Role of bacterial biofilm in development of middle ear effusion

Investigating the epidemiological relevance of secretory otitis media and neighboring organ diseases through an Internet search

Background

This study examined the epidemiological correlations between secretory otitis media (SOM) and diseases of neighboring organs. We measured changes in disease incidences during the 2020 COVID-19 pandemic using Internet big data spanning from 2011 to 2021.

Methods

This study used the Baidu Index (BI) to determine the search volume for the terms "secretory otitis media (SOM)", "tonsillitis", "pharyngolaryngitis", "adenoid hypertrophy (AH)", "nasopharyngeal carcinoma (NPC)", "nasal septum deviation (NSD)", "rhinosinusitis", "allergic rhinitis (AR)", and "gastroesophageal reflux disease (GERD)" in Mandarin from January 2011 to December 2021. The correlations between these terms were analyzed using Spearman's correlation coefficients. The results were compared search data from 2019 and 2021 to assess the effects of isolation on SOM in 2020.

Results

The seasonal variations trends of SOM and other diseases coincided well (P < 0.05), except for AR. During the 11-year timeframe, the monthly searches for rhinosinusitis, NSD, tonsillitis, pharyngolaryngitis, and NPC were statistically correlated with SOM (R = 0.825, 0.594, 0.650, 0.636, 0.664, respectively; P < 0.05). No correlation was found between SOM and AR, SOM and AH, or SOM and GERD (R =  - 0.028, R = 0.259, R = 0.014, respectively, P > 0.05). The total search volumes for SOM, rhinosinusitis, NPC, and AH decreased in 2020 compared to 2019.

Discussion

SOM exhibited a discernible epidemiological connection with rhinosinusitis, nasal septal deviation (NSD), tonsillitis, pharyngolaryngitis, and nasopharyngeal carcinoma (NPC). A decrease in public gatherings was observed to effectively reduce the incidences of SOM. This underscores the pivotal role of social measures in influencing the prevalence of SOM and emphasizes the intricate interplay between SOM and various associated health factors, with implications for public health strategies.

The Prevalence and Association of Biofilms With Otitis Media With Effusion: A Systematic Review and Meta-Analysis

PURPOSE

We aimed to identify the role of bacterial biofilms in the chronicity of otitis media with effusion and its resistance to antibiotics. We illustrated this role by reviewing, analyzing, and correlating the findings with the results of the included studies to reach clear evidence.

METHODS

A comprehensive search of electronic databases (Scopus, PubMed, Web of Science, Cochrane, and GHL databases) was performed for all studies using the following strategy till April 2021 with the search terms: Biofilm and Middle ear effusion. We found 935 references, 421 were duplicates, and 514 were needed for further screening, and it was as follows: PubMed 215, Scopus 18, Cochrane 130, Web of Science 136, and GHL 15.

RESULTS

The pooled prevalence of culture-positive effusions was estimated to be 40% (95% CI [28%, 53%]) of the total OME population. Overall, the prevalence of PCR-positive effusions was estimated to be 97% (95% CI [95%, 99%]) of the total OME population. The pooled prevalence of EM-positive effusions was estimated to be 82% (95% CI [69%, 95%]) of the total OME population.

CONCLUSION

The data presented in this study coincide with the significant role of bacterial biofilms in the pathogenesis of chronic otitis media with effusion. The involvement of bacterial biofilm as a component of the OME pathogenic process can help us to explain why antimicrobial therapy is not always effective in the eradication of the disease process and, also explain the recurrence of middle ear effusion after treatment with tympanostomy tubes either with or without adenoidectomy.

The influence of nasal and oropharyngeal mucosal dysbiosis on the condition of the middle ear in children with congenital cleft palate

Disturbance of the microbiocenosis of the nasal cavity and oropharynx in children with congenital cleft palate presents serious therapeutic difficulties. Pathobionts colonizing the upper respiratory tract and chronic adenoiditis pose a threat of acute purulent otitis media and chronic otitis media with effusion. The authors studied nasal and oropharyngeal mucosal dysbiosis in patients before elective uranoplasty and the effect of dysbiotic manifestations on the condition of the middle ear in the postoperative period. The results of microbiological examination of 80 swabs from the nasal cavity and oropharynx in patients with congenital cleft palate were analyzed. Among the culture-positive results in patients in clinical and laboratory remission of ENT-infections dysbiosis of 2–3 degrees prevails, the presence of bacterial-bacterial and bacterial-fungal associations is often noted, the predominance of gram-negative microflora is noted. There was an increase in the frequency of perforations of the tympanic membrane in the presence of bacterial and fungal associations, the appearance of retraction pockets in the presence of gram-negative microflora, the relationship between grade 3 dysbiosis and the appearance of purulent otitis media after uranoplasty were revealed.

