This is a photomicrograph of the organism that causes pneumococcal pneumonia. The bacterium is round, but join together to form pairs and chains. Because they typically join together to form pairs, they are called diplococci; the prefix di means two.
Review Date: 1/25/2013
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.