The effect of endoscopic sinus surgery on bacterial biofilms in chronic rhinosinusitis

Matrix-Mediated Delivery of Silver Nanoparticles for Prevention of Staphylococcus aureus and Pseudomonas aeruginosa Biofilm Formation in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a chronic health condition affecting the sinonasal cavity. CRS-associated mucosal inflammation leads to sinonasal epithelial cell death and epithelial cell barrier disruption, which may result in recurrent bacterial infections and biofilm formation. For patients who fail medical management and elect endoscopic sinus surgery for disease control, bacterial biofilm formation is particularly detrimental, as it reduces the efficacy of surgical intervention. Effective treatments that prevent biofilm formation in post-operative patients in CRS are currently limited. To address this unmet need, we report the controlled release of silver nanoparticles (AgNps) with silk-elastinlike protein-based polymers (SELPs) to prevent bacterial biofilm formation in CRS. This polymeric network is liquid at room temperature and forms a hydrogel at body temperature, and is hence, capable of conforming to the sinonasal cavity upon administration. SELP hydrogels demonstrated sustained AgNp and silver ion release for the studied period of three days, potent in vitro antibacterial activity against Pseudomonas aeruginosa (**** p < 0.0001) and Staphylococcus aureus (**** p < 0.0001), two of the most commonly virulent bacterial strains observed in patients with post-operative CRS, and high cytocompatibility with human nasal epithelial cells. Antibacterial controlled release platform shows promise for treating patients suffering from prolonged sinonasal cavity infections due to biofilms.

The Microbiology of Acute Exacerbations in Chronic Rhinosinusitis - A Systematic Review

Background

Acute exacerbations (AE) in chronic rhinosinusitis (CRS) are a common and important clinical issue. However, relatively little is known regarding the underlying microbiology that drives exacerbations or how it relates to the microbiome of CRS. The purpose of this study is to examine the literature to characterize the microbiome associated with acute exacerbations in a chronic rhinosinusitis setting. Understanding this disease process may facilitate targeted antibiotic therapy, reduced antibiotic resistance, and offer more effective disease control and treatment efficacy.

Objective

To characterize the microbiome associated with acute exacerbations of chronic rhinosinusitis (AECRS).

Methods

We conducted a systematic review of the literature on Medline, Embase, and Web of Science databases from January 1990-June 2021 to identify studies related to AE in CRS. Exclusion criteria include non-English, non-human studies, and case reports. Studies without culture or PCR data were also excluded.

Results

Fourteen studies were identified which provided detailed data regarding sinus microbiome in AECRS patients. In these patients, a total of 1252 individual isolates were identified. While common acute pathogens were identified in high frequencies in the sinonasal cultures (Staphylococcus pneumonia, Haemophilus influenza), the predominant bacteria were Staphylococcus aureus (including methicillin-sensitive Staphylococcus aureus) and Pseudomonas aeruginosa. Patient characteristics that may represent higher risk phenotypes were not consistently collected in the studies. Discussion of antimicrobial sensitivities and/or resistance were included in 7/14 studies.

Conclusions

This systematic review identifies the predominant microbiology species that may contribute to AECRS. Further studies are needed to understand the pathogenic role of bacteria and viruses in AECRS and to identify associated comorbidities and patient phenotypes that may predispose to AE. The optimal treatment regimen for AECRS remains unclear.

Comparative analysis of the outcome of external and endoscopic frontal sinus surgery in children

Background: Both open and functional endoscopic sinus surgery (FESS) are performed in the case of pediatric frontal rhinosinusitis. However, data from comparative analysis of these surgery types are insufficient.Objective: Prospective randomized trial for comparison of open and endoscopic surgery outcome in pediatric chronic rhinosinusitis.Material and methods: The cohort included 30 pediatric patients (7-17 years) with open frontal sinus surgery and 34 patients who underwent FESS using DrafIIa. Lund-Kennedy and Lund-Mackay scores, as well as Sino-Nasal Outcome Test-20 (SNOT-20)questionnaire was used for pre- and postoperative assessment.Results: Open surgery and FESS resulted in a significant improvement in total Lund-Kennedy, Lund-Mackay, and SNOT-20 scores, being more profound in FESS group. Using FESS significantly reduced surgery duration by 15% as compared to open surgery. In addition, open surgery was associated with a higher rate of scar formation, reduced local sensitivity, as well as local soreness, lacrimation, and psychological discomfort. In regression models FESS was negatively associated with postoperative total Lund-Kennedy, Lund-Mackay, and SNOT-20 scores.Conclusion and significance: Generally, FESS resulted in better surgery outcome as compared to open surgery, although both approaches resulted in a significant improvement in chronic rhinosinusitis.

