The role of bacterial biofilms and the pathophysiology of chronic rhinosinusitis

IL-17A facilitates type 2 inflammation in a modified eosinophilic chronic rhinosinusitis mouse model

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is predominantly characterized by nasal type 2 inflammation. The pathogenesis of this condition is complex. High levels of IL-17A are associated with eosinophil infiltration in some inflammatory diseases and contribute to the severity and insensitivity of corticosteroid therapy for chronic rhinosinusitis.

METHODS

In the first experiment, we constructed a modified ECRS mouse model using four groups of mice: phosphate-buffered saline (PBS)-sensitized and nasal instillation (control); PBS-sensitized and Staphylococcus aureus enterotoxin B (SEB) nasal instillation after nasal tamponade (SEB group); ovalbumin (OVA)-sensitized and nasal instillation (OVA group); and OVA-sensitized combined with OVA and SEB nasal instillation after nasal tamponade (OVA + SEB group). In the second experiment, we examined the role of IL-17A by dividing the mice into four groups: control group; ECRS group; ECRS + anti-IL-17A group; and ECRS + IL-17A group. The latter two groups received intraperitoneal injections of anti-IL-17A antibody or IL-17A, respectively.

RESULTS

We constructed a modified ECRS mouse model (OVA + SEB group), where the IL-17A levels were upregulated in the nasal sinus of ECRS mice and the IL-17A levels were significantly correlated with eosinophil infiltration. We further demonstrated that IL-17A induced type 2 inflammation and eosinophil infiltration in the ECRS group of mice. In contrast, IL-17A neutralization attenuated type 2 inflammatory cytokine secretion and eosinophil infiltration.

CONCLUSION

OVA sensitization and unilateral nasal tamponade, combined with SEB and OVA alternate nasal instillation (OVA + SEB group), could be used to construct a more typical ECRS mouse model in which IL-17A enhanced the expression of type 2 cytokines and eosinophil infiltration.

Novel strategies for inhibition of bacterial biofilm in chronic rhinosinusitis

An important role has been recently reported for bacterial biofilm in the pathophysiology of chronic diseases, such as chronic rhinosinusitis (CRS). CRS, affecting sinonasal mucosa, is a persistent inflammatory condition with a high prevalence around the world. Although the exact pathological mechanism of this disease has not been elicited yet, biofilm formation is known to lead to a more significant symptom burden and major objective clinical indicators. The high prevalence of multidrug-resistant bacteria has severely restricted the application of antibiotics in recent years. Furthermore, systemic antibiotic therapy, on top of its insufficient concentration to eradicate bacteria in the sinonasal biofilm, often causes toxicity, antibiotic resistance, and an effect on the natural microbiota, in patients. Thus, coming up with alternative therapeutic options instead of systemic antibiotic therapy is emphasized in the treatment of bacterial biofilm in CRS patients. The use of topical antibiotic therapy and antibiotic eluting sinus stents that induce higher antibiotic concentration, and decrease side effects could be helpful. Besides, recent research recognized that various natural products, nitric oxide, and bacteriophage therapy, in addition to the hindered biofilm formation, could degrade the established bacterial biofilm. However, despite these improvements, new antibacterial agents and CRS biofilm interactions are complicated and need extensive research. Finally, most studies were performed in vitro, and more preclinical animal models and human studies are required to confirm the collected data. The present review is specifically discussing potential therapeutic strategies for the treatment of bacterial biofilm in CRS patients.

ISMN-loaded PLGA-PEG nanoparticles conjugated with anti-Staphylococcus aureus α-toxin inhibit Staphylococcus aureus biofilms in chronic rhinosinusitis

Background: Staphylococcus aureus biofilms were linked to negative postsurgical outcomes of chronic rhinosinusitis (CRS). This study aims to develop a targeted nanoparticle and characterize its bactericidal effects. Methods: The authors prepared ISMN-loaded poly-lactide-co-glycolide acid (PLGA) and polyethylene glycol (PEG) nanoparticles conjugated with anti-S. aureus α-toxin (AA; ISMN-PLGA-PEG-AA), and determined its bactericidal and toxic effects. The antibiofilm propriety of ISMN-PLGA-PEG-AA was further investigated in a sheep CRS model. Results: ISMN-PLGA-PEG-AA had no toxic effect, while ISMN, ISMN-PLGA-PEG and ISMN-PLGA-PEG-AA had significantly anti-S. aureus effects. The blood concentrations and mRNA levels in sinus tissues of IL-4, IL-8 and IFN-γ in the sheep CRS model were significantly low. Conclusion: ISMN-PLGA-PEG-AA can effectively inhibit S. aureus biofilm, and is a promising drug for CRS treatment.

Characterizing the Microbiome of the Contracted Breast Capsule Using Next Generation Sequencing

BACKGROUND

Recent work suggests that bacterial biofilms play a role in capsular contracture (CC). However, traditional culture techniques provide only a limited understanding of the bacterial communities present within the contracted breast. Next generation sequencing (NGS) represents an evolution of polymerase chain reaction technology that can sequence all DNA present in a given sample.

OBJECTIVES

The aim of this study was to utilize NGS to characterize the bacterial microbiome of the capsule in patients with CC following cosmetic breast augmentation.

METHODS

We evaluated 32 consecutive patients with Baker grade III or IV CC following augmentation mammoplasty. Specimens were obtained from all contracted breasts (n = 53) during capsulectomy. Tissue specimens from contracted capsules as well as intraoperative swabs of the breast capsule and implant surfaces were obtained. Samples were sent to MicroGenDX Laboratories (Lubbock, TX) for NGS.

