• YAKHAK HOEJI
• /
• v.17 no.1
• /
• pp.17-20
• /
• 1973

Six novel compounds of N,N-dimethyl-N'-(6-substituted-2-benzothiazolyl) formamidines nad six novel compounds of N, N-dimethyl-N'-(substituted-phenyl)formamidines were synthesized. They were evaluated fro their bactericidal activities aginst Salmonella typhoso, Escherichia coli, Vibrio cholera, Staphyloccus aureus, Sarcina lutea and for their fungicidal activities against Saccharomyces cereviseae, Candida albicans. It was found that these compounds were considerably more active than phenol, especially against Vibrio cholera, and N, N-dimethy-N'-(4-methyl-phenyl_formamkidine, N, N-dimethyl-N'-(2-methyl-4-bromo-phenyl)formanidine showed most potent bactericidal activities.

• Korean Journal of Veterinary Research
• /
• v.10 no.2
• /
• pp.53-57
• /
• 1970

Hog cholera (HC) virus detection from the artificially infected pigs was made using fluoreescent antibody technique (FAT) and END method. It was observed that the swine origin virulent was detected in most of the organs tested at the early stage of the infection, while the tissue culture attenuated virus was detected only in blood (transitionally), lung, and tonsil.

• The Korean Nurse
• /
• v.3 no.2 s.10
• /
• pp.51-57
• /
• 1964

• The Korean Nurse
• /
• s.8
• /
• pp.53-58
• /
• 1963

• KOREAN POULTRY JOURNAL
• /
• v.4 no.11 s.37
• /
• pp.66-68
• /
• 1972

• Parasites, Hosts and Diseases
• /
• v.56 no.1
• /
• pp.1-9
• /
• 2018

Giardia lamblia, an anaerobic, amitochondriate protozoan parasite causes parasitic infection giardiasis in children and young adults. It produces pyruvate, a major metabolic product for its fermentative metabolism. The current study was undertaken to explore the effects of pyruvate as a physiological antioxidant during oxidative stress in Giardia by cysteine-ascorbate deprivation and further investigation upon the hypothesis that oxidative stress due to metabolism was the reason behind the cytotoxicity. We have estimated intracellular reactive oxygen species generation due to cysteine-ascorbate deprivation in Giardia. In the present study, we have examined the effects of extracellular addition of pyruvate, during oxidative stress generated from cysteine-ascorbate deprivation in culture media on DNA damage in Giardia. The intracellular pyruvate concentrations at several time points were measured in the trophozoites during stress. Trophozoites viability under cysteine-ascorbate deprived (CAD) medium in presence and absence of extracellular pyruvate has also been measured. The exogenous addition of a physiologically relevant concentration of pyruvate to trophozoites suspension was shown to attenuate the rate of ROS generation. We have demonstrated that Giardia protects itself from destructive consequences of ROS by maintaining the intracellular pyruvate concentration. Pyruvate recovers Giardia trophozoites from oxidative stress by decreasing the number of DNA breaks that might favor DNA repair.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.3
• /
• pp.627-636
• /
• 2016

The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

• Korean Journal of Veterinary Research
• /
• v.46 no.2
• /
• pp.127-133
• /
• 2006

Pasteurella multocida is a terrible veterinary pathogen that causes widespread infections in husbandry. To induce homologous and/or heterologous immunity against the infections, outer membrane protein Hs (OmpH) in the envelope of different strains of P. multocida are thought to be attractive vaccine candidates. Previously we cloned and characterized a gene for OmpH from pathogenic P. multocida (A : 3) (In Press, Korean J. Microbiol. Biotechnol. 2005, 33, December). The gene is composed of 1,047 nucleotides (nt) coding 348 amino acids (aa) with signal peptide of 20 aa. The truncated ompH, a gene without nt coding for the signal peptide, was generated using pRSET A to name "pRSET A/OmpH-F2". This truncated ompH was well expressed in Escherichia coli BL21 (DE3). Truncated OmpH was purified for induction of immunity against live pathogen of fowl cholera (P. multocida A : 3) in mice. Some $50{\mu}g$ of the purified polypeptide was intraperitoneally injected into mice two times with 10 day interval. Lethal dose ($25{\mu}l$) of live P. multocida A : 3 was determined by directly injecting the pathogen into wild mice (n = 25). To demonstrate the vaccine candidate of the truncated OmpH, the live pathogen ($25{\mu}l$) was challenged with the OmpH-immunized mouse group as well as positive & negative controls (n = 80). The results show that the truncated OmpH can be used for an effective vaccine production to prevent fowl cholera caused by pathogenic P. multocida (A : 3).

• Genomics & Informatics
• /
• v.13 no.2
• /
• pp.53-59
• /
• 2015

In developing countries threat of cholera is a significant health concern whenever water purification and sewage disposal systems are inadequate. Vibrio cholerae is one of the responsible bacteria involved in cholera disease. The complete genome sequence of V. cholerae deciphers the presence of various genes and hypothetical proteins whose function are not yet understood. Hence analyzing and annotating the structure and function of hypothetical proteins is important for understanding the V. cholerae. V. cholerae O139 is the most common and pathogenic bacterial strain among various V. cholerae strains. In this study sequence of six hypothetical proteins of V. cholerae O139 has been annotated from NCBI. Various computational tools and databases have been used to determine domain family, protein-protein interaction, solubility of protein, ligand binding sites etc. The three dimensional structure of two proteins were modeled and their ligand binding sites were identified. We have found domains and families of only one protein. The analysis revealed that these proteins might have antibiotic resistance activity, DNA breaking-rejoining activity, integrase enzyme activity, restriction endonuclease, etc. Structural prediction of these proteins and detection of binding sites from this study would indicate a potential target aiding docking studies for therapeutic designing against cholera.

• BMB Reports
• /
• v.38 no.6
• /
• pp.717-724
• /
• 2005

The nontoxic B subunit of cholera toxin (CTB) can significantly increase the ability of proteins to induce immunological tolerance after oral administration, when it was conjugated to various proteins. Recombinant CTB offers great potential for treatment of autoimmune disease. Here we firstly investigated the feasibility of silkworm baculovirus expression vector system for the cost-effective production of CTB under the control of a strong polyhedrin promoter. Higher expression was achieved via introducing the partial non-coding and coding sequences (ATAAAT and ATGCCGAAT) of polyhedrin to the 5' end of the native CTB gene, with the maximal accumulation being approximately 54.4 mg/L of hemolymph. The silkworm bioreactor produced this protein vaccine as the glycoslated pentameric form, which retained the GM1-ganglioside binding affinity and the native antigenicity of CTB. Further studies revealed that mixing with silkworm-derived CTB increases the tolerogenic potential of insulin. In the nonconjugated form, an insulin : CTB ratio of 100 : 1 was optimal for the prominent reduction in pancreatic islet inflammation. The data presented here demonstrate that the silkworm bioreactor is an ideal production and delivery system for an oral protein vaccine designed to develop immunological tolerance against autoimmune diabetes and CTB functions as an effective mucosal adjuvant for oral tolerance induction.