Conclusion. Disturbance of microbiocenosis in patients with congenital cleft palate before uranoplasty requires the inclusion of a microbiological study in the preoperative preparation schedule and a personalized approach to perioperative antibiotic prophylaxis. 

Tympanoplasty and adenoidectomy in children: Comparison of simultaneous and sequential approaches

Background

The authors sought to compare simultaneous and sequential tympanoplasty and adenoidectomy surgery in pediatric patients.

Methods

This retrospective single-center study included 65 children (36 males, 29 females; mean age 9.16 ± 3.82 years; range 3–17 years) requiring both tympanoplasty and adenoidectomy. Simultaneous surgeries were performed on the same day, during single general anesthesia, whereas sequential surgeries were separated at least 12 weeks. The groups were compared with regard to restoration of hearing, tympanic membrane status, and utilization of medical resources. All study participants had a 12-months follow-up period after surgery.

Results

No statistically significant differences were observed between the groups regarding pre- and post-operative ABG values and average hearing gains. However, the post-operative ABG was significantly lower than the pre-operative ABG in both groups (p<0.001). There were no significant differences between simultaneous and sequential groups with respect to complete healing rates and complications (all p>0.355). Simultaneous tympanoplasty and adenoidectomy surgery management is associated with a significantly decreased cumulative hospital stay, cumulative operating room time, and cumulative pure surgical time (all p≤0.016).

Conclusions

The results of first comparative study of simultaneous versus sequential tympanoplasty and adenoidectomy surgery managements demonstrate no advantages for the sequential approach. The same-day surgery can show the clinical outcomes comparable to those in the sequential group. The simultaneous surgery approach appears to be associated with reduced medical resources consumption. Therefore, simultaneous surgery management is an effective and safe option for children with chronic otitis media and adenoid hypertrophy.

IL-17 is a Potential Therapeutic Target in a Rodent Model of Otitis Media with Effusion

Background

Otitis media with effusion (OME) is a non-suppurative inflammation of the middle ear that is characterized by middle ear effusion and hearing loss. However, the mechanisms of OME are not fully understood. The aim of this study was to determine the function and the mechanism of the IL-17 cytokine in the pathogenesis of OME and to investigate IL-17 as a potential strategy for the treatment of OME.

Methods

In this study, the OME rat model was induced by ovalbumin (OVA) as previously described. The severity of OME was determined with an oto-endoscope, by histochemical analysis, and by acoustic immittance. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of RNA-sequencing (RNA-seq) data was carried out to analyze the signaling pathways related to the pathogenesis of OME, which indicated that IL-17 is involved in OME. The anti-IL-17A monoclonal antibody was administrated by nasal drip to block IL-17 to treat OME in the rat model. The rats were finally injected intraperitoneally with the inhibitor of Notch signaling pathway to study the mechanisms of IL-17-induced inflammation. Serum and lavage fluid were collected for the detection of related cytokines, and middle ear tissue was collected for Western blot, quantitative real-time PCR (qRT-PCR), and immunohistochemical and immunofluorescence analysis.

Results

KEGG analysis of RNA-seq data suggested that the IL-17 signaling pathway might be involved in the onset of OME. IL-17 expression was confirmed to be increased in both the serum and the middle ear of the rat model. The monoclonal antibody against IL-17 neutralized IL-17, inhibited the inflammation in the middle ear, and reduced the overall severity of OME in vivo. Furthermore, the Notch signaling pathway was activated upon IL-17 upregulation in OME and was suppressed by IL-17 blockage. However, there was no change in IL-17 expression after Notch inhibitor treatment, which reduced the severity of OME in the rat middle ear.

Conclusion

IL-17 plays a key role in the pathogenesis of the OVA-induced OME rat model. IL-17 induced inflammatory responses via the Notch signaling pathway and targeting IL-17 might be an effective approach for OME therapy.