RESULTS

Specimens collected from 18 of 32 patients (56%) revealed the presence of microbial DNA. The total number of positive samples was 22 of 53 (42%). Sequencing identified a total of 120 unique bacterial species and 6 unique fungal species. Specimens with microbial DNA yielded a mean [standard deviation] of 8.27 [4.8] microbial species per patient. The most frequently isolated species were Escherichia coli (25% of all isolates), Diaphorobacter nitroreducens (12%), Cutibacterium acnes (12%), Staphylococcus epidermidis (11%), fungal species (7%), and Staphylococcus aureus (6%).

CONCLUSIONS

NGS enables characterization of the bacterial ecosystem surrounding breast implants in unprecedented detail. This is a critical step towards understanding the role this microbiome plays in the development of CC.

LEVEL OF EVIDENCE: 4

Effect of commercial nasal steroid preparation on bacterial growth

BACKGROUND

Topical budesonide (Pulmicort; AstraZeneca AB, Sodertalje, Sweden) is commonly used in the management of chronic rhinosinusitis (CRS). Although its use is due to its perceived anti-inflammatory effect, studies have suggested that it may also have antibacterial properties. To make the hydrophobic steroid molecule suitable for topical administration, pharmaceutical excipients are used in commercial steroid formulations. Herein we investigated the antibacterial action of commercial budesonide and its excipients.

METHODS

Planktonic and biofilm forms of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) were treated with Pulmicort or its excipients at clinically relevant concentrations. Bacterial growth was determined by optical density, resazurin assays, colony-forming unit counts, and Giemsa staining. Minimum inhibitory concentration (MIC) studies assessed excipients' potentiation of antibiotics. Experiments were conducted in triplicate and results analyzed using one-way analysis of variance.

RESULTS

There was significant reduction in planktonic and biofilm growth of S aureus and MRSA on exposure to budesonide (p < 0.0001) and its excipients (p < 0.0001). Excipient ethylene diamine-tetraactic acid (EDTA) demonstrated an antibacterial property even at the low concentrations used in topical preparations (p < 0.0001). With amoxicillin, excipients exhibited a potential additive/synergistic effect on MIC, whereas erythromycin and aminoglycosides showed an antagonistic action.

CONCLUSION

The commercial product Pulmicort has a direct antibacterial effect on the planktonic and biofilm forms of S aureus and MRSA. This effect is at least in part mediated through the excipient EDTA in the product. Excipients also influenced the antimicrobial activity of antibiotics depending on the bacterial strain and antibiotic tested.

The Condemned Sinus: Natural Disease or Surgical Sequela?

Background

Unilateral, mucopurulent drainage from an isolated paranasal sinus may be encountered in patients with a history of surgery for the treatment of chronic rhinosinusitis (CRS). Static mucus is visualized on nasal endoscopy within the sinus lumen but without significant disease in the adjacent sinuses. The reasons for this phenomenon are unknown although an iatrogenic cause is proposed.

Methods

A case series was prospectively compiled from consecutive patients presenting for evaluation of CRS at a tertiary rhinology practice during a 16-month period. Computerized tomography and nasal endoscopy were performed, and endoscopically directed aerobic and anaerobic bacterial cultures were obtained. Osteitis scores were recorded for diseased and nondiseased sides.

Results

Twenty-three of 113 patients (20.4%) had evidence of chronic unilateral drainage from either a maxillary (21) or sphenoid (2) sinus. Mean osteitis scores were higher for the diseased side (P < 0.01). A nonendoscopic transantral approach was reported in 57.1% of cases with chronic maxillary disease, with 52.2% occurring more than 10 years earlier. The most common bacterial isolate was Pseudomonas aeruginosa (6 cases, 26.1%), followed by methicillin-resistant Staphylococcus aureus (5 cases, 21.7%). Six cases (26.1%) were polymicrobial, and 6 (26.1%) were culture-negative. Tobacco use was reported in 8 (34.8%) cases, and chronic obstructive pulmonary disease was present in 6 (26.1%) cases.

Conclusion

The condemned sinus is a distinct entity that may represent a sequela of previous non-mucosal-sparing surgery. An association with hyperostosis is observed. Mucopurulent drainage is characterized by polymicrobial infection comparable to that found in diffuse CRS.

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.

Do Aging Factors Influence the Clinical Presentation and Management of Chronic Rhinosinusitis?

Objective/Hypothesis Chronic rhinosinusitis (CRS) is a complex inflammatory disease of the upper respiratory airways resulting from the dysregulation of immunity and epithelial defenses. More recently, the contribution of an altered nasal microbiome to the development of CRS has also been proposed. However, the impact of aging on the development of CRS has been long overlooked. Here we propose, in a hypothesis piece, that aging can influence the physiopathology of CRS and its subsequent management in an elderly population. Data Sources We summarize the recent literature findings supporting that elderly patients with CRS could be a distinct population from those with adult CRS and might require different or adjunct therapeutic approaches. Methods Review of recent literature of the effect of aging and its possible effects in CRS using 3 different databases. Conclusions Age-dependent decrease in the levels of the S100 family proteins involved in epithelial proliferation, repair, and defenses combined with chronic inflammation might lead to an increased risk of abnormal microbial colonization and loss of microbiota diversity. Ultimately, these changes could have the potential to alter the physiopathology of CRS in the elderly. Implications Unlike in adults, in whom CRS T_h2-skewed responses with eosinophilia are thought to play a critical role, in aging populations, a microbiome and epithelial barrier dysfunctions may instead be the pivotal agents of disease development and persistence. This supports that therapies for elderly patients may require a different management or additional targeted therapies to control the disease. Prospective studies, however, are necessary to validate this concept.

