• Korean Journal of Veterinary Service
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• v.21 no.2
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• pp.117-126
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• 1998

This study was performed to investigate the immunogenicity of autogenous E coli vaccines and their preventive effects on diarrhea in suckling piglets. Autogenous E coli live and killed vaccines were made from the E coli strains isolated from piglets showing diarrhea in field. In group I, pregnant sows were administered with live and killed vaccines at 4 and 2 weeks before parturition, respectively, Killed vaccines were administered twice to pregnant sows at 4 and 2 weeks before parturition in group II, and saline instead of autogenous E coli vaccines was administered to pregnant sows in group III for the control. After parturition, antibody titers in colostrum and milk from sows, incidence of diarrhea in suckling piglets, and immunoreactivity in the ileum of piglets from each treatment group were examined. The results were as follows ; 1. Sixty-two strains of E coli were isolated from suckling piglets with diarrhea. Of the strains, K88 pilus and K99 pilus antigens were identified in 6(9.8%) and 4(6.5%), respectively. Molecular weights of K88 and K99 pilus were 27,500 and 18,500 daltons, respectively. 2. Antibody titers in colostrum from sows after parturition were 1 : 512 to 1 : 1,024 in group I, 1.256 to 1.512 in group II, and 1 : 4 to 1 : 16 in group III. 3. The incidences of diarrhea In suckling piglets of group I, II and III were 3.3%, 9.4% and 21.4%, respectively. 4. When the immunoreactivity in the ileum of piglets from each group was examined, the proportion of IgG-immunoreactivity cells in group I or II was higher than that in group III. In conclusion, administration of autogenous E coli vaccines to pregnant sows before parturition can be an effective way to prevent diarrhea in suckling piglets.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.330-338
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• 2019

Chronic infection with intracellular Brucella abortus (B. abortus) in livestock remains as a major problem worldwide. Thus, the search for an ideal vaccine is still ongoing. In this study, we evaluated the protective efficacy of a combination of B. abortus recombinant proteins; superoxide dismutase (rSodC), riboflavin synthase subunit beta (rRibH), nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12) and malate dehydrogenase (rMDH), cloned and expressed into a pMal vector system and $DH5{\alpha}$, respectively, and further purified and applied intraperitoneally into BALB/c mice. After first immunization and two boosters, mice were infected intraperitoneally (IP) with $5{\times}10^4CFU$ of virulent B. abortus 544. Spleens were harvested and bacterial loads were evaluated at two weeks post-infection. Results revealed that this combination showed significant reduction in bacterial colonization in the spleen with a log protection unit of 1.31, which is comparable to the average protection conferred by the widely used live attenuated vaccine RB51. Cytokine analysis exhibited enhancement of cell-mediated immune response as IFN-${\gamma}$ is significantly elevated while IL-10, which is considered beneficial to the pathogen's survival, was reduced compared to control group. Furthermore, both titers of IgG1 and IgG2a were significantly elevated at three and four-week time points from first immunization. In summary, our in vivo data revealed that vaccination with a combination of five different proteins conferred a heightened host response to Brucella infection through cell-mediated immunity which is desirable in the control of intracellular pathogens. Thus, this combination might be considered for further improvement as a potential candidate vaccine against Brucella infection.

• Korean Journal of Veterinary Service
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• v.14 no.1
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• pp.49-61
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• 1991

The present study was conducted to investigate biochemical, serologic, and pathogenic characteristic of E. rhusiopathiae isolated from the cases of acute septicemic swine erysipelas in Youngnam provinces during the period from June 1988 to September 1990. The majority of biochemical and cultural properties of E. rhusiopathiae isolated from pigs affected with acute erysipelas were identical to those of the standard strain employed. All of the 45 isolates were serotype la. All isolates were highly susceptible to penicillin G, lincomycin, cephalothin, ampicillin, erythromycin (MIC : 0.025-0.78IU or ${\mu}g$ / ml ), and moderately susceptible to oleandomycin, oxytetracycline, chloramphenicol (MIC : 0.78-25${\mu}g$ / ml ). Kanamycin and sulfadimethoxine showed no activity against the isolates(MIC : ＞400${\mu}g$ / ml ). The MICs of dihydrostreptomycin presented two distribution peaks ; of 45 strains, 5(11.1%) were resistant to dihydrostreptomycin(MIC : 400${\mu}g$ / ml ). All of 5 selected isolates were pathogenic for mite and $LD_{50}$ was $3.7{\times}10^3$viable cells. Mice immunized subcutaneously with live vaccine did not die after challenge to virulent isolates of E. rhusiopathiae.

