• Fisheries and Aquatic Sciences
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• v.26 no.9
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• pp.558-568
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• 2023

Vibrio vulnificus is an aquatic bacterium causing septicemia and wound infection in humans. To understand this pathogen at the genomic level, it was performed whole genome sequencing of a cefoxitin-resistant strain, V. vulnificus 1908-10 possessing virulence-related genes (vvhA, viuB, and vcgC) isolated from Gadeok island coastal seawater in South Korea. The genome of V. vulnificus 1908-10 consisted of two circular contigs and no plasmid. The total genome size was estimated to be 5,018,425 bp with a guanine-cytosine (GC) content of 46.9%. We found 119 tRNA and 34 rRNA genes respectively in the genome, along with 4,352 predicted protein sequences. Virulence factor (VF) analysis further revealed that V. vulnificus 1908-10 possess various virulence genes in classes of adherence, antiphagocytosis, chemotaxis and motility, iron uptake, quorum sensing, secretion system, and toxin. In the comparison of the presence/absence of virulence genes, V. vulnificus 1908-10 had fur, hlyU, luxS, ompU, pilA, pilF, rtxA, rtxC, and vvhA. Of the 30 V. vulnificus comparative strains, 80% of the C-genotype strains have all of these genes, whereas 40% of the E-genotype strains have all of them. In particular, pilA were identified in 80% of the C-type strains and 40% of the E-type strains, showing more difference than other genes. Therefore, V. vulnificus 1908-10 had similar VF characteristics to those of type C strains. Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin of V. vulnificus 1908-10 contained 8 A-type repeats (GXXGXXXXXG), 25 B.1-type repeats (TXVGXGXX), 18 B2-type repeats (GGXGXDXXX), and 7 C-type repeats (GGXGXDXXX). The National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) showed that the RtxA protein of V. vulnificus 1908-10 had the effector domain in the order of cross-liking domain (ACD)-C58_PaToxP-like domain- α/β hydrolase-C58_PaToxP-like domain.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.254-284
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• 2015

Objectives: There is a requirement to select target materials for mutagenicity(Genotoxicity) testing, so we determined to set the test priorities of them by searching the related database. Methods and Results: We searched a number of databases to find information on mutagenicity tests with chemicals under the Occupational Safety and Health Act(OSH Act), such as KOSHANET, National Toxicology Program(NTP), European Chemicals Agency(ECHA), US National Library of Medicine(NLM), and Genetic Toxicology Data Bank(GENE-TOX), as well as ChemIDplus webpage, and presented the information. Also we anticipated their hazards with ACToR sites to confirm the 58 mutagenicity(Genotoxicity) tests we will perform. Conclusions: We presented target materials for mutagenicity testing with specific GLP tests consisting of reverse mutation(Ames), chromosomal aberration and micronucleus test.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.66.1-66
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• 2003

The aim of this study was to characterize the interactions of rice and Burkholderia glumae, a causal agent of bacterial grain rot of rice, at molecular levels using whole genomic sequences and to identify genes important for pathogenicity and symptom development. To do these, we sequenced whole genome of the bacterium and constructed cosmid clone profiles. We generated pools of mutants using various transposons and determined mutation sites by sequencing rescued plasmids. We focused on studying toxoflavin biosynthetic genes, quorum sensing regulation, and Hrp type III protein secretion systems. We found that two possible operons consisting of five genes are involved in toxoflavin biosynthesis and their expression is regulated by quorum sensing and LysR-type regulator, ToxR. We have isolated the nn PAI of B. glumae and characterized by mutational analyses. The hrp cluster resembled most the putative Type III secretion systems of B. pseudomallei, which is the causative agent of melioidosis, a serious disease of man and animals. The Hrp PAI core region showed high similarity to that of Ralstonia solanacearum and Xanthomonas campestris, however some aspects were dissimilar.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.58-64
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• 2003

A mechanical press joining was investigated in ender for joining A1-5052 sheets for automobile body weight reduction. Static tensile and fatigue tests were conducted using tensile-shear specimens for evaluation of fatigue strength of the joint. During Tox joining process for A1-5052 plates, using the current sheet thickness and punch diameter, the optimal applied punching force was found to be 32 kN under the current joining condition. For the static tensile-shear experiment results, the fracture mode is classified into interface fracture mode, in which the neck area fractured due to influence of neck thickness, and pull-out fracture mode due to influence of plastic deformation of the joining area. And, during fatigue tests for the A1-5052 tensile shear specimens, interface failure mode occurred in the region of low cycle. The fatigue endurance limit approached to 6 percents of the maximum applied load, considering fatigue lifetime of $2.5\times10^6$ cycles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.596-604
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• 2019

