Aquaculture Drugs Research Articles

Screening of Antagonistic Bacteria against Three Aquatic Pathogens and Characterization of Lipopeptides in Bacillus cereus BA09.

Screening for antagonistic bacteria on aquatic pathogens and identification of antagonistic ingredients are essential to reduce the use of chemicals in aquaculture. In this study, strain BA09, subsequently identified as Bacillus cereus, simultaneously displayed strong antagonistic effects on Edwardsiella tarda, Vibrio harveyi, and Streptococcus anisopliae in the initial screening and rescreening. In addition, the methanol extract of BA09 was subjected to antibacterial activity verification and one-dimensional (1D) reversed-phase liquid chromatography (RPLC) preparation. A total of 27 fractions were collected, 6 of which were subjected to two-dimensional (2D) RPLC separation and tracked as antibacterial. A total of 14 lipopeptides that included 9 fengycin homologs, 3 bacillomycin homologs, and 2 surfactin homologs were identified by tandem high-resolution mass spectrometry. Through characterization of the antibacterial substance in Bacillus cereus BA09, which simultaneously inhibited E. tarda, V. harveyi, and S. agalactiae, the current study provides a theoretical basis for the development of antibacterial drugs in aquaculture.

Application potential of albendazole as an aquatic animal drug based on its safety, efficacy, and residue profiles.

The number of available drugs for treating aquatic animals is insufficient, given the occurrence of a variety of parasites and difficulties in developing appropriate treatments, such as vaccines or immunostimulants. Consequently, repurposing livestock drugs for treating aquatic animals is a viable alternative. Several studies have demonstrated that albendazole (ABZ) is a good anthelmintic for humans and animals such as ruminants, poultry, and honeybees. Therefore, we investigated the toxicological studies, metabolic and residue depletion studies, and efficacy trials of ABZ in aquatic animals to identify its application potential as a drug for aquatic animals. ABZ was depleted within 24h in the muscle tissues of hybrid striped bass, rainbow trout, and tilapia. In muscle tissue with adhering skin obtained from tilapia and largemouth bass, a significant quantity of the amino-sulfone metabolite of ABZ (ABZ-SO2NH2) was present, while no ABZ-SO2NH2 was detected in hybrid striped bass, channel catfish, and patinga. Fish exposed only to high doses of ABZ showed reduced red blood cell counts and hemoglobin levels and increased lymphocytes. Such signs of toxicity have also been observed in human patients and animal studies. At a dose of 100mg/L, ABZ showed 100% efficacy in eels. In addition, albendazole sulfoxide (ABZSO) demonstrated efficacies of 96.1% and 100% in pirapatinga and ray-finned fish, respectively, at a dose 500mg/L. ABZ was also highly effective in treating an intracellular parasite E. hepatopenaei in white shrimp. The application of ABZ in aquatic animals under the low-dose and short-term conditions is considered a reasonable solution to manage parasite infections. The types and residual periods of degradation products differed among fish species, suggesting dissimilar metabolic pathways. With a high demand for new alternative veterinary drugs in aquaculture by fish farmers, this review offers important evidence for considering the use of ABZ in Korean farmed fish, taking food safety issues into account.

Simultaneous determination of methyltestosterone and its metabolite in fish by gas chromatography-mass spectrometry.

Methyltestosterone is one of the banned drugs in aquaculture, and it should be monitored in food-producing animals. 17α-Methyl-5β-androstane-3α,17β-diol, as the main metabolite of methyltestosterone in vertebrates, could be used as another marker for controlling the administration of methyltestosterone, due to its high residual concentration and slow elimination rate. In this study, an analytical method based on gas chromatography-mass spectrometry (GC-MS) was developed and validated for the simultaneous determination of methyltestosterone and its main metabolite in fish. After pretreatment by liquid-liquid extraction with n-hexane and solid phase extraction with C18 and NH2 columns, the target analytes in the muscle tissues were extracted and concentrated, and the influence of the sample matrix was eliminated. Then, the prepared samples were separated and detected with GC-MS in the selected ion monitoring (SIM) mode. Methyltestosterone-D3 was chosen as the internal standard for quantitation. After optimization, the limits of detection for methyltestosterone and 17α-methyl-5β-androstane-3α,17β-diol were 20 μg kg-1 and 15 μg kg-1, respectively. The limits of quantitation were both 50 μg kg-1. The calibration curves showed good linearity in the concentration range from 50.0 ng mL-1 to 500.0 ng mL-1. The correlation coefficients of methyltestosterone and 17α-methyl-5β-androstane-3α,17β-diol were more than 0.9990. The recoveries of the analytes in real samples were in the range of 99.7-116.6% with the relative standard deviation of 5.2-8.3%. The established method could meet the demand for simultaneous detection of methyltestosterone and its major metabolite, and it could be used to provide more information on the abuse of methyltestosterone in food-producing animals.

