Understanding the Role of Biofilms and Superantigens in Chronic Rhinosinusitis

Biofilm-producing Bacteria and Quality of Life after Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis with Nasal Polyposis

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common health disorders in humans and has a major impact on health-related quality of life (HRQoL). Of the many factors contributing to the etiology of CRS, less is known about the correlation between CRS and bacterial biofilms and their impact on HRQoL.

OBJECTIVE

The aim of this prospective study was to investigate the relationship between biofilm-producing bacteria and patients' objective findings and HRQoL.

METHODS

Forty-eight patients with CRSwNP were enrolled in a 12-month prospective study. The Lund-Mackay (LM) CT and endoscopic Lund-Kennedy (LK) scores were obtained before endoscopic sinus surgery (ESS), and patients completed the HRQoL instruments: the 22-item Sinonasal Outcome Test (SNOT-22), the 36-item Short Questionnaire (SF-36), and the visual analog scale (VAS). A sinus culture was obtained at ESS, bacteria were isolated, and in vitro quantification of the biofilm was performed. The LK score and HRQoL were determined postoperatively at months 1, 3, 6, and 12.

RESULTS

The most common bacterial isolates in patients with CRSwNP were Staphylococcus aureus (28%), coagulase-negative staphylococci (52%), and Pseudomonas aeruginosa (8%). Preoperatively, the highest LM and LK scores were found in patients with strong biofilm producers. Postoperative LK scores were significantly reduced in all patients. Postoperative VAS scores were significantly reduced from month 1 to month 12 postoperatively. Patients with strong biofilm producers had significantly worse nasal blockage, secretion, headache, facial pressure and pain, and loss of smell preoperatively, compared to patients with low biofilm producers. The most significant reduction in preoperative scores SNOT-22 and SF-36 (excluding physical functioning) was seen in patients with S. aureus and P. aeruginosa.

CONCLUSIONS

Patients with strong biofilm producers had higher LK and LM scores preoperatively, and greater improvement in LK and HRQoL scores postoperatively. Microbiologic surveillance of all CRS patients is recommended.

Z-Form Extracellular DNA in Pediatric CRS May Provide a Mechanism for Recalcitrance to Treatment

OBJECTIVES

We examined sinus mucosal samples recovered from pediatric chronic rhinosinusitis (CRS) patients for the presence of Z-form extracellular DNA (eDNA) due to its recently elucidated role in pathogenesis of disease. Further, we immunolabeled these specimens for the presence of both members of the bacterial DNA-binding DNABII protein family, integration host factor (IHF) and histone-like protein (HU), due to their known role in converting common B-DNA to the rare Z-form.

METHODS

Sinus mucosa samples recovered from 20 patients during functional endoscopic sinus surgery (FESS) were immunolabelled for B- and Z-DNA, as well as for both bacterial DNABII proteins.

RESULTS

Nineteen of 20 samples (95%) included areas rich in eDNA, with the majority in the Z-form. Areas positive for B-DNA were restricted to the most distal regions of the mucosal specimen. Labeling for both DNABII proteins was observed on B- and Z-DNA, which aligned with the role of these proteins in the B-to-Z DNA conversion.

CONCLUSIONS

Abundant Z-form eDNA in culture-positive pediatric CRS samples suggested that bacterial DNABII proteins were responsible for the conversion of eukaryotic B-DNA that had been released into the luminal space by PMNs during NETosis, to the Z-form. The presence of both DNABII proteins on B-DNA and Z-DNA supported the known role of these bacterial proteins in the B-to-Z DNA conversion. Given that Z-form DNA both stabilizes the bacterial biofilm and inactivates PMN NET-mediated killing of trapped bacteria, we hypothesize that this conversion may be contributing to the chronicity and recalcitrance of CRS to treatment.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1564-1571, 2024.

