• Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.3.1-3.10
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• 2018

Background: Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003-2016. Main body: V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003-2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin) or trh (tdh-related hemolysin) genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion: This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

• Genomics & Informatics
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• v.20 no.1
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• pp.11.1-11.20
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• 2022

Vibrio harveyi belongs to the Vibrio genus that causes vibriosis in marine and aquatic fish species through double-stranded DNA virus replication. In humans, around 12 Vibrio species can cause gastroenteritis (gastrointestinal illness). A large amount of virus particles can be found in the cytoplasm of infected cells, which may cause death. Despite these devastating complications, there is still no cure or vaccine for the virus. As a result, we used an immunoinformatics approach to develop a multi-epitope vaccine against most pathogenic hemolysin gene of V. harveyi. The immunodominant T- and B-cell epitopes were identified using the hemolysin protein. We developed a vaccine employing three possible epitopes: cytotoxic T-lymphocytes, helper T-lymphocytes, and linear B-lymphocyte epitopes, after thorough testing. The vaccine was developed to be antigenic, immunogenic, and non-allergenic, as well as having a better solubility. Molecular dynamics simulation revealed significant structural stiffness and binding stability. In addition, the immunological simulation generated by computer revealed that the vaccination might elicit immune reactions in the actual life after injection. Finally, using Escherichia coli K12 as a model, codon optimization yielded ideal GC content and a higher codon adaptation index value, which was then included in the cloning vector pET2+ (a). Altogether, our experiment implies that the proposed peptide vaccine might be a good option for vibriosis prophylaxis.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1352-1355
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• 2011

Forty-one Enterococcus faecalis (E. faecalis) isolates from feces of pigs and chickens in Korea were screened for the presence of virulence factors. Gelatinase activity (85.4%, 35/41) was the more commonly observed phenotype of virulence in E. faecalis, compared with hemolytic activity (12.2%, 5/41). Thirty-one of 35 (88.6%) gelatinase-positive E. faecalis isolates harbored the gelE and fsrABC genes. A gene encoding for the enterococcal surface protein (Esp) was detected in 24.4% (10/41) of the isolates. All beta-hemolysin-producing isolates harbored the esp gene.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.168-176
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• 2005

Vibrio vulnificus, one of the marine bacterial pathogens causing septicemia, was detected using molecular methods, namely, PCR and/or Southern hybridization, and real-time PCR. Extracted and purified total DNAs by using commercial kits were used as templates for PCR. Multiplex-PCR was conducted by employing three sets of primers for the genes, hemolysin (vvhA), phosphomannomutase (pmm), and metalloprotease (vvpE), for V vulnificus virulence. The presence of DMSO ($5\%$) and BSA ($0.1\%$) in PCR reaction mixture improved a detection efficiency by higher PCR band intensities. TaqMan real-time PCR was carried out by using gene segment of vvhA as a target. Detection limit of PCR/Southern hybridization without enrichments was to be around $10^2\;cells\;g^{-1}$ of sample. However, those three methods using the enrichment at $35^{\circ}C$ in APW showed high sensitivity ($2\~10\;cells\;g^{-1}$ of sediments). Highly sensitive detection of V vulnificus by real-time PCR was achieved within $5\~6$ hr, whereas the detection by PCR/Southern hybridization required about 36 hr. Thus, it was evident that real-time PCR is the most rapid and efficient method for detecting V vulnificus in tidal flat sediments.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.302-309
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• 2001

Colony blot hybridization using a VVHP DNA probe derived from the sequence of the hemolysin gene, vvhA, was specific in identifying all V. vulnificus strains, thereby, eliminating the need for any additional phenotypic identification. The colony blot hybridization procedure revealed a sensitivity and broad applicability sufficient for the direct enumeration of V. vulnificus in various natural samples, without the use of enrichment or culturing on selective medis. V. vulnificus was detected in all natural samples collected during August and May at concentrations ranging from $2.1{\times}10^1\;to\;4.0{\times}10^3$ organisms per ml. However, during November and February, when the mean temperatures of the seawater were $12^{\circ}C$ and $5^{\circ}C$, respectively, V. vulnificus was not detected in any natural samples.

• Journal of Microbiology
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• v.41 no.4
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• pp.320-326
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• 2003

In order to identify Vibrio vulnificus in the Yellow Sea near Gunsan, Korea during the early and late summers, the efficiency of the real-time quantitative TaqMan PCR was compared to the efficiency of the conventional PCR and Biolog identification system^TM. Primers and a probe were designed from the hemolysin/cytolysin gene sequence of V. vulnificus strains. The number of positive detections by real-time quantitative TaqMan PCR, conventional PCR, and the Biolog identification system from seawater were 53 (36.8%), 36 (25%), and 10 strains (6.9%), respectively, among 144 samples collected from Yellow Sea near Gunsan, Korea. Thus, the detection method of the real-time quantitative TaqMan PCR assay was more effective in terms of accuracy than that of the conventional PCR and Biolog system. Therefore, our results showed that the real-time TaqMan probe and the primer set developed in this study can be applied successfully as a rapid screening tool for the detection of V. vulnificus.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1449-1456
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• 2017

The prevalence and toxin characteristics of Bacillus thuringiensis isolated from 39 organic vegetables were investigated. B. thuringiensis was detected in 30 out of the 39 organic vegetables (76.9%) with a mean value of 2.60 log CFU/g. Twenty-five out of the 30 B. thuringiensis isolates (83.3%) showed insecticidal toxicity against Spodoptera exigua. The hblCDA, nheABC, and entFM genes were found to be the major toxin genes, but the ces gene was not detected in any of the tested B. thuringiensis isolates. The hemolysin BL enterotoxin was detected in all 30 B. thuringiensis isolates (100%). The non-hemolytic enterotoxin complex was found in 27 out of 30 B. thuringiensis isolates (90.0%). The B. thuringiensis tested in this study had similar toxin gene characteristics to B. cereus, which possessed more than one toxin gene. B. thuringiensis could have the potential risk of foodborne illness based on the toxin genes and toxin-producing ability.

