• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.962-966
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• 2020

Monitoring the mutation dynamics of human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical in understanding its infectivity, virulence and pathogenicity for development of a vaccine. In an "age of mobility," the pandemic highlights the importance and vulnerability of regionalization and labor market interdependence in Southeast Asia. We intend to characterize the genetic variability of viral populations within the region to provide preliminary information for regional surveillance in the future. By analyzing 142 complete genomes from South East Asian (SEA) countries, we identified three central variants distinguished by nucleotide and amino acid changes.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.473-480
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• 2017

Plasmodium vivax merozoite surface protein-1 (PvMSP1) gene codes for a major malaria vaccine candidate antigen. However, its polymorphic nature represents an obstacle to the design of a protective vaccine. In this study, we analyzed the genetic polymorphism and natural selection of the C-terminal 42 kDa fragment within PvMSP1 gene ($PvMSP1_{42}$) from 77 P. vivax isolates, collected from imported cases of China-Myanmar border (CMB) areas in Yunnan province and the inland cases from Anhui, Yunnan, and Zhejiang province in China during 2009-2012. Totally, 41 haplotypes were identified and 30 of them were new haplotypes. The differences between the rates of non-synonymous and synonymous mutations suggest that $PvMSP1_{42}$ has evolved under natural selection, and a high selective pressure preferentially acted on regions identified of $PvMSP1_{33}$. Our results also demonstrated that $PvMSP1_{42}$ of P. vivax isolates collected on China-Myanmar border areas display higher genetic polymorphisms than those collected from inland of China. Such results have significant implications for understanding the dynamic of the P. vivax population and may be useful information towards China malaria elimination campaign strategies.

• 대한의생명과학회지
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• 제12권3호
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• pp.209-215
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• 2006

The mutability and frequency of genetic reassortment characteristic of rotavirus and resultant antigenic changes make the rotavirus formidable challenges for control efforts such as the vaccine development. An alternative approach to overcome these difficulties in development of the rotavirus vaccine is to develop effective inhibitors of the virus infection. As an effort to achieve this, effects of glycyrrhetinic acid (GA), which is an active component of glycyrrhizin, on MA-14 cell infection were examined by employing the human rotavirus isolated from Korea, K-21. The data obtained showed that MA-104 cell infection of the K-21 rotavirus was greatly influenced by the presence of both $18{\alpha}-Ga\;and\;18{\beta}-GA$. Both types of GA have inhibited more than 60% of the rotaviral infection at the concentration of 7.68mM. This inhibition effect became much more evident at the higher concentrations of GA. However, the type of GA did not make much differences on the inhibition effect of the drug. Although GA has to be used in high concentrations to exhibit anti-viral activity and to be virostatic, a long history of safe and high dose usage of licoriece in clinical settings in the Far East makes the GA as an attractive inhibitor of the rotaviral infection.

• 대한바이러스학회지
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• 제28권2호
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• pp.139-146
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• 1998

Recombinant polioviruses have been developed by many research groups for use as vaccine vector because poliovirus induces mucosal immunity as well as humoral immunity through oral uptake. We assessed the potential use of poliovirus as a T-cell epitope carrier. Recombinant poliovirus V129 5L was constructed to have a substituted T-helper epitope from the core protein of Hepatitis B virus at neutralization antigenic site 1 on its VP1 capsid protein. The recombinant virus replicated less efficiently than type 1 poliovirus Mahoney strain. The V129 5L formed a little smaller plaques than the Mahoney strain and showed some 1.25 log unit lower titer at the peak in the one-step growth kinetics though it had similar growth profile to that of the Mahoney strain. Since V129 5L recombinant virus was genetically stable even after 24 successive passages in HeLa cells, the antigenic site 1 on VP1 capsid protein was confirmed for its ability of carrying T cell epitope. The genetic stability of V129 5L also indicated that recombinant poliovirus can be successfully utilized for the development of the multivalent vaccines.

• Genomics & Informatics
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• 제15권2호
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• pp.69-80
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• 2017

In this study, cytolethal distending toxin (CDT) producer isolates genome were compared with genome of pathogenic and commensal Escherichia coli strains. Conserved genomic signatures among different types of CDT producer E. coli strains were assessed. It was shown that they could be used as biomarkers for research purposes and clinical diagnosis by polymerase chain reaction, or in vaccine development. cdt genes and several other genetic biomarkers were identified as signature sequences in CDT producer strains. The identified signatures include several individual phage proteins (holins, nucleases, and terminases, and transferases) and multiple members of different protein families (the lambda family, phage-integrase family, phage-tail tape protein family, putative membrane proteins, regulatory proteins, restriction-modification system proteins, tail fiber-assembly proteins, base plate-assembly proteins, and other prophage tail-related proteins). In this study, a sporadic phylogenic pattern was demonstrated in the CDT-producing strains. In conclusion, conserved signature proteins in a wide range of pathogenic bacterial strains can potentially be used in modern vaccine-design strategies.

