Alkis J. Psaltis

Confocal Scanning Laser Microscopy Evidence of Biofilms in Patients With Chronic Rhinosinusitis

Objectives: The recent detection of bacterial biofilms on the sinus mucosa of patients with chronic rhinosinusitis (CRS) has implicated biofilms in the pathogenesis of this condition. Electron microscopy has been the main modality used to document the presence of biofilms on sinus tissue, however, it has inherent problems associated with tissue preparation and sampling. Recently, Confocal Scanning Laser Micrsocopy (CSLM) has emerged as a noninvasive, nondestructive technique for the analysis of biofilms. This study used CSLM as the means of investigating biofilm presence in CRS patients.

The effect of bacterial biofilms on post-sinus surgical outcomes

Background Although the existence of biofilms on the sinus mucosa of patients with chronic rhinosinusitis (CRS) is now well established, the role that these structures play remains unclear. It is thought that biofilms may contribute to the recalcitrant and persistent nature that characterizes CRS, but little research exists documenting the effect that they have on postoperative mucosal outcomes. This article presents a retrospective analysis of sinus surgical patients and correlates the presence of biofilms with mucosal outcomes. This study was performed to evaluate the role that bacterial biofilms have on post-sinus surgical outcomes. Methods A retrospective analysis of prospectively collected data was performed on 40 patients undergoing endoscopic sinus surgery (ESS) for CRS. Preoperative demographic, clinical, and radiologic data were recorded from each patient and, intraoperatively, sinus culture specimens and mucosal samples were obtained for microbiological and microscopic examination. Biofilm determination was performed using confocal scanning laser microscopy. Postoperatively, patients were followed up for a minimum of 8 months with endoscopic evaluation of their sinonasal mucosa. The presence of ongoing symptoms was recorded also. Results Bacterial biofilms were found in 20 (50%) of the 40 CRS patients. Patients with biofilms had significantly worse preoperative radiological scores and, postoperatively, had statistically worse postoperative symptoms and mucosal outcomes. The only other factor that was statistically related to an unfavorable outcome was the presence of fungus at the time of surgery. In this study the presence of polyps, eosinophilic mucin, or pus was not related to poor outcomes. Conclusion This retrospective study showed that bacterial biofilms and fungus were correlated with the persistence of postoperative symptoms and mucosal inflammation after sinus surgery for CRS. This provides evidence that biofilms indeed may play an active role in perpetuating inflammation in CRS patients and may explain the recurrent and resistant nature of this disease. Therapies targeted at removing biofilms may be important in the management of recalcitrant CRS.

Characterization of bacterial and fungal biofilms in chronic rhinosinusitis.

Background Conclusive evidence exists that biofilms are present on the mucosa of chronic rhinosinusitis (CRS) patients. Less is known about the species constituting these biofilms. This study developed a fluorescence in situ hybridization (FISH) protocol for characterization of bacterial and fungal biofilms in CRS. Methods Fifty CRS patients and 10 controls were recruited. Bacteria FISH probes for Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa and a universal probe for fungi were applied to sinus mucosal specimens and then analyzed using confocal scanning laser microscopy. Results Thirty-six of 50 CRS patients had biofilms present in contrast to 0/10 controls, suggesting a role for biofilms in the pathogenesis of this disease. S. aureus was the most common biofilm-forming organism. Eleven of 50 CRS patients had characteristic fungal biofilms present. Conclusion This is the largest study of biofilms in CRS. It has validated mucosal tissue cryopreservation for delayed biofilm analysis. Fungal biofilms have been identified and the importance of S. aureus biofilms in the polymicrobial etiology of CRS is highlighted.

Adaptive immune responses in Staphylococcus aureus biofilm–associated chronic rhinosinusitis

To cite this article: Foreman A., Holtappels G., Psaltis A.J., Jervis‐Bardy J., Field J., Wormald P.‐J., Bachert C. Adaptive immune responses in Staphylococcus aureus biofilm–associated chronic rhinosinusitis. Allergy 2011; 66: 1449–1456.

The Impact of Biofilms on Outcomes after Endoscopic Sinus Surgery

Background Although biofilms have been implicated in the pathogenesis of chronic rhinosinusitis (CRS), there is little evidence that their presence or absence has any effect on the outcomes of endoscopic sinus surgery (ESS). The aim of this study was to investigate the effect of biofilms on postsurgical outcomes after ESS. Methods A prospective, blinded study of 51 consecutive patients undergoing ESS for CRS was conducted. Preoperatively, patients assessed their symptoms using internationally accepted standardized symptom scoring systems and quality-of-life (QOL) measures, i.e., the 10-point Visual Analog Scale (VAS), Sino-Nasal-Outcome-Test 20, and global severity of CRS. Their sinonasal mucosa was graded using the Lund-Kennedy scale and the extent of radiological disease on computed tomography scans was scored using the Lund-McKay scale. Random sinonasal tissue samples were assessed for biofilm presence using confocal laser microscopy. At each postoperative visit, patients reassessed their sinus symptoms and completed QOL measures. Postsurgical state of their sinonasal mucosa was graded endoscopically. Results Bacterial biofilms were found in 36 of 51 (71%) CRS patients. Patients with biofilms presented with significantly worse preoperative radiology and nasendoscopy scores (p = 0.003 and 0.01, respectively). After a median follow-up period of 16 months postsurgery, biofilm-positive patients had statistically worse sinus symptoms (VAS, p = 0.002) and worse nasendoscopy scores (p = 0.026). They also required extra postoperative visits and multiple antibiotic treatments deviating from the standard postoperative care required by biofilm-negative patients. Conclusion This study has shown that patients with biofilms have more severe disease preoperatively and persistence of postoperative symptoms, ongoing mucosal inflammation, and infections. This study strengthens the evidence for the role that biofilms may play in recalcitrant CRS.

