Pasteurella sp. - Pasteurellosis

Introduction

Bacteria belonging to the family Pasteurellaceae are the causative agents of pasteurellosis. High mortality by pasteurellosis has been reported in Norway since 2012. Mortality related to the outbreak of Pasteurella sp. occurs often 2-4 weeks after episodes that involve a lot of stress for the fish, such as vaccination, transport and exposure in the cage. Mortality can accumulate to high levels if the disease is not treated. VESO Aqualab offers challenge models with Pasteurella sp.

Challenge model to evaluate the efficacy of vaccination

Lumpfish are acclimatized for a minimum of two weeks before vaccination. After an immunization period of four weeks fish are challenged by i.p. injection or cohabitation. After challenge, mortality is recorded during an observation period of 2-4 weeks. Evaluation of the potency of the vaccine is based on differences in mortality in vaccinated and unvaccinated groups

Mortality in groups of unvaccinated lumpfish challenged with increasing doses of Pasteurella sp. by i.p. injection or cohabitation.