The Satan Bug (1965)

Director: John Sturges
Cast: Anne Francis, Dana Andrews, Ed Asner, Frank Sutton, George Maharis, John Larkin, Richard Basehart, Richard Bull

Synopsis:

A US government germ warfare lab has had an accident. The first theory is that one of the germs has been released and killed several scientists. The big fear is that a more virulent strain, named The Satan Bug because all life can be killed off by it should it escape, may have been stolen.