CPT® Code 87118

A laboratory test known as culture for mycobacterial definitive identification is performed to isolate and accurately identify mycobacteria from various body fluid samples. Mycobacteria are a group of bacteria that are characterized as aerobic, non-motile, and acid-fast bacilli, which means they retain certain stains even after being washed with acid. This unique property is due to their thick, waxy, and hydrophobic cell wall, which poses challenges in both culturing the bacteria and treating infections caused by them. The procedure involves collecting fluid samples from different sources, including cerebrospinal fluid, gastric aspirate, respiratory secretions, bronchial washings or brushings, sputum, urine, or corneal wash. These samples are collected through separately reported procedures. Once collected, the fluid samples are placed in a specialized culture medium that supports the growth of mycobacteria. The culture is then incubated for a specified duration to allow the bacteria to proliferate. After sufficient growth, the cells are analyzed using advanced techniques such as Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry, which enables the definitive identification of specific mycobacterial species, including M. tuberculosis complex, M. avium complex, M. kansasii, and M. gordonae.