The aquaculture supply chain in the time of covid-19 pandemic: Vulnerability, resilience, solutions and priorities at the global scale.

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

Review. Leukocyte and endothelial cell adhesion molecules in inflammation focusing on inflammatory heart disease.

In multicellular organisms the development of adhesion bonds, either among cells or among cells and components of the extracellular matrix, is a crucial process. These interactions are mediated by molecules which are named adhesion molecules and play a main role both at the early stages of the development of tissue integrity and later. Cell adhesion molecules (CAMs) have a key role in several pathologies such as cancer and inflammatory diseases. Selectins, integrins and immunoglobulin gene superfamily of adhesion receptors mediate different steps of leukocyte migration from the bloodstream towards the inflammatory foci. Leukocyte interactions with the vascular endothelium are highly orchestrated processes that include the capture of free-flowing leukocytes from the blood with subsequent leukocyte rolling, arrest, firm adhesion and ensuing diapedesis. These interactions occur under high shear stresses within venules and depend on multiple families of adhesion molecules. As a response to infection mediators, leukocyte gathering is considered to be crucial for the adequate defence of the organism to any kind of injury or infection. Endothelial activation contributes significantly to the systemic inflammatory response to bacteraemia and increased expression. Release of soluble endothelial markers into the circulation has been demonstrated together with elevated plasma levels of CAMs and has been reported in bacteraemic patients. It has been proposed that infection of endothelial cells with Staphylococcus aureus, Streptococcus sanguis, or Staphylococcus epidermidis induces surface expression of ICAM-1 and VCAM-1 and monocyte adhesion. In general, leukocyte/endothelial cell interactions such as capture, rolling, and firm adhesion can no longer be viewed as occurring in discrete steps mediated by individual families of adhesion molecules but rather as a series of overlapping synergistic interactions among adhesion molecules resulting in an adhesion cascade. These cascades thereby direct leukocyte migration, which is essential for the generation of effective inflammatory responses and the development of rapid immune responses.

Evaluation of candidate probiotic strains for gilthead sea bream larvae (Sparus aurata) using an in vivo approach.

AIMS: The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream larvae (Sparus aurata). METHODS AND RESULTS: Six bacterial strains isolated from well-performing live food cultures were identified by sequencing fragments of their 16s rDNA genome to the genus level as Cytophaga sp., Roseobacter sp., Ruergeria sp., Paracoccus sp., Aeromonas sp. and Shewanella sp. Survival rates of gilthead sea bream larvae transferred to seawater added these bacterial strains at concentrations of 6 +/- 0.3 x 10(5) bacteria ml(-1) were similar to those of larvae transferred to sterilized seawater and showed an average of 86% at 9 days after hatching, whereas, survival rates of larvae transferred to filtered seawater were lower (P < 0.05), and showed an average of 39%, 9 days after hatching. CONCLUSION: Several bacterial strains isolated from well-performing live food cultures showed a positive effect for sea bream larvae when compared with filtered seawater. SIGNIFICANCE AND IMPACT OF THE STUDY: The approach used in this study could be applied as an in vivo evaluation method of candidate probiotic strains used in the rearing of marine fish larvae.

Uptake and processing of a Vibrio anguillarum bacterin in Artemia franciscana measured by ELISA and immunohistochemistry.

Nauplii of Artemia franciscana were incubated in two different concentrations (undiluted and 1:9 in autoclaved sea water) of a divalent bacterin composed of two different serovars of Vibrio anguillarum. In order to investigate uptake and further processing of a bacterin in the live feed organism A. franciscana, immunohistochemistry was applied, visualising the presence of whole bacterial cells and antigens from the bacterin in individual nauplii. By using ELISA, it was shown that approximately 1.5-2-5 x 10(5) cells were incorporated into each Artemia under the conditions used. Maximum incorporation of cells was measured after 30 min, whereas after 60 min there was a decline to levels of 0.9-1.6 x 10(5) cells per Artemia. Immediately after incubation in the bacterin solution, the nauplii were transferred to a culture of the alga Isochrysis galbana, in order to simulate transfer of the nauplii to rearing tanks for fish larvae. From the ELISA, it could be concluded that the incorporated bacterial cells were excreted from the Artemia nauplii rapidly, however a large variation among different nauplii could be visualised by immunohistochemistry.