Tolerance and pharmacokinetics of a ciprofloxacin-coated sinus stent in a preclinical model

BACKGROUND

Chronic rhinosinusitis (CRS) is often associated with persistent bacterial infection despite the use of systemic antibiotics. Topically administered antibiotics are an alternative strategy, but require effective local concentrations, prolonged mucosal contact time, minor systemic absorption, and minimal depletion. The objectives of the current study were to analyze the in vitro release rate and in vivo drug delivery tolerance and pharmacokinetics of a ciprofloxacin-coated sinus stent (CSS).

METHODS

The CSS (2 mg) was created from biodegradable poly-D/L-lactic acid. After analyzing in vitro release profile, CSSs were placed unilaterally in maxillary sinuses of 16 rabbits via dorsal sinusotomy. Animals were euthanized between 1 and 3 weeks postoperatively. Ciprofloxacin concentrations in the sinus tissue and plasmas were assessed using high-performance liquid chromatography. Radiological and histological evaluations were performed.

RESULTS

In the in vitro release profile, an initial burst release was observed over the first 24 hours, followed by sustained release through the 14-day time point. In the rabbit model, ciprofloxacin was continuously released from the stent up to 3 weeks at doses >50 ng/mL. Histologic examination found no evidence of inflammation, epithelial ulceration, or bony reaction upon euthanization of the animals at 21 days. Computed tomography also demonstrated no signs of mucosal edema or opacification in the sinus.

CONCLUSION

The CSS was safe in this preclinical model and sustained release was observed in both the in vitro and in vivo analyses. The innovative stent design coated with ciprofloxacin may provide a unique therapeutic strategy for chronic rhinosinusitis (CRS).

Intranasal delivery of ciprofloxacin to rats: A topical approach using a thermoreversible in situ gel

Intranasal administration of antibiotics is an alternative and attractive delivery approach in the treatment of local infections such as chronic rhinosinusitis. This topical route has the advantage of delivering high drug concentrations directly to the site of infection when trying to eradicate the highly resistant bacterial biofilms. The purpose of this study was to assess and compare the pharmacokinetic parameters of ciprofloxacin following intranasal and intravenous administrations to rats in plasma, olfactory bulb and nasal mucosa of two different nasal regions. For intranasal administration a thermoreversible in situ gel was used to increase drug residence time in nasal cavity. Ciprofloxacin concentration time-profile in nasal mucosa of the studied anterior region (at naso- and maxilloturbinates level) was markedly higher after intranasal administration (0.24mg/kg) than that following intravenous administration (10mg/kg), while in nasal mucosa of the more posterior region (at ethmoidal turbinates level) ciprofloxacin concentrations were found to be higher after intranasal administration when the different dose administered by both routes is taken into account. A plateau in ciprofloxacin concentration was observed in nasal mucosa of both studied regions after intranasal administration, suggesting a slow delivery of the drug over a period of time using the nasal gel formulation. In plasma and olfactory bulb, concentration of ciprofloxacin was residual after intranasal administration, which demonstrates this is a safe administration route by preventing systemic and particularly central nervous system adverse effects. Dose-normalized pharmacokinetic parameters of ciprofloxacin exposure to nasal mucosa revealed higher values after intranasal delivery not only in the anterior region but also in the posterior nasal region. In conclusion, topical intranasal administration appears to be advantageous for delivering ciprofloxacin to the biophase, with negligible systemic and brain exposure using a 41.7-fold lower dose than intravenous administration. Therefore, it may represent a promising approach in the drug management of chronic rhinosinusitis.

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.

Clinical predictors of neo-osteogenesis in patients with chronic rhinosinusitis

BACKGROUND

Neo-osteogenesis of the paranasal sinuses is a radiologic finding of unclear clinical significance. Although current evidence suggests that these bony changes represent an inflammatory response rather than an infectious osteitis, bacteria associated with the sinonasal mucosa may induce inflammatory mediators as a mechanism of neo-osteogenesis. The objectives of this study were (1) to determine whether there is an association between bacteria isolated on sinus culture and neo-osteogenesis, and (2) to identify other predictive factors for neo-osteogenesis.

METHODS

Ninety patients undergoing sinus surgery for medically refractory CRS were recruited. Radiologic evidence of neo-osteogenesis was assessed by the Global Osteitis Scoring Scale (GOSS) and mucosal disease severity was assessed by the Lund-Mackay score (LMS). Bacterial culture was obtained endoscopically at the preoperative office visit or during surgery. Multiple and logistic regression models were used to evaluate the association between the types of bacterial species isolated, number of previous surgeries, and severity of neo-osteogenesis.

RESULTS

Thirty of the 90 (33.3%) patients had radiologic evidence of neo-osteogenesis. Pseudomonas aeruginosa was significantly associated with neo-osteogenesis (odds ratio [OR], 3.97; 95% confidence interval [CI], 1.12 to 13.56), whereas Staphylococcus aureus was not. The number of previous surgeries, especially 2 or more previous surgeries, was associated with the extent of neo-osteogenesis (OR, 3.48; 95% CI, 1.14 to 10.51). The LMS was also significantly associated with the extent of neo-osteogenesis.

CONCLUSION

The presence of P. aeruginosa in the sinuses is an independent predictor of neo-osteogenesis, whereas S. aureus is not. The number of previous surgeries and the LMS are also independently associated with the severity of neo-osteogenesis.

