Bacterial biofilms in chronic rhinosinusitis; distribution and prevalence

Host-microbe interactions in chronic rhinosinusitis biofilms and models for investigation

Chronic rhinosinusitis (CRS) is a debilitating condition characterized by long-lasting inflammation of the paranasal sinuses. It affects a significant portion of the population, causing a considerable burden on individuals and healthcare systems. The pathogenesis of CRS is multifactorial, with bacterial infections playing a crucial role in CRS development and persistence. In recent years, the presence of biofilms has emerged as a key contributor to the chronicity of sinusitis, further complicating treatment and exacerbating symptoms. This review aims to explore the role of biofilms in CRS, focusing on the involvement of the bacterial species Staphylococcus aureus and Pseudomonas aeruginosa, their interactions in chronic infections, and model systems for studying biofilms in CRS. These species serve as an example of how microbial interplay can influence disease progression and exemplify the need for continued investigation and innovation in CRS research.

Respiratory Nasal Mucosa in Chronic Rhinosinusitis with Nasal Polyps versus COVID-19: Histopathology, Electron Microscopy Analysis and Assessing of Tissue Interleukin-33

(1) Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most studied rhinological disorders. Modifications of the respiratory nasal mucosa in COVID-19 patients are so far unknown. This paper presents a comparative morphological characterization of the respiratory nasal mucosa in CRSwNP versus COVID-19 and tissue interleukin (IL)-33 concentration. (2) Methods: We analyzed CRSwNP and COVID-19 samples through histopathology, scanning and transmission electron microscopy and performed proteomic determination of IL-33. (3) Results: Histopathologically, stromal edema (p < 0.0001) and basal membrane thickening (p = 0.0768) were found more frequently in CRSwNP than in COVID-19. Inflammatory infiltrate was mainly eosinophil-dominant in CRSwNP and lymphocyte-dominant in COVID-19 (p = 0.3666). A viral cytopathic effect was identified in COVID-19. Scanning electron microscopy detected biofilms only in CRSwNP, while most COVID-19 samples showed microbial aggregates (p = 0.0148) and immune cells (p = 0.1452). Transmission electron microscopy of CRSwNP samples identified biofilms, mucous cell hyperplasia (p = 0.0011), eosinophils, fibrocytes, mastocytes, and collagen fibers. Extracellular suggestive structures for SARS-CoV-2 and multiple Golgi apparatus in epithelial cells were detected in COVID-19 samples. The tissue IL-33 concentration in CRSwNP (210.0 pg/7 μg total protein) was higher than in COVID-19 (52.77 pg/7 μg total protein) (p < 0.0001), also suggesting a different inflammatory pattern. (4) Conclusions: The inflammatory pattern is different in each of these disorders. Results suggested the presence of nasal dysbiosis in both conditions, which could be a determining factor in CRSwNP and a secondary factor in COVID-19.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Probiotics Streptococcus salivarius 24SMB and Streptococcus oralis 89a interfere with biofilm formation of pathogens of the upper respiratory tract

Background

Infections of the ears, paranasal sinuses, nose and throat are very common and represent a serious issue for the healthcare system. Bacterial biofilms have been linked to upper respiratory tract infections and antibiotic resistance, raising serious concerns regarding the therapeutic management of such infections. In this context, novel strategies able to fight biofilms may be therapeutically beneficial and offer a valid alternative to conventional antimicrobials. Biofilms consist of mixed microbial communities, which interact with other species in the surroundings and communicate through signaling molecules. These interactions may result in antagonistic effects, which can be exploited in the fight against infections in a sort of “bacteria therapy”. Streptococcus salivarius and Streptococcus oralis are α-hemolytic streptococci isolated from the human pharynx of healthy individuals. Several studies on otitis-prone children demonstrated that their intranasal administration is safe and well tolerated and is able to reduce the risk of acute otitis media. The aim of this research is to assess S. salivarius 24SMB and S. oralis 89a for the ability to interfere with biofilm of typical upper respiratory tract pathogens.

Methods

To investigate if soluble substances secreted by the two streptococci could inhibit biofilm development of the selected pathogenic strains, co-cultures were performed with the use of transwell inserts. Mixed-species biofilms were also produced, in order to evaluate if the inhibition of biofilm formation might require direct contact. Biofilm production was investigated by means of a spectrophotometric assay and by confocal laser scanning microscopy.

Results

We observed that S. salivarius 24SMB and S. oralis 89a are able to inhibit the biofilm formation capacity of selected pathogens and even to disperse their pre-formed biofilms. Diffusible molecules secreted by the two streptococci and lowered pH of the medium revealed to be implied in the mechanisms of anti-biofilm activity.