Expert consensus on odontogenic maxillary sinusitis multi-disciplinary treatment

ABSTARCT

Odontogenic maxillary sinusitis (OMS) is a subtype of maxillary sinusitis (MS). It is actually inflammation of the maxillary sinus that secondary to adjacent infectious maxillary dental lesion. Due to the lack of unique clinical features, OMS is difficult to distinguish from other types of rhinosinusitis. Besides, the characteristic infectious pathogeny of OMS makes it is resistant to conventional therapies of rhinosinusitis. Its current diagnosis and treatment are thus facing great difficulties. The multi-disciplinary cooperation between otolaryngologists and dentists is absolutely urgent to settle these questions and to acquire standardized diagnostic and treatment regimen for OMS. However, this disease has actually received little attention and has been underrepresented by relatively low publication volume and quality. Based on systematically reviewed literature and practical experiences of expert members, our consensus focuses on characteristics, symptoms, classification and diagnosis of OMS, and further put forward multi-disciplinary treatment decisions for OMS, as well as the common treatment complications and relative managements. This consensus aims to increase attention to OMS, and optimize the clinical diagnosis and decision-making of OMS, which finally provides evidence-based options for OMS clinical management.

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

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

Type 2 chronic inflammatory diseases: targets, therapies and unmet needs

Over the past two decades, significant progress in understanding of the pathogenesis of type 2 chronic inflammatory diseases has enabled the identification of compounds for more than 20 novel targets, which are approved or at various stages of development, finally facilitating a more targeted approach for the treatment of these disorders. Most of these newly identified pathogenic drivers of type 2 inflammation and their corresponding treatments are related to mast cells, eosinophils, T cells, B cells, epithelial cells and sensory nerves. Epithelial barrier defects and dysbiotic microbiomes represent exciting future drug targets for chronic type 2 inflammatory conditions. Here, we review common targets, current treatments and emerging therapies for the treatment of five major type 2 chronic inflammatory diseases - atopic dermatitis, chronic prurigo, chronic urticaria, asthma and chronic rhinosinusitis with nasal polyps - with a high need for targeted therapies. Unmet needs and future directions in the field are discussed.

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.

The Mechanism of Action and Clinical Efficacy of Low-Dose Long-Term Macrolide Therapy in Chronic Rhinosinusitis

Various chronic inflammatory airway diseases can be treated with low-dose, long-term (LDLT) macrolide therapy. LDLT macrolides can be one of the therapeutic options for chronic rhinosinusitis (CRS) due to their immunomodulatory and anti-inflammatory actions. Currently, various immunomodulatory mechanisms of the LDLT macrolide treatment have been reported, as well as their antimicrobial properties. Several mechanisms have already been identified in CRS, including reduced cytokines such as interleukin (IL)-8, IL-6, IL-1β, tumor necrosis factor-α, transforming growth factor-β, inhibition of neutrophil recruitment, decreased mucus secretion, and increased mucociliary transport. Although some evidence of effectiveness for CRS has been published, the efficacy of this therapy has been inconsistent across clinical studies. LDLT macrolides are generally believed to act on the non-type 2 inflammatory endotype of CRS. However, the effectiveness of LDLT macrolide treatment in CRS is still controversial. Here, we reviewed the immunological mechanisms related to CRS in LDLT macrolide therapy and the treatment effects according to the clinical situation of CRS.

S-Nitrosoglutathione Reduces the Density of Staphylococcus aureus Biofilms Established on Human Airway Epithelial Cells

Patients with chronic rhinosinusitis (CRS) often show persistent colonization by bacteria in the form of biofilms which are resistant to antibiotic treatment. One of the most commonly isolated bacteria in CRS is Staphylococcus aureus (S. aureus). Nitric oxide (NO) is a potent antimicrobial agent and disperses biofilms efficiently. We hypothesized that S-nitrosoglutathione (GSNO), an endogenous NO carrier/donor, synergizes with gentamicin to disperse and reduce the bacterial biofilm density. We prepared GSNO formulations which are stable up to 12 months at room temperature and show the maximum amount of NO release within 1 h. We examined the effects of this GSNO formulation on the S. aureus biofilm established on the apical surface of the mucociliary-differentiated airway epithelial cell cultures regenerated from airway basal (stem) cells from cystic fibrosis (CF) and CRS patients. We demonstrate that for CF cells, which are defective in producing NO, treatment with GSNO at 100 μM increased the NO levels on the apical surface and reduced the biofilm bacterial density by 2 log units without stimulating pro-inflammatory effects or inducing epithelial cell death. In combination with gentamicin, GSNO further enhanced the killing of biofilm bacteria. Compared to placebo, GSNO significantly increased the ciliary beat frequency (CBF) in both infected and uninfected CF cell cultures. The combination of GSNO and gentamicin also reduced the bacterial density of biofilms grown on sinonasal epithelial cells from CRS patients and improved the CBF. These findings demonstrate that GSNO in combination with gentamicin may effectively reduce the density of biofilm bacteria in CRS patients. GSNO treatment may also enhance the mucociliary clearance by improving the CBF.

