• 한국어병학회지
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• 제24권3호
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• pp.279-287
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• 2011

Transcriptional response patterns of mud loach (Misgurnus mizolepis; Cypriniformes) hepcidin, a potential ortholog to human hamp1, in response to experimental challenges with non-pathogenic and pathogenic bacterial species were analyzed based on the semi-quantitative reverse transcription-PCR assay. Mud loach hepcidin transcripts were much more preferentially induced by pathogenic bacterial species (Edwardsiella tarda and Vibrio anguillarum) causing apparent pathological symptoms than by non-pathogenic species (Escherichia coli and Bacillus thuringiensis) displaying neither clinical signs nor mortality. However in overall, the induced amounts of hepcidin transcripts were positively related with the number of bacterial cells delivered in both pathogenic and non-pathogenic bacterial species. Inducibility of hepcidin transcripts were variable among three tissues examined (liver, kidney and spleen) in which kidney and spleen were more responsive to the bacterial challenge than liver. Time course expression patterns of hepcidin mRNAs after challenge were different between groups challenged with pathogenic and non-pathogenic species, although the overall pattern of hepcidin expression was in accordance with that generally observed in battery genes appeared during early phase of inflammation. Fish challenged with E. coli (non-pathogenic) showed the significant induction of hepcidin transcripts within 24 hr post injection (hpi) but the level was rapidly declined to the basal level either at 48 or 96 hpi. On the other hand, hepcidin transcript levels in E. tarda (pathogenic)-challenged fish were continuously elevated until 48 hpi, then downregulated at 96 hpi, although the level at 96 hpi was still significantly higher than control level observed in non-challenged fish. This expression pattern was consistent in all the three tissues examined. Taken together, our data indicate that hepcidin is tightly in relation with pathological and/or inflammation status during bacterial challenge, consequently providing useful basis to extend knowledge on the host defensive roles of hepcidin under infectious conditions in bony fish.

• 한국임상수의학회지
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• 제19권1호
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• pp.14-18
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• 2002

An epidemiological study was performed to evaluate the state of fish diseases between aquaculture fishes in the area of southern Kyeongnam, especially Tongyeong-si, Geoje-si, and Goseong-gun. Examination for a total of 91 cases was carried out for a variety of fishes, including Japanese flounder(Paralichthys olivaceus), rock fish (Sebastes schlegeli), sea bass (Lateolabrax japonicus), sea breams(Pagrus major), and red drum (Sciaenops ocellatus) from November, 1999 to October, 2001. The investigation resulted in exploring 155 infectious diseases, including 62 Vibriosis, 16 Edwasiella infection, 11 Streptococcosis, 7 Pseudotuberculosis, 15 Scuticociliatida infection, 20 Gill flukes, and 9 Trichodiniasis. When the infections were classified according to fish species, Japanese flounder was infected by 30 Vibrio spp., 16 Edwardsiella tarda, 6 Streptococcus spp., 12 Scuticociliatida infection. In case of sea bass, 10 Vibrio spp. was able to isolate out of 10 outbreaks, on the other hand, rock fish was dominantly infected by gill flukes since it was observed 12 out of a total of 20 cases. With reference to seasonal fluctuation, Vibrio spp. infection was continually observed through all seasons but Edwardsiella septicaemia, Streptococcosis and Pseudotuberculosis was mainly isolated in summer and autumn when the water temperature was raised high. Scuticociliatida infection was frequently occurred from late autumn to early spring but gill flukes were watched all the year regardless of temperature. As regards, multiple infection, 47 out of 91 cases was Identified to have involved in more than 2 pathogens, especially Vibrio spp. was highly mixed with other pathogens since 42 out of 47 cases was mixed with Vibrio spp.

