Fluids and Tissues Culture

Microbiology

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Test Usage

Determination of infection.

Specimen

Fluids & Tissues

Specimen container

20ml white top universal

Pink top EDTA tube for cell count (Joint Aspirates, Ascitc Fluid, CAPD Fluid ONLY)

BACTEC bottles for Sterile fluids (Joint Aspirates, Ascitc Fluid, CAPD Fluid ONLY)

To Request On EPIC

For electronic requesting using EPIC (RDUH ONLY):

For Synovial fluid ONLY:

Search for: ‘Synovial Fluid MC&S‘ or test code ‘LAB9388‘

For all other fluids (except Pleural fluid):

Search for: ‘Body fluid MC&S‘ or test code ‘LAB269‘

(For Pleural fluids see Respiratory Culture)

For tissue samples:

Search for: ‘Tissue/Bone MC&S’ or test code ‘LAB9394’

Specimen Collection

Transfer material to a universal container under aseptic conditions.

Special Instructions

Please list antibiotic therapy.

Is there any suspicion of Mycobacteria infection?  If yes please contact Microbiologist.

Bile, Drain Fluids & Breast Milk should not be repeated under 48 hrs.

Availability

Processed locally in Microbiology at RDUH

Processing Time

• Negative direct culture results are routinely reported within 48hrs, with the anaerobic incubation continuing for 5 days.
• Positives direct culture results are routinely reported within 72hrs.
• Negative enrichment culture is reported at 7 days.
• Orthopaedic extended culture is reported after 15 days incubation (5 days enrichment followed by 10 days FHB incubation.
• Cultures for extended fungal culture are typically reported at 7 days.

Urgent Specimen Instructions

Microscopy available on the day. Please contact the laboratory if this is required urgently.

Clinical Decision Values

Synovial Fluid

In the native non-rheumatoid joint, a synovial white cell count >50,000 x 10⁶/L gives a high probability of septic arthritis.

In a prosthetic joint, a synovial white cell count of >1700 x 10⁶/L is highly suggestive of chronic periprosthetic infection.

There are no recommended reference ranges for the diagnosis of acute prosthetic joint infection.

Ascitic Fluids

In spontaneous peritonitis, the polymorphonuclear leukocyte cell count is >250 x 10⁶/L.

Peritoneal Diasylate

In CAPD patients, an effluent cell count of >100 x 10⁶/L indicates the presence of inflammation, with infectious peritonitis being the most likely cause.

 

Specimen Labelling Procedure