• Journal of fish pathology
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• v.13 no.2
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• pp.143-146
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• 2000

The effectiveness of bronopol and bithionol in treating Ichthyobodo sp. infestation in cultured olive flounder was investigated, and compared them with formalin. Bath with formalin at 200 ppm or bithionol at 100 ppm for 1 h showed complete removal of Ichthyobodo sp. from all the experimental fish. Baths with lower concentrations of formalin (50 and 100 ppm) or bithionol (25 and 50 ppm) significantly reduced infection intensities of Ichthyobodo sp. On the other hand, baths with bronopol or intubation of bithionol at various concentrations were not effective against Ichthyobodo sp. infestation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.34-40
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• 2009

In fresh water fish hatcheries and farms, Saprolegniales often cause serious mortality to the fish and their eggs. Malachite green is an effective antifungal agent, but is carcinogenic to fish and humans. Alternative antifungal agents are needed. Presently, we tested various concentrations of MBT-01108 (Opuntia ficus-indica extracts) alone and in combination with bronopol, formalin and sodium chloride (MBT-01108 mixture) on in vitro mycelial growth and in vivo remediation of adult eel, Anguilla japonica, infected with Saprolegnia sp. and fertilized eggs of chum salmon, Oncorhynchus keta, to evaluate the compounds' antifungal efficacy on eyed-egg and hatching rates. MBT-Oll08 mixtures incorporating bronopol and formalin at respective concentrations of 50 and 30 parts per million (ppm), and 100 and 20 ppm were most effective in controlling Saprolegnia in vitro and in vivo (P<0.05). Repeated daily exposures to 50 ppm and 100 ppm MBT-01108 were more effective than exposure every 2-3 days post-fertilization for the inhibition of Saprolegnia infection of rainbow trout, Oncorhynchus mykiss eggs as compared with control (0 ppm).

• Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.1.1-1.6
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• 2016

Although soft tunic syndrome (STS) in the ascidian is a serious disease, helpful measures have yet not been established. It was examined in this study by applying aniti-parasitic drugs to eradicate the causative protozoa Azumiobodo hoyamushi from infected ascidians. Formalin was synergistic in killing parasites in vitro when co-treated with hydrogen peroxide ($H_2O_2$) or bronopol, but not with chloramine-T or povidone-iodine (PVP-I), when tested with in vitro parasite culture. The synergistic effects did not change when $formalin-H_2O_2$ (or bronopol) ratios were changed. It was found that treatment periods less than 60 min achieved a sub-maximal efficacy. Increasing drug concentration while keeping 30 min period improved anti-parasitic effects. Anti-parasitic effects of $formalin(F)+H_2O_2$(H) were also assessed in an in vivo STS model infected with cultured parasites. It was observed that combined 50 (40F + 10H) and 100 (80F +20H) ppm were effective in partially preventing STS-caused mortality. In horizontally transmitted artificial STS model, significant prevention of ascidian mortality was also observed after 50 ppm. Marked reduction of living parasites were noted after drug treatments in vivo. The results provide a highly useful basis to develop a preventive or treatment measure against the currently uncontrollable STS in the ascidian.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.11 no.1
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• pp.1-12
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• 1985

A strain of Pseudomonas aeruginosa was isolated from the spoiled product and its characteristics on various formaldehyde-releasing preservatives were investigated. This strain, P. aeruginosa FR, could utilize 1.0% of imidazolidinyl urea and 0.2% of DMDM hydantoin as a sole carbon and nitrogen source in the minimal salts medium. With the growth of the strain in minimal salts medium containing imidazolidinyl urea, formic acid was initially accumulated according to the decrease of formaldehyde concentration. It was suggested that formaldehyde dehydrogenase was involved in this oxidation process and could catalyze formaldehyde, imidazolidinyl urea, DMDM hydantoin and quaternium-15, but not bronopol. MICs of this strain to each preservation were 0.03% in formaldehyde, 1.0% in imidazolidinyl urea, 0.2% in DMDM hydantoin, 0.2% in quaternium-15 and 0.1% of EDTA-2Na. But the MICs were diminished about ten times when 0.01% of EDTA-2Na was added to the preservative systems. In actual challenge test, the eyeliner and the pack which contained paraben and imidazolidinyl urea were not able to be protected from this strain, but when 0.05% EDTA-2Na was added the products were sufficiently preserved.

