• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1731-1739
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• 2012

In this study, seven strains isolated from mustard leaf kimchi were screened for their tolerance to simulated gastric and bile juices, the adhesive properties to Caco-2 cells, and the inhibition ability of Salmonella Typhimurium ATCC 29631 adhesion. Lactobacillus acidophilus GK20, Lactobacillus paracasei GK74, and Lactobacillus plantarum GK81, which were resistant to bile as well as gastric juices, possessed high bile-salt hydrolase (BSH) activity towards both sodium glycocholate and sodium taurocholate. The strongest in vitro adherence of $53.96{\pm}4.49%$ was exhibited by L. plantarum GK81 followed by L. acidophilus GK20 with adhesion levels of $40.72{\pm}9.46%$. The adhesion of these strains was significantly (p < 0.05) reduced after exposure to pepsin and heating for 30 min at $80^{\circ}C$. Addition of $Ca^{2+}$ led to a significant (p < 0.05) increase of the adhesion of L. acidophilus GK20, but the adhesion ability of L. plantarum GK81 was not different from the control by the addition of calcium. In the competition and exclusion experiment, the adhesion inhibition of S. Typhimurium by L. plantarum GK81 strain was much higher than the other strains. Moreover, the exclusion inhibition of S. Typhimurium by L. acidophilus GK20 was considerably high, although the inhibition activity of this strain was lower than L. plantarum GK81.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.109-113
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• 2013

In a previous study, a relatively high dose of gamma radiation (1 kGy) did not fully induce typical SOS genes such as sulA, recA, recN, and din in Salmonella Typhimurium (S. Typhimurium) (Lim et al. 2008, Gene expression profiles following high-dose exposure to gamma radiation in Salmonella enterica serovar Typhimuium. J. Radiat. Ind. 3:111-119). In this study, we examined changes in the transcriptional repertoire of S. Typhimurium after a dose of 10 Gy using DNA microarrays. It was found that more than half (~65%) of the 26 up-regulated genes belong to the SOS regulon: ten genes are typical SOS genes, and seven genes are Salmonella prophage genes, which are known to be activated by LexA cleavage. Among 29 down-regulated genes, the function of five genes with the most decreased expression is associated with carbohydrate transport and energy production. This suggests that upon exposure to gamma radiation cells may cease growing by reducing the metabolic activity, and repair DNA damage using a DNA repair system such as the SOS response system. The difference in expression of the SOS genes between a high (1 kGy) and low (10 Gy) dose of radiation shows the possibility that cells may opt for one of multiple regulatory circuits in response to the specific gamma radiation dose.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.468-472
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• 1995

Substantial amount of caryophyllene oxide (CPO) is present in the essential oils of traditionally-used folk medicinal plants and herbal spices. The CPO, produced via chemical and/or enzymatic reaction of caryophyllene (CP), has largely being used as a flavoring component and exhibited a variety of biological activities. Now, we report the antimutagenic activity of CPO determined by Ames's preincubation test. S-9 fraction was prepared from the liver of rats treated with Arochor 1254. Anatoxin $B_1\;(AFB_1)$ and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) were used as mutagens. Reduction of mutagenicity of $AFB_1$ or IQ for S. typhimurium TA98 and TA100 by CPO was found to be a dose-dependant manner. CPO (500 ${\mu}g/plate$) reduced mutagenicity of AEB1 for S. typhimurium TA98 and TA100 to 89% and 71%, respectively. For IQ, similar results were observed against S. typhimurium TA98 and TA100, resulting in the inhibition percentage of 77% and 51%, respectively. CP also reduced mutagenicity of AEB1 and IQ for S. typhimurium TA98 and TA100, but the reduction rate was somewhat lowered relative to that of CPO. These results indicate that CPO could be developed as a potent antimutagenic flavoring agent.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.270-270
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• 2002

Pathogenic Salmonella typhimurium can invade the intestinal epithelium and cause a wide range of diseases including gastroenteritis and bacteremia in human and animals. To identify the genes involved in the infection, the invasion determinant was obtained from S. typhimurium 82/6915 and was subcloned into pGEM-7Z. A subclone DHl (pSV6235) invaded HEp-2 and Chinese hamster ovary epithelial cells and contained a 4.4 kb fragment of S. typhimurium genomic region. Compared with the host strain E. coli DHl, the subclone DHl (pSV6235) invaded cultured HEp-2 and Chinese hamster ovary cells at least 75- and 68-fold higher, respectively. The invasion rate of E. coli DHl for the cells significantly increased by harbouring the genomic region derived from pathogenic S. typhimurium 82/6915.

