Inflammation in the middle ear of children with recurrent or chronic otitis media is associated with bacterial load

17β-estradiol Attenuates the Middle Ear Inflammatory Response to Nontypeable Haemophilus influenzae

OBJECTIVES

17β-estradiol (E2) is a steroidal hormone with immunomodulatory functions that play a role in infectious and inflammatory diseases. E2 was recently identified as the leading upstream regulator of differentially expressed genes in a comparative RNA sequencing study of pediatric patients with otitis media (OM) versus OM-free counterparts and may therefore play a role in the inflammatory response to bacterial otopathogens during pediatric OM. This study examined the effect of E2 on bacterial-induced inflammatory cytokine expression in an in vitro pediatric OM model.

METHODS

An immortalized middle ear (ME) epithelial cell line, ROM-SV40, was developed from a pediatric recurrent OM patient. The culture was exposed to E2 at physiological levels for 1-48 h prior to 6 h-stimulation with nontypeable Haemophilus influenzae (NTHi) whole cell lysate. TNFA, IL1B, IL6, and IL8 were assayed by qPCR and ELISA.

RESULTS

E2 pretreatment (24 h) abrogated NTHi induction of IL6; a longer pretreatment (1-10 nM, 48 h) abrogated IL1B induction (p < 0.05). E2 pretreatment (5 nM, 48 h) abrogated NTHi-induced IL8 secretion (p = 0.017).

CONCLUSION

E2 pretreatment partially rescued NTHi-induced cytokine production by ME epithelia. These data support a role for E2 in moderating the excessive inflammatory response to middle ear infection that contributes to OM pathophysiology.

LEVELS OF EVIDENCE

NA Laryngoscope, 134:3815-3819, 2024.

Otitis Media Practice During the COVID-19 Pandemic

The global coronavirus disease-2019 (COVID-19) pandemic has changed the prevalence and management of many pediatric infectious diseases, including acute otitis media (AOM). Coronaviruses are a group of RNA viruses that cause respiratory tract infections in humans. Before the COVID-19 pandemic, coronavirus serotypes OC43, 229E, HKU1, and NL63 were infrequently detected in middle ear fluid (MEF) specimens and nasopharyngeal aspirates in children with AOM during the 1990s and 2000s and were associated with a mild course of the disease. At times when CoV was detected in OM cases, the overall viral load was relatively low. The new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen responsible for the eruption of the COVID-19 global pandemic. Following the pandemic declaration in many countries and by the World Health Organization in March 2020, preventive proactive measures were imposed to limit COVID-19. These included social distancing; lockdowns; closure of workplaces; kindergartens and schools; increased hygiene; use of antiseptics and alcohol-based gels; frequent temperature measurements and wearing masks. These measures were not the only ones taken, as hospitals and clinics tried to minimize treating non-urgent medical referrals such as OM, and elective surgical procedures were canceled, such as ventilating tube insertion (VTI). These changes and regulations altered the way OM is practiced during the COVID-19 pandemic. Advents in technology allowed a vast use of telemedicine technologies for OM, however, the accuracy of AOM diagnosis in those encounters was in doubt, and antibiotic prescription rates were still reported to be high. There was an overall decrease in AOM episodes and admissions rates and with high spontaneous resolution rates of MEF in children, and a reduction in VTI surgeries. Despite an initial fear regarding viral shedding during myringotomy, the procedure was shown to be safe. Special draping techniques for otologic surgery were suggested. Other aspects of OM practice included the presentation of adult patients with AOM who tested positive for SARS-2-CoV and its detection in MEF samples in living patients and in the mucosa of the middle ear and mastoid in post-mortem specimens.

Dysregulation of immune response in otitis media

Objective

Otitis media (OM) is a common reason for children to be prescribed antibiotics and undergo surgery but a thorough understanding of disease mechanisms is lacking. We evaluate the evidence of a dysregulated immune response in the pathogenesis of OM.

