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Jeong Y.-U.,Jeju National University | Subramanian D.,Jeju National University | Jang Y.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Kim D.-H.,Jeju National University | And 4 more authors.
Archives of Polish Fisheries | Year: 2016

Streptococcus iniae is a causative agent of hemorrhagic septicemia in olive flounder, Paralichthys olivaceus, in Korea, resulting in serious economic losses. As a preventive measure, M VAC INIAE (Mastuken, Japan) was prepared from the S. iniae F2K strain and tested against the SI-36 strain prevalent on flounder fish farms on Jeju Island, Korea. F2K had a serotype of 38 (-) and SI-36 38 (+). The vaccine recognized both serotypes. It showed a very high effective immune response against S. iniae; the challenge test using the S. iniae SI-36 strain resulted in a relative percent survival (RPS) of 85.7-87.0% 2 weeks after vaccination and 71.0-80.0% 6 months after vaccination. Field vaccination and clinical challenge tests were performed at local Jeju aquafarms with S. iniae SI-36. These showed significantly reduced cumulative mortality when compared to the control group with RPS rates that ranged between 71-80%. Hence, the present study suggests that this vaccine showed a significant immune response against S. iniae and could be applied in commercial aquafarms as a therapeutic agent against β-hemolytic streptococcosis in cultured P. olivaceus. © 2016 Archives of Polish Fisheries.


Jang Y.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Subramanian D.,Jeju National University | Heo M.-S.,Jeju National University
Vaccine | Year: 2014

Formalin killed Pseudomonas anguilliseptica bacterial vaccine was prepared and administered to farm reared olive flounder, Paralichthys olivaceus reared at 17°C and 20°C for 4 weeks. Non-vaccinated fishes (n=150) served as positive control. Vaccinated fishes were divided into two groups (n=150 each in replicate). Both the vaccinated and non-vaccinated fishes were challenged intraperitoneally with P. anguilliseptica (1×107CFUml-1) isolates and PBS (negative control). Fishes were sampled from zero hour post injection (hpi) for 28 days (each hour and each day); the mean percent mortality and relative percent survival (RPS) were calculated for the challenged and control groups. The vaccinated fishes had a significant increase in RPS (69 and 89, respectively); the percentage mortality declined from 83±0.6 and 74±0.7 in challenged and control fishes to 25%±0.8% and 8%±0.8% in vaccinated and challenged fish groups, respectively. The immune gene expression assay was analyzed using real-time PCR. Vaccinated fishes registered a significant increase in the expression of TNFR-1, FasL, IRF7, TLR2, IL-1b and CD40 gene transcripts when compared to the control group. The upregulation of these genes along with the increased RPS values suggest that the formalin-killed cells of P. anguilliseptica could play an important role in immunizing olive flounder against P. anguilliseptica. © 2014 Elsevier Ltd.


Subramanian D.,Jeju National University | Jang Y.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Kim D.-H.,Jeju National University | Kang B.-J.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Heo M.-S.,Jeju National University
Fish and Shellfish Immunology | Year: 2013

The objective of this study was to evaluate the effect of dietary supplementation of a Rubus coreanus ethanolic extract on immunostimulatory response in white leg shrimp Penaeus vannamei. Shrimps with an average initial weight of 0.5±0.04g were collected and acclimatized for 10 days. Four experimental diets including a control diet, a probiotic diet and 0.25 and 0.5% of R. coreanus ethanolic extract. (RcEE) diets were used to feed the shrimps. After 8 weeks of culture, shrimp fed with probiotic and 0.25% RcEE diet had showed significant enhancement in the growth while shrimp fed with 0.5% RcEE diet showed significantly increased expression of immune genes and antioxidant enzymes activities. One week of challenge experiments for all the four diets fed shrimps showed decreased cumulative mortality in the 0.5% RcEE diets fed shrimps, when compared with the probiotic and 0.25% RcEE diet fed shrimp groups. The results indicates that R. coreanus ethanolic extract could be used as a herbal immunostimulant forshrimps to increase its immunity and disease resistance against the bacterial pathogen, Vibrio alginolyticus. © 2013 Elsevier Ltd.


