Nanoparticles and microparticles of polymers and polysaccharides to administer fish vaccines

Aquaculture has become an important economic sector worldwide, but is faced with an ongoing threat from infectious diseases. Vaccination plays a critical role in protecting commercially raised fish from bacterial, viral and parasitic diseases. However, the production of effective vaccines is limited by the scarcity of knowledge about the immune system of fish. Improving vaccines implies using antigens, adjuvants and employing methods of administration that are more effective and less harmful to the fish. In this context, in recent year there have studies of methods of encapsulating antigens in matrices of different types to apply in fish vaccines. This work reviews the new methods to improve fish vaccines by encapsulating them in polymers and polysaccharides

Quality appraisal of clinical practice guidelines on provision of dental services during the first months of the COVID-19 pandemic

Objectives: To evaluate the quality of clinical practice guidelines (CPGs) on dental services provision during the first months of the COVID-19 pandemic. Materials and methods: We systematically searched in MEDLINE, EMBASE, LILACS, Epistemonikos, Trip databases, websites of CPG developers, compilers of CPGs, scientific societies and ministries of health to identify documents with recommendations intended to minimize the risk of COVID-19 transmission during dental care. Reviewers independently and in duplicate assessed the included CPGs using the AGREE II instrument. We calculated the standardized scores for the 6 domains and made a final recommendation about each CPG. The inter-appraiser agreement was assessed using the intraclass correlation coefficient (ICC). Results: Twenty-three CPGs published were included. Most of the CPGs were from America (n = 15) and Europe (n = 6). The overall agreement between reviewers was very good (ICC = 0.93; 95%CI 0.87-0.95). The median score for each domain was the following: Scope and purpose 67% (IQR 20%); Stakeholder involvement 33% (IQR 14%); Rigour of development 13% (IQR 13%); Clarity of presentation 64% (IQR 31%); Applicability 19% (IQR 17%) and Editorial independence 8% (IQR 8%). Twenty two guidelines were not recommended by the reviewers. Only one of the CPGs was recommended with modifications. The median overall rate was 3 (IQR 1). All CPGs were classified as low quality. Conclusions: The overall quality of CPGs on dental services provision during the first months of the COVID-19 pandemic was low, which makes its implementation difficult for clinicians and policy makers. Therefore, it is critical that developers are transparent and forthcoming about the difficulties that have arisen during the CPG development process

Labelling fish diets with 15N ‐Leucine for monitoring feed consumption and bio‐distribution in Atlantic salmon

Abstract Feeding represents 50–70% of the cost of production in salmon farming, higher than any other animal farm. The improvement of this percentage is challenging as the food is thrown into the fish tank, there is no quantification of the amount of food that is consumed by the fish. In consequence, it is difficult to adjust the food composition making it more nutritive or promoting food consumption by fish. In this study, to investigate food consumption, bio‐distribution and food residues, leucine containing 15N (a stable isotope of nitrogen) was used to label the fish food. Atlantic salmon (Salmo salar) weighing 100–120 g were maintained in 30 L tanks at a density of 14 kg/m3. Fishes were fed daily at 1% of the fish weight with pellet labelled with 15N‐leucine. The 15N incorporation was determined 14 hours after the feeding in all the fish organs. Results showed that 14 hours after the administration of a single dose of labelled food to Atlantic salmon enables the detection of the tracer in the whole organism allowing determining the food consumption. Through the analysis of nitrogen use efficiency (NUE), we showed that the trunk, pyloric caeca and head incorporate the highest level of the marker (72.7, 8.7 and 5.7%, respectively). This methodology would permit monitoring feeding to minimize food loss, improve administration methodologies or select the preferred foods for the fish, among others to reduce production costs

Development of a nanoparticle-based oral vaccine for Atlantic salmon against ISAV using an alphavirus replicon as adjuvant

Adjuvants used in vaccine aquaculture are frequently harmful for the fish, causing melanosis, granulomas and kidney damage. Along with that, vaccines are mostly administered by injection, causing pain and stress to the fish. We used the DNA coding for the replicase of alphavirus as adjuvant (Ad) of a vaccine against ISAV. The Ad and an inactivated ISAV (V) were loaded in chitosan nanoparticles (NPs) to be administered orally to Atlantic salmon. NP-Ad was able to deliver the DNA ex vivo and in vivo. Oral administration of the NPs stimulated the expression of immune molecules, but did not stimulate the humoral response. Although the vaccination with NP-V results in a modest protection of fish against ISAV, NP-V administered together with NP-Ad caused a protection of 77%. Therefore, the DNA coding for the replicase of alphavirus could be administered orally and can potentiate the immuneprotection of a virine against infection.Fil: Rivas Aravena, Andrea. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; Chile. Comision Chilena de Energía Nuclear. Departamento de Aplicaciones Nucleares; ChileFil: Fuentes, Jazmin. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; ChileFil: Cartagena, Julio. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; ChileFil: Brito, Tania. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; ChileFil: Poggio, Thelma Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; Argentina. Tecnovax; ArgentinaFil: la Torre, Jose Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; Argentina. Tecnovax; ArgentinaFil: Mendoza, Hegaly. Universidad Andr és Bello. Center for Bioinformatics and Integrative Biology; ChileFil: Gonzalez Nilo, Fernando Danilo. Universidad Andr és Bello. Center for Bioinformatics and Integrative Biology; ChileFil: Sandino, Ana María. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; ChileFil: Eugenio, Emilio Osvaldo. Universidad de Santiago. Facultad de Química y Biología. Centro de Biotecnología Acuícola. Laboratorio de Virología; Chil