Taylorella equigenitalis and T. asinigenitalis persist within A. castellanii over time. Evolution of extracellular (A) and amoeba-associated (B) bacterial concentrations following co-cultures with A. castellanii of T. equigenitalis, T. asinigenitalis, E. coli or L. pneumophila. Amoebae were infected at an MOI of 50 and at indicated time, extracellular and amoeba-associated bacteria following lysis were quantified by plating. The results are expressed in CFU/ml and each bar represents the geometric mean of triplicate wells. The standard deviations are represented by error bars.