In Vivo Biofilm Formation, Gram-Negative Infections and TAS2R38 Polymorphisms in CRSw NP Patients

OBJECTIVES

Among the predisposing factors implicated in the immune response to airway bacterial infections, genetic variations of the bitter taste receptor TAS2R38, which is expressed in the cilia of the human sinonasal epithelial cells, seem to be associated with susceptibility to chronic rhinosinusitis (CRS) and in vitro biofilm formation. Polymorphisms in TAS2R38 generate two common haplotypes: the nonfunctional AVI (Alanine, Valine, Isoleucine) and the functional PAV (Proline, Alanine, Valine) alleles, with the latter protecting against gram-negative sinonasal infections. The aim of this study is to investigate for the first time the relevance of TAS2R38 genetic variants in the susceptibility to bacterial infections associated with in vivo biofilm formation in chronic rhinosinusitis with nasal polyps (CRSwNP) patients.

STUDY DESIGN

A prospective study on 100 adult patients undergoing functional endoscopic sinus surgery (FESS) for CRSwNP.

METHODS

Propylthiouracile (PROP) testing and TAS2R38 genotyping were applied to characterize patients for receptor functionality. Sinonasal mucosa samples were processed for microbiological examination and biofilm detection.

RESULTS

The nonfunctional genotype is more frequent among CRS patients than in the general population (25% vs. 18.4%, P = 0.034). Airway gram-negative infections are primarily associated with the AVI haplotype (88.9% vs. 11.1% PAV/PAV-functional genotype, P = 0.023). Biofilm formation is prevalent in CRS patients with the AVI nontaster phenotype (62.5% vs. 33.3% PAV taster or supertaster phenotype, P = 0.05).

CONCLUSION

Our findings confirm an inverse correlation between TAS2R38 functionality and gram-negative infections in Italian patients with CRSwNP. In addition, for the first time we demonstrated a relationship between in vivo microbial biofilm and TAS2R38 receptor variants.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:E339-E345, 2018.

Biofilm and Osteitis in Refractory Chronic Rhinosinusitis

Our understanding of chronic rhinosinusitis (CRS) show biofilm and osteitis play a role in the disease's pathogenesis and refractory. Studies point to its role in pathogenesis and poor prognosis. Outside the research laboratory, biofilm detection remains difficult and specific treatment remains elusive. It is believed that osteitis is a nidus of inflammation and occurs more commonly in patients with refractory CRS. However, osteitis may be exacerbated by surgery and a marker of refractory disease, not a causative agent. Surgery remains the mainstay treatment for biofilm and osteitis with mechanical disruption and removal of disease load providing the most effective treatment.

Biofilms in chronic rhinosinusitis: Pathophysiology and therapeutic strategies

BACKGROUND

There is increasing evidence that biofilms are critical to the pathophysiology of chronic infections including chronic rhinosinusitis (CRS). Until relatively recently, our understanding of biofilms was limited. Recent advances in methods for biofilm identification and molecular biology have offered new insights into the role of biofilms in CRS. With these insights, investigators have begun to investigate novel therapeutic strategies that may disrupt or eradicate biofilms in CRS.

OBJECTIVE

This review seeks to explore the evidence implicating biofilms in CRS, discuss potential anti-biofilm therapeutic strategies, and suggest future directions for research.

RESULTS

The existing evidence strongly supports the role of biofilms in the pathogenesis of CRS. Several anti-biofilm therapies have been investigated for use in CRS and these are at variable stages of development. Generally, these strategies: 1) neutralize biofilm microbes; 2) disperse existing biofilms; or 3) disrupt quorum sensing. Several of the most promising anti-biofilm therapeutic strategies are reviewed.