Lee H.-W.,Korea Basic Science Institute | Lim N.-L.,Korea Basic Science Institute | Cho K.,Korea Basic Science Institute | Yang H.Y.,Korea Basic Science Institute | And 8 more authors.
Food Chemistry | Year: 2014

The sea cucumber Stichopus japonicus lives in a variety of marine habitats and is an important cultivated edible aquatic species in East Asia. In this study, S. japonicus, collected from the sea near Jeju Island of Korea, was lyophilised or vacuum-dried and then analysed by gas chromatography-mass spectrometry (GC-MS) or inductively coupled plasma mass spectrometry (ICP-MS). The GC-MS profiles of vacuum-dried and lyophilised samples differed. Based on direct injection and static headspace analysis, 37 volatile organic compounds (VOCs) were identified in vacuum-dried samples and 33 VOCs were identified in lyophilised samples. Therefore, the odour of vacuum-dried sea cucumber is thought to be due to the presence of various VOCs that are absent in lyophilised sea cucumber. According to ICP-MS analysis, the levels of 15 inorganic elements were slightly higher in lyophilised samples than in vacuum-dried samples. The results of the inorganic and organic chemical analyses provide information about the composition of dried sea cucumber. © 2013 Elsevier Ltd. All rights reserved.


Jang Y.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Dharaneedharan S.,Jeju National University | Kang B.-J.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Heo M.-S.,Jeju National University
Israeli Journal of Aquaculture - Bamidgeh | Year: 2014

Viral hemorrhagic septicemia virus (VHSV) was isolated from farmed olive flounder (Paralichthys olivaceus). The viral N-gene was amplified by reverse transcriptase PCR, cloned, and sequenced for phylogenetic analysis to identify the genotype (I-IV). Virus isolates were cultured on Epithelioma papulosum cyprini cell line and, after completion of the cytopathic effects, the supernatant was collected and used to challenge virus-free flounder. The infected founder were reared in 16°C, 21°C, or 25°C, and compared to an unchallenged control. Virus titration was measured in the head kidneys, spleens, livers, brains, muscles, and gills of challenged fish using real-time quantification of the VHSV G-gene. Phylogenetic analysis confirmed that the isolates were VHSV Genogroup IV. The VHSV-challenged fish in the 16°C group showed 100% mortality with significantly increased expression of viral G-gene mRNA in the spleen, compared to fish reared in other temperatures and the control fish, suggesting that fish reared in 16°C are more susceptible to VHSV infection.


Kang B.-J.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Dharaneedharan S.,Jeju National University | Jang Y.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Won S.-H.,Jeju Special Self Governing Province Ocean and Fisheries Research Institute | Heo M.-S.,Jeju National University
Fish Pathology | Year: 2015

Pseudomonas anguilliseptica is a dreadful fish pathogen causing severe problem in olive flounder Paralichthys olivaceus farms in Jeju Island, Korea. Diagnosis of this disease required a time-consuming and labor intensive culturing step. Hence more rapid and sensitive detection methods are needed. In this study, a TaqMan probe real-time PCR-based detection assay targeting the 16S rRNA gene of P. anguilliseptica was developed. This assay was specific for P. anguilliseptica and sensitive in detecting as little as 300 pg P. anguilliseptica genomic DNA and 2.4 × 100 plasmid copie. Challenge experiments of healthy flounder with a virulent strain of P. anguilliseptica confirmed the specificity of the designed molecular probe for detection of P. anguilliseptica. This assay represents a significant approach for diagnosing P. anguilliseptica infection in olive flounder. © 2015 The Japanese Society of Fish Pathology.


PubMed | Jeju National University and Jeju Special Self Governing Province Ocean and Fisheries Research Institute
Type: Journal Article | Journal: Vaccine | Year: 2014

Formalin killed Pseudomonas anguilliseptica bacterial vaccine was prepared and administered to farm reared olive flounder, Paralichthys olivaceus reared at 17 C and 20 C for 4 weeks. Non-vaccinated fishes (n=150) served as positive control. Vaccinated fishes were divided into two groups (n=150 each in replicate). Both the vaccinated and non-vaccinated fishes were challenged intraperitoneally with P. anguilliseptica (110(7) CFU ml(-1)) isolates and PBS (negative control). Fishes were sampled from zero hour post injection (hpi) for 28 days (each hour and each day); the mean percent mortality and relative percent survival (RPS) were calculated for the challenged and control groups. The vaccinated fishes had a significant increase in RPS (69 and 89, respectively); the percentage mortality declined from 830.6 and 740.7 in challenged and control fishes to 25%0.8% and 8%0.8% in vaccinated and challenged fish groups, respectively. The immune gene expression assay was analyzed using real-time PCR. Vaccinated fishes registered a significant increase in the expression of TNFR-1, FasL, IRF7, TLR2, IL-1b and CD40 gene transcripts when compared to the control group. The upregulation of these genes along with the increased RPS values suggest that the formalin-killed cells of P. anguilliseptica could play an important role in immunizing olive flounder against P. anguilliseptica.

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