I am invisible, understand, simply because
people refuse to see me.         
                        Ralph Ellison, Invisible Man

      Clostridium difficile bacteria

Coloured transmission electron micrograph
of Clostridium difficile bacteria. These
Gram-positive rod-shaped bacteria can cause
pseudomembranous colitis (infection of the
colon), one of the most common hospital-
acquired infections, and antibiotic-associated
diarrhea. These disorders are often due to the
use of antibiotics, which kill off normal gut flora
and can lead to an overgrowth of C difficile.