Lab Dept:

Microbiology/Virology

Test Name:

CSF CULTURE AND GRAM STAIN

General Information

Lab Order Codes:

CSC

Synonyms:

Culture, CSF; Culture, Cerebrospinal Fluid; Culture, Lumbar Puncture; Culture, Reservoir Tap CSF; Culture, Shunt Fluid; Culture, Subdural Fluid; Culture, Ventricular Fluid; Culture, VP Shunt; Cerebrospinal Fluid Culture; Reservoir Top CSF Culture; Shunt Fluid Culture; Subdural Fluid Culture; Ventricular Fluid Culture; VP Shunt Culture

CPT Codes:

87070 – Culture, bacterial; any other source except urine, blood or stool, aerobic, with isolation and presumptive identification of isolates
87205 – Smear, primary source with interpretation; Gram or Giemsa stain for bacteria, fungi or cell types

The following testing may be added if appropriate based on the specimen submitted, findings for organism identification (multiple additions are possible if more than one organism is identified) and to aid in patient treatment management.

87015 – Concentration (any type), for infectious agents
87076 – Anaerobic isolate, additional methods required for definitive identification of isolates
87077 – Aerobic isolate, additional methods required for definitive identification, each isolate (if appropriate)
87106 – Culture, fungi, definitive identification, each organism, yeast (if appropriate)
87107 – Culture, mold, definitive identification, each organism, mold (if appropriate)
87206 – Smear, primary source with interpretation, fluorescent and/or acid fast stain for bacteria, fungi or cell types (if appropriate)
87184 – Susceptibility studies, disk method, per plate (if appropriate)
87185 – Enzyme detection (eg, beta lactamase), per enzyme (if appropriate)
87186 – Susceptibility studies, microdilution or agar dilution, each multi-antimicrobial, per plate (if appropriate)87076 – Anaerobic isolate, additional methods required for definitive identification of isolates

Test Includes:

Aerobic and anaerobic culture with isolation and identification of isolates. Susceptibility testing will be performed on significant isolates. All positive results are reported immediately by phone to the physician or patient’s nurse.

Logistics

Lab Testing Sections:

Microbiology

Phone Numbers:

Minneapolis:

Saint Paul:

612-813-5866

651-220-6555

Test Availability:

Daily, 24 hours

Turnaround Time:

Gram stain results are reported within 1 hour. Preliminary culture results are available at 24 hours. Negative cultures are final at 7 days.

Special Instructions:

● If only one tube of CSF is collected, submit to Microbiology first, otherwise submit tube #2. Tubes should be numbered 1, 2, 3, with tube #1 representing the first portion of the sample collected. Tube #2 or tube #3 are less likely to be contaminated by normal skin flora.
● Specimen site and date/time of collection are required for specimen processing.

Specimen

Specimen Type:

Cerebrospinal fluid

Container:

Sterile tube

Volume:

2 mL (Minimum 0.5 mL) CSF

Collection:

1. Disinfect skin site with 2% tincture of iodine.
2. Insert needle with stylet at L3–L4, L4–L5, or L5–S1 interspace.
3. Upon reaching the subarachnoid space, remove the stylet and collect 1–2 mL of fluid into each of 3 sterile CSF tubes.
4. Deliver tube #2 to Microbiology immediately.

Transport/Storage:

Transport to the Microbiology Laboratory immediately (<15 min) at room temperature and give to a technologist.

Special Processing:

Never refrigerate. If the specimen cannot be processed immediately, it should be kept at room temperature or placed in an incubator. Refrigeration may prevent the recovery of Neisseria meningitidis and Haemophilus influenzae.

Sample Rejection:

Specimen not submitted in appropriate transport container; improperly labeled specimen; insufficient volume. If an unacceptable specimen is received, the physician or nursing unit will be notified.

Interpretive

Reference Range:

No growth

Critical Values:

● Any bacterial isolate should be considered significant and evaluated clinically. All positive results will be called to the physician or patient’s nurse. Susceptibilities will be performed on significant isolates.
● Infection Prevention will be notified with gram stain results that appear to be gram-negative cocci/diplococci.

Limitations:

Cultures may be negative in partially treated cases of meningitis.

Methodology:

Culture of spun sediment

Additional Information:

Obtain blood culture as well. Blood cultures are often positive in patients with bacterial meningitis.

References:

Cook, JH, and M Pezzlo (1992). Specimen receipt and accessioning. Section 1. Aerobic bacteriology, 1.2.1-4. In HD Isenberg (ed) Clinical Microbiology Procedures Handbook. American Society for Microbiology, Washington DC

Miller, J Michael (1999) A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington DC

Miller, J Michael, and HT Holmes (1999) Specimen Collection, Transport, and Storage In PR Murray et al, (ed), Manual of Clinical Microbiology, 7^th edition, American Society for Microbiology, Washington DC, pp 33-104

Updates:

3/23/2010: CPT Updates
3/7/2011: CPT Updates
6/20/2012: Amended Critical Value statement