• 대한수의학회지
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• 제32권4호
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• pp.585-595
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• 1992

We have investigated the characteristics of encephalomyocarditis(EMC) virus isolated in Korea. The CPE, buoyant density, polypeptide profile and the size of RNA of EMC virus were examined. The granulation, pyknosis and necrosis were observed from 30 to 48 hour's post inoculation of the virus into baby hamster kidney and lung cells. The buoyant density was 1.30 and $1.35g/m{\ell}$. Three different polypeptides, 26Kd, 32Kd, and 34Kd in size, were observed and the size of viral RNA was 7.7Kb.

• 대한수의사회지
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• 제28권12호
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• pp.726-735
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• 1992

For the pathologic study of experimental encephalomyocarditis(EMC) infection in piglets by the isolates EMC $K_3$ and $K_11$ isolated from Korea,12 piglets aged 35 days divided into three groups, each of which was infected with the t

• 대한수의학회지
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• 제34권2호
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• pp.349-359
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• 1994

To elucidate pathogenicity to hamster of encephalomyocarditis virus $K_3$ strain that was isolated in Korea from the swine with reproductive failures, adult male syrian hamsters were experimentally infected intraperitoneally with the virus at $10^{7.0}\;TCID_{50}/0.1ml$ and pathological and immunohistochemical studies were performed. The results obtained through the experiment were as follows. 1. Clinical signs such as depression, unkempt hair and bilateral parlysis of hind limbs were observed. 2. At necropsy, mild congestion was observed in the cerebrum, liver, kidney and lung, and atrophy was evident in testis. 3. In microscopic observation, degeneration and necrosis of the nervous cells and perivascular mononuclear cell infiltration were manifested in central nerve system, and various degrees of degeneration and necrosis of parenchymal cells were detected in pancreas, lacrimal gland, liver, kidney and testis. 4. In immunohistochemical observation, strong positive reactions were observed in degenerated parenchymal cell of testis, and weak positive reactions, in hepatocytes.

• 대한수의학회지
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• 제33권2호
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• pp.301-308
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• 1993

Three or 7day old piglets were infected experimentally with different encephalomyocarditis virus isolates to detect the viral antigen by the immunoperoxidase technique and to observe strain difference in their pathogenecity in newborn pigs by comparing clinical signs and pathologic lesions. Clinical signs of the infected pigs were different depending on the virus strain, pig age and infection route. Encephalomyocarditis virus(EMCV) NVSL-PR isolate was more pathogenic than MN-25 and MN-30 isolate. Three day old piglets showed more severe illness than 7 day old piglets. Predominant clinical signs were sudden death without noticeable clinical signs and dyspnea manifested as heavy abdominal breathing. Contact-infection from infected piglets to controls was observed in the oro-nasally infected group but not the intramuscular group. Common necropsy findings of dead piglets in both age groups infected with MN-25 and NVSL-PR were accumulation of excessive fluid in the body cavities and mild to diffuse necrotic areas observed in the hearts and occasionally in the livers. Microscopically, myocarditis with inflammatory cell infiltration, necrosis of the myocardial muscle fibers and occasional mineralization were observed along with interstitial pneumonia and centrolobular necrosis in the liver. Using an immunoperoxidase technique, viral antigen was detected in myocardial muscle fibers of piglets infected with EMCV.

• 대한수의학회지
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• 제30권4호
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• pp.441-446
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• 1990

Encephalomyocarditis virus infection in pigs, characterized by severe reproductive failure in sows and sudden death in less than 7 day-old-piglets, a period of several months from October to December of 1989, in Korea was occurred. The most outstanding gross lesions at necropsy were found in the heart which were consisted of pale, yellow brown necrotic foci of varying size in myocardium. In some cases, pulmonary edema and liver congestion were observed. Histopathology of the heart revealed the interstitial myocarditis, endocarditis and epicarditis with lymphocytic, plasmacytic and macrophage cell infiltration and, in some cases, calcification of the necrotic myocardial muscle fibers. In some cases of brain, the perivascular cuffing and glial nodules were observed. In the liver and the lacrimal gland varying degrees of multifocal necrosis were seen. The virus was isolated from the heart and the brain in a stillborn piglet and a mummified fetus. This outbreak represents the first case of encephalomyocarditis virus infection of pigs in Korea.

• 한국동물위생학회지
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• 제17권1호
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• pp.67-80
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• 1994

8-10 week old ICR mice were infected intracerebrally and intraperitoneally with different encephalomyocarditis virus(K$_3$, $K_{11}$, ATT-VR 129) to observe histopathological and immunohistochemical change. Results obtained throuh the experiments were summarized as follows : 1. No differences in clinical signs by the virus strains and the inoculation routes were found. Mice infected with EMCV showed clinical signs after 3 days of inoculation. Main clinical signs were tremors, convulsions, circling movement, and uni or bilateral hindleg paralysis followed by death on the 3-8 days. In general, most of the infected animals died or recovered closely on the 8th day of postinoculation. 2. At necropsy, petechial and ecchymotic hemorrhages in lung were observed and no specific findings in other were observed. 3. In histopathological observation, neuroal cell degeneration perivascular mononucear cell in-filtration gliosis were appeared in central nervous system. Myocarditis with myocardial degeneration and necrosis, calcification were observed along with acinar cell necrosis of exocrine glands in pancreas, severe glomerulonephritis in kidney. Also, focal necrosis of hepatocytes and interstitial pneymonia hyperemia, hemorrhages in lungs were observed. 4. By immunohistochemical staining using ABCIT method, the positive cells were recognized in intracytoplasm of acinar cell in pancreas and intracytoplasm of neuronal cells in cerebrum.

