• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.241-246
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• 2015

To develop a live vaccine strain against fowl typhoid and paratyphoid caused by Salmonella serovar Gallinarum biovar Gallinarum (Salmonella Gallinarum) and Salmonella serovar Enteritidis (Salmonella Enteritidis), respectively, several nalidixic acid resistant mutants were selected from lipopolysaccharide (LPS) rough strains of Salmonella Gallinarum that escaped from fatal infection of a LPS-binding lytic bacteriophage. A non-virulent and immunogenic vaccine strain of Salmonella Gallinarum, SR2-N6, was established through in vivo pathogenicity and protection efficacy tests. SR2-N6 was highly protective against Salmonella Gallinarum and Salmonella Enteritidis and safer than Salmonella Gallinarum vaccine strain SG 9R in the condition of protein-energy malnutrition. Thus, SR2-N6 may be a safe and efficacious vaccine strain to prevent both fowl typhoid and paratyphoid.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.147-155
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• 2007

We investigated the safety, immunogenicity and protectivity of mix-crude outer membrane protein (cOMP) vaccine against salmonellosis in animals. The mix-cOMP vaccine was extracted from Salmonella enterica serovar Typhimurium (ST) and Salmonella enterica serovar Enteritidis (SE) and Salmonella enterica serovar Braenderup (SB) isolated from pigs. The mix-cOMP vaccine gave significantly higher antibody response than ST-bacterin and ST-cOMP vaccine in guinea pigs. The survival rates of mix-cOMP vaccinated groups showed significantly higher (100%) than those (0-20%) of unvaccinated control group, challenged with 3 species of Salmonella (ST, SE and SB) in mice. Vaccinated groups in pigs showed reduction of clinical signs, increase of average weight gains, decrease of bacterial recovery rates, compared with unvaccinated groups. Especially, the survival rates (100%) of vaccinated groups in chickens showed higher than that (0%) of unvaccinated group. Based on these results, we suggest that the mix-cOMP Salmonella vaccine developed in this study will be effective for the protection against Salmonellosis caused by the various serotypes Salmonella species in animals.

• Journal of Life Science
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• v.11 no.4
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• pp.385-391
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• 2001

Filamentous hemagglutinin (FHA) is considered as an essential immunogenic component for incorporation into acellular vaccines against Bordetella pertussis, the causative agent of whooping cough. Classically, antipertussis vaccination has employed an intramuscular route. An alternative approach to stimulate mucosal and systemic immune responses is oral immunization with recombinant live vaccine carrier strains of Salmonella typhimurium. An attenuated live Salmonella vaccine sgrain($\Delta$cya $\Delta$crp) expressing recombinant FHA(rFHA) was developed. Stable expressionof rFHA was achieved by the use of balanced-lethal vector-host system. which employs an asd deletion in the host chromosome to impose in obligate requirement for diaminopimelic acid. The chromosomal $\Delta$asd mutation was complemented by a plasmid vector possessing the asd$^{+}$ gene. A 3 kb DNA fragment encoding immuno dominant regionof FHA was subcloned in-frame downstream to the ATG translation initiation codon in the multicopy Asd$^{+}$ pYA3341 vector to create pYA3457. Salmonella vaccine harboring pYA3457 expressed approximately 105kDa rFHA protein. The 100% maintenance of [YA3457 in vaccine strain was confirmed by stability examinations. Additionally, a recombinant plasmid pYA3458 was constructed to overpress His(8X)-tagged rFHA in Essherichia coli. His-tagged rFHA was purified from the E. coli strain harboring pYA3458 using Ni$^{2+}$-NTA affinity purification system.>$^{2+}$-NTA affinity purification system.

