Microbiology of acute otitis media in children with tympanostomy tubes: prevalences of bacteria and viruses

Incidence and Characteristics of Pediatric Patients with Acute Otitis Hospitalized in a Romanian Infectious Diseases Hospital

BACKGROUND

Otic involvement is common in children during acute infectious diseases, and is an important cause of morbidity and health service utilization.

METHODS

We performed a retrospective analysis of pediatric cases hospitalized in the largest infectious disease hospital in Romania between 2018 and 2023, with the aim of quantifying the incidence and impact of acute otitis (AO) according to pediatric age subgroups.

RESULTS

A total of 1118 cases diagnosed with AO were eligible and included in the analysis. Acute congestive otitis media was the most common subtype, identified in 53.3% of cases, followed by acute purulent otitis media (APOM) in 26.7% of children. The majority of AO cases (69.9%) were diagnosed in the pre-pandemic period (2018-2019), and infants (10.6%), toddlers (49.4%), and preschoolers (29.2%) were the most affected age groups. A viral infection associated with the AO episode was documented in 49.6% of cases. Influenza viruses were most commonly reported (20.5%), followed by SARS-CoV-2 (5.8%), and adenovirus (4.9%). A total of 38 cases of AO were identified in children with measles. In 15.9% of APOM cases, Streptococcus pneumoniae was isolated by culture from otic secretions. The duration of hospitalization was longer in children with APOM and acute otitis externa compared to the other subtypes of AO (p < 0.001).

CONCLUSIONS

Our study highlights the importance of ENT (ear, nose, and throat) monitoring in children hospitalized for acute infectious diseases, as the majority of AO cases occur in the context of a viral infection. These findings emphasize the necessity for tailored assessment and intervention in suspected cases of AO, especially in young children under 5 years of age.

Tympanostomy Tube Otorrhea: Microbiological Differences Between Children with and Without Cleft Palate

OBJECTIVE

To characterize and compare microbiological profiles in tympanostomy tube otorrhea for children with and without cleft palate.

DESIGN

Retrospective cohort study.

SETTING

Pediatric otolaryngology and multidisciplinary cleft/craniofacial clinic at a single tertiary care center.

PATIENTS

Children with and without cleft palate <18 years of age who underwent tympanostomy tube placement between 2017-2021.

MAIN OUTCOME MEASURES

Otopathogen profiles and antibiotic resistance patterns in ear culture specimens obtained in children presenting for treatment of recalcitrant post-tympanostomy tube otorrhea.

RESULTS

Of the 886 children with tympanostomy tubes placed between 2017-2021, 345 (38.9%) had clinically significant otorrhea defined as requiring at least one otolaryngology visit for treatment. Children with cleft palate had higher rates of otorrhea (50.0% versus 35.7%; P < .01). In the 128 cultures obtained, Staphylococcus aureus was the most common organism in both groups present in 39.8% of cultures; 49% were methicillin-resistant (MRSA). Pseudomonas aeruginosa was also frequently isolated (20.0% versus 23.4%, P = .69) in children with and without cleft palate. Collectively, fluoroquinolone resistance was observed in 68.6% and 27.6% of the S. aureus and P. aeruginosa isolates, respectively, however, no differences in fluoroquinolone resistance were observed between cleft and non-cleft cohorts. Corynebacterium species were isolated more frequently in children with cleft palate (26.7% versus 6.1%, P < .01), a finding of unclear significance.

CONCLUSIONS

Recalcitrant post-tympanostomy tube otorrhea is more common in children with cleft palate. MRSA was the most common isolate, which was commonly resistant to first-line fluoroquinolone therapy.

Proposed Quality Indicators for Aspects of Pediatric Acute Otitis Media Management

BACKGROUND

The high incidence of pediatric acute otitis media (AOM) makes the implications of overdiagnosis and overtreatment far-reaching. Quality indicators (QIs) for AOM are limited, drawing from generalized upper respiratory infection QIs, or locally developed benchmarks. Recognizing this, we sought to develop pediatric AOM QIs to build a foundation for future quality improvement efforts.

METHODS

Candidate indicators (CIs) were extracted from existing guidelines and position statements. The modified RAND Corporation/University of California, Los Angeles (RAND/UCLA) appropriateness methodology was used to select the final QIs by an 11-member expert panel consisting of otolaryngology-head and neck surgeons, a pediatrician and family physician.

RESULTS

Twenty-seven CIs were identified after literature review, with an additional CI developed by the expert panel. After the first round of evaluations, the panel agreed on 4 CIs as appropriate QIs. After an expert panel meeting and subsequent second round of evaluations, the panel agreed on 8 final QIs as appropriate measures of high-quality care. The 8 final QIs focus on topics of antimicrobial management, specialty referral, and tympanostomy tube counseling.

CONCLUSIONS

Evidence of variable and substandard care persists in the diagnosis and management of pediatric AOM despite the existence of high-quality guidelines. This study proposes 8 QIs which compliment guideline recommendations and are meant to facilitate future quality improvement initiatives that can improve patient outcomes.

