CSF culture is a test used to detect the presence of microorganisms (bacteria, viruses, and fungus) in the cerebrospinal fluid (CSF) causing infection. CSF is a clear fluid that circulates in the space surrounding the spinal cord.

The CSF protects the brain and spinal cord from injury and physical shocks, and carries products of neurosecretions (chemicals released by the neural tissue), chemicals in the cells, and chemical changes in the cells.

The CSF is usually obtained through a lumbar puncture (spinal tap).

The culture is done in the lab. The fluid is placed in special media and allowed to grow. The microbiologist checks it every day. If the cultures grow (a "positive culture"), the microorganisms are identified and antibiotic susceptibility is checked, allowing for the best choice of antibiotics.

Preparation is the same as for a lumbar puncture. You must sign a consent form. You must be prepared to remain in the hospital for at least the 6 to 8 hours that you must remain lying down.

The position may be uncomfortable, but you MUST remain in the curled position to avoid moving the needle and possibly injuring the spinal cord.

The scrub will feel cold and wet. The anesthetic will sting or burn when first injected. There will be a hard pressure sensation when the needle is inserted, and there is usually some brief pain when the needle goes through the meninges (membranes covering the spinal cord). This pain should stop in a few seconds. Overall, discomfort is minimal to moderate.

The entire procedure usually takes about 30 minutes, but may take longer. The actual pressure measurements and fluid collection only takes a few minutes.

The culture helps identify fungus, virus, or bacteria that are present.

No organism growth (negative) is normal.

If growth of fungus, virus, or bacteria occurs (a "positive culture"), this indicates meningitis or other infections. The culture will determine the type of organisms present in the CSF.

See also:

• Anthrax
• Aseptic meningitis
• Brucellosis
• Cryptococcosis
• Inhalation anthrax
• Meningitis gram negative
• Meningitis, cryptococcal
• Meningitis, H. influenza
• Meningitis, meningococcal
• Meningitis, pneumococcal
• Meningitis; staphylococcal
• Meningitis; tuberculous
• Myelomeningocele (children)

• Risks of lumbar puncture include:
  • Hypersensitivity (allergic) reaction to the anesthetic
  • Discomfort during the test
  • Headache after the test
  • CSF leak
  • Bleeding into the spinal canal
• Brain herniation (if performed on a person with increased intracranial pressure), sometimes resulting in brain damage and/or death
• Damage to the spinal cord (particularly if the person moves during the test)

Not applicable.