• Journal of Microbiology
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• v.38 no.4
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• pp.260-264
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• 2000

Reverse transcription (RT)-PCR and nested PCR methods (2-step PCR) were tested for their ability to detect marine birnavirus (MBV) in cultured rockfish, Sebastes schlegeli. One set of primers for RT-PCR was designed, based on a gene of infectious pancreatic necrosis virus (IPNV), and another set of primers for nested PCR was designed based on the VP2/NS junction region of MBV. This 2-step PCR method was specific for MBV and sensitivity was heightened when nested PCR was combined to RT-PCR. This 2-step PCR method was useful for detecting MBV not only in diseased fish, but also in asymptomatic fish. These results indicate that this 2-step PCR method is useful for detecting MBV in rockfish.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1055-1064
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• 2009

Enteroviruses were identified and characterized from patients with aseptic meningitis and other enterovirus-related diseases in Chungnam, Korea from 2005 to 2006. Enteroviruses were isolated from 79 of 519 cases (15.2%) in 2005, and 37 of 386 cases (9.6%) in 2006. Based on partial VP1 sequencing, a total of 116 enterovirus isolates were resolved into 13 types. Prevalent among the Chungnam isolates were echovirus 18 and coxsackievirus B5 in 2005, and echoviruses 5 and 25 in 2006. This is the first time echoviruses 5 and 18 have been identified in Korea since enterovirus surveillance began there in 1993. The temporal distribution of enterovirus epidemics in Chungnam showed a remarkable seasonal pattern, with cases occurring during most of the three months of the summer from June to August. The highest rate of enterovirus-positive cases occurred in patients less than 1 year of age. The ratio of male to female enterovirus-positive patients was approximately 1.8:1. Comparison of the VP1 amino acid sequences of the 15 coxsackievirus B5 isolates with reference strains revealed that all Chungnam isolates are substituted at positions 23 (V231), 19 (S19G), 75 (Y75F), and 95 (N95S). Upon comparing the nine ECV5 isolates with foreign strains, it was found that only the Chungnam isolates, with the exception of Kor06-ECV5-239cn, have P at position 153 and F at position 146. The three ECV9 isolates from 2006 show alterations at amino acids 36, 148, and 154 outside of the BC-loop and at position 84 in the BC-loop, whereas the seven isolates from 2005 and the other ECV9 strains in the database only show the alteration at position 84 (D, I, N, S). The five ECV25 isolates have an S residue at position 134, whereas most of the foreign strains have an N residue.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.81-90
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• 2015

Purpose: Group A rotavirus (RV) is most common etiologic agent of acute gastroenteritis (AGE) in children worldwide. Recently, vaccination has been introduced in several countries to reduce the disease burden caused by RV infections, but continuous surveillance of RV strains is necessary to detect the emergence of potential variants induced by vaccine-immune pressure. This study aimed to investigate the changing pattern of RV genotypes in children with AGE, following the introduction of vaccination in Korea. Methods: Genotyping of RVs by RT-PCR on the basis of VP7 and VP4 gene segment sequence was carried out on 201 rotavirus-positive stool samples, from children hospitalized with AGE between August 2009 and June 2013. We have directly sequenced PCR products and analyzed the phylogenetic tree. Results: The most prevalent G genotype was G9 (33.3%), followed by G1 (22.4%), G3 (15.9%), G2 (6.0%), G4 (3.0%), G10 (1.5%), and mixed G-type (15.4%), with some nontypeable cases (2.5%). The detected P genotypes were P[4] (45.3%), P[8] (43.8%), mixed P-type (10.4 %), and P[2] (0.5%). The G9P[4] genotype was predominantly observed in hospitalized cases in Seoul in 2010/2011, however G1P[8] has been re-emerged as the predominant genotype in the following season (P =0.004). Conclusions: It seems that the periodic fluctuation in predominance of the G1, G3, and G9 strains occurred in Korea during 2009-2013, following the introduction of RV vaccination.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.70-70
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• 2003

Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.300-307
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• 2006

In the present study, methods of the reverse transcription-polymerase chain reaction(RT-PCR) were evaluated for the rapid detection and differentiation of transmissible gastroenteritis virus(TGEV), porcine epidemic diarrhea virus(PEDV) and rotavirus in piglets suffering from diarrhea. For the purposes, the PCR conditions were first confirmed for the amplification of VP7 gene of rotavirus and N gene of TGEV and PEDV using each specific primers and their annealing temperature. Multiplex RT-PCR methods were further determined to distinguish these viral infections and the results are as follows. For the specific amplification of these viral genes, the reliable PCR condition was determined as 30 cycles of reaction consisting each 1 min of denature at $94^{\circ}C$, annealing at $42^{\circ}C$ and polymerization at $72^{\circ}C$ with 1.0 mM $MgCl_2$. It was able to differentiate these viral infections in the intestines and feces of piglets suffering from diarrhea by duplex PCR for TGEV and PEDV and single PCR for rotavirus with a primer-annealing temperature of $42^{\circ}C$. When the multiplex RT-PCR were undertaken for the field samples, 17 cases of PEDV and 5 cases of rotavirus infections were differential diagnosed in a total of 92 samples of intestines and feces of the piglets with diarrhea.

• Journal of fish pathology
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• v.22 no.3
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• pp.229-237
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• 2009

The causative agent for the tunic softness syndrome of the cultured ascidian Halocynthia roretzi from Jan 1999 to Feb 2009 was identified using virus isolation and polymerase chain reaction (PCR). The pathogenicity of the isolated virus MABV UR-1 strain was determined by experimental infection trials. The cytopathic effects was observed in CHSE-214 cell line at a level 5.1% (4/78) in normal ascidian and 1.8% in abnormal ascidian showing tunic softness syndrome signs. MABV gene was detected in 16.8% (18/107) of normal and 13.1% (5/38) of abnormal organisms by PCR. The ratio of MABV isolation and gene detection was similar level in normal and soft tunic diseased ascidian. Based on the VP2/NS junction region sequences, eight strains of virus isolated from ascidian, were included in the same genogroup with MABV which is originally isolated in wide ranges of marine fish and shellfish species. The UR-1 strain caused 60% mortality (36.5% mortality in control group) by immersion infection and 37% mortality (same mortality in control group) in injection infection indicating no significant differences in infected and control groups. These results suggest that ascidian can act as reservoir of the MABV, and this virus is not directly related with the ascidian mortality.

• Journal of Life Science
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• v.27 no.3
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• pp.275-282
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• 2017

Adenovirus (ADV) and human bocavirus (hBoV) cause acute respiratory tract infections, and are often associated with increased rates of hospitalization and death, particularly in infants and young children. The aim of this study was to analyze the clinical features and molecular phylogeny of ADV and hBoV isolated in Busan, from January 2011 to November 2013. In total, 3,230 specimens (throat swabs) were collected from patients with influenza-like illnesses and acute respiratory tract infections. Multiplex real-time RT-PCR was performed to detect eight respiratory viru [rhinovirus, adenovirus, respiratory syncytial virus, human coronavirus, human metapneumovirus, human bocavirus, parainfluenza virus and influenza virus] and detected 1,485(46.0%) cases. Among 1,485 positive specimens, 257(8.0%) cases were ADV and 68(2.1%) cases of hBoV. A significant clinical feature of ADV is fever and headache whereas hBoV is wheezing. Serotypic distributions of isolated ADV and hBoV were analyzed by sequencing of hexon and VP1/VP2 gene, respectively. ADV was identified seven different serotypes(1~6, 8), revealing a high similarity among the isolates (>97%). The predominant types of ADV were type 1 in 2011, type 3 and 4 in 2012, type 3 in 2013, respectively. ADV type 3 was major causative type during outbreaks in 2013. All of the hBoV was identified as hBoV type 1.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.588-591
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• 2018