CONCLUSIONS

A better understanding of biofilm function and their contribution to the CRS disease process will be pivotal to the development of novel treatments that may augment and, potentially, redefine the CRS treatment paradigm. There is tremendous potential for future research.

Understanding Biofilms in Chronic Sinusitis

Chronic sinusitis is a burdensome disease that has substantial individual and societal impact. Although great advances in medical and surgical therapies have been made, some patients continue to have recalcitrant infections. Microbial biofilms have been implicated as a cause of recalcitrant chronic sinusitis, and recent studies have tried to better understand the pathogenesis of chronic sinusitis as it relates to microbial biofilms. Here, we provide an overview of biofilms in chronic sinusitis with emphasis on pathogenesis, treatment, and future directions. In addition, recent evidence is presented, elucidating the role of bitter taste receptors as a possible key factor leading to biofilm formation.

Biofilm-forming bacteria and quality of life improvement after sinus surgery

BACKGROUND

It remains unclear how much chronic rhinosinusitis (CRS) patients with bacterial biofilms can benefit from functional endoscopic sinus surgery (FESS). We aimed to evaluate whether biofilm-forming bacteria was associated with quality of life (QOL) improvement after FESS.

METHODS

This retrospective cohort study included adult CRS patients who underwent FESS from 2008 to 2011. Sinus samples were taken to evaluate for biofilm-formation in vitro using a modified Calgary Biofilm Detection Assay. QOL was measured before FESS, and 1-month, 3-month, and 6-month after FESS using 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Patients' characteristics and medications were collected. Clinical significant QOL change was defined as a difference of at least 0.5 standard deviation (SD) of baseline SNOT-22 score in the reference group.

RESULTS

A total of 156 patients had complete data, and 15% had biofilm-forming bacteria (n = 24). Patients with biofilm-forming bacteria had significantly worse preoperative SNOT-22 scores compared to patients without biofilm-forming bacteria (48 ± 20 vs 38 ± 23, p = 0.048). Both groups had clinically significant QOL improvement after FESS, and the differences in their 1-month (23 ± 19 vs 17 ± 20) and 3-month (27 ± 18 vs 18 ± 19) post-FESS SNOT-22 scores were not significant. However, patients with biofilm-forming bacteria demonstrated significantly less QOL improvement than patients without biofilm-forming bacteria from pre-FESS to 6-month post-FESS visits after adjusting for clinical factors (35 ± 25 vs 14 ± 15; β-coefficient = 0.71; 95% confidence interval [CI], 0.13 to 1.28; p = 0.016).

CONCLUSION

CRS patients with biofilm-forming bacteria demonstrated clinically significant QOL improvement following FESS, but the degree of improvement was decreased overtime and became significantly worse than patients without biofilm-forming bacteria by 6-month follow-up. This QOL worsening was independent of other risk factors for CRS.

Clinical characteristics of biofilms in patients with chronic rhinosinusitis: a prospective case-control study

Recent studies have indicated that biofilms are involved in the pathogenesis of recurrent and recalcitrant chronic rhinosinusitis (CRS). The present study was performed to evaluate the presence of biofilms and to evaluate the relationships between the presence of biofilms and clinical features of CRS. A total of 33 patients were included in this study. Maxillary sinus mucosa from 26 CRS patients and the ethmoid mucosa from 7 patients undergoing septoplasty were collected. Biofilms were evaluated by scanning electron microscopy. Preoperative symptom scores, preoperative and intraoperative nasoendoscopic findings, and postoperative healing period were compared between the groups. Biofilms were detected in 14 (42.4 %) of the 33 patients. Biofilms were present in 13 (50 %) of the 26 patients in the CRS group, but in only one (14.3 %) of the seven patients in the control group. There were no significant differences in preoperative symptom scores or preoperative nasal Lund-Kennedy endoscopic scores between the groups. However, the average Lund-Mackay and intraoperative sinus Lund-Kennedy endoscopic scores were significantly higher in biofilm-positive than biofilm-negative patients (P < 0.05). In the follow-up period, the healing time was significantly longer in biofilm-positive than biofilm-negative patients (P < 0.05). This study suggested that the presence of bacterial biofilms may contribute to the pathogenesis of CRS and the clinical characteristics of CRS patients after endoscopic sinus surgery.

