• 대한수의학회지
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• 제57권1호
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• pp.37-42
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• 2017

Getah virus (GETV) infection causes sporadic outbreaks of mild febrile illness in horses and reproductive failure in pigs. In this study, we established a reverse transcription polymerase chain reaction (RT-PCR) method to detect GETV from suspected virus-infected samples. The reaction conditions were optimized and validated by using RNA extracted from GETV propagated in cell culture. A GETV-specific GED4 primer set was designed and used to amplify a 177 bp DNA fragment from a highly conserved region of the E1 glycoprotein gene in the GETV genome. RT-PCR performed with this primer set revealed high sensitivity and specificity. In the sensitivity test, the GED4 primer set detected GETV RNA at the level of $10^{2.0}\;TCID_{50}/mL$. In the specificity test, the GED4 primer set amplified only a single band of PCR product on the GETV RNA template, without non-specific amplification, and exhibited no cross-reactivity with other viral RNAs. These results suggest that this newly established RT-PCR method is useful for accurate identification of GETV infection in animals.

• 한국동물위생학회지
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• 제36권2호
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• pp.87-93
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• 2013

This study was conducted to investigate the antimicrobial, antivirus properties of Saururus chinensis extracts. The n-hexane extracts from Saururus chinensis showed the active antimicrobial activity against gram-positive bacteria. Minimum inhibitory concentration (MIC) of Saururus chiensis n-hexane extracts was 1.25 mg/ml against B. subtilis and 2.5 mg/ml against S. aureus. The cytotoxicity effects on MDBK (Madin-Darby bovine kidney) cell were observed at the various n-hexane extract concentrations. In $TCID_{50}$ assay, 0.6 mg/ml of n-hexane extracts decreased BVD (bovine viral diarrhea) virus by 1.4 log, whereas other extracts did not show antiviral activity. In this study, The results suggested that n-hexane extracts and fractions of Saururus chinensis can be a candidate materal of feed additive to chemical antibiotics and antivirus substances.

• Journal of Microbiology
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• 제39권1호
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• pp.67-73
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• 2001

A validation study was conducted to evaluate the efficacy and mechanism of the cryo-precipitation, monoclonal anti-FVIIIc antibody (mAb) chromatography, Q-Sepharose chromatography, and lyophilization steps involved in the manufacture of high purity factor VIII (GreenMono) from human plasma, in the removal and/or inactivation of hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and subjected to scale-down processes mimicking the manufacture of the high purity factor VIII concentrate. Samples were collected at each step and immediately titrated using a 50% tissue culture infectious dose (TCID$\_$50/) and then the virus reduction factors were evaluated. HAV was effectively partitioned from factor VⅢ during cryo-precipitation with the log reduction factor of 3.2. The mAb chromatography was the most effective step far removal of HAV with the log reduction factor of $\geq$4.3. HAV infectivity was not detected in the fraction of factor VⅢ, while most of HAV infectivity was recovered in the fractions of flow through and wash during mAb chromatography. Q-Sepharose chromatography showed the lowest efficacy for partitioning HAV with the log reduction factor of 0.7. Lyophilization was an effective step in inactivating HAV with the log reduction factor of 2.3. The cumulative lag reduction factor, $\geq$10.5, achieved for tile entire manufacturing process was several magnitudes greater than the potential HAV load of current plasma pools.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.858-864
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• 2000

The purpose of the present study was to examine the efficacy and mechanism of the fraction IV cold ethanol fractionation and pasteurization ($60^{\circ}C$ heat treatment for 10h) steps, involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of blood-born viruses. A variety of experimental model viruses for human pathogenic viruses, including the Bovine viral diarrhoea virus (BVDV), Bovine herpes virus (BHV), Murine encephalomyocarditis virus (EMCV), and Porcine parvovirus (PPV), were selected for this study. Samples from the relevant stages of the production process were spiked with the viruses, and the amount of virus in each fraction was then quantified using a 50% tissue culture infectious dose ($TCID_{50}$). The mechanism of reduction for the enveloped viruses (BHV and BVDV) during fraction IV fractionation was inactivation rather than partitioning, however, it was partitioning in the case of the non-enveloped viruses (EMCV and PPV). The log reduction factors achieved during fraction IV fractionation were ${\geq}6.9$ BHV, $\geq5.2$ for BBDV, 4.9 for EMC, and 4.0 for PPV. Pasteurization was found to be a robust and effective step in inactivating the enveloped viruses as well as EMCV. The log reduction factors achieved during pasteurization were $\geq7.0$ for BHV, $\geq6.1$ for BVDV, $\geq6.3$ for EMCV, and 1.7 for PPV. These results indicate that the production process for albumin has sufficient virus-reducing capacity to achieve a high margin for virus safety.

