• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.164-166
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• 2001

To examine the characteristics of the recombinant thin aggregative fimbriae of Salmonella, the AgfA subunit gene was amplified from Salmonella enteritidis using a PCR. The maltose binding protein (MBP)-AgfA fusion protein was overproduced in E. coli and purified. The secondary structure of AgfA was then elucidated from the difference CD spectra. An estimation of the secondary structure of AgfA using the self-consistent method revealed a mostly ${\beta}-sheet$ structure.

• Journal of Life Science
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• v.32 no.1
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• pp.36-43
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• 2022

Mucosal immunity is a well-designed defense system that builds precise and dynamic relationships against pathogens, and the gastrointestinal tract is the most important organ with this system, acting as a guardian at the forefront of its activity. Salmonella spp. cause food poisoning, entering the body orally and mainly invading the Peyer's patches of the small intestine. Although Salmonella strains share similar mechanisms for inducing innate immunity, different serotypes may have different effects on the intestinal mucosa due to host specificities and pathogenicity. In this study, we evaluated the effects of Salmonella enteritidis infections in mouse intestine and observed significantly reduced dose-dependent survival rates in a challenge test. Flow cytometry data showed no significant differences in intestinal immune cell populations, although histology indicated increased mucin production and decreased goblet cell counts in the Salmonella-treated groups. Furthermore, Claudin expression was significantly decreased in the samples with Salmonella. To investigate the relationship between S. enteritidis infection and inflammatory response, dextran sodium sulfate (DSS) was administered after infection and the results indicate lower survival rate after DSS treatment. In conclusion, we were able to identify the optimal concentration of S. enteritidis to modulate the intestinal mucosal immunity of mice and inflammatory response.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2151-2155
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• 2017

Bacteriophages have gained substantial attention as biocontrol and biorecognition agents, substituting antibodies. In this study, a Salmonella Enteritidis-specific bacteriophage, KFS-SE1, was isolated, identified, and characterized. This Siphoviridae phage infects S. Enteritidis with high specificity. This phage is highly stable under various pH (5-11), temperature ($4-60^{\circ}C$), and organic solvent conditions. The KFS-SE1 genome consisted of 59,715 bp with 73 predicted open reading frames and 57.14% GC content; it had a complete set of genes required for phage reconstruction. Comparative phylogenetic analysis of KFS-SE1 revealed that it was very similar to the other Salmonella phages in the Siphoviridae family. These characteristics suggest that KFS-SE1 with its high specificity and host lysis activity toward S. Enteritidis may have various potential applications.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.243-253
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• 2001

Forty-five Salmonella typhimurium isolates were encountered 8 phage types in which DT197 and U302 were the predominant types. The DT104 type which was first found from pig in Korea, and was resistant to chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim, tetracycline, gentamicin and nalidixic acid. Twenty-two S enteritidis isolates were encountered 5 phage types in which PT4 were the representative (predominant). S enteritidis isolates were susceptible to all antimicrobial agents. As a result of PFGE analysis for S typhimurium and S enteritidis, PFGE patterns was better than phage typing in discriminating of strains. PFGE patterns were not in accord with phage type even though some strain had the same phage types.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.430-434
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• 2003

In vivo antagonistic effect of Lactobacillus helveticus CU 631 and Lactobacillus spp. against typical enteritis causing pathogen Salmonella enteritidis KU 101 have been determined, which showed an increase in survival rate and the decline in viable cell numbers of pathogen in liver and spleen at sacrifice. A signifcant difference in the antagonistic effect against KU 101 were observed, which was species and/or strain dependent of Lactobacillus (p<0.01), the survival rate of the mice in the Salmonella infection by feeding L. helveticus CU 631 has been shown to be 157%, whereas those of L. rhamnosus GG ATCC 53103, L. acidophilus ATCC 4356, L. johnsonii C-4 were 137%, 132%, 119% respectively on the basis of lactobacilli non-associated control KU101 fed mice to be 100%. Viable cells of S. enteritidis KU101 in the liver and in the spleen at sacrifice were decreased in Lactobacillus spp. fed group with no significant difference. The higher level of total secretory IgA concentration in the intestinal fluid of lactobacilli fed mice than control mice have been observed. In vitro antagonistic activity of Lactobacillus spp. against KU101 have been determined, a prominent antagonistic activity of CU 631 against KU 101 were demonstrated.

