Search

A key role of bacterial biofilm in the pathogenesis of chronic rhinosinusitis (CRS) with (CRSwNP) and without nasal polyps (CRSsNP) is commonly accepted. However, the impact of some bacterial species isolated from inflamed sinus mucosa on biofilm formation is unclear. In particular, the role of Staphylococcus epidermidis as aetiological agents of CRS is controversial. Moreover, the effect of biofilm formation on neutrophil infiltration and activity in CRSwNP calls for explanation. In this study, biofilms were found in three of 10 patients (mean age = 46 ± 14) with CRS undergoing endoscopic sinus surgery by means of scanning electron microscopy. Unexpectedly, S. epidermidis was the primary isolated bacteria and was also found to be present in all biofilm-positive mucosa specimens, indicating its pivotal role in the pathogenesis of severe chronic infections associated with biofilm formation. We have also measured the activity of myeloperoxidase (MPO), the most abundant neutrophil enzyme, to demonstrate the presence of neutrophils in the samples tested. Our present results show that the level of MPO in CRS associated with biofilm is lower than that without biofilm. It may suggest either a low number of neutrophils or the presence of a type of neutrophils with compromised antimicrobial activity, described as biofilm-associated neutrophils (BAN). Finally, we conclude that further studies with a large number of CRS cases should be performed to establish the association between S. epidermidis and other frequently isolated bacterial species from paranasal sinuses, with the severity of CRS, biofilm formation and the infiltration of BAN., (© 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.)

The aim of this study was to assess the influence of bacterial biofilms in chronic rhinosinusitis (CRS) patients on the clinical outcomes following endoscopic sinus surgery (ESS). This was a prospective, double-blind study. Patients undergoing ESS, because of CRS, were recruited. Overall 80 patients were qualified. For each of these demographic, clinical and radiologic characteristics were recorded. During surgery each patient had at least 7 mucosal specimens taken to assess, using scanning electron microscopy, the possible presence of bacterial biofilms. Prior to mucosa specimen excision, swabs for bacteriological and fungal analyses were taken. Each patient underwent perioperative and follow-up assessment at 3 and 6 months post-ESS. Biofilms were found in 33 (41.3%) patients (study group). From among the 47 patients without the presence of biofilms, 33 (control group) were taken to match the study group in age, gender and clinical characteristics. The intensity of subjective and objective CRS symptoms, as well as patient quality-of-life, did not correlate with the Lund and Mackay score (p > 0.05). Analysis of variance showed that, in the control group or the group as a whole, the intensity of subjective and objective symptoms decreased (p < 0.05), and the quality-of-life increased with time (p < 0.05). In conclusion, biofilm-positive patients tend to have a greater severity of disease preoperatively and continue to have persistent and more severe symptoms post-ESS. This study supports the role of biofilms in maintaining the chronic and recalcitrant nature of CRS. The lack of planktonic bacteria in post-operative sinus swabs does not rule out the presence of bacterial biofilms.