What are AFB positive bacteria?

What are AFB positive bacteria?

If your AFB culture was positive, it means you have active TB or another type of AFB infection. The culture can identify which type of infection you have. Once you have been diagnosed, your provider may order a “susceptibility test” on your sample.

Which organisms can be positive on acid-fast stain?

Acid-fast staining (Figure 5-39) is used to screen for the presence of Mycobacterium, Nocardia, and Legionella species in body tissues and fluids. Some oocysts, such as Cryptosporidium, can be detected with the acid-fast stain.

What can cause a positive AFB?

A positive AFB smear resulting from other bacteria that may have a positive AFB smear, such as Nocardia, Actinomyces, Rhodococcus, Legionella micdadei or cysts of Cryptosporidium species (12, 13).

Which are acid-fast bacilli?

Mycobacteria are called acid-fast bacilli because they are rod-shaped bacteria (bacilli) that can be seen under the microscope following a staining procedure in which the bacteria retain the color of the stain after an acid wash (acid-fast).

Can sputum test detect TB?

Rapid sputum tests are used to diagnose tuberculosis (TB) when other tests show that a person probably has TB. Rapid sputum tests are also called nucleic acid amplification tests (NAATs). One of the best ways to diagnose TB is through a sputum culture.

What AFB means?

Acid- Fast Bacilli (AFB) smear and culture are two separate tests always performed together at the MSPHL, Tuberculosis (TB) Unit. AFB smear refers to the microscopic examination of a fluorochrome stain of a clinical specimen.

How accurate is AFB test?

RESULTS: Diagnostic accuracy of induced sputum AFB smear was found to be 92.85%, sensitivity 63.63%, specificity 97.26%, PPV 77.78% and NPV 95.67% (p-value <0.001)and that of BAL was found to be 86.90%, sensitivity 52.94%, specificity 95.52%, PPV 75% and NPV 88.89% (p-value <0.001).

What is the principle of acid fast bacilli?

The mycobacterial cell wall contains mycolic acids, which are fatty acids that contribute to the characteristic of “acid-fastness.” The principle of the AFB smear is based on the fact that mycolic acid in the cell wall of AFB render them resistant to decolorization with acid alcohol.

How do you collect Genexpert sputum?

Take a very deep breath and hold the air for 5 seconds. Slowly breathe out. Take another deep breath and cough hard until some sputum comes up into your mouth. Spit the sputum into the plastic cup.