Effect of topical ofloxacin on bacterial biofilms in refractory post-sinus surgery rhino-sinusitis

Bacterial biofilms have been shown to play a major role in many chronic infections, in addition, there is growing evidence that bacterial biofilms may play a role in some forms of refractory CRS that persists despite proper surgery and culture directed antibiotic therapy. The objective is to determine the effect of application of topical ofloxacin on nasal and sinus mucosa in patients with proven existence of bacterial biofilms and persistent chronic sinusitis after FESS. The study design is a prospective controlled study. The study included a total of 12 patients who had refractory CRS in spite of undergoing FESS for that specific reason (study group), and control group (involved 25 patients), for whom FESS was done, with complete improvement postoperatively in 15 of them, and persistence of symptoms in the other ten. Topical ofloxacin eye drops (0.3 %) tds for 12 weeks were prescribed for (study group), culture and sensitivity and scanning electron microscopy were done for middle meatal mucosal specimens for all patients and controls, all of them were followed up for a minimum of 9 months (range 9-18 months). Of the study group, 80 % showed marked improvement in the structure of the mucosa, with the regaining of normal respiratory epithelium, with complete disappearance of the biofilm surface, and the remaining 20 % showed only reduction in the number of inflammatory cells and regaining cilia with scattered patches of very thin biofilm. Biofilms formation plays an active role in perpetuating inflammation in CRS patients and enhanced the recurrence and resistance in those patients, we found a statistically significant improvement in patients' group (P < 0.001), after 12 weeks of topical ofloxacin (without any evidence of any side effects). So, we concluded that topical ofloxacin seems to be an effective, tolerable, convenient, cheap and even safe mode of treatment of refractory CRS after FESS due to biofilms' formation. Thus, we recommend such modality of treatment postoperatively especially in refractory cases of CRS.

Cousins, siblings, or copies: the genomics of recurrent Staphylococcus aureus infections in chronic rhinosinusitis

BACKGROUND

Staphylococcus aureus infection is known to play a role in recalcitrant chronic rhinosinusitis (CRS). However, it is unknown if recurrent S. aureus infections are caused by the same strain or are due to independent acquisitions of different strains.

METHODS

Samples were collected from patients with CRS from July 2011 to August 2012. S. aureus was isolated from mucosal swabs and tissue specimens from patients who underwent surgery during the study period, or from swabs of areas of purulence taken in the postoperative period under endoscopic guidance. Pulsed-field gel electrophoresis was used to characterize S. aureus isolates.

RESULTS

Thirty-four patients were included in the study; 79% showed persistence of the same S. aureus strain in their paranasal sinuses (p = 0.001; H1 ≠ 50%). Furthermore, a significantly high frequency of patients with known biofilm status were positive for S. aureus biofilm (p = 0.002; H1 ≠ 50%). When patients were stratified according to disease evolution postsurgery, certain strains appeared to be more commonly associated with symptom persistence.

CONCLUSION

The same S. aureus strain appears to persist in the paranasal sinuses of CRS patients despite multiple courses of culture-directed antibiotics. This suggests that conventional antimicrobial therapies in patients with CRS may not eliminate the organism. This may be partly explained by the formation of biofilms in the paranasal sinus region.

Liposome-encapsulated ISMN: a novel nitric oxide-based therapeutic agent against Staphylococcus aureus biofilms

Background

Staphylococcus aureus in its biofilm form has been associated with recalcitrant chronic rhinosinusitis with significant resistance to conventional therapies. This study aims to determine if liposomal-encapsulation of a precursor of the naturally occurring antimicrobial nitric oxide (NO) enhances its desired anti-biofilm effects against S. aureus, in the hope that improving its efficacy can provide an effective topical agent for future clinical use.

Methodology

S. aureus ATCC 25923 biofilms were grown in-vitro using the Minimum Biofilm Eradication Concentration (MBEC) device and exposed to 3 and 60 mg/mL of the NO donor isosorbide mononitrate (ISMN) encapsulated into different anionic liposomal formulations based on particle size (unilamellar ULV, multilamellar MLV) and lipid content (5 and 25 mM) at 24 h and 5 min exposure times. Biofilms were viewed using Live-Dead Baclight stain and confocal scanning laser microscopy and quantified using the software COMSTAT2.

Results

At 3 and 60 mg/mL, ISMN-ULV liposomes had comparable and significant anti-biofilm effects compared to untreated control at 24 h exposure (p = 0.012 and 0.02 respectively). ULV blanks also had significant anti-biofilm effects at both 24 h and 5 min exposure (p = 0.02 and 0.047 respectively). At 5 min exposure, 60 mg/mL ISMN-MLV liposomes appeared to have greater anti-biofilm effects compared to pure ISMN or ULV particles. Increasing liposomal lipid content improved the anti-biofilm efficacy of both MLV and ULVs at 5 min exposure.

Conclusion

Liposome-encapsulated “nitric oxide” is highly effective in eradicating S. aureus biofilms in-vitro, giving great promise for use in the clinical setting to treat this burdensome infection. Further studies however are needed to assess its safety and efficacy in-vivo before clinical translation is attempted.

A pilot study into the effect of low-level laser therapy in patients with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a common inflammatory disease of the nose and paranasal sinuses that has a significant impact on patients' quality of life. No study has examined the effectiveness of applying low-level laser therapy (LLLT) locally over the sinuses in patients with CRS. The aim of this study was to evaluate the effect of LLLT in patients with CRS. Fifteen adult patients with CRS participated in this pilot pretest-posttest clinical study. Patients were treated with a 830-nm Ga-Al-As laser in continuous-wave mode at a power output of 30 mW and energy dose of 1 J. Laser irradiation was delivered on six points over each maxillary or frontal sinus with 33 sec irradiation for each point and a total treatment duration of 198 sec for each sinus. Patients were given LLLT three times per week for ten treatment sessions. Patients were asked to score their symptoms in accordance with a four-point scale (0-3), and a total symptom score (TSS) for each patient was calculated. Percentage improvement of TSS was considered as the primary outcome measure. TSS was calculated at baseline (T0), at 2 weeks (T1) and at 4 weeks (T2). The TSS was improved significantly at T1 (39%) and at T2 (46.34%). A large effect size for LLLT was found (ηp(2) ηp(2)  =  0.63). The therapeutic effect was sustained for a mean of 5 months. This pilot study indicates that LLLT applied for 4 weeks improves symptoms in patients with CRS.

