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Cerebrospinal fluid Culture + Body Fluid Culture. 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. Specimen processing. Media : 2 Blood Agar Chocolate Agar
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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.
Specimen processing • Media : • 2 Blood Agar • Chocolate Agar • MacConkey Agar • Fluid Thioglycollate
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.
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.
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
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.
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 ).
Patient preparing • 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.
Specimen collection • Contamination with normal flora from skin, rectum, vaginal tract, or other body surfaces should be avoided. • Indicate the specific source and pertinent clinical history on the request form. • Body fluids should be treated as CSF specimens and should processed immediately.
Specimen processing • Media • Blood Agar (2 plates) • Chocolate Agar, • MacConkey Agar • Thioglycollate broth
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.