Conclusions

S. salivarius 24SMB and S. oralis 89a possess desirable characteristics as probiotic for the treatment and prevention of infections of the upper airways. However, the nature of the inhibition appear to be multifactorial and additional studies are required to get further insights.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3576-9) contains supplementary material, which is available to authorized users.

The Effect of Spray Cryotherapy on Microbial Biofilms in Chronic Rhinosinusitis

PURPOSE OF REVIEW

Microbial biofilms seem to play an active role in the pathogenesis of chronic rhinosinusitis (CRS). They represent an adaptive defense resource enabling resistance to antibiotics and host defense mechanisms. Biofilms are thought to be accountable for refractory cases of sinusitis by perpetuating local inflammation. The objective of this study was to assess the effectiveness of spray cryotherapy as a biofilm disruption agent in CRS in an in vitro model.

RECENT FINDINGS

A total of 23 patients with CRS undergoing endoscopic sinus surgery (ESS) were included. Rhinosinusal mucosa samples were harvested. Half of sample was left intact while the other half was treated with spray cryotherapy, so patients served as their own witnesses. Subsequently, they were processed to hematoxylin-eosin (HE) and toluidine blue (TB) staining and analyzed by light microscopy. Biofilms were detected in 17 of 23 patients with CRS. Staining by HE showed strong correlation with the results of TB staining protocol. The in vitro CRS study demonstrated that spray cryotherapy removed polymicrobial biofilms from the mucosa surface in 70.6% of cases and induced important structural changes in the remaining samples. Thus far, cryotherapy has proven to be a reliable method for the disruption of microbial biofilms in CRS with nasal polyps, in vitro conditions. Spray cryotherapy could be a considerable benefit in the management of recalcitrant CRS.

Non-surgical management of chronic rhinosinusitis with nasal polyps based on clinical-cytological grading: a precision medicine-based approach

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder that strongly impacts patients' quality of life. CRSwNP is still a challenge for ENT specialists due to its unknown pathogenesis, difficult control and frequent relapse. We tested the hypothesis that a new standardised therapeutic approach based on individual clinical-cytological grading (CCG), may improve control of the disease and prevent the needing for surgery. We analysed 204 patients suffering from bilateral CRSwNP, 145 patients of whom regularly assumed therapy, respecting the planned check-up, and were considered cases; 59 patients were not assuming therapy as indicated and were considered as controls. After five years of standardised treatment, 15 of 145 (10.5%) improved endoscopic staging, 61 of 145 (42%) did not change their endoscopic staging, and 69 of 145 (47.5%) were worse. In the control group, 49 of 59 (83%) were worse by at least two stages (p < 0.05). Patients and controls were stratified basing on clinical and cytological grading as mild, moderate and severe. After patient stratification, in the mild group (n = 27) 92% patients had a constant trend, with no worsening and no need for surgery over a 5-year period, whereas in the mild CCG control group 1 of 59 (1.6%) required surgery (p < 0.05). In moderate GCC (n = 83), 44% of patients did not modify or improve endoscopic staging and 3.6% needed surgery, compared to 13.6% of controls with moderate GCC (p < 0.05). In severe CCG (n = 35), even though no patients achieved significant amelioration of endoscopic grading, 40% of patients were considered as "clinically controlled" and 5.7% of patients underwent surgery, but the percentage was significantly higher (49%) in the control group significant (p = 0.0000). Finally, statistical analyses revealed a clear trend that polyp size increased at a faster rate in the control group than in the treatment group and for each subgroup (low, moderate and severe). The present study suggests a new approach in the management of CRS according to clinical cytological grading that allows defining the grade of CRSwNP severity and to adapt the intensity of treatment. This approach limited the use of systemic corticosteroids to only moderate-severe CRSwNP with a low corticosteroid dosage in comparison with those previously suggested. Our protocol seems to improve the adherence by patients, control of disease and the need for surgery in the long-term.

Causes of higher symptomatic airway load in patients with chronic rhinosinusitis

Background

Chronic rhinosinusitis display a variety of different phenotypes. The symptoms of disease are characterised by various signs and symptoms such as nasal congestion, nasal discharge, pressure sensation in the face and reduced or complete loss of smell.

In a patient population undergoing functional endoscopic sinonasal surgery (FESS) for chronic rhinosinusitis, we wanted to investigate the clinical features and explore if the presence of biofilm, nasal polyps or other disease characteristic could serve as predictor for the symptomatic load. A patient group undergoing septoplasty without disease of the sinuses was included as control.

Methods

The Sinonasal outcome test (SNOT-20), EPOS visual analogue scale (VAS) and the Lund-Mackey CT score (LM CT score) were used to examine 23 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), 30 patient with nasal polyps (CRSwNP) and 22 patients with septal deviation. Tissue samples were collected prospectively during surgery. The cohort has previously been examined for the presence of biofilm.

Results

Patients with CRSsNP and CRSwNP had significantly higher degree of symptoms compared to the septoplasty group (SNOT-20 scores of 39.8, 43.6 and 29.9, respectively, p = 0.034). There were no significant differences in the total SNOT-20 or VAS symptoms scores between the CRSsNP and CRSwNP subgroups. However patients with nasal polyps showed significantly higher scores of symptoms related to sinonasal discomfort such as cough, runny nose and need to blow nose (p = 0.011, p = 0.046, p = 0.001 respectively). Patients with nasal polyps showed a significantly higher LM CT score compared to patients without polyps (12.06 versus 8.00, p = 0.001). The presence of biofilm did not impact the degree of symptoms.

Conclusion

The presence of nasal polyp formations in CRS patients was associated with a higher symptomatic airway load as compared to patients without polyps. These findings suggest that nasal polyps could be an indicator of more substantial sinonasal disease. The presence of biofilm did not impact the degree of symptoms, however, as biofilm seem to be a common feature of chronic rhinosinusitis (89% in this cohort), it is more likely to be involved in the development of the CRS, rather than being a surrogate marker for increased symptomatic load.

Electronic supplementary material

The online version of this article (10.1186/s12901-017-0048-6) contains supplementary material, which is available to authorized users.

Dendritic cell subset expression in severe chronic rhinosinusitis with nasal polyps

PURPOSE OF REVIEW

Two main pillars are implicated in nasal polyposis development: a severe imbalance in immunomodulation and a mechanical dysfunction because of an abnormal remodeling process. Dendritic cells play a crucial role in the link between innate and adaptive immune response and orchestrating the T-cell response and are implicated in the severe inflammatory process found in nasal polypoid tissue. This review summarizes the existent knowledge about dendritic cells in nasal polyposis.

RECENT FINDINGS

Dendritic cells are found increased in nasal polyposis, regardless of subset. Of interest, plasmacytoid dendritic cells are decreased in patients with a more severe Th2 profile, suggesting an important role of the cytokines milieu in their functional response or that plasmacytoid dendritic cell could act mitigating the inflamed process found in polypoid tissue.

SUMMARY

Understanding the dendritic cell subset expression in different environments, as well as the effect of these subsets on T-cell differentiation will greatly improve the development of new therapies in nasal polyposis.

Low incidence of coaggregation amongst bacteria isolated from the upper respiratory tract in health and disease

The nasal cavity harbours a commensal microbiota that reportedly provides colonization resistance against respiratory pathogens. Following the onset of chronic rhinosinusitis (CRS), a change in sinus microbiota composition is frequently reported in which atypical anaerobic and/or Gram-negative bacteria predominate. We have investigated pairwise interactions between respiratory bacteria isolated from healthy adults (n=3) and individuals exhibiting CRS (n=3). Antagonism was determined using a spot plate methodology and coaggregation scores were determined using a quantitative spectrophotometric assay. Obligate anaerobes were isolated from all CRS samples and exhibited inter-host growth inhibition of commensal nasal bacteria, including Corynebacterium spp. and Staphylococcus spp. Antagonism between bacteria isolated from healthy individuals was limited to corynebacterial-mediated inhibition of the staphylococci. The frequency of coaggregation was low overall (2/153 pairwise interactions). Antagonism of the nasal microbiota by respiratory pathogens may represent a competitive strategy in the sinus and warrants further investigation.

Current trends in topical therapies for chronic rhinosinusitis: update and literature review

INTRODUCTION

Chronic rhinosinusitis (CRS) affects millions of patients worldwide. The disease is multifactorial with influences including anatomic factors, immunological disturbances, and altered sinonasal microbiome. Although oral medications are effective in controlling some symptoms, they are associated with side effects and long-term use is not ideal. Thus, topical therapies have emerged as an alternative delivery method for localized, high-concentration medication with less side effects. Areas covered: This is a review of the various topical therapies available or under investigation for the management of CRS. Common medications such as saline, steroids, and antimicrobials will be discussed. Furthermore, additives including manuka honey, xylitol, surfactant, N-chlorotaurine, Dead Sea salt, and sodium hyaluronate will be addressed. Innovations in topical therapies, such as drug-eluting biomaterials and photodynamic therapy, will also be reviewed. Expert opinion: Although topical therapies provide a high dose of active substance at the site of disease, their efficacy in CRS is not clear. Topical saline and intranasal steroids appear to consistently demonstrate therapeutic benefits. However, other topical medications require further investigation to determine long-term clinical efficacy and safety. A better understanding of their effects on the sinonasal mucociliary system is needed before they become the standard of care in CRS.