What is the significance of the presence of acid-fast bacteria in the sputum of a patient?

What is the significance of the presence of acid-fast bacteria in the sputum of a patient?

Sputum, or phlegm, is often used to test for Mycobacterium tuberculosis, to find out if a patient has TB. This bacterium is completely acid-fast, which means the entire cell holds onto the dye. A positive test result from the acid-fast stain confirms the patient has TB.

What happens if sputum AFB is positive?

If your AFB smear was positive, it means you probably have TB or other infection, but an AFB culture is needed confirm the diagnosis. Culture results can take several weeks, so your provider may decide to treat your infection in the meantime.

What does sputum for AFB mean?

A sputum stain for Mycobacteria is a laboratory test performed on a sample of your sputum, or phlegm. It’s also known as an acid-fast bacillus (AFB) stain or a tuberculosis (TB) smear. A doctor typically orders the test to determine if a person has tuberculosis (TB) or another type of mycobacterial infection.

What is the importance of AFB staining?

The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body substance is infected with the bacteria that causes tuberculosis (TB) and other illnesses.

Is AFB positive contagious?

A positive AFB smear or culture several weeks after drug treatment has started may mean that the treatment regimen is not effective and needs to be changed. It also means that the person is still likely to be infectious and can pass the mycobacteria to others through coughing or sneezing.

What does a positive sputum test mean?

A sputum culture is a test to find germs (such as TB bacteria) that can cause an infection. A sample of sputum is added to a substance that promotes the growth of bacteria. If no bacteria grow, the culture is negative. If bacteria grow, the culture is positive. If TB bacteria grow, then the person has tuberculosis.

Why is carbol Fuchsin used in acid fast staining?

It is commonly used in the staining of mycobacteria as it has an affinity for the mycolic acids found in their cell membranes. Carbol fuchsin is used as the primary stain dye to detect acid-fast bacteria because it is more soluble in the cells wall lipids than in the acid alcohol.

Why is the acid-fast stain a useful procedure when trying to diagnose an infection?

Acid fast stains are used to differentiate acid fast organisms such mycobacteria. Acid fast bacteria have a high content of mycolic acids in their cell walls. Acid fast bacteria will be red, while nonacid fast bacteria will stain blue/green with the counterstain with the Kinyoun stain.

How are sputum specimens used to diagnose tuberculosis?

Each sputum specimen was divided into 2 for the TB study (AFB smear and M. tuberculosisculture) and Gram staining. According to the Gram staining results, the specimens were graded using the Murray and Washington’s system. Sputum specimens of grade 4 or 5 were considered acceptable for diagnosing bacterial pneumonia (1, 7, 8, 9).

What does a positive AFB smear mean for TB?

If your AFB smear was positive, it means you probably have TB or other infection, but an AFB culture is needed confirm the diagnosis. Culture results can take several weeks, so your provider may decide to treat your infection in the meantime.

What kind of smear is used for AFB culture?

AFB smear performed using fluorescence microscopy. No smear is performed on blood, bone marrow, stool and urine specimens. Culture performed using 1 liquid (MGIT) and 3 solid (LJ and 7H11 bi-plate) media.

What do you need to know about sputum collection?

According to the pulmonary tuberculosis (TB) guidelines, patients require instructions regarding the proper method of sputum collection (3). Patients need to be informed that a desired sputum specimen consists of material brought up from the lungs after a productive cough and not nasopharyngeal discharge or saliva.