Antimicrobial Activity of SinuSurf

Abstract

Objective: 1) Determine the antimicrobial potential of a novel topical sinonasal surfactant, SinuSurf. 2) Evaluate whether the addition of SinuSurf™ with mupirocin or gentamicin creates an additive/synergistic effect on recalcitrant chronic rhinosinusitis (CRS) pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aurginosa (PA).

Method: MRSA and PA01 cultures were grown in 96-well plates containing 10-fold serial dilutions of mupirocin (1x = 150ug/ml) or gentamicin(1x = 80ug/ml), diluted in normal saline with or without the addition of SinuSurf. Colony forming units (CFUs) were determined 20 hours later.

Results: In the absence of antibiotics, SinuSurf evinced a 6 log reduction in CFUs for PA and 3 log reduction for MRSA. At the clinically used concentrations of respective antibiotics (80 ug/ml gentamicin, 150 ug/ml mupiricin) no growth was evident. In combination with SinuSurf, mupirocin at 1:10 dilution demonstrates complete eradication not seen with mupiricin alone. Similarly, SinuSurf in conjunction with gentamicin at 1:100 dilution demonstrates no growth while gentamicin alone at that dilution yielded growth. Furthermore, addition of SinuSurf resulted in a 5 log reduction in CFUs at a 1:100 dilution of mupirocin and 1:1000 dilution of gentamicin.

Conclusion: Bacterial biofilms have recently been demonstrated in the sinonasal cavities of CRS patients and implicated in recalcitrant disease. Bacteria in the biofilm state require 100X to 1000X concentrations of antibiotics for effective therapy. Our data demonstrate the addition of SinuSurf increases the effective in vitro concentration of antibiotics significantly.