• Journal of Naturopathy
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• v.7 no.1
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• pp.20-25
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• 2018

The purpose of this study was investigated to observe the relatively low amino acid mutations in six different strains of ATCC or KCTC Salmonella strains (four species and two isolates). The mutations in the strains were to be detected and compared with the genes csgA and csgB corresponding to the Thin aggregative fimbriae. Amino acid mutations in the strains were observed from Ser20→ Gly(AGT→GGT) in the csgA gene, Asp25→Ala(GAT→GCT) and Lys66→Thr(AAA→ACA) in the csgB gene. Among the six strains, the two most common amino acid variations were observed in S. typhimurium - TH strains. On the other hand, no mutation of nucleotide sequence was observed in the strains of S. typhimurium ATCC 13311 and S. typhimurium KCTC 1925. In conclusion the genes csgA and csgB in the strains may be useful for the evaluation and detection of amino acid mutation.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.335-341
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• 2011

In this study, 22 clinical isolates of Enterobacteriaceae including Citrobacterfreundii (6 strains), Enterobacter cloacae (5 strains), Enterobacter aerogenes (3 strains), Serratia marcescens (7 strains) and Pantoea spp. (1 strain) were investigated for the biofilm forming ability and biosynthesis of curli and cellulose. Biofilm forming ability was the highest among the isolates of E. cloacae and the lowest among the isolates of E. aerogenes. The expression of the biofilm-forming extracellular matrix components, cellulose and curli fimbriae, was examined by Congo-red (CR) staining and calcofluor staining methods. PCR screening for the presence of curli gene (csgA) revealed that 4 strains of E. cloacae and 1 strain of C. freundii carried the csgA, showing a good correlation between the phenotypic detection of curli fimbriae by CR staining method and the genotypic detection of curli gene by PCR in E. cloacae.

• Journal of Life Science
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• v.13 no.2
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• pp.184-190
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• 2003

Myxococcus xanthus is a Gram negative, rod-shaped, soil bacterium that displays a social behaviors, and multicellular development upon nutrient deprivation. The csgA gene encoding a cell surface protein is essential for developmental behaviors including rippling, aggregation, fruiting body formation and sporulation. csgA mutants show normal vegetative growth, but lack all these developmental phenotypes. Expression of the CsgA (C-signal) specific genes are eliminated or dramatically reduced in csgA mutants. In order to identify components of C-signal transduction pathway, second site mutations were introduced into csgA mutants and were identified which can fully or partially restore development of csgA mutants (Rhie, H. G. et. al. 1989. J. Bacteriol. 171, 3268-3276). One of such csgA suppressor mutations, socD500 restores only sporulation to csgA mutants at 15$^{\circ}C$. The socD500 mutaion however eliminates the three basic developmental requirements, starvation, high cell density and a solid surface. Only sporulation, not accompanied with fruiting body formation is induced simply by shifting the temperature of vegetatively growing cells from $32^{\circ}C$ to $15^{\circ}C$. Spores induced by socD500 mutation is not as thick as that of wild-type fruiting body. In socD500 genetic background, two of ten C-signal dependent genes, $\Omega$DK4506 and $\Omega$DK4406 are more highly expressed in growing cells at $15^{\circ}C$. These results indicate that the socD500 mutation may be partly involved in the regulation of expression of two C-signal dependent genes and genes for sporulation in this transduction pathway.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.50-50
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• 2002

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2363-2367
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• 2012

Objective: To investigate the association between the connexin 37 C1019T polymorphism and Helicobacter pylori infection in patients with gastric cancer. Methods: 388 patients with gastric cancer (GC), 204 with chronic superficial gastritis (CSG) were studied. H. pylori was detected by gastric mucosal biopsies biopsy dyeing method. Connexin 37 gene polymorphism 1019 site genotypes were determined by gene sequencing technology. Genotypes and alleles frequencies were compared. Results: (1) Connexin37 gene 1019 site distribution frequency (CC type, TC type, TT type) in the CSG group was 18.1%, 45.1% and 36.8%; in the stomach cancer group it was 35.1%, 45.9% and 19.%, conforming to the Hardy-Weinberg euilibrium. (2) In comparison with CSG group, the frequency of Connexin37 C allele was higher in the gastric cancer group (58.0% vs 40.7%, OR = 2.01, 95%CI = 1.58-2.57, P < 0.01). The prevalence of gastric cancer risk was significantly increased in the carriers of C allele (CC+TC) than in TT homozygote (OR = 2.47, 5%CI = 1.68- 3.610. (3) Gastric cancer patients complicated with Hp infection 211 cases, gastric cancer group of the male patients with HP positive patients with 187 cases, 40 cases of female patients with negative patients, 24 cases were HP positive, negative in 137 cases, control group male patients, 28 cases were Hp positive, negative in 95 patients, female patients with Hp positive 6 cases, 75 cases were negative. On hierarchical analysis, the male group OR value was 15.9 (95%CI to 9.22-27.3), and the female OR was 2.19 (95%CI 0.88-5.59), indicating a greater contribution in males (P <0.01). After elimination of gender effects, positive HP and gastric cancer were closely related (OR 8.82, 95% CI: 5.45-14.3). (4) The distribution frequency of C allele in patients with Hp infection was much higher than that in Hp negative cases in the GC group (64.5% vs 47.0%, OR = 2.05, 95%CI = 1.54-2.74, P < 0.01). Compared with TT homozygotes, (CC+TC) genotype prevalence of gastric cancer risk increased significantly (OR = 2.96, 5%CI = 1.76-2.99 ). Conclusion: The T allele in the connexin37 gene might not only be associated with gastric cancer but also with H. pylori infection.

• KSBB Journal
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• v.24 no.1
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• pp.25-29
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• 2009

Ceramide is important not only for the maintenance of the barrier function of the skin but also for the water-binding capacity of the stratum corneum. Though the effectiveness of ceramide is not understood fully, ceramide has become a widely used ingredient in cosmetic and pharmaceutical industries. However, ceramide production from Saccharomyces cerevisiae has not been widely studied and the quantity are very low. Gene deletion in the cell is used frequently to investigate the function of gene and verification research of drug target. Specially, deletion mutant library is useful for a large amount functional analysis of gene. In this study, deletion mutants of genes on the metabolic pathway of ceramide synthesis in S. cerevisiae were grown in a batch culture and the cellular content of ceramide was measured. The ceramide content was highest in ${\triangle}$ydc1 mutant and 6 mg ceramide/g cell was obtained.