683. Assessment of Biofilm Eradication and Cytotoxicity of a Novel Polygalacturonic Acid + Caprylic Acid Wound Ointment Compared with Antiseptic Wound Ointments

Background Antiseptic wound ointments are increasing importance from safety, microbiological and public health points of view. Previously, Rosenblatt et al. (2017) has assessed polygalacturonic acid (PG) + caprylic acid (CAP) solution for biofilm eradication efficacy and cytotoxicity. In this study, we assessed biofilm eradication and cytotoxicity of PG+CAP wound ointment compared with commercially available wound ointment comparators. Methods Assessment of antimicrobial efficacy was conducted using a well-established biofilm model. Twenty-four-hour biofilm was formed on silicone discs and exposed wound ointments for 2 hours. Discs were then sonicated and cultured to quantitate any remaining viable biofilm. To assess cytotoxic effects of wound ointments, L-929 fibroblasts were exposed to 2% extracts of each ointment. The trypan exclusion test was used to access cell viability and Alamar blue was used to assess metabolic function. Ointments tested include, PG+CAP formulated in an inert ointment base, benzalkonium chloride quaternary ammonia antiseptic ointment (BZK), polyhexamethylene biguanide (PHMB) antiseptic ointment, and 2-hydroxyethylcellulose + glycerol inert ointment base. Untreated fibroblast cells were used as controls. Results Within 2 hours of exposure, PG+CAP ointment able to completely eradicate C. albicans (CA), MDR Pseudomonas aeruginosa (PS), and MRSA. Additionally, PG+CAP was significantly more efficacious than BZK for MRSA (P = 0.002) and PS (P = 0.015) and PHMB for MRSA (P = 0.02). In the trypan blue exclusion test PG+CAP yielded 96.29% viable cells compared with 77.83% and 83.25%, for the QUAT and PHMB ointments, respectively. Fibroblasts treated with 2% PG+CAP, retained 86.6% of metabolic activity compared with untreated cells while the QUAT and PHMB ointments retained 37.5% and 44.5% metabolic activity, respectively. Conclusion PG+CAP has enhanced effects on eradication of biofilm in vitro as well as less toxicity in vitro relative to the antiseptic wound ointments. Further in vivo studies are warranted. Disclosures All authors: No reported disclosures.