Validation of an equine arteritis virus antibody cELISA according to OIE protocol

commonly expressed in both strains. Surprisingly, those genes demonstrated a positive correlation (r21⁄40.81; p < 0.05), indicating the involvement of gene silencing (switching off) mechanisms to attenuate virulence of the pathogenic strain through cell passages. The results were validated by RT-qPCR using a set of 10 selected genes. This study is the first report characterizing the transcriptional profile of L. intracellularis. Specific properties of genes expressed at high levels in both or exclusively in the pathogenic strain may now be studied in order to: (i) understand the pathogenesis of PE; (ii) develop new diagnostic tools and (iii) develop recombinant vaccines. We believe the results support our hypothesis and open a new research field for studying target genes involved in the pathogenesis of PE. Figure 1. Schematic representation of the L. intracellularis genomes showing the distribution of genes expressed by the pathogenic (black circles) and the non-pathogenic (gray circles) variants. Overlapping zones represent genes expressed in both variants.