Yersinia pseudotuberculosis persists longer in association with A. castellanii than during monoculture. (A) Viable bacteria grown with A. castellanii, or grown singly. (B) Viable A. castellanii grown singly or in coculture with bacteria. Error bars indicate mean ± SD of at least three independent biological replicates. * = P < 0.01, ** = P < 0.001, *** = P < 0.0001. AC = A. castellanii, EC = E. coli DH5α, YPT = Y. pseudotuberculosis IP32953.