Changes of the airway reactivity in patients with rhinosinusitis

Rhinosinusitis is one of the most common conditions in primary and secondary care all over the world. Rhinosinusitis together with asthma and gastroesophageal reflux disease represent the most common causes of chronic cough. The relationship between rhinosinusitis and cough is still not completely understood, however, direct stimulation of nasal mucosa, upper airway cough syndrome, inflammation of the airways, and cough reflex sensitisation play the crucial role in the pathogenesis of chronic cough.

Odontogenic Sinusitis: From Diagnosis to Treatment Possibilities-A Narrative Review of Recent Data

The maxillary sinus is a structure at the border of specialties: otorhinolaryngology and maxillofacial surgery. Due to this fact, regarding etiology, it can be affected by both the rhinogenic and odontogenic path and can impose diagnostic difficulties. The etiopathogenic mechanisms that can affect the Schneiderian membrane are mainly inflammatory, iatrogenic, traumatic, and tumorous in nature. From a microbiological point of view, the bacteriology is polymorphic, including both aerobic and anaerobic species in acute OS, the predominating species in acute OS being aerobic, and in chronic anaerobic germs. The role of fungi in the determination of this pathology and in the production of the biofilm that leads to resistance to antibiotic treatment is also discussed. The present paper aims to present the etiopathogenesis, bacteriology, clinical manifestations, as well as treatment of odontogenic sinusitis (OS) from an updated perspective through reviewing the literature. If unilateral maxillary sinusitis is usually due to odontogenic causes, this does not clinically exclude the possibility of strictly rhinogenic causes in the occurrence of sinusitis. This underlines the important role of complex oral and rhinological clinical examination as well as the role of preclinical examinations in specifying the certainty diagnosis. Simple radiography, orthopantomography, CT, and CBCT are compared in terms of diagnostic accuracy. The treatment of OS is complex, involving medication, dental, and surgical measures. The value of endoscopic surgery is emphasized, comparing its advantages over the classic Caldwell-Luc technique.

Biofilm and Planktonic Antibiotic Resistance in Patients With Acute Exacerbation of Chronic Rhinosinusitis

INTRODUCTION

The recalcitrant nature of patients with acute exacerbation of chronic rhinosinusitis (AECRS) potentially involves persisting colonization of the sinonasal mucosa by bacterial biofilms. Biofilms are known to be highly resistant to antibiotics, which may trigger or maintain chronic inflammation in the sinonasal mucosa. However, little is known about the relationship between the minimum inhibitory concentration (MIC) and antibiofilm concentrations of bacteria obtained from AECRS patients.

MATERIAL AND METHODS

Thirty bacterial strains from 25 patients with AECRS were identified and underwent MIC determination (VITEK^® 2). The planktonic isolates were submitted to an in vitro formation of biofilms (Modified Calgary Biofilm Device) and determination of minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) for amoxicillin, amoxicillin/clavulanic acid, clarithromycin, and levofloxacin. MIC of the planktonic forms was compared with MBIC and MBEC levels, according to the breakpoints established by the Clinical Laboratory Standards Institute guidelines.

RESULTS

The main bacteria retrieved was S. aureus (60%), followed by other Gram-positive and Gram-negative bacteria in lower frequencies. 76.7% of strains formed biofilm in vitro (n=23/30). The planktonic isolates presented high rates of resistance for amoxicillin (82.6%) and clarithromycin (39.1%), and lower rates for amoxicillin/clavulanic acid (17.4%). The biofilm-forming bacteria counterparts presented higher levels of MBIC and MBEC compared to the MIC levels for amoxicillin, amoxicillin/clavulanic acid, and clarithromycin. Levofloxacin was highly effective against both planktonic and biofilm forms. Planktonic resistant forms were associated with levels of antibiofilm concentrations (MBIC and MBEC).

CONCLUSIONS

Biofilm-forming bacteria from AECRS patients are prevalent, and biofilm forms are highly resistant to antibiotics compared to their planktonic counterparts. Antibiotic resistance observed in planktonic forms is a good indicator of biofilm resistance, although near 20% of susceptible planktonic bacteria can produce antibiotic tolerant biofilms.

