• Journal of Fisheries and Marine Sciences Education
• /
• v.29 no.2
• /
• pp.581-585
• /
• 2017

To strengthen the quality control of aquatic drugs, we compared the internal and external(EU, USA and Japan) aquatic drug classification systems and proposed a new aquatic drug classification system. Aquatic drugs are classified on the basis of their functional the functional characteristics or safety management degree of aquatic drugs. We suggested that the aquatic drugs can be categorized into 7 levels according to their functional characteristics and classified into 3 levels according to the safety management degree of aquatic drugs.

• Journal of fish pathology
• /
• v.27 no.1
• /
• pp.67-75
• /
• 2014

Aquaculture drugs have used to prevent disease in aquaculture field for many years. In spite of many advantages, overdose and abuse may cause environmental pollutions and antibiotic resistances. Many countries try to protect the environment, biospecies and food safety. Recently, Korea enact laws and ordinances such as the Aquatic Animal Disease Control Act. The purpose of this act to contribute to the stable production and control system for aquatic diseases. The Maximum residue limits (MRLs) of aquaculture drugs have been established by Ministry of Food and Drug Safety (MFDS) and Drug licensing was in National Fisheries Research and Development Institute (NFRDI) by Aquatic Animal Disease Control Act. There is 750 items in aquaculture drugs and these are classified into 4 group, which is approval, necessary for prescription, unregulated and safety drug, and banned drug. MRLs of 30 items in aquaculture drug have been established by Food Sanitation Act. Future research is required to determine the suitable for abundant varied fishes of drugs for side effects and safety.

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

• Fisheries and Aquatic Sciences
• /
• v.22 no.12
• /
• pp.29.1-29.7
• /
• 2019

Veterinary drugs are widely used to protect production-related diseases and promote the growth of farmed fish. The use of large amounts of veterinary drugs may have potential risk and cause adverse effects on both humans and the environment. In this study, we developed risk-based ranking based on a scoring system to be applied in the national residue program. In this approach, the following three factors of veterinary drugs that may occur as residues in fishery products were considered: potency (acceptable daily intake), usage (number of dose and withdrawal period), and residue occurrence. The overall ranking score was calculated using the following equation: potency × usage (sum of the number of sales and withdrawal period) × residue occurrence. The veterinary drugs that were assigned high score by applying this approach were enrofloxacin, amoxicillin, oxolinic acid, erythromycin, and trimethoprim. The risk-based approach for monitoring veterinary drugs can provide a reliable inspection priority in fishery products. The developed ranking system can be applied in web-based systems and residuemonitoring programs and to ensure safe management of fishery products in Korea.

• Journal of fish pathology
• /
• v.5 no.2
• /
• pp.77-85
• /
• 1992

This study was carried out in order to investigate the immunosuppressive factor and immune response of color carp. The protection and serum antibody production of juvenile color carp aganist Aeromonas hydrophila were investigated on the effect of temperature differences and injected several aquatic drugs, i.e. Hydrocortisone, Oxytetracycline, Chloramphenicol and Ascorbic acid. The fish were injected intraperitoneally with 1mg/fish of HKC and FKC at three different temperature conditions as $16^{\circ}C$, $24^{\circ}C$, and $32^{\circ}C$ respectively. There were induced better protection and serum antibody production in the fish which had been kept at $24^{\circ}C$ than in the fish which had been kept at $16^{\circ}C$ and $32^{\circ}C$. The FKC immunized fish were followed 24 hrs later with intraperitoneal injection of 40mg/kg body weight of Hydrocortisone, 60mg/kg body weight of Oxytetracycline. 60mg/kg body weight of Chloramphenicol and 30mg/kg body weight of Ascorbic acid, respectively. The control fish were injected PBS only. The fish given the above aquatic drugs reduced serum antibody production level and protection rate when compared to control fish. As the results, immune response of juvenile color carp immunized FKC at $24^{\circ}C$ was more effective than $16^{\circ}C$ or $32^{\circ}C$ and immune response of juvenile color carp injected several aquatic drugs which was seemed to be immunosuppressive factor.

