• 한국가금학회지
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• 제12권2호
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• pp.135-143
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• 1985

관절염(또는 건초담), 발육부전증을 보이는 12주령 이하의 브로일러 종계와 브로일러에서 8주의 바이러스를 분리하여 avian reovirus로 동정하였다. 부리된 reovirus는 전자현미경에서 이중막을 갖는 구형으로 virion의 직경은 81nm였으며 한천겔침강반응에서 기지의 reovirus(S-1133 주) 및 항혈청(항 S-1133주 및 R-1주)과 반응하였다. 분리된 revirus는 혈구응집능력이 없었으며 chloroform, IUdR 및 열처리(56$^{\circ}C$, 30분)에 강한 저항성을 나타내었다. Reovirus의 감염성 측정시 계 태아섬유아세포 및 가세포배양과 Vero cell 배양에서 세포분주와 동시에 바이러스를 접종하거나 단층세포가 형성된 후접종하거나 간에 별다른 차이없이 감염 4-5일후에 end point에 도달되었다. 분리된 reovirus를 계태아간세포배양에 5-10대 계대배양한 후 $10^{5.0}$ TCI $D_{50}$의 바이러스를 10일령 발육계란의 장요막상에 접종하였을 때 평균치사시간이 국내분리주는 54-59시간인데 반하여 S-1133주는 73시간으로 약간 길었다.

• 한국양식학회지
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• 제10권2호
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• pp.171-178
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• 1997

Infectious pancreatic necrosis virus (IPNV)는 치어에 감염되어 치명적인 질병을 유발하는, 양식산업에 있어 중요한 어류 병원체이다. 본 연구에서는 IPNV를 신속, 정확하게 진단하는 방법을 개발하고자 IPNV의 항원성 단백질인 VP2 유전자 부분에서 선택한 primers를 이용하여 역전사-중합효소연쇄반응법(Reverse Transcription-Polymerase Chain Reaction, RT-PCR)을 실시하였다. RT-PCR 증폭법으로 순수분리도니 IPNV dsRNA 40 ng 정도의 적은 양도 확인 할 수 있었으며, IHNV와 같은 다른 어류 병원체의 게놈을 RT-PCR templates로 사용하였을 경우는 어떠한 PCR 산물도 검출되지 않는 특이성을 보였다. 특히 유전자의 분리없이 조직 그 자체를 대상으로 RT-PCR을 행하는 in situ RT-PCR 방법으로 IPNV가 감염된 넙치 (Paralichthy olivaceus) 치어의 조직에서 IPNV 감염을 신속하게 확인할 수 있었다. 따라서 RT-PCR 및 in situ RT-PCR 방법은 IPNV를 신속, 정확하게 진단하는데 활용될 수 있을 것으로 생각된다.

• 대한수의학회지
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• 제25권2호
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• pp.155-165
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• 1985

Effects of binary ethylenimine (BEI) treatment on the inactivation of infectivity and hemagglutinin of Newcastle disease virus (NDV) were studied in comparison with those of formalin treatment. Immune responses of chickens vaccinated with BEI-inactivated NDV vaccines were also investigated. The results were summarized as followings; 1. Complete loss of infectivity of NDV (Bl) was observed at 3, 7, and 24 hours after the treatment at $37^{\circ}C$ with BEI concentrations of 0.01M, 0.005M and 0.001M, respectively. 2. The hemagglutinin activity of NDV (Bl) remained constant when treated with 0.01M BEI at $37^{\circ}C$. However, it gradually decreased when treated with 0.1% or 0.2% formalin at $37^{\circ}C$. 3. When 4-week-old chickens were vaccinated with NDV vaccines prepared from Bl or Miyadera strains of NDV, inactivated with 0.1M BEI and adsorbed to aluminium hydroxide gel, favorable immune responses were observed throughout the 8 weeks of observation period. 4. When these chickens were revaccinated at 8 weeks after the first vaccination, strong anamnestic responses were evoked and the immunity maintained for 4 weeks of the observation. Though slightly bettor immune responses were observed after primary vaccination in chickens vaccinated with Bl vaccine compared with those vaccinated with Miyadera vaccine, the differences were not significant. 5. On the electron microscopy, BEI (0.01M) gave least effect to the envelope as well as capsid of NDV.

• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.356-363
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• 2016

Human papillomavirus (HPV), a non-enveloped, double-stranded DNA tumor virus, is a primary etiological agent of cervical cancer development. As a potential tool for prophylactic vaccination, the development of virus-like particles (VLPs) containing the HPV16 L1 capsid protein is highly desired. In this study, we developed a high-level expression system of the HPV16 L1 in Escherichia coli for the purpose of VLP development. The native gene of HPV16 L1 has many rare codons that cause the early termination of translation and result in the production of truncated forms. First, we optimized the codon of the HPV16 L1 gene to the preferable codons of E. coli, and we succeeded in producing the full-size HPV16 L1 protein without early termination. Next, to find the best host for the production of HPV16 L1, we examined a total of eight E. coli strains, and E. coli BL21(DE3) with the highest yield among the strains was selected. With the selected host-vector system, we did a fed-batch cultivation in a lab-scale bioreactor. Two different feeding solutions (complex and defined feeding solutions) were examined and, when the complex feeding solution was used, a 6-fold higher production yield (4.6 g/l) was obtained compared with that with the defined feeding solution.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.721-728
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• 2012

The human papillomavirus (HPV) is the main cause of cervical cancer in developing countries. Rapid diagnosis and initiation of treatment of the HPV infection are critical. Various methods have been employed to reduce the immunogenicity of antibodies targeting HPV serotypes. Nanobodies are the smallest fragments of naturally occurring single-domain antibodies with their antigen-binding site compromised into a single domain. Nanobodies have remarkable properties such as high stability, solubility, and high homology to the human VH3 domain. In this study, a phagemid library was employed to enrich for nanobodies against the L1 protein of the human papilloma virus. Binding reactivity of the selected clones was evaluated using phage enzyme-linked immunosorbent assay (phage-ELISA). Finally, two nanobodies (sm5 and sm8) with the best reactivity against the Gardasil vaccine and the purified HPV-16 L1 protein were expressed and purified using a $Ni^+$-NTA column. The accuracy of expression and purification of the nanobodies was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting assays. In vitro studies demonstrated that neutralization was achieved by the selected nanobodies. The ease of generation and unique features of these molecules make nanobodies promising molecules for the new generation of HPV diagnosis and therapy.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.2012-2018
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• 2016

Coxsackievirus B3 (CVB3) is the main cause of acute myocarditis and dilated cardiomyopathy. Plant extracts are considered as useful materials to develop new antiviral drugs. We had previously selected candidate plant extracts, which showed anti-inflammatory effects. We examined the antiviral effects by using a HeLa cell survival assay. Among these extracts, we chose the Amomi Cardamomi (Amomi) extract, which showed strong antiviral effect and preserved cell survival in CVB3 infection. We investigated the mechanisms underlying the ability of Amomi extract to inhibit CVB3 infection and replication. HeLa cells were infected by CVB3 with or without Amomi extract. Erk and Akt activities, and their correlation with virus replication were observed. Live virus titers in cell supernatants and viral positive- and negative-strand RNA amplification were measured. Amomi extract significantly increased HeLa cell survival in different concentrations ($100-10{\mu}g/ml$). CVB3 capsid protein VP1 expression (76%) and viral protease 2A-induced eIF4G1 cleavage (70%) were significantly decreased in Amomi extract ($100{\mu}g/ml$) treated cells. The levels of positive- (20%) and negative-strand (80%) RNA were dramatically decreased compared with the control, as revealed by reverse transcription-PCR. In addition, Amomi extract improved mice survival (51% vs 26%) and dramatically reduced heart inflammation in a CVB3-induced myocarditis mouse model. These results suggested that Amomi extract significantly inhibited Enterovirus replication and myocarditis damage. Amomi may be developed as a therapeutic drug for Enterovirus.

• 수산해양교육연구
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• 제27권4호
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• pp.1184-1193
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• 2015

Monitoring for megalocytivirus infection was conducted for ten months from March to December in 2013 in 15 aquatic farms culturing, red sea bream, rock bream, rock fish and black sea bream around Tongyoung coastal area in Korea, to assess spatial and temporal variability of detection prevalence, and to explore possible links with seawater temperature. In nested-PCR targeted major capsid protein (MCP) gene, asymptomatic megalocytivirus infection was detected in the externally healthy farmed fish with a significant prevalence in range from 0 to 58.3% for ten months. Higher prevalence of megalocytivirus (46.7% - 57.1%) was observed in high water temperature season from September to November than that in other months with lower prevalence of 0.0% to 20.0%. Even though an acute infection of megalocytivirus was occurred in rock bream (positive in the first PCR) with high mortality in one of fifteen farms, there was no expansion or transmission of the disease to the rock fish and red sea bream culturing in net cage just proximal to the rock bream cage in which disease outbreaked. Nucleotide sequence analysis of the cloned MCP gene isolated asymptomatically infected rock fish revealed that the megalocytivirus in this study was clustered together with the rock bream iridovirus (RBIV) under the subgroup II of the genus megalocytivirus (Iridoviridae), which is known to be the major megalocytivirus strain in Korea. The typical histopathological signs were not found in the spleen of rock fish asymptomatically infected by megalocytivirus. Experimental infection of rock bream with the spleen homogenate of the rock fish infected asymptomatically did not induce any mortality unlike the homogenate of infected rock bream with hih mortlity. However, these results may suggest that the asymptomatic infection of megalocytivirus in other fish species can be a potential risk threatening aquaculture industries as a transmission factor of megalocytivirus to susceptible fish species, especially rock bream.

