Treatment of chronic rhinosinusitis exacerbations due to methicillin-resistant Staphylococcus aureus with mupirocin irrigations

Temperature influences commensal-pathogen dynamics in a nasal epithelial cell co-culture model

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses, and microbial dysbiosis associated with CRS is thought to be a key driver of host inflammation that contributes to disease progression. Staphylococcus aureus is a common upper respiratory tract (URT) pathobiont associated with higher carriage rates in CRS populations, where S. aureus-secreted toxins can be identified in CRS tissues. Although many genera of bacteria colonize the URT, few account for the majority of sequencing reads. These include S. aureus and several species belonging to the genus Corynebacterium, including Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum, which are observed at high relative abundance in the healthy URT. Studies have examined bacterial interactions between major microbionts of the URT and S. aureus, but few have done so in the context of a healthy versus diseased URT environment. Here, we examine the role of temperature in commensal, pathogen, and epithelial dynamics using an air-liquid interface cell culture model mimicking the nasal epithelial environment. Healthy URT temperatures change from the nares to the nasopharynx and are increased during disease. Temperatures representative of the healthy URT increase persistence and aggregate formation of commensal C. propinquum and C. pseudodiphtheriticum, reduce S. aureus growth, and lower epithelial cytotoxicity compared to higher temperatures correlating with the diseased CRS sinus. Dual-species colonization revealed species-specific interactions between Corynebacterium species and S. aureus dependent on temperature. Our findings suggest URT mucosal temperature plays a significant role in mediating polymicrobial and host-bacterial interactions that may exacerbate microbial dysbiosis in chronic URT diseases.IMPORTANCEChronic rhinosinusitis is a complex inflammatory disease with a significant healthcare burden. Although presence of S. aureus and microbial dysbiosis are considered mediators of inflammation in CRS, no studies have examined the influence of temperature on S. aureus interactions with the nasal epithelium and the dominant genus of the healthy URT, Corynebacterium. Interactions between Corynebacterium species and S. aureus have been documented in several studies, but none to date have examined how environmental changes in the URT may alter their interactions with the epithelium or each other. This study utilizes a polarized epithelial cell culture model at air-liquid interface to study the colonization and spatial dynamics of S. aureus and clinical isolates of Corynebacterium from people with CRS to characterize the role temperature has in single- and dual-species dynamics on the nasal epithelium.

Clinical Practice Guideline: Nasal Irrigation for Chronic Rhinosinusitis in Adults

The Korean Society of Otorhinolaryngology-Head and Neck Surgery and Korean Rhinologic Society appointed a guideline development group (GDG) to establish a clinical practice guideline, and the GDG developed a guideline for nasal irrigation for adult patients with chronic rhinosinusitis (CRS). The guideline focuses on knowledge gaps, practice variations, and clinical concerns associated with nasal irrigation. Nasal irrigation has been recommended as the first-line treatment for CRS in various guidelines, and its clinical effectiveness has been demonstrated through a number of studies with robust evidence. However, no guidelines have presented a consistent nasal irrigation method. Several databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers using a predefined search strategy. When insufficient evidence was found, the GDG sought expert opinions and attempted to fill the evidence gap. Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. The committee developed 11 evidence-based recommendations. This guideline focuses on the evidence-based quality improvement opportunities deemed the most important by the GDG. Moreover, the guideline addresses whether nasal lavage helps treat CRS, what type of rinsing solution should be used, and the effectiveness of using additional medications to increase the therapeutic effect.

Rhinopharynx irrigations and mouthwash with dissolved mupirocin in treatment of MRSA throat colonization - proof-of-concept study

BACKGROUND

To prevent transmission of, and infection with, meticillin-resistant Staphylococcus aureus (MRSA), eradication treatment of colonized individuals is recommended. Throat colonization is a well-known risk factor for eradication failure. Staphylococcus aureus throat colonization is associated with colonization of the rhinopharynx, but in the currently recommended Danish MRSA eradication strategies, rhinopharynx colonization is not directly targeted. Rhinopharynx colonization could therefore be an important risk factor for prolonged MRSA throat carriage.

AIM

To determine whether irrigation and wash of the rhinopharynx and mouth with dissolved mupirocin is a feasible and potentially efficacious supplementary strategy against treatment-resistant MRSA throat carriage.

METHODS

The patient study was an open, non-blinded, trial including 20 treatment-resistant MRSA throat carriers. In the study, the patients received a supplementary treatment besides the standard treatment according to the Danish MRSA eradication strategy. The supplementary treatment consisted of rhinopharyngeal irrigation and mouth-gurgling twice a day for 14 days with a mupirocin ointment (22 g 2% ointment per litre of isotonic sterile saline solution) in a 37°C solution.

FINDINGS

Eighteen patients (90%) complied with the treatment protocol and none ex-perienced any major adverse events. Out of the 18 patients who finished the study per protocol, 15 (83%) and seven (39%) patients had negative MRSA sampling results one and six months after end of treatment, respectively.

CONCLUSION

This study demonstrates the feasibility and clinical potential of also targeting the rhinopharynx and oropharynx in non-systemic throat MRSA eradication strategies.

Tolerability and effectiveness of povidone-iodine or mupirocin versus saline sinus irrigations for chronic rhinosinusitis

OBJECTIVES

The role of topical anti-infectives in acute exacerbations of chronic rhinosinusitis is controversial. Povidone-iodine is an anti-bacterial and anti-viral that is affordable and available over-the-counter and may demonstrate advantages over mupirocin as a sinus irrigation therapy. The objective was to compare povidone-iodine or mupirocin versus saline sinus irrigations for sinusitis exacerbations in post-surgery subjects as well as to assess tolerability of povidone-iodine sinus irrigations.

MATERIALS AND METHODS

This was a prospective single-blinded (clinician only) randomized controlled trial. Subjects were post-surgery with acute exacerbations of chronic rhinosinusitis and gram-positive bacteria on culture. They received povidone-iodine, mupirocin, or saline sinus irrigations, twice daily for 30 days. Outcomes were post-treatment culture negativity (primary) and Sinonasal Outcome Test-20 and Lund-Kennedy endoscopic score change (secondary).

RESULTS

Of the 62 subjects analyzed, post-treatment culture negativity rate was higher in the MUP (14/20, 70%) group compared to the PI (9/21, 43%) and SAL (9/19, 47%) groups, although this was not significant (p = 0.29). Povidone-iodine sinus irrigations at the 1% concentration were very well-tolerated, similar to saline irrigations. There were no significant differences in Sinonasal Outcome Test-20 score (povidone-iodine -0.3 [-0.6, 0.05] vs. mupirocin -0.3 [-0.7, 0.05] vs. saline -0.4 [-0.8, 0.05]; p = 0.86) or Lund-Kennedy endoscopic score (povidone-iodine -3.5 [-7, -0.5] vs. mupirocin -2 [-4, 2] vs. saline -3 [-5, 0]; p = 0.45) change. No serious adverse effects were reported.

