In the present study the impact on gut microbiology and indigenous gut histology of Atlantic salmon (Salmo salar L.) was investigated following feeding of a control and a prebiotic (EWOS prebiosal ® ) diet and ex vivo exposure to saline or the probiotic bacterium Carnobacterium divergens.The results showed that ex vivo exposure of C. divergens at 10 8 CFU ml -1 did not cause cell damage to the intestine tract of Atlantic salmon.Furthermore, prior provision of dietary prebiotic elevated the ability of C. divergens to adhere to the epithelium or mucus layer in the proximal intestine, where culturable heterotrophic bacterial levels (which were identified as C. divergens) were elevated by 234% compared to the control.This effect was not apparent in the distal intestine.The ability of isolated carnobacteria from the ex vivo experiment to inhibit growth of two fish pathogenic bacteria (Yersinia rückeri and Aeromonas salmonicida ssp.salmonicida) was assessed.Extracellular products from all 11 of the isolated carnobacteria strains, plus the type strain Carnobacterium inhibens CCUG 31728, inhibited the in vitro growth of Y. rückeri.However, only extracellular products from C. divergens isolate 57 inhibited the growth of A. salmonicida ssp.salmonicida.
The workshop on Three Rs Approaches in the Production and Quality Control of Fish Vaccines aimed a) to identify animal tests currently stipulated for the production and quality control of fish vaccines and to highlight animal welfare concerns associated with these tests; b) to identify viable options to replace, reduce, and refine animal use for fish vaccine testing; and c) to discuss the way forward and set out how the Three Rs may be implemented without jeopardizing the quality of the vaccines. The workshop participants – experts from academia, regulatory authorities, a scientific animal welfare organization, and the fish vaccine industry – agreed that efforts should be undertaken to replace the vaccination-challenge batch potency testing with tests based on antigen quantification or antibody response tests. Regulatory requirements of questionable scientific value and relevance for the quality of fish vaccines, such as the re-testing of batches produced outside Europe, or the double-dose batch safety test, should be re-considered. As an immediate measure the design of the current animal tests should be evaluated and modified in the light of refinement and reduction, for example, the number of unprotected control fish in vaccination-challenge tests should be reduced to the minimum.
This study summarises the availability of fish vaccines in Chile in the period 1999-2003. Through a questionnaire survey, data on annual sales per product were obtained from seven pharmaceutical companies and data on the corresponding farmed salmonid population eligible for vaccination were obtained from Sernapesca. More than 20 vaccines for aquacultured fish were brought to the Chilean market during the study period. The estimated number of fish being immunized by immersion increased from 93 million to more than 200 million, whereas sales of fish vaccines for injection increased from 2,008 to 16,561 1, the latter amount corresponding to approx. 150 million doses. Estimated vaccine coverage in the susceptible species ranked from 37-84% for yersiniosis (ERM), from 51-17% for salmonid rickettsial septicaemia (SRS), and from 8-78% for infectious pancreatic necrosis (IPN). Vaccine coverage against bacterial kidney disease (BKD) remained below 5%. (C) 2007 Elsevier B.V All rights reserved.
The pre-smolt stage of the scale of adult Norwegian Atlantic salmon from four populations, encompassing both farmed and wild hatchery stocks, has been analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-HR-ICP-MS). The purpose of this study was to test for differences in elemental composition between stocks of Atlantic salmon that have lived in separate fresh water locations until the smoltification and natural run out or transportation to the sea-cages. The populations studied were from fish farms located at Bremanger and Sørfold, a cultivated stock from Mossa, and one wild local stock from the river Gaula. The following elements were included in the analytical protocol: Li, Mg, Ca, Cr, Mn, Fe, Zn, Sr, Ba, Pb, and U. Calcium was used as a natural internal standard. Classification of the analytical data is studied by multivariate statistical techniques such as principal component analysis (PCA). We have been able to delineate the population of Atlantic salmon ( Salmo salar L.) from Gaula and Mossa from the Bremanger and the Sørfold stock based on the ten elements analyzed. The Bremanger and Sørfold stocks were partially delineated. The differences in elemental composition in the scales, which makes the delineating of the four stocks possible, probably reflects geological differences in the bedrock at the four fresh water locations experienced by the salmon during the pre-smolt stage.