A cooperativity between virus and bacteria during respiratory infections

Respiratory tract infections remain the leading cause of morbidity and mortality worldwide. The burden is further increased by polymicrobial infection or viral and bacterial co-infection, often exacerbating the existing condition. Way back in 1918, high morbidity due to secondary pneumonia caused by bacterial infection was known, and a similar phenomenon was observed during the recent COVID-19 pandemic in which secondary bacterial infection worsens the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) condition. It has been observed that viruses paved the way for subsequent bacterial infection; similarly, bacteria have also been found to aid in viral infection. Viruses elevate bacterial infection by impairing the host's immune response, disrupting epithelial barrier integrity, expression of surface receptors and adhesion proteins, direct binding of virus to bacteria, altering nutritional immunity, and effecting the bacterial biofilm. Similarly, the bacteria enhance viral infection by altering the host's immune response, up-regulation of adhesion proteins, and activation of viral proteins. During co-infection, respiratory bacterial and viral pathogens were found to adapt and co-exist in the airways of their survival and to benefit from each other, i.e., there is a cooperative existence between the two. This review comprehensively reviews the mechanisms involved in the synergistic/cooperativity relationship between viruses and bacteria and their interaction in clinically relevant respiratory infections.

Design of medical tympanostomy conduits with selective fluid transport properties

Implantable tubes, shunts, and other medical conduits are crucial for treating a wide range of conditions from ears and eyes to brain and liver but often impose serious risks of device infection, obstruction, migration, unreliable function, and tissue damage. Efforts to alleviate these complications remain at an impasse because of fundamentally conflicting design requirements: Millimeter-scale size is required to minimize invasiveness but exacerbates occlusion and malfunction. Here, we present a rational design strategy that reconciles these trade-offs in an implantable tube that is even smaller than the current standard of care. Using tympanostomy tubes (ear tubes) as an exemplary case, we developed an iterative screening algorithm and show how unique curved lumen geometries of the liquid-infused conduit can be designed to co-optimize drug delivery, effusion drainage, water resistance, and biocontamination/ingrowth prevention in a single subcapillary-length-scale device. Through extensive in vitro studies, we demonstrate that the engineered tubes enabled selective uni- and bidirectional fluid transport; nearly eliminated adhesion and growth of common pathogenic bacteria, blood, and cells; and prevented tissue ingrowth. The engineered tubes also enabled complete eardrum healing and hearing preservation and exhibited more efficient and rapid antibiotic delivery to the middle ear in healthy chinchillas compared with current tympanostomy tubes, without resulting in ototoxicity at up to 24 weeks. The design principle and optimization algorithm presented here may enable tubes to be customized for a wide range of patient needs.

Case-control study of relationship of infection by respiratory viruses with acute otitis media in Chinese children

Background

Acute otitis media (AOM) may occur as a complication of viral upper respiratory infection (URI) in children. Our objective was to examine children with URI + AOM or URI alone to determine the association of infection by different common respiratory viruses with AOM.

Methods

Nasopharyngeal swabs were collected from March 2014 to February 2015. Quantitative PCR was then used to identify the following 10 common respiratory viruses: respiratory syncytial virus (RSV); parainfluenza viruses 1-4 (PIVs); influenza virus type A (IFVA); influenza virus type B; human rhinovirus (HRV); enterovirus; human metapneumovirus; human coronavirus OC43, 229E, NL63, and HKU1; adenovirus; and human bocavirus.

Results

We examined 255 children with URIs (mean age: 32.9 ± 18.7 months), and 164 (64.1%) of them tested positive for at least one respiratory virus. The most common viruses were RSV (44, 24.3%), PIVs (28, 15.5%), and IFVA (25, 13.8%). Positivity for RSV was significantly greater in the URI + AOM group than in the URI group, but these groups did not differ in infection rates for the other 9 viruses. There were also significant seasonal differences in positivity for RSV, IFVA, HRV,HBoV, PIVs and EV.

Conclusion

Our results indicated a relationship between infection by common respiratory viruses and AOM in children from Beijing. A URI with RSV significantly increased the risk of AOM in these children.

A cascade nanozyme with antimicrobial effects against nontypeable Haemophilus influenzae

