• 한국어병학회지
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• 제25권3호
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• pp.231-241
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• 2012

2007년~2011년 하절기에 국내 동 서 남해안과 제주의 육상양식장, 가두리 및 축제식 양식장에서 사육중인 넙치 (Paralichthys olivaceus), 조피볼락 (Sebastes schlegeli), 참돔 (Pagrus major), 흰다리새우 (Litopenaeus vannamei) 의 총 2,413마리에 대하여 세균과 기생충의 감염현황을 조사하였다. 조사기간(2007년~2011년) 사이 어종별 병원체에 대한 감염양상을 종합하면, 기생충과 세균의 단독감염이 혼합 감염에 비하여 비교적 높게 나타났으며, 단독감염 가운데 기생충이 세균보다 감염률이 높은 경향을 나타내었다. 조사기간 동안 넙치, 조피볼락, 새우에서 Vibrio spp. (V. harveyi, V. ichthyoenteri, Vibrio sp.)가 가장 우점종으로 검출된 세균의 위치를 차지하였으며, 참돔에서는 Vibrio sp.와 P. damselae가 우점종 세균으로 검출되었다. 조사기간 동안 가장 우점종으로 검출된 기생충은 넙치에서 스쿠티카충 (M. avidus)과 트리코디나충 (Trichodina sp.), 조피볼락에서 아가미흡충 (M. sebastes), 참돔에서 아가미흡충 (M. tai), 새우에서 섬모충 (Zoothamnium sp.) 으로 나타났다.

• 생명과학회지
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• 제18권3호
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• pp.395-402
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• 2008

본 연구는 2007년 6윌부터 10월까지 제주도에서 양식장이 가장 많이 밀집되어 있는 제주도 동부 연안에 위치한 양식장 4개소를 대상으로 하여 사육 용수, 양어 사료, 양식 넙치의 미생물학적 오염도를 조사하였다. 식품병원성 미생물 중 일반세균과 총대장균군 그리고 Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus를 조사 하였다. 이번 연구를 수행하는 동안 동부지역은 집중적인 호우로 인해 전년보다 400 mm 이상의 많은 강우량을 나타내었다. 사육 용수의 검사결과 V. parahaemolyticus, Salmonella spp., S. aureus, B. cereus가 빈번하게 검출되었고, 양어 사료의 경우 Salmonella spp, S. aureus, B. cereus는 각각 $0{\sim}4.3{\times}l0^3$ CFU/ml, $0{\sim}2.7{\times}l0^4$ CFU/ml, $0{\sim}7.6{\times}l0^3$ CFU/ml 검출 되었다. 또한 양식 넙치의 미생물 검사 결과 적은 양이지만 Salmonella spp., S. aureus, B. cereus가 검출되었고, 총대장균군과 E. coli Ol57:H7은 검출되지 않았다. 이번 조사 결과로 보아 미생물학적 위해요소는 양식장의 작업 환경이나 주변 환경 등의 환경적 요인이 크게 작용하는 것으로 사료되며, 양식장의 위생관리에 작업자들은 주의를 기울여야 할 것으로 생각된다. 앞으로 이와 관련하여 수산물 위생에 대한 좀 더 체계적인 시스템을 도입하여 적용한다면 수산물에서 야기되는 문제점들이 해결되어 제주도의 청정 브랜드의 이미지를 더욱 부각시킬 수 있으며, 안전하고 깨끗한 수산물의 생산이 가능할 것으로 생각된다.

• Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.180-194
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• 2024

Mass mortalities of mud crab Scylla spp. larvae due to pathogenic Vibrio spp. outbreaks have frequently occurred in hatcheries. To overcome this problem, probiotics containing Bacillus subtilis bacteria are applied to inhibit pathogenic ones. We tested different doses of probiotic-containing B. subtilis (10⁸ CFU/g) on the Scylla tranquebarica larvae and investigated the microbiota population, including Vibrio. Water quality, larvae development, and crablet production were also monitored. The recently hatched larvae were grown in twelve conical fiber tanks filled with 200 L sterile seawater, with a salinity of 30 ppt at a stocking density of 80 ind/L. Four different doses of probiotics were applied in the larvae rearing, namely, A = 2.5 mg/L, B = 5 mg/L, C = 7.5 mg/L, and D = 0 mg/L, with three replicates. Next-generation sequencing analysis was used to obtain the abundance of microbes in the whole body of megalopa and the water media for larvae rearing after applying probiotics. Sixteen Raw Deoxyribonucleic Acid samples (eight from a whole body of megalopa extraction from four treatments of probiotics defined as A, B, C, D, and eight from water media extraction from four treatments of probiotic defined as E, F, G, H) were prepared. Then, they were sent to the Genetics Science Laboratory for NGS analysis. Ammonia, nitrite, total organic matter (TOM), larvae, and crablet production were monitored. Based on the Next-generation sequencing analysis data, the Vibrio spp. decreased significantly (p < 0.05) than control test (D) in megalopa-applied probiotics at the doses of 2.5 mg/L (A) and 7.5 mg/L (C) and in the water media for megalopa rearing treated with probiotics at the dosage of 5.0 mg/L (F). Ammonia in the zoea stage in B treatment and TOM in the zoea and megalopa stage in B and C treatments were decreased significantly (p < 0.05). It impacts the higher number of zoea survival in treatments B and C. Finally, it results in a significantly high crablet production in treatments B and C. Therefore, the dosage of 5 mg/L to 7.5 mg/L improves crablet S. tranquebarica production significantly.

• Fisheries and Aquatic Sciences
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• 제18권3호
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• pp.333-339
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• 2015

Red lip mullet Chelon haematocheilus (body weight = $468{\pm}91g$) which became sick during an outbreak of disease at mariculture facilities at Cheonsu Bay, Korea, during July-August 2013, were examined to identify the cause of the disease. Diseased mullets displayed green liver syndrome, and Lactococcus garvieae were isolated from their internal organs. Argulus sp., Trichodina sp., and/or Vibrio spp. were also discovered in some infected fish. Histopathological examination revealed that fatty liver syndrome with hepatocyte degeneration, reflected in heterokaryons, inflammatory lesions, and melanomacrophage centers ($MMC_S$), had caused fibrosis around the kidney, spleen, and blood vessels. After the outbreak, visceral fat and green liver syndrome in the mullets were consistently observed throughout the year in the same mariculture facilities, indicating that the cultured mullets suffered a chronic metabolic disorder. Although Vibrio spp. were also isolated from some individuals, L. garvieae, which is known to be a causative agent of red lip mullet mortality, was isolated from all diseased individuals. This is the first report of L. garvieae infection in cultured red lip mullet.

• 수산해양교육연구
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• 제28권6호
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• pp.1828-1833
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• 2016

The purpose of this research was to investigate the bacterial flora of healthy olive flounder larvae (Paralichthys olivaceus) and live feeds (Rotifer spp. and Artemia spp.). The total bacteria counts were $9.2{\times}10^7$ and $1.2{\times}10^{10}cfu/g$ and Vibrio sp.(82.8%) was dominant in rotifers. The total bacteria counts were $3.8{\times}10^6$ and $9.2{\times}10^6cfu/g$ and Vibrio sp.(73.3%) was dominant in artemia. In olive flounder larvae, the total bacteria counts were $1.4{\times}10^6{\sim}8.3{\times}10^7cfu/g$ and V. harveyi (38.5%) was dominant. It might be potential marker of disease outbreak in olive flounder larvae.