• Fisheries and Aquatic Sciences
• /
• v.19 no.10
• /
• pp.45.1-45.5
• /
• 2016

As a novel strategy to remove ${\beta}$-lactam antibiotic residues from fish tissues, utilization of ${\beta}$-lactamase, enzyme that normally degrades ${\beta}$-lactam structure-containing drugs, was explored. The enzyme (TEM-52) selectively degraded ${\beta}$-lactam antibiotics but was completely inactive against tetracycline-, quinolone-, macrolide-, or aminoglycoside-structured antibacterials. After simultaneous administration of the enzyme with cefazolin (a ${\beta}$-lactam antibiotic) to the carp, significantly lowered tissue cefazolin levels were observed. It was confirmed that the enzyme successfully reached the general circulation after intraperitoneal administration, as the carp serum obtained after enzyme injection could also degrade cefazolin ex vivo. These results suggest that antibiotics-degrading enzymes can be good candidates for antibiotic residue depuration.

• Fisheries and Aquatic Sciences
• /
• v.23 no.4
• /
• pp.10.1-10.10
• /
• 2020

Background: Butaphosphan (BTP) has recently been introduced into the Korean aquaculture sector as a stressattenuating agent. In this study, a sensitive chemical analytical method was established for the detection of BTP in the olive flounder (Paralichthys olivaceus) tissues. Methods: Utilizing a method employing liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), detection sensitivity, specificity, and precision were satisfactorily established. Temporal changes in the BTP plasma and muscle concentrations were assessed after a single intramuscular injection of BTP (50 and 150 mg/kg) to the olive flounder maintained at 13 ℃ or 22 ℃. Results: High BTP plasma levels were achieved immediately after the injection, and the drug was rapidly eliminated. Additionally, plasma BTP levels were markedly dependent on the elimination rate, which, in turn, seemed dependent on the water temperature, with the drug elimination half-life and mean residence time significantly shorter at 22 ℃ than 13 ℃. Overall, muscle BTP levels were markedly lower than the plasma levels. Notably, muscle levels were not influenced by water temperatures. Muscle BTP concentrations were used to estimate the necessary withdrawal period for drugs used in food fish, with BTP levels maintained far below the possible hazardous limit. Conclusions: In conclusion, the established LC-MS/MS method can be used for BTP residue detection with high sensitivity and reproducibility.

• Journal of fish pathology
• /
• v.31 no.1
• /
• pp.15-21
• /
• 2018

Differences in in vivo virulence and in sensitivity to drugs among different isolates of Miamiensis avidus were analyzed. The isolate III showed the highest resistance against the scuticocidal activity of olive flounder (Paralichthys olivaceus) serum, and induced the highest mortalities of olive flounder fingerlings. The isolate II showed significantly higher serum resistance than the isolate I, but in vivo virulence of isolate II was not significantly different from that of isolate I. The secreted proteinases activity of isolate III was significantly higher than that of isolate I and II, and the activity was significantly reduced by the addition of E-64, a cysteine proteinases inhibitor. There were no differences among isolates in the sensitivity to doxycycline, however, there were significant differences in sensitivities to mebendazole and bithionol. These results suggest that the different characteristics of different M. avidus isolates should be taken into consideration for the development of control measures against scuticociliatosis.

• Korean Journal of Veterinary Research
• /
• v.48 no.3
• /
• pp.295-303
• /
• 2008

One hundred and sixty nine Escherichia (E.) coli strains isolated from fecal samples of aquatic birds in Geumho river basin and Dalseong park were tested by agar dilution method to determine their susceptibility patterns to 14 antimicrobial agents. The distribution of tetracycline resistance determinants (tetA, tetB, tetC, tetD and tetE) were also examined by PCR in 76 tetracycline-resistant ($TC^r$) E. coli isolates. The high resistance was observed in tetracycline, cephalothin and ampicillin (45.0~36.7%). Resistance of E. coli isolates derived from Dalseong park to tetracycline, cephalothin, ampicillin and streptomycin (65.7~44.8%) were significantly higher than those isolated from Geumho river basin (31.4~14.7%). About seventy percent (70.4%) of the strains isolated were resistant to one or more drugs tested. Thirty (39.5%) of 76 $TC^r$ E. coli isolates which were resistant to one or more drugs transferred all or a part of their resistance patterns to the recipient strain of E.coli J53 by conjugation. All of $TC^r$ E. coli isolates contained at least one or more of 5 tet genes examined. The most common genes found in these isolates were tetA (60.6%) and followed by tetB (7.9%) and tetC (1.3%). However, tetD and tetE were not found in any of the isolates tested. Twenty one (27.6%) of $TC^r$ E. coli isolates had two determinants, tetA/tetB (20 strains), tetA/tetC (1 strain). And two strains (2.6%) contained three determinants (tetA/tetB/tetC).

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