Staphylococcus aureus on Sinus Culture Is Associated With Recurrence of Chronic Rhinosinusitis After Endoscopic Sinus Surgery

Differential Nasal Recolonization and Microbial Profiles in Chronic Rhinosinusitis With Nasal Polyps Patients After Endoscopic Sinus Surgery or Dupilumab Treatment: A Prospective Observational Study

INTRODUCTION

The role of microbial profiles in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) pathogenesis is increasingly recognised, with microbial imbalances perpetuating inflammation. We performed this study to associate the different nasal microbiological profile changes with the response to surgical or monoclonal treatment.

METHODS

This prospective observational study evaluated changes in the nasal microbial profiles of 44 patients (22 dupilumab, 22 surgery) over 6 months. Clinical assessments were performed at baseline and follow-ups, including Sino-Nasal Outcome Test-22 (SNOT-22) scores and Sniffin Sticks-Identification (SS-I) olfactory testing. Microbial profiling of nasal swabs was carried out by microbial culture and subsequent molecular identification by Polymerase chain reaction (PCR) and sequencing.

RESULTS

Baseline characteristics of 44 patients (22 dupilumab, 22 surgery) enrolled in this study were similar between groups. In the dupilumab group, Staphylococcus epidermidis prevalence rose from 37.03% to 59.25%, while Pseudomonas aeruginosa was eradicated. Moreover, dupilumab stabilised Staphylococcus aureus at 63.64%, while its prevalence increased in the surgery group (from 22.72% to 50%). When bacterial groups were associated with clinical scores, P. aeruginosa carriers had worse SNOT-22 (21.00 ± 1.41) and SS-I (5.50 ± 0.71) scores. Instead, S. epidermidis-colonised patients exhibited significantly lower mean SNOT-22 (15.39 ± 8.54) and greater SS-I scores (8.39 ± 3.77). The best outcomes were found in the subgroup of S. epidermidis carriers undergoing the dupilumab treatment.

CONCLUSION

The two treatments modulated the microbial profiles differently, and, most importantly, clinical responses might depend on the association between treatment and the dominant bacterial species colonising the nasal cavity. Further investigation into microbial-restorative strategies could enhance outcomes for better treatment of CRS.

Staphylococcus aureus Phenol-Soluble Modulins Mediate Interspecies Competition with Upper Respiratory Commensal Bacteria

In chronic rhinosinusitis (CRS) disease, microbial dysbiosis is considered a key contributor to inflammation and pathogenicity, with increased prevalence of upper respiratory tract (URT) pathogens concomitant with decreased abundance of commensal species. Staphylococcus aureus is a common URT pathobiont associated with higher carriage rates in CRS. S. aureus secreted toxins are implicated in CRS pathogenesis, and toxins and antibodies to S. aureus secreted factors have been observed in tissue from CRS subjects. CRS disease severity is positively correlated with immune reactivity to S. aureus proteins. Prior studies have examined polymicrobial interactions between S. aureus and URT commensals, however, no studies to date have described possible methods employed by S. aureus to outcompete commensals leading to a S. aureus- dominant microbiome as seen in CRS. This study addresses this gap in knowledge by characterizing how a CRS-associated secreted toxin from S. aureus can inhibit aggregation in commensal URT species. Using a model URT commensal, Corynebacterium pseudodiphtheriticum , we identified a CRS-associated secreted protein from S. aureus , δ-toxin (Hld), that can inhibit C. pseudodiphtheriticum aggregation at biologically relevant concentrations. Furthermore, we observed recombinant δ-toxin reduces C. pseudodiphtheriticum adherence and aggregation on human nasal epithelial cells in an air-liquid interface cell culture model. These results define a novel mechanism by which S. aureus can disrupt URT commensal lifestyles of microbial competitors, contributing to the establishment of microbial dysbiosis.

IMPORTANCE

Microbial dysbiosis in the upper respiratory tract (URT) is associated with disease pathogenicity in chronic rhinosinusitis (CRS). There are significant links between Staphylococcus aureus and worse CRS outcomes, but no studies to date have demonstrated if S. aureus outcompetes other URT microbes through direct interactions. Here, we report that S. aureus δ-toxin, a secreted protein found in CRS patient tissue, can inhibit the ability of commensal bacteria to aggregate, adhere to, and grow in association with human nasal epithelial cells. These results suggest a potential mechanism for S. aureus to establish dominance in the URT microbiome through direct antagonism of commensals with a disease-associated toxin.

