Related Experiment Video
Updated: Feb 11, 2026

Identification of Fatty Acids in Bacillus cereus
Published on: December 5, 2016
A Tuberculosis-associated Endobronchial Polyp That Was Negative for Acid-fast Bacillus
1Department of Internal Medicine, Daegu Catholic University Medical Center, Korea.
Abstract:
The author reports the case of a patient with a tuberculosis-associated endobronchial inflammatory polyp. Acid-fast bacillus (AFB) staining and culturing of sputum and bronchial washing fluid specimens were negative on three occasions. Biopsy results twice showed chronic inflammation. The patient was finally diagnosed with Mycobacterium tuberculosis based on a polymerase chain reaction (PCR) of a biopsy tissue specimen, along with the finding of chronic granulomatous inflammation. The author herein reports a rare case of a tuberculosis-associated endobronchial inflammatory polyp that was AFB smear- and culture-negative and the patient's clinical course after treatment.
Related Concept Videos
Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
Negative Regulator Molecules
Positive, Negative, and Zero Work
Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Pulmonary Tuberculosis II
Here is a detailed explanation of its pathophysiology:
Transmission: The process begins when a person inhales droplet nuclei containing M. tuberculosis. These are typically released into the air when an individual with pulmonary or...
Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...