Endotypes and phenotypes of chronic rhinosinusitis: a PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology

Chronic rhinosinusitis (CRS) is a complex disease consisting of several disease variants with different underlying pathophysiologies. Limited knowledge of the mechanisms of these disease subgroups is possibly the greatest obstacle in understanding the causes of CRS and improving treatment. It is generally agreed that there are clinically relevant CRS phenotypes defined by an observable characteristic or trait, such as the presence or absence of nasal polyps. Defining the phenotype of the patient is useful in making therapeutic decisions. However, clinical phenotypes do not provide full insight into all underlying cellular and molecular pathophysiologic mechanisms of CRS. Recognition of the heterogeneity of CRS has promoted the concept that CRS consists of multiple groups of biological subtypes, or "endotypes," which are defined by distinct pathophysiologic mechanisms that might be identified by corresponding biomarkers. Different CRS endotypes can be characterized by differences in responsiveness to different treatments, including topical intranasal corticosteroids and biological agents, such as anti-IL-5 and anti-IgE mAb, and can be based on different biomarkers that are linked to underlying mechanisms. CRS has been regarded as a single disease entity in clinical and genetic studies in the past, which can explain the failure to identify consistent genetic and environmental correlations. In addition, better identification of endotypes might permit individualization of therapy that can be targeted against the pathophysiologic processes of a patient's endotype, with potential for more effective treatment and better patient outcomes.

The effect of antimicrobial photodynamic therapy on human ciliated respiratory mucosa

BACKGROUND

Chronic recurrent sinusitis (CRS) is one of the most common chronic conditions in the United States. There is a significant subpopulation of CRS patients who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. Antimicrobial photodynamic therapy (aPDT) is a noninvasive nonantibiotic broad spectrum antimicrobial treatment. Our previous in vitro studies demonstrated that aPDT reduced CRS polymicrobial biofilm and planktonic bacteria and fungi by > 99.9% after a single treatment. Prior to human treatment however, aPDT treatment must be demonstrated to not result in histologic damage to the sinus ciliated respiratory epithelium. The objective of this study was to demonstrate the safety of aPDT treatment on a living human ciliated respiratory mucosal model (EpiAirway).

METHODS

A study of aPDT treatment of EpiAirway was performed. Treatment groups included a nontreatment control, laser light alone, photosensitizer alone, and therapeutic photosensitizer and light combination (aPDT). At completion of treatment, the EpiAirway tissue was fixed in 10% formalin, paraffin-embedded, sectioned, H&E stained and mounted. All samples were blinded and microscopically examined by a human pathologist to assess any effect of aPDT on the tissue, cilia, or mucosal glands. The results were correlated with the treatment parameters.

RESULTS

The EpiAirway histologic study demonstrated no histologic alteration of the respiratory cilia or mucosal epithelium in any of the treatment groups.

CONCLUSIONS

aPDT is a safe treatment for CRS resulting in no histologic alteration of human ciliated respiratory mucosa as is found in the human sinuses.

Mometasone implant for chronic rhinosinusitis

The Propel mometasone-eluting stent (Intersect ENT, Palo Alto, CA) is the first Food and Drug Administration-approved device for delivering steroid medication into the ethmoid cavity following surgery. The implant is composed of a biodegradable polymer in a lattice pattern that expands in a spring-like fashion to conform to the walls of a dissected ethmoid cavity and contains a total of 370 μg of mometasone furoate designed for gradual release over 30 days. The purpose of this article is to review the mode of action and the evidence supporting the efficacy of this novel technology. Three recently published clinical trials have demonstrated that the mometasone-eluting stent produced statistically significant reductions in inflammation, polyp formation, and postoperative adhesions. In addition, the implant has been found to significantly reduce the need for postoperative administration of oral steroids and to decrease the frequency of postoperative lysis of adhesions. Minimal adverse effects were reported in these trials and included infection, crusting, and granulation tissue formation. Although the placement of steroid-impregnated packing, stents, sponges, and gels has previously been used in the postoperative sinus cavities, the Propel mometasone-eluting stent introduces a new mechanism for localized and controlled delivery of topical therapy directly to the nasal mucosa for chronic rhinosinusitis.

Efficacy of NVC-422 against Staphylococcus aureus biofilms in a sheep biofilm model of sinusitis

BACKGROUND

Bacterial biofilms are a major obstacle in management of recalcitrant chronic rhinosinusitis. NVC-422 is a potent, fast-acting, broad-spectrum, nonantibiotic, antimicrobial with a new mechanism of action effective against biofilm bacteria in in vitro conditions. The aim of this study was to investigate the safety and efficacy of NVC-422 as local antibiofilm treatment in a sheep model of rhinosinusitis.

METHODS

After accessing and occluding frontal sinus ostia in 24 merino sheep via staged endoscopic procedures, S. aureus clinical isolate was instilled in frontal sinuses. Following biofilm formation, ostial obstruction was removed and sinuses irrigated with 0.1% and 0.5% NVC-422 in 5 mM acetate isotonic saline at pH 4.0. Sheep were monitored for adverse effects and euthanized 24 hours after treatment. Frontal sinuses were assessed for infection and changes in mucosa after the treatment. S. aureus biofilms were identified with Baclight-confocal scanning microscopy protocol and the biofilm biomass assayed by applying the COMSTAT2 program to recorded image stacks.