• Korean Journal of Veterinary Research
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• v.49 no.2
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• pp.127-133
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• 2009

Salmonella enterica subsp. enterica serovar gallinarum (S. gallinarum) is the agent of fowl typhoid, and the 9R vaccine is a commercial live vaccine for the prevention of fowl typhoid. The aim of this study was to assess the safety and immunogenicity of different brands of S. gallinarum 9R vaccine used in commercial laying chickens in Korea. All 9R strains originated from three different brands showed the same pattern in the biochemical and serological properties, and pulsed field gel electrophoresis (PFGE) profile. But, there was a difference in rhamnose fermentaion, agglutination with Salmonella group $D_1$ antiserum and PFGE pattern between 9R vaccine strain and field S. gallinarum isolates. In laboratory and field trials for assesment of safety and immunogenicity of 9R vaccine, all of the three 9R vaccines showed the same safety in commercial laying chickens. In addition, there was a significant difference between the vaccinated and unvaccinated control groups in mortality and the re-isolation rate of the challenge strain from the tissues (p < 0.05), and no difference by the brands of 9R vaccine. The results from this study indicated that all three different brands of S. gallinarum 9R vaccine showed highly protection against mortality and organ invasion in commercial laying chickens exposed to virulent strains of S. gallinarum.

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.21-28
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• 2011

Salmonella Enteritidis (SE) has been a major causative agent of food-borne human disease due to consumption of contaminated eggs and poultry meat. To prevent SE infection in poultry, and therefore minimize human infections, vaccination with either killed or live SE vaccine is suggested. We evaluated a newly developed killed bacterin using a representative SE isolate in Korea. Among pool of SE isolates, two highly virulent isolates (the one isolate from chicken, the other from human) were selected by measuring mortality in mouse and chickens administered. The chickens were injected intramuscularly with killed vaccine and were challenged with highly virulent SE strain 3 week after vaccination. The recovered colony count (cfu/g) of spleen and cecal content in the vaccinated groups was reduced compared with those of the unvaccinated control group. The antibody level in the vaccinated groups was higher at 3 week post vaccination. These results indicate that vaccination with killed vaccine was effective in preventing the infection of virulent SE. Further study for a large number of layers should be needed for the effect of egg production, SE shedding in feces, persistence of antibody level.

• Korean Journal of Veterinary Research
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• v.53 no.1
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• pp.43-48
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• 2013

Commercial bivalent killed Salmonella vaccine Salenvac-T has been used in several countries in order to prevent salmonellosis with Salmonella enterica serovars Enteritidis (SE) and Typhimurium (ST) in poultry. However, this vaccine has not been used in poultry farms in South Korea. In this study, we evaluated the efficacy of Salenvac-T vaccine to protect against the challenge of virulent SE and ST, and the effect of the vaccine on egg production and mortality in layer hens. The colonization of liver, spleen and cecum with challenged SE and ST was reduced in vaccinated chickens compared with that of unvaccinated control group. The twice vaccination with Salenvac-T induced elevated antibody responses against both SE and ST detected by enzyme-linked immunosorbent assay (ELISA). The higher average hen-day production was observed in the vaccinated layer hens than in the unvaccinated layer hens without significance. The average mortality was lower in the vaccinated layer hens during the experiment period. The antibody responses to both SE and ST were persistently detected in the vaccinated layers. In summary, vaccination with Salenvac-T reduces colonization of internal organs and induces good antibody responses, thereby results in higher performance and lower egg contamination with SE and ST in layer hens.

• Korean Journal of Veterinary Research
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• v.53 no.3
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• pp.163-167
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• 2013

Avian pathogenic Escherichia coli (APEC) are known to cause extraintestinal disease in poultry, leading to substantial losses in the industry. IutA, iron-regulated aerobactin receptor is firmly associated with APEC. To assess the potential of IutA to induce protective immune responses, attenuated Salmonella Typhimurium strain expressing IutA was constructed and administered orally to BALB/c mice. The IutA-specific immune responses were measured with sera, vaginal and fecal samples by an enzyme-linked immunosorbent assay. We found that the Salmonella-IutA vaccine induced significantly higher immune responses as compared to the control inoculated with the attenuated S. Typhimurium containing the plasmid only. The IutA-specific immune responses were increased by second immunization at third week after initial immunization, whereas triple immunization induced lower immune responses than those induced by the double immunization. The Salmonella-IutA vaccine induced a nature of immunity biased to the Th1-type, as judged by the ratio of IutA-specific IgG isotypes (IgG2a/IgG1). Overall, these results suggest that the Salmonella-IutA vaccine appear to be suitable candidate for a vaccine against APEC.

