• Korean Journal of Ichthyology
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• v.28 no.3
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• pp.141-146
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• 2016

Experimental infection of rainbow trout Oncorhynchus mykiss with viral hemorrhagic septicemia virus (VHSV, genotype IVa) from olive flounder Paralichtys olivaceus was examined. The cumulative mortalities of three different lot of rainbow trout fry challenged with VHSV ($10^{6.3-7.3}TCID_{50}$/fish) were less than 15%. No difference of virulence was observed in experimental infection using 5 in vivo passaged VHSV and original VHSV. No mortality was observed in seawater-reared rainbow trout (adult) challenged with VHSV ($10^{5.3-6.3}TCID_{50}$/fish) and virus was not detected in the fish. We thus concluded that VHSV from olive flounder has low virulence to rainbow trout fry, but not pathogenic to seawater-rainbow trout (adult).

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.376-382
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• 2013

Objectives: The objectives of this study were to identify the virucidal efficacy against the viral hemorrhagic septicemia virus (VHSV) of an aquatic disinfectant tablet composed of calcium hypochlorite. Methods: Virucidal efficacy was determined through the viability of VHSV contacted with the disinfectant in a viral stock cultured in a fathead minnow cell line. An aquatic disinfectant tablet and VHSV were reacted under distilled water (DW), hard water (HW) or organic matter suspension (OM) conditions. Results: Under DW and HW conditions, VHSV was inactivated with 24,000- and 2000-fold dilutions of the aquatic disinfectant tablet, respectively. With the investigation of the antiviral effect of the disinfectant under OM conditions, VHSV was inactivated with a 16,000-fold dilution of the aquatic disinfectant tablet. Conclusions: The results from this study showed that the aquatic disinfectant tablet was a highly effective disinfectant against VHSV. In the future, a controlled field trial is required to determine whether the use of an aquatic disinfectant tablet will be able to reduce VHSV in a cultured marine fish farm.

• Journal of fish pathology
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• v.30 no.2
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• pp.71-78
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• 2017

The glycoprotein of novirhabdoviruses is known to play a critical role in the determination of host specificity. Viral hemorrhagic septicemia viruses (VHSVs) in different genotypes have different glycoprotein sequences and show different preferences for specific cell lines. In this study, to know whether the glycoprotein is solely responsible for the host cell preference of VHSV, a recombinant VHSV expressing vesicular stomatitis virus (VSV) glycoprotein instead of VHSV IVa glycoprotein (rVHSV-VSV-G) was generated by reverse genetics and inoculated into several fish cell lines, then, cytopathic effect (CPE) and viral growth caused by rVHSV-VSV-G infection were compared with those caused by rVHSV-wild that was previously generated and has the same genomic sequence with wild-type VHSV except a few nucleotides. The plaque numbers of rVHSV-VSV-G were significantly higher in EPC, BF-2 and GF cells than those of rVHSV-wild. However, in HINAE cells (originated from olive flounder), rVHSV-VSV-G titer was significantly lower than rVHSV-wild titer, and both recombinant VHSVs were not grown well in CHSE-214 cells. Although statistical significances were detected in the titers between rVHSV-wild and rVHSV-VSV-G in several cell lines, the cell line-preference order of rVHSV-VSV-G was not different from that of rVHSV-wild. These results suggest that the replacement of VHSV glycoprotein may not completely change host cell preference, and other regions of VHSV might also involve in the determination of host cell preference.

• Pediatric Infection and Vaccine
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• v.11 no.2
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• pp.212-215
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• 2004

The complement system is important in the generation of the normal inflammatory response and in host defense against systemic infection. Therefore, inherited or acquired deficiency of complement is associated with an increased frequency of infection. As a major effector of the complement cascade, the membrane attack complex is responsible for direct complement dependent serum bactericidal activity. Especially late complement component deficiency has a markedly increased risk of meningococcal infection and is subject to recurrent infection. We experienced a patient who had recurrent meningococcal meningitis and septicemia. The patient was 13-years old boy and he had a recurrent episode after 20 months. At second admission, we examined complement level and C7 deficiency was confirmed. He was treated without complication. We report a case of deficiency of C7 with recurrent meningococcal meningitis and septicemia.

• Korean Journal of Veterinary Service
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• v.35 no.1
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• pp.47-52
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• 2012

Crocodile farms are getting popular in Bangladesh in an economic point of view. In one of the farms, some crocodiles were found sick and three of them died between May and July in 2006. This investigation was performed to diagnose the cause of the death. Routine postmortem examination was conducted. Samples were collected in 10% neutral buffered formalin for histopathology and in falcon tube for microbiological study. Additional swabs were collected in nutrient broth. Histopathological and microbiological studies were conducted using routine procedures. In addition Giemsa, Gram and PAS stains were performed to detect the organism in tissues. Grossly, esophagus, trachea, lungs, liver, spleen, heart and kidney were congested. Intestine, rectum and colon were hemorrhagic. Clay colored material was found in colo-rectum. Purulent exudates in lungs and thick and cloudy pericardial fluid in pericardial sac were found. Histologically, multifocal granulomatous inflammation was evident in lung, liver, kidney, intestine and colon with bacterial colonies, fungal spores and hyphae. These bacteria were appeared as Gram negative. Fungal hyphae and spores were detected in liver, lungs and colon by using PAS stain. Bacteriologically, E. coli were isolated from lungs exudates, pericardial fluids and intestinal fluids. Therefore, it can be concluded that 3 crocodiles died due to E. coli septicemia concurrent with mycotic infection.