• 미생물학회지
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• 제39권4호
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• pp.242-247
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• 2003

Murine encephalomyocarditis virus (EMCV)는 혈장유래의약품의 바이러스 안전성 검증을 위해 hepatitis A virus (HAV)의 모델 바이러스로 사용되어왔다. 근래에 혈액응고인자제제에 의한 HAV 감염사례가 보고되면서 혈장유래의약품의 HAV 안전성 검증에 대한 국제적인 규제가 강화되어가고 있다. 본 연구에서는 HAV와 EMCV의 바이러스 불활화 공정에 대한 민감도를 평가하여, 혈장유래의약품 제조공정에서 HAV 불활화 공정의 검증법을 표준화하고자 하였다. HAV와 EMCV의 바이러스 불활화 공정에 대한 민감도를 평가한 결과 HAV가 60$^{\circ}C$ 열처리, low pH 처리(pH 3.9), 0.1 M NaOH 처리, 동결건조 공정 모두에서 EMCV보다 더 저항성이 큰 것을 확인할 수 있었다. EMCV는 특히 열처리와 0.1 NaOH 처리에 민감하게 불활화 되었지만, HAV는 큰 저항성을 나타내었다. 열처리의 경우 2시간 안에 EMCV는 검출한계 이하로 감소하였지만, HAV는 5시간 후에 검출한계 이하로 감소하였다. 0.1 M NaOH 처리시 EMCV는 15분 안에 검출한계 이하로 감소하였지만, HAV는 120분 정도의 처리에도 감염성 바이러스가 검출되었다. pH 3.9에서 25$^{\circ}C$로 14일 동안 항온하였을 때 HAV와 EMCV의 log 감소인수는 각각 1.63, 3.84이었다. 또한 혈액응고 8인자 제조공정의 동결건조 과정에서 HAV와 EMCV의 log 감소인수는 각각 1.21, 4.57이었다. 이와 같은 결과는 혈장유래의약품 제조공정의 HAV 불활화 또는 제거 검증시 모델 바이러스로 사용된 EMCV의 검증 결과를 해석함에 있어 보다 신중함을 가져야 한다는 것을 보여준다. 또한 보다 정확한 HAV검증 결과를 얻고자 한다면 모델 바이러스인 EMCV 보다 HAV를 사용하는 것이 보다 더 타당하다고 사료된다.

• 약학회지
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• 제43권4호
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• pp.464-468
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• 1999

In order to find less toxic antiviral agents from basidiomycetes, EA, the water soluble substance, was isolated from the carpophores of Elfvingia applanata (Pers.) Karst. Anti-encephalomyocarditis (EMC) virus activity of EA was examined in Vero cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha and gamma were examined on the multiplication of EMC virus. EA exhibited a concentration-dependent reduction in the plaque formation of EMC virus with 50% effective concentration ($EC_{50}$) of 2.12 mg/ml. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. The combination of EA with IFN alpha showed potent synergism with CI values of 0.40~0.60 for 50%, 70% and 90% effective levels, but that with IFN gamma showed antagonism with CI values of 2.16~2.83.

• 대한수의학회지
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• 제50권3호
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• pp.221-229
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• 2010

Encephalomyocarditis virus (EMCV) belongs to the genus Cardiovirus within the family Picornaviridae. EMCV has been recognized either as a cause of mortality in young pigs, due to acute myocarditis, or of reproductive failure in sows. An EMCV K3 strain was isolated from the heart and brain in a mummified and aborted swine fetus in 1989. For the molecular characterization of the poly(C)-tract of EMCV Korean isolates, K3 strain, viral RNA was extracted and digested with RNase T1, and analyzed the length of the poly(C)-tract by polyacrylamide gel electrophoresis. The poly(C) regions also were amplified by RT-PCR and sequenced. The present study shows that K3 strain of EMCV had a short polymorphic poly(C) tracts (5 to 30 C's) with sequences consisting of $C_9$, $C_{10}$, $C_{13}$, $C_{14}$, $C_{16}$, $C_{20}$, $CUC_{11}$, $C_8UCUC_3UC_{10}$, $C_9UCUC_3UC_{10}$, $C_{10}UCUC_3UC_{10}$, etc. These polymorphism of poly(C)-tracts of EMCV K3 strain implies the historical information of in vivo and/or in vitro passage.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1570-1576
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• 2006

An encephalomyocarditis virus (EMCV-CBNU) was isolated from an aborted swine fetus in October 2005. To investigate the genetic origin and virulence of the EMCV-CBNU strain, we determined the complete sequence of the virus and tested its virulence in mice. Genetic characterization revealed that the RNA genome was composed of 7,713 nucleotides with a single open reading frame (2,292 amino acids), coding 12 proteins. The EMCV-CBNU had the shortest poly(C) tract, consisting of 10 C's ($C_{10}$), compared with all the other EMCV strains reported in GenBank. Amino acid and phylogenetic analyses showed that EMCV-CBNU had the highest genetic identity with strain 2887A (99.7%), which was originally isolated from a fetus in a pig breeding farm that had a history of reproductive failure. Because rodents are the natural host of EMCV, we investigated the virulence of EMCV-CBNU in mice. Surprisingly, all mice inoculated with more than $1{\times}10^2\;TCID_{50}/0.1ml$ of EMCV-CBNU showed symptoms of hind limb paralysis and eventually died during 3 and 8 days postinoculation (DPI). Furthermore, when we inoculated the virus into pregnant mice, all dams and their fetuses died in 6 DPI. This is the first report on a full genomic analysis of swine EMCV in Korea, which exhibits high virulence in mice.