• Korean Journal of Veterinary Research
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• v.53 no.4
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• pp.211-216
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• 2013

This study was focusing on evaluating the protection of polyphosphate kinase (ppk) deleted and/or temperature-sensitive (ts) Salmonella Enteritidis (SE) as an attenuated vaccine in chickens. We constructed SEppk, SEts and SEppk::ts mutants and screened those mutants by growth capability in vitro, protection study in mice model and antibody response in chickens. Among the mutants, SEppk::ts-3 was selected because it showed higher growth capability, good protection against highly virulent SE in mice model, and good antibody response in chickens. SEppk::ts-3 also showed good protection against highly virulent SE isolate because it decreased colonization of virulent SE challenge strain in spleen, liver and cecum compared with the non-vaccinated control. The SEppk::ts-3 mutant showed cross-protection against S. Gallinarum (SG) challenge although the its cross-protection rate was a little lower than that of SG9R, a commercial vaccine against SG infection. To use for live attenuated vaccine in chickens, it should further be characterized.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.303-314
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• 2023

Protective efficacy of trivalent Salmonella inactivated vaccine containing Chlorhexidine-inactivated S. Enterltidis (SE), S. Typhimurium (ST), and S. Gallinarum (SG) strains, was evaluated in this study. A total of 70 brown nick layers were divided into 7 groups, A to G, containing 10 hens per group. All hens in groups B to D were intramuscularly immunized with approximately 7×10⁸ cells (3×10⁸ cells of SE+1×10⁸ SE+1×10⁸ cells of ST+3×10⁸ cells of SG) of the trivalent vaccine in 0.5 mL of PBS. All chickens in groups E to G were injected with sterile PBS. All hens of groups B and E, groups C and F, and groups D and G were orally challenged with approximately 2 ×10⁹ CFU of wild-type SE, ST, and SG, respectively. Serum IgG titers and CD3⁺CD4⁺ T-cells, and CD3⁺CD8⁺ T-cells levels of groups B to D significantly higher than those of group A. In addition, all animals in groups A to C, E and F showed no clinical symptoms and survived after the virulent challenges, whereas one chicken in group D died and all chickens in group G died following the challenge. The protection against wild-type SE and ST in liver, spleen, cecum, and cloaca of groups B and C chickens was significant effective as compared with those in groups E and F. These indicate that the trivalent inactivated vaccine can be an effective tool for prevention of Salmonella infections by inducing robustly protective immune responses and cellular immune response in chickens.

• IMMUNE NETWORK
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• v.10 no.1
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• pp.5-14
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• 2010

Background: There have been several reports describing the capability of ginseng extracts as an adjuvant. In this study, we tested if ginsan, a polysaccharide extracted from Panax ginseng, was effective in enhancing antibody response to orally delivered Salmonella antigen. Methods: Ginsan was treated before oral salmonella antigen administration. Salmonella specific antibody was determined by ELISA. mRNA expression was determined by RT-PCR. Cell migration was determined by confocal microscopy and flow cytometry. COX expression was detected by western blot. Results: Ginsan treatment before oral Salmonella antigen delivery significantly increased both secretory and serum antibody production. Ginsan increased the expression of COX in the Peyer's patches. Various genes were screened and we found that CCL3 mRNA expression was increased in the Peyer's patch. Ginsan increased dendritic cells in the Peyer's patch and newly migrated dendritic cells were mostly found in the subepithelial dome region. When COX inhibitors were treated, the expression of CCL3 was reduced. COX inhibitor also antagonized both the migration of dendritic cells and the humoral immune response against oral Salmonella antigen. Conclusion: Ginsan effectively enhances the humoral immune response to orally delivered antigen, mediated by CCL3 via COX. Ginsan may serve as a potent vaccine suppliment for oral immunization.