• Food Science and Biotechnology
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• 제17권5호
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• pp.1074-1078
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• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• 대한수의학회지
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• 제55권3호
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• pp.175-179
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• 2015

Proteases play important roles in parasite development and host parasite interactions. The protease of Kudoa spp. has been recognized as a key factor of severe proteolysis of fish muscle post-mortem; however, there is little information available regarding the protease of Kudoa (K.) septempunctata, which was recently identified as a cause of food poisoning in humans. The present study was conducted to isolate and characterize proteases to elucidate the type of protease contained in the parasite and determine the optimal pH for protease activity. We confirmed the cysteine protease and metalloprotease produced by K. septempunctata. While the cysteine protease showed optimal activity at pH 5 that decreased rapidly with increasing pH, the optimal activity of metalloprotease was pH 7, and it remained stable from pH 6 to pH 8. These results indicate that the pH of cysteine protease is not proper for fish muscle postmortem, and that metalloprotease can act in human intestines. Overall, the present study provides important information that improves our understanding of the role of protease physiology and the subsequent food poisoning caused by K. septempunctata.

• 대한수의학회지
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• 제47권3호
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• pp.299-302
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• 2007

Neoheterobothrium hirame (N. hirame) is a large blood-feed gill-worm infecting the highly prized olive flounder. The present study was reported the occurrence and elimination of Neoheterobothrium infection from young cultured oliver flounder in the western coast of Korea. Flounder (weight 18-25 g, length 10-15 cm) were obtained from a cultured farm at Taean of Korea at May 2006. A lot of flounder died with serious anemia. We isolated N. hirame from the buccal cavity wall of dead flounder. Adult parasites were 5-15 mm in total length, with 4 pairs of clamps on the pedunculated haptor and isthmus region embedded in host tissue, while immature and sub-adults were identified the attachment to the gill filaments, rakers and arches with the clamps. All fish with infection were treated with 8% NaCl-supplemented seawater for 1 and 10 min at $22^{\circ}C$, respectively. The significant reduction in mortality (6.7%) was observed among fish treated with 8% salt water for 10 minutes, when compared with that of non-treatment group (100%).

• 한국식품위생안전성학회지
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• 제7권2호
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• pp.107.2-119
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• 1992

Fish pathology is one of the main scientific bases upon which this expansion in aquaculture has been dependent and requires a wide knowledge of the environmental constraints, the physiology and characteristic of the various pathogens, the responses of the host, and the methods by which they may be controlled. The primary disease and parasite problems in aquaculture animals related to viral, bacteria, fungal and protozoan epizootics. Parasitic nematodes, trematodes and cestodes are commonly found in aquaculture animals, but seldom are they present in concentrations sufficient to cause significant problems, When an epizootic does occur and chemical treatment is indicated, the appropriate chemical must be selected an properly applied. We have antibiotics, sulfa, nitrofuran and other chemicals for treatment of fish diseases, Some may be mixed with the feed during formulation, added to the pellets of feed as a surface coating, given in the form of an injection or used as a bath. Even though a drug or chemical has been officially approved for use in aquaculture, the substance should never be used unless there is a clear need, Some of the reasions for this view are as follows: (1) the constant use of antibiotics can leak to the development of resistant strains of bacteria, (2) biofilter efficiency may be impaired or destroyed by chemicals added to closed recirculating water systems, and(3) the injudicious use of chemical can have a damaging effect on the environment as well as on human.

• Journal of Species Research
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• 제6권spc호
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• pp.8-14
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• 2017

Taeniacanthid copepods Anchistrotos kojimensis Do and Ho, 1983 were collected from the branchial cavities of stichaeid fish, Ernogrammus hexagrammus (Schlegel) and yellowfin goby, Acanthogobius flavimanus (Temminck and Schlegel) in Korean waters. Here, we provide the first description of a male of Anchistrotos Do and Ho, 1983. A close comparison of the specimens of A. kojimensis collected from Korea with the original description revealed differences in the adult female: (1) the caudal ramus bears seven setae (seta I minute); (2) the maxillule with small knob-like process anteriorly; (3) leg 5 ornamented with patched spinules distally and having row of spinules at base of each spine and distal seta. The first description of the adult male reveals the following features: (1) the distal abdominal somite had rows of spinules anteriorly and near insertion of each caudal ramus; (2) the postantennal process is more elongate than in the female; (3) the basis of maxilliped is with two prosimomedial setae, two longitudinal rows of stout denticles found on posteromedial surface and row of spinules on anteromedial surface; and (4) the second endopodal segment is a strongly curved claw, with a row of stout denticles along a concave margin, two long and one small setae.

• Journal of Species Research
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• 제9권4호
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• pp.325-338
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• 2020

The animal gut is filled with highly diverse microbes associated with host metabolism, physiology, and pathology. However, numerous animal gut microbes have not been cultured or reported. We isolated various bacterial species using culture-dependent approaches during a comprehensive investigation of endangered endemic vertebrate species in the Republic of Korea. A total of 18 unrecorded bacterial species were isolated from the feces of an Oriental stork (Ciconia boyciana), and from the intestinal tracts of a cobitid fish (Kichulchoia multifasciata) and a Korean splendid dace (Coreoleuciscus splendidus). Based on a phylogenetic analysis of 16S rRNA gene sequences, we discovered species belonging to the phyla Actinobacteria (eight species), Firmicutes (seven species), Proteobacteria (two species), and Bacteroidetes (one species). Based on their high 16S rRNA gene sequence similarities (>98.7%) and formation of monophyletic clades with type species, each species was classified into an independent and predefined bacterial species. Gram-stain reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and NIBR IDs for each species are described in the species description section.