CONCLUSIONS

In patients who have had prior sinus surgery with acute exacerbations of CRS and gram-positive bacteria on culture, mupirocin sinus irrigations achieved a better post-treatment culture "control" rate compared to saline and povidone-iodine. In addition, 1% povidone-iodine solution was well-tolerated as a sinus irrigation and may represent a feasible method for temporarily disinfecting the sinonasal cavity of bacteria and viruses such as COVID-19.

Lysobacter enzymogenes LE16 autolysates have potential as biocontrol agents-Lysobacter sp. autolysates as biofungicide

AIMS

Biological techniques can manage plant diseases safely and in environmentally friendly ways, but their efficacy needs improvement. It is of the utmost importance to search for powerful microbes for the effective control of plant diseases.

METHODS AND RESULTS

Unheated self-digestive solutions (SDS) that were heated at 100°C for 30 min(H-SDS) or stored for 12 months at room temperature (S-SDS) were prepared from Lysobacter enzymogenes LE16 broth culture to study their potential as biocontrol agents. This bacterium produced protease, phosphatase, lysozyme and siderophores in pure culture as well as 12 secondary metabolites including novel antibiotics lysobactin, WAP-8294A₂ and mupirocin determined based on the antiSMASH 5.0.0 blast database. A poison plate assay revealed the antagonistic activities of SDS, H-SDS and S-SDS against an animal pathogenic bacterium Staphylococcus aureus, a phytopathogenic bacterium Pseudomonas syringae pv. tabaci, and numerous plant pathogenic fungi and oomycetes, including Colletotrichum gloeosporioides, Penicillium italicum, Alternaria alternate, Rhizoctonia solani, Didymella bryoniae, Sclerotinia sclerotiorum, Phytophthora nicotianae and Phytophthora capsici. The greenhouse experiment showed that SDS was highly effective in controlling pepper blight disease, which is caused by P. capsici. Compared with only pathogen inoculation, the application of SDS to the soil in preventive or curative treatments significantly reduced the disease incidence and index with relatively high control efficacy of 86·2-93·1%.

CONCLUSIONS

SDS enriched lytic enzymes, siderophores and antibiotics, has a wide antimicrobial spectrum, and shows potential as a new, safe and effective biocontrol agent against plant diseases.

SIGNIFICANCE AND IMPACT OF THE STUDY

Autolysates of the new biocontrol bacterium L. enzymogenes LE16 demonstrated the potential for industrial production and commercial use as a promising biocontrol agent in agriculture.

Topical antibiotic therapy in chronic rhinosinusitis: an update

BACKGROUND

Topical antibiotic therapies have been investigated for their use in chronic rhinosinusitis (CRS). However, society guidelines and evidence-based medicine reviews have recommended against the use of topical antibiotic therapy based on randomized controlled trials (RCTs). The purpose of this article is to review recent clinical research published since the aforementioned guidelines were published.

METHODS

A structured literature review was performed on clinical studies published in the last 5 years investigating the use of topical antibiotic therapies.

RESULTS

One double-blinded, randomized controlled trial (DB-RCT) supported the use of tobramycin using a vibrating aerosolizer; 1 non-blinded non-randomized controlled prospective trial lent support to use of topical ofloxacin for its anti-biofilm properties; and 1 meta-analysis found mupirocin irrigations to be beneficial in the short term. One Cochrane Review was unable to make a recommendation as no trial met the inclusion criteria. An additional systematic review found limited evidence to support the use of topical antibiotics with the exception of mupirocin irrigations that may be considered in Staphylococcus aureus infections. Two retrospective studies found that topical antibiotics change bacterial cultures of the sinuses.

CONCLUSION

There is additional evidence to support continuing investigation of topical antibiotic therapies. Further, larger RCTs are required to establish the efficacy of topical antibiotic therapies.

Exacerbations of Chronic Rhinosinusitis-Microbiology and Perspectives of Phage Therapy

The chronically inflamed mucosa in patients with chronic rhinosinusitis (CRS) can additionally be infected by bacteria, which results in an acute exacerbation of the disease (AECRS). Currently, AECRS is universally treated with antibiotics following the guidelines for acute bacterial rhinosinusitis (ABRS), as our understanding of its microbiology is insufficient to establish specific treatment recommendations. Unfortunately, antibiotics frequently fail to control the symptoms of AECRS due to biofilm formation, disruption of the natural microbiota, and arising antibiotic resistance. These issues can potentially be addressed by phage therapy. In this study, the endoscopically-guided cultures were postoperatively obtained from 50 patients in order to explore the microbiology of AECRS, evaluate options for antibiotic treatment, and, most importantly, assess a possibility of efficient phage therapy. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently isolated bacteria, followed by Haemophilus influenzae, Pseudomonas aeruginosa, and Enterobacteriaceae. Alarmingly, mechanisms of antibiotic resistance were detected in the isolates from 46% of the patients. Bacteria not sensitive to amoxicillin were carried by 28% of the patients. The lowest rates of resistance were noted for fluoroquinolones and aminoglycosides. Fortunately, 60% of the patients carried bacterial strains that were sensitive to bacteriophages from the Biophage Pharma collection and 81% of the antibiotic-resistant strains turned out to be sensitive to bacteriophages. The results showed that microbiology of AECRS is distinct from ABRS and amoxicillin should not be the antibiotic of first choice. Currently available bacteriophages could be used instead of antibiotics or as an adjunct to antibiotics in the majority of patients with AECRS.

The Role of Staphylococcus aureus in Patients with Chronic Sinusitis and Nasal Polyposis

PURPOSE OF REVIEW

Staphylococcus aureus (S. aureus) is correlated with the development of persistent severe inflammatory disease of the upper airway including chronic rhinosinusitis with nasal polyps (CRSwNP). The presence of S. aureus is associated with atopic disease including allergic rhinitis and atopic dermatitis and is associated with poor outcomes.

RECENT FINDINGS

Several different strains of S. aureus generate different toxins and gene products that can account for organism pathogenicity. S. aureus bacteria and its antigens shape the bacterial and fungal microbiome and the mucosal niche which generates host responses that can account for inflammation. The multiple disease phenotypes and molecular endotypes seen in CRSwNP can be characterized by T-helper cell environment within the inflammatory milieu, the presence of epithelial barrier dysfunction, aberrant eicosanoid metabolism, poor wound healing, and dysfunctional host-bacteria interactions which lead to recalcitrant disease and worse surgical outcomes. Understanding the pathomechanisms that S. aureus utilizes to promote nasal polyp formation, prolonged tissue inflammation, and bacterial dysbiosis are essential in our efforts to identify new therapeutic approaches to resolve this chronic inflammatory process.

Prevalence, severity, and risk factors for acute exacerbations of nasal and sinus symptoms by chronic rhinosinusitis status

BACKGROUND

Nasal and sinus symptoms (NSS) are common to many health conditions, including chronic rhinosinusitis (CRS). Few studies have investigated the occurrence and severity of, and risk factors for, acute exacerbations of NSS (AENSS) by CRS status (current, past, or never met European Position Paper on Rhinosinusitis [EPOS] criteria for CRS).

