Saprophytic mycobacteria are acid fast and do not cause serious disease.
M. tuberculosis has a cell wall that retains acid when you wash the slide with alcohol during the staining process.
The bacteria that causes tuberculosis is mycobacterium tuberculosis an acid fast bacteria
Tuberculosis is caused by an acid-fast bacteria called Mycobacterium tuberculosis.
AFB= Acid Fast Bacillus
Two acid-fast bacteria that are pathogenic are:1. Mycobacterium tuberculosis2. Mycobacterium avium- Microbioman
diseases in the Mycobacterium genus Tuberculosis, leprosy etc.
It is used for those bacteria which contain fat or lipid layer on their outer wall, and did not stain with grams staining. e.g. Mycobacterium
Some diseases are leprosy ( M. leprae), tuberculosis (M. tuberculosis), and nocardiosis ( N. brasiliensis, N. asteroides). The acid fast stain is important in identifying bacteria in the genus Mycobacterium and Nocardia.M. tuberculosis
NocardioformsNocardioforms include nine genera of aerobic, acid-fast rods, including members of the genus Nocardia. Nocardioforms have aerial hyphae which project above the surface of their growth medium as branching filaments. The hyphae fragment into rods and cocci. Nocardioforms are found throughout nature in many types of soil and aquatic environments. One species, N. asteroides, causes infection of the human lung.
Mycobacterium tuberculosis is an acid fast bacterium. It has a high concentration of mycolic acids in the plasma membrane which prevent its staining by typical Gram stain methods. It must be stained with a procedure containing an acid decolorizing step to best visualize it under the microscope (Ziehl Nielson or Kinyon Methods). It resists decolorization with the acid, which is where the term "Acid Fast" comes from....
Tuberculosis or TB is caused by acid fast bacteria (AFB) belonging to the genus Mycobacterium. In human TB is caused by Mycobacterium tuberculosis species and in cattles by Mycobacterium bovis. Both these species differ in only one aminoacid at position 57 (His in Mycobacterium bovis) which elicits difference in the response to the drug administered. This disease is treated using anti-tuberculosis drugs - rifampicin, isoniasid, ethambutol and pyrazinamide. In these drugs, pyrazinamide is a special drug in that it is the only available drug in the market with proven efficiency which acts on semi dormant bacteria. Other Mycobacterium species Mycobacterium leprae causes leprosy.
Acid fast rods seen in sputum are diagnostic of tuberculosis.
Primary stain: carbol fuchsin will leave the acid fast cells red, as it can penetrate the lipoidal (thick waxy) shell of the acid fast shell. Counterstain: methylene blue will leave the non-acid fast cells blue. So you should have red and blue.