• 한국환경과학회지
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• 제9권5호
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• pp.365-368
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• 2000

The antibacterial effect amino acid-copper(II) surfactant on fish pathogens was studied. Fish pathogens of Edwardsiella tarda Vibrio anguillarum Aeromonas hydrophila and Streptococcus sp. were selected cultured in nutrient agar and adjusted at $2{\times}10^5~10^6 CFU/$m\ell$$ in phosphate buffer saline before the addtion of amino acid-copper(II) surfactant with different concentrations. All tested pathogens died within 1 hour with 1 ppm of amino acid-copper(II) surfactant. In comparison with formalin and ET. amino acid-copper (II) surfactnat was more effective in antibacterial capacity.

• 대한수의학회지
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• 제37권1호
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• pp.203-212
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• 1997

Antibacterial efficacy and safety of copper sulfate pentahydrate (5% solution) was evaluated in laboratory and field studies for disinfection of some fish bacterial pathogens in cultured fish, flounder(Paralichthys olivaceus), mirror carp(Cyprinus carpio), gold fish(Carrassius auratus) and eel(Anguilla japonica). Dipping of fishes for acute toxicity was performed for a period of 48h, and the TLm value(median tolerance limit) were 4.0ppm in mirror carp and flounder, 4.4ppm in rainbow trout, and 10.0ppm in gold fish. After exposure below than TLm value for 1 month, no side effects and histopathological changes were observed. The test drug were shown high antibacterial activities against most bacterial pathogens by exposure in the laboratory and field trials. However, Aeromonas salmonicida showed a resistance to the dosage. We can prevent outbreaks of bacterial diseases of fish by the dosage of 1ppm for 6hr and the test drug is thought to be used effectively and widely as a disinfectant against most bacterial fish pathogens.

• Fisheries and Aquatic Sciences
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• 제19권6호
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• pp.28.1-28.7
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• 2016

Background: Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm) on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results: We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and $68.4J\;cm^{-2}$, respectively, produced one log reduction in the bacterial populations), whereas Streptococcus parauberis was the least susceptible ($153.8J\;cm^{-2}$ per one log reduction). In general, optical density (OD) values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions: This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.

• 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.

• 한국어병학회지
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• 제33권1호
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• pp.91-95
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• 2020

Fish bacterial diseases have spread and caused serious problem for cultured marine fish in Korea. The important bacterial disease affecting mariculture such as olive flounder (Paralichthys olivaceus) are caused by Edwardsiella tarda, Vibrio scophthalmi and Streptococcus parauberis. For the bacterial disease protection in aquaculture industry, the water treatment is needed in aquaculture system. During the last decades atmospheric pressure non-thermal plasma in contact with liquids have received a lot of attention of environmental and medical application. In this study, we determined the disinfectant effect in seawater and three major fish bacterial disease pathogens by using low frequency plasma treatment. Three fish bacteria (E. tarda, V. schophthalmi, S. parauberis) were not detected within 16 min, 150 min and 270 min of 20 L, 500 L and 1 ton seawater post low frequency plasma treatment, respectively. Three major fish bacterial disease pathogens were not detected within 2 min after the low frequency plasma treatment, suggesting that the low frequency plasma possess disinfectant effectiveness.

• 한국어병학회지
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• 제22권1호
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• pp.75-83
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• 2009

우리나라 연안에서 채포되는 자연산 어류를 대상으로 주요 어류 병원체의 검출 유무를 조사하기 위해 2008년 2월부터 10월까지 질병 조사를 실시하였다. 포항, 거제, 여수 및 제주 지역의 정치망, 양망에 채포된 어류 및 공동어시장에서 판매되는 어류를 구매하여 총 401마리를 실험에 사용하였다. 전체 조사 시료 중 152마리에서 17종의 병원체가 분리되었다. 기생충, 세균 및 바이러스의 검출률은 각각 21.4%, 17.0% 및 2.7%로 나타났다. 분리된 기생충류는 Scutica, Trichodina, Cryptocaryon, Dactylogyrus, Microcotyle, Benedenia, Bivagina, Heteraxin, Caligus, Epistylis 및 nematode 이며, 세균류로는 Vibrio, Streptococcus, Photobacterium, Psuedomonas가 우점적으로 분리되었고 바이러스는 조사대상인 6종중에서 red sea bream iridovirus (RSIV) 및 lymphocystis disease virus(LDV)가 검출되었다. 과(科)별로 검사시료가 30개체 이상인 어류 중에서 양볼락과, 쥐치과, 가자미과, 도미과 및 전갱이과의 검출률이 59.2%, 48.4%, 34.2%, 30.6% 및 18.2%로 나타났다.