Otitis media (OM) is the main cause of pediatric antibiotic prescriptions. Nontypeable Haemophilus influenzae (NTHi) is a major OM pathogen, which forms a biofilm that resists conventional antimicrobials and immune clearance. Thus, novel treatments that are effective against NTHi and its biofilm are urgently required. Nanozymes (often inorganic nanoparticles) mimic natural enzymes' catalytic activities to generate strong antimicrobials at the site of infection, and thus represent one of the emerging solutions to the crisis of antimicrobial resistance. They mimic natural enzymes' activities, such as generating strong antimicrobials catalytically at the site of infection, to minimize overexposure. However, that in situ generation often relies on Reactive Oxygen Species (ROS) as precursors, a prerequisite that limits the broad deployment of nanozymes. To address this challenge, we designed a cascade nanozyme that generates an antiseptic, HOBr, from a ubiquitous non-ROS, i.e., O₂, which successfully eradicates NTHi. The cascade nanozyme simultaneously exhibits glucose oxidase (GOx)-like activity from gold nanoparticles (AuNPs) and haloperoxidase (HPO)-mimicking activity from vanadium pentoxide nanowires (V₂O₅ NWs) connected using dopamine (DPA). The cascade nanozyme demonstrated strong antimicrobial efficacy against NTHi and its biofilm, while showing improved biocompatibility compared to the nanozyme of V₂O₅ NWs alone. The cascade nanozyme thus points to a material-oriented infectious disease treatment strategy, where small-molecule antimicrobials are generated in real time at the site of infection for the benefit of autonomous dosing. This strategy potentially mitigates the development of antimicrobial resistance and reduces side effects.

Surfactant proteins and innate immunity of otitis media

Otitis media (OM) is the most common disease among young children and one of the most frequent reasons to visit the pediatrician. Development of OM requires nasopharyngeal colonization by a pathogen which must gain access to the tympanic cavity through the eustachian tube (ET) along with being able to overcome the defense mechanisms of the immune system and middle ear mucosa. OM can be caused by viral or bacterial infection. The three main bacterial pathogens are Streptococcus pneumoniae, nontypeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis. Innate immunity is important in OM resolution as the disease occurs in very young children before the development of specific immunity. Elements of innate immunity include natural barriers and pattern recognition receptors such as Toll like receptors (TLRs), and Nod like receptors (NLRs). Surfactant proteins A (SP-A) and D (SP-D) act as pattern recognition receptors and are found in the lung and many other tissues including the ET and the middle ear where they probably function in host defense. Surfactant has a potential for use in the treatment of OM due to surface tension lowering function in the ET, and the possible immune functions of SP-D and SP-A in the middle ear and ET.

The ECRG4 cleavage product augurin binds the endotoxin receptor and influences the innate immune response during otitis media

Otitis media (OM), the most common disease of childhood, is typically characterized by bacterial infection of the middle ear (ME). Prominent features of OM include hyperplasia of the ME mucosa, which transforms from a monolayer of simple squamous epithelium with minimal stroma into a full-thickness respiratory epithelium in 2-3 days after infection. Analysis of the murine ME transcriptome during OM showed down-regulation of the tumor suppressor gene Ecrg4 that was temporally related to mucosal hyperplasia and identified stromal cells as the primary ECRG4 source. The reduction in Ecrg4 gene expression coincided with the cleavage of ECRG4 protein to release an extracellular fragment, augurin. The duration of mucosal hyperplasia during OM was greater in Ecrg4 ^-/- mice, the number of infiltrating macrophages was enhanced, and ME infection cleared more rapidly. ECRG4-null macrophages showed increased bacterial phagocytosis. Co-immunoprecipitation identified an association of augurin with TLR4, CD14 and MD2, the components of the lipopolysaccharide (LPS) receptor. The results suggest that full-length ECRG4 is a sentinel molecule that potentially inhibits growth of the ME stroma. Processing of ECRG4 protein during inflammation, coupled with a decline in Ecrg4 gene expression, also influences the behavior of cells that do not express the gene, limiting the production of growth factors by epithelial and endothelial cells, as well as the activity of macrophages.

Etiology, Diagnosis, Complications, and Management of Acute Otitis Media in Children

Acute otitis media (AOM) is the most common infectious disease encountered by children under the age of two years and the most common cause of antibiotic use in children in the United States. AOM causes irritability, sleeplessness, decreased appetite, imbalance, and dizziness in patients, especially young children. This assessment was conducted to measure the effectiveness of surgical interventions in treating AOM. We reviewed the present findings regarding the etiology, clinical presentations, diagnosis, treatment, and surgical treatment of complications of AOM. Pain associated with AOM (otalgia) can be severe enough to cause parents to seek treatment for their infants or children. Various suggested measures have been used to treat AOM; antibiotic treatment with amoxicillin is still the treatment of choice for AOM, yet other antibiotics may be used in cases of allergy to penicillin or recent use of amoxicillin. Surgical intervention has been introduced and studied as a diagnostic, therapeutic, and preventive measure for AOM; nevertheless, a few studies have shown that surgical interventions are beneficial in treating and preventing AOM compared to the common practice of using antibiotics. Overdiagnosis of AOM is widespread, leading to injudicious antibiotic use, which contributes to antibiotic resistance. Further management should be determined together with the parent, particularly if observation is the primary intervention.

Distribution and Antimicrobial Resistance Profiles of Bacterial Aetiologies of Childhood Otitis Media in Accra, Ghana

Background:

Otitis media (OM), also known as middle ear infection, is a clinically significant childhood disease. In sub-Saharan Africa, there is a paucity of contemporary reports on it is bacterial aetiologies and antimicrobial resistance among them.

