gram-positive or Gram-positive (grām'pŏz'ĭ-tĭv)
Of, relating to, or being a bacterium that retains the violet stain used in Gram's method.
Relating to a group of bacteria that turn a dark-blue color when subjected to a laboratory staining method known as Gram's method. Gram-positive bacteria have relatively thick cell walls and are generally sensitive to the destructive effects of antibiotics or the actions of the body's immune cells. Gram-positive bacteria include beneficial nitrogen-fixing bacteria in soil, as well as the bacteria that cause anthrax, botulism, leprosy, tuberculosis, scarlet fever, and strep throat. Compare gram-negative.