• Journal of fish pathology
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• v.20 no.2
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• pp.147-160
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• 2007

Four strains of water mold, ChS-E0511, RaT-E0511, RaT-A0512 and MaS-F0512, were isolated from salmonid fish and/or their eggs taken from culture farms in Yangyang, Milyang and Pyeongchang, Korea in 2005. Descriptions of their morphological aspects, the results of the phylogenetic analysis conducted, and the sequence of the small sub-unit 18S rRNAs of the isolates confirmed that they all belong to the species Saprolegnia parasitica. Only one species, ChS-E0511, which was isolated from fertilized eggs of the chum salmon, was classified as part of the S. parasiticaGroup 1 according to its oogonia and gemmae production. The chemotherapeutic effects of various chemicals on the ChS-E0511 strain were assessed from the inhibitory effects of growth in GY media and the relative ratio of eyed eggs to fertilized eggs of the rainbow trout. Malchite green, a prohibited substance in food animals, was better than others, such as the Opuntia ficus-indicaextract, 2-bronopol, and sodium chloride. These results suggest that the fungi isolated from salmonids and/or their eggs identified as S. parasitica were composed of more than two groups. These isolates will be useful in an intensive evaluation of therapeutic agents.

• Journal of fish pathology
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• v.26 no.1
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• pp.31-38
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• 2013

The edible ascidian, Halocynthia roretzi is a commercially important fisheries resource in Korea. However, there have been outbreaks of mass mortality due to soft tunic syndrome. It was discovered recently that the cause of death is infection by a protozoan parasite Azumiobodo hoyamushi. Alamar blue assay and microscopic counting were used to estimate anti-protozoal effects of 20 drugs having different action mechanisms. Through comparison of alamar blue assay and microscopic counting, 6 drugs were found to be potential in protozoan-killing effects: amphotericin B, formalin, hydrogen peroxide, bithionol, benzalkonium chloride, bronopol (24hr-$EC_{50}{\leq}20{\mu}g/ml$). The preliminary data can be used as a basis to develop anti-protozoal agents against A. hoyamushi.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.32-37
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• 2003

Bacterial soft rot by Erwinia carotovora subsp. carotovora is one of the diseases causing the biggest problem in Chinese cabbage. Chemical screening was conducted to select effective agents for controlling bacterial soft rot. Control effect of antibiotics, plant activator, and Biokeeper (avirulent Erwinia) to soft rot were tested by in vitro assay, nursery test, and field experiment. The in vitro assay was done by paper disc method and potato slice method. The nursery test was performed by using mineral oil inoculation method with consistent disease induction. The in vitro assay showed that streptomycin, oxolinic acid, bronopol, and copper hydroxide significantly suppressed the growth of pathogenic bacterium and the decomposition of potato slice. However, plant activators including acibenzolar-S-methyl did not show the suppressive effect on the growth of pathogenic bacterium and the decomposition of potato slice. When applied by the nursery test condition using mineral oil inoculation method with Chinese cabbage 'Kangruckyeurum', Biokeeper, oxolinic acid, antibiotics streptomycin, validamycin, and copper compound provided 83.5%, 95.2%, 91.2%, 57.5% and 79.9% in control efficacy, respectively. However, the control effect of acibenzolar-S-methyl showed to be low to cause phytotoxicity. Also acibenzolar-S-methyl showed a significant control effect in the field experiment with Chinese cabbage 'Sanchon' in 2000, but the field experiment with Chinese cabbage 'Kangruckyeurum' in 2001 revealed it had phytotoxicity to Chinese cabbage. Such a difference was considered to be caused by differences in phytotoxic reaction of Chinese cabbage cultivars to the chemical. Streptomycin+copper, copper hydroxide and Biokeeper showed 79.7%, 71.9% and 60.9% in control efficacy, respectively, in the field experiment with Chinese cabbage 'Sanchon' in 2002.