• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.191-199
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• 2002

In this study, eight primers were used to detect genetic variability and phylogenetic relationships among the eighteen Salmonella strains by the arbitrary-primed PCR(AP-PCR) techniques. Five strains of Salmonella typhimurium, four strains of S entertidis, three strains of S choleraeuis, three strains of S gallinarum and three strains of S pullorum were typed by AP-PCR. The number of AP-PCR bands detected per each primer varied from 39 to 52, with an average of 43.6. A total of 349 AP-PCR bands were generated and among them, 185 bands(53.0%) were polymorphic. Among the primers, GEN 703 and GEN 708 primer showed a high level of polymorphism with 0.682 and 0.676, respectively. But GEN 603, GEN 604 and GEN 607 primer showed a low level of polymorphism with 0.404, 0.460 and 0.472, respectively. Therefore, the these primers will be the most effective for AP-PCR analysis of Salmonella strains. The level of polymorphism of S typhimurium CU 2001(0.77) was similar to that of S typhimurium CU 2002(0.77) and lower than those of other strains such as S typhimurium CU 2003(0.63), S typhimurium ATCC 14028(0.50) and S typhimurium CU 2004(0.43). The level of polymorphism of S enteritidis ATCC 13076(0.83) was similar to that of S enteritidis CU 2005(0.83) and lower than those of other strains such as S enteritidis CU 2006(0.63) and S enteritidis CU 2007(0.58). The level of polymorphism of S choleraeuis CU 2009(0.67) was similar to that of S choleraeuis CU 2010(0.67) and higher than those of other strains such as S choleraeuis CU 2008(0.53). The level of polymorphism of S gallinarum CU 2011(0.70) was similar to that of S gallinarum CU 2012(0.70) and higher than those of other strains Such as S gallinarum ATCC 9184(0.60). The level of polymorphism of S pullorum CU 2013(0.80) was similar to that of S pullorum CU 2014(0.80) and higher than those of other strains such as S pullorum No 11(0.53). Therefore, the AP-PCR analysis will be used a powerful tool for estimating genetic variation and phylogenetic relationships among Salmonella strains.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.765-769
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• 2005

The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1689-1694
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• 2008

The ability to detect Salmonella spp. is essential in the prevention of foodborne illness. This study examined a Salmonella spp. detection method involving the application of immunomagnetic separation and immunoliposomes (IMS/IL) encapsulating sulforhodamine B (SRB), a fluorescent dye. A quantitative assay was conducted by measuring the fluorescence intensity of SRB that was produced from an immunomagnetic bead-Salmonella spp.-immunoliposome complex. The results indicated detection limits of $2.7{\times}10^{5}$ and $5.2{\times}10^{3}$ CFU/ml for Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterka subsp. enterka serovar Typhimurium (S. Typhimurium), respectivley. The signal/noise ratio was improved by using 4% skim milk as a wash solution rather than 2% BSA. In addition, higher fluorescence intensity was obtained by increasing the liposome size. Compared with the conventional plating method, which takes 3-4 days for the isolation and identification of Salmonella spp., the total assay time of to h only including 6 h of culture enrichment was necessary for the Salmonella detection by IMS/IL. These results indicate that the IMS/ IL has great potential as an alternative rapid method for Salmonella detection.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.185-189
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• 2010

An electronic nose was used to identify Salmonella contamination on beef based on odors. To detect pathogen contamination of beef, $100{\mu}L$ of $10^5CFU/g$ Salmonella Enteritidis or Salmonella Typhimurium cell suspensions were spiked onto 5 g beef sirloin samples in individual vials. Odor changes over time were then measured and analyzed using an electronic nose system to identify pathogen contamination. In principle, the electronic nose system based on a surface acoustic wave (SAW) detector produced different frequency responses depending on the time and amount of each chemical. Multivariate analysis of the odor data was conducted to detect Salmonella contamination of beef. Salmonella odors were successfully distinguished from uncontaminated beef odors by principal component analysis (PCA). The PCA results showed that Salmonella contamination of beef could be detected after 4 h of incubation. The numbers of cells enumerated by standard plate count after 4 h of inoculation were $2{\times}10^6CFU/g$ for both Salmonella Enteritidis and Salmonella Typhimurium.