Nasal Lavage With Mupirocin for the Treatment of Surgically Recalcitrant Chronic Rhinosinusitis

Objectives/Hypothesis: To examine the efficacy and tolerability of topical mupirocin for the management of surgically recalcitrant chronic rhinosinusitis (CRS) associated with Staphylococcus aureus infection.

In Vitro Activity of Mupirocin on Clinical Isolates of Staphylococcus aureus and its Potential Implications in Chronic Rhinosinusitis

Background: It has been postulated that bacterial biofilms are involved in the pathogenesis of chronic rhinosinusitis (CRS). Biofilms present on sinus mucosa are difficult to eradicate with conventional antibiotic therapy and are thought to provide a nidus for recurrent infection. Topical delivery of antibiotics via nasal irrigation may present a way of delivering high concentrations of antibiofilm agents with potentially low systemic absorption and side effects. This study investigates the effectiveness of mupirocin and two other antibiotics, ciprofloxacin and vancomycin, on established in vitro biofilms of Staphylococcus aureus isolated from patients with CRS.

A sheep model for the study of biofilms in rhinosinusitis.

Background Bacterial biofilms have been shown in chronic diseases such as cystic fibrosis, cholesteatoma, and otitis media with effusion. Recently, their detection on the mucosal tissue of sinusitis patients has implicated them in the pathogenesis of this condition. We present an animal model using sheep experimentally infected with Staphylococcus aureus to study the possible association between biofilm and sinusitis. Methods Twenty-four sheep underwent bilateral endoscopic sinus surgery to identify their frontal ostia. The frontal sinuses were treated in one of the following ways according to preoperative randomization: (1) ostium left patent, (2) ostium left patent and bacteria instilled, (3) ostium occluded, or (4) ostium occluded and bacteria instilled. The frontal mucosa was harvested at day 7 and examined for biofilm presence using confocal scanning laser microscopy (CSLM) as well as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results All three modalities showed different rates of biofilm detection. Three-dimensional structures that could be interpreted as biofilms were documented in 86% (n = 36) of the sinuses analyzed using SEM. These structures were seen in all four study groups. The detection rate using the other two modalities was much lower with CSLM, showing biofilms in 48% (n = 20) and TEM in only 29% (n = 12) of the sinuses analyzed. Unlike SEM, these two modalities only detected bacterial biofilms in sinuses randomized to bacterial instillation. Conclusion The demonstration of bacterial biofilms in this animal model of sinusitis further supports the hypotheses that biofilms may play a role in the pathogenesis of this condition. There is an obvious discrepancy in the sensitivity and specificity of biofilm detection using the three modalities mentioned. CSLM appears to be the most objective technique. The inherent flaws, sampling error, and subjectivity involved in SEM and TEM make these less reliable in documenting biofilm existence.

Reduced Levels of Lactoferrin in Biofilm-Associated Chronic Rhinosinusitis†

Objective/Hypothesis: The diverse antipathogenic action of lactoferrin has been well characterized. In addition, it is the human bodys only known antimicrobial peptide with antibiofilm properties. The purpose of this study was to examine the nasal mucosal expression of lactoferrin in the biofilm‐mediated disease, chronic rhinosinusitis (CRS).

A systematic review of the endoscopic repair of cerebrospinal fluid leaks.

Objectives To provide an up-to-date review of the literature on the safety and efficacy of the endoscopic technique for cerebrospinal (CSF) leak repairs. Data Sources PubMed, Medline/Old Medline, and Cochrane Central databases. Review Methods Using the above outlined data sources, studies involving the endoscopic repair of CSF leaks were reviewed independently by 2 researchers. Studies included met the following criteria: full-text article written in the English language, at least 5 human patients undergoing purely endoscopic surgical repair of a CSF leak, and documented follow-up. Data extracted included leak etiology, presentation and location, the use of imaging, intrathecal fluorescein, and adjunctive measures as well as the success rate of the repair. Results Fifty-five studies, involving 1778 fistulae repairs, were included for analysis. Spontaneous leaks were most prevalent, with the ethmoid roof and sphenoid the most common sites involved. The overall success rate of repair was high at 90% for primary and 97% for secondary repairs. A low complication rate of less than 0.03% was reported. Conclusion The endoscopic repair of CSF fistula is both safe and effective and should be considered the standard of care for most cases. Evidence supporting adjunctive measures such as lumbar drains and antibiotics remains limited despite their common use.