Оценка эффективности применения растворов химических веществ для лечебно-профилактической обработки икры белуги (Huso huso) от сапролегниоза

The results of experimental work on the treatment of beluga caviar with solutions of chemicals (0.9% sodium chloride, 0.05% hydrogen peroxide, 0.5% “Monclavit-1”, 0.01% “Iodinol”, 0.5% tannin), conducted with the aim of suppressing the growth and development of micromycetes sem. Saprolegniaceae, causing the disease of fish saprolegniosis. Saprolegnium micromycetes, affecting eggs during incubation, juveniles and adult fish, cause enormous damage to fish farms. Treatment of this disease is very difficult due to a number of restrictions imposed on the use of veterinary drugs in aquaculture. Evaluation of the effectiveness of the use of chemical solutions and their effects on the embryonic development of beluga (Huso huso) and the degree of infection of embryos with sem micromycetes. Saprolegniaceae was carried out according to fish-breeding and biological indicators (the proportion of fertilized eggs; the proportion of embryos infected with saprolegnium mycomycetes; the proportion of developing embryos; the number of abnormally developing oocytes and the proportion of hatched pre-larvae) at certain stages of development. Experimental work was carried out in production conditions in the incubation apparatus “Sturgeon” under optimal hydrochemical conditions for the development of beluga embryos. The experimental groups corresponded to the experimental concentrations of solutions. The most effective solutions that have an inhibitory effect on the growth and development of sem micromycetes. Saprolegniaceae, is a 0.05% solution of hydrogen peroxide with an exposure of 10 minutes and a 0.9% solution of sodium chloride with an exposure of 3 minutes. These solutions of substances suppressed the growth of saprolegnium micromycetes without adversely affecting the embryogenesis of beluga.

Gross yield driving the mass fluxes of fishery drugs: Evidence of occurrence from full aquaculture cycle in lower Yangtze River Basin

Expanding aquaculture has generated pollutants like fishery drugs in wastewater, which affects the aquatic environments and hinders sustainable development of aquaculture. To evaluate the occurrence, mass fluxes and production factors of fishery drugs in aquaculture, full-aquaculture-cycle monitoring in finfish and crustacean wastewater was conducted in the lower Yangtze River Basin, and 28 pesticides and 15 antibiotics were detected. The results showed that individual fishery drugs varied from ppt to ppb levels. Among them, sulfonamides were dominant with a mean concentration of 105.95 ± 4.13 ng·L−1 in finfish aquacultural wastewater, and insecticides were prevailing in crustacean aquacultural wastewater with a content of 146.56 ± 0.66 ng·L−1. Since the susceptibility to finfish disease determined the aquaculture practice, there were significant differences between two types of aquacultural wastewater. Finfish aquacultural wastewater contained more drugs and reached peak earlier in rapid-growth period, yet crustacean aquacultural wastewater peaked at the harvest period, to prevent against disease. Meanwhile, higher ecological risk, especially for florfenicol, were found in finfish wastewater. With 6 production factors from Good Aquaculture Practice, the gross yield was the most influential factor of drug mass flux, explaining 98 % variance by stepwise regression. Apart from increasing concentrations of fishery drugs in wastewater, regional high-yield aquaculture also significantly impacted the corresponding mass flux. As estimated by linear regression, 1.63 tons of target drugs would be discharged by 1 Mt. aquatic products, and 7.77 tons were discharged from aquaculture in the lower Yangtze River Basin in 2021. This is the first report to quantify mass fluxes of fishery drugs and to highlight gross yield as the most influential factor, which provides guidance for the supervision and regulation of sustainable aquaculture.

