• Journal of fish pathology
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• v.34 no.2
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• pp.133-140
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• 2021

With the recent isolation of a new betanodavirus in shellfish, Korean Shellfish Nervous Necrosis Virus (KSNNV), it has also been identified the reassortant KSNNV of two RNA segments, in which one segment is KSNNV genotype but the other one is known genotype. In this study, we confirmed that the ressortant KSNNVs obtained in previous screening study of our laboratory for betanodaviruses in shellfish were KS/RGNNV and RG/KSNNV type by performing two consecutive multiplex RT-PCR on each RNA1 and RNA2 segment (R1- and R2-discriminative multiplex two-step RT-PCR, respectively) to determine the genotype of each segment based on the size of amplicon. In the pathogenicity analysis, none of the reassortants induced specific external symptoms or mortality of VNN, but viruses of 2 × 10⁴~10⁵ copies/mg or more were detected at 14 days after injection (10⁷ copies/fish) in brain tissues of 4 species except for crucian carp and common carp among the 6 species of juvenile fish used. In addition, the histopathological features of weak but distinct vacuole formation were also found in the brain of these infected fish, but no difference was found between the two reassortants KS/RGNNV-KG and RG/KSNNV-CM.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.743-752
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• 1995

The study was carried out to characterize the properties of Korean isolates of EHV from aborted fetuses and determine envelope protein profiles. The results obtained were summarized as follows; 1. Two strains of EHV was isolated from 2 liver samples among 10 aborted fetuses from which the virus isolation was attempted. 2. Morphological and some enzymatic properties of the Korean isolates of EHV which was designated as $LC_1$ and $LC_2$ was identical to those of a reference strain of Australia-N of EHV-1. The Korean isolates of EHV could be propagated on ED cell culture and they formed typical plaques 1 to 2 days after infection in the ED cells from which typical cuboidal particles of 150~170 nm diameter herpesvirus were observed. The virus could be detected specifically from neucleus and cytoplasm of infected cells by flourescent antibody technique using FITC labelled anti-Aust IV(EHV-1) antiserum. The Korean isolates, $LC_1$ and $LC_2$ were specifically neutralized by anti Aust IV antiserum and reacted positively to CELISA. 3. The structural polypeptides of purified enveloped virions of $LC_1$ and $LC_2$ isolates of EHV were determined by SDS-polyacrylamide gel electrophoresis to identify the envelope glycoproteins. $LC_1$ and $LC_2$ strains revealed 14 glycoproteins ranging in molecular weight from 190 kD to 31 kD while 17 structural proteins of Aust IV(EHV-1), of which 14 were identical to those of $LC_1$ and $LC_2$, were identified. Upon immunoblotting by rabbit antiserum against EHV isolates and EHV-1(Aust IV), 4 immunogenic proteins of $LC_1$ and $LC_2$ were 135 kD, 88 kD, 64 kD and 59 kD, of which 135 kD, 88 kD and 64 kD proteins were also found in Aust IV(EHV-1).

• Korean Journal of Veterinary Research
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• v.55 no.3
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• pp.163-167
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• 2015

Canine parvovirus (CPV) is a major diarrhea-causing agent in puppies. Since CPV type 2 (CPV-2) emerged in 1978, new antigenic variants including CPV-2a, CPV-2b, and CPV-2c have been identified in many countries. Two puppies died suddenly at a veterinary clinic in Gyeonggi province, South Korea. Two viruses were isolated in A72 cells, confirmed as CPV strains based on a CPV rapid kit and an indirect fluorescence test and designated QIACP1403 and QIACP1404. The nucleotide sequences of complete VP2 genes of QIACP1403 and QIACP1404 were determined, and the corresponding amino acid sequences were deduced. Molecular analyses revealed that the QIACP1403 and QIACP1404 isolates were type CPV-2b. Several mutated amino acids were detected on VP2 gene residues of the two isolates. Phylogenetic analyses showed that the two isolates were most closely related to strain CPV-BM11, which was isolated from Chinese dogs in 2011. Our results suggest that these isolates may be a candidate for a vaccine to prevent CPV infection in dogs after conducting passages of the isolates in an in vitro culture system.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.1-4
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• 2003

