• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1059-1064
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• 1996

The inhibitory effects of chitosan on mutagenicity induced by 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-P-2), sodium azide (SA), 2-nitrofluorene (2-NF), and 4-nitroquinoline oxide (4-NQO) were investigated using Salmonella typhimurium reversion assay and SOS Chromotest. In Salmonella typhimurium reversion assay. Chitosan showed 24-65% of inhibitory effect against the mutagenicity of an indirect-acting mutagen, Trp-P-2. On the other hand, no inhibitory effect was observed against the mutagenicity of direct-acting mutagens (2-NF, SA). In SOS chromotest. chitosan showed 46-49% effects on SOS function induced by 4-NQO. Chitosan inhibited the mutagenicity induced by Trp-P-2 with 9-39% of inhibition rate. It was also evaluated whether inhibitory effect of chitosan is due to its bio-antimutagenic or desmutagenic action. Chitosan at high concentrations showed a bio-antimutagenicity with dose-dependent manner, but it showed a desmutagenicity at low concentrations against the mutation induced by Trp-P-2.

• Journal of Microbiology
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• v.42 no.3
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• pp.216-222
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• 2004

In a previous paper, the ogdH gene that encodes 2-oxoglutarat dehydrogenase was isolated from Salmonella typhimurium. The catalytic N-terminal region in the enzyme was found to be very specific for the Salmonella species. Therefore, the aim of the present study was to detect S. typhimurium in food sources using primers designed for OGDH-l and OGDH-2 which were based on the salmonella-specific region of the ogdH gene. A simple polymerase chain reaction (PCR) detection method was developed to detect low numbers of S. typhimurium in a chicken meat microbial consortium. Using the ogdH-specific primers under stringent amplification conditions and for gene probe analysis, fewer than 100 colony-forming units (CFUs) were detectable when pure cultures were employed. When the PCR assay was run on S. typhimurium-contaminated meat contents, only the positive meat samples containing as few as 200 CFUs reacted to the assay. The method employed for sample processing is simple and it was determined to provide a sensitive means of detecting trace amounts of S. typhimurium-specific sequences in the presence of mixed meat microbial populations. When compared with six representative intestinal gram-negative bacterial strains in foods, including Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, E. coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., S. typhimurium had a unique and distinct PCR product (796 bp). In conclusion, the two OGDH primers were found to be rapid and sensitive detectors of Salmonella spp for the PCR method.

• KSBB Journal
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• v.11 no.4
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• pp.420-430
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• 1996

One-step immuno-chromatography assay system for heat-killed Salmonella typhimurium antigens was developed. Three major components used were a glass fiber membrane (placed at the bottom of the system) with an antibody (specific to the analyse, detection antibody)-gold conjugate deposited in a dry state on the surface, a nitrocellulose membrane (middle) with an antibody (also, specific to the analyse but recognized different epitome: capture antibody) and anti-detection antibody immobilized in spatially separated areas, and a cellulose membrane (top) as absorption pad. These membranes were partially superimposed such that a wicking of aqueous solution containing sample can continuously take place through membranes. Variables that affected the system performance were the concentration of capture antibody, the location on the membrane, inert protein used for blocking of the membrane and for carrying the sample, and the concentration of the gold conjugate. Under optimal conditions, within 15 minutes after absorption of a sample solution from the bottom of the system antigen-antibody complexes of sandwich type were formed on the membrane surface area with immobilized capture antibody and a color signal was generated in proportion to the analyse concentration. The minimum do tection limit of the analyse was $1{\times}106$ Salmonella cells/mL.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1452-1459
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• 2007

The Dps protein, which is overexpressed in harsh environments, is known to playa critical role in the protection of DNA against oxidative stresses. In this study, the roles of Fur in the expression of the dps gene in Salmonella and the protection mechanisms against oxidative stress in Salmonella cells preexposed to iron-stress were investigated. Two putative Fur boxes were predicted within the promoter region of the S. typhimurium dps gene. The profile of dps expression performed by the LacZ reporter assay revealed growth-phase dependency regardless of iron-status under the culture conditions. The fur mutant, $_X4659$, evidenced a reduced level of ${\beta}$-galactosidase as compared to the wild-type strain. The results observed after the measurement of the Dps protein in various Salmonella regulatory mutants were consistent with the results acquired in the reporter assay. This evidence suggested that Fur performs a function as a subsidiary regulator in the expression of dps. The survival ability of Salmonella strains after exposure to oxidative stress demonstrated that the Dps protein performs a pivotal function in the survival of stationary-phase S. typhimurium against oxidative stress. Salmonella cells grown in iron-restricted condition required Dps for full protection against oxidative stress. The CK24 (${\Delta}dps$) cells grown in iron-replete condition survived at a rate similar to that observed in the wild-type strain, thereby suggesting the induction of an unknown protection mechanism(s) other than Dps in this condition.

• 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.

• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.247-251
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• 2016

Salmonella is one of the most common bacteria that causes heavy losses in swine industry and major causative pathogen of food poisoning in public health. Various methods for the identification of Salmonella such as Gram staining, agglutination test, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) have been used. Several studies have demonstrated that Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI TOF) Mass Spectrometry (MS) identification is an efficient and inexpensive method for the rapid and routine identification of isolated bacteria. In this study, MALDI TOF MS could provide rapid, accurate identification of Salmonella spp. from swine compared with end point PCR and real time PCR.

• Toxicological Research
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• v.14 no.3
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• pp.453-457
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• 1998

In order to evaluate the mutagenic potential of Intralipidos produced by Greenmate cooperation. We performed Salmonella typhimurium reversion assay, chromosomal aberration test on chinese hamster ovarian cells and in vivo micronucleus assay using mouse bone marrow cells. In the reverse mutation test using Salmonella typhimurium TA98 and TA100, Intralipidos did not increase the number of revertant at any of the concentration tested in this study. Intralipidos did not increase the number of cells having structural or numberical chromosome aberration in cytogenetic test. In mouse micronucleus test, no significant increase were observed in the occurrence of micornucleated polychromatic erythrocytes in ICR male mice intraperitoneally administered with Intralipidos. These results indicate that Intralipidos has no genetic toxicity under these experimental conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.539-543
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• 1992

This study was carried out to investigate the antimutagenic affect of crude and heated comfrey extract on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), benzo${(\alpha)}$pyrene (B${(\alpha)}$P) and 3-amino-1, 4-dimethyl-5H-pyri-do [4,3-b] indole (Trp-P-1). In spore rec-assay using Bacillus subtilis $H17(rec^+)$ and $M45(rec^-),$ crude comfrey extract showed strong antimutagenic effects on MNNG in the concentration of $40{\mu}l/disc$(p<0.01). In the Ames test using Salmonella typhimurium TA98 and TA100, the crude comfrey extract suppressed about 43% and 52% in the mutagenesis induced by $B{(\alpha)}P.$ However, the heated comfrey extract strongly suppressed about 75% and 76% in the mutagenesis in Salmonella typhimurium TA98 and TA100 induced by Trp-P-1(p<0.01).

• Journal of Food Hygiene and Safety
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• v.10 no.3
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• pp.133-138
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• 1995

In vitro antimutagenic activity of methanol extract from brrwn rice and its physico-chemical characteristics were investigated using Salmonella typhimurium reversion assay and SOS chromotest. Methanol extracts of brown rice were not mutagenic compared with direct and indirect, mutagenicities of 4NQO (4-nitroquinoline oxide), 2NF(2-nitrofluorene), Trp-p-1(3-Amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole), and Trp-p-2(3-Amino-1-methy-5H-pyrido-[4,3-b]indole). Antimutagenic activity against the indirect mutagenicties induced by Trp-p-1, Trp-p-2 and AFB1 (aflatoxin B1) was found in methanol extract. Even though antimutagenic activity showed dose-dependent, it remained constant at inhibition rate ranging 60~90% when the concentration was abov 3mg/plate in the S. typhimurium reversion assay and 0.2~0.6 mg/assay in the SOS chromotest. The antimutagenic activity of the methanol extracts was stable at various pH (2, 7 and 10), temperatures (60, 80 and 10$0^{\circ}C$)and heation times (2, 4, 6, 8, 10 min at 10$0^{\circ}C$).

• Preventive Nutrition and Food Science
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• v.4 no.1
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• pp.33-37
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• 1999

The antimutagenic effects of buchu kimchi and Chinese cabbage kimchi and theri cytotoxic effects against human cancer cell line were investigated in the Salmonella typhimurium system and MTT assay, respectively. Leek and Chinese cabbage were aslo evaluated in the same system. Buchu kimchi was fermented at 15 $^{\circ}C$ for 4 days . Buchu kimchi samples showed somewhat higher antimutagenic effects against aflatoxin B1(AFB1) than CHinese cabbage kimchi in Salmonella typhimurium TA100 strain. There was no difference onthe antimutagenic activity according to the length of fermentation . Leek exerted stronger antimutagenicity against AFB1 than Chinese cabbage in the Ames assay. In MTT assay, 6-day fermented buchu kimchin revealed the highest cytotoxicity against AGS human gastric adenocarcinoma cells in which 62% and 82% of the inhibition were observed wiht the addition of 100ug, 400ug/well, respectively. Buchu kimchi samples caused 60~70% inhibition on the proliferation of HT-29 at 400ug/well. Leek exhibited higher antiproliferative effect against both AGS cells and HT-29 cells than Chinese cabbage in MTT assay. From these results, it is considered that buchu kimchi has stronger antimutagenic and in vitro anticancer effects than Chinese cabbage kimchi and the high inhibition rate of buchu kimchi probably results from leek, the major ingredient of buchu kimchi .