Gram-positive

[ gram-poz-i-tiv ]

adjective

, (often lowercase)

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

Gram-positive

adjective

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

gram-positive

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.
2. Compare gram-negative

Word History and Origins

Origin of Gram-positive¹

First recorded in 1905–10; Gram's method

Example Sentences

A Gram-positive stool due to cocci is suggestive of intestinal ulceration.

From Project Gutenberg

The report was "moderate amount of pus cells, few gram positive cocci."

From Project Gutenberg

Smear, few pus cells, some mucus threads noted, occasional gram positive cocci noted.

From Project Gutenberg

The bacillar threads are in places Gram-negative, in others Gram-positive, and bear small club-like swellings (see Fig. 14).

From Project Gutenberg

The Gram-positive bacteria are violet and the Gram-negative are red.

From Project Gutenberg