A review on the application of chicken immunoglobulin Y in aquaculture

AbstractThe widespread use of antimicrobial drugs in aquaculture has led to antibiotic residues in aquatic animals. Food safety problems caused by the misuse of antibiotics and antibiotic residues have caused widespread global concern. Consequently, there is an urgent need to develop an alternative to antibiotics for use in aquaculture. Immunoglobulin Y (IgY) has attracted significant attention over recent years because it is readily available, simple to prepare, effective in inhibiting pathogenic microorganisms, free from environmental contamination and free from other toxic side effects. In this paper, we review the research progress relating to the basic structure, physicochemical properties and mechanism of action of IgY. We also highlight the applications of IgY in the control of aquatic animal disease, immunological diagnosis and the preservation of aquaculture products, thus providing a reference for future research and the wider application of IgY in aquaculture.

In-vitro Antibacterial Potentials of Essential oil from Citrus limon against Selected Pathogenic Bacteria Isolated from Cultured Nile Tilapia (Oreochromis niloticus)

Essential oils (EOs) from medicinal plants like lemon (Citrus limon) are considered promising to replace synthetic antibiotics in aquaculture production due to their ability to improve fish health. The aim of the research was to investigate the in vitro antibacterial potentials of varying levels of lemon EO against Streptococcus agalactiae, Escherichia coli, Staphylococcus aureus and Aeromonas hydrophila isolated from Nile Tilapia. This research was conducted at the Microbiology unit., Kenyan Marine and Fisheries Research Institute, Mombasa, Kenya and Environmental Microbiology and Biotechnology Laboratory, Department of Microbiology, University of Ibadan, Ibadan, Nigeria in December 2021. Extraction of EO from lemon peel was performed using steam hydro distillation. The quantitative and qualitative profiling of extracted oil was performed using Gas Chromatography-Mass Spectrometry. The antibacterial potential of lemon EO was tested against some pathogens using the agar well diffusion method while the Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) were determined by the broth dilution method. The most abundant chemical was D-Limonene (37.56%), 3-Carene (15.88%) and Terpinen-4-ol (93.4%). The lemon EO at 100% and 50% concentration respectively showed the highest antibacterial activity against S. agalactiae (26.00mm and 28.33mm) and E. coli (33.00mm and 30.00 mm); while the least activity was observed against A. hydrophila (8.33mm and 6.67 mm) at P = .05. The MIC and MBC values revealed that 50% lemon EO inhibited bacterial growth for S. agalactiae whereas it was greater than 50% for S. aureus, E. coli and A. hydrophila. Lemon EO has potential antibacterial properties against tested pathogens that affect cultured fish and could be considered a good candidate for further research to develop new antibacterial drugs in aquaculture.

Synthesis and anti-parasites efficacy of coumarin derivatives against Dactylogyrus intermedius.

Dactylogyrus is one of the most common parasitic diseases in fish and causes huge losses to the aquaculture industry. With the advantages of safety, low toxicity and easy degradation, plant-derived drugs are ideal for the creation of green aquatic ingredients. The use of plant-derived drugs in aquaculture is limited by their low content and high processing costs, which is a challenge that can be solved by the chemical synthesis of plant-derived drugs. Eleven new coumarin derivatives were synthesized and assessed for their anthelmintic activity in this study. Among them, the derivative 7-((1-tosyl-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (N11) has good anthelmintic activity and its mean anthelmintic efficacy against D. intermedius at a concentration of 10 μM reached 99.84%, which is even better than the anthelmintic activity of the positive control mebendazole. Further studies showed that N11 had concentration values of 3.31 and 1.94 μM for 50% maximal effect (EC50 ) against D. intermedius at 24 and 48 h, respectively. Furthermore, scanning electron microscopy revealed that N11 caused damage to D. intermedius. What is more noteworthy is that a substantial reduction in the ATP content of the parasite was observed following in vitro and in vivo administration of N11. Moreover, it was also found that N11 was able to inhibit the horizontal transmission of D. intermedius. Furthermore, real-time quantitative PCR analysis was utilized to determine the expression profile of genes associated with anti-inflammatory cytokines (IL-10, TGF-β and IL-4) in goldfish. In all examined organs, it was observed that the expression of anti-inflammatory cytokines increased subsequent to treatment with N11, according to the results. Thus, these results all suggest that N11 possesses good anthelmintic activity and is a potentially effective agent for the control of D. intermedius.