Satisfaction with maxillary sinus surgery might be influenced by risk factors

Chronic rhinosinusitis (CRS) is an inflammation of the nose and paranasal sinuses lasting for ≥12 weeks. Endoscopic sinus surgery (ESS) is considered during difficult to treat CRS. The minimally invasive technique focuses on the transition areas rather than on the ostia. The aim of this study was to evaluate symptoms, the number of acute sinusitis episodes, and satisfaction after ESS with either preservation or enlargement of the maxillary sinus ostium. Thirty patients with moderate nonpolypous CRS were enrolled. Uncinectomy only and additional middle meatal antrostomy were randomized for each side of each patient and performed single blindly. The symptoms questionnaires were filled at four time intervals. Significant symptom reduction was achieved independently of operation technique. The number of acute sinusitis episodes indicating the exacerbation rate decreased significantly at 9 and, on average, 68 months postoperatively. However, the exacerbation rate began to increase after 9 months postoperatively. Three revisions were performed on the side with uncinectomy only and one on the side with additional antrostomy. Most patients reported good satisfaction with both procedures. There was a trend for patients with asthma and/or job exposure to report insignificantly more frequently no satisfaction with surgery, especially with the uncinectomy-only procedure. Both procedures seem to be efficient in providing symptom relief and satisfaction. More studies are needed to evaluate if patients with risk factors benefit more from an ostium-enlarging procedure.

Quality of life in patients with chronic rhinosinusitis

Health-related quality of life (HRQoL) is a domain of quality-of-life assessment that is influenced by the individual's perception of his or her health status. Measurement of HRQoL can enable physicians to understand how an illness interferes with a patient's day-to-day life, improve patient-physician communication, and optimize clinical outcomes. Chronic rhinosinusitis (CRS) is one of the most common chronic diseases, affecting 14-16% of the adult US population. In addition to significant health care costs, CRS has been shown to substantially reduce HRQoL. In this review article, we discuss the definition and interpretation of HRQoL data and describe several validated rhinosinusitis HRQoL instruments. Additionally, we review how CRS functions to lower HRQoL and the effect of medical and surgical intervention on improving HRQoL status. By understanding the relationship between CRS and associated chronic conditions, clinicians can target their evaluation to problems that will maximize clinical success.

Relationship between bacterial biofilm and clinical features of patients with chronic rhinosinusitis

The purpose of this study was to investigate the incidence of bacterial biofilm (BBF) in patients with chronic rhinosinusitis (CRS) using confocal scanning laser microscopy (CSLM), and to assess the relationship between BBF and clinical features of CRS. This was a prospective observational study of the sinus mucosa of 27 CRS patients and 10 controls undergoing endoscopic sinus surgery (ESS). Clinical information was recorded preoperatively and sinus mucosal specimens were collected intraoperatively. We determined the existence of BBF with BacLight/CSLM detection, and proposed a BBF scoring system based on its morphologic features. Clinical parameters, including symptom score, endoscopy score, CT score and symptom duration, were compared between CRS patients with and without BBF, and among CRS patients with different BBF score. BBF was found in 16/27 (59.26%) CRS patients and none in 10 controls. SNOT-20 symptom score and individual symptoms including need to blow nose, cough and postnasal discharge were significantly more severe in CRS patients with BBF than those without. BBF score was better correlated than BBF existence with SNOT-20 score (r = 0.811, P < 0.001 vs. r = 0.604, P = 0.001), and correlated with both endoscopy score (r = 0.490, P = 0.009) and symptom duration (r = 0.487, P = 0.010), neither was correlated with BBF (P = 0.824; P = 0.263). BBF score is likely to guide anti-BBF therapy in CRS patients.

Do biofilms contribute to the initiation and recalcitrance of chronic rhinosinusitis?