Interactions between the foreign body reaction and Staphylococcus aureus biomaterial-associated infection. Winning strategies in the derby on biomaterial implant surfaces

Biomaterial-associated infections (BAIs) are an increasing problem where antibiotic therapies are often ineffective. The design of novel strategies to prevent or combat infection requires a better understanding of how an implanted foreign body prevents the immune system from eradicating surface-colonizing pathogens. The objective of this review is to chart factors resulting in sub-optimal clearance of Staphylococcus aureus bacteria involved in BAIs. To this end, we first describe three categories of bacterial mechanisms to counter the host immune system around foreign bodies: direct interaction with host cells, modulation of intercellular communication, and evasion of the immune system. These mechanisms take place in a time frame that differentiates sterile foreign body reactions, BAIs, and soft tissue infections. In addition, we identify experimental interventions in S. aureus BAI that may impact infectious mechanisms. Most experimental treatments modulate the host response to infection or alter the course of BAI through implant surface modulation. In conclusion, the first week after implantation and infection is crucial for the establishment of an S. aureus biofilm that resists the local immune reaction and antibiotic treatment. Although established and chronic S. aureus BAI is still treatable and manageable, the focus of interventions should lie on this first period.

Sinonasal Stent Coated with Slow-Release Varnish of Chlorhexidine Has Sustained Protection against Bacterial Biofilm Growth in the Sinonasal Cavity: An In Vitro Study

The aim of the study was to develop a sustained-release varnish (SRV) containing chlorhexidine (CHX) for sinonasal stents (SNS) to reduce bacterial growth and biofilm formation in the sinonasal cavity. Segments of SNS were coated with SRV-CHX or SRV-placebo and exposed daily to bacterial cultures of Staphylococcus aureus subsp. aureus ATCC 25923 or Pseudomonas aeruginosa ATCC HER-1018 (PAO1). Anti-bacterial effects were assessed by disc diffusion assay and planktonic-based activity assay. Biofilm formation on the coated stents was visualized by confocal laser scanning microscopy (CLSM) and high-resolution scanning electron microscopy (HR-SEM). The metabolic activity of the biofilms was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method. Disc diffusion assay showed that SRV-CHX-coated SNS segments inhibited bacterial growth of S. aureussubsp. aureus ATCC 25923 for 26 days and P. aeruginosa ATCC HER-1018 for 19 days. CHX was released from coated SNS segments in a pH 6 medium up to 30 days, resulting in growth inhibition of S. aureussubsp. aureus ATCC 25923 for 22 days and P. aeruginosa ATCC HER-1018 for 24 days. The MTT assay showed a reduction of biofilm growth on the coated SNS by 69% for S. aureussubsp. aureus ATCC 25923 and 40% for P. aeruginosa ATCC HER-1018 compared to the placebo stent after repeated exposure to planktonic growing bacteria. CLSM and HR-SEM showed a significant reduction of biofilm formation on the SRV-CHX-coated SNS segments. Coating of SNS with SRV-CHX maintains a sustained delivery of CHX, providing an inhibitory effect on the bacterial growth of S. aureussubsp. aureus ATCC 25923 and P. aeruginosa ATCC HER-1018 for approximately 3 weeks.

Revisiting the controversy: The role of fungi in chronic rhinosinusitis

In the last two decades, the development of culture-independent genomic techniques has facilitated an increased appreciation of the microbiota-immunity interactions and their role in a multitude of chronic inflammatory diseases such as chronic rhinosinusitis (CRS), asthma, inflammatory bowel disease and dermatitis. While the pathologic role of bacteria in chronic inflammatory diseases is generally accepted, the understanding of the role of fungi remains controversial. Chronic rhinosinusitis, specifically the phenotype linked to nasal polyps, represents a spectrum of chronic inflammatory diseases typically characterized by a type 2 immune response. Studies on the microbiota within sinus cavities from healthy and diseased patients have focused on the bacterial community, mainly highlighting the loss of diversity associated with sinus inflammation. Within the various CRS with nasal polyps (CRSwNP) phenotypes, allergic fungal rhinosinusitis presents an opportunity to investigate the role of fungi in chronic type 2 immune responses as well as the antifungal immune pathways designed to prevent invasive fungal diseases. In this review, we examine the spectrum of fungi-associated sinus diseases highlighting the interaction between fungal species and host immune status on disease presentation. With a focus on fungi and type 2 immune response, we highlight the current knowledge and its limitations of the sinus mycobiota along with cellular interactions and activated molecular pathways linked to fungi.