METHODS

Four seasonal questionnaires were mailed to a stratified random sample of Geisinger primary care patients. Logistic regression was used to identify individual characteristics associated with AENSS occurrence and severity by CRS status (current long-term, current recent, past, never) using EPOS subjective symptoms-only (EPOSS ) CRS criteria. We operationalized 3 AENSS definitions based on prescribed antibiotics or oral corticosteroids, symptoms, and symptoms with purulence.

RESULTS

Baseline and at least 1 follow-up questionnaires were available from 4736 subjects. Self-reported NSS severity with exacerbation was worst in the current long-term CRS group. AENSS was common in all subgroups examined and generally more common among those with current EPOSS CRS. Seasonal prevalence of AENSS differed by AENSS definition and CRS status. Associations of risk factors with AENSS differed by definition, but CRS status, body mass index, asthma, hay fever, sinus surgery history, and winter season consistently predicted AENSS.

CONCLUSIONS

In this first longitudinal, population-based study of 3 AENSS definitions, NSS and AENSS were both common, sometimes severe, and differed by EPOSS CRS status. Contrasting associations of risk factors for AENSS by the different definitions suggest a need for a standardized approach to definition of AENSS.

Topical Colloidal Silver for the Treatment of Recalcitrant Chronic Rhinosinusitis

Background: The management of recalcitrant chronic rhinosinusitis (CRS) is challenged by difficult-to-treat polymicrobial biofilms and multidrug resistant bacteria. This has led to the search for broad-spectrum non-antibiotic antimicrobial therapies. Colloidal silver (CS) has significant antibiofilm activity in vitro and in vivo against S. aureus, MRSA, and P. aeruginosa. However, due to the lack of scientific efficacy, it is only currently used as an alternative medicine. This is the first study looking at the safety and efficacy of CS in recalcitrant CRS.

Methods: Patients were included when they had previously undergone endoscopic sinus surgery and presented with signs and symptoms of sinus infection with positive bacterial cultures. Twenty-two patients completed the study. Patients were allocated to 10–14 days of culture directed oral antibiotics with twice daily saline rinses (n = 11) or 10 days of twice daily 0.015 mg/mL CS rinses (n = 11). Safety observations included pre- and post-treatment serum silver levels, University of Pennsylvania Smell Identification Test (UPSIT) and adverse event (AE) reporting. Efficacy was assessed comparing microbiology results, Lund Kennedy Scores (LKS) and symptom scores using Visual Analog Scale (VAS) and Sino-Nasal Outcome Test (SNOT-22).

Results: CS demonstrated good safety profile with no major adverse events, no changes in UPSIT and transient serum silver level changes in 4 patients. CS patients had 1/11 (9.09%) negative cultures, compared to 2/11 (18.18%) in the control group upon completion of the study. Whilst not statistically significant, both groups showed similar improvement in symptoms and endoscopic scores.

Conclusion: This study concludes that twice daily CS (0.015 mg/mL) sinonasal rinses for 10 days is safe but not superior to culture-directed oral antibiotics. Further studies including more patients and looking at longer treatment or improving the tonicity of the solution for better tolerability should be explored.

Topical therapy for refractory rhinosinusitis caused by methicillin-resistant Staphylococcus aureus: First report in a prospective series

OBJECTIVE

The incidence of refractory chronic rhinosinusitis (CRS) associated with methicillin-resistant Staphylococcus aureus (MRSA) is rising and remains a therapeutic challenge. The goal of this study is to demonstrate the efficacy of a non-invasive topical therapy against MRSA in these patients.

METHODS

Seventeen patients with refractory CRS caused by MRSA were treated with a topical therapy protocol. Treatment consisted of weekly endoscopic sinus debridement followed by intra-sinus installation of a hydroxyl-ethylcellulose gel that releases mometasone and a culture-directed antibiotic for a period of 6 weeks, along with daily nasal nebulization of mometasone with the same antibiotic and saline rinses. Clinical outcome was assessed using the Lund-Kennedy (LK) symptom and endoscopic appearance scores. Sinus mucosal tissue was homogenized and cultured, and microbial biofilm burden was assessed based on colony forming units (CFUs) counts.

RESULTS

Rhinotopic therapy resulted in clearance of MRSA in 13 of 16 patients (81.2%). Treated patients also demonstrated significant improvement clinically as measured by the LK scores. In addition, a significant decrease in mucosal CFUs was observed post-therapy.

CONCLUSION

Our findings demonstrate that topical therapy is an effective method for treating MRSA-associated refractory CRS.

Update on Intranasal Medications in Rhinosinusitis

This review describes beneficial effects and adverse events of various intranasal medications in treating rhinosinusitis. Application of intranasal steroids has been described in treating all subtypes of adult rhinosinusitis, but reports are limited in pediatrics and mostly in acute pediatric subgroups resulted in benefits While saline irrigation is effective for patients with chronic rhinosinusitis without polyps and in pediatric acute rhinosinusitis, there is no evidence yet for saline drips and sprays. Application of intranasal antifungals and nasal irrigation with surfactant brings more harm than benefits. There is no evidence supporting the use of intranasal antibiotics. We also review influence of devices, methods, and patient head position on nasal and paranasal sinus drug delivery.

Chronic rhinosinusitis: Endotypes, biomarkers, and treatment response

It is increasingly recognized that chronic rhinosinusitis (CRS) comprises a spectrum of different diseases with distinct clinical presentations and pathogenic mechanisms. Defining the distinct phenotypes and endotypes of CRS affects prognosis and, most importantly, is necessary as the basis for making therapeutic decisions. The need for individualized definitions of pathogenic mechanisms before initiating therapy extends to virtually all therapeutic considerations. This is clearly crucial with antibiotics, where, barring an influence from their off-target anti-inflammatory pharmacologic effects, an understanding of the role of the individual biome predicts likelihood of therapeutic benefit. However, this need for identifying individual phenotypes and endotypes also extends to the agent that is currently considered the mainstay of treatment of CRS, specifically glucocorticoids. As with asthma, it is recognized that a large minority of patients with CRS have a steroid-resistant phenotype, identification of which will preclude use of these agents with their potential side effects. Identification of endotypes is also becoming increasingly imperative because targeted biotherapeutic agents, such as anti-IgE and anti-cytokine antibodies, are becoming available. These agents are likely to benefit patients in whom the targeted mediator is not only expressed but demonstrably driving a central mechanism in that patient. In summary, the treatment of CRS is at an exciting crossroad. On the positive side, numerous therapeutics are in development that seem likely to have a positive effect in our patients with this condition. The challenge is that these therapies will require targeted individualized treatments based on identifying subjects with the relevant endotype.

