• Journal of fish pathology
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• v.37 no.1
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• pp.71-78
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• 2024

Streptococcosis, caused by Streptococcus iniae and Streptococcus parauberis is an important bacterial disease that affects in olive flounder in Korea. In Korea, multivalent bacterial vaccines are used to prevent streptococcal diseases in aquaculture. In this study, commercial vaccines containing formalin-inactivated bacterial cells of S. iniae and S. parauberis were administered at six fish farms and one unvaccinated fish farm were designated for investigation (Wando; 4 sites and Jeju; 3 sites). Blood was collected from vaccinated and unvaccinated olive flounders, and titers of antibodies against S. iniae and S. parauberis in serum were analyzed using ELISA. After a one shot vaccination in the farms at Jeju (farm A) and Wando (farm D), the proportion of individuals with specific antibodies against S. parauberis OD values of 0.4 or higher was 60% and 53.5%, respectively. But after booster vaccination, the proportion of individuals with serum OD values of 0.4 or higher was higher substantially increased to 96.6% (farm A) and 100% (farm D). The levels of S. parauberis specific antibodies of olive flounder were increased after vaccination in three fish farms (farm D, E, and F), but not S. iniae specific antibodies.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.663-672
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• 2024

The use of nanoparticles as a delivery system for a specific antigen could solve many limitations of mucosal vaccine applications, such as low immunogenicity, or antigen protection and stabilization. In this study, we tested the ability of nasally administered chitosan nanoparticles loaded with glycoprotein B of murine cytomegalovirus to induce an immune response in an animal model. The choice of chitosan nanoparticle type was made by in vitro evaluation of sorption efficiency and antigen release. Three types of chitosan nanoparticles were prepared: crosslinked with tripolyphosphate, coated with hyaluronic acid, and in complex with polycaprolactone. The hydrodynamic size of the nanoparticles by dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, scanning electron microscopy, stability, loading efficiency, and release kinetics with ovalbumin were evaluated. Balb/c mice were immunized intranasally using the three-dose protocol with nanoparticles, gB, and adjuvants Poly(I:C) and CpG ODN. Subsequently, the humoral and cell-mediated antigen-specific immune response was determined. On the basis of the properties of the tested nanoparticles, the cross-linked nanoparticles were considered optimal for further investigation. The results show that nanoparticles with Poly(I:C) and with gB alone raised IgG antibody levels above the negative control. In the case of mucosal IgA, only gB alone weakly induced the production of IgA antibodies compared to saline-immunized mice. The number of activated cells increased slightly in mice immunized with nanoparticles and gB compared to those immunized with gB alone or to negative control. The results demonstrated that chitosan nanoparticles could have potential in the development of mucosal vaccines.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.103-114
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• 1989

Reciprocal crosses were conducted between three strains of Taiwan Country chickens, developed in the National Chung-Hsing University, and two strains of Single Comb White Leghorns, developed in the Taiwan Livestock Research Institute. Traits studied were growing performances, laying performances, egg quality traits and traits concerning disease resistance, including resistance to Marek's disease virus and immune responses to Newcastle disease virus vaccine and to sheep red blood cell. Results indicated that laying performances of Taiwan country chickens were much inferior to White Leghorns, but they matured earlier, their eggs had better shell strength and larger proportion of yolk, and their general disease resistance was much better than White Leghorns. Heterosis were found in laying performances and egg quality traits. The heterosis in laying traits was so large that the hybrid laid as many eggs and as large eggs as did pure strains of White Leghorns. Strategies on the improvement of native chickens and the utilization of genetic merits of native chickens were also discussed.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.142-147
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• 2005

The objective of this study was to develop a new potent antibacterial compound against bovine pneumoniae bacteria from medicinal plants or herbs. Among 65 kinds of medicinal plants and herbs, ethanol extracts of Citrus unishiu showed the highest solid yield of $54\%$. However, ethanal extracts from Agastache rugosa had the highest antibacterial activities against bovine pneumoniae bacteria, Mannheimia haemolytica A and Haemophilus somnus (size of clear zone: 16.0 mm and 10.0 mm, respectively). The antibacterial compound was also maximally extracted when the powder of A. rugosa was treated with $70\%$ ethanol at $45^{\circ}C$ for 12 hours.

• Korean Journal of Veterinary Research
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• v.59 no.3
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• pp.157-160
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• 2019

The production of rmtB-encoded 16S rRNA methylases has emerged as a novel mechanism promoting high-level resistance toward aminoglycosides in Gram-negative bacteria. Between 2015 and 2017, 636 distinct commensal Escherichia (E.) coli isolates were collected from different farms in South Korea to determine the prevalence and molecular characteristics of rmtB. The positive rates of rmtB between all the isolates and amikacin-resistant isolates were 1.1 and 100%, respectively. High-level aminoglycoside resistance could be transferred by conjugation from rmtB-positive donors to higher amikacin-resistance efficacies. This is the first report of 16S rRNA methylase-encoding genes in E. coli isolated from food-producing animals in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.45-45
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, RAL increased the production of immunostimulatory mediators and phagocytotic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activation of JNK and PI3K/AKT signaling was reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.125-131
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• 2004