RESULTS

After 2 irrigations with 0.1% NVC-422, S. aureus biofilm biomass was reduced when compared to control sinuses (p = 0.0001), though this effect was variable in samples. NVC-422 0.5% solution irrigations reduced biofilm even more significantly and consistently over all samples (p < 0.0001). NVC-422 0.5% was also more effective than 0.1% NVC-422, vehicle control, and normal saline sinus irrigations in reducing biofilm biomass (p < 0.05 for all subgroups). No adverse events were observed in sheep after sinus irrigations with 0.1% and 0.5% NVC-422 solutions.

CONCLUSION

NVC-422 is an effective topical agent against S. aureus biofilms, with dose-dependent efficacy in this animal model of biofilm-associated sinusitis.

Prevalence of Biofilms and Their Response to Medical Treatment in Chronic Rhinosinusitis without Polyps

Objective. The aim of this study was to investigate the prevalence of biofilms and the effects of medical treatment modalities in chronic rhinosinusitis (CRS) patients without nasal polyps.

Study Design. Randomized controlled trial.

Settings. Tertiary referral hospital.

Subjects and Methods. The authors randomly divided 32 adult patients with CRS without nasal polyps into 2 groups. In the first group (n = 16), oral clarithromycin was administered 500 mg/bid for 2 weeks and then 250 mg/d for the following 6 weeks. In the second group (n = 16), an 8-week course of 200-mcg/d topical mometasone furoate was added to the clarithromycin regimen, identical to the first group. The pre- and posttreatment nasal tissue samples were evaluated by scanning electron microscopy for biofilm prevalence and graded from 0 to 3 according to density and extension.

Results. Biofilms were detected in 24 of 32 patients (75%) before the treatment (grades 1-3). Biofilms were detected in 14 of 32 patients (43.8%) after the treatment (grades 1-2). When each group was evaluated independently, there was a significant improvement after the treatment in both groups I and II. When the biofilm grades of group I were compared to those of group II, there was no significant difference both in the pre- and posttreatment evaluation.

Conclusion. The prevalence of biofilms in CRS without polyps was 75% in our study. Regression of biofilms to 43% was observed under medical treatment. Adding nasal steroids to macrolides gave no further benefit.

Nasal polyposis: current trends

Nasal polyps (NP) are one of the most common inflammatory mass lesions of the nose, affecting up to 4% of the population. They present with nasal obstruction, anosmia, rhinorrhoea, post nasal drip, and less commonly facial pain. Their etiology remains unclear, but they are known to have associations with allergy, asthma, infection, fungus, cystic fibrosis, and aspirin sensitivity. However, the underlying mechanisms interlinking these pathologic conditions to NP formation remain unclear. Also strong genetic factors are implicated in the pathogenesis of NP, but genetic and molecular alterations required for its development and progression are still unclear. Management of NP involves a combination of medical therapy and surgery. There is good evidence for the use of corticosteroids (systemic and topical) both as primary treatment and as postoperative prophylaxis against recurrence, but the prolonged course of the disease and adverse effects of systemic steroids limits their use. Hence several new drugs are under trial. Surgical treatment has been refined significantly over the past 20 years with the advent of endoscopic sinus surgery and, in general, is reserved for cases refractory to medical treatment. Recurrence of the polyposis is common with severe disease recurring in up to 10% of patients. Over the last two decades, increasing insights in the pathophysiology of nasal polyposis opens perspective for new pharmacological treatment options, with eosinophilic inflammation, IgE, fungi and Staphylococcus aureus as potential targets. A better understanding of the pathophysiology underlying the persistent inflammatory state in NP is necessary to ultimately develop novel pharmacotherapeutic approaches. In this paper we present the newer treatment options available for better control and possibly cure of the disease.

Polymorphisms in the nitric oxide synthase 1 gene are associated with severe chronic rhinosinusitis

BACKGROUND

Nitric oxide (NO), is a biological messenger molecule and a component of innate immunity, with important roles in the regulation of inflammation and in defense against bacterial biofilms. Polymorphisms in genes regulating NO production have the potential for a role in the development of chronic rhinosinusitis (CRS). The purpose of this study was to determine whether polymorphisms in genes regulating NO synthesis are associated with CRS.

METHODS

An established population of 206 individuals with severe CRS and 196 postal code-matched controls was previously screened using a pooling genome-wide associations study to estimate allelic frequency. Genes regulating NO synthesis with a maximal probability of association were identified. High-probability single nucleotide polymorphisms SNPs from the NO synthase (NOS1) and its ligand NOS1 adaptor protein (NOS1AP) genes were retained for individual genotyping. PLINK software was used to determine association.

RESULTS

Sixteen SNPs were genotyped successfully with a genotype distribution in agreement with Hardy-Weinberg equilibrium. Two SNPs for NOS1 (rs1483757 and rs9658281) were significantly associated with CRS, with a protective effect. The severe subphenotype showed stronger associations. Subgroup analysis for the presence of nasal polyps, origin, and gender did not influence strength of associations.

CONCLUSION

These data suggest that polymorphisms in the NOS1 gene may play a role in the susceptibility to develop CRS. Study findings apply to patients with severe CRS, unresponsive to surgery.

