Best therapeutic practices for the use of antibacterial agents in finfish aquaculture: a particular view on European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) in Mediterranean aquaculture

open7siAntibacterial therapy is still in many cases the only way to control bacterial disease outbreaks, with relevant economic issues. Nevertheless, this necessity should also be well balanced with other relevant aspects such as suitability, efficacy and refinement of the treatments but also with consumer and environmental welfare. With this aim, the literature pertaining to the use of antibacterials (i.e. oxytetracycline, oxolinic acid, flumequine and potentiated sulphonamides) in Mediterranean farmed European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) was reviewed and addressed. Knowledge of drug pharmacokinetics along with the related legislation is also presented. The main criteria, technical aspects and constraints affecting the design of an appropriate antibacterial therapy are also discussed. An evaluation of available bibliography revealed the existence of considerable information on several registered antibacterials, while it is limited for others. Typically, minimum inhibitory concentrations (MIC) have been used as a reference for antibacterial selection. However, the methodologies used for MIC assessment require refinement and more sophisticated data such as epidemiological cut-off breakpoint values. Due to the characteristics of farming systems, antibacterials are mostly delivered through medicated feeds. The large number of production units and number of fish per unit, together with a limited timeframe margin for efficient therapy, makes Mediterranean gilthead seabream and European seabass, one of the best examples where the metaphylactic concept has to be considered in aquatic medicine. The information presented in this review should guide future action taken to fulfil research gaps and promote effective and prudent antibacterial practices.openRigos G.; Kogiannou D.; Padros F.; Cristofol C.; Florio D.; Fioravanti M.; Zarza C.Rigos G.; Kogiannou D.; Padros F.; Cristofol C.; Florio D.; Fioravanti M.; Zarza C

Effect of ivermectin on the liver of gilthead seabream Sparus aurata: a proteomic approach

23 p., 2 tablas, 4 figuras y bibliografíaGilthead sea bream Sparus aurata is the most commercialized Mediterranean aquacultured fish species. Ivermectin has recently(experimentally) started to be used to control ectoparasitic infestations in Mediterranean cultured marine fish. The potential hepatotoxicity of ivermectin was investigated in gilthead sea bream juveniles (35g) following oral administration at the recommended dose of 0.2mg kg-1 fish for 10d. Difference Gel Electrophoresis Technology (DIGE) was used to study the effect of this treatment in gilthead sea bream liver protein profile under routine culture conditions. The 2D-DIGE protein maps obtained were analyzed using the DeCyder 6.5 software. The results obtained showed significant changes in the expression of 36 proteins respect to the control group. Among these proteins, six increased in abundance, and 30 decreased. Spot showing differential expression respect to the control were analyzed by mass spectrometry and database search, which resulted in three positive identifications corresponding to hepatic proteins involved in lipid metabolism (apoA-I), oxidative stress responses and energy generation (beta-globin, ATP synthase subunit beta). These proteins have not been previously associated to invermectin effect.This work was funded by projects GV06B-351 “Generalitat Valenciana” and CTM 2006-14279-CO2-01/MAR MEC-FEDER. This research was performed within the framework of a concerted action between Spain and Greece (HG-2004-0016). I. Varó was a recipient of a “Ramón y Cajal” contract at the University of Valencia from the “Ministerio de Educación y Ciencia (Spain)”.Peer reviewe

Sol–Gel Synthesis and Characterization of YSZ Nanofillers for Dental Cements at Different Temperatures