• 한국동물위생학회지
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• 제32권1호
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• pp.1-10
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• 2009

In order to obtain the genetic information of the Korean isolates of porcine circovirus 2 (PCV2), complete genomes of five isolates from Korean PCVD weaned pigs with wasting syndromes were sequenced and compared with those of other published PCV2 isolates. Of the five PCV2 isolates, four (1767 nucleotides) were classified into PCV2b, and one (1,768 nucleotides) was PCV2a. Moreover, it appeared that PCV2b is now the dominant genotype circulating in Korea herds. Total complete genomes of four PCV2b isolates shared $99.1{\sim}99.4%$ nucleotide sequence homology each other, and were only $95.4{\sim}96.2%$ similar to one PCV2a isolate. ORF2 genome of four PCV2b isolates shared over 99% nucleotide sequence and deduced amino acid sequence identity to each other. Nevertheless, those were much divergent with the PCV2a isolate of this study and ranged from $92.3{\sim}92.7%$ nucleotide homology and $91.9{\sim}92.3%$ deduced amino acid sequence homology, respectively. The amino acid sequence alignments of the putative capsid protein identified three major regions of amino acid heterogeneity at residues $59{\sim}91$, $121{\sim}136$ and $190{\sim}210$. Two of those correspond with dominant immunoreactive areas. Phylogenetic analysis based on the complete genome of PCV2 isolates showed that four PCV2b isolates of this study existed the closest relationship with European strains (Netherland, UK and France). One PCV2a isolate was closely related to Japan and North America strains.

• The Plant Pathology Journal
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• 제21권4호
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• pp.334-342
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• 2005

The prototype Chlorella virus PBCV-l encodes 11 tRNA genes and over 350 protein-encoding genes in its 330 kbp genome. Initial attempts to overexpress the recombinant A189/192R protein, a putative virus attachment protein, in E. coli strain BL21(DE3) SI were unsuccessful, and multiple protein bands were detected on Western blots. However, the full-length A189/192R recombinant protein or fragments derived from it were detected when they were expressed in E. coli BL21 CodonPlus (DE3) RIL, which contains extra tRNAs. Codon usage analysis of the a189/192r gene showed highly biased usage of the AGA and AVA codons compared to genes encoded by E. coli and Chlorella. In addition, there were biases of XXA/U($56\%$) and XXG/ C($44\%$) in the codons recognized by the viral tRNAs, which correspond to the codon usage bias in the PBCV-1 genome of XXA/U ($63\%$) over those ending in XXC/G ($37\%$). Analysis of the codon usage in the major capsid protein and DNA polymerase showed preferential usage of codons that can be recognized by the viral tRNAs. The Asn (AAC) and Lys (AAG) codons whose corresponding tRNA genes are duplicated in the tRNA gene cluster were the most abundant (i.e., preferred) codons in these two proteins. The tRNA genes encoded in the PBCV-l genome seem to play a very important role during the synthesis of viral proteins through supplementing the tRNAs that are frequently used in viral proteins, but are rare in the host cells. In addition, these tRNAs would help the virus to adapt to a wide range of hosts by providing tRNAs that are rare in the host cells.

• Journal of Veterinary Science
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• 제22권5호
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• pp.73.1-73.11
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• 2021

Background: Feline calicivirus (FCV) is a common pathogen of felids, and FCV vaccination is regularly practiced. The genetic variability and antigenic diversity of FCV hinder the effective control and prevention of infection by vaccination. Improved knowledge of the epidemiological characteristics of FCV should assist in the development of more effective vaccines. Objectives: This study aims to determine the prevalence of FCV in a population of cats with FCV-suspected clinical signs in Hangzhou and to demonstrate the antigenic and genetic relationships between vaccine status and representative isolated FCV strains. Methods: Cats (n = 516) from Hangzhou were investigated between 2018 and 2020. The association between risk factors and FCV infection was assessed. Phylogenetic analyses based on a capsid coding sequence were performed to identify the genetic relationships between strains. In vitro virus neutralization tests were used to assess antibody levels against isolated FCV strains in client-owned cats. Results: The FCV-positive rate of the examined cats was 43.0%. Risk factors significantly associated with FCV infection were vaccination status and oral symptoms. Phylogenetic analysis revealed a radial phylogeny with no evidence of temporal or countrywide clusters. There was a significant difference in the distribution of serum antibody titers between vaccinated and unvaccinated cats. Conclusions: This study revealed a high prevalence and genetic diversity of FCV in Hangzhou. The results indicate that the efficacy of FCV vaccination is unsatisfactory. More comprehensive and refined vaccination protocols are an urgent and unmet need.