• Journal of Animal Science and Technology
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• v.55 no.6
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• pp.545-549
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• 2013

The optimal conditions for applications of an atmospheric pressure plasma (APP) jet for the inactivation of Salmonella Typhimurium in chicken breast and pork loins were investigated. APP jet treatment for 10 min (versus 5 minutes) showed a higher inactivation of S. Typhimurium in an agar plate, with the best effect at a distance of 20 mm. A treatment on both sides (both-side treatment) for 2.5 + 2.5 min showed a greater inhibition on S. Typhimurium growth compared to single-side treatment for 5 min, with reduction levels of 0.66 log CFU/g in chicken breast and 1.33 log CFU/g in pork loin, respectively. However, there was no significant difference between single-side treatment for 10 min and both-side treatment for 5 + 5 min in chicken breasts and pork loin samples. In conclusion, APP jet treatment conditions, including distance, time, and direction, may affect the inactivation efficiency of S. Typhimurium. In this experiment, distance of 20 mm and both-side treatment were the best conditions. Therefore, the optimal APP jet treatment conditions were evaluated to maximize its practical efficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.57-76
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• 1993

Phototoxicity is a complex phenomenon which may involve photochemical reaction and biological response mechanism. This complexicity and iii mal protecting tendency has led to the development of various in-vitro approaches as sensitive, alternative test to the in-vivo phototoxicity test. In this study, we investigated not only the sensitivity of two microorganism, (C. albicans and 5. typhimurium TA 98 about UV) but also a correlation between in-vitro and in-vivo phototoxicity test using UV A and 1 Furthermore, we studied the effect of irradiation method which were as follows 1) irradiate to material and microorganism, simultaneously 2) irradiate to only material 3) irradiate to material and microorganism, respectively In each irradiation method, it showed no significant difference, However we were able to observe the more sensitive phototoxicity in S. typhimurium TA 98 than C. albicans, and the results of in-vitro test using 5. typhimurium TA 98 had a good correlation with those of in-vivo test.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.441-447
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• 1998

This study was performed to investigate the changes of amount of S. typhimurium during cooking processes using pork and japchae (a Korean food which is made from meat, vegetables and noodles), and to support a practical application to develop a hazard analysis critical control point (HACCP) model. The pork was purchased in a retail shop, cut ($0.5\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm$, 25 g), tested for Salmonella contamination (results: negative), inoculated with S. typhimurium ($10^{7}\;CFU/g$), then treated in various conditions related to cooking. Mter thawing for 24 hours in various conditions, the number of S. typhimurium was increased to $10^{10}\;CFU/g$ at a refrigerated temperature ($4~10^{\circ}C$), and to $10^{21}\;CFU/g$ at room temperature ($22~29^{\circ}C$). Mter thawing in a microwave oven for 40 seconds, the number of S. typhimurium increased to $10^{8}\;CFU/g$. During the thawing period, the number of S. typhimurium increased over time. At the refrigerated temperature, the number of the bacteria was $10^{10}\;CFU/g$ after 24 hours, $10^{13}\;CFU/g$ after 48 hours, and $10^{20}\;CFU/g$ after 72 hours. At room temperature the number of bacteria reached $10^{11}\;CFU/g$ in 2 hours, $10^{15}\;CFU/g$ in 4 hours, $10^{16}\;CFU/g$ in 8 hours, $10^{18}\;CFU/g$ in 12 hours, and $10^{21}\;CFU/g$ in 24 hours. Mter cooking in a frying pan (150{\pm}7^{\circ}C$) for 3 minutes, the bacterial count was $10^{16}\;CFU/g$. After cooking in hot water for 20 minutes, the bacterial count was $10^{7}\;CFU/g\;at\;60^{\circ}C,\;10^{6}\;CFU/g\;at\;63^{\circ}C,\;and\;10^{4}\;CFU/g\;at\;65^{\circ}C$. The fried pork was mixed with cooked vegetables, noodles, sesame oil, sesame seeds, and seasonings to make Korean japchae. This process took $10{\pm}2$ minutes. The bacterial count in the japchae increased to $10^{7}\;CFU/g$ from the count of $10^{6}\;CFU/g$ of the fried pork before it was mixed with the other ingredients. These results indicate that the amount of S. typhimurium is effected by various different cooking processes. This study can suggest that pork should be cooked in water at over $65^{\circ}C$ for 20 minutes in order to prevent food poisoning, if the pork is contaminated with S. typhimurium. The presence of S. typhimurium in the raw pork is identified in an HA for japchae, and the primary CCP for japchae is inadequate cooking (cooking method and time/temperature). We need to standardize time-temperature-size and amount of pork in cooking japchae, because pork is usually cooked in ordinary frying pans when we make this food.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.215-219
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• 2010