Sericulture is a traditional agro-industry, which involves mulberry cultivation and silkworm rearing, has made great contributes to the human civilization. With the development of national economy and modem technology, mulberry and silkworm are being used to develop products with functionality besides the traditional cocoon production in China. In this paper, we brief the current developing situation of sericultural byproducts with functionality in the following aspects. (1) Functional products from silkworm larvae: silkworm powder, white muscardine silkworm, isolation and purification of anti-bacterial proteins from the larvae and production of medically valuable substances by Bombyx mori nuclear polyhedrosis virus (BmNPV) vector. (2) Utilization of silkworm feces: for pillow and for isolation of chlorophyll etc. (3) Production of valuable Chinese traditional medicine like Cordyceps sinensis with pupae, functional utilization of pupa protein and chitin. (4) Silk as additives to cosmetics, silk food and medical materials. (5) Functional utilization of mulberry: cultivation of edible fungus on mulberry shoots as medium, mulberry fruit drinks, mulberry tea, etc. The prospect of sericultural byproduct industry in China is also discussed.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.284-288
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• 2001

Respiratory viruses are one of the most infectious agent in human. Six different respiratory tract viruses were detected from Busan while working on the preventive surveillance in 1997-2000. The isolation rate from suspected specimens were 8.4%. Influenza virus A, B type, parainfluenza virus, adenovirus, mumps virus, and measles virus were examined from throat swabs, serum, and secretions of patients. Influenza A/Sydney/05/97(H3N2)-like, A/Johanesburg/33/94(H3N2)-like, A/Beijing/262/95(H1N1)-like and Influenza B/Beijing/262/95-like, B/Harbin/07/94-like, B/Guangdong/08/93-like were found. Adenovirus serotype 1, 2, 3 and 5 were detected, antibody of mumps both IgM and IgG were shown and outbreaks of measles were confirmed. Different antigenic types of influenza virus were detected every year, one outbreak of parainfluenza in 1999, mumps outbreak in 1999 and 2000, and incidence of measles in 2000 were noticeable. Monthly outbreaks were November through following March with influenza virus, January through June with adenovirus, February through May and December with mumps, April through August and November, December with measles, respectively. The size of isolated viruses were 130 nm with influenza virus B type, non-enveloped, icosahedron with 70 nm with adenovirus, 170 nm with mumps virus and 180 nm with parainfluenza virus in diameter, respectively.

• Korean Journal of Veterinary Research
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• v.30 no.1
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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.

• Korean Journal of Veterinary Service
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• v.14 no.2
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• pp.110-120
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• 1991

28 porcine enteroviruses were isolated from 86 pig-feces of 9 swine farms located in south region, Chung-buk, from March to September 1990. Physico-chemical properties and pathogenicity of isolates were investigated. Results obtained throughout experiments are summarized as follows. According to the age, weanlings(40-90 days), sucklings(10-30 days) and adult pigs(6 months over) showed the isolation rate of 67%. 8% and 4%, respectively. By physico-chemical tests, YD-90/22, YD-90/43 and YD-90/64 strains were found to be ether, chloroform and PH stable. Nucleic acid test suggests the virus to have a DNA genome. Most of the Isolates were not evident of hemagglutinin using erythrocytes from various mammalian & avian. 22 strains among the isolates were shown CPE type I and the remainders were CPE type II. 3 strains among isolates of CPE type I strains were neutralized with high titers to serotype 2 antiserum. In the study on virus growth curve in PK-l5 cells, YD-90/22, YD-90/43 and YD-90/64 strains showed the maximum infectivity titers($10^{6.0}-l0^{6.5} TCID({50}ml$) at 4days post inoculation(PI). When 30 day-old commercial piglets were inoculated only intraoral route with the YD-90/22 strain at $10^{6.0} TCID_{50}ml,$ piglets not showed the symptoms. But piglets inoculated by intramuscle route, intraoral and intramuscle route after pretreat with dexamethasone(2.5mg /kg) for 5 days were shown the symptoms of anorexia, diarrhea, pyrexia and ataxia at 4th-6th days PI. The viral reisolation in the virus-inoculated piglets was examined from feces. The viruses were recovered intermittently from 2nd to 16th day PI and at 4th-6th day PI, all piglets excreted viruses.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.463-469
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• 2003

Eight nursery to grower pigs exhibiting weight loss and sudden death were diagnosed as postweaning multisystemic wasting syndrome (PMWS) based on the results of gross findings, histopathology, immunohistochemistry, fluorescent antibody test, virus isolation, PCR, serology, and electron microscopy. Groosly, the pigs had a rough hair coats and were severely emaciated. And moot lymph nodes were pale and enlarged. Lungs were not fully collapsed and exhibited 10 to 40% pale red cranioventral consolidation. Histopathologically, typical lymphohistiocytic interstitial to bronchointerstitial pneumonia, chronic lymphadenitis, severe lymphoid depletion, and basophilic intracytoplasmic inclusions were noted in the most lymphoid tissues. Porcine circovirus panicles were observed in the inguinal lymph node of the pigs by electron microscopy. Porcine circovirus type 2 (PCV2) antigens or viral DNAs were detected in the lesions of all pigs using immunohistochemistry or PCR. Two PCV2 were isolated from a homogenate of pooled lung and lymph node in 2 of the 5 pigs. Additionally, antigens of porcine reproductive and respiratory syndrome virus (PRRSV) and Hemophilus (H.) parasuis were also detected by immunofluorescent antibody test. Serologically, 55% of randomly selected sows and fattening pigs was serum antibody positive to PCV2 by an indirect fluorescent antibody (IFA) test and approximately 18 % of animals in the herd were serologically pooitive by the ELISA kit for PRRSV. To our knowledge, this is the first report of PMWS co-infected with PCV-2, PRRS, and H. parasuis in Korea.

• Biomedical Science Letters
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• v.16 no.3
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• pp.201-206
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• 2010

In order to develop procedures for the rapid isolation of recombinant sugar transporter in functional form from away from the endogenous insect cell transporter, gene fusion techniques were exploited. Briefly, BamH1-digested human HepG2 type glucose transport protein cDNA was first cloned into a transfer vector pBlueBacHis, containing a tract of six histidine residues. Recombinant baculoviruses including the human cDNA were then generated by allelic exchange following transfection of insect cells with wild-type BaculoGold virus DNA and the recombinant transfer vector. Plaque assay was then performed to obtain and purify recombinant viruses expressing the human transport protein. All the cell samples that had been infected with viruses from the several blue plaques exhibited a positive reaction in the immnuassay, demonstrating expression of the glucose transport protein. In contrast, no color development in the immunoassay was observed for cells infected with the wild-type virus or no virus. Immunoblot analysis showed that a major immunoreactive band of apparent Mr 43,000~44,000 was evident in the lysate from cells infected with the recombinant baculovirus. Following expression of the recombinant fusion protein with the metal-binding domain and enterokinase cleavage site, the fusion protein was recovered by competition with imidizole using immobilized metal charged resin. The leader peptide was then removed from the fusion protein by cleavage with porcine enterokinase. Final separation of the recombinant protein of the interest was achieved by passage over $Ni^{2+}$-charged resin under binding conditions. The expressed transport protein bound cytochalasin B and demonstrated a functional similarity to its human counterpart.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.479-484
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• 1991

Encephalomyocarditis(EMC) virus was isolated from the mummified and stillborn pigs at a swine farm in Chonnam Province, experienced with EMC infection over the period Oct.~Dec. of 1989. In addition some cultural, serological properties of the isolates and experimental infections in the piglets were studied. The results obtained were as follows; 1. Two EMC virus strains with HA titers and CPE similar to EMC-ATCC were established in a baby hamster kidney (BHK)-21 cell line by inoculating homogenates of brain and heart of the 19 mummified or stillborn pigs and designated $K_3$ and $K_{11}$. 2. At the second BHK-21 cell line passage of the initial isolates CPE appeared after incubation for 16~18 hours, while at the fourth and fifth passage the highest titer of HA was recorded, titer of HA using rat and guinea pig erythrocytes. 3. One pig inoculated with the isolate $K_3$ showed dyspnea as clinical signs and died at the 10 days after inoculation at necropsy white necrotic foci were observed from the dead animal heart. 4. Although all the rest surviving pigs showed increases in antibody titer and body temperature of $40^{\circ}C$ above for the initial 2~4 days followed by the return to normal, there were no gross lesions when the animals were sacrificed at the 2 weeks after inoculation.