The antiviral activity of currently used medicinal plants in aquaculture and structure–activity relationship of their active ingredients

AbstractAquaculture is an important source of high‐quality protein and plays a crucial role in ensuring global food security. However, viral diseases have caused significant damage to aquaculture production, making it necessary to develop effective measures to treat them. Although drugs are commonly used to treat viral diseases, recent studies have shown that crude extracts of medicinal plants and their active ingredients have potential applications in the treatment of aquatic viral diseases. Furthermore, natural small molecule compounds from herbs could be used as lead compounds to develop more potent anti‐aquatic virus derivatives. As such, there is an urgent need to develop and apply drugs for the treatment of viral disease outbreaks in aquaculture. In this review, we summarize previous studies on the efficacy of different agents used as antiviral drugs in aquaculture, with a focus on their protective effects. Additionally, we highlight the potential of active natural compounds isolated from medicinal plants, which could serve as lead compounds for developing aquatic‐specific drugs. However, the relationship between the structure of a compound and its antiviral activity in aquaculture has not been clearly elucidated, posing a challenge for further drug optimisation. Therefore, this study also analyses the structure–activity relationship of several reported lead compounds and their derivatives in aquaculture, providing a reference for subsequent drug development efforts.

Phish-Pharm: A Searchable Database of Pharmacokinetics and Drug Residue Literature in Fish - 2022 Update.

A new version of Phish-Pharm: a Searchable Database of Pharmacokinetics and Drug Residue Literature in Fish has been updated and posted online at: http://www.fda.gov/AnimalVeterinary/ScienceResearch/ToolsResources/Phish-Pharm/default.htm . The new version contains over 700 articles encompassing 191 aquatic species (fish, shellfish, and more).Phish-Pharm, first released in 2005, accompanied an article in this Journal, titled "Fish Drug Analysis-Phish-Pharm: A Searchable Database of Pharmacokinetics Data in Fish," by R. Reimschuessel, L. Stewart, E. Squibb, K. Hirokawa, T. Brady, D. Brooks, B. Shaikh, C. Hodsdon, AAPS Journal. 2005;07(02):E288-E327, article 30. ( https://link.springer.com/article/10.1208/aapsj070230 )FDA understands that there are limited approved, conditionally approved, or indexed drugs available for use in aquatic animals. In response, FDA made this reference database publicly available to assist investigators in developing new animal drugs for aquatic species. The database also supports FDA Center for Veterinary Medicine's mission of protecting human and animal health by serving as a resource for the aquatic drug approval process and drug residue surveillance.Phish-Pharm is a Microsoft Access database that is periodically updated. Searchable fields include pharmacokinetic data and links to the abstract for each article. Phish-Pharm enables users to evaluate information on drugs and chemicals and to identify research gaps to guide future research. Phish-Pharm is not intended for aquaculture farmers to evaluate safety or effectiveness of unapproved drugs. Phish-Pharm is not an appropriate tool for recommending withdrawal intervals of drug and chemical residues due to variability among studies. Aquaculture farmers should only use approved, conditionally approved, or indexed drugs in their operations (see Approved Aquaculture Drugs ).

Natural Materials Modified and Applied to the Detection of Drugs In Situ: Modification of Eggshell and Quantification of Oxytetracycline.

This work describes a novel sensing system using eggshells as substrate for the first time, targeting the detection and semiquantitative determination of antibiotics in waters from aquaculture, enabling simple, inexpensive, and in situ drug monitoring. Eggshell was ground and the resulting powder was modified by adsorption of suitable reagents, and it takes a typical colour after contact with the antibiotic. The colour intensity is correlated with the concentration of the antibiotic. This novel approach was applied to oxytetracycline, one of the antibiotics commonly used in aquaculture. The chemical changes on the eggshell powder were evaluated and optimised to produce an intense colour change as a function of the concentration of the antibiotic. The colour changes were evaluated by visual comparison with images taken with a digital camera, applying an appropriate mathematical treatment to the colour coordinates of the HSL system used by Windows. The selectivity of the response was tested against other antibiotic drugs. The materials were also used in the analysis of a spiked environmental water sample. Overall, this work presents a rapid, inexpensive, simple and equipment-free method for screening and discrimination of tetracycline drugs in aquaculture. The method is a green approach by reusing eggshells and decreasing the level of contamination correlated to analytical methods, thus being a promising tool for local, rapid, and cost-effective antibiotic monitoring.