• 한국어병학회지
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• 제35권2호
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• pp.205-214
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• 2022

In recent years, there have been many studies investigating changes in animal behavior using video tracking technology to track motion. However, there have been very few studies and results on changes in the behavior of fish infected with a pathogen. Therefore, the present study attempted to analyze the behavior of angelfish (Pterophyllum scalare) infected with bacterial pathogens using video tracking. Two cameras were placed in front of the water tank to obtain behavior data, and tracking was performed for three days until the day of death. Data such as average speed, changes in speed, the locations of the fish in the tank, and fractal dimension were statistically analyzed based on the fish speed and location in the tank of the fish. For bacterial infection, an individual angelfish was intraperitoneally injected with approximately 10⁶ CFU ml^-1 of Aeromonas hydrophila or Edwardsiella piscicida. The experiment was carried out five times for each group. Fish infected with the bacterial pathogens showed a tendency to increase in speed and to spend more time in the upper part of the tank one or two days before death. On the day the fish died, the average speed, changes in speed, and the fractal dimension value were significantly lower than the corresponding values in the control group, and the fish also remained in the lower part of the tank. Our results indicated that behavioral changes in fish could be successfully detected earlier than death using video tracking technology, and that this method presents potential for disease monitoring in aquaculture.

• Journal of the Korean Wood Science and Technology
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• 제48권4호
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• pp.527-547
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• 2020

어병 세균은 어류 양식업의 경제적 피해 뿐만 아니라, 인수공통감염원으로 알려진 전염성 병원균이다. 어병 세균을 제어하기 위해 지속적인 항생제의 사용은 부작용이 수반되기 때문에, 천연 유래 소재의 개발이 요구된다. 본 연구에서는 항생제대체제 개발을 위해 항세균효과가 우수한 침엽수 정유를 발굴하고자 하였다. 소나무과에 속하는 전나무 (Abies holophylla), 곰솔 (Pinus thunbergii), 섬잣나무 (Pinus parviflora), 솔송 (Tsuga sieboldii), 리기테다소나무 (Pinus rigitaeda)의 잎에서 hydro-distillation법을 이용하여 정유를 추출하였으며, 추출된 정유는 어병 세균인 Edwardsiella tarda, Photobacterium damselae, Streptococcus parauberis, Lactococcus garivieae에 대하여 항균력을 평가하였다. 그 결과, 전나무와 곰솔 잎 정유가 그람 음성 세균인 E. tarda와 P. damselae에 대하여 선택적으로 강한 항균력을 나타냈다. GC-MS 분석 결과, 전나무 잎 정유의 주요 성분은 (-)-bornyl acetate (29.45%), D-limonene (20.47%), camphene (11.73%)이고, 곰솔 잎 정유의 주요 성분은 α-pinene (59.81%)으로 각각 확인되었다. 또한, 미량으로 존재하지만 정유와 동일한 효능을 나타내는 유효 성분으로 oxygenated monoterpenes인 neryl acetate, (-)-borneol, (-)-carveol의 세가지 화합물을 구명하였다. 따라서 그람 음성어병세균의 생장억제효과가 우수한 전나무와 곰솔 잎 정유는 사료 첨가제, 수산용 의약품 등 생물학적 제제로 활용 될 수 있을 것으로 사료된다.

• Natural Product Sciences
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• 제19권1호
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• pp.61-65
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• 2013

A bioassay-guided fractionation of the extract of the fungus Paecilomyces variotii, which was derived from the giant jellyfish Nemopilema nomurai, led to the isolation of antibacterial compounds viriditoxin and its monomeric subunit semi-viriditoxin. Viriditoxin showed significant antibacterial activity against several marine fish and human pathogens including MDR strains. Significant potencies against resistant pathogens such as VRE Enterococcus faecium, VRE Enterococcus faecalis, and MRSA were highly interesting. Viriditoxin also showed notable antibacterial activity against the fish pathogen Streptococcus iniae. Its potency was over 100-fold higher than oxytetracycline which is employed as a general antibiotic for aquaculture.

• Fisheries and Aquatic Sciences
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• 제22권2호
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• pp.5.1-5.9
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• 2019

Background: Live fish import may lead to the unintended introduction of pathogens. We examined the monthly distribution of microbial pathogens in ornamental finfish imported into South Korea over a 6-month period. Results: Vibrio alginolyticus was detected in one lemon damsel in June and July; V. vulnificus was detected in one lemon damsel, one caerulean damsel, and one pearl-spot chromis and one ocellaris clownfish in July, April, and May, respectively; Photobacterium damselae was detected in one ocellaris clownfish and one caerulean damsel in June and July, respectively; V. anguillarum was detected in one pearl-spot chromis in February; V. harveyi was detected in one ocellaris clownfish and two mandarin fish in February and April, respectively; Yersinia ruckeri was detected in a pearlscale goldfish group in June and July and in two colored carp groups in July; and Lactococcus garvieae was detected in a lemon damsel group and a sutchi catfish group in July and May, respectively. European catfish virus, the only viral pathogen detected, was found in two sutchi catfish groups in May. Conclusion: This study is the first to identify pathogenic species and the presence or absence of pathogens (non-quarantine diseases) in imported ornamental finfish. These results demonstrate that various pathogens with the potential to harm indigenous fish populations can accompany ornamental finfish imported into South Korea.