Mupirocin Ointment Effect on Polyposis Recurrence After Sinus Surgery

Introduction

Staphylococcus aureus is an identified pathogen involved in the recurrence of symptoms in patients with chronic rhinosinusitis with nasal polyps. We investigated the effectiveness of a topical ointment of mupirocin applied in the nasal vestibule in lessening symptom recurrence and improving the efficiency of functional endoscopic sinus surgery.

Materials and Methods

Patients with chronic rhinosinusitis, nasal polyps, and a positive nostril culture for Staphylococcus aureus were included in a clinical trial. The right nostril was determined as the intervention group (applying mupirocin ointment) and the left as the control group (applying vitamin A ointment). Lund-Mackay radiological scores and Lund-Kennedy endoscopic scores were examined at the time of diagnosis and six months later.

Results

Among 60 patients with chronic rhinosinusitis with nasal polyps, 91.6% were positive for nostril Staphylococcus aureus. Comparing the average of the diagnostic radiological and endoscopic scores with the follow-up values in both groups indicated a significant improvement after surgery (P-value=0.001, 0.001). However, there was no significant difference in the radiological and endoscopic score improvements between the study and control groups (P-value > 0.56, 0.74).

Conclusion

Nasal mupirocin administration following endoscopic sinus surgery cannot significantly prevent symptom recurrence in chronic rhinosinusitis with nasal polyps.

Efficacy and Safety of Xylitol Nasal Irrigation after Functional Endoscopic Sinus Surgery: A Randomized Controlled Study

Xylitol is considered a naturally occurring antibacterial agent. It is generally believed to enhance the body's own innate bactericidal mechanisms. It also provides anti-adhesive effects against both Streptococcus pneumoniae and Haemophilus influenza. This study was performed to evaluate the efficacy and safety of xylitol nasal irrigation in the postoperative care of functional endoscopic sinus surgery (FESS). Patients with chronic rhinosinusitis who received FESS were recruited and randomly assigned to two groups at one month post-surgery. Thirty-five patients in the xylitol group received 400 mL of 5% xylitol nasal irrigation daily for 2 months, while another 35 in the normal saline (NS) group received 400 mL of NS nasal irrigation daily for 2 months. Prior to FESS, as well as before and after nasal irrigation, sinonasal symptoms were assessed through the 22-item Sino-Nasal Outcome Test Questionnaire. The patients also underwent an endoscopic examination while undergoing nasal function tests, and a cytokine measurement of the nasal lavage and a bacterial culture from the middle meatus were performed. The safety of the nasal irrigation was assessed through any self-reported adverse events, the Eustachian Tube Dysfunction Patient Questionnaire and the eustachian tube function test. The endoscopic scores and olfactory threshold significantly decreased after xylitol irrigation when compared with those before irrigation. The prevalence of Staphylococcus aureus in the nasal secretions also decreased significantly after xylitol irrigation. The amounts of Interleukin-5 and Interleukin-17A were significantly increased in the nasal lavage after xylitol irrigation. No side effects, including those related to eustachian tube function, were seen after nasal irrigation in both groups. Our results showed that xylitol nasal irrigation was both beneficial and safe during the postoperative care of FESS.

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.

Rectal Staphylococcus aureus Carriage and Recurrence After Endoscopic Sinus Surgery for Chronic Rhinosinusitis With Nasal Polyps: A Prospective Cohort Study

OBJECTIVE

Chronic rhinosinusitis with nasal polyps (CRSwNPs) remains a major challenge due to its high recurrence rate after endoscopic sinus surgery (ESS). We aimed to investigate the risk factors of recurrence among patients who underwent ESS for Chronic rhinosinusitis (CRS).

METHODS

Prospective cohort study including 391 cases in a single institution receiving ESS were included for analysis from 2014 and 2017. Baseline characteristics including rectal Staphylococcus aureus (S aureus) carriage in patients receiving ESS for CRSwNPs. The primary outcome was the recurrence of CRSwNPs. Multivariate regression model was established to identify independently predictive factors for recurrence.