Synergistic Effect of Quercetin on Antibacterial Activity of Florfenicol Against Aeromonas hydrophila In Vitro and In Vivo.

The overuse or abuse of antimicrobial drugs in aquaculture, aggravates the generation of drug-resistant bacteria, which has caused potential risks to human health and the aquaculture industry. Flavonoid–antibiotic combinations have been shown to suppress the emergence of resistance in bacteria, and sometimes even reverse it. Here, the antibacterial activity of florfenicol in combination with quercetin, a potential drug to reverse multidrug resistance, was tested against Aeromonas hydrophila (A. hydrophila). Of eleven selected antimicrobial agents, quercetin and florfenicol showed the strongest bactericidal effect, and fractional inhibitory concentration (FIC) indices were 0.28, showing a highly synergistic effect. Then, the antibacterial activities of quercetin and florfenicol against A. hydrophila were further tested in vitro and in vivo. Bacterial viability of A. hydrophila decreased in a florfenicol dose-dependent manner, about 16.3–191.4-fold lower in the presence of 15 μg/mL quercetin and 0.156 to 1.25 μg/mL florfenicol than in the absence of quercetin, respectively. The cell killing was maximum at 45 μg/mL quercetin in the dose range tested plus 0.156 μg/mL florfenicol. The viability decreased over time during the combined treatment with quercetin and florfenicol by 60.5- and 115-fold in 0.156 μg/mL florfenicol and 0.625 μg/mL florfenicol, respectively. Additionally, the synergistic effect was confirmed by the bacterial growth curve. Furthermore, quercetin and florfenicol had an obvious synergistic activity in vivo, reducing the bacterial load in the liver, spleen and kidney tissues of Cyprinus carpio up to 610.6-fold compared with the florfenicol group, and improving the survival rate of infected fish from 10% in the control group to 90% in drug combinations group. These findings indicated that quercetin could potentiate the antibacterial activity of florfenicol against A. hydrophila infection and may reduce the use of antimicrobial drugs and improve the prevention and control capability of bacterial resistance.

Pyocyanin as a safe aquaculture drug for the control of vibriosis in shrimp recirculating aquaculture system (RAS)

Pyocyanin as a safe aquaculture drug for the control of vibriosis in shrimp recirculating aquaculture system (RAS)

ESSENTIAL OILS AS THERAPEUTIC AND PROPHYLACTIC AGENTS AND FEED ADDITIVES FOR AQUACULTURE (REVIEW)

Purpose. Generalization and analysis of articles concerning the use of essential oils as components of aquaculture feeds and disinfectants to obtain information about the technology of their preparation and use as well as about their influence to the quality of fish feeds and their health.
 Materials and methods. A selection and systematic review of scientific literature on the research topic for the period 2011-2021 was carried out. Keyword searches were performed in bibliographic databases to select scientific articles.
 Results. Essential oils can be used in aquaculture as an effective treatment and prevention of infectious diseases, to control parasites, to improve the health of fish as immunostimulants, antioxidants and growth stimulants. But most of the studies were based on in vitro tests or were carried out under laboratory conditions, so their results need to be clarified under production conditions. It also needs to be established precisely which active substances in essential oils are responsible for their therapeutic effect. The active application of essential oils in aquaculture is hampered by their insufficient stability during feed preparation, storage and passage through the gastrointestinal tract of fish. Microencapsulation technology is recommended to overcome this disadvantage.
 Conclusion. The use of essential oils as therapeutic and prophylactic agents and feed additives is a promising strategy to reduce the use of traditional synthetic drugs in aquaculture. To effectively use foreign scientific results in Russian aquaculture, it is necessary to conduct research on replacement of essential oils obtained from exotic plants with oils from plants cultivated in our country based on the similarity of their composition.

