• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.525-528
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• 1999

Mutagenic activities of extracts from the filtrate of the cultured broth (PI-I), mycelia (pI-II), and the fruiting bodies (PI-III) of Phellinus igniarius were examined by Ames/Salmonella tests. No mutagenic activity was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PI-I, PI-II, and PI-III showed inhibitory effects on the mutagenic activities by the directly-acting mutagens, 4-nitro-ο-phenylenediamine(NPD) and sodium azide ($NaN_3$), and also by the indirectly-acting mutagens, 2-aminofluorene (2-AF) and benzo[a]pyrene (B[a]P). These results suggest that P. igniarius possesses some antimutagenic activity and may contain some chemopreventive agents.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.122-125
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• 2010

The essential oil fraction was extracted from the aerial parts of the plant by steam distillation method and its composition was analyzed by GC-MS (gas chromatography-mass spectrometry) which led to the identification of 43 compounds. Dehydroelsholtzia ketone (56.81%) and elsholtzia ketone (30.05%) were identified as the predominant components of this oil. The antibacterial activities of the essential oil fraction were assessed by micro-dilution tests against antibioticsusceptible and -resistant strains of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and S. typhimurium. The oil inhibited most of the tested strains significantly resulting MICs (minimum inhibiting concentrations) between 2 mg/ml and >16 mg/ml. In most cases of this study Streptococcus pneumoniae and Staphylococcus aureus showed higher sensitivity to this oil than Salmonella strains.

• Fibers and Polymers
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• v.6 no.3
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• pp.235-243
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• 2005

A series of new metallized direct dyes based on benzidine congeners, 2,2'-dimethyl-5,5'-dipropoxybenzidine and 5,5'-dipropoxybenzidine, were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA 100. All of the dyes examined were judged to be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of dyes for mutagenicity.

• Fibers and Polymers
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• v.6 no.4
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• pp.297-305
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• 2005

A series of new direct dyes based on benzidine congeners, 2,2'-dimethyl-5,5'-dipropoxybenzidine and 5,5'-dipropoxybenzidine, were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. All of the dyes examined were judged to be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of direct dyes for mutagenicity.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.553-560
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• 2005

The stf (Salmonella typhimurium fimbriae) operon consisting of stfA(CDEFG assumes to encode putative fimbriae. The complete stf operon is existed in S. typhimurium and S. choleraesuis, whereas it is absent in S. typhi. Analyses of the amino acid residues between major subunit StfA of the Stf fimbriae and those of known other fimbriaes suggested that Stf belongs to class I type fimbriae. Through comparison of StfD chaperone with the other fimbrial chaperones, and of C-terminus in subunits of Stf fimbriae, it belongs to FGS (with a short Fl-G1 loop) subfamily. In order to investigate the expression of stf operon, we have constructed a Salmonella strain containing a chromosomal stfA::lacZYA transcriptional fusion, resulting in S. typhimurium $_X8532$. The strain $_X8532$ lacked the expression of \beta-galactosidase$ under normal culture conditions. However, with longer incubation time of the S. typhimurium $_X8532$, we have isolated 21 individual strains exhibiting $Lac^+$ phenotype. $Lac^+$ phenotype was appeared as approximately 0.03 frequency per generation. All isolates expressed lacZ constitutively in the various environmental conditions. Various global regulatory proteins including RpoS, OmpR, and CpxR were not involved in the regulation of the stf operon. A S. typhimurium $_X8661$ mutant lacking stfAC function attenuated 6.7 folds more than that of wild type $_X3761$ in the mouse virulence test, suggesting in the somehow involved in the Salmonella pathogenesis.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.90.1-90.1
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• 2007

See Full Text

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.91.1-91.1
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• 2007

See Full Text

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.505-514
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• 2000

This study was conducted to investigate the isolation prequency, serotypes, and related epidemiological properties of 341 Salmonella spp from domestic poultry and environmental samples during the period 1993-1995. A total of 1,918 samples was collected during the three years period in nationwide. Most of Salmonella spp were isolated from the intestinal contents of poultry, especially cecal(46.0%) and rectal(35.8%) contents. Among the tested samples, rat(28.5 %) was the most predominant Salmonella reservoirs and followed by duck(24.8%), broiler(18.8%), layer(14.8%) and feed(7.1%), in order. More than twelve Salmonella serovars were identified among the 341 Salmonella isolates. The most prevalent serotypes isolated from non-human sources were S enteritidis (22.3%) and S pullorum (21.9%), S muenchen (13.9%), S typhimurium (12.6%), S gallinarum, S meleagridis, S heidelberg, and S senftenberg were followed, in order. In layer chickens, S pullorum (26.0%) was the most predominant serotype but S muenchen (33.0%) was in broiler chickens, S enteritidis (28.4%) was in ducks, and S typhimurium (60.0%) was in rats, respectively. As a results, S enteritidis was identified as the most prevalent serotype in non-human Salmonella isolates in Korea during the period 1993-1995. A preliminary study on the phage typing of 19 S enteritidis selected from the nationwide scale was shown that S enteritidis phage type(PT) 4 was the most predominant PT, and SEPT 1, SEPT 6a, SEPT 7 and SEPT 7a variant were also found in the same period.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.156-162
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• 2012

A mannitol dehydrogenase (StMDH) gene was cloned from Salmonella typhimurium LT2 (KCTC 2421) and overexpressed in Escherichia coli. It has a 1,467 bp open reading frame encoding 488 amino acids with deduced molecular mass of 54 kDa, which shares approximately 36% of amino acid identity with known long-chain dehydrogenase/reductatse (LDR) family enzymes. The recombinant StMDH showed the highest activity at $30^{\circ}C$, and pH 5.0 and 10.0 for D-fructose reduction and D-mannitol oxidation, respectively. On the contrary, it has no activity on glucose, galactose, xylose, and arabinose. StMDH can catalyze the oxidative/reductive reactions between D-fructose and D-mannitol only in the presence of $NAD^+$/NADH as coenzymes. These results indicate that StMDH is a typical $NAD^+$/NADH-dependent mannitol dehydrogenase (E.C. 1.1.1.67).

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1606-1610
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• 2005

The effects of Whangkumtang extract and Scutellariae radix extract on the microbial growth were investigated. The antimicrobial activities and cell growth inhibiting effects were investigated to selected strains with different concentrations of Whangkmtang and Scutellariae radix extracts. Whangkmtang and Scutellariae radix extracts showed the antimicrobial activities on Staphylococcus aureus, Bacillus cereus, Shigella sonnei, Shigella flexneri, Salmonella Typhimurium, Salmonella Enteritidis, Vibrio parahaemolyticus, Escherichia coli O111 and Escherichia coli O126. Whangkumtang and Scutellariae radix extracts did not show the antimicrobial activity on Listeriamonocytogenes. Scutellariae radix extract showed the antimicrobial activity on Escherichia coli O157 but Whangkumtang extract did not, Minimum inhibitory concentrations (MIC) of Whangkumtang extract for each strain appeared to 40 mg/mL on Staphylococcus aureus and Bacillus cerus, 100 mg/mL on Shigella Flexneri and Salmonella enteritidis. The MICs of Sutellariae radix extract appeared to 10 mg/mL on Bacillus cereus, 20 mg/UL on Staphylococn aureus, Shigellanexneri and Salmonella Enteritidis. Scutellariae radix extract showed the higher antimicrobial activity than Whangkumtang extract. The cell growth inhibitions by Whangkumtang and Scutellariae radix extracts were observed from Staphylococcus aureus and Bacillus cereus, repectively, during 48-hr incubation period.