Methods

A comprehensive systematic review of the literature using search terms [otitis media OR glue ear OR AOM OR OME] OR [middle ear AND (infection OR inflammation)] which were run through Medline and Embase via Ovid, including both human and animal studies. In total, 82 955 studies underwent automated filtering followed by manual screening. One hundred studies were included in the review.

Results

Most studies were based on in vitro or animal work. Abnormalities in pathogen detection pathways, such as Toll-like receptors, have confirmed roles in OM. The aetiology of OM, its chronic subgroups (chronic OM, persistent OM with effusion) and recurrent acute OM is complex; however, inflammatory signalling mechanisms are frequently implicated. Host epithelium likely plays a crucial role, but the characterisation of human middle ear tissue lags behind that of other anatomical subsites.

Conclusions

Translational research for OM presently falls far behind its clinical importance. This has likely hindered the development of new diagnostic and treatment modalities. Further work is urgently required; particularly to disentangle the respective immune pathologies in the clinically observed phenotypes and thereby work towards more personalised treatments.

Correlation of pathogenic effects of laryngopharyngeal reflux and bacterial infection in COME of children

BACKGROUND

Bacteria infection and laryngopharyngeal reflux (LPR) were believed the important pathogenesis of chronic otitis media with effusion (COME). But no study researched the relationship between them on COME.

AIMS

To confirm bacterial could arrive middle ear through LPR and produced acid metabolites to activate the pepsinogen of LPR causing COME.

MATERIAL AND METHODS

Children (65) diagnosed COME with 122 middle ear effusions were included in COME group. Children (22) with congenital/acquired profound deafness with 22 middle ear lavage were included in CI group. Pepsin A concentration in the effusion and lavage fluid were measured. The DNA of the bacteria, IL-8 and TNF-α in the effusion were detected.

RESULTS

The average concentration of pepsin A in the effusions and lavage were 176.65 ± 242.09 and 19 ng/ml. Bacterial infection rates were 75.76% and 24.24% in the pepsin A(+) and pepsin A(-) patients. In the bacterial (+), the patients of pepsin A(+) was 4.33 times higher than those of pepsin A(-). TNF-α in pepsin A(+) was higher than that in pepsin A(-). TNF-α and IL-8 were higher in bacteria(+) than those of bacteria(-).

CONCLUSIONS

Bacterial infection and LPR might act in synergy in the pathogenesis of COME.

SIGNIFICANCE

First time to propose LPR and bacterial infection might work synergistically to cause COME.

Middle Ear Viral Load Considerations in the COVID-19 Era: A Systematic Review

OBJECTIVE

To systematically review the available medical literature to investigate the viral load in the middle ear and mastoid cavity and the potential risk of exposure to airborne viruses during otologic surgery.

DATA SOURCES

PubMed, MEDLINE, and Cochrane databases.

STUDY SELECTION

This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Protocol.

DATA EXTRACTION

Using the Boolean method and relevant search term combinations for terms "mastoid," "middle ear," "virus," "exposure" "COVID-19" "SARS-CoV-2." PubMed, MEDLINE, and Cochrane databases were queried. A total of 57 abstracts were identified and screened by two independent reviewers. Following inclusion and exclusion criteria, 18 studies were selected for the final analysis.

DATA SYNTHESIS

Due to the heterogeneity of clinical data, a meta-analysis was not feasible.

RESULTS

Rhinovirus, followed by respiratory syncytial virus are reported to be the most prevalent viruses in MEF samples but formal statistical analysis is precluded by the heterogeneity of the studies. Drilling was identified to have the highest risk for aerosol generation and therefore viral exposure during otologic Surgery.

CONCLUSIONS

The medical literature has consistently demonstrated the presence of nucleic acids of respiratory viruses involving the middle ear, including SARS-CoV2 in a recent postmortem study. Although no in vivo studies have been conducted, due to the likely risk of transmission, middle ear and mastoid procedures, particularly involving the use of a drill should be deferred, if possible, during the pandemic and enhanced personal protective equipment (PPE) used if surgery is necessary.