Culture-directed topical antibiotic treatment for chronic rhinosinusitis

BACKGROUND

Topical antibiotics, delivered optimally as high-volume culture-directed sinus irrigations, are being increasingly used for recalcitrant chronic rhinosinusitis (CRS). Their impact on subjective and objective outcome measures, however, is still unclear.

OBJECTIVE

To assess if the use of topical antibiotics in recalcitrant CRS is associated with improved 20-Item Sino-Nasal Outcome Test and Lund-Kennedy endoscopic scores, and to determine the negative posttreatment culture "control" rate.

METHODS

Patients were included in the study if they met diagnostic criteria for CRS, received high-volume topical antibiotic sinus irrigations twice daily for 1 month, between December 2009 and May 2015, and had undergone endoscopic sinus surgery. The primary outcome was the 20-Item Sino-Nasal Outcome Test score. Secondary outcomes were the Lund-Kennedy endoscopic score and a negative posttreatment culture "control" rate. Paired t-tests were used to compare pre- and posttreatment scores. Patients with cystic fibrosis were analyzed separately.

RESULTS

Of the 58 patients included, 47% had nasal polyposis, 57% had asthma, 16% had aspirin sensitivity, and 55% had environmental allergies. The median Lund-Mackay computed tomography score was 11 (interquartile range, 6-16), and the median time to follow-up was 8 weeks (interquartile range, 6-10 weeks). The 20-Item Sino-Nasal Outcome Test scores improved from pre- to posttreatment period, although this was not significant mean 1.5 [confidence interval {CI} 1.3, 1.7] to mean 1.3 [CI 1.1, 1.6]; p = 0.16). Lund-Kennedy endoscopic scores, however, significantly improved from pre- to posttreatment (mean 4.9 [CI 4.3, 5.6] to mean 4.1 [CI 3.5, 4.7]; p = 0.05). Of the 47 patients with complete culture data, 72% had negative posttreatment culture results, defined as "controlled." Only one patient discontinued treatment, related to discomfort from irrigations.

CONCLUSION

In patients with recalcitrant CRS, the use of topical antibiotics trended toward improvement in symptom severity and significantly improved endoscopic appearance. Furthermore, 72% had negative posttreatment culture results, meaning microbiological "control." The results of this study support the use of high-volume culture-directed topical antibiotics, and, in the future, more rigorous prospective studies are warranted.

Mupirocin in the Treatment of Staphylococcal Infections in Chronic Rhinosinusitis: A Meta-Analysis

Background

Saline irrigation of the nasal cavity is a classic and effective treatment for acute or chronic rhinosinusitis. Topical antibiotics such as mupirocin have been widely used for recalcitrant chronic rhinosinusitis. Therefore, the purpose of this study was to evaluate the effect of saline irrigation using mupirocin.

Methods

A systematic literature review and meta-analysis of mupirocin saline irrigation were performed using EMBASE, MEDLINE, and Cochrane library through December 2015. Data were analyzed with R 3.2.2 software. A random effects model was used because of the diversity of included studies. Sensitivity analysis of particular tested groups and single proportion tests were also performed. The main outcome measure was residual staphylococcal infection, as confirmed by culture or PCR.

Results

Two RCTs, two prospective studies and two retrospective studies were included. A random effects model meta-analysis of the pooled data identified a relative risk of residual infection of 0.13 (95% CI: 0.06–0.26, p<0.05) with low heterogeneity (I² = 0%). The proportion of residual staphylococcal infections after 1 month was 0.08 (95% CI: 0.04–0.16). However, this proportion increased to 0.53 at 6 months (95% CI: 0.27–0.78).

Conclusions

The short-term use of mupirocin has a strongly reductive effect on staphylococcal infection in chronic rhinosinusitis. Although there is currently a lack of clear evidence, future studies with well-designed inclusion criteria and randomized controlled trials are needed to examine mupirocin’s long-term effect on 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.

Comparative study of the efficacy of topical steroid and antibiotic combination therapy versus oral antibiotic alone when treating acute rhinosinusitis

Background:

Acute rhinosinusitis arises as a consequence of viral rhinitis, and bacterial infection can subsequently occur. Intranasal antibiotics as an adjunct to corticosteroids usually demonstrate the greatest symptom relief.

Aim:

We wanted to clinically evaluate the effects of a topical antibiotic and steroid combination administered intranasally, versus an oral antibiotic alone when treating acute rhinosinusitis.

Method:

Forty patients with acute bacterial rhinosinusitis were divided into two groups. Group A received an antibiotic and steroid combination (ofloxacin 0.26 per cent and dexamethasone 0.053 per cent nasal drops) for 10 days, administered intranasally (5 drops in each nostril/8 hours). Group B, the control group, received an oral antibiotic alone (amoxicillin 90 mg/kg).

Results:

Eight hours after commencing treatment, facial pain was more severe in group B and nasal obstruction was reduced in both groups. Ten days after commencing treatment, anterior nasal discharge was 0.15 per cent in group A and absent in group B.

Conclusion:

The application of a topical antibiotic and steroid combination into the nasal cavity is an effective way of treating uncomplicated, acute bacterial rhinosinusitis with the theoretical advantages of easy administration, high local drug concentration and minimal systemic adverse effects.

Topical anti-infective sinonasal irrigations: update and literature review

BACKGROUND

Sinonasal anti-infective irrigations have emerged as a promising therapeutic modality in the comprehensive management of chronic rhinosinusitis (CRS), particularly in the context of recalcitrant disease. The purpose of this article was to delineate the current spectrum of topical anti-infective therapies available and evaluate their role in the treatment of CRS.

METHODS

A systematic literature review was performed on all studies investigating the use of topical antimicrobial solutions in the medical therapy of CRS. Anti-infective irrigations were stratified into topical antibacterial, antifungal, and additive preparations according to their composition and respective microbicidal properties.

RESULTS

The use of topical antibiotic irrigations has been supported by low-level studies in the treatment of refractory CRS, with optimal results achieved in patients who have undergone prior functional endoscopic sinus surgery and received culture-directed therapy. Multiple evidence-based reviews have not established any clinical benefit with the administration of topical antifungals, and their use is not currently recommended in the management of routine CRS. Topical additives including surfactants may be beneficial as adjunctive treatment for recalcitrant CRS, but additional research is needed to investigate their efficacy in comparison with other agents and establish safety profiles.

CONCLUSION

Topical anti-infective solutions are not recommended as first-line therapy for routine CRS but may be considered as a potential option for patients with refractory CRS who have failed traditional medical and surgical intervention. Additional research is necessary to determine which patient populations would derive the most benefit from each respective irrigation regimen and identify potential toxicities associated with prolonged use.

