Distribution of ICT values obtained from the evaluated enrichment protocols shown as box-plot graphs. Each of the 10 box-plot represents summary statistics of the ICT values for a particular enrichment protocol and tonsil homogeneous mixture (Tonsil) for Y. enterocolitica (A) and Y. pseudotuberculosis (B). Boxes represented the 25% and 75% percentiles, the horizontal lines inside boxes indicate the ICT median values, the diamond shape represent the ICT mean and the vertical lines extended to the ICT minimum to maximum values. The number of samples studied in each enrichment protocol was 8 for Y. enterocolitica and 4 for Y. pseudotuberculosis. Attending to tonsil homogeneous mixture they were 4 for Y. enterocolitica and 2 for Y. pseudotuberculosis.