• 한국가금학회지
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• 제37권3호
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• pp.283-287
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• 2010

본 연구에서는 SE에 특이적인 박테리오파아지($CJ{\phi}07$)의 사료 및 음수 투여가 어린 병아리의 SE 감염에 따른 장내 균증식과 체외 균배출에 미치는 영향을 평가하고자 실시하였다. 박테리오파아지를 투여한 SPF 병아리에 SE균을 공격 접종 한 뒤, 공격 접종 10일 후 채취한 맹장 분변에 존재하는 SE균 수를 측정한 결과, 박테리오파아지를 투여한 병아리의 맹장 분변 내 SE균 수는 양성 대조군에 비하여 유의성 있게 감소하였다(P<0.05). 또한, 공격 접종 10일 후 사육 시설 표면의 SE균 오염도를 측정한 결과, 박테리오파아지를 투여한 그룹의 사육 시설에서 채취한 환경 시료의 SE균 오염율(50%)이 박테리오파아지를 투여하지 않은 그룹의 SE균 환경 오염율(100%)에 비하여 감소되는 것을 통해 박테리오파아지 $CJ{\phi}07$에 의한 장내 균 증식과 체외 균 배출 억제 효능이 확인되었다. 따라서 박테리오파아지 $CJ{\phi}07$는 항생제 대체 물질로서 가금에서의 SE 감염을 효과적으로 방어할 수 있을 것으로 판단된다.

• 대한수의학회지
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• 제47권3호
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• pp.291-298
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• 2007

Olive flounder, Paralichthys olivaceus is one of the most important cultured fish in Korea, its farming has been negatively impacted by viral, bacterial and parasitic diseases. Streptococcal infection was considered as a serious problem because of significant economic losses in olive flounder farm industry. The development and evaluation of vaccine for protection against infection by this agent were required. We evaluated the safety and efficacy of ${\beta}$-hemolytic Streptococcus (S.) iniae vaccine on olive flounder Three hundreds of flounders (weight $119.8{\pm}20.7g$, body length $22.6{\pm}1.4cm$) were reared in 0.5 tons aquaria in land-marine tank system. Seawater was provided from the sea of Inchon in Korea, and water temperature was set to $22^{\circ}C$ and $25^{\circ}C$ in the vaccination and challenge test, respectively. We used the formalin-inactivated ${\beta}$-hemolytic S. iniae (F2K) vaccine (M VAC INIAE; Kyoritsu seiyaku, Japan) originated in Japan. The vaccine was intraperitoneally administered to fish. Both of vaccinated group and control group were challenged with intraperitoneally injection by virulent S. iniae SI-36 isolates with $1.0{\times}10^7CFU/fish$ at 3 weeks after vaccination. Difference on mortality of control and vaccinated group (90.0 and 15.0%, 76.5 and 8.0% respectively) at two trials were found significant (p<0.05), and relative percent survival were 83.4% and 89.5%, respectively. The dead fishes were showed dark pigmentation of skin, abdominal extension, hemorrhagic ascites, and liver necrosis, and isolated the S. iniae strain from ascites, liver and kidney. We confirmed the safety and efficacy of ${\beta}$-hemolytic S. iniae vaccine by determinations of the optimal management condition and artificial challenge test in olive flounder.

• Parasites, Hosts and Diseases
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• 제56권4호
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• pp.325-334
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• 2018

Toxoplasma gondii is an apicomplexan zoonotic protozoan parasite that infects most species of warm-blooded animals, including humans. The heavy incidence and severe or lethal damage caused by T. gondii infection clearly indicate a need for the development of an effective vaccine. T. gondii GRA8 is a member of the dense granules protein family and is used as a marker of acute infection. In the present study, we evaluated the protective immunity induced by DNA vaccination based on a recombinant eukaryotic plasmid, pDsRed2-GRA8, against acute toxoplasmosis in mice. BALB/c mice were intramuscularly immunized with the pDsRed2-GRA8 plasmid and then challenged by infection with the highly virulent GFP-RH strain of T. gondii. The specific immune responses and protective efficacy against T. gondii of this vaccine were analyzed by measuring cytokine and serum antibody titers, splenocyte proliferation assays, and the survival times of mice after challenge. Our results showed that mice immunized with pDsRed2-GRA8 demonstrated specific humoral and cellular responses, induced higher IgG antibody titers with predominant IgG2a production; increased levels of IL-10, IL-12 (p70), $IFN-{\gamma}$, $TNF-{\alpha}$, and splenocyte proliferation; and prolonged survival times compared to those of control mice. The present study showed that DNA immunization with pDsRed2-GRA8 induced humoral and cellular immune responses, and all immunized mice showed greater Th1-type immune responses and longer survival times than those of control mice. These results indicated that T. gondii GRA8 DNA immunization induces a partial protective effect against acute toxoplasmosis.

