Proper collection and transport of biological specimen to the laboratory for culture is the most important step in the recovery of pathogenic organisms responsible for infectious disease. A poorly collected specimen may lead to failure to recover the causative organism(s) and/or result in the recovery of contaminating organisms. This will lead to incorrect or even harmful therapy if treatment is directed toward commensal or contaminant organisms.
The following are fundamentals to be considered when collecting microbiology specimens for culture:
- Collect the specimen from the actual site of infection, avoiding contamination from adjacent tissues, organs or secretions
- Collect the specimen at optimal times (for example, early morning sputum for AFB culture) to provide the best chance of recovering causative microorganisms.
- Whenever possible, collect specimens prior to administration of antimicrobial agents.
- A sufficient quantity of material must be obtained to perform the test.
- Properly label the specimen and complete the test request form. The specific source of specimen is required. Each culture container must be have a legible label, with the following minimum information:
- Patient name
- Patient identification number
- Source of specimen
- Name of clinician
- Date/hour of collection
- To ensure optimal recovery of microorganisms:
- Use appropriate collection devices: sterile, leak-proof specimen containers.
- Use appropriate transport media (anaerobe transport vials, Cary-Blair for stool culture, M4RT for viral and Chlamydia cultures, and urine boric acid transport).
- Use appropriate culture media
- Minimize transport time. Maintain an appropriate environment between collection of specimens and delivery to the laboratory.
- For the orders with more than one test, ensure that the proper transport system is utilized. (For example, anaerobic culture requests need to be submitted in anaerobic transport media; bacteriology requests should not be in viral media; AFB requests should not be in anaerobic transport media.)