• The Journal of the Korean Society for Microbiology
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• v.19 no.1
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• pp.73-77
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• 1984

Vibrio vulnificus is an organism capable of causing septicemia and wound infection in compromised patients. The source of infection is known to be raw oysters and others. The prevalence of the organism in Korean sea water and shellfish is not known. The authors surveyed shellfish and other specimens obtained mainly from a market in Seoul and from ones in Inchon. Five cultures of V. vulnificus were isolated from oyster and clam samples. Two isolates had typical characteristics of the strains isolated from patients, i.e., definite hemolysis and typical biochemical reactions. However, other 2 isolates were sucrose positive, although the identity were confirmed by Center for Disease Control. We do not know wether such strains are pathogenic or not. For the isolation of V. vulnificus from environmental samples, TCBS agar and VV agar were not very selective or differential. We isolated our strains with the use of OF-lactose agar and SPS agar. However OF-lactose agar did not support good growth of V. vulnificus, while SPS agar did not suppress other vibrios.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.788-792
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• 2009

Gamma $({\gamma})-irradiation$ can be used to control pathogens such as Vibrio vulnificus in seafood. The effects of irradiation on microbial cell populations (%) have been studied in order to develop detection methods for irradiated foods. The method used in this study was ethidium bromide monoazide (EMA) real-time polymerase chain reaction (PCR), using V. vulnificus specific primer, EMA, and $SYBR^{(R)}$ Green to discriminate between ${\gamma}-irradiated$ and non-irradiated cells. Confocal microscope examination showed that ${\gamma}-irradiation$ damaged portions of the cell membrane, allowing EMA to penetrate cells of irradidated V. vulnificus. ${\gamma}-Irradiation$ at 1.08 KGy resulted in log reduction ($-1.15{\pm}0.13$ log reduction) in genomic targets derived from EMA real-time PCR. The combination cold/heat shock resulted in the highest ($-1.74{\pm}0.1$ log reduction) discrimination of dead irradiated V. vulnificus by EMA real-time PCR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.625-630
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• 2019

The pathogenic Vibrio genus contains halophilic bacteria that are distributed in marine and freshwater environments. Vibrio cholerae, Vibrio vulnificus, and Vibrio parahaemolyticus are potent human pathogens and leading causes of septicemia, wound infection, and seafood-borne gastroenteritis. The aim of this study was to investigate the presence of pathogenic Vibrio species in seawater off the west coast of Korea. Sixty-four seawater samples were obtained from different sites in Gomso Bay and Byeonsan from April 2018 to November 2018. Pathogenic Vibrio species were detected using a combination of most probable number (MPN)-polymerase chain reaction methods. V. cholerae, V. vulnificus, and V. parahaemolyticus were found in 0.0%, 20.3%, and 65.6% of seawater samples, respectively. Quantitative results revealed 3.6-23 MPN/100 mL of V. vulnificus, and 3.6-930 MPN/100 mL of V. parahaemolyticus in the samples. Overall, these results provide new insight into the necessity for seawater sanitation in Gomso Bay and Byunsan; they also provide evidence that will help reduce outbreaks of seafood-borne illness caused by pathogenic Vibrio species.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.220-220
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• 2020

Astaxanthin, a natural carotenoid component of shrimp, has been used as a food additive for the treatment of various diseases, but a functional role of Astaxanthin Nanosphere (AN) in the regulation of intestinal mucin (Muc) 2 production during bacterial infection has not described yet. In this study, we have investigated the effect of AN prepared from astaxanthin during Muc2 repression elicited by the Gram-negative bacterium V. vulnificus in human gastrointestinal epithelial (HT-29) cells. AN significantly inhibited the level of ROS production and PKC activation in recombinant protein (r) VvpE-stimulated HT-29 cells. Moreover, AN inhibited the PKC-mediated phosphorylation of extracellular signal-regulated kinase and nuclear factor-kappa B responsible for region-specific hypermethylation in the Muc2 promoter in rVvpE-treated HT-29 cells. In the mouse models of V. vulnificus infection, treatment with AN maintained the level of Muc2 expression in the intestine. On the basis of these results, we suggest that AN blocks the hypermethylation of the Muc2 promoter to restore the level of Muc2 production in HT-29 cells infected with V. vulnificus.

