• Journal of fish pathology
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• v.19 no.2
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• pp.173-181
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• 2006

Miamiensis avidus is a scuticociliate causing mortality in olive flounder Paralichthys olivaceus. To evaluate immune response of olive flounder against M. avidus, 2.6×106cells/fish of Formalin killed cell (FKC) was intraperitoneally (i.p.) injected, and 2.4 × 106cells/㎖ of sonicated FKC was immersion immunized to 14.9 cm (26.8g) fish. Fish were immunized 2 times with 2 weeks intervals. Antiserum from immunized fish caused agglutination and immobilization of the ciliate. In ELISA test, immunized group exhibited higher titers than control group. In addition, i.p. immunized fish showed higher phagocytic ratio, phahgocytic index and chemotaxic activity. To evaluate in vivo efficacy of FKC on fish, 1.43 × 105cells/fish was i.p.. injected, and 2.2 × 105 cells/㎖ of sonicated cell was immersed into 8.6cm (6.3g) fish. After 2 times immunization with 2 weeks intervals, fish were infected with 2.0 × 104 and 2.0 × 103 cells/ml of live ciliates by immersion. After 3 weeks, cumulative mortality was lower in the i.p. immunized group and mortality was delayed in immersion immunized group. In conclusion, specific immune response of oliver flounder against M. avidus was elevated after immunization and these immune response may prevent and/or delay for the M. avidus infection to olive flounder.

• Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.52-63
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• 2000

Non-specific reaction has been a problem in doing, especially, research and diagnosis for infectious agents. Avidin-biotin-peroxidase complex (ABC) techniques has widely been used to amplify a reaction. Photobacterium damse1a subsp. piscicdia (formerly Pasteurella piscicida) exhibited a capacity to bind with streptavidin non-specifically. The band, estimated 26 K Da in Western blotted paper, was blocked with biotin but incompletely. In an attempt to explore an involvement of the non-specific substance in attaching piscine cells, cell attachment test performed using anti- Ph. d. subsp piscicida sera raised mouse and rabbit exhibited slightly blocking effects for Mediterranean (1736) and significantly for Japanese (Sp 92144) isolate. Biotin decreased the attachment ability significantly for Sp92144 but it was not effective to 1736. Both isolates showed greatly enhanced attachment ability with poly-L-lysin. The non-specific binding substance was contained in bacterial extracellular products (ECPs). The substance was able to purified with 2-imminobiotin affinity column, the purified substance appeared to have 4 bands in silver staining, and had a carbohydrate branch. This purified substance showed cytotoxic effects selectively between 5 piscine cell lines. Moreover, it stimulated rainbow trout macrophage in terms of reduction of cytochrome cas well as yeast phagocytosis, significantly.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.2
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• pp.165-173
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• 2012

Nationally, flatfish vaccination has been performed manually, and is a laborious and time-consuming procedure with low accuracy. The handling requirement also makes it prone to contamination. With a view to eliminating these drawbacks, we designed an automatic vaccine system in which the injection is delivered by a Cartesian coordinate robot guided by a vision system. The automatic vaccine injection system is driven by an injection site location algorithm that uses a template-matching technique. The proposed algorithm was designed to derive the time and possible angles of injection by comparing a search area with a template. The algorithm is able to vaccinate various sizes of flatfish, even when they are loaded at different angles. We validated the performance of the proposed algorithm by analyzing the injection error under randomly generated loading angles. The proposed algorithm allowed an injection rate of 2000 per hour on average. Vaccination of flatfish with a body length of up to 500mm was possible, even when the orientation of the fish was random. The injection errors in various sizes of flatfish were very small, ranging from 0 to 0.6mm.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.167-179
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• 2023

The rifampicin-resistant strain E9-302 of Edwardsiella ictaluri strain 669 (WT) was generated by continuous passage on BHI agar plates containing increasing concentrations of rifampicin. E9-302 was attenuated significantly by 119 times to zebrafish Danio rerio compared to WT in terms of the 50% lethal dose (LD₅₀). Zebrafish vaccinated with E9-302 via intraperitoneal (IP) injection at a dose of 1 × 10³ CFU/fish had relative percentage survival (RPS) rates of 85.7% when challenged with wild-type E. ictaluri via IP 14 days post-vaccination (dpv). After 14 days of primary vaccination with E9-302 via immersion (IM) at a dose of 4 × 10⁷ CFU/ml, a booster IM vaccination with E9-302 at a dose of 2 × 10⁷ CFU/ml exhibited 65.2% RPS against challenge with wild-type E. ictaluri via IP 7 days later. These results indicated that the rifampicin-resistant attenuated strain E9-302 had potential as a live vaccine against E. ictaluri infection. A previously unreported amino acid site change at position 142 of the RNA polymerase (RNAP) β subunit encoded by the gene rpoB associated with rifampicin resistance was identified. Analysis of the whole-genome sequencing results revealed multiple missense mutations in the virulence-related genes esrB and sspH2 in E9-302 compared with WT, and a 189 bp mismatch in one gene, whose coding product was highly homologous to glycosyltransferase family 39 protein. This study preliminarily explored the molecular mechanism underlying the virulence attenuation of rifampicin-resistant strain E9-302 and provided a new target for the subsequent study of the pathogenic mechanism of E. ictaluri.