Lund-Mackay System for Computed Tomography Evaluation of Paranasal Sinuses in Patients with Granulomatosis and Polyangiitis

Granulomatosis with polyangiitis (GPA), a disease capable of affecting any organ, most often acts upon the upper respiratory tract. Diagnostic imaging is primarily represented by computed tomography (CT) of paranasal sinuses. The aim of this study was to define the characteristic changes in paranasal CT in patients with GPA and to evaluate diagnostic usefulness of the Lund-Mackey scoring system (L-M System). The study encompassed 43 patients with GPA of the mean age of 47.7 ± 12.8 years who were treated topically with mupirocin. We found that inflammation occurred mainly in the maxillary sinuses (72%). The mean L-M score was 5.8 ± 6.1. The right maxillary sinus had the highest percentage (12.6%) of score hits of 1, i.e., partial opacification and the left ostiomeatal complex had the highest percentage (7.6%) of score of 2, i.e., complete opacification or obstruction. The following changes were the most characteristic for GPA: sinus mucosal thickening, widespread bone damage, and osteogenesis. We conclude that the long-term topical mupirocin treatment of GPA may inhibit nasal bone damage, but also may led to permanent rhinological changes of the rhinosinusitis type. The Lund-Mackey staging system is a useful diagnostic imaging option in GPA patients.

Rising Methicillin-Resistant Staphylococcus aureus Infections in Ear, Nose, and Throat Diseases

The increasing incidence of methicillin-resistant Staphylococcus aureus infections (MRSA) in ENT diseases is becoming a big clinical concern. Here two patients are described who developed MRSA infections presented with unusual post-FESS epistaxis and postmastoidectomy perichondrial abscess and failed treatment with broad spectrum intravenous antibiotics. Following treatment with oral linezolid combined with local mupirocin dressing both patients fully recovered.

Role of biofilm in children with recurrent upper respiratory tract infections

Recurrent respiratory tract infections (RRTIs) are very common in children and a major challenge for pediatricians. In the last few years, bacterial biofilms have been linked to RRTIs and antibiotic resistance, and have raised serious concerns regarding the therapeutic management of recurrent middle ear diseases, chronic rhinosinusitis, and recurrent pharyngotonsillitis. This paper aims to review the new insights into biofilm-related upper respiratory tract infections in children and possible therapeutic strategies. It focuses on the clinical implications for recurrent disease and on studies in pediatric patients. Analysis of the literature showed that the involvement of bacterial biofilm in recurrent upper airway tract infections is an emerging problem that may lead to serious concerns about infection control. Despite the large amount of research within this field, detailed insight into the complex structure of bacterial biofilms and the ultrastructural and biochemical mechanisms responsible for its evasion of the immune system and resistance to treatments is currently lacking. In the future, additional emphasis should be placed on biofilm management as a component of therapeutic strategies. This goal can be attained by finding feasible methods for detecting biofilms in vivo and identifying effective methods for administering treatments that eradicate preexisting bacterial biofilms or hinder bacterial adhesion to respiratory cells.

Trends in incidence and susceptibility among methicillin-resistant Staphylococcus aureus isolated from intranasal cultures associated with rhinosinusitis

BACKGROUND

Reports regarding the incidence and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) in rhinosinusitis (RS) are limited. This study was designed to identify epidemiology and trends of MRSA incidence and antimicrobial resistance in the sinonasal cavities.

METHODS

This is a retrospective case series. All intranasal/sinus cultures obtained by otolaryngologists at Stanford over a 20-year period (1990-2010) were retrospectively reviewed by mining the microbiology database. Nested searches were then made for all S. aureus and MRSA cultures. Patterns of incidence and changes in antibiotic susceptibilities were tabulated and statistical analysis was performed.

RESULTS

Our search retrieved 10,387 positive intranasal culture samples, with S. aureus found in 800 (7.7%), and MRSA comprising 110 (1.06%) of this subset. Between the years of 1990 and 1999, only 2/112 (1.7%) of S. aureus-positive nasal cultures were positive for MRSA, with a sharp rise in incidence to 86/606 (14.2%) from 2000 to 2005, and to 22/82, 26.8% from 2006 to 2010. On a percent basis, using logistic regression modeling, this represents a statistically significant increasing trend (p < 0.0001) for MRSA sinusitis. However, over the 20-year interval studied, the patterns of antibiotic resistance among MRSA remained unaltered, especially with regard to trimethoprim-sulfamethoxazole and vancomycin.

CONCLUSION

S. aureus and MRSA isolates from intranasal cultures, which were essentially absent before the year 2000, became significantly more common earlier this decade. These data show the increased role of MRSA in sinusitis. MRSA antibiotic susceptibilities have remained, however, largely stable during this time period.

Biofilm Formations in Nasopharyngeal Tissues of Patients with Nasopharyngeal Osteoradionecrosis

Objective

Determine the presence of nasopharynx biofilms in patients with nasopharyngeal cancer (NPC) and osteoradionecrosis (ORN) and patients with NPC but no ORN.

Study Design

Cross-sectional study.

Setting

Tertiary referral medical center.

Subjects and Methods

We enrolled 27 patients with NPC from our outpatient clinic during January 2010 to June 2012. These patients were diagnosed with NPC between 1980 and 2012, and all had received radiotherapy. Of these 27 patients, 15 presented with ORN, and 12 did not. The nasopharynx biopsied specimens were processed and analyzed within 2 hours of collection with the FilmTracer LIVE_DEAD Biofilm Viability Kit (Molecular Probes, Invitrogen, Carlsbad, California). A blinded investigator determined the formation of biofilms by fluorescence microscopy. Bacterial cultures were collected.

Results

Eleven of 15 (73%) ORN patients had biofilm formations in nasopharynx biopsy specimens. Five of these samples (45%) yielded positive cultures, and 4 of these cultures indicated the presence of methicillin-resistant Staphylococcus aureus (MRSA). Only 1 of 12 NPC patients without ORN had nasopharynx biofilm formation, and all culture results were negative.

Conclusion

Biofilm formations were common in nasopharynx samples of NPC patients with ORN but rare in samples of NPC patients without ORN. The presence of biofilms, especially MRSA, may have a role in the disease progression of ORN or may contribute to the chronicity and resistance to antibiotic treatment.

Topical Drug Delivery for Chronic Rhinosinusitis

Chronic rhinosinusitis is a multifactorial disorder that may be heterogeneous in presentation and clinical course. While the introduction of endoscopic sinus surgery revolutionized surgical management and has led to significantly improved patient outcomes, medical therapy remains the foundation of long-term care of chronic rhinosinusitis, particularly in surgically recalcitrant cases. A variety of devices and pharmaceutical agents have been developed to apply topical medical therapy to the sinuses, taking advantage of the access provided by endoscopic surgery. The goal of topical therapy is to address the inflammation, infection, and mucociliary dysfunction that underlies the disease. Major factors that impact success include the patient's sinus anatomy and the dynamics of the delivery device. Despite a growing number of topical treatment options, the evidence-based literature to support their use is limited. In this article, we comprehensively review current delivery methods and the available topical agents. We also discuss biotechnological advances that promise enhanced delivery in the future, and evolving pharmacotherapeutical compounds that may be added to rhinologist's armamentarium. A complete understand of topical drug delivery is increasingly essential to the management of chronic rhinosinusitis when traditional forms of medical therapy and surgery have failed.

