Search results for " Anguilla"

European Sea Bass (Dicentrarchus labrax) immune status and disease resistance are impaired by arginine dietary supplementation

2015

Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A…

Differential involvement of mussel hemocyte sub-populations in the clearance of bacteria.

2008

Abstract Mussels are filter-feeders living in a bacteria-rich environment. We have previously found that numerous bacterial species are naturally present within the cell-free hemolymph, including several of the Vibrio genus, whereas the intra-cellular content of hemocytes was sterile. When bacteria were injected into the circulation of the mussel, the number of living intra-hemocyte bacteria dramatically increased in less than an hour, suggesting intense phagocytosis, then gradually decreased, with no viable bacteria remaining 12 h post-injection for Micrococcus lysodeikticus, 24 h for Vibrio splendidus and more than 48 h for V ibrio anguillarum. The total hemocyte count (THC) was dramatica…

Lysozyme gene expression and hemocyte behaviour in the Mediterranean mussel, Mytilus galloprovincialis, after injection of various bacteria or temper…

2008

The aim of the present study was to evaluate the expression of the Mytilus galloprovincialis lysozyme gene in different in vivo stress situations, including injection of bacteria Vibrio splendidus LGP32, Vibrio anguillarum or Micrococcus lysodeikticus, as well as heat shock at 30 C and cold stress at 5 C. Injection of V. splendidus LGP32 resulted in: (i) a general down-regulation of lysozyme gene expression, as quantified by Q-PCR; (ii) reduction in the number of circulating hemocytes; (iii) decrease in the percentage of circulating hemocytes expressing lysozyme mRNA which was now restricted to only small cells, as observed by ISH; and (iv) accumulation of hemocytes expressing lysozyme in t…

Specific expression of antimicrobial peptide and HSP70 genes in response to heat-shock and several bacterial challenges in mussels

2007

Abstract Defensin, mytilin and myticin are antimicrobial peptides (AMP) involved in mussel innate immunity. Their in vitro antibacterial activity is different according to the targeted bacterial species. To determine if this specificity is correlated to different regulations of gene expressions, adult mussels were challenged in vivo with either Vibrio splendidus LGP32, Vibrio anguillarum , Micrococcus lysodeikticus or by heat shock. RNAs were isolated from circulating hemocytes and AMP mRNAs were quantified by Q-PCR using 28S rRNA as housekeeping gene. In addition, HSP70 gene expression was also quantified as representing non-specific response to stress. In naive mussels, the three AMP mRNA…

Mucosal immunity response of European eel (Anguilla anguilla L.) after bacterial infections

2019

Vibrio vulnificus: from water to host

2017

Vibrio vulnificus is an aquatic pathogen autochthonous from temperate, tropical and subtropical ecosystems where it lives either as a sessile cell, forming biofilms or as a free-swimming cell. From these locations, the pathogen can occasionally infect humans and fish causing a disease named vibriosis. The most severe form of human and fish vibriosis is associated with the pathogen’s ability to spread from the infection site to the bloodstream and multiply, process known as invasion. Before invasion, the pathogen has to colonize the mucosal host surface, process that involves not only bacterial attachment/adhesion but also resistance to mucosal immunity, commensal microbiota (competitors) an…