• Journal of fish pathology
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• v.34 no.1
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• pp.99-104
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• 2021

In this study, we investigated safety and efficacy of a low temperature immunization protocol with NNV in red spotted grouper, Epinephelus akaara and long tooth grouper, Epinephelus bruneus and seven band grouper, Hyporthodus septemfasciatus. Further, growth rate between immunized and naïve fish was evaluated during the experiment to check side effect of immunization. Three grouper species were immunized by immersion method with live NNV at 10^5.0 TCID₅₀/mL at 16.5℃ for 30 min and reared for 120 days at natural sea water temperature. To evaluate growth rate, total length and wet weight was measured 7 times after immunization. Immunized three grouper species were challenged by intramuscular inoculation with NNV at 10^4.2 TCID₅₀/100 µL/fish. Immunization at low temperature with live NNV did not show any clinical symptoms of infection, mortality and inhibition of growth. After challenge, cumulative mortality of naïve seven band grouper, red spotted grouper, long tooth grouper were 45, 10, 20 %, respectively. However no mortality was observed at immunized groupers. Thus, it was demonstrated that immunization at low temperature with live NNV are able to protect three different species of groupers without inhibition of growth.

• Pediatric Infection and Vaccine
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• v.20 no.1
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• pp.41-45
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• 2013

Nontyphoidal Salmonella are gram negative bacilli organism, which may induce systemic infection such as febrile enteritis, bacteremia, and osteomyelitis. Main route of infection is known as food but also possible through reptile, amphibian, and fish raised as pets in the house. There is no known cases report of Salmonella infection through pets in Korea and also rare in the overseas. We report 2 patients who visited Severance children's hospital with chief complaint of fever and diagnosed as nontyphoidal salmonellosis. Each case had a history of raising turtle or tropical fish with possibility of Salmonella infection through these pets. Increasing incidence of raising pet reptile and fish lately, contact precaution and proper prevention and control of Salmonella infection of these pets especially in children under 5 years old are necessary due to higher risk of serious complications of salmonellosis.

• Pediatric Infection and Vaccine
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• v.8 no.1
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• pp.129-133
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• 2001

We experienced one rare case of Diphyllobothrium latum infection in childhood. It was proved by collection of worm after praziquantel treatment. Human diphyllobothriasis is chiefly caused through eating raw or unproperly cooked fish such as trout or salmon. This case was a 5-year old girl residing in Seoul, from whom a kind of pseudophyllidean tapeworm was detected in the feces. She would often eat sushi(raw fish) and had abdominal pain, but not revealed any sign of anemia. Obtained chain of worm segments that sized $0.25{\times}1.25cm$ was compatible with D. latum. Including the present 31 cases, total number of human D. latum infections proven by worms in Korea becomes 32 cases, and total number of child D. latum infections proven by worms in Korea becomes 4 cases.

• Journal of fish pathology
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• v.22 no.3
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• pp.327-334
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• 2009

This study was performed to verify the efficacy and safety of vaccine mixed formalin killed Edwardsiella tarda and formalin killed Streptococcus iniae in olive flounder Paralichthys olivaceus. Sera were obtained from each group at 2, 4, 6 and 8 weeks after vaccination and agglutination titers to E. tarda and S. iniae were determined using the microtiter method. Three weeks after vaccination, the fish challenged by intraperitoneal injection of E. tarda or S. iniae and immunization resulted in a relative percentage survival (RPS) of above 81.0-92.8%. Neither the groups vaccinated nor control groups resulted in significantly reduced weight gain 140 days post-vaccination, but differences between the groups vaccinated and control groups were found at the early days post-vaccination. This results suggest that it is possible to prevent edwardsiellosis and streptococosis after a vaccination without affecting growth of olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.337-345
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• 2015

To investigate the causes of emaciation in cultured olive flounder Paralichthys olivaceus in Korea. We performed histological examinations and polymerase chain reaction (PCR) with a new primer set. In most cases, the most severe emaciation was observed in the abdominal area Using PCR on extracted livers, kidneys, spleens, gills, brains, and intestines, we found that areas around the kidneys and intestines were as almost always positive. In significantly emaciated fish, PCR was positive in all internal organs except the gills. In addition, the homology of 812-bp nucleotide sequences of the 28S rRNA gene was more than 99% in emaciated fish. Partial homology with Myxobolus spp. and Cystodiscus axonis, whose data were obtained from GenBank was 86% and 88%, respectively. Histological examinations detected spores in kidneys and intestines but not in other organs. We also performed cohabitation experiments to determine whether infections could be exchanged among species or only within species. Uninfected olive flounder and red sea bream, Pagrus major, cohabitating with emaciated olive flounder showed 100% and 0% cumulative mortality, respectively. Thus the cause of emaciation in cultured olive flounder of Korea is likely due to a new parasite.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.367-371
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• 2012

To investigate the relationship between metabolic changes in $^1H$-nuclear magnetic resonance (NMR) spectra and fish vaccination, serum was collected from olive flounders treated with a formalin-killed Edwardsiella tarda vaccine and used for $^1H$-NMR metabolite profiling. Principal component analysis and partial least squares were applied to the $^1H$-NMR profile to reduce its complexity and establish class-related clusters. Relative lipid regions were distinguished in vaccinated and non-vaccinated serum. Then, the lipids were extracted from the serum and analyzed. Triolein was identified.