RESULTS

Overall, 142 (36.3%) cases with recurrence within 2 years after ESS were observed in this study. After variable selection, multivariate regression model consisted of 4 variables including asthma (odds ratio [OR] = 3.41; P < .001), nonsteroidal anti-inflammatory drug allergy (OR = 2.27; P = .005), previous ESS (OR = 3.64; P < .001), and preoperative carriage of S aureus in rectum (OR = 2.34; P = .001).

CONCLUSIONS

Based on our results, surgeons could predict certain groups of patients who are at high risk for recurrence after ESS. Rectal carriage of S aureus is more statistically related to the recurrence of CRSwNP after ESS compared with skin and nasal carriage.

Remission: does it already exist in chronic rhinosinusitis with nasal polyposis?

BACKGROUND

Remission, defined as absence of symptoms and objective markers of disease, is emerging as the penultimate goal in the management of several chronic diseases. The concept of remission, well-established in Rheumatology as well as Gastroenterology, is currently emerging in Respiratory Medicine for asthma. It is interesting to consider whether the disease remission concept might successfully be applied to Otolaryngology-Head and Neck Surgery in the management of chronic rhinosinusitis with nasal polyposis (CRSwNP).

OBJECTIVE

The purpose of this letter is to explore the evidence supporting the concept of remission under continued medical therapy in chronic rhinosinusitis with nasal polyposis.

METHODS

The authors reviewed the literature and summarized studies in chronic rhinosinusitis with nasal polyposis evaluating for evidence of clinical, biochemical, and endoscopic remission.

RESULTS

Findings of the studies revealed that endoscopic sinus surgery with continued medical therapy achieved remission in approximately 50% of all patients. CRSwNP patients after primary endoscopic sinus surgery were able to achieve remission in 72% of instances, however this drops to 42% for patients having revision sinus surgery. For CRSwNP patients with co-morbidities such as asthma and aspirin exacerbated respiratory disease, remission rate drops to 23% and 23.5%, respectively compared to non-asthmatic CRSwNP patients who present a remission rate under continued medical therapy of 60%.

CONCLUSION

Remission of symptoms and evidence of disease under medical therapy is indeed a concept achievable in patients with CRSwNP, as demonstrated by studies in the literature. Various co-morbidities, notably asthma, apparently influence rate of remission. Better defining this outcome through consensus-based definitions will allow for the development of strategies in CRSwNP care that can help affected patients attain complete relief from clinical, biochemical, and endoscopic markers of CRS with judicious use of medication and surgery. Future efforts will attempt to improve on these outcomes by achieving symptomatic and endoscopic control of disease following cessation of therapy, potentially paving the way towards clinical remission or a 'cure' in CRS.

The Changes in Bacterial Microbiome Associated with Immune Disorder in Allergic Respiratory Disease

Allergic respiratory disease is a worldwide and increasingly prevalent health problem. Many researchers have identified complex changes in the microbiota of the respiratory and intestinal tracts in patients with allergic respiratory diseases. These affect immune response and influence the progression of disease. However, the diversity of bacterial changes in such cases make it difficult to identify a specific microorganism to target for adjustment. Recent research evidence suggests that common bacterial variations present in allergic respiratory disease are associated with immune disorders. This finding could lead to the discovery of potential therapeutic targets in cases of allergic respiratory disease. In this review, we summarize current knowledge of bacteria changes in cases of allergic respiratory disease, to identify changes commonly associated with immune disorders, and thus provide a theoretical basis for targeting therapies of allergic respiratory disease through effective modulation of key bacteria.

Predicting the recurrence of chronic rhinosinusitis with nasal polyps using nasal microbiota

BACKGROUND

Recent studies have revealed that the nasal microbiota in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is profoundly altered and is correlated with systemic inflammation. However, little is known regarding whether the microbiota can be utilized to predict nasal polyp recurrence. This study is aimed to determine whether altered nasal microbiota constituents could be used as biomarkers to predict CRSwNP recurrence.

METHODS

Nasal microbiota constituents were quantified and characterized using bacterial 16S ribosomal RNA gene sequencing. Selected features for least absolute shrinkage and selection operator regression-based predictors were the nasal microbiota community composition and CRSwNP patient clinical characteristics. The primary outcome was recurrence, which was determined post-admission.