Fisetin administration improves LPS-induced acute otitis media in mouse in vivo

Acute otitis media is one of the most common infectious diseases worldwide in spite of the widespread vaccination. The present study was conducted to explore the effects of fisetin on mouse acute otitis media models. The animal models were established by lipopolysaccharide (LPS) injection into the middle ear of mice via the tympanic membrane. Fisetin was administered to mice for ten days through intragastric administration immediate after LPS application. Hematoxylin and eosin (H&E) staining was performed and the pro-inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 and VEGF, were measured through enzyme-linked immunosorbent assay (ELISA) method and RT-qPCR analysis. Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway was detected by immunoblotting assays. Reactive oxygen species (ROS) generated levels were determined through assessment of anti-oxidants, and TXNIP/MAPKs signaling pathways were explored to reveal the possible molecular mechanism for acute otitis media progression and the function of fisetin. Fisetin reduced mucosal thickness caused by LPS. In fisetin-treated animals, pro-inflammatory cytokine release was downregulated accompanied with TLR4/NF-κB inactivation. ROS production was significantly decreased in comparison to the LPS-treated group. The TXNIP/MAPKs signaling pathway was inactivated for fisetin treatment in LPS-induced mice with acute otitis media. The above results indicated that fisetin improved acute otitis media through inflammation and ROS suppression via inactivating TLR4/NF-κB and TXNIP/MAPKs signaling pathways.

Panel 1: Epidemiology and Diagnosis

Objective

To create a literature review between 2011 and June 1, 2015, on advances in otitis media (OM) epidemiology and diagnosis (including relevant audiology studies).

Data Sources

Electronic search engines (PubMed, EMBASE, and Cochrane Library) with a predefined search strategy.

Review Methods

Articles with appropriate epidemiologic methodology for OM, including acute mastoiditis and eustachian tube dysfunction. Items included OM worldwide and in high-risk populations, OM-related hearing loss, news in OM diagnostics, prenatal risk factors and comorbidities, postnatal risk factors, genetics, microbiological epidemiology, guidelines, and quality of life.

Conclusions

Diagnostic evidence and genetic studies are increasing; guidelines are introduced worldwide; and there is evidence of benefit of pneumococcal conjugate vaccines. New risk factors and comordities are identified in the study period, and quality of life is affected in children and their families.

Implications for Practice

Chronic suppurative OM occurs worldwide and contributes to lifelong hearing loss. Uniform definitions are still lacking and should be provided. An association between HIV and chronic suppurative OM has been found. Tympanometry is recommended for diagnosis, with or without pneumatic otoscopy. Video otoscopy, algorithms, and validated questionnaires may assist clinicians. Childhood obesity is associated with OM. Heritability accounts for 20% to 50% of OM diagnoses. OM-prone children seem to produce weaker immunologic responses to pneumococcal conjugate vaccines. Clinicians tend to individualize treatment without adhering to guidelines.

Panel 5: Immunology

Objective

To perform a state-of-the-art review of the literature from January 2012 through May 2015 on studies that advanced our knowledge of the innate and adaptive immunology related to otitis media. This review also proposes future directions for research in this area.

Data Sources

PubMed database of the National Library of Medicine.

Review Methods

Three subpanels comprising experts in the field focused on sections relevant to cytokines, innate immunity, and adaptive immunity. The review focused on animal, cell line, and human studies and was critical in relation to the recommendations from the previous publication and for determination of the proposed goals and priorities. The panel met at the 18th International Symposium on Recent Advances in Otitis Media in June 2015 to consolidate its prior search results and discuss, plan, and refine the review. The panel approved the final draft.

Conclusion

From 2012 to 2014, tremendous progresses in immunology of otitis media were established—especially in the areas of innate immunity associated with the pathogenesis of otitis media.

Implications for Practice

The advances of the past 4 years formed the basis for a series of short- and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media, especially for recurrent otitis media.