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.31-38
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• 2016

Specific gene expressions of host cells by spontaneous STAT6 phosphorylation are major strategy for the survival of intracellular Toxoplasma gondii against parasiticidal events through STAT1 phosphorylation by infection provoked $IFN-{\gamma}$. We determined the effects of small molecules of tyrosine kinase inhibitors (TKIs) on the growth of T. gondii and on the relationship with STAT1 and STAT6 phosphorylation in ARPE-19 cells. We counted the number of T. gondii RH tachyzoites per parasitophorous vacuolar membrane (PVM) after treatment with TKIs at 12-hr intervals for 72 hr. The change of STAT6 phosphorylation was assessed via western blot and immunofluorescence assay. Among the tested TKIs, Afatinib (pan ErbB/EGFR inhibitor, $5{\mu}M$) inhibited 98.0% of the growth of T. gondii, which was comparable to pyrimethamine ($5{\mu}M$) at 96.9% and followed by Erlotinib (ErbB1/EGFR inhibitor, $20{\mu}M$) at 33.8% and Sunitinib (PDGFR or c-Kit inhibitor, $10{\mu}M$) at 21.3%. In the early stage of the infection (2, 4, and 8 hr after T. gondii challenge), Afatinib inhibited the phosphorylation of STAT6 in western blot and immunofluorescence assay. Both JAK1 and JAK3, the upper hierarchical kinases of cytokine signaling, were strongly phosphorylated at 2 hr and then disappeared entirely after 4 hr. Some TKIs, especially the EGFR inhibitors, might play an important role in the inhibition of intracellular replication of T. gondii through the inhibition of the direct phosphorylation of STAT6 by T. gondii.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.362-366
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• 2005

Actinobacillus pleuropneumoniae is an important pig pathogen, which is responsible for swine pleuropneumonia, a highly contagious respiratory infection. To develop subunit vaccines for A. pleuropneumoniae infection, the Apx toxin genes, apxI and apxII, which are thought to be important for protective immunity, were expressed in Saccharomyces cerevisiae, and the induction of immune responses in mice was examined. The apxI and apxII genes were placed under the control of a yeast hybrid ADH2-GPD promoter (AG), consisting of alcohol dehydrogenase II (ADH2) and the GPD promoter. Western blot analysis confirmed that both toxins were successfully expressed in the yeast. The ApxIA and ApxIIA-specific IgG antibody response assays showed dose dependent increases in the antigen-specific IgG antibody titers. The challenge test revealed that ninety percent of the mice immunized with ApxIIA or a mixture of ApxIA and ApxIIA, and sixty percent of mice immunized with ApxIA survived, while none of those in the control groups survived longer than 36 h. These results suggest that vaccination of the yeast ex­pressing the ApxI and ApxII antigens is effective for the induction of protective immune responses against A. pleuropneumoniae infections in mice.

• 한국환경농학회지
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• 제13권3호
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• pp.288-300
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• 1994

재배지에서 경작된 아스파라거스의 이병조직으로 부터 Fusarium oxysporum이 가장 많이 분리되었고 F. moniliforme와 F. solani가 그다음 순으로 분리되었다. 유묘와 조직배양을 통해 얻은 개체를 이용한 병원성 검정 결과, F. oxysporum과 F. moniliforme는 병원성이 강한 것으로 밝혀졌고, F. solani와 잠두의 배축으로 부터 분리한 비 병원성 F. oxysporum (AVFO)은 병원성이 약하거나 없는 것으로 밝혀졌다. 또한, F. moniliforme가 F. oxysporum 보다 병원성이 더 강한 것으로 밝혀졌고, F. moniliforme가 F. oxysporum보다 더욱 일관된 병원성을 지니고 있음이 밝혀졌다. 비병원성 Fusarium균을 이용한 생물적 방제 실험 결과, 병원성 균주를 접종하기 5-7일전에 비병원성 균주들을 접종하여 방제효과를 거둘 수 있었다. 비병원성 F. oxysporum (AVFO)은 F. oxysporum에 대해서 보다 F. moniliforme에 대해 더욱 효과적인 방제효과를 나타냈고, F. solani는 F. moniliforme에 대해서 보다 F. oxysporum의 방제에 더욱 효과적이었다.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.170-175
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• 2011