• 한국수산과학회지
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• 제52권5호
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• pp.539-546
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• 2019

The major cultured marine fishes in sea off the coast Gyeongsangnam-do Province, South Korea, were assessed and included 9.3% rockfish Sebastes schlegelii, 7.8% red seabream Pagrus major, and 2.1% rock bream Oplegnathus fasciatus. The number of insurance payments related to disease mortality in cultured fish in 2017 was fourfold that in 2016. Economic loss in aquaculture due to disease in cultured fish is high and represents an important inhibitory factor affecting marine fishery productivity. In 2018, diseases led to severe production losses in several aquaculture species: 40.0% in rockfish, 11.4% in olive flounder Paralichthys olivaceus, 10.0% in filefish Thamnaconus modestus, and 9.3% in red seabream. Fish-parasitic pathogens such as Microcotyle sebastis, Alella spp., and Dactylogyrus spp. enter mainly via the gills and skin surface. Among bacterial pathogens, Vibrio species were most common, with Vibrio harveyi being the dominant species causing infections in these fishes. The bacterium Lactococcus garvieae is thought to exhibit host specificity in fish. The fish species in the present study exhibited a higher tendency for infection by heterologous pathogens than by a single pathogen; therefore, it is necessary to devise new strategies for treating diseases in cultured fish.

• 한국식품위생안전성학회지
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• 제27권3호
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• pp.290-294
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• 2012

Vibrio spp. and Streptococcus spp. have caused a considerable disease of farmed fish and economic loss in fish farming and seafood industry. In this study, the efficacy of an aquatic disinfectant tablet composed to calcium hypochlorite was evaluated against V. anguillarum and S. iniae. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. An aquatic disinfectant tablet and test bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OM) according to treatment condition. V. anguillarum on the DW, HW and OM condition was completely inactivated with 16,000 15,000 and 13,000 fold dilutions of the disinfectant, respectively. On the DW, HW and OM condition, S. iniae was absolutely inactivated with 17,000 16,000 and 14,000 fold dilutions of the disinfectant, respectively. As an aquatic disinfectant tablet possesses bactericidal efficacy against fish pathogenic bacteria such as V. anguillarum and S. iniae this disinfectant solution can be used to control the spread of fish infective bacterial diseases.

• 한국수산과학회지
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• 제37권2호
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• pp.91-97
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• 2004

Applications of probiotics to shrimp ponds were carried out to determine their effects on water quality. Fermented solutions consisting of Bacillus spp. and Nitrosomonas spp. were applied to a 4 ha shrimp (Fenneropenaeus chinensis) pond from July to September, 2000. In the pond treated with probiotics, daily variations of DO and pH, and concentrations of DIN and DIP were lower than those in the ponds without probiotic treatment. Concentration of phytoplankton was less variable and the number of species was more variable in the probiotic-treated pond than those in the control pond. Variation of bacterial numbers and the number of Vibrio spp. were lower in the treated pond than those in the control pond. It is confirmed that the probiotics can be used to improve water quality of the shrimp ponds.

• 대한의생명과학회지
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• 제13권1호
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• pp.71-73
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• 2007

For the rapid detection of objective pathogenic bacteria from colon biopsy specimens, multiplex PCR (polymerase chain reaction) method was developed. The major objective bacteria in this study were Shiga-like toxin producing E. coli O157:H7, Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, Shigella spp. Salmonella spp. and Yersinia spp.. To detect simultaneously 7 kinds of pathogenic bacteria in single reaction tube, multiplex PCR system was executed using 6 sets of primers used in single PCR system for the respective bacteria. The results in this research might be applied for the detection of pathogenic bacteria form colon biopsy samples.

• 한국어병학회지
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• 제35권1호
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• pp.135-140
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• 2022

In this study, we determined the cause of a disease outbreak in small yellow croaker(Larimichthys polyactis) in Jeju island. The major external signs in the dead fish were hemorrhage of the skin. Vibrio harveyi were isolated from a few fishes and viruses were not detected from the diseased fish. However, flukes were confirmed on the skin and we conducted molecular identification and phylogenetic analysis of the isolated parasites. The obtained 28S rRNA sequence of our specimen(Accession No. OM333244) showed the highest homology with Neobenedenia girellae, while the COI sequence of our specimen showed the highest homology with N. melleni. Further sequence analysis with other genes and morphological observation are necessary for accurate identification.