Cerebrospinal fluid Culture

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Cerebrospinal fluid Culture Body Fluid Culture
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Indications

• Mainly in Suspected cases of meningitis.
• See video

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Aim of the test

• Diagnosis of the bacteria or fungal meningitis by
  microscopic examination and culture with
  identification and susceptibility test of the
  isolated organism.

commensals
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Specimen collection

• Explain procedure to the patient and obtain
  written consent.
• See video

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• Quantity of specimen
• 3 ml of CSF is sufficient for culture.
• Time relapse before processing the sample
• CSF is an emergency specimen and should be
  processed immediately.
• Storage Room temperature
• The sample is submitted in 3 tubes chemistry,
  microscopic, culture sensitivity.

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Specimen processing

• Media
• Two Blood Agar
• Chocolate Agar
• MacConkey Agar
• Fluid Thioglycollate

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Culturing procedure

• As a general rule in CSF and body fluid specimens
  for culture
• Centrifuge clear specimen and inoculate plates
  and do staining from sediments.
• Turbid specimens may not be centrifuged.

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Result reporting

• Results of the microscopy and all positive
  cultures of CSF are reported immediately to the
  treating physician.
• Negative bacterial results are sent out 72 hours
  after the CSF is received.
• Examine all plates and broth medium for growth
  after 24 hrs.
• If no visible growth reincubate.
• Check all plate daily and discard after 7 days
  especially if gram stain was
• Generally ve culture indicate pathogens

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Turn around time

• Gram stain result is reported within 30 minutes
  of specimen receipt
• Positive Culture results 3- 5 days
• Negative Culture results 2-3 day

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Additional information

• Several antigen detection methods are available
  for capsular antigen of H. influenzae, N.
  meningitidis, S. pneumoniae and Group B
  streptococci in CSF which showed specificity and
  sensitivity of about 90-97.
• The routine culture for CSF does not include all
  organisms mentioned in the above table.

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• Finding bacteria does not necessarily mean the
  infection is contagious, unless it is
  meningococcal meningitis
• Viral we test mainly HSV and Enterovirus
• Fungal we test for Candida and Cryptococcus.

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Body Fluid Culture
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Body Fluid Culture

• This means
• Culture of Body Fluid such as peritoneal,
  pericardial, plural, ascitic, synovial.
• Aim of the test
• Isolate and identify pathogenic organisms from
  normally sterile body fluids and perform
  sensitivity test.
• Types of specimen
• Aseptically aspirated body fluid (e.g., synovial,
  peritoneal fluid, pericardial fluid, and pleural
  fluid ).

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Patient preparing

• Explain procedure to the patient and obtain
  written consent.
• Swab skin over the site of puncture with 2
  tincture of iodine in concentric circles.
• Iodine should remain in contact with skin for at
  least 1 minute prior to puncture to ensure
  complete antisepsis.
• Before puncture, 70 alcohol is used to remove
  iodine from skin.

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Specimen collection

• Contamination with normal microbiota from skin,
  rectum, vaginal tract, or other body surfaces
  should be avoided.
• Indicate the specific source and pertinent
  clinical history on the request form.
• See video

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• Quantity of specimen 1-5 mL is adequate.
• Time relapse before processing the sample
• Body fluids should be treated as CSF specimens
  and should processed immediately.
• Storage
• Maintain specimen at room temperature. Do not
  refrigerate.
• Media
• Blood Agar (2 plates)
• Chocolate Agar,
• MacConkey Agar
• Thioglycollate broth

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Specimen processing
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Result reporting

• Report Gram stain finding as an initial report.
• Report the isolated pathogen and its sensitivity
  pattern as a final report.
• Turn around time
• Gram stain and wet mount results should be
  available 1 hour after specimen receipt.
• Isolation of a possible pathogen can be expected
  after 2-3 days.
• Negative culture will be reported out 1-2 days
  after the receipt of the specimen.

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