RESULTS

By distinguishing recurrence-associated nasal microbiota taxa and exploiting the distinct nasal microbiota abundance between patients with recurrent and non-recurrent CRSwNP, we developed a predictive classifier for the diagnosis of nasal polyps' recurrence with 91.4% accuracy.

CONCLUSIONS

Key taxonomical features of the nasal microbiome could predict recurrence in CRSwNP patients. The nasal microbiome is an understudied source of clinical variation in CRSwNP and represents a novel therapeutic target for future prevention and treatment.

The Effect of Radiation and Chemoradiation Therapy on the Head and Neck Mucosal Microbiome: A Review

Radiation (RT) and chemoradiation therapy (CRT) play an essential role in head and neck cancer treatment. However, both cause numerous side effects in the oral cavity, paranasal sinuses, and pharynx, having deleterious consequences on patients’ quality of life. Concomitant with significant advances in radiation oncology, much attention has turned to understanding the role of the microbiome in the pathogenesis of treatment-induced tissue toxicity, to ultimately explore microbiome manipulation as a therapeutic intervention. This review sought to discuss current publications investigating the impact of RT and CRT-induced changes on the head and neck microbiome, using culture-independent molecular methods, and propose opportunities for future directions. Based on 13 studies derived from a MEDLINE, EMBASE, and Web of Science search on November 7, 2021, use of molecular methods has uncovered various phyla and genera in the head and neck microbiome, particularly the oral microbiome, not previously known using culture-based methods. However, limited research has investigated the impact of RT/CRT on subsites other than the oral cavity and none of the studies aimed to examine the relationship between the head and neck microbiome and treatment effectiveness. Findings from this review provide helpful insights on our current understanding of treatment-induced oral mucositis, dental plaque, and caries formation and highlight the need for future research to examine the effect of RT/CRT on the sinonasal and oropharyngeal microbiome. In addition, future research should use larger cohorts, examine the impact of the microbiome on treatment response, and study the effect of manipulating the microbiome to overcome therapy resistance.

Review: The Nose as a Route for Therapy. Part 2 Immunotherapy

The nose provides a route of access to the body for inhalants and fluids. Unsurprisingly it has a strong immune defense system, with involvement of innate (e.g., epithelial barrier, muco- ciliary clearance, nasal secretions with interferons, lysozyme, nitric oxide) and acquired (e.g., secreted immunoglobulins, lymphocytes) arms. The lattice network of dendritic cells surrounding the nostrils allows rapid uptake and sampling of molecules able to negotiate the epithelial barrier. Despite this many respiratory infections, including SARS-CoV2, are initiated through nasal mucosal contact, and the nasal mucosa is a significant "reservoir" for microbes including Streptococcus pneumoniae, Neisseria meningitidis and SARS -CoV-2. This review includes consideration of the augmentation of immune defense by the nasal application of interferons, then the reduction of unnecessary inflammation and infection by alteration of the nasal microbiome. The nasal mucosa and associated lymphoid tissue (nasopharynx-associated lymphoid tissue, NALT) provides an important site for vaccine delivery, with cold-adapted live influenza strains (LAIV), which replicate intranasally, resulting in an immune response without significant clinical symptoms, being the most successful thus far. Finally, the clever intranasal application of antibodies bispecific for allergens and Intercellular Adhesion Molecule 1 (ICAM-1) as a topical treatment for allergic and RV-induced rhinitis is explained.

Staphylococcus aureus Infection and Persistence in Chronic Rhinosinusitis: Focus on Leukocidin ED

Chronic rhinosinusitis (CRS) is thought to be a multifactorial disease that includes a direct involvement of bacteria that trigger inflammation and contribute to CRS pathogenesis. Staphylococcus aureus infection and persistence is associated with chronic rhinosinusitis (CRS), and it may be particularly relevant in the form with nasal polyps (CRSwNP). The large array of exotoxins deployed by S. aureus is instrumental for the bacterium to warrant its infection and dissemination in different human body districts. Here, we analyze the common Th2 environment in CRSwNP and prospect a possible dynamic role played by S. aureus leukocidins in promoting this chronic inflammation, considering leukocidin ED (LukED) as a strong prototype candidate worth of therapeutic investigation. CCR5 is an essential target for LukED to exert its cytotoxicity towards T cells, macrophages and dendritic cells. Therefore, CCR5 blockade might be an interesting therapeutic option for CRS and, more specifically, persistent and relapsing CRSwNP. In this perspective, the arsenal of CCR5 antagonists being developed to inhibit HIV-1 entry (CCR5 being the major HIV-1 co-receptor) could be easily repurposed for CRS therapeutic investigation. Finally, direct targeting of LukED by neutralizing antibodies could represent an important additional solution to S. aureus infection.

