The Chilean aquaculture has been challenged for years by piscirickettsiosis. A common prophylactic measurement to try to reduce the impact from this disease is vaccination, but the development of vaccines that induce satisfactory protection of the fish in the field has so far not been successful. Experimental challenge models are used to test vaccine efficacy. The aim of this study was to evaluate the performance of experiment...

Piscirickettsiosis, caused by the intracellular Gram‐negative bacteria Piscirickettsia salmonis, is at present the most devastating disease in the Chilean salmon industry. The aim of this study was to analyse disease development after challenge with a P. salmonis strain (EM90‐like) under a controlled environment by comparing intraperitoneal challenge with cohabitation challenge. The P. salmonis EM90‐like isolate was cultured i...

Serious infectious diseases, accompanied by macrophage‐dominated chronic inflammation, are common in farmed Atlantic cod. To increase knowledge relating to morphological aspects of such inflammatory responses, cod were challenged with Francisella noatunensis , an important bacterial pathogen of this fish species. Tissue and cell dynamics in the spleen were examined sequentially over 60 days. Small clusters of mainly macrophage...