• 생명과학회지
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• 제19권7호
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• pp.928-933
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• 2009

노로바이러스는 인간에게 급성위장염을 일으키는 식중독 바이러스로, 최근 전세계적으로 노로바이러스 식중독 사고가 증가하고 있다. 따라서 본 연구에서는 다양한 생리활성 작용이 있다고 알려진 향신료, 차(茶), 식물성 한약재등 11종의 천연물질을 대상으로 노로바이러스의 대체모델인 feline calicivirus (FCV 에 대한 항바이러스 활성을 조사하였다. 각 추출물에 대한 항바이러스 활성은 end point dilution assay 방법인 50% tissue culture infectious dose ($TCID_{50}$)으로 바이러스 감염가를 측정하였다. 녹차(Camellia sinensis L.) 추출물의 경우 3.13 mg/ml의 농도에서 1 시간만에 FCV가 완전히 불활성화 되었으며, 홍화씨 (Carthamus tinctorius L.) 추출물은 6.25 mg/ml의 농도에서 5시간 만에 바이러스가 불활성화 되어 녹차추출물이 FCV에 대한 항바이러스 활성이 가장 뛰어난 것으로 조사되었으며, 농도 및 반응시간에 유의적으로 항바이러스 활성을 나타내는 것으로 관찰되었다. 녹차 및 홍화씨 추출물 등과 같은 천연식물 자원을 이용하여 FCV에 대한 항바이러스 활성을 조사한 결과는 궁극적으로는 노로바이러스에 의한 식중독 저감을 위한 기초자료에 이용될 수 있을 것으로 기대된다.

• 대한수의학회지
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• 제61권2호
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• pp.13.1-13.8
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• 2021

Mammalian reovirus (MRV) causes respiratory and intestinal disease in mammals. Although MRV isolates have been reported to circulate in several animals, there are no reports on Korean MRV isolates from wildlife. We investigated the biological and molecular characteristics of Korean MRV isolates based on the nucleotide sequence of the segment 1 gene. In total, 144 swabs from wild animals were prepared for virus isolation. Based on virus isolation with specific cytopathic effects, indirect fluorescence assays, electron microscopy, and reverse transcription-polymerase chain reaction, only one isolate was confirmed to be MRV from a Korean roe deer (Capreolus pygargus). The isolate exhibited a hemagglutination activity level of 16 units with pig erythrocytes and had a maximum viral titer of 10^5.7 50% tissue culture infectious dose (TCID₅₀)/mL in Vero cells at 5 days after inoculation. The nucleotide and amino-acid sequences of the partial segment S1 of the MReo2045 isolate were determined and compared with those of other MRV strains. The MReo2045 isolate had nucleotide sequences similar to MRV-3 and was most similar (96.1%) to the T3/Bat/Germany/342/08 strain, which was isolated in Germany in 2008. The MReo2045 isolate will be useful as an antigen for sero-epidemiological studies and developing diagnostic tools.

• 한국임상수의학회지
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• 제29권5호
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• pp.377-383
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• 2012

송아지 설사병은 국내 축산산업에 큰 피해를 주는 중요한 질병이다. 다양한 감염성 원인체들이 송아지 설사병에 관련될 수가 있기 때문에 효과적인 치료를 위해서는 신속한 감별진단이 필수적이다. 따라서 소설사병 바이러스(BVDV), 소 코로나바이러스(BCoV), A형 소 로타바이러스(BRV), 살모넬라, $K99^+$ 대장균, Cryptosporidium parvum등의 6개의 주요 병원체들을 동시에 검출하는 두 개의 multiplex real-time PCR으로 구성된 PCR 패널을 개발하여 국내 농가에서 전북대학교 동물질병진단센터로 접수된 97개의 설사 분변을 검사하였다. 또한 현미경 검사법을 이용하여 97개의 분변에서 Coccidium 충란을 검사하였다. 개발된 multiplex PCR의 민감도는 BVDV, BCoV와 BRV의 경우는 0.1 $TCID_{50}$, $K99^+$ 대장균은 5 CFU, Salmonella는 0.5 CFU, Cryptosporidium는 50 oocysts로 측정되었다. 또한 multiplex PCR의 증폭효율은 병원체에 따라0.97에서 0.99였다. 국내에서 접수된97개의 분변 중 36개의 분변은 multiplex PCR에 의해 최소 하나의 병원체에 대해 양성으로 판정되었고, 6개의 샘플은 2개의 병원체에 동시에 양성반응을 보였다. 또한 1달 이상 연령의 송아지 분변48개에서는 Coccidium 충란이 발견되었다. 결과적으로, 새로이 개발된 multiplex real-time PCR은 BVDV, BCoV, BRV, $K99^+$ 대장균, Salmonella와 Cryptosporidium과 관련된 송아지 설사병을 신속하고 정확하게 진단할 수 있는 유용한 검사법이 될 수 있을 것으로 기대되며 향후 Coccidium까지 검출할 수 있는 동시 진단법이 개발될 필요가 있을 것으로 생각된다.