• 생명과학회지
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• 제23권2호
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• pp.299-305
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• 2013

Paenibacillus는 호기성의 내생포자를 형성하는 그람양성균으로써 이전에는 Bacillus로 분류되었다. Paenibacillus sp. CK214 균주는 LB agar 평판배지에서 높은 swarming 운동 능력을 가지고 Paenibacillus 특유의 집락 형태를 나타내었지만 glucose가 첨가된 평판배지에서는 운동 능력을 상실하였다. 투과전자현미경(TEM)을 이용하여 glucose 조건에 따른 CK214 균주의 편모를 관찰하면 LB agar 평판배지에서 배양한 CK214 균주는 주모성의 편모를 가지는 반면 glucose를 첨가한 평판배지에서 배양한 CK214 균주의 경우 주모성 편모가 나타나지 않는 것을 확인할 수 있었다. 물리적 충격과 원심분리를 통해 분리한 CK214 균주의 filament 구성 단백질을 SDS-PAGE를 통해 확인하였으며, 약 29 kDa 크기의 단일 단백질 밴드가 나타났다. Edwardsiella tarda 균주의 flagellin 단백질에 특이적인 항체를 이용한 immunoblotting 수행 결과, 이 단일 단백질 밴드는 flagellin 단백질임이 확인되었다. Glucose조건에 따른 CK214 균주의 flagellin 단백질의 발현을 단백질 수준에서 관찰한 결과, glucose가 첨가된 조건에서 생장한 CK214 균주에서의 flagellin 단백질 발현이 glucose가 없는 조건일 때에 비해 감소하는 것을 확인할 수 있었다.

• 한국어병학회지
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• 제10권2호
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• pp.75-86
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• 1997

어류의 감염 조직으로부터 edwardsiellosis의 원인균인 Edwardsiella tarda를 whole cell 자체로 직접 검출할 수 있는 solid phase ELISA법을 연구하였다. A. hydrophila ATCC7966, V. anguillarum HUFP5001, Y. ruckeri 11-4, E. ictaluri 및 Streptococcus sp. NG8206 등의 어병세균에 대해 ELISA법으로 실시한 교차반응 분석에서 A. hydrophila ATCC7966 균주와 V. anguillarum HUFP5001 균주가 E. tarda Edk-2에 대한 토끼 항혈청에 대해 높은 교차반응을 나타내었으나, 항혈청을 A. hydrophila ATCC7966 FKC로 흡착시킴으로써 교차반응을 제거할 수가 있었다. 그러나, 응집항체가 측정 결과와는 달리, ELISA 분석에서는 E. tarda 분리 균주간의 교차반응이 매우 높은 것으로 나타났다. Tissue homogenate내에 있는 항원을 검출함에 있어, 조직내의 지질이나 단백질 성분이 함께 분석용 plate에 coating되어 감도가 훨씬 감소하므로 ELISA법의 적용을 위해서는 감염 조직의 homogenate를 PBS에 100배 이상 희석한 후 진단을 실시해야 하는 것으로 나타났다. Tissue homogenate내에 있는 생균을 항원으로 하여 직접 검출할 때에는 검출한계가 $1{\times}10^3$ cells/ml로 나타나 FKC 항원의 사용에 비하여 더 증가된 감도를 보여주었다. 결론적으로 본 ELISA법은 양식장에서 발생한 edwardsiellosis를 진단함에 있어서 특이적이고 신속하며 민감한 방법으로 확인되었다.

• 한국양식학회지
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• 제22권1호
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• pp.51-55
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• 2009

Transcriptional response of the second isoform of glyceraldehyde (GAPDH-2) to infectious challenges using various bacterial species and the rockbream iridovirus (RBIV) was examined in the spleen of the barred knifejaw (Oplegnathus fasciatus). Bacterial challenges of the juvenile barred knifejaws with Escherichia coli, Edwardsiella tarda, Vibrio anguillarum and Streptococcus iniae resulted in the significant elevation of the GAPDH-2 transcripts in the spleen up to 12-fold relative to that in the non-challenged controls (PBS-injected). In addition, the barred knifejaw fingerlings injected with RBIV stock also represented the highly upregulated mRNA expression of the GAPDH-2 up to more than 20-fold when compared to that of control fingerings. Results obtained from this study strongly suggest that the GAPDH-2 is no longer a housekeeping glycolytic protein and rather than that it might be associated with immune-relevant cellular activities. From this finding, the traditional dogma for the use of GAPDH as an invariant standard for gene expression assays should be carefully revised depending on the kinds of biological stimulations applied in this species.