Population density profiles of nasopharyngeal carriage of 5 bacterial species in pre-school children measured using quantitative PCR offer potential insights into the dynamics of transmission

Bacterial vaccines can reduce carriage rates. Colonization is usually a binary endpoint. Real time quantitative PCR (qPCR) can quantify bacterial DNA in mucosal samples over a wide range. Using culture and single-gene species-specific qPCRs for Streptococcus pneumoniae (lytA), Streptococcus pyogenes (ntpC), Moraxella catarrhalis (ompJ), Haemophilus influenzae (hdp) and Staphylococcus aureus (nuc) and standard curves against log-phase reference strain broth cultures we described frequency and peak density distributions of carriage in nasopharyngeal swabs from 161 healthy 2-4 y old children collected into STGG broth. In general, detection by qPCR and culture was consistent. Discordance mostly occurred at lower detection thresholds of both methods, although PCR assays for S. pyogenes and S. aureus were less sensitive. Density varied across 5-7 orders of magnitude for the 5 species with the abundant species skewed toward high values (modes: S. pneumoniae log3-4, M. catarrhalis & H. influenzae log4-5 CFU/ml broth). Wide ranges of bacterial DNA concentrations in healthy children carrying these bacteria could mean that different individuals at different times vary greatly in infectiousness. Understanding the host, microbial and environmental determinants of colonization density will permit more accurate prediction of vaccine effectiveness.

Evaluation of the Interleukin-1 Receptor Antagonist and Immunoregulatory Interleukin-10 in the Middle Ear in Chronic Otitis Media With Effusion in Children With and Without Atopy

Objectives

The role of pro-inflammatory cytokines in the course of chronic otitis media with effusion (COME) has been documented. However, there are fewer studies on the action of anti-inflammatory cytokines in the middle ear. We sought determine whether there is an association between COME and anti-inflammatory cytokines and whether there are any differences in the cytokine profile in COME children with and without atopy.

Methods

Eighty-four children were divided into 3 groups: 32 nonatopic children with COME (group NA), 31 atopic children with COME (group A), and 21 children without COME and without atopy (control group C). Specimens from the middle ear were collected and evaluated by enzyme-linked immunosorbent assay for the cytokines interleukin-1 receptor antagonist (IL-1Ra) and immunoregulatory IL-10.

Results

Significantly higher IL-10 concentrations were found in both nonatopic and atopic children with COME compared to controls. No significant differences in IL-1Ra levels were found between atopic and nonatopic children with COME and the control group.

Conclusion

We found no differences in the levels of IL-1Ra in atopic and nonatopic children with COME compared to controls. However, we found elevated IL-10 levels in the middle ear effusions from children with COME, with or without atopy. These elevated immunoregulatory cytokine levels suggest a role for new immunomodulatory treatments to prevent disease progression in COME, regardless of atopy.

Comparative Genomic Analyses of the Moraxella catarrhalis Serosensitive and Seroresistant Lineages Demonstrate Their Independent Evolution

The bacterial speciesMoraxella catarrhalishas been hypothesized as being composed of two distinct lineages (referred to as the seroresistant [SR] and serosensitive [SS]) with separate evolutionary histories based on several molecular typing methods, whereas 16S ribotyping has suggested an additional split within the SS lineage. Previously, we characterized whole-genome sequences of 12 SR-lineage isolates, which revealed a relatively small supragenome when compared with other opportunistic nasopharyngeal pathogens, suggestive of a relatively short evolutionary history. Here, we performed whole-genome sequencing on 18 strains from both ribotypes of the SS lineage, an additional SR strain, as well as four previously identified highly divergent strains based on multilocus sequence typing analyses. All 35 strains were subjected to a battery of comparative genomic analyses which clearly show that there are three lineages-the SR, SS, and the divergent. The SR and SS lineages are closely related, but distinct from each other based on three different methods of comparison: Allelic differences observed among core genes; possession of lineage-specific sets of core and distributed genes; and by an alignment of concatenated core sequences irrespective of gene annotation. All these methods show that the SS lineage has much longer interstrain branches than the SR lineage indicating that this lineage has likely been evolving either longer or faster than the SR lineage. There is evidence of extensive horizontal gene transfer (HGT) within both of these lineages, and to a lesser degree between them. In particular, we identified very high rates of HGT between these two lineages for ß-lactamase genes. The four divergent strains aresui generis, being much more distantly related to both the SR and SS groups than these other two groups are to each other. Based on average nucleotide identities, gene content, GC content, and genome size, this group could be considered as a separate taxonomic group. The SR and SS lineages, although distinct, clearly form a single species based on multiple criteria including a large common core genome, average nucleotide identity values, GC content, and genome size. Although neither of these lineages arose from within the other based on phylogenetic analyses, the question of how and when these lineages split and then subsequently reunited in the human nasopharynx is explored.