Rapid determination of antiviral drugs in yellow catfish (Pelteobagrus fulvidraco) using graphene/silica nanospheres (G/KCC-1) based pipette tip solid-phase extraction with ultra-performance liquid chromatography-tandem mass spectrometry

Yellow catfish (Pelteobagrus fulvidraco) is commonly contaminated by protease inhibitors because of the illegal use of antiviral drugs in aquaculture, so the determination of antiviral drugs is essential in food safety supervision. In this study, a novel sorbent, graphene and silica nanospheres composite (G/KCC-1), was synthesized for pipette-tip-based solid-phase extraction (PT-SPE) and purification of ritonavir, saquinavir, and indinavir in yellow catfish, followed by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS) analysis. The wrinkly structure of G/KCC-1 with center-radial nanowrinkles enlarged the surface area and increased the capacity of absorbing the target analyte. With the proposed G/KCC-1 based PT-SPE UPLC-MS/MS method, the pH of sample solution, aspirating/dispensing cycles for extraction and elution were optimized to be 4.0, 25, and 10 respectively, and the eluting solvent was methanol/ammonia (95:5, v/v) with 0.02 M sodium chloride. This new method was further validated to be linear (correlation coefficient R2, 0.9993–0.9996), sensitive (limit of detection, LOD ≤ 0.8 ng mL−1), accurate (89.3–114.2%), and precise (relative standard deviation, RSD ≤ 6.23%). These results indicated that the proposed method is qualified in bioanalytical method validation and meets the requirements for detecting illegally used antiviral drugs in yellow catfish. The demonstrated G/KCC-1 based PT-SPE UPLC-MS/MS method is a potential analytical method in food and drug administration.

Modeling the distribution of malachite green in zebrafish using matrix-assisted laser desorption/ionization mass spectrometry imaging.

Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Here, a rapid and effective analysis strategy was introduced to study the distribution of veterinary drugs in aquatic products. Malachite green (MG), one of the most widely used veterinary drugs in aquaculture, was selected as the targeted compound. Zebrafish (Danio rerio) was used as a model organism. After an exposure test, the matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technique was applied to directly analyze the content changes of malachite green in zebrafish tissues. The reliable relationship of exposure time and content change of MG was described precisely by the extended Freundlich equation. The process of modeling was discussed in detail, and some important parameters or trend information was obtained, including the maximum content of MG in different fish tissues, time to maximum content, elimination time, equilibrium content, and so on. With a simplification of sample pretreatment, this research strategy can be used for monitoring the spatial distribution of veterinary drugs and related metabolites of laboratory-exposed fish. The obtained model can provide a perspective for rational drug use in aquaculture and precise drug residue detection in production activities.

Evaluation on the antiviral activity of ribavirin against Micropterus salmoides rhabdovirus (MSRV) in vitro and in vivo

Micropterus salmoides rhabdovirus (MSRV) causes a severe lethal infection in largemouth bass fry, resulting in great economic loss. However, there is no effective drug to control this viral infection. In this study, a screening assay based on real-time quantitative PCR (RT-qPCR) was firstly performed, and the results showed that ribavirin exhibited the best antiviral activity, with a 48 h-IC50 (inhibitory concentration at half-maximal activity) of 1.21 μM and significantly reduced the viral titer at 24 h post infection (P < 0.01). Furthermore, ribavirin protected the MSRV-infected cells against CPE (cytopathic effect) and nuclear damage, and significantly increased cell viability after this virus infection (P < 0.05). In addition, a series of four assays were performed in order to evaluate the potential mechanism of ribavirin against MSRV infection in GCO cells. Our results indicated that ribavirin reduced the infectivity of MSRV, repressed early virus replication and inhibited release of the viral particles. Finally, the data from two in vivo assays showed that ribavirin had a significant preventive effect against MSRV infection in largemouth bass. A single intraperitoneal administration of 100 mg/kg ribavirin at 4 days before the viral challenge increased the survival rate of largemouth bass by 30%, and significantly reduced viral loads in the liver, spleen and kidney of fish (P <0.01). Besides, the survival rate of largemouth bass orally administrated with 100 mg/kg ribavirin was improved significantly at 4 days post MSRV infection (P < 0.05), and the viral load in the liver, spleen, and kidney was also decreased significantly during 5 days post the infection (P < 0.01). Overall, ribavirin exhibited a good antiviral effect against MSRV infection both in vitro and in vivo, and this finding may provide a reference for discovery and development of anti-MSRV drugs in aquaculture.

