Laboratory: Clinical Microbiology
Test Name:
Test Code: TISS, FLU, ORTH (SBH only)
Clinical Information:
Test Indications:
Aerobic bacterial culture of aseptically collected fluid or tissue obtained from a normally sterile site is used to help determine whether there is infection at the site, and the pathogen(s) involved.  Susceptibility testing performed on recovered pathogens can help guide therapy.

When possible, send fluid (aspirate) or tissue rather than a swab.  The volume of specimen obtained using a swab as the collection device is suboptimal.  Do not send a swab dipped in fluid.
Clearly indicate on the microbiology requisition the specimen site, the specimen type, and the test(s) requested (e.g., Bacterial culture - aerobic, Bacterial Culture - anaerobic, Yeast culture, Moulds and systemic mycoses, Mycobacterial culture).  When swabs are used as the collection device, a separate swab must be submitted for each test request.  Do not request tests that are not indicated based on the clinical presentation of the patient.  Refer to the LIM entries on mycobacterial culture, and fungal culture for further details pertaining to these pathogen types.
The laboratory will automatically perform a Gram stain when appropriate.  This does not need to be requested on the microbiology requisition.
Indicate the current antimicrobial therapy the patient is receiving on the requisition.
If molecular detection of bacteria (16S rRNA PCR and sequencing) directly from the sample is requested, please page the microbiologist on-call for approval.  It is best to do this at the time of specimen collection.
If there is clinical suspicion of a level 3 pathogen causing infection (e.g., Brucella, Francisella), please notify the laboratory at the time of specimen collection.

Patient Preparation Instructions:
The sample must be obtained using aseptic technique.  Follow protocols outlined by your healthcare facility for this sample type.
Accurate patient identification must be made prior to sample collection.  Patient identification should be done in accordance with site policy.
Samples and requisitions must be labeled/completed in accordance with the Shared Health Specimen Acceptance Policy.
Collection Devices:
Specimens collected with a swab are not optimal.  Every effort should be made to send fluid or tissue to the microbiology laboratory, rather than a small amount of sample on a swab.  For fluid samples/aspirates, do not transport the specimen in a syringe with a needle attached.
Specimen Required: Fluid or tissue obtained from a normally sterile site.  This includes all aseptically collected fluids (e.g., abdominal, amniotic, ascites, bile, joint, paracentesis, pericardial, peritoneal, pleural, synovial, and continuous ambulatory peritoneal dialysis [CAPD] fluid) and aseptically collected tissue/biopsy specimens.
Tissue - no minimum volume (Adult and Pediatric)
Fluid:  ≥1 mL (Bacterial culture - aerobic) (Adult and Pediatric)
Swab:  one swab (Bacterial culture - aerobic) - if additional tests are requested send one swab for each test. (Adult and Pediatric)
Larger volumes of specimen (fluid, tissue) will yield better results.  Always submit as much specimen as possible.
Where local protocol allows, a CAPD bag may be submitted to the laboratory for peritoneal dialysis fluid culture.
Never submit a swab that has simply been rubbed over the surface of tissue.
Reference Values:
A descriptive report will be sent.  Cultures will be incubated for up to 5 days before being reported as negative.
See Also:
More Information:
Specimen Handling:
Local: Transport as soon as possible, hold at room temperature.
Courier/local storage: ≤24 hours at room temperature.  Ensure samples that are being sent to a referral laboratory are packaged in accordance with Transport of Dangerous Goods recommendations for diagnostic samples.
For tissue samples, do not allow small samples/biopsies to dry out.

1.  Jorgensen JH, et al. (editors). Manual of Clinical Microbiology, 11th edition.