This study was undertaken to investigate the mutagenicity and antimutagenicity of Acanthopanax koreanum Nakai. Antimutagenic study on extract of A. koreanum was studied using the test with Salmonella typhimurium TA100, TA98. And mutagenicity study was studied using the test with S. typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvr A. A. koreanum was negative in Ames test with S. typhimurium and E. coli with or without S-9 mixture. Test substances of $5000\;{\mu}g/{\mu}l$, $2500\;{\mu}g/{\mu}l$ and $600\;{\mu}g/{\mu}l$ of A. koreanum extracts were chosen via toxicity test. Ames test was performed on positive control group, experimental group and negative control group in the presence of the metabolic activation system and metabolic non-activation system. As a result, there was no coherent increase and reverse mutation in all concentrations. Therefore, A. koreanum does not cause reverse mutation. In addition, A. koreanum showed strong antimutagenic activities in S. typhimurim TA100 and TA98. In conclusion, A. koreanum root may be an excellent antimutagenic agent.

• Korean Journal of Veterinary Research
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• v.57 no.4
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• pp.235-243
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• 2017

Salmonella (S.) Typhimurium is highly contagious, and its infection may rapidly spread within pig populations of herd. According to the survey (1,191 pigs) from 2003 to 2012, 155 pigs (13.0%) were diagnosed as salmonellosis in Jeju. Major porcine salmonellosis cases (88.4%) were concentrated in 4- to 12-week-old weaned pigs, but 6 pigs (3.9%) under 4 weeks old were also diagnosed. Based on the histopathologic examinations, ulcerative enteritis (63.9%) in the large intestine and/or paratyphoid nodules formation (57.4%) in the liver were most prevalent lesions in porcine salmonellosis. Single infection of S. Typhimurium and mixed infection with more than 2 pathogens were detected in 38 (24.5%) and 117 (75.5%) in pigs, respectively. Co-infections of Porcine reproductive and respiratory syndrome virus and Porcine circovirus type 2 were very common in porcine salmonellosis in Jeju and detected in 84 (54.2%) and 59 (38.1%) pigs, respectively. Based on the serotyping tests using 41 bacterial isolates, S. Typhimurium and S. Rissen were confirmed in 39 (95.1%) and 2 (4.9%) cases, respectively.

• Korean Journal of Microbiology
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• v.20 no.1
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• pp.11-20
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• 1982

A study was undertaken to examine the effect of curing agents on the stability, curing and segregation of R plasmid pSL100. And also the stability, transfer frequency, and recombination of its segregants obtained from curing agent treatment were studied. Ethidium bromide, acridine orange, and mitomycin-C were used as curing agent. The results obtained were as follows ; 1. The curing agent ethidium bromide, acridine orange, and mitomycin-C were not effective for curing the multiple antibiotic resistant determinant of pSL100 in Salmonella typhimurium and Escherichia coli. However, they induced plasmid segregation with high frequency in S.typhimuruim LT-2strains. TcApSmCm, TcSmCmKm, TcApCm, TcAp, TcKm, Tc segregants were obtained. 2. The resistant markers of the segregents were transferred to S.typhimurium LT-2 strains with high frequencies whereas they were transferred to E.coli K-12 only with low frequencies. 3. The transconjugants obtained from conjugation between two different S.typhimurium segregants were similar to the phenotype of the original R factor pSL100 and the resistant markers were transferred to the S.typhimurium LT-2 or E.coli strain with equal frequencies, indicating that they are recombinants. 4. The transconjugants obtained from conjugation between pSL100 segrgants and pKM101, or pBR322 possessed the resistant markers of the two parental plasmids and they were transferred to both S.typhimurium and E.coli K-12 strains with the same frequencies and maintained stably, suggesting that they are also recombinants. 5. The recombinant pSL100 could be also obtained in rec A-strains of E.coli, suggesting that the gene function of rec A is required for the recombination of pSL100 segregants in E.coli.