Topical therapies in the management of chronic rhinosinusitis: an evidence-based review with recommendations

BACKGROUND

Topical therapies have become an integral component in the management plan for chronic rhinosinusitis (CRS). Several topical therapy strategies have been evaluated, but a formal comprehensive evaluation of the evidence has never been performed. The purpose of this article is to provide an evidence-based approach for the utilization of topical therapies in the management of CRS.

METHODS

A systematic review of the literature was performed and the guidelines for development of an evidence-based review with recommendations were followed. Study inclusion criteria were: adult population >18 years old; chronic rhinosinusitis (CRS) based on published diagnostic criteria; and clearly defined primary clinical end-point. We focused on reporting higher-quality studies (level 2b or higher), but reported on lower-level studies if the topic contained insufficient evidence. We excluded drug-eluting spacer and stent therapy from this review.

RESULTS

This review identified and evaluated the literature on 5 topical therapy strategies for CRS: saline irrigation, topical steroid, topical antibiotic, topical antifungal, and topical alternatives (surfactant, manuka honey, and xylitol irrigations).

CONCLUSION

Based on the available evidence, sinonasal saline irrigation and standard topical nasal steroid therapy are recommended in the topical treatment of CRS. Nonstandard (off-label) topical sinonasal steroid therapies can be an option for managing CRS. The evidence recommends against the use of topical antifungal therapy and topical antibiotic therapy delivered using nebulized and spray techniques in routine cases of CRS. There is insufficient clinical research to provide recommendations for alternative therapies or topical antibiotic therapy delivered using other delivery methods (eg, irrigations).

A randomized trial of mupirocin sinonasal rinses versus saline in surgically recalcitrant staphylococcal chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

Chronic rhinosinusitis (CRS) recalcitrant to surgery is a frustrating clinical entity. Recently, mupirocin sinonasal rinses have been suggested as an efficacious treatment alternative in these patients where Staphylococcus aureus infection is demonstrated. To our knowledge, how best to treat this S aureus reservoir has not been previously evaluated in a double-blinded, randomized, placebo-controlled trial.

STUDY DESIGN

Prospective, double-blinded, placebo-controlled study.

METHODS

Twenty-five S aureus-positive CRS patients with persistent sinonasal infection despite endoscopic sinus surgery received either a 1-month, twice-daily treatment course of mupirocin sinonasal rinses (MUP) or saline rinses (CON). The primary outcome was S aureus-culture negativity at the conclusion of treatment; secondary rhinological outcomes included subjective and objective measures of rhinosinusitis.

RESULTS

Twenty-two patients satisfactorily completed the treatment period. Of CON patients, 0/13 (0.0%) returned an S aureus-negative sinonasal culture at 1 month, compared to 8/9 (88.9%) of MUP patients (P < .01). Improvements in rhinological outcomes observed in MUP patients following treatment were not subsequently evident when these patients were followed up at a delayed assessment 2 to 6 months after completing treatment.

CONCLUSIONS

Mupirocin sinonasal rinses are an effective short-term anti-S aureus treatment in surgically recalcitrant CRS as assessed by microbiological and selected rhinological outcomes, although the latter improvements may not be durable with time.

Bacteriology and antibiotic resistance in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent health care problem that may be commonly encountered in patients desiring aesthetic or reconstructive rhinoplasty. The purpose of this article is to review the common bacterial pathogens associated with CRS, as well as patterns of bacterial resistance in this patient subset. Close understanding of microbial pathogens involved in CRS and their associated resistance patterns will guide facial plastic surgeons in optimally managing this important potential comorbidity, and in turn positively influence the outcome of rhinoplasty.

Clinical application of treating biofilms-associated infections in family medicine

The management of common infections in family medicine may be complicated by poor treatment response or infection recurrence. In many cases, difficulty in treating these infections can be explained by the important role of biofilms, complex microbial communities with unique survival properties that promote infection resistance, recurrence, and persistence. Biofilms have been demonstrated to play important roles in infections involving the sinuses, ears, and ischemic wounds. Biofilms also commonly grow on medical devices, such as indwelling catheters, where they serve as an important nidus of persistent infection. Understanding the role of biofilms in medical infections suggests preventive and treatment strategies that will directly target the important resistive mechanisms of biofilms.

Community-acquired methicillin-resistant Staphylococcus aureus in nasal vestibular abscess

BACKGROUND

Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is a recognized entity that is increasingly responsible for skin and soft tissue infections. However, it is not the usual pathogen isolated in nasal vestibular abscess.

METHODS

We present a series of 13 consecutive patients presenting to a tertiary care center with nasal vestibular abscess over a 2.5-year period.

RESULTS

All abscesses were cultured and 100% (13/13) grew S. aureus. Of the S. aureus isolates, 92% (12/13) were MRSA. Antibiotic susceptibilities of the MRSA isolates were as follows: 100% were susceptible to rifampin, trimethoprim-sulfamethoxazole, and tetracycline, 75% to clindamycin, 58% to fluoroquinolones, and 17% to erythromycin.

CONCLUSION

MRSA is an important pathogen in the community. It is therefore critical to appreciate its potential predominance in nasal vestibular abscess. Clinicians should obtain cultures, modify antibiotic therapy as warranted, and initiate empiric therapy to include MRSA coverage for nasal vestibular abscess.

Eradicating chronic ear, nose, and throat infections: a systematically conducted literature review of advances in biofilm treatment

OBJECTIVE

Bacteria can grow as individual, planktonic organisms or as complex biofilm communities that are more resistant to treatment. This review was designed to systematically search to identify recent laboratory studies on eradication of biofilms in otolaryngologic infections to highlight promising advances in biofilm treatment.

DATA SOURCES

A systematic electronic literature search of Medline/PubMed, CINHAL, and Web of Science was conducted for articles describing the treatment of biofilm infections in ear, nose, and throat (ENT) diseases through March 2010. English-language articles and articles with an English abstract that focused on biofilm treatment were considered for review.

REVIEW METHODS

Each included article was reviewed by one of the authors for study design, treatment intervention, and outcome. Data from in vitro and animal studies were considered separately from human studies.

RESULTS

A total of 30 articles were identified for this review, including 5 studies that included a human treatment component. In general, antibiotics were relatively ineffective for eradicating biofilm infections. Markedly higher antibiotic dosages were required to reduce biofilm presence compared with doses that were effective in eradicating planktonic bacteria. Mupirocin irrigation, gentian violet, and thiamphenicol glycinate acetylcysteine effectively eradicated biofilms. Physical disruption, surfactants, and probiotics were also shown to be beneficial in both nonhuman and human studies.

CONCLUSION

Eradicating ENT biofilms is difficult when treating single-organism or mixed flora biofilms. Antibiotic therapy is often ineffective against biofilms, and clinical treatment may need to focus on nonantibiotic therapies that reduce, disrupt, or eradicate ENT biofilms.