Adenoids during Childhood: The Facts

Adenoids are constantly exposed to viral and bacterial agents as well as to allergens. They play a major role in the upper airways immunity, being effector organs in both mucosal-type and systemic-type adaptive immunity. Because of both their immunological function and their specific location, adenoids are considered to be as reservoirs of viruses and bacteria. Reiterative infections may therefore contribute both to Eustachian tube dysfunction and to tissue hypertrophy. Nasal endoscopy is a key diagnostic tool to detect both adenoid hypertrophy and adenoiditis. Moreover, such a procedure may be very helpful in detecting bacterial biofilms that could justify the concomitant presence of recurrent episodes of otitis media, chronic and occult sinusitis in children. Even though the connection between allergies and adenoidal diseases is not completely clear, allergic diseases cause an inflammatory state that influences adenoidal tissue as well, configuring the picture of allergic adenoiditis, a condition in which adenoid tissue exhibit numerous IgE positive mast cells. Several studies are still needed to better understand the relationship between allergies and infections and the influence they play on adenoids during childhood.

Antimicrobial photodynamic therapy treatment of chronic recurrent sinusitis biofilms

BACKGROUND

Chronic recurrent sinusitis (CRS) is an inflammatory disease of the facial sinuses and nasal passages that is defined as lasting longer than 12 weeks or occurring more than 4 times per year with symptoms usually lasting more than 20 days. The National Institute for Health Statistics estimates that CRS is one of the most common chronic conditions in the United States, affecting an estimated 37 million Americans. The potential etiologies of CRS include bacteria, viruses, allergies, fungi, superantigens, and microbial biofilms. In clinical practice there is a significant subpopulation of patients with CRS who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. The reason for treatment failure is thought to be related to the destruction of the sinus mucociliary defense by the chronic sinus infection resulting in the development of secondary antibiotic-resistant microbial colonization of the sinuses and biofilm formation. Antimicrobial photodynamic therapy (aPDT) is a nonantibiotic broad-spectrum antimicrobial treatment that has been demonstrated to eradicate antibiotic-resistant bacteria and biofilms. The objective of this study was to demonstrate the effectiveness of a noninvasive aPDT treatment method of eradicating antibiotic resistant biofilms/microorganisms known to cause CRS in an in vitro model.

METHODS

Antibiotic-resistant planktonic bacteria and fungi and polymicrobial biofilms of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were grown on silastic sheets and treated with a methylene blue photosensitizer and 670 nm non-thermal-activating light. Cultures of the planktonic microorganisms and biofilms were obtained before and after light treatment to determine efficacy of planktonic bacteria and biofilm reduction.

RESULTS

The in vitro CRS planktonic microorganism and biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.9% after a single treatment.

CONCLUSION

aPDT can effectively treat CRS polymicrobial antibiotic-resistant bacteria, fungi, and biofilms in vivo. Human clinical studies are currently planned to assess the safety and efficacy of this treatment for CRS.

Diagnostic accuracy of nasopharyngeal swabs in detecting biofilm-producing bacteria in chronic adenoiditis: a preliminary study

OBJECTIVES

Biofilms are organized bacterial communities that are playing an increasing role in otolaryngological diseases such as chronic or recurrent middle ear otitis and adenotonsillitis. Various cultural techniques are available to detect biofilm-producing bacteria (BPB), but microbiological analysis of bioptic staining is the reference diagnostic procedure. To our knowledge, the accuracy of nasopharyngeal swabs in diagnosing BPB has never been assessed.

STUDY DESIGN

A prospective study of diagnostic accuracy.

SETTING

Outpatient clinics of the Departments of Specialist Surgical Sciences and Maternal and Pediatric Sciences, University of Milan, Italy.

SUBJECTS AND METHODS

Forty-two pediatric subjects with chronic adenoiditis (aged 4-18 years) underwent adenoidectomy, during which multiple transoral nasopharyngeal swabs and adenoidal biopsies were performed. BPB were detected by spectrophotometry, and the accuracy of detecting BPB in nasopharyngeal swabs was compared with that of biopsy.

RESULTS

BPB were detected in 73.8% of the nasopharyngeal swabs and in 69.1% of the biopsies. The sensitivity and specificity of the nasopharyngeal swabs were, respectively, 75.9% (95% confidence interval [CI], 60.3%-91.4%) and 30.8% (95% CI, 5.7%-55.9%); positive and negative predictive values were, respectively, 71.0% (95% CI, 55.0%-86.9%) and 36.4% (95% CI, 7.9%-64.8%); and the area under the receiver-operating characteristic curve was 0.5 (95% CI, 0.4-0.7).

CONCLUSIONS

In comparison with biopsy, nasopharyngeal swabs seem to be inaccurate in detecting BPB and should be cautiously used in clinical practice. As these preliminary findings may have been due to the well-known resistance of biofilm to mechanical injuries (such as swab rubbing) or the small study population, they need to be confirmed in larger patient series.

Actual concepts in rhinosinusitis: a review of clinical presentations, inflammatory pathways, cytokine profiles, remodeling, and management

Rhinosinusitis (RS) is a heterogeneous group of diseases. It is a significant and increasing health problem that affects about 15% of the population in Western countries. It has a substantial impact on patients’ health-related quality of life and daily functioning and represents a huge financial burden to society and the health care system as a result of the direct and indirect costs. In addition, RS is not well-understood, and little is known about the etiology and pathophysiology. In the past decade, many papers have been published that have changed our understanding of RS. RS is commonly classified into acute and chronic RS based on symptom duration. In acute RS, an inflammatory reaction initiated by a viral infection characterizes most uncomplicated, mild to moderate cases. Therefore, the first line of treatment for these cases are intranasal steroids and not antibiotics. In severe and complicated cases, antibiotics combined with topical steroids remain the treatment of choice. On the other hand, chronic RS is actually subdivided into two distinct entities (chronic rhinosinusitis with and without polyps), as growing evidence indicates that these entities have specific inflammatory pathways and cytokine profiles. The authors review recent data regarding the clinical presentations, cytokine profiles, tissue remodeling, and modalities of treatment for each form of RS.

