The Role of Biofilms in Chronic Otitis Media-Active Squamosal Disease: An Evaluative Study

Pharmacological strategies for targeting biofilms in otorhinolaryngologic infections and overcoming antimicrobial resistance (Review)

Biofilm formation is a key factor in the persistence and recurrence of otorhinolaryngology (ORL) infections, driving antimicrobial resistance and treatment failure. Chronic conditions, such as rhinosinusitis, otitis media and tonsillitis, are linked to biofilm-producing pathogens, forming protective extracellular matrices that shield bacteria from immune defenses and antibiotics. The present review explores emerging pharmacological strategies to disrupt biofilm integrity and improve treatment outcomes. Strategies such as quorum sensing inhibitors, antibiofilm peptides, enzymatic dispersal agents, and drug repurposing can potentially disrupt biofilms and counter-resistance mechanisms. Furthermore, novel therapies (including nanotechnology-based drug delivery systems, phage therapy and immunomodulation) offer innovative alternatives for managing biofilm-associated infections. However, clinical implementation remains challenging. Future research should prioritize optimizing drug formulations, refining delivery techniques, and exploring synergistic combinations to enhance biofilm eradication. Implementing these innovative strategies can improve the management of chronic ORL infections, reducing recurrence rates and enhancing patient outcomes.

Chronic suppurative otitis media

Chronic suppurative otitis media (CSOM) is a leading global cause of potentially preventable hearing loss in children and adults, associated with socioeconomic deprivation. There is an absence of consensus on the definition of CSOM, which complicates efforts for prevention, treatment, and monitoring. CSOM occurs when perforation of the tympanic membrane is associated with severe or persistent inflammation in the middle ear, leading to hearing loss and recurrent or persistent ear discharge (otorrhoea). Cholesteatoma, caused by the inward growth of the squamous epithelium of the tympanic membrane into the middle ear, can also occur. The optimal treatment of discharge in CSOM is topical antibiotics. In resource-limited settings where topical antibiotics might not be available, topical antiseptics are an alternative. For persistent disease, surgery to repair the tympanic membrane or remove cholesteatoma might offer long-term resolution of otorrhoea and potential improvement to hearing. Recent developments in self-fitted air-conduction and bone-conduction hearing aids offer promise as new options for rehabilitation.

In Vitro Antibiofilm Effect of N-Acetyl-L-cysteine/Dry Propolis Extract Combination on Bacterial Pathogens Isolated from Upper Respiratory Tract Infections

Bacterial biofilms play an important role in the pathogenesis of chronic upper respiratory tract infections. In addition to conventional antimicrobial therapy, N-acetyl-L-cysteine (NAC) and propolis are dietary supplements that are often recommended as supportive therapy for upper respiratory tract infections. However, no data on the beneficial effect of their combination against bacterial biofilms can be found in the scientific literature. Therefore, the aim of our study was to investigate the in vitro effect of N-acetyl-L-cysteine (NAC) and dry propolis extract in fixed combinations (NAC/dry propolis extract fixed combination) on biofilm formation by bacterial species isolated from patients with chronic rhinosinusitis, chronic otitis media, and chronic adenoiditis. The prospective study included 48 adults with chronic rhinosinusitis, 29 adults with chronic otitis media, and 33 children with chronic adenoiditis. Bacteria were isolated from tissue samples obtained intraoperatively and identified using the MALDI-TOF Vitek MS System. The antimicrobial activity, synergism, and antibiofilm effect of NAC/dry propolis extract fixed combination were studied in vitro. A total of 116 different strains were isolated from the tissue samples, with staphylococci being the most frequently isolated in all patients (57.8%). MICs of the NAC/dry propolis extract fixed combination ranged from 1.25/0.125 to 20/2 mg NAC/mg propolis. A synergistic effect (FICI ≤ 0.5) was observed in 51.7% of strains. The majority of isolates from patients with chronic otitis media were moderate biofilm producers and in chronic adenoiditis they were weak biofilm producers, while the same number of isolates in patients with chronic rhinosinusitis were weak and moderate biofilm producers. Subinhibitory concentrations of the NAC/propolis combination ranging from 0.625-0.156 mg/mL to 10-2.5 mg/mL of NAC combined with 0.062-0.016 mg/mL to 1-0.25 mg/mL of propolis inhibited biofilm formation in all bacterial strains. Suprainhibitory concentrations ranging from 2.5-10 mg/mL to 40-160 mg/mL of NAC in combination with 0.25-1 mg/mL to 4-16 mg/mL of propolis completely eradicated the biofilm. In conclusion, the fixed combination of NAC and dry propolis extract has a synergistic effect on all stages of biofilm formation and eradication of the formed biofilm in bacteria isolated from upper respiratory tract infections.