Vibrio parahaemolyticus causes food poisoning, mainly via marine fisheries products. We investigated the virulence factors and drug resistance of V. parahaemolyticus isolated from fisheries products purchased from the Yeosu Fisheries Market. The isolates were identified using a variety of biochemical tests and the detection of toxR and hns gene. The presence of the virulence factor-encoding genes tdh and trh in the isolates was also investigated by PCR. The resistance of the isolates to 13 antibacterial agents was tested using the disc-diffusion method and carriage of β-lactamase genes and class 1 integrons by ampicillin-resistant isolates was investigated by PCR. Four of seventeen isolates identified as V. parahaemolyticus by biochemical tests produced a species-specific PCR band. Those isolates showed >98% 16S rRNA gene sequence homology with V. parahaemolyticus and only one isolate harbored the tdh gene. All of the V. parahaemolyticus isolates were resistant to ampicillin and amoxicillin; moreover, VPA0477, a class A β-lactamase gene, and class 1 integrons were detected. Therefore, V. parahaemolyticus from fisheries products represents a low risk to human health. Also, V. parahaemolyticus is likely to develop multidrug resistance because it has class 1 integrons.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.29-32
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• 2002

The mechanical joining process of a sheet metal pair has been developed in order to replace the resistance spot welding process in case that joining of mechanically unweldable materials and coated sheet metals with different thickness are needed. Form-joining or clinching, a kind of mechanical joining process, is defined as joining process of a sheet metal pair by geometric constraint imposed by plastic deformation of workpieces without any additive part. It has been reported that the joining strength by commercial form-joining apparatus is 50∼70 percent of that by resistance spot welding. Therefore, a two-step form-joining process with a secondary punch is proposed. The device is designed to improve the joining strength by increasing the geometric constraint of the deformed shape by combining a primary punch, a secondary punch and a female die. In order to verify the improved joining strength by the designed process, the tensile-shear strength, the peel-tension strength and the asymmetric peel-tension strength are compared with those by the TOX process and resistance spot welding.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.592-597
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• 2008

Current water quality standard (WQS) in Korea is based on the protection of human health, not considering the protection of aquatic organisms. Most of chemicals can be toxic to ecological biota as well as human. Health of aquatic biota is closely related to the human health via food chain, therefore ecological risk based-WQS needs to be developed to protect the aquatic ecosystem. In this study, we selected the 31 chemicals in the Project entitled 'Development of integrated methodology for evaluation of water environment'. The methodology for calculating water quality criteria was derived from the Australian and New Zealand processes for deriving guideline trigger value for aquatic ecosystem. The available ecotoxicity data were collected from US EPA's ECOTOXicology Database (ECOTOX), TOX-2000 Database, European Chemicals Bureau (ECB)'s International Uniform Chemical Information Database (IUCLID) and Environmental Protection Agency (US EPA)'s report 'Ambient Water Quality Criteria (AWQC)'. The aquatic toxicity data for the Korean species were selected for risk assessment to reflect the Korean water environment. The monitoring values were calculated from the water quality monitoring data four main Korean rivers. We suggested the order of priorities of chemicals based on ecological risk assessment. We expect that these results can be useful information for establishing the WQS for the protection of aquatic ecosystem.

• Journal of Microbiology
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• v.45 no.4
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• pp.364-366
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• 2007

The immunological role of the Pasteurella multocida toxin (PMT) in mice was examined using a PMT mutant strain. After a nasal inoculation, the mutant strain failed to induce interstitial pneumonia. Moreover, PMT had no significant effect on the populations of CD4+, CD8+, CD3+, and CD19+ immunocytes in blood or on the populations of CD4+ and CD8+ splenocytes (P<0.01). However, there was a significant increase in the total number of cells in the BAL samples obtained from the wild-type P. multocida-inoculated mice. On the other hand, the level of IL-l expression decreased when the macrophages from the bronchio-alveolar lavage were stimulated with PMT. Overall, PMT appears to play some role (stimulating and/or inhibiting) in the immunological responses but further studies will be required to confirm this.

• KSBB Journal
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• v.26 no.5
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• pp.412-416
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• 2011

The conventional monitoring system for water pollution measurement is quite simple and independent and it has a lot of draw backs such as cost, installation, etc. So, in this paper, we have measured the water pollution system through a bacterial species, photobacterium phosphoreum. A novel integrated monitoring system technology has been developed which could easily dictate and analyze the major water pollutants and its surrounding environment in an accurate way. The system constitutes of bionic technology, information technology and environmental engineering technology. As a result, integrated monitoring system can observe the water pollution and various water environment of the whole country. Also, through the sensors of USN, Zigbee, RFID and middle ware, which can provide service and construct service platform, a properly standardized plan with remarkable service platform has been established through this investigation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.4
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• pp.406-415
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• 2018

Objective: The purpose of this study was to investigate the hazards of cosmetic ingredients in Korea. Methods: An Excel database of cosmetic ingredients was developed on a website(Korea Cosmetic Ingredient Dictionary) and used for a hazard assessment based on Tox-free, a database containing toxic information such as on carcinogens, mutagens or reproductive toxicants(CMRs) and endocrine disrupting chemicals(EDCs), as well as other regulated chemicals in Korea. Results: A total of 16,605 chemicals were registered with the cosmetic ingredient dictionary and 308 of them were identified as either CMRs or EDCs. CMRs included formaldehyde and nickel gluconate, and EDCs included parabens, benzophenon, styrene, and toluene. Reproductive toxicants such as xylene, zinc chloride, toluene, and formaldehyde were regulated by the Occupational Safety and Health Act and the Act on the Registration and Evaluation, etc. of Chemical Substances(the Chemical Control Act). Conclusions: Regulations on cosmetics components should be strengthened, and the right to know about cosmetics containing hazardous chemicals should be guaranteed.