Laser disruption and killing of methicillin-resistant Staphylococcus aureus biofilms

OBJECTIVE

The aim of the study was to study the efficacy of 2 different lasers in vitro, in disrupting biofilm and killing planktonic pathogenic bacteria.

MATERIALS AND METHODS

Biofilms of a stable bioluminescent of Staphylococcus aureus Xen 31 were grown in a 96-well microtiter plate for 3 days. The study included 7 arms: (a) control; (b) ciprofloxacin (3 mg/L, the established minimum inhibitory concentration [MIC]) alone; (c) shock wave (SW) laser alone; (d) near-infrared (NIR) laser alone; (e) SW laser and ciprofloxacin; (f) SW and NIR lasers; (g) SW, NIR lasers, and ciprofloxacin. The results were evaluated with an in vivo imaging system (IVIS) biophotonic system (for live bacteria) and optical density (OD) for total bacteria.

RESULTS

Without antibiotics, there was a 43% reduction in OD (P < .05) caused by the combination of SW and NIR suggesting that biofilm had been disrupted. There was an 88% reduction (P < .05) in live biofilm. Ciprofloxacin alone resulted in a decrease of 28% of total live cells (biofilm remaining attached) and 58% of biofilm cells (both P > .05). Ciprofloxacin in combination with SW and SW + NIR lasers caused a decrease of more than 60% in total live biomass and more than 80% of biofilm cells, which was significantly greater than ciprofloxacin alone (P < .05).

CONCLUSIONS

We have demonstrated an effective nonpharmacologic treatment method for methicillin-resistant Staphylococcus aureus (MRSA) biofilm disruption and killing using 2 different lasers. The preferred treatment sequence is a SW laser disruption of biofilm followed by NIR laser illumination. Treatment optimization of biofilm is possible with the addition of ciprofloxacin in concentrations consistent with planktonic MIC.

Therapeutic ultrasound as treatment for chronic rhinosinusitis: preliminary observations

BACKGROUND

Bacterial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis. In the laboratory setting, ultrasound is effective in disrupting such biofilms; however, few clinical studies have evaluated the role of therapeutic ultrasound in chronic rhinosinusitis.

OBJECTIVE

This study was performed to investigate the short-term effectiveness of therapeutic ultrasound as a treatment modality for chronic rhinosinusitis.

METHODS

Twenty-two patients with a positive history of chronic rhinosinusitis, according to the criteria set out by the Rhinosinusitis Task Force, together with a previous computed tomography scan compatible with a diagnosis of chronic rhinosinusitis, and who had failed previous, aggressive medical management, were treated with therapeutic pulsed ultrasound at 1 MHz two to three days per week for six sessions. Patients completed an assessment of individual sinus symptom severity and the 20-Item Sino-Nasal Outcome Test questionnaire before treatment, prior to session four and after completion of session six.

RESULTS

Two patients were unable to complete the study protocol. After completion of session six, 18 patients had experienced improvement in symptoms, while two patients noted a worsening of symptoms. Median percentage improvement of the total overall symptom score was 16.7 per cent (Wilcoxon signed rank, p < 0.001). The 20-Item Sino-Nasal Outcome Test score improved by 34.1 per cent (Wilcoxon signed rank, p < 0.0001).

CONCLUSION

This study demonstrated a significant improvement in chronic rhinosinusitis symptoms after a six-session course of pulsed ultrasound therapy. Treatment with ultrasound alone or combined with antibiotics may provide a strategy to target biofilms on the sinus mucosa. Therapeutic ultrasound warrants further investigation as a potential treatment modality for chronic rhinosinusitis.

Bacterial flora in normal adult maxillary sinuses

BACKGROUND

Conflicting data exist about the presence of bacteria in healthy maxillary sinus cavities. This study was designed to determine the bacterial flora and to quantify the level of bacterial presence in healthy maxillary sinus cavities.

METHOD

Subjects included 34 patients undergoing Lefort I osteotomy for orthognathic surgery. All patients were preoperatively evaluated by a questionnaire and a complete physical examination including sinus endoscopy. Our exclusion criteria were presence of sinonasal symptoms, asthma, antibiotic treatment in the past 3 months, treatment with local steroids, previous sinonasal surgery, traumatic surgery, and an abnormal CT scan or sinus endoscopy. Washes were obtained from maxillary sinuses before surgery through an antral puncture. The sinus was irrigated with sterile saline followed by aspiration with a syringe attached to the trocar. Basic sterility rules were rigorously applied. Specimens were transported to the laboratory in an air-free syringe. Time between collection of materials and inoculation of the specimen did not exceed 15 minutes. Specimens were inoculated for aerobic and anaerobic organisms.

RESULTS

After applying the selection criteria, 14 patients (28 sinuses) remained. Eight (57.1%) were men with a mean age of 22.7 years; 82.14% of the specimens were sterile. Bacterial organisms were recovered in only four patients with two different coagulase-negative staphylococci in the same patient: one in each sinus with 200 UFC/mL in the left sinus and 10 UFC/mL in the right sinus, one Citrobacter fundii (70 UFC/mL) and two polymorphic floras.

CONCLUSION

This descriptive study shows the large predominance of sterile maxillary sinus cavities in asymptomatic adults with endoscopically normal mucosa.