Baculovirus was originally isolated from the alfalfa looper and contains a 134-kbp genome with 154 open reading frames (ORF). The major capsid protein VP39 together with some minor proteins forms the nucleocapsid ($21nm{\times}260nm$) that encloses the DNA with p6.9 protein. They are double-stranded, circular, supercoiled DNA molecules in a rod-shaped capsid. Wild-type baculoviruses exhibit both lytic and occluded life cycles that develop independently throughout the three phases of virus replication. Recombinant baculoviruses can transfer their vectors and express their recombinant proteins in a wide range of mammalian cell types. Especially, inclusion of a dominant selectable marker in these baculoviral vectors can express diverse recombinant genes in many cells. Baculoviral vectors were reconstructed with cytomegalovirus (CMV) promoter,uroplakin II promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) gene and so on. These reconstructed vectors were infected into various cell and cell lines. We performed transfection and expression of these recombinant vectors comparison with other control vectors. From this study, we knew that transfection and expression of these recombinant vectors have higher efficacy than any control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• Korean Journal of Veterinary Service
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• v.27 no.4
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• pp.355-369
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• 2004

The equine herpesvirus type 1 (EHV-1) immediate-early (IE) protein is a potent transactivator responsible for the activation of both early and late genes during the course of infection and is comprised of discrete functional domains that mediate its many functions. Interaction between trans activators such as the IE protein and various components of the RNA polymerase II transcription initiation machinery has been demonstrated to be critical for transactivation. In the present report, it is addressed the hypothesis that the IE protein interacts with various components of transcription machinery to mediate transactivation of target viral genes. In these studies, it is demonstrated that in vitro transcribed and translated IE protein interacts with TFIIB-agarose conjugate but not with TFIID-agarose conjugate. Additional immunoprecipitation studies using nuclear extracts derived from EHV-1 infected RK-13 cells confirmed that the IE protein interacts strongly with TFIIB, but fails to interact with TFIID. IR2, a truncated form of the IE protein lacking the potent transactivation domain and involved in the down-regulation of the IE gene, also interacted with TFIIB but not with TFIID. Studies were also performed to ascertain if particular TBP-associated factors (TAFs) could mediate IE or IR2 binding to TFIID. In vitro transcribed and translated TAF250 added to nuclear extracts generated from EHV-1 infected cells also failed to mediate an interaction between the IE protein or the IR2 protein and TFIID. This study demonstrated that the IE protein mediates transactivation of target viral genes by a mechanism that involves TFIIB. This is in contrast to mechanisms that have been proposed for both the herpes simplex virus ICP4 and VP16 protein which have been proposed to transactivate viral genes through interactions involving both TFIIB and TFIID. This study also intimates that IR2 mediate its repressive effects during the course of EHV-1 infection by a mechanism that involves sequestration of various transcription factors.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.511-515
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• 2007

White-spot syndrome virus (WSSV) is a devastating, infectious virus affecting shrimp. Although sensitive techniques involving PCR have been developed to assist farmers in screening shrimp (brood stock) for WSSV prior to stocking ponds, such practices have not yet been applied in Korea. Despite the rationality of implementing screening, there has been some doubt as to whether the stocking of WSSV-PCR-negative fly epidemiologically decreases white-spot disease outbreaks. Here, we report a retrospective analysis of data from shrimp farms in the western coast of Korea where WSSV-PCR-negative brood stocks were used to stock rearing ponds. A total of 366 shrimp from Heuksan Island were sampled for WSSV with PCR. Of the tested shrimp, 7.2% (28 brood stocks) were identified as WSSV positive; only WSSV-PCR-negative shrimp were used for brood stocks. Total unit production (final shrimp production/ the area of the ponds) was higher, at 1.96, in ponds where WSSV-PCR-negative shrimp were used, as compared with 1.02 in other ponds in Korea in 2004. This retrospective analysis of WSSV in Korea may be useful to the shrimp aquaculture industry, suggesting a testable hypothesis that may contribute to the eventual control of WSSV outbreaks.