• Journal of Preventive Medicine and Public Health
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• 제40권2호
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• pp.185-190
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• 2007

Objectives : Since the first human infection from avian influenza was reported in Hong Kong in 1997, many Asian countries have confirmed outbreaks of highly pathogenic H5N1 avian influenza viruses. In addition to Asian countries, the EU authorities also held an urgent meeting in February 2006 at which it was agreed that Europe could also become the next target for H5N1 avian influenza in the near future. In this paper, we provide the general and applicable information on the avian influenza in the bioinformatics field to assist future studies in preventive medicine. Methods : We introduced some up-to-date analytical tools in bioinformatics research, and discussed the current trends of avian influenza outbreaks. Among the bioinformatics methods, we focused our interests on two topics: pattern analysis using the secondary database of avian influenza, and structural analysis using the molecular dynamics simulations in vaccine design. Results : Use of the public genome databases available in the bioinformatics field enabled intensive analysis of the genetic patterns. Moreover, molecular dynamic simulations have also undergone remarkable development on the basis of the high performance supercomputing infrastructure these days. Conclusions : The bioinformatics techniques we introduced in this study may be useful in preventive medicine, especially in vaccine and drug discovery.

• 한국동물위생학회지
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• 제28권4호
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• pp.375-385
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• 2005

The present study was conducted to investigate the genetic profile of two prevalent avian pathogens in Korea namely, Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV). Two farms located in Yeongi-gun, Chungnam were selected for this study. The two viruses were isolated from various organs (spleen, trachea, bursa of Fabricius) of deceased chickens that showed clinical symptoms of Newcastle Disease or Infectious bursal disease like swelling and congestion of the F bursa, facial edema, lacrimation, greenish yellow diarrhea as well as pathological signs like airsacculitis, haemorrhages in the intestines and so on. For analysis of NDV and IBDV, a 466 and 435 base pair fragments corresponding to the HN and VP2 regions which are highly conserved among related strains of NDV and IBDV, respectively, were amplified by RT-PCR and analyzed by sequencing. Comparison of the VP2 region showed a $99.3\%$ homology between the Korean IBDV isolate and the BJ836-attenuated vaccine strain. In contrast, the HN region of the Korean NDV isolate only has an 83 to $84\%$ homology with the vaccine strains LaSota, B1 and VGGA. Our findings reveal that the prevalent NDV strain in Korea is genetically different from the vaccine strains and may explain the recent outbreaks of Newcastle disease in the region.

• Parasites, Hosts and Diseases
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• 제45권1호
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• pp.59-63
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• 2007

Merozoite surface protein-1(MSP-1) and merozoite surface protein-2(MSP-2) were used to develop vaccines and to investigate the genetic diversity in Plasmodium falciparum malaria in Iran. Nested polymerase chain reaction amplification was used to determine polymorph isms of block 2 of the MSP-1 and the central domain of MSP-2 genes. A total of 67 microscopically positive P. falciparum infected individuals from a major endemic region, southeast Iran, were included in this trial. Nine alleles of MSP-1 and 11 alleles of MSP-2 were identified. The results showed that amplified product from these surface antigen genes varied in size and there was specific pattern for each isolate. Besides, regarding this pattern, 23 multiple infections with at least 2 alleles were observed. While the endemic regions of malaria in Iran is classified in low to moderate group, but extensive polymorphism was observed for each marker and the MSP-2 central repeat was the most diverse that could be considered in designing malaria vaccine.

• Parasites, Hosts and Diseases
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• 제39권4호
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• pp.313-318
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• 2001

The identification , characterization and quantification of Plasmodium sp. genetic polymorphism are becoming increasingly important in the vaccine development. We investigated polymorphism of Plasmodium vivax GAM-1 (PvGAM-1) gene in 30 Korean isolates. The polymorphic region of the PvGAM-1 gene, corresponding to nt 3792-4029, was amplified using polymerase chain reaction (PCR) followed by sequencing. All of the P. viuax Korean isolates were one type of GAM-1 gene, which were identical to that of the Belem strain. It is suggested that PvGAM-1 could not be used as a genetic marker for identifying or classifying P. vivax Korean isolates. It revealed that the polymorphic pattern as acquired basically by duplication and modification or deletion event of a 33 bp-motif fragment ended by poly guanine (G) and that there were at least three complete and one partial 33 Up-motif sequences within the polymorphic region in the longest cases such as those of South Korean and Belem isolates. In addition, we clustered P. vivax isolates with parsimonious criteria on the basis of PvGAM- 1 polymorphic patterns (insertion/deletion patterns) .

• 수산해양교육연구
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• 제27권5호
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• pp.1508-1521
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• 2015

Vibrio harveyi is a pathogenic marine bacterium causing systemic symptoms resulting in mass mortalities in fishes and shrimps in aquaculture. Outer membrane proteins(OMPs) are related to the pathogenicity and thus good targets for diagnosis and vaccination for Gram negative bacteria. Recently vaccination strategies using the OMPs have been suggested to control vibriosis in several fish species. In this study, we have isolated V. harveyi from diseased marine fishes from different regions of Korea and investigated genetic variations of four OMP genes including OmpK, OmpU, OmpV and OmpW. Consequently, OmpK and U genes could be divided into 3 subgroups of type I, II, III and type A, B, C, respectively, without any correlation with geographical regions and species while OmpV and W were highly homologous. OmpW gene of V. harveyi FP4138 was fully sequenced and predicted the deduced amino acid sequence to form ${\beta}-barrel$ with hydrophobic channel. Indeed, the immunogenicity of recombinant OmpW produced in Escherichia coli was assessed by vaccinating flounder. As a result, the high antibody response with antibody titer of $4.2{\pm}0.7$ and protection with relative percent survival of 60% against artificial infection of V. harveyi were demonstrated. This result indicates that OmpW is a virulence related factor and it can be a vaccine candidate to prevent a high mortality caused by V. harveyi infection in olive flounder, Paralichthys olivaceus.