• Journal of Microbiology
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• v.40 no.1
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• pp.1-10
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• 2002

At the dose of 1000 p.f.u. per mouse,100% mortality occurred in mice inoculated with wild-type pseudorabies virus (PrV). In contrast, upon stable deletion of 10 bp nucleotides at the Bsrl site within the TK gene, PrV was rendered to be completely apathogenic. The deletion also caused the virus to be less capable of replicating in respiratory as well as in nervous system tissues. Although animals were exposed to high titers of TK-deleted PrVs, the virus failed to replicate to a high titer as compared to the pathogenic parental virus. In contrast to previous studies the deletion in the TK gene did not prevent the virus from establishing latency. Upon immunosuppression, the latent virus? however, reactivated but replicated at low titers. Interestingly, TK-deleted virus established latency and reactivation, that are occurred only in trigeminal ganglia and the cerebrums and no other tissues involved. Following reactivation, there was no indication of virus shedding in respiratory tissues as confirmed by virus isolation and polymerase chain reaction (PCR) technique targeting at the gB gene of PrV, The non-pathogenic virus with non-shedding characteristics, upon reactivation of the latent virus, would be the important feature of a live virus vaccine candidate.

• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.239-242
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• 2006

To evaluate the protoscolicidal effects of various concentrations of hypertonic glucose, live protoscolices of sheep were exposed to 10%, 15%, 25% and 50% glucose solutions. Cetrimide (0.5%), silver nitrate (0.5%) and hypertonic saline (20%) were used as positive controls, while physiological saline was used as a negative control. After 1, 2 and 5 min, the protoscolicidal effects were determined by 1 % eosin. A 25% glucose solution had no significant protoscolicidal effect. However, a 50% glucose solution revealed higher protoscolicidal effect than 0.5% silver nitrate but weaker effect than 0.5% cetrimide; the effect was comparable with that of 20% hypertonic saline. The results showed that hypertonic glucose solution is highly effective in killing protoscolices of Echinococcus granulosus in vitro.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1919-1927
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• 2006

Tumor cells genetically engineered to secrete cytokines are effective in tumor therapy, but various unexpected side effects are observed, which may result from the bulk activation of various bystander cells. In this study, we tested tumor vaccines expressing various membrane-bound forms of IL-2 (mbIL-2) on MethA fibrosarcoma cells to focus antitumor immune responses to CTL. Chimeric forms of IL-2 with whole CD4, deletion forms of CD4, and TNF were expressed on the tumor cell surface, respectively. Tumor clones expressing mbIL-2 or secretory form of IL-2 were able to support the cell growth of CTLL-2, an IL-2-dependent T cell line, and the proliferation of spleen cells from 2C TCR transgenic mice that are responsive to the $p2Ca/L^d$ MHC class I complex. Expression of mbIL-2 on tumor cells reduced the tumorigenicity of tumor cells, and the mice that once rejected the live IL-2/TNF tumor clone acquired systemic immunity against wild-type MethA cells. The IL-2/TNF clone was inferior to other clones in tumor formation, and superior in the stimulation of the CD8+ T cell population in vitro. These results suggest that the IL-2/TNF clone is the best tumor vaccine, and may stimulate CD8+ T cells by direct priming. Expression of IL-2/TNF on tumor cells may serve as an effective gene therapy method to ameliorate the side effects encountered in the recombinant cytokine therapy and the conventional cytokine gene therapy using the secretory form of IL-2.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.379-382
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• 2001

To confirm the effect of food and water deprivation prior to Newcastle disease(ND) virus vaccination, three hundred chicks were divided into five groups with three replications. ND vaccine were sprayed to at 1 -day old chicks at commercial hatchery. Secondary and third vaccination was conducted at 2-week old and 24-day old chicks by LaSota strain. Control was conventionally vaccinated without withdrawing the food and water before or after vaccination. In group 2(G2) and 3(G3), LaSota strain was vaccinated to chicks before and after fasting the food and water for 3 and 2 hours, respectively. Group 4(G4) has the same fasting time of group 2, but supplemented the skim milk in vaccin dilution water. In group 5(G5), skim milk was added into group 3. Weight gain, feed intake and feed conversion were weekly measured for 5 weeks. Blood was collected from wing vein at 24 and 35 days of age. Each serum antibody level were measured by hemagglutination inhibition(HI) test. The average weight gain, feed intake, feed conversion of all group were not significantly different. Weight gain of each groups was 1910.30(control), 1875.28(G2), 1952.12(G4) and 1896.05(G5), respectively. Feed intake of all group was recorded at 3160.67(control), 3167.07(G2), 3189.48(G3), 3157.85(G4) and 3178.16(G5), respectively. The feed conversion of each groups was 1.655(control), 1.688(G2), 1.633(G3), 1.699(G4) and 1.676(G5), respectively. The HI titer of G4 was $ 5.50{\Pm}$1.40 and significantly higher than the other groups (p<0.05)(control : $4.36{\Pm}$1.87 , G2 : $5.18{\Pm}$2.14, G3 : $4.51{\Pm}$2.19, G : $5.28{\Pm}$1.58 at 35 days old. The results of this experiment indicated that two or three hours of fasting time before or after vaccination would be able to show the higher antibody level against ND virus.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.712-717
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• 2010