The role of thymic stromal lymphopoietin in the development of chronic otitis media with effusion

PURPOSE

To investigate the effect of thymic stromal lymphopoietin on the development of chronic otitis media with effusion MATERIALS AND METHODS: This study was conducted on 40 patients who had adenoidectomy operation. The objects were divided into two groups. Group 1; adenoidectomy with chronic serous otitis media, group 2; adenoidectomy without chronic serous otitis media. Serum and tissue thymic stromal lymphopoietin levels were measured by ELISA. Serum and tissue TLSP levels, mast cell count, adenoid size were compared between the groups.

RESULTS

Twenty-four (60%) of patients were female and 16 (40%) were male. Twenty patients (55%) had adenoid hypertrophy with chronic serous otitis media, and 18 (45%) had adenoid hypertrophy without chronic serous otitis media. The mean age of the patients was 6.21 ± 2.31 years. The mean mast cell count was significantly higher in group 1 compared with group 2 (p = 0.017). The mean tissue thymic stromal lymphopoietin measurement was also significantly higher in group 1 than group 2 (p = 0.023). However, there was no significant difference in regards to serum levels between the groups (p = 0.480).

CONCLUSION

The number of mast cells as well as thymic stromal lymphopoietin levels in the adenoids of children was significantly high in the chronic serous otitis media patients. The release of thymic stromal lymphopoietin from the adenoid tissue plays a role in initiating and maintaining a local inflammatory reaction in the eustachian tube that may lead eventually to middle ear effusion in non-atopic patients.

Handheld Briefcase Optical Coherence Tomography with Real-Time Machine Learning Classifier for Middle Ear Infections

A middle ear infection is a prevalent inflammatory disease most common in the pediatric population, and its financial burden remains substantial. Current diagnostic methods are highly subjective, relying on visual cues gathered by an otoscope. To address this shortcoming, optical coherence tomography (OCT) has been integrated into a handheld imaging probe. This system can non-invasively and quantitatively assess middle ear effusions and identify the presence of bacterial biofilms in the middle ear cavity during ear infections. Furthermore, the complete OCT system is housed in a standard briefcase to maximize its portability as a diagnostic device. Nonetheless, interpreting OCT images of the middle ear more often requires expertise in OCT as well as middle ear infections, making it difficult for an untrained user to operate the system as an accurate stand-alone diagnostic tool in clinical settings. Here, we present a briefcase OCT system implemented with a real-time machine learning platform for middle ear infections. A random forest-based classifier can categorize images based on the presence of middle ear effusions and biofilms. This study demonstrates that our briefcase OCT system coupled with machine learning can provide user-invariant classification results of middle ear conditions, which may greatly improve the utility of this technology for the diagnosis and management of middle ear infections.

Biofilm distribution on tympanostomy tubes: An ex vivo descriptive study

BACKGROUND

Tympanostomy tube (TT) insertion is a common procedure in children with otitis media with effusion. Post-TT otorrhea (PTTO) is a frequent post-operative complication. Biofilms are involved in chronic PTTO cases.

OBJECTIVE

To describe and qualitatively analyze the geometry and sites prone to biofilms on removed TTs, relatively to their position in the ear, past medical/surgical history and PTTO presence.

METHODS

Biofilms presence and topographic distribution on TTs were ex vivo evaluated by using scanning electron microscope, confocal microscope and stereo-microscope.

RESULTS

Forty-eight TTs from 30 children were analyzed. Indications for removal were: 71% due to retained TTs (average time from insertion: 24.4 ± 15.1 months), 23% due to chronic PTTO, and 6% due to TT obstruction/dysfunction. Different types of bacterial biofilms were detected on all TTs, regardless the time from their insertion nor their types. Biofilms were observed more on the perpendicular junction and on the internal lumen, and more biofilm colonies were detected on the medial part, facing the middle ear mucosa. TTs removed from children with PTTO exhibited more biofilm colonies when compared to their peers. Of the 16 children who underwent adenoidectomy concomitantly with TT insertion, 10 (62%) children were sent for TT removal due to retained TTs, and 6 (38%) children due to chronic PTTO (p = 0.03).

CONCLUSION

Descriptive analysis of biofilm topographic distribution demonstrated adhesions on specific TT areas: perpendicular junctions and the internal lumen. Such "prone zones" may be the future target areas for changes in TT geometry or can be specifically coated with anti-biofilm materials.

