Specimen Collection
Proper patient specimen collection to isolate medically important anaerobic bacteria includes several important steps. According to Nagy et al., the following items are of the utmost importance:4
- Collection of the specimen before antibiotics are administered.
- Deep aspiration of pus/fluid or biopsy at the site of infection, far from heavily contaminated areas (and not pus or superficial swab collection at the superficial edge of the wound).
- Submission of aspirates and tissue specimens, rather than swabs. If a swab must be used, a swab made of synthetic fibers (and not cotton) is preferred.
- A collection free from contamination with normal bacterial flora is necessary, meaning the site should be debrided and decontaminated before specimen collection.
- Submission of the specimen in anaerobic transport media (ATM) using pre-reduced and anaerobically sterilized (PRAS) anaerobic media is preferable. Alternatively, Stuart's, Cary-Blair, or Amies transport media can be used, but the specimen must be deeply inserted into the transport device to avoid an oxygen interface.
Transport- Store and transport at room temperature. Do not refrigerate.
- Send to the laboratory within 2 hours of collection. Specimens may be accepted up to 48 hours post-collection if necessary. The ATM is required; if no ATM is available, a large volume of aspirate may be placed into a sterile container and transport to the laboratory must be prompt and within 1 hour of collection.
4. Nagy E, Boyanova L, Justesen US; ESCMID Study Group of Anaerobic Infections. How to isolate, identify and determine antimicrobial susceptibility of anaerobic bacteria in routine laboratories. Clin Microbiol Infect. 2018;24(11):1139-1148. doi:10.1016/j.cmi.2018.02.008.
