gram-positive

adjective (often lowercase)

1. (of bacteria) retaining the violet dye when stained by Gram’s method.

adjective

1. designating bacteria that retain the violet stain in Gram’s method

adj.

1. Of, relating to, or being a bacterium that retains the violet stain used in Gram’s method.

1. 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.