Mycobacterium species culture, Tissue, Qualitative

What This Test Does

The laboratory places a small piece of tissue in special culture media designed to support the growth of mycobacteria. Because these bacteria grow slowly, the culture may be watched for several weeks. If organisms grow, the lab identifies them and may perform additional testing to guide treatment.

Why Your Provider Ordered It

Your provider may order this test when there are signs of a chronic infection in a tissue, such as persistent inflammation, nodules, or granulomas seen on biopsy, or when tuberculosis or another mycobacterial infection is suspected in an organ or deep tissue. It can help confirm or rule out these infections.

How the Sample Is Collected

The sample is a piece of tissue, usually obtained during a biopsy or minor surgical procedure. Your care team will explain how to prepare, what to expect during collection, and any aftercare instructions.

What Results Mean

A positive culture means mycobacteria grew from the tissue, which supports a mycobacterial infection; the lab report usually names the species and may include drug-susceptibility results. A negative culture means no mycobacteria grew, but a single negative result does not always rule out infection, and your provider will interpret it alongside your symptoms, imaging, and other tests. No result should be interpreted without your clinician.