• Journal of Life Science
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• v.12 no.6
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• pp.669-675
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• 2002

Introduction of sliced raw fish meat(SRFM) to fast food business has been considered seriously. However bacteria causing food poisoning should be controlled. Organic acids such as vinegar and lactic acid used in the sauce for SRFM were evaluated for their antibacterial activities. At low concentration levels of vinegar and lactic acid exerted strong antibacterial activities toward Vibriu sp.. In contrast, in case of Salmonella typhimurium and Escherichia coli O157:H7 low anitbacterial activities were observed even at relatively high concentrations. Minimum inhibitory concentrations(MIC) of vinegar for V. vulnificus, V. cholerae non-O1, V. parahaemolyticus, V. mimicus, S. typhimurium and E. coli O157:H7 were 16, 18, 16, 12, 26, and $20{\mu}\ell /m\ell, respertively. MIC of lactic acid for V. vilnificus, V. cholerae non-O1, V. parahaemolyticus, V. mimicus, S. typhimurium and E. coli O157:H7 were 20, 25, 25, 25, 40, and $35{\mu}\ell /m\ell, respectively. In case of vinegar bactericidal concentration upon 10 second contact for V. vulnificus, V. cholerae non-O1, V. parahaenolyticus, V. mimicus and E. coli O157:H7 were 8, 14, 10, 4, and 48%, respectively; however, even at 50% colony of S. typhimurium was observed. In case of lactic acid any colony was observed for V. vulnificus, V. cholerae non-O1, V. parahaemolyticus, V. mimicus, S. typhimurium and E. coli O157:H7 at the concentration of 2, 3, 4, 3, 14, and 17%, respectively. Vinegar and lactic acid of low concentration inhibited the growth of Vibrio sp., food poisoning pathogen in SRFM; in contrast, at high concentration these organic acids inhibited Salmonella sp. and Escherichia sp., food poisoning pathogen in other than SRFM.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.6-12
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• 2020

Prevalence of toxin genes and profiles of antibiotic resistance in Vibrio vulnificus were investigated for prevention of Vibrio sepsis and selection of effective antibiotics. A total of 23 V. vulnificus strains were isolated from Vibrio sepsis patients, fish, and water samples collected from fish tanks in restaurants in Jeonnam province during 2015-2017 period. Prevalence of toxin genes including, RtxA, viuB and vvhA were assessed and susceptibilities to 15 different antibiotics were determined. As a result of the toxin gene profile, the RtxA toxin gene was detected in 19 (82.6%) out of 23 strains, and vvhA and viuB toxin genes were positive in all strains. These results showed that V. vulnificus tested in this study possessed at least one more toxin gene, and the toxin gene detection rate was higher than in previous reports. Therefore, there is always a risk of Vibrio sepsis through eating fish or having contact with aquarium water at seafood restaurants. Especially, it was deemed necessary to provide preventive education about Vibrio sepsis for workers in such restaurants. The results of antibiotic susceptibility tests presented 94.4% resistance to cepoxitin antibiotics but all strains showed susceptibility to 14 kinds of antibiotics including chloramphenicol and tetracycline. The currents antibiotic therapy using chloramphenicol and teteracycline against Vibrio sepsis was judged to be useful.

• Journal of Microbiology
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• v.44 no.5
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• pp.537-547
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• 2006