Aim:

To investigate the OM bacterial aetiologies and their antimicrobial resistance patterns among children visiting the Ear, Nose, and Throat clinics of 3 healthcare facilities in Accra, Ghana – Princess Marie Louise Children’s Hospital, 37 Military Hospital, and Mamprobi Hospital.

Methods:

This cross-sectional study involved 100 children below 13 years old with suppurative otitis media. Following standard bacteriological methods, sterile ear swabs were used to take middle ear discharges from the study participants for culture and antimicrobial susceptibility testing. A standard questionnaire was also used to collect data on socio-demographic and clinical characteristics.

Results:

The major OM bacterial aetiologies were Pseudomonas aeruginosa (38.5%), Klebsiella pneumoniae (19.8%), Proteus mirabilis (11.5%), and Staphylococcus aureus (10.4%). The majority of the bacteria demonstrated low to moderate resistance (0%-33.3%) to most of the antibiotics. Eight of the bacteria (4 each of Klebsiella pneumoniae and Escherichia coli) were extended-spectrum beta-lactamase (ESBL) producers; 6 ampicillinase (Amp C)-producing organisms (4 Citrobacter spp. and one each of Morganella morganii and Serratia marcescens) were also identified, and they showed high antibiotic resistance.

Conclusions:

The predominant OM aetiologies were Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus, and they were generally susceptible to most of the antibiotics tested. Amikacin, cefepime, ciprofloxacin, and meropenem could be valuable in the empirical management of childhood OM.

A Retrospective Database Analysis to Estimate the Burden of Acute Otitis Media in Children Aged <15 Years in the Veneto Region (Italy)

This study aimed to assess trends in the incidence of acute otitis media (AOM), a common childhood condition, following the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in the Veneto region of Italy in 2010. AOM episodes (overall, simple, and recurrent (≥3 or ≥4 episodes in 6 or 12 months, respectively, with ≥1 episode in the preceding 6 months)) in children <15 years of age were identified in Pedianet from 2010−2017. Interrupted time series analyses were conducted to assess changes in the annual incidence rates (IRs) in early (2010−2013) and late (2014−2017) PCV13 periods. In total, 72,570 children (402,868 person-years) were identified; 21,048 had 41,683 AOM episodes. Mean annual AOM IR was 103/1000 person-years (95% confidence interval: 102−104), decreasing from 126 to 79/1000 person-years. AOM IRs were highest in children 2−4 years of age, followed by <2 and 5−14 years of age. Overall and simple AOM IRs decreased among children 0−14 years of age, including 2−4 and 5−14 years of age, while recurrent AOM IRs decreased in children <2 years of age. Following PCV13 introduction, AOM IRs decreased substantially in children <15 years of age, with the greatest benefit observed in older children, driven by a reduction in simple AOM IRs. AOM disease burden remains substantial.

Predominant Bacterial and Viral Otopathogens Identified Within the Respiratory Tract and Middle Ear of Urban Australian Children Experiencing Otitis Media Are Diversely Distributed

Background

Otitis media (OM) is one of the most common infections in young children, arising from bacterial and/or viral infection of the middle ear. Globally, Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are the predominant bacterial otopathogens. Importantly, common upper respiratory viruses are increasingly recognized contributors to the polymicrobial pathogenesis of OM. This study aimed to identify predominant bacteria and viruses in the nasopharynx, adenoids and middle ears of peri-urban/urban South-East Queensland Australian children, with and without clinical history of chronic otitis media with effusion (COME) and/or recurrent acute otitis media (RAOM).

Methods

Sixty children, 43 diagnosed with OM and 17 controls with no clinical history of OM from peri-urban/urban South-East Queensland community were recruited to the study. Respiratory tract bacterial and viral presence were examined within nasopharyngeal swabs (NPS), middle ear effusions (MEE) and adenoids, using real-time polymerase chain reaction (RT-PCR) and bacterial culture.

Results

At least one otopathogen present was observed in all adenoid samples, 86.1% and 82.4% of NPS for children with and without OM, respectively, and 47.1% of the MEE from the children with OM. NTHi was the most commonly detected bacteria in both the OM and control cohorts within the adenoids (90.0% vs 93.8%), nasopharynx (67.4% vs 58.8%) respectively, and in the MEE (OM cohort 25.9%). Viruses were detected in all adenoid samples, 67.4% vs 47.1% of the NPS from the OM and control cohorts, respectively, and 37% of the MEE. Rhinovirus was the predominant virus identified in the adenoids (85.0% vs 68.8%) and nasopharynx (37.2% vs 41.2%) from the OM and control cohorts, respectively, and the MEE (19.8%).

Conclusions

NTHi and rhinovirus are predominant otopathogens within the upper respiratory tract of children with and without OM from peri-urban and urban South-East Queensland, Australia. The presence of bacterial otopathogens within the middle ear is more predictive of concurrent URT infection than was observed for viruses, and the high otopathogen carriage within adenoid tissues confirms the complex polymicrobial environment in children, regardless of OM history.

