Bacterial biofilms in surgical specimens of patients with chronic rhinosinusitis

Biofilms are bacterial pathogens that organize in several chronic and recalcitrant infectious processes. We hypothesize that biofilms play a role in chronic rhinosinusitis (CRS). Our goal is to demonstrate biofilms in mucosal specimens of patients undergoing surgery for CRS.

A prospective study of the presence of biofilms in patients undergoing endoscopic sinus surgery for CRS compared with control patients without CRS.

There were a total of 30 subjects and 4 controls enrolled. The samples of 24 subjects and 4 controls were cultured and then prepared using standard methods for scanning electron microscopy (SEM). The remaining six subjects' samples were treated using advanced cryofixation methods as preparation to preserve structure for SEM and transmission electron microscopy (TEM).

Using strict SEM morphologic criteria, 24 (80%) of the 30 patients were found to have micrographic evidence of biofilms. All controls had healthy appearing cilia and goblet cells without biofilms. The six cryofixation samples showed biofilm structures on SEM micrographs that were correlated with bacterial structures seen at the mucosal surface on the corresponding TEM cross sections. Bacterial cultures were positive on all patients.

Biofilms were demonstrated to be present in patients undergoing surgery for CRS; none of the patients without CRS had any evidence of biofilms. Although SEM is capable of demonstrating the biofilms' three-dimensional structure, glycocalyx, and water channels, it cannot clearly demonstrate the presence of bacteria within the biofilm. We were able to demonstrate evidence of bacteria in the biofilms on the subjects tested using TEM.