Pan-genome analysis of the complete genomes of A. baumannii. Panel A demonstrates the pan genome size of A. baumannii as calculated based on the power regression model. The plot shows an open pan-genome that predicts the total genome space to contain ~ 6500 genes. Panel B shows the rate of identification of new genes in each genome is approximately 66 genes per new genome at extinction. These values are based only on the complete genomes as it is difficult to predict complete genome size from incomplete genome data.