HB-EGF Plays a Pivotal Role in Mucosal Hyperplasia During Otitis Media Induced by a Viral Analog

Otitis media (OM), the most common childhood illness, can be caused by bacterial and/or viral infection. Hyperplasia of the middle ear (ME) mucosa is an important component of OM that contributes to its deleterious sequelae. Our previous research revealed that ME mucosal hyperplasia in bacterially induced OM was associated with expression of the heparin-binding epidermal growth factor (HB-EGF) gene, and that HB-EGF induced the proliferation of ME mucosal explants in culture. We used single-cell RNA-Seq to identify ME cells that express Hbegf and related genes involved in mediating responses to this factor. To determine the degree to which a viral infection might induce mucosal hyperplasia, and to assess the role of HB-EGF in hyperplasia in vivo, we used, Poly(I:C) to simulate a ME viral infection, Western blotting to confirm ME protein expression, and a specific inhibitor to block the effects of HB-EGF during OM. Genes for HB-EGF and its receptor were expressed in the ME primarily by epithelial, stromal and endothelial cells. Poly(I:C) induced prominent ME mucosal hyperplasia, peaking two days after ME injection. Immunostaining revealed that cleavage of proHB-EGF into its soluble form (sHB-EGF) was strongly induced in response to Poly(I:C). Inhibition of the sHB-EGF receptor dramatically reduced the hyperplastic response of the mucosa. The results demonstrate that a synthetic analog of viral double-stranded RNA interaction can induce OM including a strong proliferative response of the ME mucosa, independent of bacteria. They also indicate that HB-EGF is the dominant growth factor responsible for ME mucosal hyperplasia in vivo.

Clinical Practice Guideline: Tympanostomy Tubes in Children (Update)

OBJECTIVE

Insertion of tympanostomy tubes is the most common ambulatory surgery performed on children in the United States. Tympanostomy tubes are most often inserted because of persistent middle ear fluid, frequent ear infections, or ear infections that persist after antibiotic therapy. All these conditions are encompassed by the term otitis media (middle ear inflammation). This guideline update provides evidence-based recommendations for patient selection and surgical indications for managing tympanostomy tubes in children. The guideline is intended for any clinician involved in managing children aged 6 months to 12 years with tympanostomy tubes or children being considered for tympanostomy tubes in any care setting as an intervention for otitis media of any type. The target audience includes specialists, primary care clinicians, and allied health professionals.

PURPOSE

The purpose of this clinical practice guideline update is to reassess and update recommendations in the prior guideline from 2013 and to provide clinicians with trustworthy, evidence-based recommendations on patient selection and surgical indications for managing tympanostomy tubes in children. In planning the content of the updated guideline, the guideline update group (GUG) affirmed and included all the original key action statements (KASs), based on external review and GUG assessment of the original recommendations. The guideline update was supplemented with new research evidence and expanded profiles that addressed quality improvement and implementation issues. The group also discussed and prioritized the need for new recommendations based on gaps in the initial guideline or new evidence that would warrant and support KASs. The GUG further sought to bring greater coherence to the guideline recommendations by displaying relationships in a new flowchart to facilitate clinical decision making. Last, knowledge gaps were identified to guide future research.

METHODS

In developing this update, the methods outlined in the American Academy of Otolaryngology-Head and Neck Surgery Foundation's "Clinical Practice Guideline Development Manual, Third Edition: A Quality-Driven Approach for Translating Evidence Into Action" were followed explicitly. The GUG was convened with representation from the disciplines of otolaryngology-head and neck surgery, otology, pediatrics, audiology, anesthesiology, family medicine, advanced practice nursing, speech-language pathology, and consumer advocacy.

