Fellow in Rhinology and Skull Base Surgery Rush University
Background: Chronic rhinosinusitis(CRS) refractory to treatment is commonly associated with biofilm formation. Pseudomonas aeruginosa-derived biofilms have been associated with resistance to antimicrobial treatments and worse outcomes. The profile of biofilm exopolysaccharides produced by P. aeruginosa in sinonasal cavities of CRS patients has yet to be determined. Novel recombinant microbial glycoside hydrolases (GH), PslGh and PelAh, have shown promise in degrading P. aeruginosa biofilms in vitro and in the treatment of wound infections. However, the activity of these GH against CRS sinonasal P. aeruginosa biofilms has not been evaluated.
Objectives: To characterize CRS sinonasal P. aeruginosa biofilm formation, exopolysaccharide production and susceptibility to disruption by GH.
Methods: Sixty sinonasal P. aeruginosa samples were isolated from patients with CRS. Crystal violet staining was used to assess biofilm formation. GH (PslGh, PelAh and their combinations) were tested for their activity against these P. aeruginosa biofilms in vitro.
Results: Of the 60 clinical strains isolated from 12 unique patients, 16 formed biofilms. Six of the biofilm-forming P. aeruginosa strains were susceptible to PslGh and 3 were sensitive to PelAh. Four strains were susceptible to combination treatment but resistant to PslGh and PelAh alone. Only 3 samples, derived from one unique patient, were strong biofilm formers that were not susceptible to either or both GHs.
Conclusion:This is the first study to evaluate the effect of GH on CRS P. aeruginosa biofilms. The majority of biofilm forming strains were susceptible to one or more GH. This in vitro study suggests that GHs could be potential novel therapeutic candidates in the treatment of CRS.