A Pilot Study: Intraoperative 16S Rrna Sequencing Versus Culture in Predicting Colorectal Incisional Surgical Site Infection.

BackgroundSurgical Site Infection (SSI) of the abdominal incision is a dreaded complication following colorectal surgery. Identifying the intraoperative surgical site microbes may provide clarity in the pathogenesis of SSIs. Genomic sequencing has revolutionized the ability to identify microbes from clinical samples. Utilization of 16S rRNA amplicon sequencing to characterize the intraoperative surgical site may provide the critical information required to predict and prevent infection in colorectal surgery. MethodsThis is a pilot, prospective observational study of 50 patients undergoing elective colorectal resection. At completion of surgery, prior to skin closure, swabs were taken from the subcutaneous tissue of the abdominal incision to investigate the microbial profile. Dual swabs were taken to compare standard culture technique and 16S rRNA sequencing to establish if a microbial profile was associated with postoperative SSI. Results8/50 patients developed an SSI, which was more likely in those undergoing open surgery (5/15 33.3% versus 3/35, 8.6%; P = 0.029). 16S rRNA amplicon sequencing was more sensitive in microbial detection compared to traditional culture. Both culture and 16S rRNA demonstrated contamination of the surgical site, predominantly with anaerobes. Culture was not statistically predictive of infection. 16S rRNA amplicon sequencing was not statistically predictive of infection, however, it demonstrated patients with an SSI had an increased biodiversity (not significant) and a greater relative abundance (not significant) of pathogens such as Bacteroidacaea and Enterobacteriaceae within the intraoperative site. Conclusions16S rRNA amplicon sequencing has demonstrated a potential difference in the intraoperative microbial profile of those that develop an infection. These findings require validation through powered experiments to determine the overall clinical significance.