ISOM 2023 research Panel 4 - Diagnostics and microbiology of otitis media

OBJECTIVES

To identify and review key research advances from the literature published between 2019 and 2023 on the diagnosis and microbiology of otitis media (OM) including acute otitis media (AOM), recurrent AOM (rAOM), otitis media with effusion (OME), chronic suppurative otitis media (CSOM) and AOM complications (mastoiditis).

DATA SOURCES

PubMed database of the National Library of Medicine.

REVIEW METHODS

All relevant original articles published in Medline in English between July 2019 and February 2023 were identified. Studies that were reviews, case studies, relating to OM complications (other than mastoiditis), and studies focusing on guideline adherence, and consensus statements were excluded. Members of the panel drafted the report based on these search results.

MAIN FINDINGS

For the diagnosis section, 2294 unique records screened, 55 were eligible for inclusion. For the microbiology section 705 unique records were screened and 137 articles were eligible for inclusion. The main themes that arose in OM diagnosis were the need to incorporate multiple modalities including video-otoscopy, tympanometry, telemedicine and artificial intelligence for accurate diagnoses in all diagnostic settings. Further to this, was the use of new, cheap, readily available tools which may improve access in rural and lowmiddle income (LMIC) settings. For OM aetiology, PCR remains the most sensitive method for detecting middle ear pathogens with microbiome analysis still largely restricted to research use. The global pandemic response reduced rates of OM in children, but post-pandemic shifts should be monitored.

IMPLICATION FOR PRACTICE AND FUTURE RESEARCH

Cheap, easy to use multi-technique assessments combined with artificial intelligence and/or telemedicine should be integrated into future practice to improve diagnosis and treatment pathways in OM diagnosis. Longitudinal studies investigating the in-vivo process of OM development, timings and in-depth interactions between the triad of bacteria, viruses and the host immune response are still required. Standardized methods of collection and analysis for microbiome studies to enable inter-study comparisons are required. There is a need to target underlying biofilms if going to effectively prevent rAOM and OME and possibly enhance ventilation tube retention.

Pathophysiological Link Between Chronic Rhinosinusitis and Ear Disease

PURPOSE OF REVIEW

In the clinical practice, patients affected by chronic rhinosinusitis (CRS) commonly complain of otologic symptoms. This review aims to describe the available literature evidence assessing the relationship between CRS and ear illnesses published in the last 5 years.

RECENT FINDINGS

Available evidence suggests a higher prevalence of otologic symptoms in patients suffering from CRS, affecting up to 87% of patients. These symptoms may be related to Eustachian tube dysfunction, which improves after treatment for CRS. A few studies suggested a potential but not confirmed role of CRS in cholesteatoma, chronic otitis media, and sensorineural hypoacusis. A special type of otitis media with effusion (OME) may occur in patients with CRS, which seems to respond well to new biologic therapy. Ear symptoms appear to be highly prevalent in patients with CRS. So far, the available evidence is robust only for Eustachian tube dysfunction, which has been shown to be particularly impaired in CRS patients. Additionally, the Eustachian tube function appears to improve after treatment for CRS. Finally, interesting preliminary data were described for eosinophilic otitis media, as it appears to respond well to the treatment with biologics.

Mapping of audiometric analysis with microbiological findings in patients with chronic suppurative otitis media (CSOM): a neglected clinical manifestation

Otitis media (OM) is an umbrella term for a number of conditions associated with middle ear inflammation. Chronic suppurative otitis media (CSOM), a type of OM, is characterized by long-term middle ear infection with perforated ear drum and otorrhea. The most common outcome associated with it is acquired hearing impairment in infected individuals which ultimately affects their cognitive and scholastic developments. Clinically, CSOM is thought to be a sequel of re-occurring episodes of Acute otitis media (AOM). Pseudomonas aeruginosa and Staphylococcus aureus are found to be the predominant pathogenic isolates in these patients. However, with the emergence of antibiotic resistance amongst these pathogens, the adequate evaluation and treatment of this condition has become more problematic. The disease has also been recognized as one of the neglected tropical clinical manifestations with high prevalence in school-age children, especially in poor or underprivileged countries. Moreover, untreated cases have further worsened the situation by contributing to various life-threatening complications. Thus, effective treatment and surgical strategies, as well as strengthening of hearing care algorithms along with the discovery of novel animal models for advanced clinical research, can jointly help to fight this disease. In this regard, mapping of the audiological analysis with microbiological findings in CSOM patients may help elucidate the frequency that favors growth of specific pathogens. Knowledge about this potential correlation can then support timely detection of the infection, which is perceived as one of the emerging approaches for its management. In addition to these strategies, creating a true sense of awareness among people can also help mitigate this pathological condition by facilitating early identification, prevention, and treatment. This review discusses the incidence, pathogenesis, investigations, complications, and available treatment modalities associated with CSOM.