Gram-Negative Bacteria

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A Gram-Negative Bacteria is a bacteria that does not respond to a Gram Test.



References

2009

  • (Wikipedia, 2009) ⇒ http://en.wikipedia.org/wiki/Gram-negative
    • Gram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol. [1] In a Gram stain test, a counterstain (commonly safranin) is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color. The test itself is useful in classifying two distinct types of bacteria based on the structural differences of their cell walls. On the other hand, Gram-positive bacteria will retain the crystal violet dye when washed in a decolorizing solution.

      Many species of Gram-negative bacteria are pathogenic, meaning that they can cause disease in a host organism. This pathogenic capability is usually associated with certain components of Gram-negative cell walls, in particular the lipopolysaccharide (also known as LPS or endotoxin) layer. [1] In humans, LPS triggers an innate immune response characterized by cytokine production and immune system activation. Inflammation is a common result of cytokine(from the greek cyto=cell,kinesis=movement) production, which can also produce host toxicity.