Cytochrome P450 enzymes (P450s) are involved in the synthesis of a wide variety of valuable products and in the degradation of numerous toxic compounds. The P450 BM3 (CYP102A1) from Bacillus megaterium was the first P450 discovered to be fused to its redox partner, a mammalian-like diflavin reductase. Here, we report the development of a whole-cell biocatalyst using ice-nucleation protein (Inp) from Pseudomonas syringae to display a hemeand diflavin-containing oxidoreductase, P450 BM3 (a single, 119-kDa polypeptide with domains of both an oxygenase and a reductase) on the surface of Escherichia coli. The surface localization and functionality of the fusion protein containing P450 BM3 were verified by flow cytometry and measurement of enzymatic activities. The results of this study comprise the first report of microbial cell-surface display of a heme- and diflavin-containing enzyme. This system should allow us to select and develop oxidoreductases containing heme and/or flavins into practically useful whole-cell biocatalysts for extensive biotechnological applications, including selective synthesis of new chemicals and pharmaceuticals, bioconversion, bioremediation, live vaccine development, and biochip development.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.689-696
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• 2003

Canine sarcoptic mite (Sarcoptes scabiei var. canis) burrow usually in the stratum corneum of the skin of dogs and rabbits. Antigens from the burrowing mites induce cutaneous inflammatory reaction and humoral and cell-mediated immune response in the host. The effect of immunization induced by somatic antigens of house dust mite (Dermatophagoides spp.) has been evaluated to control the canine sarcoptic mite in this experiment. Twelve common antigens (187, 142, 126, 120, 109, 92, 80, 68, 51, 30, 25, 17 kDa) were found using SDS-PAGE with silver staining and Western blot between canine sarcoptic mite and house dust mite. In order to evaluate the immunologic effect of these common antigens 10 New Zealand white rabbits were divided as 4 groups such as negative control (group I), positive challenged control (group II), vaccinated (group III), and vaccinated-challenged (group IV) groups. Group II was artificially infested with about 1,000 canine sarcoptic mites and group III and IV were immunized with somatic antigens of house dust mite. In addition group IV was artificially infested with about 1,000 canine sarcoptic mites and group II, IV were treated with ivermectin. At the 8 weeks of the vaccination with common antigen, the antibody titers of all groups of II, III and IV had been increased. Both infestation score and live canine sarcoptic mite counts of group IV were lower than group III. Infestation score of group II become 0 by 2 weeks and group IV by 4 weeks after infestation. These results suggest that house dust mite, which is easy to culture in vitro, can be a vaccine candidate for protection of canine sarcoptic mite infestation.

• Korean Journal of Veterinary Research
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• v.53 no.2
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• pp.95-101
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• 2013

The study was carried out to evaluate and compare the immune responses in mice experimentally infected with either wild-type or isogenic mutants of Salmonella enterica serovars Enteritidis (SE), Salmonella Typhimurium (ST) and Gallinarum (SG). The mutant strains were constructed by allelic replacement of some virulence-associated genes in the wild-type strains. Seven-week-old female BALB/c mice were orally or intraperitoneally inoculated by injecting bacterial suspension. To evaluate the immune responses, enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay were conducted with serum and fecal samples. As a result, the mice group infected orally with the SE mutant strain showed the highest level of specific IgA-secreting splenocytes, compared to the other groups. The peritoneally injected groups showed the greater levels of IgG1 than the orally injected groups, which was in a good agreement with the previous studies. In addition, the mutant infected groups had the similar secretion levels of antibodies with the wild-type infected groups. These results demonstrated that the SE mutant strain elicited humoral immune response as much as wild-type, implying that it can be useful as a delivery vehicle as well as a candidate of a live attenuated vaccine.