Auditory Function After Application of Ototopical Vancomycin and Mupirocin Solutions in a Murine Model

Objective. To determine whether mupirocin (440 µg/mL) and vancomycin otic drops (25 mg/mL) show evidence of ototoxicity in CBA/J mice immediately following a 7-day course of daily intratympanic (IT) injections and 1 month following treatment.

Study Design. Nonrandomized controlled trial.

Setting. Academic hospital laboratory.

Subjects. Twenty CBA/J mice.

Results. Mean auditory brainstem response (ABR) thresholds increased in all drug- and saline-treated ears immediately after 7 days of IT injections but returned to baseline for most stimulus frequencies by 30 days later. This finding appeared to be correlated with the presence and subsequent resolution of tympanic membrane (TM) perforations and granulation tissue at the injection sites. Mupirocin-treated ears showed no significant difference in ABR thresholds compared to saline-treated ears. No significant differences were noted between vancomycin- and saline-treated ears, but there was a significant interaction between testing day and stimulus frequency ( P < .001). Further analysis revealed that ABR thresholds at 32 kHz remained significantly elevated in vancomycin-treated mice despite the resolution of TM perforations and granulation tissue 30 days after completion of IT injections (95% confidence interval, −13.5 to −5.5, P < .01).

Conclusion. Although IT application of mupirocin solution (440 µg/mL) caused no significant change in the ABR thresholds in a murine model, vancomycin solution (25 mg/mL) resulted in high-frequency threshold elevations in both the ear directly injected and the contralateral ear. Mupirocin solution may be beneficial in managing otitis externa and media caused by resistant pathogens. Further studies of ototopical vancomycin are needed to define parameters governing its safe use.

Bacteriology of recurrent exacerbation of postoperative course in chronic rhinosinusitis in relation to asthma

OBJECTIVES

Co-mobidity of asthma is known to result in a poor prognosis of post-endoscopic sinus surgery (post-ESS). Bacterial infection may play a key role in recurrent pathophysiology of sinusitis in post-ESS.

METHODS

Forty-two patients with CRS associated with asthma undergoing ESS were enrolled. Bacterial culture was performed from the sinus cavity at the time of acute infectious episodes. Recurrence of sinonasal disease was analyzed in terms of steroid responsiveness and peak expiratory flow (PEF).

RESULTS

Totally 75 aspirates were obtained during post-ESS; 2 repeat aspirates from 10 patients, 3 from 5 patients, and 4 from 2 patients. Only 6 specimens (8.0%) obtained from 5 patients (11.9%) showed no growth whereas 83 isolates were recovered from 69 specimens. Sixteen patients had at least one episode of a significant decline of PEF. All except one patient complained of symptoms and signs of upper respiratory infections prior to a depression of PEF. Positive culture was obtained in 10 out of 11 patients examined at the time of acute exacerbation of CRS.

CONCLUSION

Bacterial infection may play a critical role of recurrent polyps and refractory symptoms during post-ESS follow-up. Moreover, worsening of sinusitis accompanies asthma exacerbation.

Biofilms

Bacterial biofilms are 3-dimensional aggregates of bacteria that have been shown to play a major role in many chronic infections. Evidence is growing that bacterial biofilms may play a role in certain cases of recalcitrant chronic sinusitis that do not respond to traditional medical and surgical therapies. Novel therapies may have clinical applications to prevent and destabilize biofilms. Future research will determine if topical antimicrobials, surfactants, and other adjuvant therapies can be used to treat biofilm-associated chronic rhinosinusitis.

Sinogenic orbital and subperiosteal abscesses: Microbiology and methicillin-resistant Staphylococcus aureus incidence

OBJECTIVE: To assess the current bacteriology and the incidence of methicillin-resistant Staphylococcus aureus in orbital and subperiosteal abscesses of paranasal sinus disease origin.

STUDY DESIGN: Case series with chart review.

SETTING: An otolaryngology and ophthalmology specialty hospital.

SUBJECTS AND METHODS: Fifty-three patients were treated between 1994 and 2008 for orbital or subperiosteal abscess and paranasal sinusitis, confirmed by imaging and surgical intervention; 46 had operative culture specimens and comprise the study cohort.

RESULTS: The mean patient age was 28 years; one third were younger than 18. Nearly twice as many patients had subperiosteal (n = 30) as had orbital abscesses (n = 16). In 12 patients (26%), cultures were negative or grew only skin flora contaminants (coagulase-negative staphylococci, diphtheroids, and Propionibacterium acnes). Fifteen patients (33%) grew more than one pathogen. Streptococci were isolated in 17 of the 46 cases (37%), S. aureus in 13 (28.3%), gram-negative bacilli in eight (17.4%), and anaerobes in nine (19.6%). Methicillin-resistant S. aureus accounted for three (23.1%) of the S. aureus isolates and 6.5 percent of the total cases.

CONCLUSION: Abscess cultures grew a mixture of bacteria, including gram-positive cocci, gram-negative bacilli, and anaerobes. Although streptococci were the most common genus of bacteria isolated, S. aureus was the single most common pathogen recovered and one fourth of these cases were methicillin-resistant S. aureus. Given the significant morbidity that may result from inadequate treatment, an antibiotic active against methicillin-resistant S. aureus should be included in the initial broad-spectrum antimicrobial treatment regimen of orbital and subperiosteal abscesses of sinusitis origin until culture results are available.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Role of methicillin-resistant Staphylococcus aureus in head and neck infections

The prevalence of infection with methicillin-resistant Staphylococcus aureus is increasing. Methicillin-resistant Staphylococcus aureus is also being recognised as an important pathogen in head and neck infections. This review summarises studies published over the past two decades which illustrate the growing prevalence of methicillin-resistant Staphylococcus aureus, and the current therapeutic approaches to head and neck infections caused by this bacterium. These infections include sinusitis, otitis, periorbital cellulitis, cervical lymphadenitis, tonsillitis, thyroiditis, retropharyngeal abscess, and abscesses and wounds of the neck. Treatment of head and neck infections associated with methicillin-resistant Staphylococcus aureus includes drainage and debridement, as well as administration of local and systemic antimicrobials that provide coverage against these organisms and against potential aerobic and anaerobic pathogens that may be present if the infection is polymicrobial.

The role of allergy in rhinosinusitis

PURPOSE OF REVIEW

To examine the current evidence for IgE and non-IgE-mediated hypersensitivity mechanisms in acute and chronic rhinosinusitis.

RECENT FINDINGS

Epidemiological studies show that classical IgE-mediated allergy is present in a proportion of acute rhinosinusitis patients. There is conflicting evidence whether the prevalence of IgE-mediated allergy is greater in chronic rhinosinusitis than in individuals without chronic rhinosinusitis. Despite presence of classical IgE-mediated allergy, based on elevated allergen-specific serum IgE levels and positive skin prick tests, currently there is no direct evidence for allergy as a major cause of sinonasal inflammation in chronic rhinosinusitis. There is increasing evidence that non-IgE-mediated fungal hypersensitivity and nonallergic IgE-associated inflammation may contribute to the pathogenesis in some forms of chronic rhinosinusitis, including allergic fungal sinusitis. Specific IgE to bacterial superantigens may also be elevated in nasal polyps and modulate eosinophilic inflammation. Recent insights into mucosal immune mechanisms yield intriguing prospects for the roles of mucosal IgE, mast cells and non-IgE-mediated hypersensitivity mechanisms that require further examination in rhinosinusitis.

