• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.6
• /
• pp.826-832
• /
• 2023

Clostridium perfringens causes diarrhea and other diseases in humans and animals. We investigated the prevalence, toxin gene profiles, and antimicrobial resistance of C. perfringens isolated from commercial jeotgal sample. C. perfringens was isolated from 11 of 22 commercial jeotgals. All C. perfringens strains were positive for the alpha toxin gene, but not for the beta, epsilon, iota, CPE or NetB toxin genes; therefore, all strains were identified as type A C. perfringens. However, the beta2 toxin gene was identified in 54.5% of isolates. Disk diffusion susceptibility tests showed that most isolates were resistant to kanamycin (90.9%), nalidixic acid (72.7%), oxacillin (54.5%), erythromycin (27.3%), ciprofloxacin (9.1%) and clindamycin (9.1%). However, all strains were susceptible to 14 other antimicrobial including amoxicillin, ampicillin, and chloramphenicol. The average minimum inhibitory concentrations against C. perfringens of clindamycin, kanamycin, and nalidixic acid were 128.0, 128.0, and 54.0 ㎍/mL, respectively. These results provide new insight into the necessity for sanitation of commercial jeotgal, and provide evidence to help reduce the risk of contamination with antimicrobial-resistant bacteria.

• Korean Journal of Ecology and Environment
• /
• v.36 no.3 s.104
• /
• pp.369-374
• /
• 2003

Nonylphenol (NP), an well known aquatic contaminant, has been known to induce abnormalities in various aquatic animals. In an effort to develop proteome in the study of aquatic contamination of NP and its impact on the amphibia, protein changes in liver tissues of Korean red bellied frog, Bombina orientalis was investigated following the NP exposure. NP was administered intraperitoneally to male B. orientalis at 10 mg/kg body weight. At 48 and 96h after the treatment, the frog livers were sampled, and the protein fraction was separated using two dimensional gel electrophoresis (2D/E) and visualized with Coomassie brilluant blue staining. The 2D/E Images of the tissue from the animals treated with NP showed marked changes of protein spots (about 20% of total protein spots). Analysis of the 50-60 separated spots allowed identification of the major protein changes in the overall pattern for the stressor (NP) by time (0,48 and 96 h). At 48h after treatment, 8 spots were increased and 12 spots were reduced. Then, at 96h after treatment, 10 spots were increased and 8 spots were reduced. In total, approximately 29% of liver proteins showed the altered expression following the NP treatment. It is suggested that protein expression was repressed by blocking of certain metabolisms at 48 hand induced by the synthesis of new proteins for adaptation at 96 h following NP exposure. This application for 2D/E analysis may show promise in searching biomarkers for environmental proteomics in amphibians.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.4
• /
• pp.413-420
• /
• 2017

The increase in the number of mud shrimps Upogebia major is a concern because of their negative effects on shellfish aquaculture, including Manila clam Venerupis philippinatum along the west coast of Korea. This study developed a behavioral analysis system for aquatic animals using a set of monochromatic light-emitting diode (LED) modules covering the visible light range at similar intervals. Movements of mud shrimp were monitored using a tracking system under illumination with infra-red light and an LED of 660 nm wavelength without provoking stimulation. The minimum light intensity needed to induce a photoresponse by the mud shrimp was $10{\mu}mole/m^2/s$ under the conditions tested. Of the six kinds of LED illuminations tested, the most sensitive response was obtained with illumination with the 505 nm LED, followed in order by LEDs with peak wavelengths of $525nm{\fallingdotseq}465nm$ > $405nm{\fallingdotseq}590nm$ > 660 nm. These findings should help to identify LED sources that efficiently induce movement of the mud shrimp and also for monitoring movement without stimulating.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2004.06a
• /
• pp.173-177
• /
• 2004

The acute toxicities of two major anti-pathogenic veterinary medicines, i.e., ciprofloxacin and enrofloxacin, and six benzimidazole anthelmintics, i.e., albendazole, thiabendazole, flubendazole, febantel, fenbendazole, and oxfendazole, were evaluated with a marine bacterium, Vibrio fischeri, and invertebrate Daphnia magna. These veterinary medical products have been widely used for farm animals, but their impact on aquatic fauna has seldom been investigated. In general, daphnids responded as much as 3 orders of magnitude more sensitively to the tested pharmaceuticals than the microbes. For Daphnia, the most toxic product among the tested anthelmintics was fenbendazole, followed by flubendazole > albendazole ${\approx}$ febantel > thiabendazole > oxfendazole. Daphnids' EC50 values obtained from 48 to 96 hrs of fenbendazole exposure ranged from 2.7 to 6.3 ug/L. The mixture toxicity of the test pharmaceuticals was generally additive in nature and was well predicted by a concentration addition model. Using the predicted no effect concentrations (PNECs) of the benzimidazole derivatives estimated from this study, and predicted environmental concentrations (PECs) of these pharmaceuticals, the risk quotients of each anthelmintics were calculated. Most of the test anthelmintic compounds resulted in risk quotients greater than 1. Especially, risk quotient for fenbendazole was 2,791, which strongly indicates this compound might cause severe ecological consequences, should no future action be taken. This study is the first report on the aquatic toxicities and potential ecological risk of major anthelmintic and antimicrobial veterinary products in Korea. The result of this study provides information necessary for conducting more detailed ecological risk assessment of pharmaceutical products in ambient water and guiding proper management decision.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.1
• /
• pp.116-123
• /
• 2023