• Parasites, Hosts and Diseases
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• 제54권5호
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• pp.617-623
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• 2016

An excavation of the Vesakoyakha II-IV and Nyamboyto I burial grounds was conducted during the 2014 field season, and soil samples from intact burials dating from the 19th and 20th centuries, respectively, were analyzed to determine interactions between parasites and host/vectors. Considering the discovery of Diphyllobothrium sp. and Taenia sp. eggs in soil samples from the pelvic region, diphyllobothriasis was the most frequent helminthic infection among the Taz Nenets. The Nyamboyto Nenets mainly consumed uncooked fish, while the Vesakoyakha Nenets had a bigger variety in food choices, including reindeer meat. Nenets children were given raw fish from early childhood. The paleoparasitological results corroborate rare ethnographic records about the consumption of uncooked reindeer cerebrum which led to beef tapeworm helminthiases. This is the first parasitological report of helminthic diseases among the Taz Nenets, and, as such, it provides insight into their subsistence activities and food patterns and broadens our understanding of their health condition.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.127-134
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• 2019

Sinuolinea capsularis Davis, 1917 is myxosporean that infect the urinary system of the host fish. Insufficient morphological and molecular data of S. capsularis exits, and it is therefore difficult to make an accurate identification of the parasite. We tried a series of morphological and molecular analysis to identify an myxosporean isolated from urinary bladder of cultured olive flounder, Paralichthys olivaceus, from Jeju island in the Republic of Korea. Some of them were observed under a light microscope and SEM, and remain samples were used molecular and phylogenetic analysis. Mature spores were subspherical, measuring $13.9{\pm}0.6{\mu}m$ in length and $13.8{\pm}0.8{\mu}m$ in width. Two spherical polar capsules on opposite sides in the middle of the spore had a diameter range of $4.3{\pm}0.4{\mu}m$. Scanning electron microscopy revealed that spores a severely twisted the suture line. By the morphological comparison and analysis, it was identified as S. capsularis. In addition, we obtained the partial 18S rDNA of S. capsularis and first registered it in NCBI. Phylogenetic analysis showed that S. capsularis clustered with Zschokkella subclade infecting the urinary system of marine fish, and it supported the infection site tropism effect on phylogeny of marine myxosporeans as well as the origin of Sinuolinea is not monophyly.

• Fisheries and Aquatic Sciences
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• 제25권1호
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• pp.40-48
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• 2022

Seahorses, which have been cultivated since the 2000s, are economically very important. Gas bubble disease (GBD) is a significant concern in the cultivation of seahorses; therefore, this study aimed to determine the cause of GBD-induced death in two species of Syngnathidae (Syngnathus schlegeli and Hippocampus haema). Rod-shaped bacteria were observed histopathologically and identified as Vibrio splendidus by conventional and real-time PCR analyses. The lethality of V. splendidus varies depending on the host's immune status, and the disease can be prevented through water quality management or improvement of the breeding environment. In this study, the GBD lesions (gas bubbles) were observed at 12℃, 8.0 mg/L of dissolved oxygen, 30 ppt of salinity, and pH 7.7. In addition, rod-shaped bacteria, infiltration of inflammatory cells, and extensive serous exudate were confirmed in the lesions where gas bubbles were found. PCR analysis was able to detect V. splendidus, possibly a secondary infection of the immunocompromised syngnathid fish. Understanding the risk of immunity control and the correlation between these lesions and causal agents will be of great help to the aquaculture industry and the ornamental fish market.

• 한국어병학회지
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• 제26권2호
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• pp.65-75
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• 2013

실험실에서 온도 별로 스쿠티카충을 배양한 데이터(Table 1)를 사용 스쿠티카충 개체군의 변화율(1.2)과 성장 방정식(1.3)을 in vitro 조건에서 구했다. 이 모델에서는 스쿠티카충의 증가모델 식은 로지스틱 증가함수로 두 가지 온도에서의 스쿠티카충의 증가율 매개변수를 구하였고, 기생충으로 인한 숙주인 넙치에 치명적일 수 있는 기생충의 임계밀도를 구하였다. 또 다른 데이터는 같은 온도에서 스쿠티카충 수를 다양하게 넙치의 복강에 주사하는 그룹과 동일한 스쿠티카충 수를 복강에 주사한 후 온도를 다르게 한 두 그룹의 스쿠티카충의 감염으로 폐사한 실험데이터(Table 2)에 근거하여 넙치의 감염에서 폐사가 되는 시스템 식(1.5)을 세웠다. 정리에서는 감염된 넙치와 폐사된 넙치의 미분방정식계는 감염넙치와 폐사 넙치와의 평형점을 찾고 그 평형점에 대한 안정성과 불안정성을 설명하였다. 각 온도에서의 매개변수를 사용하면 방정식 (1.6)은 시간에 대해 넙치의 누적 폐사량을 알 수 있는 방정식이다. 이 논문에서는 다양한 초기값 $P_0$값에 따른 넙치의 폐사를 중심으로 보았으므로 온도와 $P_0$가 동시에 넙치폐사에 어떠한 관계를 갖는 연구를 하기에는 제약을 갖고 있다. 이 연구의 제한점에서 언급했듯 실험을 여러 번 시행한 것이 아니기 때문에 단지 근사적인 값으로 이해를 해야 한다. 또한 넙치의 면역력을 알 수 있다면 기생충으로부터 저항력을 연구하는데 오차를 좀 더 줄인 근사치를 구할 수 있을 것을 기대할 수 있을 것이다.