• 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.32 no.3
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• pp.369-376
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• 1992

This paper dealt with plasmid DNA profile in 98 Salmonella(S) isolated from pigs and cattle sources in Taegu, Gyeongbook and Gyeongnam during the period from 1984 to 1987. Also we were studied for restriction enzyme analysis of the plasmid DNA, and mouse infection, Sereny test and normal setum resistance test in guinea pig for S typhimurium and S enteritidis harbored or cured 60 megadalton(Md) plasmid and 36 Md plasmid, respectively. Of the 13 Salmonella isolated from cattle, 7 Salmonella harbored one or more plasmids and molecular sizes of the large plasmids were 60 Md for S typhimurium and 36 Md for S enteritidis. Of the 85 Salmonella isolated from pigs, 47 Salmonella were confirmed as being one or more plasmids, and all the S typimurium stains harbored 60 Md plasmid. In enzyme digestion with 8 types of restriction endonuclease for 60 Md plasmid DNA of S typhimurium, cleavage patterns were varied to enzymes, and the DNA was segmented into 4 to 15 fragments. In restriction enzyme analysis of 36 Md plasmid DNA obtained from four strains of S. enteritidis, the DNA showed the same cleavage patterns obtained with Eco RI, Hind III and Bam H I, and was segmented into 3 to 5 fragments. In virulence for mice by measuring the 50% lethal dose ($LD_{50}$), the $LD_{50}$ values obtained for 60 Md virulence-associated plasmid harbored strains of S typhimurium and 36 Md virulence-associated plasmid of S enteritidis were up to $10^4$-fold lower than the values obtained for the plasmid-cured strains of the same serotype. Only the plasmid harbored strains were resistant to the bactericidal activity of 90% guinea pig serum, and only they gave positive responses in sereny test. We suggested that their plasmid DNA might be associated with virulence for mice.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.526-531
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• 2006

Minimum inhibition concentration(MIC), growth inhibition activity, and colony forming inhibitory activity of grapefruit seed extract against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Escherichia coli, Salmonella enterifidis and Serratia marcescens were tested. MIC of grapefruit seed extract against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis and Serratia marcescens was 12.5, 12.5, 12.5, 50, 50, 100ppm, respectively. Growth inhibition concentration of grapefruit seed extract against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis and Serratia marcescens was below 1.0, 6.25, below 1.0, 6.25, 25, 25ppm, respectively. Colony forming inhibitory activity of grapefruit seed extract against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis and Serratia marcescens was 93.9, 94.0, 99.9, 4.4, 82.7, 86.4%, respectively. Colony forming inhibitory activities of grapefruit seed extract against Gram positive bacteria were higher than that against Gram negative bacteria.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.288-295
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• 2015

Salmonella enterica serovar Enteritidis is the predominant agent causing salmonellosis in chickens and other domestic animals. In an attempt to identify antigenic S. Enteritidis outer membrane proteins (OMPs) that may be useful for subunit vaccine development, we established a proteomic map and database of antigenic S. Enteritidis OMPs. In total, 351 and 301 spots respectively from S. Enteritidis strain 270 and strain 350 were detected by two-dimensional gel electrophoresis. Fifty-one antigen-reactive spots were detected by antisera on two-dimensional immunoblots and identified as 12 specific proteins by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. OmpA and DNA starvation/stationary phase protection protein (Dps) were the most abundant proteins among the identified OMPs, comprising 22 and 12 protein species, respectively. Interestingly, we found that the Dps of S. Enteritidis is also antigenic. OmpW was also verified to have high antigenicity. These results show that OmpA, Dps, and possibly OmpW are antigenic proteins. This study provides new insights into our understanding of the immunogenic characteristics of S. Enteritidis OMPs.

• Journal of Nutrition and Health
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• v.38 no.2
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• pp.112-116
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• 2005

This study was performed to investigate the antimicrobial effect of the Agrimonia pilosa Ledeb. extracts against food-borne pathogens. First, the Agrimonia pilosa Ledeb. was extracted with methanol at room temperatures, and fractionation of the methanol extracts from Agrimonia pilosa Ledeb. was carried out by using petroleum ether, chloroform, and ethyl acetate, and methanol respectively. The antimicrobial activity of the Agrimonia pilosa Ledeb. extracts was determined using a paper disc method against food-borne pathogens and food spoilage bacteria. The petroleum ether extracts of Agrimonia pilosa Ledeb. showed the highest antimicrobial activity against Pseudomonas aeruginosa. The synergistic effect has been found in combined extracts of Agrimonia pilosa Ledeb. and Perillae folium as compared to each extracts alone. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Agrimonia pilosa Ledeb. against Bacillus Cereus and Salmonella Enteritidis. The petroleum ether extract of Agrimonia pilosa Ledeb. showed strong antimicrobial activity against Bacillus Cereus at the concentration of 4,000 ppm. The 4,000 ppm of petroleum ether extract from Agrimonia pilosa Ledeb. retarded the growth of Bacillus Cereus more than 24 hours and Salmonella Enteritidis up to 36 hours. The petroleum ether extracts of Agrimonia pilosa Ledeb. has been shown the antimicrobial effect against Bacillus Cereus and Salmonella Enteritidis. (Korean J Nutrition 38(2): 112～116, 2005)