Antibacterial activity of mastic gum as an excipient for bacitracin compared to mastic gum alone and to bacitracin ointment
Clark J Baker, Jordan M Battaglia, Alex S BattagliaObjective:
Topical antibiotic and petrolatum ointments are commonly applied to surgical wounds to reduce surgical site infections (SSIs). However, their use may compromise adhesion of sterile dressings, increasing the risk of dressing displacement and wound contamination during postoperative care. A novel antibiotic-inoculated mastic gum adhesive was investigated for its ability to simultaneously offer antimicrobial prophylaxis and secure dressing fixation at the wound–skin interface.
Method:
Mastic gum adhesive (MG; acting as control), bacitracin ointment (BO) alone, and mastic gum adhesive combined with bacitracin (MG+B) were evaluated using a synthetic surgical wound model designed to simulate dressing-related contamination. Following bacterial exposure, cultures were collected from contaminated dressings or from agar plates positioned beneath the skin substrates to assess breakthrough contamination.
Results:
Bacterial contamination of synthetic wounds occurred in 28/30 (93%) MG control replicates, 14/24 (58%) BO replicates, and only 1/30 (3%) MG+B replicates. MG+B had significantly lower wound contamination rates compared with MG (p<0.001), BO (p<0.001) and ethanol (p <0.001). MG reduced bacterial growth by 1.19 log 10 reduction (p=0.002 versus control), but MG+B showed a stronger inhibition of 3.19 log 10 reduction (p=0.002 versus control; p<0.001 versus MG).
Conclusion:
MG+B combines the antimicrobial benefits of topical antibiotic ointments with the secure fixation of liquid adhesives. Results of this study indicated a statistically significant lower rate of bacterial breakthrough after contamination for MG+B compared to MG alone and to BO, warranting further investigation into MG+B as a strategy to reduce dressing-related contamination and SSI burden in clinical practice.