In addition, the Clinical Microbiology Procedures Handbook authors recommend the following:19
- Completely identify any anaerobe recovered from a blood culture. Exception: Possible skin contamination by Cutibacterium spp. as signified by only one of many bottles flagging positive.
- Always treat CSF as a sterile site and work up every organism. Exception: Be aware that growth in broth culture only may represent contamination.
- If swab workups are permitted, consider limiting to abbreviated identification(s). In many cases, swabs should be rejected, as mentioned in a prior topic section, depending on the collection and transport techniques used.
- If a large aspirate or body fluid is sent to the lab for workup, consider limiting to an abbreviated identification of the most typical pathogens when many mixed bacteria are present.
- Suspected Actinomyces spp.: Always hold culture plates and broth for 10 to 14 days before reporting as negative. (The body sites of interest would be jaw/mandible, neck abscess, and the like.)
- Suspected biofilm infection: Plan to hold cultures from infected prosthetic devices for 10 to 14 days before reporting as negative.
19. Leber A, Burnham CD, eds. Clinical Microbiology Procedures Handbook. 5th ed. Washington DC: ASM Press; 2023.