ACTION STATEMENTS

The GUG made strong recommendations for the following KASs: (14) clinicians should prescribe topical antibiotic ear drops only, without oral antibiotics, for children with uncomplicated acute tympanostomy tube otorrhea; (16) the surgeon or designee should examine the ears of a child within 3 months of tympanostomy tube insertion AND should educate families regarding the need for routine, periodic follow-up to examine the ears until the tubes extrude.The GUG made recommendations for the following KASs: (1) clinicians should not perform tympanostomy tube insertion in children with a single episode of otitis media with effusion (OME) of less than 3 months' duration, from the date of onset (if known) or from the date of diagnosis (if onset is unknown); (2) clinicians should obtain a hearing evaluation if OME persists for 3 months or longer OR prior to surgery when a child becomes a candidate for tympanostomy tube insertion; (3) clinicians should offer bilateral tympanostomy tube insertion to children with bilateral OME for 3 months or longer AND documented hearing difficulties; (5) clinicians should reevaluate, at 3- to 6-month intervals, children with chronic OME who do not receive tympanostomy tubes, until the effusion is no longer present, significant hearing loss is detected, or structural abnormalities of the tympanic membrane or middle ear are suspected; (6) clinicians should not perform tympanostomy tube insertion in children with recurrent acute otitis media who do not have middle ear effusion in either ear at the time of assessment for tube candidacy; (7) clinicians should offer bilateral tympanostomy tube insertion in children with recurrent acute otitis media who have unilateral or bilateral middle ear effusion at the time of assessment for tube candidacy; (8) clinicians should determine if a child with recurrent acute otitis media or with OME of any duration is at increased risk for speech, language, or learning problems from otitis media because of baseline sensory, physical, cognitive, or behavioral factors; (10) the clinician should not place long-term tubes as initial surgery for children who meet criteria for tube insertion unless there is a specific reason based on an anticipated need for prolonged middle ear ventilation beyond that of a short-term tube; (12) in the perioperative period, clinicians should educate caregivers of children with tympanostomy tubes regarding the expected duration of tube function, recommended follow-up schedule, and detection of complications; (13) clinicians should not routinely prescribe postoperative antibiotic ear drops after tympanostomy tube placement; (15) clinicians should not encourage routine, prophylactic water precautions (use of earplugs or headbands, avoidance of swimming or water sports) for children with tympanostomy tubes.The GUG offered the following KASs as options: (4) clinicians may perform tympanostomy tube insertion in children with unilateral or bilateral OME for 3 months or longer (chronic OME) AND symptoms that are likely attributable, all or in part, to OME that include, but are not limited to, balance (vestibular) problems, poor school performance, behavioral problems, ear discomfort, or reduced quality of life; (9) clinicians may perform tympanostomy tube insertion in at-risk children with unilateral or bilateral OME that is likely to persist as reflected by a type B (flat) tympanogram or a documented effusion for 3 months or longer; (11) clinicians may perform adenoidectomy as an adjunct to tympanostomy tube insertion for children with symptoms directly related to the adenoids (adenoid infection or nasal obstruction) OR in children aged 4 years or older to potentially reduce future incidence of recurrent otitis media or the need for repeat tube insertion.

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.

The adult microbiome of healthy and otitis patients: Definition of the core healthy and diseased ear microbiomes

Otitis media (OM) and externa (OE) are painful, recurrent ear conditions. As most otitis publications focus on the bacterial content of childhood ears, there remains a dearth of information regarding the adult ear microbiome including both bacteria and fungi. This study compares the outer ear microbiome of healthy adults to adults affected by OE and OM using both intergenic-transcribed-spacer (ITS) and 16S-rDNA sequencing. The adult ear core microbiome consists of the prokaryote Cutibacterium acnes and the eukaryotic Malassezia arunalokei, M. globosa, and M. restricta. The healthy ear mycobiome is dominated by Malassezia and can be divided into two groups, one dominated by M. arunalokei, the other by M. restricta. Microbiome diversity and biomass varied significantly between healthy and diseased ears, and analyses reveal the presence of a potential mutualistic, protective effect of Malassezia species and C. acnes. The healthy ear core microbiome includes the bacteria Staphylococcus capitis and S. capitis/caprae, while the diseased ear core is composed of known bacterial and fungal pathogens including Aspergillus sp., Candida sp., Pseudomonas aeruginosa, S. aureus, and Corynebacterium jeikeium. The data presented highlight the need for early detection of the cause of otitis to direct more appropriate, efficient treatments. This will improve patient outcomes and promote improved antimicrobial stewardship.

Leukotriene B4 Is a Major Determinant of Leukocyte Recruitment During Otitis Media

Background

Pathogens of otitis media (OM) induce inflammatory responses in the middle ear (ME), characterized by mucosal hyperplasia, leukocyte infiltration, and inflammatory mediators, including arachidonic acid metabolites. We studied the role of the eicosanoid leukotriene B4 (LTB4) in OM.

Methods

Expression of LTB4-related genes was evaluated by gene array and single-cell RNA-Seq in MEs infected with nontypeable Haemophilus influenzae (NTHi). An inhibitor of LTB4 receptor 1 (i.e. U75302) was also used to block LTB4 responses.

Results

ME expression of LTB4-related genes was observed by gene arrays and scRNA-Seq. However, not all genes involved in LTB4 generation occurred in any one specific cell type. Moreover, LTB4 receptor inhibition significantly reduced mucosal hyperplasia and virtually eliminated leukocyte infiltration.

Conclusions

ME expression of LTB4-related genes suggest a functional role in OM disease. The fact that LTB4-generation is spread across different cell types is consistent with a transcellular pathway of eicosanoid biosynthesis involving cell-to-cell signaling as well as transfer of biosynthetic intermediates between cells. The dramatic reduction in ME leukocyte infiltration caused by U75302 indicates that LTB4 plays a major role in ME inflammatory cell recruitment, acting via the LTB4R1 receptor. Given that there are many other chemotactic factors that occur in the ME during OM, the ability of LTB4 to activate leukocytes and stimulate their extravasation may explain the effects of inhibition. Reduction in mucosal hyperplasia due to U75302 administration may be secondary to the reduction in leukocytes since LTB4R1 is not expressed by mucosal epithelial or stromal cells. The results suggest that LTB4 receptor antagonists could be useful in treating OM.