Cu-BTC frameworks based electrochemical sensor for hazardous malachite green in aquaculture

Malachite green (MG) has been widely used for controlling external fungi and parasites in the aquaculture. However, MG has been proven to be very hazardous, and the detection of MG in aquaculture environment is crucial for determining whether MG has been used within the allowed limit and for protecting the environment. Herein, a kind of copper based metal-organic frameworks (MOFs) was prepared using copper nitrate and 1,3,5-benzenetricarboxylic acid (H3BTC) as raw materials. The prepared Cu-BTC materials provide larger active area and higher accumulation capacity for MG, and meanwhile lower the charge-transfer resistance. As a result, the oxidation signal and detection sensitivity of MG are significantly improved by Cu-BTC frameworks. The linear range is 2–500 nM, and the detection limit is 0.67 nM, which is much lower than the reported values. Moreover, other usually-used aquaculture drugs have no interferences, including erythromycin, chloramphenicol, oxytetracycline, furazolidone and nitrofurazone. This method was applied in the water samples, and the results were consistent with those using high-performance liquid chromatography.

Veterinary Drug Residues in Animal-Derived Foods: Sample Preparation and Analytical Methods.

Veterinary drugs are used to treat livestock and aquatic diseases and thus are introduced into animal-derived foods, endangering consumer health and safety. Antibiotic resistance is rapidly becoming a major worldwide problem, and there has been a steady increase in the number of pathogens that show multi-drug resistance. Illegal and excessive use of veterinary drugs in animals and aquaculture has serious adverse effects on humans and on all other environmental organisms. It is necessary to develop simple extraction methods and fast analytical methods to effectively detect veterinary drug residues in animal-derived foods. This review summarizes the application of various sample extraction techniques and detection and quantification methods for veterinary drug residues reported in the last decade (2010-2020). This review compares the advantages and disadvantages of various extraction techniques and detection methods and describes advanced methods, such as those that use electrochemical biosensors, piezoelectric biosensors, optical biosensors, and molecularly imprinted polymer biosensors. Finally, the future prospects and trends related to extraction methods, detection methods and advanced methods for the analysis of veterinary drug residues in animal-derived foods are summarized.

Aquaculture drug degradation in persulfate by PANI-based microparticles controlled via ultrasonic field: Forced motion of “burning hot micromotors”

The triphenylmethane derivative malachite green (tpmMaG) despite repeated prohibitions but is frequently detected in aquatic environment and draws emerging attention because of the potential poisonous effects. The polyaniline/persulfate with ultrasound catalysis (US/PANI-PS) was developed for tpmMaG removal. The effects of 12 factors and the optimization by response surface methodology (RSM) for tpmFG removal were evaluated based on the pseudo-first-kinetics (kobs). From free radical inhibition, the ratios of active species in US/PANI-PS (δ11 = 0.355, δ12 = 0.593) were close to that in US-PS (δ21 = 0.346, δ22 = 0.586) and different to that in PANI-PS and PS systems. A possible degradation pathway (hydroxylation, N-demethylation, deamination, and open-benzene ring) was explored by gas chromatography-mass spectrometer (GC/MS) and high performance liquid chromatography-mass spectrometer (HPLC-MS). The designed reactor involving the US-driven PANI was simulated by acoustic-piezoelectric interaction. From cavitation calculations, the estimated effective-mean temperature at bubble-water interface had little increasing (from 704 K to 711 K) after adding the PANI, however, the adsorption capacity of tpmMaG in reactive zone decreased from 0.0891 μM to 0.0787 μM. The mechanism (PANI hot turbo-micromotors) with US/PANI-PS was proposed. The tpmMaG was removed with a low treatment cost of 2.81 $⋅m−3 (the EE/O value 18.29 kWh⋅m−3) by US/PANI-PS, presenting a cost-effective treating process. The reusability tests and characterizations (contact angle, X-ray diffraction (XRD), and scanning electron microscope (SEM)) further confirmed the stability of PANI.