• Development and Reproduction
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• v.24 no.3
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• pp.187-196
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• 2020

The caspase10 encodes an initiating caspase that plays an important role in the maintaining the cellular homeostasis by regulating the steps involved in the immune response and cell death. We investigated the expression of caspase10 during the different developmental stages and in olive flounder tissues. Caspase10 increased in the late stage of the formation of immune tissue, and high expression was observed in the gills, kidney, skin, and spleen. The current study analyzed the expressional changes of caspase10 in olive flounder infected with viral hemorrhagic septicemia virus (VHSV). One of the major causes of mass mortality, VHSV infection in olive flounder attributes to significant expression of caspase10 in the gills, spleen, skin, and kidneys. The results indicate a close association of caspase10 expression with the immune response to VHSV infection in olive flounder. The observations could form the basis data for exploration of other fish immune system.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.109-116
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• 1987

As a process to establish an effective preventive measure of V. vulnificus septicemia, bactericidal effect of distilled water against V. vulnificus was studied. When about $2.0{\times}10^7\;CFU/ml$ of V. vulnificus was inoculated in distilled water, a dramatic decrease in the number of viable bacteria by 5 to $6LOG_{10}$ was observed in 5 minutes. Bactericidal kinetic curves could be divided into the first rapid killing phase until 1 minute and the later slow killing phase after then, showing the heterogeneity of the bacterial population inoculated. When V. vulnificus was inoculated in saline solutions having various salinities, significant decrease in the number of viable bacteria was noted only at salinities under 0.2%. The higher was the concentration of NaCl, the greater was the degree of protection against osmotic shock. When glucose, NaCl, $MgCl_2$, and $CaCl_2$ were diluted with deionized water to give same osmolarities and V. vulnificus was inoculated in each of them to compare the bactericidal curves plotted during the first 5 minutes after inoculation, the protection efficiencies were in the order of $MgCl_2>CaCl_2{\gg}NaCl{\gg}glucose$. Above results indicate that treatment(or thorough washing) of contaminated sea animals or other products with distilled water can be used as a preventive measure of V. vulnificus septicemia, and divalent cations can protect V. vulnifcus to osmotic shock with high efficiency.

• Journal of fish pathology
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• v.17 no.1
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• pp.1-10
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• 2004

In order to analyse the detection of viral hemorrhagic septicemia virus (VHSV) in marine environment surrounding coastal region of Eastern and Southern sea of Korea, the pools of each organ sample of three fish were taken for virus assay from February to May in 2003. The samples comprised 42, taken from 9 species of marine fishes. The VHSV was detected from chub mackerel Scomber japonicus and striped mullet Mugil cephalus in epithelioma papulosum cyprini (EPC) cells. The identity of the virus was confirmed a reverse transcriptase-polymerase chain reaction (RT-PCR). VHSV has previously been reported from chub mackerel, but not from striped mullet. The new isolates was classified as a member of genogroup I (American type) of VHSV and was closely related to the VHSV KVHS'01-l based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.644-651
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• 2021

Viral hemorrhagic septicemia virus (VHSV) is a fish pathogen responsible for causing enormous economic loss to the aquaculture industry not only in Korea but worldwide. Thus, it is necessary to identify natural compounds that can be used to control the spread of VHSV. In this study, the anti-VHSV activities of five catechol derivatives, i.e., catechol, pyrogallol, 3-methyl catechol, veratrole, and 3-methyl veratrole-extracted from green tea-were assessed. The antiviral activities of these derivatives were found to be dependent on their structure, i.e., the hydroxyl or methoxyl group and their substituent groups-on the benzene ring. Catechol, pyrogallol, and 3-methyl catechol exhibited relatively high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities than veratrole, and 3-methyl veratrole. Moreover, 3-methyl catechol harboring a methyl substituent group increased the viability of the virus-infected cells and resulted in a 2.86 log reduction in the gene copies of VHSV N (per mL) in real-time PCR analysis. In conclusion, the catechol derivatives harboring hydroxyl groups in their benzene ring exhibited higher antioxidant activities than those harboring the methoxyl groups. However, catechol derivatives with a methyl group at the 3'-position of the benzene ring exhibited higher antiviral activity than those harboring a hydroxyl group. To our knowledge, this is the first study to evaluate the relationship between the structure and the anti-VHSV activity of catechol derivatives.

• Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.320-326
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• 2022

Most of the emerging diseases that threaten humans are caused by RNA viruses which are extremely mutable during evolution. The fish RNA virus, viral hemorrhagic septicemia virus (VHSV) can infect a broad range of aquatic animal hosts, but the transmissibility of VHSV to mammals has not been thoroughly investigated. Therefore, our study aimed to investigate the potential adverse effects of VHSV in mammals. Briefly, the survival of VHSV was determined using only minimum essential media (MEM-2) and mammalian SNU-1411 and hepa-1c1c7s cells at 15℃ and 37℃. Mice (Mus musculus, 27.3 ± 1.9 g) were intravenously injected with VHSV (2.37E+05 TCID₅₀·mice^-1) in triplicate. Clinical signs and survival rates were examined at 14 days post-challenge, and infection was confirmed in the surviving mice. The 50% tissue culture infective dose (TCID₅₀) and polymerase chain reaction analysis were used to determine viral titers and the infection rate, respectively. The titer of VHSV suspended in MEM-2 at 15℃ was reduced by only one log after 8 days, whereas the virus maintained at 37℃ was inactivated 8 days post-inoculation (dpi). There were no recognizable cytopathic effects in either SNU-1411 or hepa-1c1c7s cells inoculated with VHSV at 15℃ and 37℃. VHSV in those cell lines at 37℃ was rapidly decreased and eventually inactivated at 12 dpi, whereas virus at 15℃ remained at low concentrations without replication. In vivo experiment showed that there were no signs of disease, mortality, or infection in VHSV-infected mice. The results of this study indicate that it is highly unlikely that VHSV can infect mammals including humans.