This study was carried out for the molecular level identification of recombinant protein vaccine efficacy, by oral feeding against white spot syndrome virus infection, with the comparison of viral mRNA transcriptional levels in shrimp cells. For the determination of WSSV dilution ratio for the vaccination experiment by oral feeding, in vivo virus titration was carried out using different virus dilutions of virus stock ($1{\times}10^2$, $2{\times}10^2$, and $1{\times}10^3$). Among the dilution ratios, $2{\times}10^2$ diluted WSSV stock was chosen as the optimal condition because this dilution showed 90% mortality at 10 days after virus injection. Recombinant viral proteins, rVP19 and rVP28, produced as protein vaccines were delivered in shrimps by oral feeding. The cumulative mortalities of the shrimps vaccinated with rVP19 and rVP28 at 21 days after the challenge with WSSV were 66.7% and 41.7%, respectively. This indicates that rVP28 showed a better protective effect against WSSV in shrimp than rVP19. Through the comparison of mRNA transcriptional levels of viral genes from collected shrimp organ samples, it was confirmed that viral gene transcriptions of vaccinated shrimps were delayed for 4~10 days compared with those of unvaccinated shrimps. Protection from WSSV infection in shrimp by the vaccination with recombinant viral proteins could be accomplished by the prevention of entry of WSSV due to the shrimp immune system activated by recombinant protein vaccines.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.206-216
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• 2015

To clarify the role of surface protective antigen A (SpaA) in the pathogenesis of Erysipelothrix rhusiopathiae C43065 (serotype 2), the spaA deletion mutant of E. rhusiopathiae ${\Delta}spaA$ was constructed by homologous recombination. The virulence of the ${\Delta}spaA$ mutant decreased more than 76-fold compared with that of the wild-type strain C43065 in mice. The mutant strain was sensitive to the bactericidal action of swine serum, whereas the wild-type strain was resistant. The adhesion of wild-type strain to MEF cells was inhibited significantly by treatment with rabbit antiserum against recombinant SpaA (rSpaA) as compared with the treatment with normal rabbit serum, but the mutant strain was not affected. The mutant strain was readily taken up by mouse peritoneal macrophages in the normal rabbit serum, whereas the wild-type strain was resistant. Whereas the rabbit antiserum against rSpaA promoted the phagocytosis of wild-type strain by macrophages, the mutant strain was not affected. In addition, mice vaccinated with the formalin-killed mutant strain were provided 40% protection against challenge by the homologous virulent strain as compared with those with wild-type strain, NaOH-extracted antigen, or rSpaA, which provided more than 80% protection against the same infection. These suggested that SpaA has an important role in the pathogenesis of E. rhusiopathiae infection and could be a target for vaccination against swine erysipelas.

• IMMUNE NETWORK
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• 제7권4호
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• pp.186-196
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• 2007

Background: Although IL-12 has been widely accepted to playa central role in the control of pathogen infection, the use of recombinant IL-12 (rIL-12) as a vaccine adjuvant has been known to be ineffective because of its rapid clearance in the body. Methods: To investigate the effect of sustained release of IL-12 in vivo in the peptide and protein vaccination models, rIL-12 was encapsulated into poly ($A_{DL}$-lactic-co-glycolic acid) (PLGA). Results: We found that codelivery of IL-12-encapsulated microspheres (IL-12EM) could dramatically increase not only antibody responses, but also antigen-specific $CD4^+\;and\;CD8^+$ T cell responses. Enhanced immune responses were shown to be correlated with protective immunity against influenza and respiratory syncytial virus (RSV) virus challenge. Interestingly, the enhancement of $CD8^+$ T cell response was not detectable when $CD4^+$ T cell knockout mice were subjected to vaccination, indicating that the enhancement of the $CD8^+$ T cell response by IL-12EM is dependent on $CD4^+$ T cell "help". Conclusion: Thus, IL-12EM could be applied as an adjuvant of protein and peptide vaccines to enhance protective immunity against virus infection.

• 한국해양바이오학회지
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• 제1권3호
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• pp.163-169
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• 2006

본 연구에서는 비장 내의 비대해진 세포 존재와 조직 괴사라는 병리조직학적 관찰에 의하여 우리 나라의 pearl gourami (Trichogaster leeri)에서 iridovirus에 의한 자연 감염이 나타남을 확인하였다. 이러한 iridovirus 감염을 더욱 정확하게 진단하기 위해서 iridovirus 감염 진단에 주로 사용되는 MCP와 ATPase gene 부위에서 2 primer sets를 제작하여 PCR을 실시한 결과, PCR 생성물은 기대한 size와 부합하게 나타났고, MCP gene 부위의 염기서열은 reference strain인 ISKNV와 매우 높은 유사성 (99.6%)을 보였다. 공격 실험을 통하여 pearl gourami에서 분리된 iridovirus의 병원성을 확인하였고, 무분별한 관상어 관리에 의하여 관상어로부터 양식어류에로의 질병 전이가 나타남으로서 일어날 수 있는 국내 양식 산업에 대한 위험성을 제시하였다.