus첵크후 친정, 제거하는 방지(VDPM_medic)모듈, DB를 update하는 기능을 가지는 관리(VDPM_manager)모듈과 원격 DB관리 및 Virus결과 보고 기능 (VDPM_reporter) 모듈로 되어 있으며 지능적인 Virus방지 시스템, 둘째 네트워크 패킷을 분석하여 네트워크를 통한 침 바이러스 탐지 및 대응 시스템과 셋째 네트워크 패킷을 분석하여 네트워치를 통한 네트워크형 악성 소프트웨어 대응 시스템을 포함한 바이러스 보호 통합 시스템을 구현하였다. 더불어 호스트와 네트웍기반의 통합적인 IDS가 방화벽(Firewall)시스템과 연동하여 IDS 단독 차단이 불가능한 공격을 차단하는 소프트웨어 시스템을 개발하는 것이며 관리자가 사용하기 쉬운 GUI환경으로 구현하였고 대규모 분산 네트워크 환경에서 효율적인 리눅스기반 침입탐지방지관리 솔루션을 제시한다.