Azithromycin in high-risk, refractory chronic rhinosinusitus after endoscopic sinus surgery and corticosteroid irrigations: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Refractory chronic rhinosinusitis (CRS) remains a significant burden for patients, often leaving them with few therapeutic options that provide low-morbidity, long-term, and meaningful symptomatologic and endoscopic disease improvement. Macrolides have long been thought to offer both an immunomodulatory and antimicrobial effect. Our objective was to evaluate the efficacy of low-dose, long-term azithromycin in a carefully selected high-risk population failing appropriate medical therapy of budesonide nasal irrigations (BNIs) and endoscopic sinus surgery (ESS).

METHODS

A double-blind, randomized, placebo-controlled trial was completed in a single tertiary-care center assessing the addition of 250 mg azithromycin, 3 times per week for 16 weeks, in adults failing ESS and high-volume BNIs. Associated comorbidities, as well as symptomatologic, microbiologic, and serologic values, were systematically collected.

RESULTS

A total of 128 patients were enrolled and underwent ESS followed by BNI. At the 4-month post-ESS visit, 48 patients showed disease persistence and were randomized to azithromycin or placebo. Overall, azithromycin, when compared with placebo, did not show a statistically significant difference in disease clearance (54% vs 33%, respectively; p = 0.146), although patients with disease clearance who were on azithromycin showed significantly better 22-item Sino-Nasal Outcome Test score improvements than patients on placebo (18 vs -0.9, respectively; p = 0.046). In a subgroup analysis excluding aspirin-exacerbated respiratory disease (AERD) patients, azithromycin significantly improved disease clearance when compared with placebo (71% vs 35%, respectively; p = 0.031), with a number needed to treat of 3 (2.8).

CONCLUSION

Low-dose azithromycin is a therapeutic option with few side effects. Its use can show favorable clinical outcomes in this difficult-to-treat population, especially if patients are AERD-negative.

Low-dose and long-term azithromycin significantly decreases Staphylococcus aureus in the microbiome of refractory CRS patients

BACKGROUND

The sinonasal microbiome is believed to play an important role in the pathophysiology of refractory chronic rhinosinusitis (CRS). We evaluated changes in the microbiome following a 4-month course of low-dose azithromycin. Assessing microbiome alterations following such a treatment may help identify underlying mechanisms of this drug.

METHODS

A total of 48 adults with refractory CRS were enrolled in a double-blind, randomized, placebo-controlled trial. Patients were randomized to 250 mg of azithromycin or placebo 3 times weekly for 4 months. During this time, daily budesonide saline irrigations were continued. Sinonasal swabs were collected by endoscopically-assisted method prior to treatment initiation and at the end of it, and sent for 16S ribosomal RNA gene sequencing. High-resolution ANCHOR pipeline was used to infer and annotate putative species. The 2 patient groups were compared using DESeq2 differential abundance analysis.

RESULTS

From initiation to the end of azithromycin treatment, patients showed a significant difference in beta diversity analysis (p = 0.0004) along with a significant decrease in 71 different operational taxonomic units (OTUs) of Staphylococcus aureus (false discovery rate [FDR] < 0.05) obtained from the differential abundance analysis. This was not observed in placebo-treated patients. By the end of treatments, azithromycin-treated patients had a significant decrease in 29 different OTUs of S. aureus (FDR < 0.05) when compared to placebo.

CONCLUSION

A 4-month course of 250 mg of azithromycin 3 times weekly in patients with refractory CRS significantly decreases S. aureus abundance in the sinonasal microbiome. Considering the pathogenic role of S. aureus in the refractory CRS population, azithromycin may constitute an additional therapeutic option to help control this disease.