SUMMARY

There is a need for further immunological studies of the systemic and mucosal cellular and humoral mechanisms in well defined patient groups and controls to better understand the role of IgE and non-IgE-mediated hypersensitivity mechanisms and nonhypersensitivity functions of IgE in rhinosinusitis.

Biofilms in chronic rhinosinusitis: a review

BACKGROUND

Bacterial biofilms consist of a complex, organized community of bacteria that anchor to both biotic and abiotic surfaces. They are composed of layers of embedded, live bacteria within extruded exopolymeric matrix. This configuration allows for evasion of host defenses and decreased susceptibility to antibiotic therapy while maintaining the ability to deliberately release planktonic bacteria, resulting in recurrent acute infections. Thus, bacterial biofilms were hypothesized to contribute to the progression and persistence of chronic rhinosinusitis.

METHODS

This review summarizes several of the seminal papers supporting this hypothesis.

RESULTS

Multiple reports using various imaging modalities have demonstrated the presence of biofilms in sinonasal mucosa of patients with chronic rhinosinusitis. More recently, several studies have correlated the presence of biofilms with poor clinical outcomes in the disease process. Early therapeutic interventions have generated mixed results.

CONCLUSIONS

Bacterial biofilms appear to contribute to the progression of chronic rhinosinusitis in a subset of patients, although substantial effort toward therapeutic intervention is still necessary.

Trimethoprim-sulfamethoxazole for methicillin-resistant Staphylococcus aureus: a forgotten alternative?

Methicillin-resistant Staphylococcus aureus (MRSA) is a growing infectious concern, mainly in the context of its rapid adaptation to novel antibiotic options for its treatment and the growing morbidity, mortality, and healthcare costs associated with its emergence. the authors sought to investigate whether an older antibiotic, such as trimethoprim-sulfamethoxazole (SXT), may have a role in treating MRSA-related infections, according to the available literature on the subject. The authors reviewed literature data on: resistance of MRSA to SXT worldwide in recent years, efficacy of SXT for MRSA decolonization or prophylaxis from MRSA infections, and clinical therapeutic efficacy of SXT in treating mild or severe community-acquired or hospital-acquired MRSA infections. Resistance varies worldwide, in general being low in the industrialized world and higher in developing countries. SXT is one of the numerous understudied options for MRSA decolonization and is growingly recognized as potentially effective in preventing MRSA infections in certain settings. Limited data on its therapeutic efficacy are encouraging, at least for mild, community-acquired infections. SXT may represent a cost-effective alternative weapon against MRSA. Its utility against this increasingly threatening pathogen need clarification through further clinical trials.

Antimicrobial therapy in chronic rhinosinusitis

Antimicrobial therapy has been a mainstay of treatment for chronic rhinosinusitis (CRS). The roles of bacterial and fungal infection in the primary pathogenesis of CRS recently have been called into question. Although many different bacteria and fungi can be isolated from CRS patients, antimicrobial treatment directed at their eradication has met with mixed clinical results. Overall, macrolide antibiotics hold the most promise before surgery. Topical antibiotics are safe, efficient, and effective for treating acute bacterial exacerbations of CRS after endoscopic sinus surgery and may prevent the development of subsequent bacterial resistance. Topical treatment of CRS with antifungal agents both before and after sinus surgery is of limited benefit and should not be considered as a primary treatment modality before surgery. Further research into the role of bacterial and fungal infection in the pathophysiology of CRS may offer better insights into appropriate antimicrobial choices, dosing, and treatment duration.

The efficacy of topical antibiofilm agents in a sheep model of rhinosinusitis

BACKGROUND

Biofilms have been shown to be resistant to conventional antibiotic treatment. This study uses a sheep biofilm model developed by our department to investigate several novel topical anti-biofilm treatments.

METHODS

Staphylococcal biofilms were grown in 54 sheep frontal sinuses over 8 days: Each sinus was randomized to (1) no intervention, (2) single mupirocin flush, (3) regular 12-hourly mupirocin flushes for 5 days, (4) Citric Acid Zwitterionic Surfactant (CAZS) via hydrodebrider, (5) gallium nitrate, (6) CAZS with gallium nitrate, (7) CAZS with mupirocin, and (8) saline regular flushes. Sheep were sacrificed and the sinus mucosa harvested 1 or 8 days after treatment to assess treatment and any biofilm regrowth. Confocal scanning laser microscopy was used to confirm the presence or absence of biofilms, and the extent of biofilm reduction was quantitated using fluorescent in situ hybridization and colony forming unit counts.

RESULTS

In the control sheep biofilm coverage averaged 31.7%. Saline and mupirocin b.d. washes for 5 days had 23% and 0.84% coverage, respectively, when harvested on day 8. A single mupirocin and gallium wash had 7.7% and 16.2% on day 1 and 5.88% and 16.0% on day 8. CAZS with hydrodebrider had 6.66% on day 1 but 21.95% on day 8 whereas CAZS with hydodebrider and gallium had 13.3% on day 8.

CONCLUSION

This study shows that regular treatment with mupirocin produced the most marked reduction in biofilm surface area coverage (0.84% and 1.25%) with sustained effects over the 8-day follow-up period.

Are bulb syringe irrigators a potential source of bacterial contamination in chronic rhinosinusitis?

BACKGROUND

The purpose of this study was to determine if bulb syringe irrigators are a potential source for bacterial contamination in patients with chronic rhinosinusitis.

METHODS

Standard 3-oz bulb syringe irrigators (n = 24) were each flushed with the following solutions twice daily: A (n = 8), sterile isotonic saline; B (n = 8), prepared hypertonic saline (3 tsp table salt/L of sterile water); and C (n = 8), prepared baking soda/saline (1 tsp table salt + 1 tsp baking soda/L of commercial sterile water). Syringes were stored on a residential bathroom counter, and two from each group were harvested for culture weekly for 4 weeks.

RESULTS

There was no growth from syringes irrigated with any of the three solutions after the first 7 days of irrigation. After the entire 4-week study period, potential pathogens were recovered from 6/8 (75%) bulbs from group A, 0/8 bulbs from group B, and 1/8 bulbs (12.5%) from group C. All positive cultures revealed growth by 1-2 days postinoculation (p = 0.002). The organism recovered from syringes in group A was Pseudomonas fluorescens in all six specimens. The one positive culture in group C represented a single colony of Gram-positive cocci.

CONCLUSION

Under realistic conditions, bulb syringes are susceptible to contamination with potential bacterial pathogens, particularly when using unbuffered isotonic saline.