From MDPI via Jisc Publications RouterHistory: accepted 2021-10-26, pub-electronic 2021-10-29Publication status: PublishedFunder: The project is co-financed by Greece and the EuropeanUnion (European Social Fund-ESF) by the Operational Program Human Resources Development,Education and Lifelong Learning 2014–2020.; Grant(s): MIS5047876Background: Yttria-stabilized zirconia nanoparticles can be applied as fillers to improve the mechanical and antibacterial properties of luting cement. The aim of this study was to synthesize yttria-stabilized zirconia nanoparticles by the sol–gel method and to investigate their composition, structure, morphology and biological properties. Methods: Nanopowders of ZrO2 7 wt% Y2O3 (nY-ZrO) were synthesized by the sol–gel method and were sintered at three different temperatures: 800, 1000 and 1200 °C, and their composition, size and morphology were investigated. The biocompatibility was investigated with human gingival fibroblasts (hGFs), while reactive oxygen species (ROS) production was evaluated through fluorescence analysis. Results: All synthesized materials were composed of tetragonal zirconia, while nanopowders sintered at 800 °C and 1000 °C additionally contained 5 and 20 wt% of the cubic phase. By increasing the calcination temperature, the crystalline size of the nanoparticles increased from 12.1 nm for nY-ZrO800 to 47.2 nm for nY-ZrO1200. Nano-sized particles with good dispersion and low agglomeration were received. Cell culture studies with human gingival fibroblasts verified the nanopowders’ biocompatibility and their ROS scavenging activity. Conclusions: the obtained sol–gel derived nanopowders showed suitable properties to be potentially used as nanofillers for dental luting cement

The kinetic behaviour of oxytetracycline and oxolinic acid euryhaline farmed fish species ('Spaaidale')

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The kinetic behaviour of oxytetracycline and oxolinic acid euryhaline farmed fish species ('Spaaidale')

This Phd thesis presents an extensive investigation of the kinetic behaviour of oxolinic acid (OA) and oxytetracycline (OTC) in Gilthead Sea Bream (GSB) (“Sparus aurata” L.) and Sharpsnout Sea Bream (SSB) (“Diplodus puntazzo” Cetti, 1777) at 19-20[sup]oC. The distribution half-life (t[sub]1/2[alpha]) and the elimination half-life (t[sub]/2[beta]) of OA from GSB plasma were found to be short (0.5 and 12h respectively) while longer values were estimated for OTC (2 and 53h respectively). Similarly, in SSB, calculated t[sub]1/2[alpha] and t[sub]1/2[beta] revealed values of 0.4 and 10h, respectively. The corresponding values for OTC were 1.4 and 34h. The apparent volume of distribution at steady-state (V[sub]d(ss)) of OA was identical in the two species (2Ikg[sup]-1). Higher V[sub]d(ss) values of OTC were found in both sparids (2.9 and 4lkg[sup]-1 for GSB and SSB, respectively). The bioavailabilities (F%) of OA and OTC following oral administration were found to be low in GSB (14 and 9% respectively). In SSB, the F of OA was calculated to be 15% while absorption of OTC was totally inhibited. The apparent digestibility of OTC was determined to be 27% in GSB and 40% SSB. However, the apparent digestibility of OA in both fish was considerably higher (92%; GSB, 88%; SSB). The tissue distribution and residue depletion of OA in both sparids revealed that OA is eliminated from edible tissues rapidly, allowing short withdrawal times. Short and long withdrawal times for OA and OTC respectively, are shown in this work to be necessary for safe human consumption of treated fish. All experiments in this work indicated reduced absorption of both drugs, which would result in significant release of the drugs in the vicinity of aquatic farms using sparids. This poses an environmental concern because of the potentially rapid development of a resistant aquatic bacterial population and possible adverse effects for other organisms in the habitat. Also there are potential financial losses associated with drug losses to the environment. Therefore, low drug absorption is clearly undesirable and studies to improve their absorption in sparids for future therapies is of vital importance

Experimental infection model with the bivalvulid Enteromyxum leei (Myxidiidae) in the sharpsnout seabream, Diplodus puntazzo (Sparidae), and evaluation of the antiparasitic efficacy of a functional diet

