Cerebrospinal Fluid (CSF) Culture Anaerobic
Cerebrospinal Fluid (CSF) Culture
Synonyms
Anaerobic Culture, Cerebrospinal Fluid
What the Test Includes
This test involves culturing cerebrospinal fluid (CSF) or fluid aspirated from intracranial lesions under anaerobic conditions to isolate and identify anaerobic bacteria.
Patient Preparation
Aseptic technique must be used to prepare the aspiration or lumbar puncture site. Avoid any skin flora contamination during collection.
Specimen Requirements
- Type: Cerebrospinal fluid or aspirate from intracranial lesions
- Container: Sterile CSF collection tubes
Collection Guidelines
- Label tubes as 1, 2, and 3 in the order collected
- The third tube is preferred for culture to avoid skin flora contamination
- Collect using lumbar puncture or lesion aspiration only when clearly indicated
Storage Instructions
Transport immediately under anaerobic conditions. Do not refrigerate. If delayed, store at room temperature or in an incubator.
Reasons for Sample Rejection
- Improper labeling
- Refrigerated specimens
- Inadequate anaerobic transport
Turnaround Time
- Preliminary negative report: after 3 days
- Full report: may take up to 2 weeks depending on isolated organisms
Special Instructions
Include details like exact specimen source, patient age, current antibiotic dosage, and clinical diagnosis. Use anaerobic transport medium when possible.
Clinical Use
Indicated only when anaerobic CNS infection is suspected, especially in cases of:
- Brain abscess
- Subdural or epidural empyema
- Suspected hematogenous spread from otitis media, sinusitis, or dental infections
Limitations
CSF is rarely the ideal sample for anaerobic cultures unless associated with direct intracranial lesions. Refrigeration can kill important pathogens such as Neisseria meningitidis and Haemophilus influenzae.
Methodology
- Solid and broth media under strict anaerobic conditions
- Prolonged incubation may be required for some anaerobes
Additional Information
Polymicrobial infections are common in cerebral abscesses. Common predisposing conditions include:
- Otitis media
- Sinusitis
- Dental infections
- Congenital heart disease
References
- Bartlett JG, Principles and Practice of Infectious Diseases, 3rd ed., Churchill Livingstone, 1990
- Gray LD, Fedorko DP, Clin Microbiol Rev, 1992
- Mathisen GE et al., Rev Infect Dis, 1984
- Jacobs, Demott, Finley, et al., Laboratory Test Handbook, Lexi-Comp Inc, 1994
