- (of bacteria) retaining the violet dye when stained by Gram's method.
Origin of Gram-positive
First recorded in 1905–10; see origin at Gram's method
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for gram-positive
The Gram-positive bacteria are violet and the Gram-negative are red.
This method is excellent for differentiating Gram-positive and Gram-negative organisms on the same slide.
A Gram-positive stool due to cocci is suggestive of intestinal ulceration.A Manual of Clinical Diagnosis
James Campbell Todd
- designating bacteria that retain the violet stain in Gram's method
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- Of, relating to, or being a bacterium that retains the violet stain used in Gram's method.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.