Otitis media with effusion is not a sterile inflammatory process: scanning electron microscope evidence

PURPOSE

We aimed to demonstrate whether chronic otitis media with effusion (OME) is a sterile condition or biofilms-related disease through direct visualization of middle ear mucosa by Scanning electron microscopy (SEM) and culture of the effusion.

METHODS

This case-control study included 60 children in two groups; the case group included 50 patients undergoing ventilation tube insertion (VTI) for Chronic OME (COME), and the control group included ten patients undergoing cochlear implantation (CI) surgery presenting normal middle ear mucosa. Biopsies from both groups' middle ear mucosa were evaluated for biofilm formation using scanning electron microscopy (SEM). Middle ear effusion (MEE) samples from COME patients were cultured on blood agar to detect and identify any bacterial growth. The adenoid size was evaluated and correlated to the biofilm formation in COME patients.

RESULTS

There was a significant difference between case and control groups regarding biofilm formation (p-value < 0.001*). Biofilm was evident in 84% of the COME patients (cases group) and absent in the control group. Only 12 COME patients (24%) had positive MEE culture, however, 76.2% of patients with biofilm had a negative culture. Streptococcus pneumonia was the most common otopathogen found either alone or combined with other otopathogens. There was a significant negative correlation between adenoid size and biofilm grade among the studied patients.

CONCLUSION

The visual identification of middle ear biofilms indicated their role in chronic OME. Middle ear biofilms need to be expected in children with OME, especially those who do not need adenoid surgery.

Peripheral blood immunological parameters of children with adenoid hypertrophy with otitis media with effusion: propensity score matching

PURPOSE

To evaluate peripheral blood immunological parameters and the possible correlation with age, gender and adenoid size in children with adenoid hypertrophy with OME.

METHODS

A total of 664 children with adenoid hypertrophy were initially enrolled in our study, of which 83 had concomitant OME. To minimize selection bias, we performed one to two propensity score matching (PSM) between children with and without OME. After PSM, 80 children with OME (OME group) and 157 children without OME (adenoid hypertrophy [AH] group) were selected. The patients' peripheral blood samples were prepared prior to surgery and their immunological parameters were compared between groups.

RESULTS

Compared to the AH group, the serum level of C3 was significantly higher in the OME group (0.88 ± 0.01 g/L vs. 0.94 ± 0.02 g/L; p = 0.014), which was the only independent risk factor for OME (odds ratio 13.58, 95% confidence interval 1.25-147.99; p = 0.032). However, no such difference was seen for serum immunoglobulin (IgG, IgA, IgM, IgE), T cell subsets (CD3+, CD4+ and CD8+ T cells), or lymphocytes and monocytes. Further subgroup analyses showed that in children ≤ 5 years old, the C3 level was significantly higher in OME patients (p = 0.023). A subgroup analysis based on sex indicated that there was a significantly higher level of serum C3 (p = 0.009) and lower CD3+ and CD4+ T cells (p = 0.010 and p = 0.021, respectively) in girls with OME compared to those without OME. No association between immunological parameters and adenoid size was found.

CONCLUSIONS

There were no significant differences in cellular immunology and humoral immune indicators in children with adenoid hypertrophy with or without OME. In children ≤ 5 years old, significantly higher serum C3 levels in patients with OME demonstrate excessively activated C3 in comparison to patients without OME. For girls, a higher serum level of C3 with a lower amount of CD3+ and CD4+ T cells may be associated with OME.

Role of Biofilms in Children with Chronic Adenoiditis and Middle Ear Disease

Chronic adenoiditis occurs frequently in children, and it is complicated by the subsequent development of recurrent or chronic middle ear diseases, such as recurrent acute otitis media, persistent otitis media with effusion and chronic otitis media, which may predispose a child to long-term functional sequalae and auditory impairment. Children with chronic adenoidal disease who fail to respond to traditional antibiotic therapy are usually candidates for surgery under general anaesthesia. It has been suggested that the ineffectiveness of antibiotic therapy in children with chronic adenoiditis is partially related to nasopharyngeal bacterial biofilms, which play a role in the development of chronic nasopharyngeal inflammation due to chronic adenoiditis, which is possibly associated with chronic or recurrent middle ear disease. This paper reviews the current evidence concerning the involvement of bacterial biofilms in the development of chronic adenoiditis and related middle ear infections in children.