Chronic rhinosinusitis is a common disease whose underlying aetiopathogenesis has not been completely understood. Amongst a range of other potential environmental triggers in this disease, a role has recently been proposed for bacterial biofilms. Adopting the biofilm paradigm to explain the initiation and maintenance of this disease may help to clarify previous inconsistencies in this disease that have resulted in the role of bacteria being questioned. Of particular interest is the association of bacterial biofilms with recalcitrant disease states. Over the last five years, research has progressed rapidly since biofilms were first identified on the surface of diseased sinonasal mucosa. Their presence there has now been associated with more severe disease that is often recalcitrant to current management paradigms. Technological advances are allowing accurate characterization of the bacterial and fungal species within these biofilms, which would appear to be an important step in improving our understanding of how these bacterial communities might interact with the host to cause disease. This is an unanswered, yet highly important, question in this field of research that will undoubtedly be an area of investigation in the near future. As the body of evidence suggesting biofilms may be involved in this disease grows, research interest has switched to the development of antibiofilm therapies. Given the unique properties of bacteria existing in this form, biofilm eradication strategies will need to incorporate novel medical therapies into established surgical practices as we attempt to improve the outcomes of our most difficult patients.

What is the origin of Staphylococcus aureus in the early postoperative sinonasal cavity?

BACKGROUND

Despite increasing evidence of a role for Staphylococcus aureus (S. aureus) biofilms in chronic rhinosinusitis (CRS), the origin of this organism in the postsurgical sinonasal cavity had been unclear. Recently, we suggested that the increased culture rate of S. aureus following endoscopic sinus surgery (ESS) may be related to biofilm activity. This study, therefore, was designed to evaluate the origin of early postoperative sinonasal S. aureus and assess the early postoperative outcomes in patients culture-positive for this organism.

METHODS

Twenty-nine patients undergoing ESS for medically-recalcitrant CRS were prospectively enrolled. A comprehensive intraoperative S. aureus screening protocol was followed for all patients (including swabs for culture and tissue for fluorescence in situ hybridization [FISH] S. aureus biofilm analysis); early postoperative management included endoscopically-guided swabs for culture in all patients.

RESULTS

Twenty of 29 (69.0%) patients cultured S. aureus postoperatively, of which 17 of 20 (85.0%) were screen-positive at surgery. Seven of 11 (63.6%) intraoperatively biofilm-positive but culture-negative patients progressed to culture S. aureus post-ESS. S. aureus culture was associated with selected poorer early post-ESS outcomes.

CONCLUSION

S. aureus persists in the sinonasal cavity despite ESS. The postoperative culture of sinonasal S. aureus in patients previously biofilm-positive but culture-negative may reflect the dynamic ability of S. aureus to adapt to the surgically-altered microenvironment with subsequent biofilm dispersal and release of planktonic clones.

Clinical Factors Associated with Bacterial Biofilm Formation in Chronic Rhinosinusitis

Objectives. Bacterial biofilms appear to contribute to chronic rhinosinusitis. However, the mechanism behind biofilm formation in chronic rhinosinusitis remains poorly defined. The aim of this study is to evaluate clinical factors that may be associated with bacterial biofilm formation in chronic rhinosinusitis.

Study Design. Cross-sectional study.

Setting. Department of Otorhinolaryngology–Head and Neck Surgery at the Hospital of the University of Pennsylvania.

Subjects and Methods. Five hundred eighteen patients with chronic rhinosinusitis were enrolled from 2007 to 2010. Samples were taken to evaluate for biofilm formation in vitro using a modified Calgary Biofilm Detection Assay. Clinical data were collected from chart review. Pearson’s χ2 and logistic regression were used for the analyses.

Results. Of the patients, 108 (20.9%) showed biofilm formation in vitro. Bacterial biofilm formation in vitro was not significantly associated with polyps, allergy, Samter’s triad, sleep apnea, smoking status, age, or gender. However, it was significantly associated with positive culture results (odds ratio [OR] = 3.13; 95% confidence interval [CI], 1.85-5.29; P < .001), prior sinus surgeries (1.93; 1.01-3.69; P = .046), and nasal steroid use in the month prior to sample collection (2.09; 1.07-4.08; P = .030). Polymicrobial cultures, Pseudomonas aeruginosa, and Staphylococcus aureus comprised most of the samples.

Conclusion. The results of this study suggest that the probability of bacterial biofilm formation is independent of many clinical factors considered to be risk factors for chronic rhinosinusitis. Further studies are needed to clarify the nature of the associations between prior sinus surgeries, nasal steroid use, and biofilm formation.