This study was designed to determine whether or not Vibrio vulnificus metalloprotease VvpE can promote iron uptake via the proteolytic cleavage of human hemoglobin. We found that V. vulnificus utilized hemoglobin as an iron source more efficiently via the vulnibactin-mediated iron-uptake system than via the HupA-mediated iron-uptake system and, of the proteases produced by V. vulnificus, VvpE was found to be the only protease capable of destroying hemoglobin. However, VvpE expression, on both the transcriptional and protein levels, was suppressed in iron-limited media. However, vvpE transcription, but not extracellular VvpE production, was reactivated by the addition of hemoglobin or inorganic iron into iron-limited media. Moreover, vvpE transcription began only in the late growth phase when V. vulnificus had already consumed most of the iron for growth. In addition, neither vvpE mutation nor in trans vvpE complementation affected the ability of V. vulnificus to acquire iron or to grow in iron-limited media or in cirrhotic ascites containing hemoglobin. Hemoglobin added into iron-limited media was not destroyed, but gradually formed an insoluble aggregate during culture; this aggregation of hemoglobin occurred regardless of vvpE mutation or complementation. These results indicate that VvpE is not required for efficient iron uptake from hemoglobin. On the contrary, hemoglobin or iron is required for efficient vvpE transcription. In addition, a discrepancy exists between vvpE transcription and extracellular VvpE production in iron-limited media containing inorganic iron or hemoglobin, which suggests that additional unknown posttranscriptional events may be involved in the extracellular production of VvpE.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.284-289
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• 2004

A PCR assay for the rapid detection of Vibrio vulnificus strains was developed using a virulence gene for elastase found in various Vibrio species. The DNA sequences in the elastase gene facilitated the identification of a species-specific probe for pathogenic V. vulnificus strains from both clinical and environmental sources. Using an elastase gene-based PCR reaction, a species-specific 507-bp PCR product was visualized by agarose gel electrophoresis. Three different DNA extraction methods were then compared to improve the simplicity and rapidity of detection. A PCR assay using the conventional DNA extraction or boiling method was able to detect as few as 25 V. vulnificus cells, making the detection limits at least 1-log-scale lower than that for the EDT A-treated DNA extraction method. In particular, the boiling method, which does not require purification of the chromosomal DNA, was very effective in terms of simple and rapid detection. Meanwhile, the detection limit in a mixed bacterial culture that included other bacteria, such as Escherichia coli or Bacillus subtilis, was two V. vulnificus cells, which was 1-log-scale lower than that for the control. Accordingly, when coupled with a new DNA extraction method, the elastase gene-based PCR can provide a rapid, specific, and sensitive method for identifying V. vulnificus in clinical and environmental samples.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.89-93
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• 2020

Vibrio vulnificus, an opportunistic pathogen, causes septicaemia when raw shellfish and fish are eaten by patients with hepatic diseases or reduced immunity. In this study, we evaluated inhibitory effects of some natural products on V. vulnificus growth using 96-well microplate assay. We found that Phyllanthus emblica L., Rosa chinensis Jacq., Rosa rugose Thub., and Chukrasia tabularis A. Juss. significantly inhibited V. vulnificus growth in Luria-Bertani (LB) broth. Among these four extracts, the inhibition diameter of Chukrasia tabularis was 16.00 ± 0.58 mm in disc diffusion assay on V. vulnificus growth. In addition, these four natural products protected HeLa cells from V. vulnificus-induced cytotoxicity. A cocktail containing these four products showed an inhibitory effect on V. vulnificus growth in seawater and shellfish by reducing its growth by 75.7% and 97%, respectively. These results suggest that these four natural products are safe and effective natural antimicrobial candidates to prevent V. vulnificus infection.

• Proceedings of the Microbiological Society of Korea Conference
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• 2004.05a
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• pp.132-136
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• 2004

Understanding the molecular pathogenesis of the multifaceted host-pathogen interaction is critical in the development of improved treatment and prevention, as well as elucidating how certain bacteria can circumvent host defenses, multiply in the host, and cause such extensive damage. Disease caused by infection with V. vulnificus is remarkable for the invasive nature of the infection, ensuing severe tissue damage, and rapidly fulminating course. The characterization of somatic as well as secreted products of V. vulnificus has yielded a large list of putative virulence attributes, whose known functions are easily imagined to explain the pathology of disease. These putative virulence factors include a carbohydrate capsule, lipopolysaccharide, a cytolysin/hemolysin, elastolytic metalloprotease, iron sequestering systems, lipase, and pili. However, only few among the putative virulence factors has been confirmed to be essential for virulence by the use of molecular Koch's postulates. This presentation describes molecular biological characterization of the virulence factors contributing to survival as well as to toxigenesis of V. vulnificus.