Current Perspective on Nasal Delivery Systems for Chronic Rhinosinusitis

Chronic rhinosinusitis is an upper respiratory disease during which topical drug treatment via the nasal cavity is the most actively utilized therapeutic strategy. In addition to steroids, antibiotics, and antifungal agents, which are widely used in clinical practice, research on novel topical agents to improve the bacterial biofilm or mucociliary clearance remains ongoing. Moreover, owing to the complex structure of the nasal cavity, the effects of nasal drug delivery vary depending on factors related to delivery fluid dynamics, including device, volume, and compounds. In this article, we review methods and compounds that have been applied to chronic rhinosinusitis management and introduce recent advances and future perspectives in nasal drug delivery for upper respiratory diseases.

Expression of Transcript Variants of PTGS1 and PTGS2 Genes among Patients with Chronic Rhinosinusitis with Nasal Polyps

To date, there has been no reliable test to identify unfavorable course of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), especially in aspirin intolerant patients. The research aimed to analyze the expression of transcript variants of PTGS1 and PTGS2 genes in the pathobiology of the disease. The study was performed on 409 adult patients: 206 CRSwNP patients including 44 (21.36%) aspirin intolerant patients and 203 healthy volunteers in the control group. Transcript variants of the PTGS1 and PTGS2 genes named as follows: COX1.1 for NM_000962, COX1.2 for NM_080591, COX1.3 for NM_001271165.1, COX1.4 for NM_001271368.1, COX1.5 for NM_001271166.1, COX2.1 for NM_000963.3, COX2.2 for AY_151286 and COX2.3 for BQ_722004 were confirmed using direct sequencing and quantified using targeted qPCR. The coexistence of all examined transcript variants in the study and the control group and significant differences between both were found. In aspirin sensitive patients, the levels of COX1.2, COX1.3, COX1.4 and COX1.5 isoforms were higher compared to aspirin-tolerant patients. The severity of symptoms was bigger in patients with higher expressions of variants: COX1.1 (R with dCt = −0.134; p = 0.0490), COX1.3 (R = −0.1429; p = 0.0400) and COX1.5 (Rs = −0.1499; p = 0.032). The expression of COX1.1 (Rs = −0.098; p = 0.049) and COX1.5 (Rs = −0.141; p = 0.043) isoforms increased with polyposis advancement in endoscopy. With the CT extent of sinuses opacification, COX1.1 isoform also significantly increased (Rs = −0.163; p = 0.020). The isoforms COX1.3, COX1.4, COX1.5 and COX2.1 may promote milder CRSwNP course. On the contrary, the variants COX1.1, COX1.2 and COX2.2 may be involved in a more aggressive disease.

Antibiofilm peptides: overcoming biofilm-related treatment failure

Health leaders and scientists worldwide consider antibiotic resistance among the world's most dangerous pathogens as one of the biggest threats to global health. Antibiotic resistance has largely been attributed to genetic changes, but the role and recalcitrance of biofilms, largely due to growth state dependent adaptive resistance, is becoming increasingly appreciated. Biofilms are mono- and multi-species microbial communities embedded in an extracellular, protective matrix. In this growth state, bacteria are transcriptionally primed to survive extracellular stresses. Adaptations, affecting metabolism, regulation, surface charge, immune recognition and clearance, allow bacteria to thrive in the human body and withstand antibiotics and the host immune system. Biofilms resist clearance by multiple antibiotics and have a major role in chronic infections, causing more than 65% of all infections. No specific antibiofilm agents have been developed. Thus, there is a pressing need for alternatives to traditional antibiotics that directly inhibit and/or eradicate biofilms. Host defence peptides (HDPs) are small cationic peptides that are part of the innate immune system to both directly kill microbes but also function to modulate the immune response. Specific HDPs and their derivatives demonstrate broad-spectrum activity against biofilms. In vivo biofilm assays show efficacy in abscess, respiratory, in-dwelling device, contact lens and skin infection models. Further progress has been made through the study of ex vivo organoid and air-liquid interface models to better understand human infections and treatment while relieving the burden and complex nature of animal models. These avenues pave the way for a better understanding and treatment of the underlying cause of chronic infections that challenge the healthcare system.