Silver Nanoparticles as an Effective Antimicrobial against Otitis Media Pathogens

Otitis Media (OM) is the most common reason for U.S. children to receive prescribed oral antibiotics, leading to potential to cause antibiotic resistance. To minimize oral antibiotic usage, we developed polyvinylpyrrolidone-coated silver nanoparticles (AgNPs-PVP), which completely eradicated common OM pathogens, i.e., Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) at 1.04μg/mL and 2.13μg/mL. The greater antimicrobial efficacy against S. pneumoniae was a result of the H2O2-producing ability of S. pneumoniae and the known synergistic interactions between H2O2 and AgNPs. To enable the sustained local delivery of AgNPs-PVP (e.g., via injection through perforated tympanic membranes), a hydrogel formulation of 18%(w/v)P407 was developed. Reverse thermal gelation of the AgNPs-PVP-P407 hydrogel could gel rapidly upon entering the warm auditory bullae and thereby sustained release of antimicrobials. This hydrogel-based local delivery system completely eradicated OM pathogens in vitro without cytotoxicity, and thus represents a promising strategy for treating bacterial OM without relying on conventional antibiotics.

Safety, Immunogenicity, Efficacy and Effectiveness of Inactivated Influenza Vaccines in Healthy Pregnant Women and Children Under 5 Years: An Evidence-Based Clinical Review

Annual influenza vaccination is often recommended for pregnant women and young children to reduce the risk of severe influenza. However, most studies investigating the safety, immunogenicity, and efficacy or effectiveness of influenza vaccines are conducted in healthy adults. In this evidence-based clinical review, we provide an update on the safety profile, immunogenicity, and efficacy/effectiveness of inactivated influenza vaccines (IIVs) in healthy pregnant women and children <5 years old. Six electronic databases were searched until May 27, 2021. We identified 3,731 articles, of which 93 met the eligibility criteria and were included. The IIVs were generally well tolerated in pregnant women and young children, with low frequencies of adverse events following IIV administration; however, continuous vaccine safety monitoring systems are necessary to detect rare adverse events. IIVs generated good antibody responses, and the seroprotection rates after IIVs were moderate to high in pregnant women (range = 65%-96%) and young children (range = 50%-100%), varying between the different influenza types/subtypes and seasons. Studies show vaccine efficacy/effectiveness values of 50%-70% in pregnant women and 20%-90% in young children against lab-confirmed influenza, although the efficacy/effectiveness depended on the study design, host factors, vaccine type, manufacturing practices, and the antigenic match/mismatch between the influenza vaccine strains and the circulating strains. Current evidence suggests that the benefits of IIVs far outweigh the potential risks and that IIVs should be recommended for pregnant women and young children.

Encouraging rational antibiotic prescribing behaviour in primary care - prescribing practice among children aged 0-4 years 2016-2018: an observational study

OBJECTIVE

To study antibiotic prescriptions among 0- to 4-year-old children before and after implementing a quality project on prudent prescribing of antibiotics in primary healthcare in the capital region of Iceland.

DESIGN

An observational, descriptive, retrospective study using quantitative methodology.

SETTING

Primary healthcare in the Reykjavik area with a total population of approximately 220,000.

SUBJECTS

A total of 6420 children 0-4 years of age presenting at the primary healthcare centres in the metropolitan area over three years from 2016 to 2018.

MAIN OUTCOME MEASURES

Reduction of antibiotic prescriptions and change in antibiotic profile. Data on antibiotic prescriptions for children 0-4 years of age was obtained from the medical records. Out-of-hours prescriptions were not included in the database.

RESULTS

The number of prescriptions during the study period ranged from 263.6 to 289.6 prescriptions/1000 inhabitants/year. A reduction of 9% in the total number of prescriptions between 2017-2018 was observed. More than half of all prescriptions were for otitis media, followed by pneumonia and skin infections. Amoxicillin accounted for over half of all prescriptions, increasing between 2016 and 2018 by 51.3%. During this period, the prescribing of co-amoxiclav and macrolides decreased by 52.3% and 40.7%, respectively. These changes were significant in all cases, p < 0.0001.

CONCLUSION

The results show an overall decrease in antibiotic prescribing concurrent with a change in the choice of antibiotics prescribed and in line with the recommendations presented in the prescribing guidelines implemented by the Primary Healthcare of the Capital Area, and consistent with the project's goals.Key pointsA substantial proportion of antibiotic prescribing can be considered inappropriate and the antibiotic prescription rate is highest in Iceland of the Nordic countries.After implementing guidance on the treatment of common infections together with feedback on antibiotic prescribing, a decrease in the total number of prescriptions accompanied by a shift in the antibiotic profile was observed.

Relative Humidity Affects Acute Otitis Media Visits of Preschool Children to the Emergency Department

OBJECTIVE

The associations between climate variables and diseases such as respiratory infections, influenza, pediatric seizure, and gastroenteritis have been long appreciated. Infection is the main reason for acute otitis media (AOM) incidence. However, few previous studies explored the correlation between climatic parameters and AOM infections. The most important meteorological factors, temperature, relative humidity, and fine particulate matter (PM2.5), were included in this study. We studied the relationship between these meteorological factors and the AOM visits.

