Which of the following stains is also known as acid-fast stain?

UPRVUNL - 2021

Applied Microbiology & Infection control

Easy

Appeared in: UPRVUNL - 2021

Explanation

Ziehl-Neelsen (ZN) staining is the classic and most widely known method referred to as the acid-fast stain.
This technique is specifically designed to identify acid-fast organisms, which have a high content of mycolic acid (a waxy lipid) in their cell walls.
The mycolic acid makes the bacteria resistant to decolorization by acid-alcohol after they have been stained with a primary dye like carbol fuchsin.
As a result, acid-fast bacteria, such as Mycobacterium tuberculosis, retain the primary stain and appear bright red or pink, while non-acid-fast bacteria are counterstained (usually blue).

Option A: Albert stain is not an acid-fast stain. It is a special differential stain used to visualize metachromatic granules (volutin or polyphosphate granules) within the cells of Corynebacterium diphtheriae, the bacterium that causes diphtheria.
Option B: There is no standard microbiological staining procedure known as 'Lister stain'. Joseph Lister was a pioneer of antiseptic surgery, but a specific stain is not named after him in common laboratory practice.
Option C: Similar to Lister stain, there is no standard microbiological stain called 'Pasteur stain'. Louis Pasteur made foundational contributions to microbiology and vaccination, but a staining technique is not commonly named after him.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Microbiological Staining Techniques as background academic context rather than a clinical decision trigger.
The acid-fast stain is a cornerstone in the diagnosis of tuberculosis (TB), a major public health issue in India. A positive AFB smear provides a rapid, presumptive diagnosis, allowing for prompt initiation of treatment and isolation measures.
Nurses play a critical role in patient education for sputum collection. A high-quality sample (deep cough, early morning, mucoid/purulent) is essential for test accuracy. Poor samples can lead to false-negative results, delaying diagnosis and treatment.
What if? If a patient cannot produce sputum, the nurse may need to assist with or prepare the patient for alternative collection methods like sputum induction (using nebulized saline) or bronchoscopy, as ordered by the physician.

How to Approach the Question

This is a factual recall question that tests your knowledge of basic microbiology terminology.
First, identify the key term in the question: 'acid-fast stain'.
Next, analyze the options provided. The question asks for another name for the acid-fast stain.
Recall the different types of microbiological stains and their purposes.
Ziehl-Neelsen is the classic name associated with the hot method of acid-fast staining.
Eliminate the other options. Albert stain is for diphtheria granules, and Lister/Pasteur are distractors based on famous scientists' names.

Concept Tested & Keywords

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