Ability of Antibiotic-Resistant Nonvaccine-Type Pneumococcal Clones to Cause Otitis Media in an Infant Mouse Model of Pneumococcal-Influenza Virus Coinfection

The introduction of the 7-valent pneumococcal conjugate vaccine in Portugal resulted in reduced carriage in children by vaccine-type strains and an increased carriage of three major antibiotic-resistant clones, ST2191, ST276, and ST63 expressing capsules 6A, 19A, and 15A, respectively. Pneumococcal otitis media (OM), a frequent infection among preschool age children, is often associated with viral coinfection. To evaluate the ability of these three antibiotic-resistant clones to cause disease, we used an infant mouse model of influenza virus pneumococcal coinfection. The 6A and 19A clonal types induced OM, while 15A induced pneumococcal pneumonia and bloodstream infection, suggesting potential for invasive disease.

Live attenuated influenza virus increases pneumococcal translocation and persistence within the middle ear

BACKGROUND

Infection with influenza A virus (IAV) increases susceptibility to respiratory bacterial infections, resulting in increased bacterial carriage and complications such acute otitis media, pneumonia, bacteremia, and meningitis. Recently, vaccination with live attenuated influenza virus (LAIV) was reported to enhance subclinical bacterial colonization within the nasopharynx, similar to IAV. Although LAIV does not predispose to bacterial pneumonia, whether it may alter bacterial transmigration toward the middle ear, where it could have clinically relevant implications, has not been investigated.

METHODS

BALB/c mice received LAIV or phosphate-buffered saline 1 or 7 days before or during pneumococcal colonization with either of 2 clinical isolates, 19F or 7F. Middle ear bacterial titers were monitored daily via in vivo imaging.

RESULTS

LAIV increased bacterial transmigration to and persistence within the middle ear. When colonization followed LAIV inoculation, a minimum LAIV incubation period of 4 days was required before bacterial transmigration commenced.

CONCLUSIONS

While LAIV vaccination is safe and effective at reducing IAV and coinfection with influenza virus and bacteria, LAIV may increase bacterial transmigration to the middle ear and could thus increase the risk of clinically relevant acute otitis media. These data warrant further investigations into interactions between live attenuated viruses and naturally colonizing bacterial pathogens.

Cytokine, chemokine, and Toll-like receptor expression in middle ear fluids of children with acute otitis media

OBJECTIVES/HYPOTHESIS

Acute otitis media (AOM) is a common bacterial infection in childhood that causes an inflammatory response in the middle ear. Leukocytes produce different inflammatory molecules in vitro when stimulated with Gram-positive and Gram-negative bacteria. The major causes of AOM are Streptococcus pneumoniae, nontypeable Haemophilus influenza, and Moraxella catarrhalis. We sought to assess differences in cytokines, chemokines, and expression of Toll-like receptors (TLRs) at onset of AOM based on bacterial culture results.

STUDY DESIGN

Middle ear fluid (MEF) from 66 children with AOM was studied.

METHODS

Innate immune genes, cytokines (interleukin [IL]-6, IL-8, IL-10, IL1-β; tumor necrosis factor-α), chemokines (CCL2, CCL3, CCL4, CCR5, CXCR3), and Toll-like receptors (TLR2, TLR4, TLR9) expression was measured using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) from MEF collected in vivo by tympanocentesis.

