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• Gram-positive
  Gram-positive

  adjective

  (of bacteria) retaining the violet dye when stained by Gram's method.
• gram-positive
  gram-positive

  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.

Gram-positive

American  

[gram-poz-i-tiv] / ˈgræmˈpɒz ɪ tɪv /

adjective

(often lowercase)

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

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Gram-positive British  

adjective

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

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gram-positive Scientific  

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

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Etymology

Origin of Gram-positive

First recorded in 1905–10; see origin at Gram's method

Example Sentences

See Examples For:

Gram-positive gram-positive

She added that the drugs did not provide effective coverage against a Gram-positive organism, which was the most likely pathogen causing the infection.

From BBC ● Mar. 11, 2026

Gram-positive and gram-negative bacteria differ in the composition of their cell walls.

From Science Daily ● May 29, 2024

"We have pretty strong evidence that this new structural class is active against Gram-positive pathogens by selectively dissipating the proton motive force in bacteria," Wong says.

From Science Daily ● Dec. 21, 2023

One branch leads to the domain bacteria, which includes the phyla proteobacteria, chlamydias, spirochetes, cyanobacteria, and Gram-positive bacteria.

From Textbooks ● Jan. 1, 2015

In the early stages of incubation, at 100° to 112° F., the bacilli are uniform in size and intensely Gram-positive; in succeeding stages the irregular, vacuolated, inflated, and ruptured forms predominate.

From The Bacillus of Long Life a manual of the preparation and souring of milk for dietary purposes, together with and historical account of the use of fermente by Douglas, Loudon

Lolamicin had no detectable effect on gram-positive bacteria in cell culture.

From Science Daily ● May 29, 2024

The experimental dressing had excellent antibacterial performance against gram-negative and gram-positive bacterial species, and effectively eradicated E. coli and staph bacteria in testing.

From Science Daily ● Feb. 8, 2024

Others propose that they developed from gram-positive bacteria.

From Textbooks ● Jun. 9, 2022

Sodium bicarbonate secretions from the pancreas maintain the pH of the human intestine, where many beneficial methanogens are gram-positive bacteria.

From Textbooks ● Jun. 9, 2022

The protective value of both "gram-positive" and "gram-negative" destroyers has yet to be tried on human beings.

From Time Magazine Archive