• 한국동물위생학회지
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• 제36권4호
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• pp.297-301
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• 2013

The present study was to investigate anti-microbial effects of curcumin on major bacterial pathogens for farmed fish, such as Aeromonas hydrophila, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida, Edwardsiella tarda, Vibrio vulnificus, V. paraheamolyticus using disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. In disc diffusion test, curcumin exhibited concentration-dependent antimicrobial activities to all bacteria pathogens used in the study. Antimicrobial effects of curcumin was found differently depending on bacterial species when determined by MIC or MBC tests. For examples, E. tarda and A. hydrophila was respectively the most sensitive bacterium for bacteriostatic and bacteriocidal effect of curcumin. Collectively, curcumin could be a potential natural drug for controlling pathogenic bacteria in the aquaculture industry.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

• 한국수산과학회지
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• 제44권2호
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• pp.126-140
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• 2011

Genetic determinants of two metallothionein isoforms (MT-A and MT-B) were isolated and characterized from the perciform species, rockbream (Oplegnathus fasciatus). Rockbream MT-A and MT-B shared a high degree of homology at amino acid levels with representative orthologs from other perciform species, especially with respect to the conserved cysteine residues. At the genomic level, both MT-A and MT-B genes represent a tripartite structure typical of vertebrate MT genes. However, rockbream MT-B showed unusually large introns (1.2 kb and 0.8 kb for intron I and II, respectively), a phenomenon that has rarely been seen in other vertebrate MT genes. MT-A and MT-B transcripts were ubiquitously detected in a wide array of tissues, wherein brain and eye showed the highest basal expression levels, and the fin exhibited the lowest expression of both isoforms. The basal expression of MT-A in most tissues was significantly higher (ranging from 4- to 10-fold) than that of MT-B. Upon heavy metal exposures to Cd, Cu or Zn at 25 ppb for 48 h, MT-A and MT-B transcripts in the liver were significantly activated by Cd and moderately by Zn. On the other hand, exposure to Cu did not result in alterations of MT-A, nor in the significant suppression of MT-B. Following bacterial challenges with Escherichia coli, Edwardsiella tarda or Streptococcus iniae, MT isoforms in the liver, kidney and spleen were highly modulated and exhibited a pattern that was dependent on the bacterial species, tissues and isoforms. These results suggest that the two MT isoforms could be taken into account as potential indicators of metal toxicity and immune perturbations of this aquaculture-relevant species.

• 한국해양바이오학회지
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• 제14권2호
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• pp.86-92
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• 2022

In this study, the antibacterial activity of major compounds obtained from domestic plant essential oils was investigated against four species of fish pathogenic bacteria, namely, Edwardsiella tarda, Vibrio harveyi, Streptococcus iniae, and Streptococcus parauberis. We observed that α-terpineol and eucalyptol showed high antibacterial activity against S. iniae, whereas α-terpineol and β-linalool showed high antibacterial activity against S. parauberis. The antibacterial activity of eucalyptol and β-linalool was significantly high against E. tarda, and α-terpineol and β-linalool exerted antibacterial activity against V. harveyi. All compounds showing significant antibacterial activity also exhibited high solubility in water (≥1,000 mg/L). In contrast, compounds such as α-limonene and α-pinene with low water solubility showed significantly low antibacterial activity against all bacteria. These findings can be utilized further to estimate the antibacterial activity of compounds isolated from plant essential oils for the prevention of fish disease.

• 한국어병학회지
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• 제37권1호
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• pp.37-48
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• 2024

This study evaluated in vitro antimicrobial properties of Bacillus subtilis KCTC 1326 as an environmentally friendly alternative to antibiotics. B. subtilis KCTC 1326 was characterized on biochemical properties and antibiotics susceptibility. It exhibited antimicrobial effects against all 12 species of fish bacteria used in this experiment. Among them, the largest antibacterial zone was observed for Streptococcus parauberis (34 mm), while the smallest antibacterial zone was observed for Citrobacter freundii (8 mm). Additionally, in the co-culture inhibitory assay of B. subtilis and Edwardsiella piscicida, the growth of E. piscicida was suppressed with increasing concentrations of B. subtilis KCTC 1326, with complete inhibition observed at 107 and 108 CFU/mL of B. subtilis KCTC 1326 after 24 hours of incubation. Moreover, at 48 hours of incubation, the growth of E. piscicida was inhibited across all concentration ranges of B. subtilis KCTC 1326. Therefore, this study indicated the utilizing of B. subtilis KCTC 1326 as an antimicrobial for controlling fish bacterial diseases.