• Journal of Dairy Science and Biotechnology
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• v.36 no.4
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• pp.208-219
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• 2018

Emergence of drug resistant strains of Salmonella enterica threatens milk processing and related dairy industries, thereby increasing the need for development of new anti-bacterials. Developments of antibacterial drugs are largely aimed to target the bacterial envelope, but screening their efficacy on bacterial envelope is laborious. This study presents a potential biosensor for envelope-specific stress in which a gfp reporter gene fused to spy gene encoding a periplasmic chaperone protein Spy (spheroplast protein y) that can sense envelope stress signals transduced by two major two-component signal transduction systems BaeSR and CpxAR in Salmonella enterica serovars Enteritidis and S. Gallinarum. Using spy-gfp operon fusions in S. Enterititis and S. Gallinarum, we found that spy transcription in both serovars was greatly induced when Salmonella cells were forming the spheroplast and were treated with ethanol or a membrane-disrupting antibiotic polymyxin B. These envelope stress-specific inductions of spy transcription were abrogated in mutant Salmonella lacking either BaeR or CpxR. Results illustrate that induction of Spy expression can be efficiently triggered by two-component signal transduction systems sensing envelope stress conditions, and thereby suggest that monitoring the spy transcription by spy-gfp operon fusions would be helpful to determine if developing antimicrobials can damage envelopes of S. Enteritidis and S. Gallinarum.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.1
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• pp.78-87
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• 2017

The objective of this study was to investigate the effects of various washing waters on the quality and safety characteristics of eggs during storage. Eggs were washed with tap water, 100 ppm of sodium hypochlorite, or 30 ppm of slightly acidic electrolyzed water and stored at $10^{\circ}C$ and $20^{\circ}C$. Effects of various washing waters on reduction of Salmonella Enteritidis and aerobic plate counts and survival of S. Enteritidis on egg shells were also analyzed at $10^{\circ}C$ and $20^{\circ}C$ for 25 days. As an index of quality, haugh unit, weight reduction, and pHs of egg white and egg yolk were measured. Reduction percentages of haugh unit and weight were higher at $20^{\circ}C$ than at $10^{\circ}C$. Egg qualities were less affected by tap water, slightly acidic electrolyzed water, and sodium hypochlorite, regardless of storage temperature. The greatest reductions in aerobic plate counts and S. Enteritidis were observed with slightly acidic electrolyzed water. The level of S. Enteritidis on egg shells gradually decreased during 20 days of storage at both $10^{\circ}C$ and $20^{\circ}C$, whereas S. Enteritidis survived longer at $20^{\circ}C$ than at $10^{\circ}C$. S. Enteritidis was not detected in eggs at $10^{\circ}C$, 2.13 log CFU/g of S. Enteritidis was detected in eggs washed with sodium hypochlorite after 20 days of storage at $20^{\circ}C$, indicating that S. Enteritidis penetrated into the egg shell during storage at $20^{\circ}C$. In conclusion, slightly acidic electrolyzed water increased microbial reduction and least affected quality of washed eggs. Thus, slightly acidic electrolyzed water can be recommended for washing of graded eggs, at retail markets.

• Natural Product Sciences
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• v.11 no.3
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• pp.160-164
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• 2005

The effects of Cymbopogon citratus essential oil (Lemongrass oil) and its main component, citral (84.30%), on antibiotic-susceptible and -resistant strains of Salmonella enteritidis and S. typhimurium were assessed. C. citratus oil and citral significantly inhibited all strains of the two Salmonella species examined, with minimum inhibiting concentrations (MICs) ranging from 0.5 mg/ml to 8.0 mg/ml. The combined effects of C. citratus oil and citral (84.30%) were evaluated using a checkerboard microtiter assay. Essential oil fractions of C. citratus and citral exhibited strong synergistic or additive effects with streptomycin or kanamycin against S. typhimurium strains with fractional inhibitory concentration (FIC) indices in the range of 0.28 to 1.00. In conclusion, a combination of streptomycin and lemongrass oil or its main component, citral, may be useful for reducing the minimum effective dose of antibiotic required for the treatment of resistant S. typhimurium infections.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.584-587
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• 2000

The invasion genes from Salmonella typhimurium were identified by the construction of a cosmid library and subcloning genes into a plasmid vector, pGEM-7Z. The 4.65 kb fragment of the invasion-conferring genomic region of the subclone, pSV6235 was sequenced in both direction. The three open reading frames, which were located at downstream of a promoter region, were designated as sir (Salmonella invasion region)A coding for the 36 amino acids, sirB coding for the 132 amino acids and sirC for the 82 amino acids, respectively. Interesingly, the genomic region of pSV6235 was highly homologous to Yersinia enterocolitica genomic DNA for a high pathogenicity island and Salmonella enteritidis insertion element IS1351 and IS200 DNA. These results show that there could be a significant relationship between S. typhimurium, Y. enterocolitica and S. enteritidis with respect to horizontal evolution process and acquisition of virulence determinants by means of transposon, plasmid or bacteriophage.

• 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.

• Food Science of Animal Resources
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• v.36 no.1
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• pp.100-108
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• 2016

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO₂ gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO₂ each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry.