Biofilms correlate with TH1 inflammation in the sinonasal tissue of patients with chronic rhinosinusitis

Receptors Involved in COVID-19-Related Anosmia: An Update on the Pathophysiology and the Mechanistic Aspects

Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.

Periprosthetic joint infection and immunity: Current understanding of host-microbe interplay

Periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. Even with current treatments, failure rates are unacceptably high with a 5-year mortality rate of 26%. Majority of the literature in the field has focused on development of better biomarkers for diagnostics and treatment strategies including innovate antibiotic delivery systems, antibiofilm agents, and bacteriophages. Nevertheless, the role of the immune system, our first line of defense during PJI, is not well understood. Evidence of infection in PJI patients is found within circulation, synovial fluid, and tissue and include numerous cytokines, metabolites, antimicrobial peptides, and soluble receptors that are part of the PJI diagnosis workup. Macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs) are initially recruited into the joint by chemokines and cytokines produced by immune cells and bacteria and are activated by pathogen-associated molecular patterns. While these cells are efficient killers of planktonic bacteria by phagocytosis, opsonization, degranulation, and recruitment of adaptive immune cells, biofilm-associated bacteria are troublesome. Biofilm is not only a physical barrier for the immune system but also elicits effector functions. Additionally, bacteria have developed mechanisms to evade the immune system by inactivating effector molecules, promoting killing or anti-inflammatory effector cell phenotypes, and intracellular persistence and dissemination. Understanding these shortcomings and the mechanisms by which bacteria can subvert the immune system may open new approaches to better prepare our own immune system to combat PJI. Furthermore, preoperative immune system assessment and screening for dysregulation may aid in developing preventative interventions to decrease PJI incidence.

Current evidence of biofilms in chronic rhinosinusitis- a microbiological perspective

INTRODUCTION

Chronic rhinosinusitis (CRS) is characterized by inflammation of the paranasal sinus mucosa persisting for more than 12 weeks. This condition is associated with reduced quality-of-life and causes a high direct and indirect economic burden. Several pathogenic factors have been attributed to CRS, including bacterial and fungal biofilms on the sinonasal mucosa. Biofilms are well-established contributors to recalcitrance to treatment in other chronic inflammatory mucosal conditions such as cystic fibrosis and otitis media.

AREAS COVERED

This review will present an overview of the role of biofilms in CRS, including the evidence for biofilms being present on the sinonasal mucosa and their implications for disease severity. Furthermore, the interactions between biofilms and host-mediated immune factors are explored.

EXPERT OPINION

The eradication of biofilms has been a focus of research shortly after their recognition as a cause of disease. The currently available methodologies for identifying biofilms on mucosal surfaces are not sufficiently well-developed to be used in a clinical setting. A more accurate, cheaper, faster approach for biofilm detection is necessary, and molecular techniques may provide the possibility for this.

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.

A Precision Medicine Approach to Rhinitis Evaluation and Management

PURPOSE OF REVIEW

Precision medicine (PM) represents a new paradigm in disease diagnosis, prevention, and treatment. The PM approach focuses on the characterization of different phenotypes and pathogenic pathways in order to allow the selection of specific biomarkers that will be useful in disease management. Rhinitis is a highly prevalent and heterogeneous disease, both in terms of underlying endotypes and clinical presentations. Therefore, to apply the PM principles to the various rhinitis subtypes rise as a meaningful strategy to improve evaluation and treatment.

RECENT FINDINGS

The technology of recombinant allergens has allowed molecular characterization of IgE reactivity of specific individual components of allergenic extracts. Recently published and ongoing clinical trials based on component resolved diagnosis (CRD) bring more precision to allergen immunotherapy for allergic rhinitis. Monoclonal antibodies against various cytokines involved in inflammatory allergic and nonallergic rhinitis endotypes show promissory results.

SUMMARY

Better understanding of pathogenic pathways together with an accurate phenotype classification of patients presented with rhinitis symptoms contributes to point out clinical usefulness of biomarkers and other diagnostic tools, which leads to more accurate environmental control measures, personalized pharmacologic options, and new biological therapy developments.

High-risk Staphylococcus aureus transmission in the operating room: A call for widespread improvements in perioperative hand hygiene and patient decolonization practices

BACKGROUND

Increased awareness of the epidemiology of transmission of pathogenic bacterial strain characteristics may help to improve compliance with intraoperative infection control measures. Our aim was to characterize the epidemiology of intraoperative transmission of high-risk Staphylococcus aureus sequence types (STs).

METHODS

S aureus isolates collected from 3 academic medical centers underwent whole cell genome analysis, analytical profile indexing, and biofilm absorbance. Transmission dynamics for hypertransmissible, strong biofilm-forming, antibiotic-resistant, and virulent STs were assessed.

RESULTS

S aureus ST 5 was associated with increased risk of transmission (adjusted incidence risk ratio, 6.67; 95% confidence interval [CI], 1.82-24.41; P = .0008), greater biofilm absorbance (ST 5 median absorbance ± SD, 3.08 ± 0.642 vs other ST median absorbance ± SD, 2.38 ± 1.01; corrected P = .021), multidrug resistance (odds ratio, 7.82; 95% CI, 2.19-27.95; P = .002), and infection (6/38 ST 5 vs 6/140 STs; relative risk, 3.68; 95% CI, 1.26-10.78; P = .022). Provider hands (n = 3) and patients (n = 4) were confirmed sources of ST 5 transmission. Transmission locations included provider hands (n = 3), patient skin sites (n = 4), and environmental surfaces (n = 2). All observed transmission stories involved the within-case mode of transmission. Two of the ST 5 transmission events were directly linked to infection.

CONCLUSIONS

Intraoperative S aureus ST 5 isolates are hypertransmissible and pathogenic. Improved compliance with hand hygiene and patient decolonization may help to control the spread of these dangerous pathogens.

Inflammatory immune response in rabbits with Staphylococcus aureus biofilm-associated sinusitis

Background

Staphylococcus aureus is the most commonly isolated bacterium from patients with surgically recalcitrant chronic rhinosinusitis (CRS). Understanding the immune responses to S aureus biofilms will provide insights into how the host response may be manipulated by therapeutic agents to improve the chances of successfully preventing and treating these infections. In this study, we investigated the inflammatory immune response in a rabbit model of S aureus biofilm–related sinusitis by analyzing the levels of some major inflammatory cytokines.

Methods

Eighteen New Zealand white rabbits were randomly divided into 3 groups: a blank‐control group; a negative‐control group; and a model group. Four weeks after the biofilm‐associated sinusitis models were established, the sinus mucosa was harvested and examined using hematoxylin‐eosin (H&E) staining, scanning electron microscopy (SEM), reverse transcription polymerase chain reaction (RT‐PCR), and western blotting. The expression levels of inflammatory cytokines were analyzed statistically.

Results

Interleukin (IL)‐1β, IL‐8, and tumor necrosis factor (TNF)‐α expression levels were significantly higher in the model group than in the blank‐control group (p < 0.05); mRNA levels were increased by 1600%, 230%, and 130%, respectively, and the protein levels were increased by 180%, 100%, and 100%, respectively. In contrast, IL‐4 and IL‐5 mRNA levels were reduced by 44% and 70%, respectively, compared with the blank‐control group (p < 0.05).

Conclusion

S aureus biofilms in the rabbit maxillary sinus mucosa were associated with increased IL‐1β, IL‐8, and TNF‐α expression, and decreased IL‐4 and IL‐5 expression.

Safety and efficacy of Galgeun-tang-ga-cheongung-sinyi, a herbal formula, for the treatment of chronic rhinosinusitis: A study protocol for a randomized controlled trial

INTRODUCTION

A herbal formula, Galgeun-tang-ga-cheongung-sinyi (GGTCS), is traditionally used for the treatment of rhinosinusitis in East Asian countries. However, there is a dearth of clinical evidence supporting the effects of this medication. Here, we describe the protocol for a randomized controlled study designed to investigate the efficacy and safety of GGTCS for the treatment of chronic rhinosinusitis (CRS).

METHODS AND ANALYSIS

To investigate the clinical efficacy and safety of GGTCS for the treatment of CRS, a randomized, double-blind, placebo-controlled, parallel group, clinical trial has been designed. A total of 58 participants with CRS will be recruited and randomly allocated to a GGTCS or placebo group in a 1:1 ratio. The participants will be administered GGTCS or placebo granules 3 times a day for 8 weeks. Data will be collected from the participants at baseline and at 1, 2, 4, and 8 weeks after random allocation. The primary outcome measure will be the mean change in the Sino-Nasal Outcome Test-22 score from baseline to 8 weeks. The secondary outcomes will include the Total Nasal Symptom Score, EuroQoL 5 Dimensions 5 Levels score, Nasal Endoscopy Index, Lund-Mackay score, and total serum immunoglobulin E level.

DISCUSSION

The key elements for conducting a high-quality randomized clinical trial have been addressed in this protocol. In summary, the findings of this study are expected to provide a base for large-scale randomized controlled trials to confirm the safety and efficacy of GGTCS for the treatment of CRS and may consequently serve to improve future treatment strategies for this condition.

TRIAL REGISTRATION

This study has been registered at the Korean National Clinical Trial Registry, Clinical Research Information Service (KCT0002835).

Bacterial Ball as an Unusual Finding in Patients With Chronic Rhinosinusitis

OBJECTIVES

Pathophysiology of chronic rhinosinusitis (CRS) is very complex and has not yet been clearly understood. To date, various factors have been researched to have relations with the pathogenesis of CRS, such as superantigens and biofilms. Recently, we found an unusual pathological finding in patients with CRS, and we called this new entity as bacteria ball (or bioball). In this study, we analyze the clinical characteristics of bacteria ball occurred in CRS.

METHODS

This study enrolled consecutive 247 patients with CRS who underwent functional endoscopic sinus surgery from January 2015 to August 2016. The diagnosis of bacterial ball was made when negative in Gomori-methenamine-silver stain and positive in Gram stain. Histologically, bacterial ball was defined as acellular mucous materials with bacterial colonies and inflammatory cell infiltrates. We compared clinical data and computed tomography (CT) findings between fungal and bacterial balls.

RESULTS

Six cases (2.4%) of CRS were confirmed histologically as bacterial ball. Most of them were found in the maxillary sinus of CRS without nasal polyposis (66.7%). Bacterial ball was green or brown colored materials similar to fungal ball which was harder and tightly adherent to the antral mucosa. Compared to fungal ball, patients with bacterial ball showed significantly less peripheral eosinophils (P=0.011) and calcification in CT scans (P=0.003).

CONCLUSION

Bacterial ball is unusual findings occurred in patient with CRS which is different from fungal ball and biofilm. For diagnosis of bacterial ball, Gram stain is essentially required to identify bacterial colonies. Bacterial ball might appear to be evidence of a new strategy for living in the paranasal sinuses.

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.

A comprehensive review of the nasal microbiome in chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) has been known as a disease with strong infectious and inflammatory components for decades. The recent advancement in methods identifying microbes has helped implicate the airway microbiome in inflammatory respiratory diseases such as asthma and COPD. Such studies support a role of resident microbes in both health and disease of host tissue, especially in the case of inflammatory mucosal diseases. Identifying interactive events between microbes and elements of the immune system can help us to uncover the pathogenic mechanisms underlying CRS. Here we provide a review of the findings on the complex upper respiratory microbiome in CRS in comparison with healthy controls. Furthermore, we have reviewed the defects and alterations of the host immune system that interact with microbes and could be associated with dysbiosis in CRS.

Fifty Years of Chronic Rhinosinusitis in Children: The Accepted, the Unknown, and Thoughts for the Future

Chronic sinusitis is an often-used term in both lay and medical circumstances. In children, it has significant but largely undefined healthcare costs. Chronic rhinosinusitis (CRS) in children has well demarcated time periods and symptoms, although the actual pathway from normal sinus to CRS is not well understood. There is reasonable consensus as to the standards for diagnosis, the selection of a first-round antibiotic, and length of treatment. However, no recent prospective studies of antibiotics are available. Areas of continued speculation include the following: the microbiome of pediatric CRS, the best use of standard imaging, alternative antibiotic selection, ancillary therapy, and treatment of refractory CRS. In addition, older adolescents can present with a more adult-oriented CRS with or without polyps, suggesting a broader spectrum of disease than is commonly recognized. An accounting of the accepted elements of pediatric rhinosinusitis, as well as areas for future research, is emphasized in this review and, where appropriate, suggestions for potential investigations are offered.

Rhinitis Subtypes, Endotypes, and Definitions

Rhinitis is often seen as posing a small burden. However, rhinitis is a complex disease that is underpinned by a plethora of different mechanisms and causes. Rhinitis is frequently associated with other comorbid conditions but, by itself, is a source of considerable morbidity for patients and creates a significant financial burden on health systems worldwide. This article approaches this condition from both a phenotypic and mechanistic standpoint, focusing on the complexity of characterizing these subtypes. Developing a clearer demarcation of the currently obscure rhinitis phenotypes and endotypes will substantially improve their future prevention and treatment.

Biofilms in chronic rhinosinusitis: what is new and where next?

Background:

Chronic rhinosinusitis is a common, heterogeneous condition. An effective means of mitigating disease in chronic rhinosinusitis patients remains elusive. A variety of causes have been implicated, with the biofilm theory gaining increasing prominence.

Objective:

This article reviews the literature on the role of biofilms in chronic rhinosinusitis, in terms of pathophysiology and with regard to avenues for future treatment.

Methods:

A systematic review of case series was performed using databases with independently developed search strategies, including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane library, and Zetoc, in addition to conference proceedings and a manual search of literature, with the last search conducted on 18 January 2014. The search terms included the following, used in various combinations to maximise the yield of articles identified: ‘biofilms’, ‘chronic rhinosinusitis’, ‘DNase’, ‘extracellular DNA’ and ‘biofilm dispersal’.

Results:

The existing evidence lends further support for the role of biofilms (particularly the Staphylococcus aureus phenotype) in more severe, recalcitrant disease and poorer surgical outcomes.

Conclusion:

Multimodality treatment, with a shift in paradigm to incorporate anti-biofilm strategies, is likely to form the mainstay of future recalcitrant chronic rhinosinusitis management.

Bacterial biofilms are associated with inflammatory cells infiltration and the innate immunity in chronic rhinosinusitis with or without nasal polyps

To investigate the role of bacterial biofilms in the pathogenesis of chronic rhinosinusitis, we applied scanning electron microscopy to detect bacterial biofilms, immunohistochemical and hemotoxylin-eosin staining to identify the types of inflammatory cells infiltration, and real-time PCR array analysis to evaluate the innate immune responses to bacteria biofilms. Biofilms were found in 14 of 19 (73.7%) of CRSwNP (chronic rhinosisusitis with nasal polyps), 11 of 15 (73.3%) of CRSsNP (chronic rhinosisusitis without nasal polyps), and none of biofilms were found in 13 normal controls. T helper lymphocytes, cytotoxic T lymphocytes, and neutrophils were the most frequently observed immune cells. The inflammatory cells did not reveal any significant differences in CRSwNP between with biofilms and without biofilms. CRSsNP with biofilms had significantly more neutrophils than CRSsNP without biofilms, and it was inclined to Th1 inflammatory response. Fifty and fifty-one genes were upregulated respectively in CRSwNP and CRSsNP with biofilms. Twenty genes were upregulated separately when comparing biofilms-positive CRSwNP with biofilms-positive CRSsNP. CRSwNP and CRSsNP with biofilms had different types of inflammatory cells infiltration and characteristic changes of the innate immunity. Further research about the direct role of bacterial biofilms in the pathogenesis of CRS will provide a new target for CRS.

Sinonasal microbiome sampling: a comparison of techniques

Background

The role of the sino-nasal microbiome in CRS remains unclear. We hypothesized that the bacteria within mucosal-associated biofilms may be different from the more superficial-lying, free-floating bacteria in the sinuses and that this may impact on the microbiome results obtained. This study investigates whether there is a significant difference in the microbiota of a sinonasal mucosal tissue sample versus a swab sample.

Methods

Cross-sectional study with paired design. Mucosal biopsy and swab samples were obtained intra-operatively from the ethmoid sinuses of 6 patients with CRS. Extracted DNA was sequenced on a Roche-454 sequencer using 16S-rRNA gene targeted primers. Data were analyzed using QIIME 1.8 software package.

Results

At a maximum subsampling depth of 1,100 reads, the mean observed species richness was 33.3 species (30.6 for swab, versus 36 for mucosa; p > 0.05). There was no significant difference in phylogenetic and non-phylogenetic alpha diversity metrics (Faith’s PD_Whole_Tree and Shannon’s index) between the two sampling methods (p > 0.05). The type of sample also had no significant effect on phylogenetic and non-phylogenetic beta diversity metrics (Unifrac and Bray-Curtis; p > 0.05).

Conclusion

We observed no significant difference between the microbiota of mucosal tissue and swab samples. This suggests that less invasive swab samples are representative of the sinonasal mucosa microbiome and can be used for future sinonasal microbiome studies.

Bitter and sweet taste receptors regulate human upper respiratory innate immunity

Bitter taste receptors (T2Rs) in the human airway detect harmful compounds, including secreted bacterial products. Here, using human primary sinonasal air-liquid interface cultures and tissue explants, we determined that activation of a subset of airway T2Rs expressed in nasal solitary chemosensory cells activates a calcium wave that propagates through gap junctions to the surrounding respiratory epithelial cells. The T2R-dependent calcium wave stimulated robust secretion of antimicrobial peptides into the mucus that was capable of killing a variety of respiratory pathogens. Furthermore, sweet taste receptor (T1R2/3) activation suppressed T2R-mediated antimicrobial peptide secretion, suggesting that T1R2/3-mediated inhibition of T2Rs prevents full antimicrobial peptide release during times of relative health. In contrast, during acute bacterial infection, T1R2/3 is likely deactivated in response to bacterial consumption of airway surface liquid glucose, alleviating T2R inhibition and resulting in antimicrobial peptide secretion. We found that patients with chronic rhinosinusitis have elevated glucose concentrations in their nasal secretions, and other reports have shown that patients with hyperglycemia likewise have elevated nasal glucose levels. These data suggest that increased glucose in respiratory secretions in pathologic states, such as chronic rhinosinusitis or hyperglycemia, promotes tonic activation of T1R2/3 and suppresses T2R-mediated innate defense. Furthermore, targeting T1R2/3-dependent suppression of T2Rs may have therapeutic potential for upper respiratory tract infections.

Host-microbial interactions in patients with chronic rhinosinusitis

There has been considerable investigation of host-microbial interactions in patients with chronic rhinosinusitis (CRS) in hopes of elucidating mechanisms of disease and better treatment. Most attention has been paid to bacterial infection and potential underlying defects in innate immunity. Bacterial biofilm is present in most patients with CRS undergoing surgical intervention, and its presence is associated with more severe disease and worse surgical outcomes. A role for viral or fungal infection in patients with CRS is less clear. There is no evidence for a primary defect in mucociliary clearance in most patients with CRS. Decreased levels of certain antimicrobial proteins, most notably lactoferrin, have been found in sinus secretions, whereas levels of other antimicrobial proteins have been found to be normal. No primary defects in Toll-like receptors have been found in patients with CRS, although a 50% reduced expression of Toll-like receptor 9 was reported in patients with recalcitrant nasal polyps. A polymorphism in a bitter taste receptor was recently associated with refractory CRS and persistent Pseudomonas aeruginosa infection. A downregulation of innate immunity by maladaptive T_H2 tissue inflammation has also been described in patients with recalcitrant nasal polyps, suggesting a link to persistent infection. To date, an effective means of restoring host-microbial balance and mitigating disease in patients with CRS remains elusive.

Correlation between bacterial biofilms and osteitis in patients with chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

Bacterial biofilms (BBF) and osteitis are potential contributors to the local inflammatory load in chronic rhinosinusitis (CRS). This study investigated the relationship between BBF and osteitis status in CRS patients.

STUDY DESIGN

Prospective cohort study.

METHODS

Eighty-four CRS patients undergoing endoscopic sinus surgery and 22 control patients were enrolled in this study. Mucosal and bony samples from ethmoid sinus were obtained for confocal scanning laser microscopy and microscopic examination. Biofilm volume (BV), biofilm score (BS), histopathologic bony grade, Global Osteitis Scoring Scale (GOSS) score, and Hounsfield unit (HU) value on computed tomography were recorded. Associations between these parameters describing BBF and osteitis were assessed.

RESULTS

The histopathologic bony grade 2 (0-3) versus 0 (0-3) (P < 0.001), GOSS score 4.5 (0-31) versus 0 (0-26) (P = 0.014) and HU value 431.5 (310-509) versus 354 (288-499) (P < 0.001) in patients with BBF were greater than those without BBF. The bony grade (r = 0.683, P < 0.001 and r = 0.664, P < 0.001), GOSS score (r = 0.314, P = 0.004 and r = 0.312, P = 0.004), and HU value (r = 0.539, P < 0.001 and r = 0.520, P < 0.001) were significantly increased with higher BV and BS.

CONCLUSION

A total of 84.8% of the bone underlying mucosa with BBF had some form of osteitis in ethmoid sinus, and approximately 46.4% of CRS patients were from a subgroup with both BBF and osteitis. The volume of BBF correlated well with severity of osteitis in CRS patients.

Interferon gamma causes olfactory dysfunction without concomitant neuroepithelial damage

BACKGROUND

Olfactory loss is a debilitating symptom of chronic rhinosinusitis (CRS). The pathophysiology of inflammatory olfactory dysfunction likely involves both conductive and sensorineural components. To study the interaction of CRS-associated inflammatory cytokines with the olfactory epithelium (OE), a transgenic mouse model was developed that allows temporally-controlled local gene expression. Interferon-gamma (IFN-γ) is a prototypical T helper 1 (Th1) cytokine linked to nonpolypoid CRS (CRSsNP), as well as sinonasal viral and bacterial infections. In this study, the effects of chronic IFN-γ expression on olfactory histology and function were investigated.

METHODS

IFN-γ secretion by olfactory sustentacular cells was induced in the transgenic mouse. Viability and gross behavior were unaffected. Mice were euthanized after 6 weeks of IFN-γ expression, and olfactory tissue was studied by histology, immunohistochemistry, and electro-olfactography (EOG). Findings were compared with uninduced littermates.

RESULTS

IFN-γ expression did not result in alteration of the normal histologic architecture of the neuroepithelium or lamina propria. However, EOG recordings demonstrated a significant decrease in odorant responses after IFN-γ expression. In addition, a marked increase in submucosal CD45-positive cells was observed, the majority of which were CD3-positive and CD4-positive lymphocytes.

CONCLUSION

Chronic IFN-γ expression in the mouse OE results in diminished odorant responsiveness, despite the absence of inflammatory tissue damage. This suggests a direct effect of IFN-γ on olfactory neuron function that may underlie olfactory loss in CRSsNP or viral infections. The infiltration of submucosal lymphocytes raises the possibility that other downstream cytokines also contribute to olfactory dysfunction.

Effects of intranasal steroid treatment on the presence of biofilms in non-allergic patients with chronic rhinosinusitis with nasal polyposis

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal application of corticosteroids (INCS) is a reliable option in the management of CRSwNP. INCS medication has been suspected to influence the presence and thickness of microbial biofilms and inflammatory cell patterns in CRSwNP. Two series of identical nasal polyps obtained from non-allergic patients with CRSwNP (n = 56), who underwent endoscopic sinus surgery (ESS), were processed to hematoxylin-eosin (H.E.) and Gram staining, respectively. Patients were recruited into three groups. Group A (n = 21) consisted of patients with continuous preoperative INCS treatment. In group B (n = 17), patients were never treated by INCS, while in group C (n = 18) INCS medication was stopped at least 6 months before ESS. Biofilm positivity varied from 76.4 to 88.8% in different subject groups. These values and average thickness of biofilms did not reach statistically significant levels (Mann-Whitney's U probe, p > 0.05) in different patient groups. In contrast, microscopic pattern and numbers of predominant inflammatory cell populations displayed obvious differences according to INCS treatment (Mann-Whitney's U probe, p < 0.001). According to these observations, INCS treatment does not affect the presence and thickness of microbial biofilms in CRSwNP. In contrast, it has significant effects on the pattern of inflammatory cells infiltrating the subepithelial layer, which might result in beneficially altered extracellular matrix production and cytokine release.

Role of bacterial and fungal biofilms in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a very common condition that remains poorly understood from a pathogenic standpoint. Recent interest has been sparked by a potential role for biofilms in this process, with a significant body of evidence implicating them in inciting sinonasal inflammation. Biofilms are clearly present on the sinus mucosa of CRS patients, and their presence there is associated with severe disease characteristics and surgical recalcitrance. We are beginning to understand the importance of the species within these biofilms, but there may be other as-yet-unidentified factors at play in influencing disease outcomes. Recent exciting research has emerged documenting the immune response to the presence of biofilms-research that will ultimately solidify the nature and extent of the contribution of biofilms in CRS pathogenesis. Future research should focus on evidence-based antibiofilm treatments with reference to efficacy and timing of treatment.

Subclassification of chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

There are variants of chronic rhinosinusitis (CRS). Therefore, the objectives of this study were to phenotype the subclasses of CRS as well as characterize their polyps with histology and cellular-intracellular biomarkers.

STUDY DESIGN

Prospective case-control study.

METHODS

Demographic data, quality-of-life (QoL) questionnaires, nasal endoscopy (NE), and computed tomography (CT) scores were obtained. CRS was divided into seven subclasses: aspirin-exacerbated respiratory disease (AERD), asthmatic sinusitis with and without allergy, nonasthmatic sinusitis with and without allergy, allergic fungal sinusitis (AFS), and cystic fibrosis (CF). Histopathologic and immunohistochemistry of nasal polyps were recorded. CD3, CD4, CD8, CD19, CD45, and CD56 data were collected. Interleukin (IL)4, IL5, IL13, IL17, and interferon (IFN)-γ were measured.

RESULTS

Eight-four subjects were in this study. Two QoL questionnaires were inadequate at distinguishing the control group from CRS. NE and CT were able to differentiate between the control group and all CRS subclasses (P<.01). Asthmatic sinusitis, AERD, and AFS had high NE and CT scores, nasal polyps, eosinophils, mast cell, and hypercellularity. Asthmatic sinusitis, nonasthmatic sinusitis, and AERD had higher CD4 cells than control group (P<.05). Even though asthmatic sinusitis and AFS are mediated by Th2, AFS had differing levels of Th2 cytokines. Each nonasthmatic sinusitis had purulence and low CT score. Each nonasthmatic sinusitis had higher CD4 cells and IFN-γ than control (P<.05). CF is associated with purulence, high CT score, high polymorphonuclear leukocytes, high plasma cells, and high mast cells.

CONCLUSIONS

Well-characterized and distinct groups of CRS have been defined for targeted treatment and research studies.

The presence of CD209 expressing dendritic cells correlates with biofilm positivity in chronic rhinosinusitis with nasal polyposis

Biofilm-positive cases of chronic rhinosinusitis with nasal polyposis (CRSwNP) may form a separate clinical entity, which is characterized by high recurrence rates and resistance against different therapeutic strategies. This can be explained by a special immunologic phenotype. Biofilm existence has been supposed to correlate with increased amount of dendritic cells that are responsible for antigen presentation in CRSwNP. A total of 20 patients with CRSwNP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of ten patients undergoing septoplasty without CRSwNP. Three series of individual nasal polyps and control specimens were processed to hematoxylin-eosin (HE) and Gram staining and to CD209-specific immunofluorescent assay, respectively. Biofilm was detected in 13 of 20 patients (65 %) with CRSwNP and in none of the ten negative controls. The subepithelial layer of biofilm-positive nasal polyps displayed a statistically significant (p < 0.001) increase in the numbers of CD209-expressing dendritic cells compared to biofilm-negative specimens. It was found that biofilm detectability showed strong correlation to the architecture of respiratory mucosa and to the dominant inflammatory cell type of the subepithelial layer. Persisting bacterial biofilms may affect the type of antigen presentation and consecutive immune reactions in the subepithelial layer of nasal mucosa. This phenomenon may result in different inflammatory pathways with specific cytokine profile compared to biofilm-negative cases. Co-existence of bacterial biofilms and dominant pattern of dendritic cells suggest a biofilm-associated immunologic phenotype in CRSwNP. This can explain the mucosal changes, functional disorders and therapy resistance featuring CRSwNP.

Topical gel therapy for sinonasal polyposis in Samter's triad: preliminary report

OBJECTIVES

Rhinosinusitis and polyposis are difficult to treat in patients with Samter's triad; they commonly recur despite sinus surgery, antibiotics, and/or nasal steroids. The present study assesses the efficacy of a multimodal regimen that includes topical corticosteroids and antibiotics delivered through a hydroxyethyl cellulose gel and by nebulization.

METHODS

Eleven patients with Samter's triad who had polyposis and rhinosinusitis that recurred despite endoscopic sinus surgery were treated with a 6-week course of multimodal topical therapy consisting of a hydroxyethyl cellulose gel that releases corticosteroids and antibiotics, topical nebulization of corticosteroids and antibiotics, saline solution rinses, and sinus debridement. Clinical outcomes were evaluated by Lund-Kennedy endoscopic and symptom scores. Histologic assessment was evaluated by hematoxylin and eosin staining before and after treatment.

RESULTS

Both Lund-Kennedy symptom and endoscopic scores showed.a progressive and statistically significant decline throughout the course of treatment, reaching at 6 weeks 42% of the pretreatment values (p = 0.005) for the Lund-Kennedy symptom score and 34% (p = 0.002) for the endoscopic score, respectively; however, the significance of the improvement was lost with time.

CONCLUSIONS

Topical gel therapy improves clinical symptoms, endoscopic findings, and sinus membrane histologic features in patients with refractory Samter's triad, but the improvement is transient, suggesting that a longer therapeutic period might be needed.

T2R38 taste receptor polymorphisms underlie susceptibility to upper respiratory infection

Innate and adaptive defense mechanisms protect the respiratory system from attack by microbes. Here, we present evidence that the bitter taste receptor T2R38 regulates the mucosal innate defense of the human upper airway. Utilizing immunofluorescent and live cell imaging techniques in polarized primary human sinonasal cells, we demonstrate that T2R38 is expressed in human upper respiratory epithelium and is activated in response to acyl-homoserine lactone quorum-sensing molecules secreted by Pseudomonas aeruginosa and other gram-negative bacteria. Receptor activation regulates calcium-dependent NO production, resulting in stimulation of mucociliary clearance and direct antibacterial effects. Moreover, common polymorphisms of the TAS2R38 gene were linked to significant differences in the ability of upper respiratory cells to clear and kill bacteria. Lastly, TAS2R38 genotype correlated with human sinonasal gram-negative bacterial infection. These data suggest that T2R38 is an upper airway sentinel in innate defense and that genetic variation contributes to individual differences in susceptibility to respiratory infection.

Modular microfluidic system as a model of cystic fibrosis airways

A modular microfluidic airways model system that can simulate the changes in oxygen tension in different compartments of the cystic fibrosis (CF) airways was designed, developed, and tested. The fully reconfigurable system composed of modules with different functionalities: multichannel peristaltic pumps, bubble traps, gas exchange chip, and cell culture chambers. We have successfully applied this system for studying the antibiotic therapy of Pseudomonas aeruginosa, the bacteria mainly responsible for morbidity and mortality in cystic fibrosis, in different oxygen environments. Furthermore, we have mimicked the bacterial reinoculation of the aerobic compartments (lower respiratory tract) from the anaerobic compartments (cystic fibrosis sinuses) following an antibiotic treatment. This effect is hypothesised as the one on the main reasons for recurrent lung infections in cystic fibrosis patients.

Tumor necrosis factor-α receptor expression correlates with mucosal changes and biofilm presence in chronic rhinosinusitis with nasal polyposis

OBJECTIVES/HYPOTHESIS

Biofilms might play a potential role in the pathogenesis and high recurrence rate of chronic rhinosinusitis with nasal polyposis (CRSwNP). Biofilm persistence has been thought to correlate with epithelial damage, subepithelial inflammatory cell infiltration, and tumor necrosis factor-α receptor (TNFR) expression in CRSwNP.

STUDY DESIGN

Case-control experimental study.

METHODS

A total of 36 patients with CRSwNP undergoing endoscopic sinus surgery were analyzed. The negative control group consisted of eight patients undergoing septoplasty for nasal obstruction without CRSwNP. The nasal polyps and inferior turbinate mucosa samples applied as negative controls were processed by hematoxylin-eosin (HE) and Gram staining and TNFR-I and TNFR-II-specific immunofluorescent assay.

RESULTS

Biofilm was detected in 29 of 36 patients with CRSwNP and in none of the eight negative controls. Staining by HE showed strong correlation with the results of Gram staining protocol. In the biofilm-positive cases, TNFR-I and TNFR-II displayed homogeneous pattern of significantly increased epithelial expression compared to the biofilm-negative nasal polyps. In cases of biofilm absence, the expression pattern of TNF-α receptors was characterized by increased TNFR-II-specific immunoreaction. It was found that biofilm detectability corresponded to the integrity of nasal epithelium and to the dominant inflammatory cell type of the subepithelial layer.

CONCLUSIONS

Persisting biofilms might increase the epithelial sensitivity against TNF-α that result in epithelium destruction. Coexistence of biofilms and increased TNFR expression might explain the inflammatory mucosal changes, functional disorders, and therapy resistance featuring CRSwNP.

Biofilm formation and Toll-like receptor 2, Toll-like receptor 4, and NF-kappaB expression in sinus tissues of patients with chronic rhinosinusitis

BACKGROUND

Bacterial biofilm formation is associated with chronic rhinosinusitis (CRS). However, how bacterial biofilms are related to innate immune response in patients is poorly understood. The aim of this study was to evaluate the prevalence of biofilms in CRS patients and investigate the biofilm-related Toll-like receptor (TLR) and downstream NF-kappaB expression in sinus tissues of patients with CRS.

METHODS

A total of 31 CRS patients and 11 control patients with other diseases undergoing endoscopic sinus surgery were recruited consecutively. Their random sinonasal tissue specimens were examined for the formation of biofilms by scanning electron microscopy. The relative levels of TLR2, TLR4, and NF-kappaB expression in those sinus tissues were determined by quantitative real-time reverse-transcriptase polymerase chain reaction and immunohistochemistry.

RESULTS

Bacterial biofilms were detected in 20 of 31 samples from CRS patients but not in a single sample from control patients. The relative levels of TLR2, TLR4, and NF-kappaB expression in sinus tissues from CRS patients were significantly higher than that of controls, and the relative levels of TLR2 and NF-kappaB, but not TLR4, in biofilm-positive sinus tissues were significantly higher than that in biofilm-negative tissues of those CRS patients.

CONCLUSION

Our data indicated that bacterial biofilms were associated with higher levels of TLR2 and NF-kappaB in the majority of sinus tissues from patients with CRS.

Adaptive immune responses in Staphylococcus aureus biofilm-associated chronic rhinosinusitis

BACKGROUND

The etiopathogenesis of chronic rhinosinusitis (CRS) is currently an area of intense debate. Recently, biofilms have been proposed as a potential environmental trigger in this disease. In particular, Staphylococcus aureus biofilms appear to be a predictor of severe disease recalcitrant to current treatment paradigms. However, direct causal links between biofilms and host immune activation are currently lacking. This study aimed to document both the adaptive immune responses that characterize S. aureus biofilm-associated CRS and the relative contributions of staphylococcal superantigens and S. aureus biofilms in the inflammatory make-up of this disease.

METHODS

A total of 53 disease subjects and 15 controls were recruited. Sinonasal mucosa was collected for the determination of S. aureus and Haemophilus influenzae biofilms and presence of total and superantigen-specific IgE and for the measurement of cytokines that characterize the T-helper pathways.

RESULTS

Staphylococcus aureus biofilms and superantigens are significantly associated in CRS patients, suggesting the biofilm may be a nidus for superantigen-eluting bacteria. The presence of S. aureus biofilms is associated with eosinophilic inflammation, across the spectrum of CRS, on the back of a T-helper(2) skewing of the host's adaptive immune response (elevated Eosinophilic Cationic Protein and IL-5). This can be distinguished from the superantigenic effect resulting in the induction of IgE.

CONCLUSION

This study provides novel evidence of a link between S. aureus biofilms and skewing of the T-cell response toward the T-helper(2) pathway that is independent of superantigen activities. Further research is required to confirm the cause-effect relationship of this association.

Factors affecting bacterial biofilm expression in chronic rhinosinusitis and the influences on prognosis

PURPOSE

The purpose of the study was to investigate the expression of bacterial biofilm (BF) for chronic rhinosinusitis (CRS) and to find out factors affecting BF expression and the influences on its prognosis.

MATERIALS AND METHODS

All specimens were analyzed by a scanning electron microscope and bacterial cultivation from a panel of 93 patients with CRS, 20 with nasal septum deviation, and 17 with nasal bone fractures as the control group. Referring to the grade classification criteria from the sinusitis-specific questionnaire Sino-Nasal Outcome Test-20, patients were assessed preoperatively based on common clinical manifestations. Patients were followed up for condition improvement as assessed by visual analogue scale and nasal endoscopic examination.

RESULTS

In the experimental group, among all the patients, 3 were lost (lost 3.2%). Bacterial biofilm was positive in 64 (71.1%) of 90 patients. Mucosal cilia were observed in varying degrees of injury. Bacterial culture was positive in 60 (66.7%) patients. In the control group, no BF was found and no bacterium was cultured. Bacterial biofilm expression was correlated with the bacterial culture. The BF(+) patients' visual analogue scale scores 6 months and 1 year postoperation were lower than the BF(-) patients' scores (P < .05). The BF(+) patients' Lund-Kennedy scores at 6 months and 1 year postoperation were higher than the BF(-) patients' scores (P < .05).

CONCLUSIONS

Bacterial biofilm is involved in the pathogenesis of CRS and is associated with the bacterial culture. Bacterial biofilm has a certain impact on patients' prognosis.

Evaluation of bacterial adherence and biofilm arrangements as new targets in treatment of chronic rhinosinusitis

Several promising candidate drugs that target bacterial adherence and biofilm formation are being developed. Such hopeful drugs cannot be studied in chronic rhinosinusitis (CRS) without the evaluation of such virulence criteria in different forms of the disease with and without nasal polyposis (CRSwNP and CRSsNP). The aim of this study was to evaluate bacterial adherence, response to antibiotics and degree of accumulation of bacterial biofilms as new targets of treatment in CRSwNP and CRSsNP. Twenty CRS patients and 10 normal subjects with airway obstructing concha bullosa were prospectively enrolled in the present study. Scanning electron microscopy and cultures were performed on paranasal sinus tissue samples. Bacterial adherence tests using the tissue culture plate method were measured quantitatively. Strongly adherent bacteria were identified significantly in 6/9 (77%) cases of CRSsNP in comparison to 1/7 (14%) cases of CRSwNP. Strongly adherent bacteria that were sensitive to ciprofloxacin, vancomycin, and impenim were identified in 75% of the cultured coagulase positive staphylococci. A significant difference (P = 0.007) in the degree of accumulation of bacterial biofilms existed between the two groups. In CRSsNP, a more advanced stage of bacterial biofilms with strong bacterial adherence was observed which make them attractive targets for new drugs. In CRSwNP, lower stage bacterial biofilms with low bacterial adhesion were identified, which may help explain the low bacterial virulence in an environment of suboptimal, organizational arrangements.

Chronic rhinosinusitis as a multifactorial inflammatory disorder

Chronic rhinosinusitis (CRS) is a prevalent health condition characterized by sinonasal mucosal inflammation lasting at least 12 weeks. Heterogeneous in clinical presentation, histopathology, and therapeutic response, CRS represents a spectrum of disease entities with variable pathophysiology. Increased knowledge of cellular and molecular derangements in CRS suggests potential etiologies and targets for therapy. Microbial elements including fungi, staphylococcal enterotoxin, and biofilms have been implicated as inflammatory stimuli, along with airborne irritants and allergens. Defects in innate immunity have gained increased attention as contributors to the chronic inflammatory state. A combination of host susceptibility and environmental exposure is widely believed to underlie CRS, although direct evidence is lacking. Presently, without precise disease definitions and identifiable universal triggers, CRS pathogenesis is broadly described as multifactorial. Current research is beginning to unravel complex and diverse effects of chronic inflammation on sinonasal mucosal homeostasis, but dysfunctional pathways of inflammatory regulation and resolution require further elucidation.

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.

Biofilm detection in chronic rhinosinusitis by combined application of hematoxylin-eosin and gram staining

The pathomechanism of chronic rhinosinusitis with nasal polyposis (CRS/NP) seems to be unclear. Bacterial-, fungal- and combined biofilms might play a potential role in the pathogenesis of various inflammatory diseases and recently in CRS/NP. A prospective, blinded observational study was performed to confirm that the combination of conventional hematoxylin-eosin (HE) and Gram staining protocols could be used to detect bacterial and fungal biofilms in patients with CRS/NP. A total of 50 patients with CRS/NP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of 12 patients undergoing septoplasty for nasal obstruction without CRS/NP. The nasal polyps and inferior turbinate mucosa specimens applied as negative controls were processed to HE and Gram staining. Biofilm was detected in 44 of 50 patients with CRS/NP and in none of 12 negative controls. In our series, HE method showed an obvious correlation with the results of Gram staining and was allocated to be a good predictor of biofilm existence. It was found that the microscopic structure and thickness of biofilms were strongly associated with the integrity of nasal mucosa and with the characteristics of subepithelial cellular infiltration. This study confirmed the presence of bacterial and fungal biofilms on the surface of NPs obtained from patients with CRS. Since biofilms may affect the severity and recurrence rate of CRS treated by ESS they should be detected histologically. In conclusion, HE staining combined with Gram protocol is a robust and reliable method for the detection of bacterial and fungal biofilms in CRS/NP.

Biofilms in chronic rhinosinusitis with nasal polyps

OBJECTIVE

(1) Evaluate the presence of biofilms in patients with chronic sinusitis with nasal polyps (CRSwNP) and (2) investigate the association of biofilm presence and CRSwNP.

STUDY DESIGN

Cross-sectional study.

SETTING

University-based tertiary care center.

SUBJECTS AND METHODS

The study group consisted of 33 consecutive patients undergoing functional endoscopic sinus surgery for CRSwNP. The control group consisted of 27 control patients undergoing septoplasty for nasal obstruction without diagnosis of chronic sinusitis. Mucosal samples were harvested intraoperatively for scanning electron microscopic examination to determine biofilm presence. Statistical analysis was performed. For all statistical tests, P = .05 was considered significant.

RESULTS

Biofilms were found in 24 (72.7%) of the 33 patients with CRSwNP and in 13 (48.1%) of the 27 septoplasty patients (odds ratio = 2.87; 95% confidence interval, 0.98-8.42; P = .051).

CONCLUSION

(1) Biofilms were present in patients undergoing functional endoscopic sinus surgery for CRSwNP and also in controls without chronic sinusitis. This suggests that biofilms may not be sufficient to cause chronic sinusitis without other cofactors. Host factors could be the responsible for the pathogenesis of biofilms. (2) Although the prevalence of biofilms in patients with CRSwNP was not significantly different from that in the controls, the extremely wide 95% confidence interval, which is just below unity, suggests that a meaningful clinical difference may have been missed because of low statistical power. Further studies are necessary.

Murine immune response to a chronic Staphylococcus aureus biofilm infection

Staphylococcus aureus has reemerged as an important human pathogen in recent decades. Although many infections caused by this microbial species persist through a biofilm mode of growth, little is known about how the host's adaptive immune system responds to these biofilm infections. In this study, S. aureus cells adhered to pins in culture and were subsequently inserted into the tibiae of C57BL/6 mice, with an infecting dose of 2 × 10⁵ CFU. This model was utilized to determine local cytokine levels, antibody (Ab) function, and T cell populations at multiple time points throughout infection. Like human hosts, S. aureus implant infection was chronic and remained localized in 100% of C57BL/6 mice at a consistent level of approximately 10(7) CFU/gram bone tissue after day 7. This infection persisted locally for >49 days and was recalcitrant to clearance by the host immune response and antimicrobial therapy. Local inflammatory cytokines of the Th1 (interleukin-2 [IL-2], IL-12 p70, tumor necrosis factor alpha [TNF-α], and IL-1β) and Th17 (IL-6 and IL-17) responses were upregulated throughout the infection, except IL-12 p70, which dwindled late in the infection. In addition, Th1 Ab subtypes against a biofilm antigen (SA0486) were upregulated early in the infection, while Th2 Abs and anti-inflammatory regulatory T cells (Tregs) were not upregulated until later. These results indicate that early Th1 and Th17 inflammatory responses and downregulated Th2 and Treg responses occur during the development of a chronic biofilm implant infection. This unrestrained inflammatory response may cause tissue damage, thereby enabling S. aureus to attach and thrive in a biofilm mode of growth.

Decreased mucosal oxygen tension in the maxillary sinuses in patients with cystic fibrosis

BACKGROUND

Pseudomonas aeruginosa in the sinuses plays a role in the lungs in cystic fibrosis (CF) patients, but little is known about the sinus environment where the bacteria adapt. Anoxic areas are found in the lower respiratory airways but it is unknown if the same conditions exist in the sinuses.

METHODS

The oxygen tension (pO(2)) was measured, using a novel in vivo method, in the maxillary sinus in a group of 20 CF patients.

RESULTS

The CF patients had a significant lower pO(2) on the mucosa but not in the sinus lumen as compared with a control group of non-CF patients. Anoxic conditions were found in 7/39 (18%) of the sinuses from where we cultured P. aeruginosa, Stenotrophomonas maltophilia and/or coagulase negative staphylococci.

CONCLUSION

These findings support our hypothesis that P. aeruginosa can adapt or acclimate to the environment in the lungs, during growth in anoxic parts of the paranasal sinuses.