Bacterial Biofilm and its Role in the Pathogenesis of Disease

Recognition of the fact that bacterial biofilm may play a role in the pathogenesis of disease has led to an increased focus on identifying diseases that may be biofilm-related. Biofilm infections are typically chronic in nature, as biofilm-residing bacteria can be resilient to both the immune system, antibiotics, and other treatments. This is a comprehensive review describing biofilm diseases in the auditory, the cardiovascular, the digestive, the integumentary, the reproductive, the respiratory, and the urinary system. In most cases reviewed, the biofilms were identified through various imaging technics, in addition to other study approaches. The current knowledge on how biofilm may contribute to the pathogenesis of disease indicates a number of different mechanisms. This spans from biofilm being a mere reservoir of pathogenic bacteria, to playing a more active role, e.g., by contributing to inflammation. Observations also indicate that biofilm does not exclusively occur extracellularly, but may also be formed inside living cells. Furthermore, the presence of biofilm may contribute to development of cancer. In conclusion, this review shows that biofilm is part of many, probably most chronic infections. This is important knowledge for development of effective treatment strategies for such infections.

Identification and Characterization of Nasal Polyposis and Mycoplasma Superinfection by Scanning Electron Microscopy and Nasal Cytology with Optical Microscopy: A Case Report

Nasal polyposis is characterized by benign, non-cancerous and painless growths originating in the tissue of the nasal cavities and paranasal sinuses. Polyps arise from chronic inflammation due to asthma, recurrent infections, allergies, drug sensitivity or immune disorders. They can obstruct the nasal cavities and thus cause respiratory problems, a reduction in the sense of smell and susceptibility to infections. Furthermore, nasal polyps can recur. Hence the importance of using valid diagnostic methods. In this work, the diagnostic investigation carried out by scanning electron microscopy (SEM) and nasal cytology led, for the first time, to the identification of a mycoplasma superinfection on nasal polyposis.

The efficacy of diluted topical povidone-iodine rinses in the management of recalcitrant chronic rhinosinusitis: a prospective cohort study

PURPOSE

Recalcitrant chronic rhinosinusitis is a persistent inflammatory condition of the sinonasal mucosa despite adequate medical therapy and sinus surgery. This study aimed to demonstrate the effectiveness and safety of dilute povidone-iodine (PVP-I) sinonasal rinses as an adjunctive therapy.

METHODS

Prospective cohort study. Twenty-nine recalcitrant CRS patients with endoscopic evidence of ongoing inflammation and purulent discharge were prescribed 0.08% diluted PVP-I rinses. Changes to endoscopic modified Lund-Kennedy (MLK) scores at 7 weeks post-PVP-I rinsing served as the primary outcome measure.

RESULTS

The median MLK-discharge score significantly decreased in all patients by 1.50 points post-PVP-I rinsing (p value < 0.01). The total MLK score significantly decreased in all patients by 1.50 points (p value = 0.01). Up to a 17% reduction in serum inflammatory markers was measured post-PVP-I rinsing. Sinonasal culture revealed a shift from moderate-heavy growth to lighter bacterial growth overall. Subjective SNOT-22 scores significantly improved overall by ≥ 1 minimal clinically important difference (MCID > 12; baseline median = 33; follow-up median = 20; p value < 0.01; n = 22). TSH levels increased non-significantly within normal ranges (baseline median = 1.59 mU/L; follow-up median = 1.92 mU/L; p = 0.10; n = 15). Mucociliary clearance time increased non-significantly within normal ranges (baseline median = 9 min; follow-up median = 10 min; p value = 0.53; n = 17). Olfactory Sniffin'16 scores non-significantly decreased within age-related normal ranges (baseline median = 14; follow-up median = 13; p value = 0.72; n = 18).

CONCLUSION

A dilute 0.08% PVP-I sinonasal rinse as an ancillary therapy in recalcitrant CRS significantly reduces signs of infection alongside notable symptom improvement, without affecting thyroid function, mucociliary clearance or olfaction.