gram-negative

gram-neg·a·tive or Gram-neg·a·tive (grmng-tv)

adj.

Of, relating to, or being a bacterium that does not retain the violet stain used in Gram's method.

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Gram-negative

adj

(Life Sciences & Allied Applications / Microbiology) designating bacteria that fail to retain the violet stain in Gram's method

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gram-negative

Relating to a group of bacteria that do not change color when subjected to the laboratory staining method known as Gram's method or Gram's stain. Gram-negative bacteria have relatively thin cell walls and are generally resistant to the effects of antibiotics or the actions of the body's immune cells. Gram-negative bacteria include E. coli and the bacteria that cause gonorrhea, typhoid fever, rickettsial fever, cholera, syphilis, plague, and Lyme disease. Compare gram-positive.

Thesaurus

Adj.

1.

Gram-negative - (of bacteria) being of or relating to a bacterium that does not retain the violet stain used in Gram's method bacteria, bacterium - (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants disconfirming, negative - not indicating the presence of microorganisms or disease or a specific condition; "the HIV test was negative"