Subversion of host immune responses by otopathogens during otitis media

Otitis media (OM) is one of the most common ear diseases affecting humans. Children are at greater risk and suffer most frequently from OM, which can cause serious deterioration in the quality of life. OM is generally classified into two main types: acute and chronic OM (AOM and COM). AOM is characterized by tympanic membrane swelling or otorrhea and is accompanied by signs or symptoms of ear infection. In COM, there is a tympanic membrane perforation and purulent discharge. The most common pathogens that cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis whereas Pseudomonas aeruginosa and Staphylococcus aureus are commonly associated with COM. Innate and adaptive immune responses provide protection against OM. However, pathogens employ a wide arsenal of weapons to evade potent immune responses and these mechanisms likely contribute to AOM and COM. Immunologic evasion is multifactorial, and involves damage to host mucociliary tract, genetic polymorphisms within otopathogens, the number and variety of different otopathogens in the nasopharynx as well as the interaction between the host's innate and adaptive immune responses. Otopathogens utilize host mucin production, phase variation, biofilm production, glycans, as well as neutrophil and eosinophilic extracellular traps to induce OM. The objective of this review article is to discuss our current understanding about the mechanisms through which otopathogens escape host immunity to induce OM. A better knowledge about the molecular mechanisms leading to subversion of host immune responses will provide novel clues to develop effective treatment modalities for OM.

Mesoporous Silica Materials as Drug Delivery: "The Nightmare" of Bacterial Infection

Mesoporous silica materials (MSM) have a great surface area and a high pore volume, meaning that they consequently have a large loading capacity, and have been demonstrated to be unique candidates for the treatment of different pathologies, including bacterial infection. In this text, we review the multiple ways of action in which MSM can be used to fight bacterial infection, including early detection, drug release, targeting bacteria or biofilm, antifouling surfaces, and adjuvant capacity. This review focus mainly on those that act as a drug delivery system, and therefore that have an essential characteristic, which is their great loading capacity. Since MSM have advantages in all stages of combatting bacterial infection; its prevention, detection and finally in its treatment, we can venture to talk about them as the "nightmare of bacteria".

Microbial otitis media: recent advancements in treatment, current challenges and opportunities

Otitis media (OM) is a common disease affecting humans, especially paediatric populations. OM refers to inflammation of the middle ear and can be broadly classified into two types, acute and chronic. Bacterial infection is one of the most common causes of OM. Despite the introduction of vaccines, the incidence of OM remains significantly high worldwide. In this mini-review article, we discuss the recent treatment modalities for OM, such as suspension gel, transcutaneous immunization, and intranasal and transtympanic drug delivery, including therapies that are currently undergoing clinical trials. We provide an overview of how these recent advancements in therapeutic strategies can facilitate the circumvention of current treatment challenges involving preadolescence soft palate dysfunction, biofilm formation, tympanic membrane (ear drum) barrier and the attainment of efficacious drug concentrations in the middle ear. While traditional first-line immunization strategies are generally not very efficacious against biofilms, new technologies that use transdermal or intranasal drug delivery via chitosan-PsaA nanoparticles have shown promising results in experimental animal models of OM. Sustained drug delivery systems such as penta-block copolymer poloxamer 407-polybutylphosphoester (P407-PBP) or poloxamer 407 (e.g. OTO-201, with the brand name 'OTIPRIO') have demonstrated that treatments can be reduced to a single topical application. The emergence of effective new treatment modalities opens up promising new avenues for the treatment of OM that could lead to improved quality of life for many children and their families.

Interaction Between Allergy and Middle Ear Infection

PURPOSE OF REVIEW

Recent studies have attempted to identify interactions among the causes of otitis media with effusion (OME). This review discusses the interaction between allergy and infection with regard to host and environmental factors in terms of the development of OME.

RECENT FINDINGS

Protection of the upper airway against microbial invasion requires active interaction between the defense mechanisms of the respiratory epithelium, including innate and adaptive immunity, and mechanical factors. The impairment of these defenses due to allergy and/or increased bacterial resistance may lead to increased susceptibility to infectious organisms in the respiratory tract and middle ear mucosa. Recent genetic studies have provided valuable information about the association of Toll-like receptor signaling variations with clinical phenotypes and the risk of infection in the middle ear. Among the causal factors of OME, allergy not only induces an inflammatory reaction in the middle ear cavity but also facilitates the invasion of infectious pathogens. There is also evidence that allergy can affect the susceptibility of patients to infection of the upper respiratory tract, including the middle ear cavity.