Acid-fast bacteria

Definition

Acid-fast bacteria are a group of bacteria that resist decolorization by acids during staining procedures due to the high lipid content in their cell walls. They are primarily identified using the Ziehl-Neelsen stain or Kinyoun stain techniques.

5 Must Know Facts For Your Next Test

1. Acid-fast bacteria retain the primary stain (carbol fuchsin) even after treatment with acid-alcohol.
2. The most well-known acid-fast bacterium is Mycobacterium tuberculosis, which causes tuberculosis.
3. The Ziehl-Neelsen staining method uses heat to help the primary stain penetrate the waxy cell wall.
4. Kinyoun staining is a cold method that does not require heating but uses a stronger concentration of carbol fuchsin.
5. Acid-fast bacteria appear red or pink under a microscope, while non-acid-fast organisms take up the counterstain and appear blue.

Review Questions

Related terms

Ziehl-Neelsen Stain: A differential staining technique used for identifying acid-fast organisms using heat and carbol fuchsin.

Mycobacterium tuberculosis:

A species of pathogenic bacteria known as an acid-fast bacillus, which causes tuberculosis.

Kinyoun Stain: A modification of the Ziehl-Neelsen stain that does not require heating and uses a higher concentration of carbol fuchsin.