RESUMEN
BACKGROUND: Reducing the rising health-care burden associated with shoulder surgical site infection (SSI) is of paramount importance. The purpose of this study was to investigate the antimicrobial efficacy of protocatechuic acid (PCA) as a topical reagent for surgical skin antisepsis surrounding the shoulder joint. METHODS: This was a 2-phase skin-disinfection trial involving the human shoulder. The shoulders of healthy volunteers were randomized to topical treatment with PCA (a 10% concentration of PCA in Phase I [11 subjects] and a 17% concentration in Phase II [12 subjects]), with a control of isopropyl alcohol (IPA) applied to the contralateral shoulder. Mechanical scraping was performed for skin harvest following reagent application, and samples were sent for aerobic and anaerobic culture. Sterilization rates and bacterial counts were determined for each treatment group, and the proportion of subjects with persistent Cutibacterium acnes colonization following topical application of PCA was determined using DNA sequencing analysis. RESULTS: The topical application of 10% PCA was associated with significantly higher aerobic and anaerobic sterilization rates (90.9% and 81.8%, respectively) compared with treatment with IPA (p = 0.0143 and p = 0.0253, respectively). The topical application of 17% PCA was associated with a significantly higher anaerobic sterilization rate (83.3%) and trended toward a significantly higher aerobic sterilization rate (91.7%) compared with treatment with IPA (p = 0.0143 and p = 0.083, respectively). C. acnes was identified in 18.2% and 0% of subjects following treatment with 10% and 17% PCA, respectively. CONCLUSIONS: The topical application of PCA was associated with a reduction in the bacterial burden of human shoulder skin and demonstrated dose-dependent antimicrobial activity against C. acnes in young, healthy subjects. Clinical studies in a shoulder surgical population are warranted to determine the potential for application in surgical skin antisepsis to reduce shoulder SSI. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
RESUMEN
BACKGROUND: There is a need for novel skin antiseptic agents to combat the health-care burdens associated with surgical site infection (SSI) and bacterial resistance. The purpose of this proof-of-principle pilot study was to investigate the potential of the phenolic compound protocatechuic acid (PCA) as a topical antimicrobial for surgical skin antisepsis. METHODS: The Kirby-Bauer method of disc diffusion was used to investigate the in vitro antimicrobial activity and comparative effectiveness of PCA and 7 related compounds against SSI pathogens. To explore the in vivo efficacy of topical PCA for providing deep, penetrating skin antisepsis, living Cutibacterium acnes was intradermally injected into the skin of female BALB/c mice. Mice were assigned to treatment with daily applications of topical PCA at 3 doses (78, 39, and 19.5 mM) or no treatment (n = 2 mice per group). After 96 hours, infected skin samples were harvested to compare mean C. acnes counts by treatment. RESULTS: Compared with other polyphenols, PCA demonstrated the broadest spectrum of antimicrobial activity against tested SSI pathogens, including drug-resistant organisms. At 96 hours following infection, the mean C. acnes burden in untreated mice was 6.65 log colony-forming units (CFUs) per gram of skin. Compared with the untreated group, daily topical application of 78 mM of PCA was associated with a significantly lower C. acnes CFU burden in mice skin (mean, 5.51 log CFUs per gram of skin; p = 0.0295). Both lower dosages of topical PCA failed to show an effect. CONCLUSIONS: PCA demonstrated laboratory efficacy against pathogens implicated in SSI, including drug-resistant organisms. In vivo, topical PCA demonstrated dose-dependent skin penetration and antimicrobial activity against mouse skin C. acnes loads. Human clinical studies exploring the antimicrobial efficacy of topical PCA for preoperative shoulder skin antisepsis are warranted. CLINICAL RELEVANCE: Topical PCA may have the potential to improve current shoulder SSI treatment and prevention protocols.
