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Gram-negative

Gram-negative

2 6.8
Bacteria that do not keep a purple Gram stain and often resist some antibiotics
  • adjective
  • /ˈɡræmˌnɛɡətɪv/
  • Specialized
: Gram-negativo
  • Endotoxin is a structural component found in the outer cell wall of Gram-negative bacteria.
  • Gram-negative bacteria
  • Gram-negative bacilli
  • Gram-negative rods

Examples

  • Endotoxin is a structural component found in the outer cell wall of Gram-negative bacteria.

  • In 7 of 8 VAP patients, gram-negative microorganisms were recovered via endotracheal aspirate.

    Academic text (2007)
  • The mortality caused by VAP increases if it is caused by gram-negative bacilli.

    Academic text (2007)
  • His main interests include the genetics and molecular epidemiology of resistance in gram-negative rod-shaped bacteria.

    Academic text (2015)
  • "A rise in vaginal pH typically indicates an overgrowth of gram-negative bacteria," says Dezzutti.

    Academic text (2014)
  • The predator cell invades and grows within a specific compartment found in Gram-negative cells, the periplasm.

    Academic text (2017)
  • LPS is a hallmark of Gram-negative bacteria and the ligand for Toll-like receptor 4 (TLR4).

    Academic text (2018)
  • Vibrio vulnificus is a motile, halophilic, rod-shaped gram-negative pathogen that lives in estuarine environments (1).

    Academic text (2015)
  • LPS is a hallmark of Gram-negative bacteria and plays a crucial role in immune response.

  • "A rise in vaginal pH typically indicates an overgrowth of Gram-negative bacteria," says Dezzutti.

Antonyms

Gram-positive
  • Specialized
1 6.7

Bacteria that keep a purple stain when scientists stain them in a lab because they have a thick cell wall

Surface Forms

Gram-negative positive
gram-negative positive

Morphology

Gram-negative = Gram + negative (semi-transparent) = Gram + negative

The combination 'Gram' + 'negative' is compositionally clear, but understanding the precise meaning requires knowledge of the Gram staining test in microbiology.

Etymology

Gram-negative is named after the scientist Gram, who made a simple staining test, and negative means 'not'. In that test these bacteria do not keep the violet dye, so 'Gram-negative' tells us they are 'not' stained, which explains the term's modern meaning.