RESULTS

Culture-positive MEF had higher levels of all cytokines and chemokines (9-300-fold) as compared to MEF that was culture negative. Polymerase chain reaction (PCR)-positive/culture-negative MEF for otopathogens showed significant differences (P < .01) in TLR2, TLR4, and TLR9 expression (6-31-fold), but cytokine and chemokine levels were similar compared to PCR-negative/culture-negative MEF. No significant differences were found in the cytokine/chemokine/TLR levels among the bacterial otopathogen species. However, higher levels of TLRs, and all the cytokine and chemokines were detected when more than one bacterial species was present compared to single otopathogens.

CONCLUSIONS

Expression levels of proinflammatory cytokines/chemokines and TLRs are elevated in AOM children with a bacterial otopathogen, and are dependent on the number of bacterial species identified.

Live attenuated influenza vaccine enhances colonization of Streptococcus pneumoniae and Staphylococcus aureus in mice

Community interactions at mucosal surfaces between viruses, like influenza virus, and respiratory bacterial pathogens are important contributors toward pathogenesis of bacterial disease. What has not been considered is the natural extension of these interactions to live attenuated immunizations, and in particular, live attenuated influenza vaccines (LAIVs). Using a mouse-adapted LAIV against influenza A (H3N2) virus carrying the same mutations as the human FluMist vaccine, we find that LAIV vaccination reverses normal bacterial clearance from the nasopharynx and significantly increases bacterial carriage densities of the clinically important bacterial pathogens Streptococcus pneumoniae (serotypes 19F and 7F) and Staphylococcus aureus (strains Newman and Wright) within the upper respiratory tract of mice. Vaccination with LAIV also resulted in 2- to 5-fold increases in mean durations of bacterial carriage. Furthermore, we show that the increases in carriage density and duration were nearly identical in all aspects to changes in bacterial colonizing dynamics following infection with wild-type (WT) influenza virus. Importantly, LAIV, unlike WT influenza viruses, had no effect on severe bacterial disease or mortality within the lower respiratory tract. Our findings are, to the best of our knowledge, the first to demonstrate that vaccination with a live attenuated viral vaccine can directly modulate colonizing dynamics of important and unrelated human bacterial pathogens, and does so in a manner highly analogous to that seen following wild-type virus infection.

Following infection with an influenza virus, infected or recently recovered individuals become transiently susceptible to excess bacterial infections, particularly Streptococcus pneumoniae and Staphylococcus aureus. Indeed, in the absence of preexisting comorbidities, bacterial infections are a leading cause of severe disease during influenza epidemics. While this synergy has been known and is well studied, what has not been explored is the natural extension of these interactions to live attenuated influenza vaccines (LAIVs). Here we show, in mice, that vaccination with LAIV primes the upper respiratory tract for increased bacterial growth and persistence of bacterial carriage, in a manner nearly identical to that seen following wild-type influenza virus infections. Importantly, LAIV, unlike wild-type virus, did not increase severe bacterial disease of the lower respiratory tract. These findings may have consequences for individual bacterial disease processes within the upper respiratory tract, as well as bacterial transmission dynamics within LAIV-vaccinated populations

Cytokine responses in the common cold and otitis media

Cytokines are a group of diverse molecules that influence the function of every organ system. They are most well studied in their effects on the immune system and their integral role in mediating inflammation. The common cold and otitis media are two such disease states, and much has been learned about the various effects of cytokines in each disease. Most often the viruses isolated include rhinovirus (RV), respiratory syncytial virus (RSV), adenovirus, coronavirus, and picornavirus. Otitis media, sinusitis, bronchiolitis, pneumonia, and asthma exacerbation are commonly accepted as complications of viral upper respiratory tract infections. Furthermore, otitis media and upper respiratory infections are inextricably linked in that the majority (>70 %) of cases of acute otitis media occur as complications of the common cold. Cytokine polymorphisms have been associated with the severity of colds as well as the frequency of otitis media. This article attempts to update the reader on various studies that have recently been published regarding the role of cytokines in these two disease entities.