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See also: gram-positive


Alternative forms[edit]


From Gram (a surname) + positive, after Danish bacteriologist Hans Christian Gram, who invented the Gram staining method.


Gram-positive (not comparable)

  1. (bacteriology, of a bacterium) That stains dark blue or violet after Gram staining, due to large quantities of peptidoglycan in the cell wall.
    • 1997, T. G. Nagaraja, C. J. Newbold, C. J. Van Nevel, D. I. Demeyer, 13: Manipulation of ruminal fermentation, P. N. Hobson, C. S. Stewart (editors), The Rumen Microbial Ecosystem, 2nd Edition, page 545,
      Generally, ionophore antibiotics are highly effective against Gram-positive bacteria but exhibit little or no activity against Gram-negative bacteria (Chen and Wolin, 1979; Watanabe et al., 1981).
    • 2007, Alan R. Hauser, Antibiotic Basics for Clinicians: Choosing the Right Antibacterial Agent[1], page 201:
      Note that L.[Listeria] monocytogenes is one of the few Gram-positive bacteria against which vancomycin is not effective — hence the need for ampicillin.
    • 2011, Patricia L. Keen, Mark H. M. M. Montforts, Antimicrobial Resistance in the Environment, page 108,
      The majority of Gram-positive (82%) and Gram-negative (64%) genera carry either ribosomal protection genes alone or in combination with efflux/enzymatic genes as illustrated in Table 7.2.

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