Genomic diversity of Erysipelothrix rhusiopathiae isolated from UK swine

Erysipelas, caused by the bacterium Erysipelothrix rhusiopathiae, is re-emerging in swine and poultry production systems worldwide. While the global genomic diversity of this species has been characterized, how much of this genomic and functional diversity is maintained at smaller scales is unclear. Specifically, while several key immunogenic surface proteins have been identified for E. rhusiopathiae, little is known about their presence among field strains and their divergence from vaccines, which could result in vaccine failure. In this study, we use a comparative genomics approach to determine the diversity of E. rhusiopathiae strains in UK swine over nearly three decades. A specific aim was to determine the presence/absence and variability of thirteen previously described immunogenic surface proteins, including SpaA which is considered a key immunogen. A secondary aim was to assess the field strains' divergence from a vaccine strain commonly used in UK swine.