• 대한수의학회지
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• 제49권3호
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• pp.201-205
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• 2009

In this study, we evaluated the stability and potency of live attenuated rinderpest vaccines of lapinized-avianized tissue culture strain origin, which had been produced annually from 2005 to 2008. When immune responses to the vaccines were evaluated using two Holstein calves weighing 100~150 kg, neutralizing antibody titer of 1 : 16 was induced at 21 days post vaccination. When calves were also inoculated with vaccines lots that had been stored for 39 months at ${4^{\circ}C}$, same level of antibody titer was observed. Using the virus titer test, we found that all batches of the vaccine that had been kept for 3, 10, 15, 22, 27, 34, 39, and 45 months showed no significant loss of titers, and fulfilled the requirement necessary ($\geq$ 3 $logTCID_50$) to be used as the national rinderpest vaccine reserve in Korea. In this study, we demonstrated that stability and potency of the rinderpest vaccines were maintained over three years when kept at ${4^{\circ}C}$ storage. This indicates that it maybe feasible to extend the expiration period of this vaccine from one year to three years.

• 대한수의학회지
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• 제28권1호
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• pp.105-110
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• 1988

To establish a laboratory animal model for study on development of diagnostic methods for infectious bovine rhinotracheitis virus(IBRV), experimental infection of the virus to rabbits immunosuppressed with dexamethasone(DX) were carried out. Results obtained throughout the experiments were as follows. When lymphocyte activity was measured by lymphocyte transformation to phytohaemagglutinin in parallel with total and differential leucocyte counting, both groups treated with 2.0mg DX once and 1.0mg DX daily showed marked immunosuppression between 5 to 72 hrs. after administration. The degree of suppression of lymphocyte activities was more remarkable in the latter group. IBRV PQ7 strain at $10^{7.5}\;TCID_{50}/0.2ml$ was inoculated into conjunctival sacs of rabbits immunosuppressed with DX and non-treated. During 3 weeks observation, the immunosuppressed groups revealed mild conjunctivitis, viremia and virus recovery by 33.3 to 100%, whereas the DX nontreated group showed viremia and virus recovery with no clinical conjunctivitis by one of three rabbits(33.3%). In conclusion, it was indicated that experimental infection of IBRV PQ7 strain to rabbit was limited in prerequisite to immunologic modification by administration of immunosuppressive drugs.

• 대한수의학회지
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• 제30권1호
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• pp.93-102
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• 1990

Thirty-day-old piglets were intranasally or subcutaneously inoculated with 2ml of Aujeszky's disease virus, NYJ-1 strain, at the titer of $10^{6.75}$ $TCID_{50}/0.1ml$, that was isolated from the diseased piglets in Korea, and histopathological studies were performed to elucidate the pathognomonic characters of the isolate. Results obtained through the experiments were as follows: 1. Major clinical signs on the 2nd and 3rd days post inoculation (p.i.) were fever, anorexia and dyspnea. On the 6th and 7th days p.i., nervous signs, severe dyspnea and salivation were observed in the group of intranasal inoculation, and one out of 3 piglets in this group died on the 7th day p.i.. General signs were more severe in the group of intranasal inoculation than the group of subcntaneous injection. Between the 8th and l0th days p.i., the signs subsided and the piglets were completely recovered from the illness. 2. Hematologically, most of the inoculated pigs showed a mild lymphocytopenia on the 5th and 6th days p.i.. 3. By necropsy, swelling and hemorrhagic lesions were observed in tonsil, central nervous system and lung. No specific changes were grossly found in other parenchymatous organs. 4. In histopathological study, degeneration and necrosis of nervous cells, non-suppurative meningoencephalitis, diffuse or focal gliosis, perivascular cutting and degeneration of ganglion cells were observed in central nervous system, and swelling and hemorrhagic changes were shown in the tissues of liver, lung and lymph nodes. 5. By indirect immunofluorescence antibody assay using ADV-monoclonal antibody, specific ADV antigens were detected in the tissues of tonsil, brain and spleen of the succumbed piglet. However, in the experimentally slaughtered piglets, the specific reactions were noted only in the tonsils.