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.1
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• pp.79-116
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• 2000

The KGBT has been used to weak children with anorexia, fatigue, and growth retardation. This study was carried out to prove the effects of the hematopoiesis and the immune proliferation by KGBT. Previously, C57BL/6 mice was treated with cyclophosphamide(100mg/kg) for leukopenia, and then administered KGBT (concentration is 1.37 g/kg, 504 mg/kg, and 137 mg/kg) to the treated mice. The mice was analyzed expression of thrombopoietin(TPO), stem cell factor(SCF) and interleukin-3 from bone marrow cell, interleukin-10 (IL-10), and interferon-$ {\gamma}$(INF-${\gamma}$) from splenic cell, and NOSⅡ gene from macrophage using by RT-PCR. Also proliferation of immune cell was analyzed using 3H-thymidine uptake and flow cytometery in splenic cells. The results were obtained as follows ; 1. The total number of WBC, RBC and PLT was increased in the KGBT treated group than in the control group. 2. In vitro, the proliferation of splenic cells was increased in normal, control, and KGBT treated group. And Administration of KGBT was reduced the cytotoxicity by CTX. 3. In bone marrow cell, the gene expression of immune regulatory factor that associated with hematopoiesis, such as TPO, SCF, and IL-13 was increased in the KGBT treated group than control. 4 The titer of hemagglutinin and hemolysin was increased in the KGBT treated group than control. 5. In analysis of positive leucocytes from splenic cell of BALB/c mice, the subpopulation percent of CD4+, CD8+,and CD19+ was increased in the KGBT treated group than control. The KGBT has been used to weak children with anorexia, fatigue, and growth retardation. This study was carried out to prove the effects of the hematopoiesis and the immune proliferation by KGBT. Previously, C57BL/6 mice was treated with cyclophosphamide(100mg/kg) for leukopenia, and then administered KGBT (concentration is 1.37 g/kg, 504 mg/kg, and 137 mg/kg) to the treated mice. The mice was analyzed expression of thrombopoietin(TPO), stem cell factor(SCF) and interleukin-3 from bone marrow cell, interleukin-10 (IL-10), and interferon-$ {\gamma}$(INF-${\gamma}$) from splenic cell, and NOSⅡ gene from macrophage using by RT-PCR. Also proliferation of immune cell was analyzed using 3H-thymidine uptake and flow cytometery in splenic cells. The results were obtained as follows ; 1. The total number of WBC, RBC and PLT was increased in the KGBT treated group than in the control group. 2. In vitro, the proliferation of splenic cells was increased in normal, control, and KGBT treated group. And Administration of KGBT was reduced the cytotoxicity by CTX. 3. In bone marrow cell, the gene expression of immune regulatory factor that associated with hematopoiesis, such as TPO, SCF, and IL-13 was increased in the KGBT treated group than control. 4 The titer of hemagglutinin and hemolysin was increased in the KGBT treated group than control. 5. In analysis of positive leucocytes from splenic cell of BALB/c mice, the subpopulation percent of CD4+, CD8+,and CD19+ was increased in the KGBT treated group than control. 6. The expression of IL-10 gene was reduced in the KGBT treated group than control, whereas the expression of INF-${\gamma}$ was increased in the KGBT treated group. 7. In macrophage, the production of NO and gene expression of NOSH was increased in the KGBT treated group than control. 8. After infection of EMC virus, the survival time of infected mice was longer in the KGBT treated group than control.

• Animal cells and systems
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• v.3 no.4
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• pp.399-405
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• 1999

Characteristics of the food isolates and the clinical specimens isolates of E. coli harboring virulence factor and their correlations were analyzed. The predominant serogroup were 08 and 027 in the food isolates and 06 and 018 in the clinical isolates, respectively, showing the different patterns in serogrouping between them. In the test of antibiotic susceptibility, the food isolates were resistant to cephalothin, streptomycin, tetracycline and minocycline, and the clinical isolates were resistant to ampicillin, carbenicillin, streptomycin, cephalothin, trimethoprim/sulfamethoxazole, tetracyclino and minocycline, respectively. It shows that E.coli isolated from food sources and clinical specimens might be correlated. Plasmid profile in the food and clinical isolates showed wide diversity. Especially, large sized plasmid DNA such as 60 MDa, 90 MDa and 120 MDa were observed. The plasmid DNA (60 MDa) containing a gene encoding hemolysin was found in 43% of the food isolates and 35% of the clinical isolates. To study chromosomal homology, PFGE analysis was performed, showing different restriction patterns by Xbal. This result indicates that there were no genetic correlations between the foods and the clinical isolates.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.181-187
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• 1995

The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.