Two unidentified men gaze on the bacteria billboard. (FLIKR USER THE MKT )

To promote the film, Warner Bros. Canada embraced the film’s theme and created two small billboards made entirely from bacteria.

(Read Michael O’Suliivan’s review for The Post here.)

A YouTube video shows the process in which “two large Petri dishes were inoculated with live bacteria including penicillin, mold and pigmented bacteria.” The result is the most amazing, creepy and literal viral marketing campaign in recent history.

“Contagion” opens Sept. 9.