Surgical site infections and the microbiome: An updated perspective

To address 3 questions: What are the origins of bacteria causing surgical site infections (SSIs)? Is there evidence that the offending bacteria are present at the incision site when surgery begins? What are the estimates of the proportion of SSIs that can be prevented with perioperative control of the microbiome?

Review of the literature, examining recognized sources of bacteria causing surgical site infections.

Specifically, I examined the impact of improved control of the microbiome of the skin and nares on reducing SSIs. The initial effort was to examine the reduction of SSIs linked solely to preoperative skin preparation regimens and to either topical nasal antibiotics or pre- and postoperative nasal antiseptic regimens. To corroborate the concept of the importance of the microbiome, a review of studies showing the relationship of SSIs and marker organisms (eg, Propionobacterium acnes) present at the incision sites was performed. The relationships of SSIs to the microbiome of the skin and nares were summarized.

Depending on key assumptions, ∼70%-95% of all SSIs arise from the microbiome of the patients' skin or nares. Data from the studies of marker organisms suggest that the infecting bacteria are present at the incision site at the time of surgery.

Almost all SSIs arise from the patient's microbiome. The occurrence of SSIs can be viewed as a perioperative failure to control the microbiome.