Flow-through aquaculture systems generate large amounts of wastewater containing compounds such as solids that can settle near aquafarms and cause eutrophication. The settled solids are often reintroduced into flow-through systems, and aquatic animals can be affected by the solids and pathogens associated with these solids. For a sustainable aquaculture operation, adequate wastewater treatment is required. Hydrocyclones are one of the most promising technologies for the removal of solids in aquaculture wastewater. In this study, a model for performance prediction of hydrocyclones was investigated under three different operating conditions: water temperature, solids concentration, and water inlet velocity. The synthetic solids solution was prepared using settled solids from abalone aquaculture farms. The daily solids removal rates of the tested hydrocyclones ranged from 0.18 to 26.0 g solids-m^-3-day^-1, and removal efficiency ranged from 5.1 to 34.4%. The inlet water velocity had the greatest effect on solids removal and hydrocyclone efficiencies. The following multiregression model equation was derived from the daily solids removal rate (g solids-m^-3-day^-1) results for water temperature (T, ℃), solids concentration (SS, mg-L^-1), and tangential inlet water velocity (TIV, m-sec^-1): daily solids removal rate: f(z)=4.465+0.809TIV-0.375T+0.217SS (r²=0.976).

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.2
• /
• pp.297-305
• /
• 2003

The family of lemnacae colloquially known as duckweed contains the world' smallest species of flowering plants (macrophytes). Aquatic and free-floating, their most striking qualities are a capacity for explosive reproduction and an almost complete lack of fibrous material. They are widely used for reducing chemical loading in facultative sewage lagoons, but their greatest potential lies in their ability to produce large quantities of protein rich biomass, suitable for feeding to a wide range of animals, including fish, poultry and cattle. Despite these qualities there are numerous impediments to these plants being incorporated into western farming systems. Large genetically determined variations in growth in response to nutrients and climate, apparent anti-nutritional factors, concerns about sequestration of heavy metals and possible transference of pathogens raise questions about the safety and usefulness of these plants. A clear understanding of how to address and overcome these impediments needs to be developed before duckweed is widely accepted for nutrient reclamation and as a source of animal feed.

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2003.10a
• /
• pp.155-156
• /
• 2003

The Coleoptera is one of the most species-rich order of animals, adapted to most terrestrial and freshwater aquatic habitats. Among them, the mulberry longicom beetle, Apriona germari Hope, is widely distributed in eastern Asia and became one of the major pests of mulberry tree in Korea. To obtain genetic information on the mulberry longicorm beetle, we have constructed cDNA library from the larvae whole-body. Here, we report Apriona germari ESTs profiles determined the 5'most end of 3072 clones. (omitted)

• The Journal of Fisheries Business Administration
• /
• v.40 no.3
• /
• pp.29-49
• /
• 2009

There are various types of predictable economic benefits to restoring beneficial uses from contaminated marine sediment cleanup. These benefits can be derived from reduction in aquatic animals died or infected, increase in their consumption recovery, increase in tourism including recreational fishing, reduction in human health risk, increase in amenity and aesthetics, increase in ecosystem integrity, and so on. The paper focuses on estimating the net increase in value for producers and consumers from producing and consuming those fish due to the pollution reduction of marine contaminated cleanup project. Almost Ideal Demand System(AIDS) is employed for estimate of the demand for fish, and the production cost function for fish are determined using market data. The result shows 10.8 billion won per year for economic surplus to the net increase for producers and consumers.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.16 no.4
• /
• pp.115-124
• /
• 2013

This study was conducted to make a biotop planning and construct 3 types of biotop by each site conditions. Three sites of different types in ecological and scenery conservation area of the Dong-gang river were selected by expert brain-storming process and constructed terrestrial biotops and aquatic biotops. Targets of 3 sites were set up such as constructing a habitat for Kaloula borealis and an ecological education place, building a terrestrial biotopes and monitoring the natural vegetation succession, and constructing a habitat for Luciola unmunsana Doi. The study results can be applied hereafter to ecological restoration projects, after construction of habitat, the priority should be prepare measures of monitoring and maintenance, hereafter continuous study on ecological restoration should be performed actively through construction of biotope and wild animals and plants habitat.

• Korean Journal of Veterinary Research
• /
• v.49 no.1
• /
• pp.35-38
• /
• 2009

The zebra shark Stegostoma fasciatum which had been reared in the commercial aquaria was found dead and submitted for postmortem examination. A pure bacterial culture was isolated from pale and enlarged liver. The analysis of ureC and 16S rRNA genes confirmed the isolate as Photobacterium (P.) damselae subsp. damselae and this pathogen was sensitive to gentamicin. Although, no mortality in mouse was observed in the experimental infection study, the isolation of this pathogen in aquarium fish is significant because it can act as a reservoir to other aquatic animals and can also be zoonotic potential to human during aquarium management. This paper describes the first isolation of P. damselae subsp. damselae from zebra shark.