Tuberculosis (TB) remains an enormous global health problem, and a new vaccine against TB more potent than the current inadequate BCG vaccine is urgently needed. We constructed three recombinant Mycobacterium bovis BCG (rBCG) strains over-expressing antigen (Ag) 85A, Ag85B, or both of M. tuberculosis using their own promoter and secretory sequence, or hsp60 promoter. SDS-PAGE analysis of rBCG proteins showed overexpression of Ag85A and Ag85B proteins in higher level than of those in their parental strain of BCG. In addition, rBCG(rBCG/B.FA) over-expressing Ag85A and Ag85B induced strong IFN-${\gamma}$ production in splenocytes. However, there was no significant difference in protective efficacy between rBCG and their parental BCG strain. In this study, therefore, rBCG over-expressing Ag85A, Ag85B, or both failed to show enhanced protection against M. tuberculosis infection in a mouse model.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.61-68
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• 2003

Streptococcus mutans is known to be a major causative organism of human dental caries. The development of a vaccine against dental caries involves identification of appropriate antigens of mutans streptococci against which protective immune responses can be mounted, and the selection of a method of immunization that will generate sustained levels of protective antibodies. Antigens receiving most attention include streptococcal surface proteins that are involved in attachment to tooth surfaces and glucosyltransferases (GTF) that synthesize adhesive glucans from sucrose. The induction of antibody responses to orally administered antigens is often difficult due to digestive destruction of antigens and immune tolerance. Here we report the induction of antibody responses to an anti-caries vaccine containing retinoic acid (RA). Subcutaneous immunization with formalin-fixed bacteria or GTF supplemented with RA induced higher serum IgM and IgA responses to GTF compaired to oral adminstration. Antisera induced by Ingbritt strain showed partial cross-reaction with LM-7 strain, but not with OMZ175. These results suggest that subcutaneous immunization with GTF combined with an immunomodulator, RA, may be applied to anti-caries vaccine.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.408-419
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• 2016

Background: In recent years, adjuvants have received increasing attention owing to the development of purified subunit and synthetic vaccines which are poor immunogens and require additional adjuvants to evoke an immune response. Therefore, immunologic adjuvants have been developed and tested. Plant polysaccharides have been recognized as effective biological response modifiers with low toxicity. Methods and Results: In this study, the polysaccharide from the aboveground part of Astragalus membranaceus Bunge containing immunomodulating arabino-3,6-galactan was evaluated for its hemolytic activity and adjuvant potential in the specific cellular and humoral immune responses to ovalbumin. The polysaccharide from the aboveground part of Astragalus membranaceus Bunge was co-immunized with the purified Vi capsular polysaccharide of Salmonella typhi vaccine in mice. The polysaccharide from the aboveground part of Astragalus membranaceus Bunge did not induce any hemolytic activity or side effects at doses up to $500{\mu}g/m{\ell}$. The concanavalin A-, lipopolysaccharide-, and ovalbumin-induced splenocyte proliferation and serum ovalbumin-specific IgG, IgG1 and IgG2b antibody titers in immunized mice were significantly enhanced by AMA. Pharmacological data revealed that the polysaccharide from the aboveground part of Astragalus membranaceus Bunge increased antigen-specific antibody levels in immunized mice. The polysaccharide from the aboveground part of Astragalus membranaceus Bunge-adjuvanted purified Vi capsular polysaccharide of Salmonella typhi vaccine improved the proliferation of splenocytes and macrophages as well as stimulated cytokine production. Conclusions: These results suggest that the polysaccharide from the aboveground part of Astragalus membranaceus Bunge-adjuvanted vaccines enhanced humoral and cellular immunity and that the polysaccharide from the aboveground part of Astragalus membranaceus Bunge is a safe and efficacious adjuvant candidate suitable for use in prophylactic and therapeutic vaccines.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1701-1710
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• 2017

Classical swine fever virus (CSFV) is the etiologic agent of classical swine fever, a highly contagious disease that causes significant economic losses to the swine industry. The lapinized C-strain, a widely used vaccine strain against CSFV, has low growth efficiency in cell culture, which limits the productivity in the vaccine industry. In this study, a recombinant virus derived from C-strain was constructed and subjected to continuous passaging in PK-15 cells with the goal of acquiring a high progeny virus yield. A cell-adapted virus variant, RecCpp80, had nearly 1,000-fold higher titer than its parent C-strain but lost the ability to induce fever in rabbits. Sequence analysis of cell-adapted RecC variants indicated that at least six nucleotide changes were fixed in RecCpp80. Further adaption of RecCpp80 variant in swine testicle cells led to a higher virus yield without additional mutations. Introduction of each of these residues into the wild-type RecC backbone showed that one mutation, M979R (T3310G), located in the C-terminal region of E2 might be closely related to the cell-adapted phenotype. Rabbit inoculation revealed that $RecCpp40_{+10}$ failed to induce fever in rabbits, whereas $RecCpp80_{+10}$ caused a fever response similar to the commercial C-strain vaccine. In conclusion, the C-strain can be adapted to cell culture by introducing specific mutations in its E2 protein. The mutations in RecCpp80 that led to the loss of fever response in rabbits require further investigation. Continuous passaging of the C-strain-based recombinant viruses in PK-15 cells could enhance its in vitro adaption. The non-synonymous mutations at 3310 and 3531 might play major roles in the enhanced capacity of general virus reproduction. Such findings may help design a modified C-strain for improved productivity of commercial vaccines at reduced production cost.