[Detection of bacterial biofilm in human refractory chronic rhinosinusitis with Scanning Electron Microscopy [SEM]]

ABSTRACT

Bacterial biofilm is a complex organization of bacteria anchored to a mucosal surface. A recent but fascinating notion in the pathphysiology of chronic rhinosinusitis is the role of bacterial biofilms. Biofilms explain why in individuals with normal immunity, antibiotics are unable to resolve bacteria that are sensitive to antibiotics on in vitro testing. This is the first study in Iran, in which we demonstrate the biofilms in ethmoid sinus mucosa of patients with refractory chronic rhinosinusitis after one successful surgery. 10 patients included, all of them had at least one previously technically successful FESS for a diagnosis of chronic rhinosinusitis [CRS] and/or nasal polyposis that were refractory to maximal medical therapy over months previously. Patients were not immune compromised and not taken antibiotics or systemic corticosteroids within a 1 month period previously, but taking nasal irrigation or topical intranasal corticosteroids. During postoperative endoscopy, four punch biopsies were obtained from ethmoid sinus. The specimens were examined by SEM. Photomicrographs were then evaluated for evidence of biofilms. Biofilm in SEM was defined as the presence of microcolonies embedded in a microfilament extrapolysaccharide matrix. The biofilms were not identified within the mucosa, but were identified on the mucosal surface. Biofilms were detected in 6 of 10 patients. Biofilms may play role in refractory chronic rhinosinusitis. Biofilms are refractory to antibiotics and often only cured by mechanical debridement