<i>T. cruzi</i> infectivity and ecto-ATPase/ADPase ratio decrease during in vitro cultivation.

<p>A) Ecto-ATPDase (solid bars) and Ecto-ADPDase (open bars) activities from live trypomastigotes from different cellular passages (P1, P3 and P4). P1-1 and P1-2 are the first and second massive exits of parasites from the 1^st passage; in the same way P3-1 and P3-2 are the first and second massive exits of parasites for the 3^rd passage. Data are mean±SE of triplicate assays from one experiment. The inset shows the ATPase/ADPase hydrolytic activities ratio. B) Microphotograph of infected VERO cells culture after 24 h of parasite-cell interaction at the 3^rd to 4^th passage. Spherical bodies are non-internalized amastigote-like parasites. C) Zoom from box section shown in B. Black arrow exemplifies a non-internalized amastigote-like and white arrow a non-internalized trypomastigote parasite.