A pathogenic examination of virulent and avirulent aerococcus viridans var homari

Abstract

The American lobster (Homarus americanus) is the most successful commercial fishery in Canada. The industry creates 7800 jobs in the Atlantic region, making it a pivotal part of the local economy in rural Atlantic Canada. When lobsters are harvested, they are either sent directly to market, or kept in storage to ensure there is a supply of live lobster available for consumers year-round. The lobster fishery experiences periodic post-harvest loss due to an infection called gaffkemia. Gaffkemia is caused by the bacterium Aerococcus viridans var. homari. Large live lobster storage facilities have A. viridans screening procedures in place to limit post-harvest loss, but they are not sensitive enough to differentiate between naturally occurring virulent and avirulent strains. When a shipment tests positive for the bacterium, this creates a financial burden on the facility as they must treat the shipment and it must be sold at a lower value. This project hopes to characterize genomes of virulent and avirulent strains of A. viridans var. homari to identify the factors responsible for virulence in this bacterium. This project uses genomic approaches to identify variations in the genomes of virulent and avirulent strains of A. viridans var. homari. Genomic polymorphisms were compared between the phenotypes and putative virulence factors and impacted metabolic pathways were identified. No pathways had a significantly different number of polymorphisms between the phenotypes. However, the results of this study do indicate that particular regions of the genome are more prone to mutation than others.