What Is the Role of the Gut in Wound Infections?

Emerging evidence suggest a major role for the gut microbiome in wound infections. A Trojan Horse mechanism of surgical site infections has been hypothesized to occur when pathogens in the gut, gums, and periodontal areas enter an immune cell and silently travel to the wound site where they release their infectious payload. Genetic tracking of microbes at the strain level is now possible with genetic sequencing techniques and can clarify the origin of microbes that cause wound infections. An emerging field of dietary prehabilitation to modulate the microbiome before surgery is being described to improve infection-related outcomes from surgery.

Defeating Cancel Culture in Surgical Site Infection Research: A Plea to Include Microbial Cultures and Antibiotic Sensitivity Data.

Background: Despite advances in infection control measures, surgical site infections (SSIs) remain a real and present danger to patients. In most studies addressing SSI prevention measures, recommendations are often made in the absence of information such as culture results, the antibiotic agents used for prophylaxis, and antibiotic sensitivity data. The aim of this study is to document this latter claim by reviewing studies published in the last five years in highly read and cited surgical journals. Methods: A systematic review evaluating SSIs from four highly cited surgical journals, Annals of Surgery, the British Journal of Surgery, JAMA Surgery, and the Journal of the American College of Surgeons was conducted for articles published between 2016 and 2021. We focused our analysis on the following key features: how SSI is defined; bacterial culture information; antibiotic sensitivity data; and identification of the antibiotic chosen for prophylaxis. We hypothesized that, in most cases among the journals queried, this information would be unavailable. Results: Of the 71 studies included, 32 diagnosed SSIs based on criteria developed by the U.S. Centers for Disease Control and Prevention while five provided no definition of SSI. Of the 27 articles recommending increasing antibiotic usage, only one study performed antibiotic sensitivity testing to guide the antibiotic choice. Of 71 studies reviewed, only one reported all key features we considered to be important for SSI antibiotic decision-making; 46 reported none of the key features. Conclusions: Among publications addressing SSIs in four highly cited surgical journals, key information regarding diagnosis and with which to base antibiotic recommendations, is routinely unavailable.

A Novel Nonantibiotic Gut-directed Strategy to Prevent Surgical Site Infections.

OBJECTIVE: To determine the efficacy of an orally delivered phosphate-rich polymer, Pi-PEG, to prevent surgical site infection (SSI) in a mouse model of spontaneous wound infection involving gut-derived pathogens. BACKGROUND: Evidence suggests that pathogens originating from the gut microbiota can cause postoperative infection via a process by which they silently travel inside an immune cell and contaminate a remote operative site (Trojan Horse Hypothesis). Here, we hypothesize that Pi-PEG can prevent SSIs in a novel model of postoperative SSIs in mice. METHODS: Mice were fed either a standard chow diet (high fiber/low fat, SD) or a western-type diet (low fiber/high fat, WD), and exposed to antibiotics (oral clindamycin/intraperitoneal cefoxitin). Groups of mice had Pi-PEG added to their drinking water and SSI incidence was determined. Gross clinical infections wound cultures and amplicon sequence variant analysis of the intestinal contents and wound were assessed to determine the incidence and source of the developing SSI. RESULTS: In this model, consumption of a WD and exposure to antibiotics promoted the growth of SSI pathogens in the gut and their subsequent presence in the wound. Mice subjected to this model drinking water spiked with Pi-PEG were protected against SSIs via mechanisms involving modulation of the gut-wound microbiome. CONCLUSIONS: A nonantibiotic phosphate-rich polymer, Pi-PEG, added to the drinking water of mice prevents SSIs and may represent a more sustainable approach in lieu of the current trend of greater sterility and the use of more powerful and broader antibiotic coverage.