An infection model for sharpsnout seabream Diplodus puntazzo (Walbaum) challenged with the myxosporean Enteromyxum leei (Diamant, Lom et Dykova, 1994), resembling the natural infection conditions, was used to evaluate the antiparasitic efficacy of a functional diet. Fish of an average weight of 12.5 ± 1.2 g were delivered either a functional (included as feed supplement at 0.3% levels) or a control extruded diet. After four weeks of administration of the experimental diets, fish were challenged with the parasites (cohabitation with infected donors; donor: recipient ratio 1: 1). The experiment was terminated four weeks after the start of the challenge. At the end of the experiment, growth and feeding (specific growth rate and feed efficiency), as well as immunological parameters (respiratory burst activity, antibacterial activities, hemoglobin concentration, anti-protease activity and ceruloplasmin activity) were measured along with cumulative mortality and total parasitic count in the gut. No significant difference was evident with regard to growth and feeding performance, mortality, gut parasitic load or immunological parameters as the parasitical challenge significantly affected both the performance of the control and functional diet fed fish. However, there was a less prominent impact on antibacterial, anti-protease and ceruloplasmin activity in fish fed with the functional diet. Overall, the present study validated the experimental cohabitation infection model and evaluated the efficacy of a functional ingredient as an antiparasitic agent, showing some potential effects on the fish immune response.This work was made possible through a H2020-SFS-2014-2015 project entitled: ParaFishControl: Advanced Tools and Research Strategies for Parasite Control in European farmed fish (grant agreement no: 634429)

Evaluation of Praziquantel Efficacy against Zeuxapta seriolae Infections in Greater Amberjack, Seriola dumerili

The aim of this study was to evaluate the efficacy of dietary praziquantel (PZQ), a promising fish anthelminthic, against Zeuxapta seriolae, a lethal ectoparasite of greater amberjack (Seriola dumerili Risso) farmed in the Mediterranean and elsewhere. The trial was carried out in small cages (3 m3) in situ, harbouring fish (125 ± 14 g) naturally infected with Z. seriolae, at 25 ± 1 °C water temperature. Praziquantel-medicated diet (150 mg PZQ/kg fish) was delivered for three days against a control group. Measurement of both adults and oncomiracidia of Z. seriolae in sampled gill arches revealed significant differences between the tested groups (PZQ: 19.3 ± 9.8 vs. Control: 3.8 ± 6.3). Considering an estimated efficacy of 80.4% in the medicated fish, the present study indicates that oral PZQ treatments can confront Z. seriolae infections considerably in farmed greater amberjack and, perhaps, replace the commonly used hydrogen peroxidase baths

Effect of ivermectin on the liver of gilthead seabream Sparus aurata: a proteomic approach

23 p., 2 tablas, 4 figuras y bibliografíaGilthead sea bream Sparus aurata is the most commercialized Mediterranean aquacultured fish species. Ivermectin has recently(experimentally) started to be used to control ectoparasitic infestations in Mediterranean cultured marine fish. The potential hepatotoxicity of ivermectin was investigated in gilthead sea bream juveniles (35g) following oral administration at the recommended dose of 0.2mg kg-1 fish for 10d. Difference Gel Electrophoresis Technology (DIGE) was used to study the effect of this treatment in gilthead sea bream liver protein profile under routine culture conditions. The 2D-DIGE protein maps obtained were analyzed using the DeCyder 6.5 software. The results obtained showed significant changes in the expression of 36 proteins respect to the control group. Among these proteins, six increased in abundance, and 30 decreased. Spot showing differential expression respect to the control were analyzed by mass spectrometry and database search, which resulted in three positive identifications corresponding to hepatic proteins involved in lipid metabolism (apoA-I), oxidative stress responses and energy generation (beta-globin, ATP synthase subunit beta). These proteins have not been previously associated to invermectin effect.This work was funded by projects GV06B-351 “Generalitat Valenciana” and CTM 2006-14279-CO2-01/MAR MEC-FEDER. This research was performed within the framework of a concerted action between Spain and Greece (HG-2004-0016). I. Varó was a recipient of a “Ramón y Cajal” contract at the University of Valencia from the “Ministerio de Educación y Ciencia (Spain)”.Peer reviewe