Enterobacter aerogenes and Aeromonas hydrophila encystment process of Acanthamoeba castellanii and recovery from mature cysts. Assays were performed to determine bacterial survival inside A. castellanii during encystment and their recovery from mature cysts as described in “Methods”. (A) represents ratio of bacteria per amoeba, while (B) represents bacteria associated with amoeba (% of the original inoculum). Results are represented as the mean ± standard error of three independent experiments performed in duplicate. (C) representative micrograph of A. castellanii cysts containing Escehrichia coli K1, Enterobacter aerogenes and Aeromonas hydrophila. Images were taken using light microscopy under different magnifications (200×, 400×, 1000×). Arrows indicate bacteria.