Bone marrow culture

Definition

Bone marrow culture is a laboratory test performed on a bone marrow specimen to isolate and identify organisms that cause infection.

How the test is performed

A sample of bone marrow is placed on culture media in containers to grow microorganisms such as bacteria, fungus, or viruses in the laboratory. These "cultured" microorganisms will later be identified under the microscope.

The microbiologist in the laboratory inspects the cultures daily for growth of organisms. If microorganisms are detected, other tests may be performed to determine which drugs will kill the organisms. Definitive antimicrobial therapy can then be initiated based on these results.

How to prepare for the test

A bone marrow aspiration or biopsy is necessary to collect the specimen for the culture. This procedure is performed by a physician, usually a hematologist (blood specialist).

How the test will feel

The specimen is collected from the back of the pelvic bone or from the sternum. The area is cleansed with antibacterial soap. The skin over the bone is numbed with an anesthetic (a bee-sting sensation), then a larger needle is inserted through the skin into the bone and pushed into the cavity of the bone that contains the marrow.

A sample of bone marrow is aspirated into a syringe for analysis. Pressure and pain may occur with this procedure. Soreness at the site usually lasts from only hours to a day or two.

If a bone marrow biopsy is also performed, a larger hollow-core needle is inserted, and a core sample of bone marrow is removed. A portion of the sample can be examined (biopsy sample) and another portion can be sent for culture. A bone marrow biopsy may cause feelings of pressure or pain. The pain is minimized with anesthesia of the bone (local anesthetic injected near the bone).

Why the test is performed

The test may be performed when unexplained fever is present or if infection of the bone marrow is suspected.

Normal Values

No organism growth in the culture media is normal.

What abnormal results mean

Infection of the bone marrow is present. The infection may be bacterial, viral, or fungal.

What the risks are

The risks include bleeding and infection.

Special considerations

A bone marrow aspirate or biopsy specimen may be sent for many different types of tests, which may, with proper indications, increase costs considerably.

Illustrations

Bone marrow aspiration

Page Content:

Culture - bone marrow