Which staining method is used for staining of Mycobacterium tuberculosis?
Which staining method is used for staining of Mycobacterium tuberculosis?
Acid-Fast Bacteria—Ziehl– Neelsen Stain This stain is used to identify Mycobacterium tuberculosis, the causative agent of tuberculosis. Acid-fast organisms have a lipoid capsule that has a high molecular weight and is waxy at room temperature.
What is the role of Ziehl-Neelsen staining in the diagnosis of tuberculosis TB )?
Conventional smear microscopy with the Ziehl-Neelsen (ZN) stain is a rapid and practical method for detecting acid-fast bacilli (AFB), especially in low-income countries, due to its rapidity, low cost, and high positive predictive value for tuberculosis (14).
What Gram stain is Mycobacterium tuberculosis?
tuberculosis belongs to the high G+C Gram-positive bacteria that form a monophyletic group with the low G+C Gram-positive bacteria such as Bacillus subtilis.
What color is Mycobacterium tuberculosis?
The purple rod-shaped organism is a TB bacterium. This name, meaning ‘fungus-bacteria’ refers to shape of the bacillus when it grows in a laboratory: when seen through a microscope it forms heaps of small rods with protective layers around them, and thus looks like a fungus.
How does Ziehl-Neelsen stain work?
The Ziehl-Neelsen stain uses basic fuchsin and phenol compounds to stain the cell wall of Mycobacterium species. Mycobacterium does not bind readily to simple stains and therefore the use of heat along with carbol-fuschin and phenol allows penetration through the bacterial cell wall for visualization.
How are mycobacteria stained in the Hot ZN technique?
Mycobacteria, which do not stain well by Gram stain, are stained with carbol fuchsin combined with phenol. In the ‘ hot’ ZN technique, the phenol-carbol fuchsin stain is heated to enable the dye to penetrate the waxy mycobacterial cell wall.
What is the morphology of Mycobacterium tuberculosis?
Morphology of Mycobacterium tuberculosis. Straight or slightly curved thin rod-shaped bacilli. Non-sporing, non-motile, non-capsulated bacteria. Acid-fast bacilli, neither gram +ve nor gram –ve. During acid-fast stain, they appear bright red to intensive purple with green/blue background. They measure 0.5 µm x 3 µm.
What kind of stain is used for mycobacteria?
The Ziehl-Neelsen (ZN) method of the Acid Fast staining technique is used to stain Mycobacterium species, including M. tuberculosis, M. ulcerans and M. leprae, and non-tuberculous mycobacteria (NTM).
How does Ziehl-Neelsen method of staining mycobacteria work?
Principle of Ziehl-Neelsen method of acid-fast staining Mycobacteria, which do not stain well by Gram stain, are stained with carbol fuchsin combined with phenol. In the ‘ hot’ ZN technique, the phenol-carbol fuchsin stain is heated to enable the dye to penetrate the waxy mycobacterial cell wall.