MATERIALS AND METHODS

It was a retrospective cross-sectional study. A linear correlation and a linear regression model were used to explore the AOM visits and meteorological factors.

RESULTS

A total of 7075 emergency department visits for AOM were identified. Relative humidity was found an independent risk factor for the AOM visits in preschool children (regression coefficient = -10.841<0, P = .039 < .05), but not in infants and school-age children. Average temperature and PM2.5 were not correlated with AOM visits.

CONCLUSION

Humidity may have a significant inverse impact on the incidence of AOM in preschool-age children.

Evaluation of Clinical Graded Treatment of Acute Nonsuppurative Otitis Media in Children with Acute Upper Respiratory Tract Infection

Objective

To treat children with acute nonsuppurative otitis media induced by acute upper respiratory tract infection of varying severity and evaluate its therapeutic effects.

Materials and Methods

Patients from the emergency department with acute nonsuppurative otitis media were followed up between September 2015 and December 2018. A total of 420 patients were classified into grades I to III according to tympanic membrane intactness and systemic reactions and treated according to grading.

Results

Grade I patients showed no significant difference in the recovery of acute symptoms whether antibiotics are used or not. Grade II patients, after 3 months of follow-up, showed no tympanic membrane perforation, and 9 cases of binaural B-type children did not improve but were cured by operation. In grade III patients, after treatment for 4 hours in the experimental group 3, the earache subsided, 1 case had tympanic membrane perforation, and the patients recovered after 2 weeks (64/92) and after 3 months (28/92) of drug treatment. After treatment for 4 h in the control group 3, the earache eased, and 3 patients developed tympanic membrane perforation and were treated for 3 months. 4 binaural B-type children did not improve but recovered after surgical treatment.

Conclusion

Grade I patients could be closely followed up by clinical observation. For anti-inflammatory patients with grade II disease, treatment has therapeutic significance. For patients with grade III, some patients still have TMP, but the use of cephalosporin third-generation drugs plus an appropriate amount of hormone therapy is effective in reducing symptoms and tympanic local reactions.

Association of Picornavirus Infections With Acute Otitis Media in a Prospective Birth Cohort Study

BACKGROUND

Human rhinoviruses (HRVs), human enteroviruses (HEVs) and human parechoviruses (HPeVs) have been linked to acute otitis media (AOM). We evaluated this association in a prospective birth cohort setting.

METHODS

A total of 324 healthy infants were followed up from birth to age 3 years. Nasal swab samples were collected at age 3, 6, 12, 18, 24, and 36 months and screened for HRV and HEV using real-time reverse-transcription quantitative polymerase chain reaction. Stool samples were collected monthly and analyzed for HRV, HEV, and HPeV. AOM episodes diagnosed by physicians were reported by parents in a diary. The association of viruses with AOM was analyzed using generalized estimation equations, and their relative contributions using population-attributable risk percentages.

RESULTS

A clear association was found between AOM episodes and simultaneous detection of HEV (adjusted odds ratio for the detection of virus in stools, 2.04; 95% confidence interval, 1.06-3.91) and HRV (1.54; 1.04-2.30). HPeV showed a similar, yet nonsignificant trend (adjusted odds ratio, 1.44; 95% confidence interval, .81-2.56). HRV and HEV showed higher population-attributable risk percentages (25% and 20%) than HPeV (11%).

CONCLUSIONS

HEVs and HRVs may contribute to the development of AOM in a relatively large proportion of cases.

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.

Respiratory Syncytial Virus-associated Acute Otitis Media in Infants and Children

Despite recent declines in the incidence of acute otitis media (AOM), more than 5 million cases and 5-6 million primary AOM visits still occur in young children in the United States, resulting in $4.4 billion direct medical costs annually. Our aims in this review are to describe the role of respiratory syncytial virus (RSV) in the etiology of AOM, discuss the prospect of prevention of RSV-associated AOM through immunization, and suggest future research strategies to assess the impact of immunization on RSV-associated AOM.

A Bacterial Epigenetic Switch in Non-typeable Haemophilus influenzae Modifies Host Immune Response During Otitis Media

Non-typeable Haemophilus influenzae (NTHi) causes multiple diseases of the human airway and is a predominant bacterial pathogen of acute otitis media and otitis media in which treatment fails. NTHi utilizes a system of phase variable epigenetic regulation, termed the phasevarion, to facilitate adaptation and survival within multiple sites of the human host. The NTHi phasevarion influences numerous disease-relevant phenotypes such as biofilm formation, antibiotic resistance, and opsonization. We have previously identified an advantageous selection for a specific phasevarion status, which significantly affects severity and chronicity of experimental otitis media. In this study, we utilized pure cultures of NTHi variants in which modA was either locked ON or locked OFF, and thus modA was unable to phase vary. These locked variants were used to assess the progression of experimental otitis media and define the specific immune response induced by each subpopulation. Although the initial disease caused by each subpopulation was similar, the immune response elicited by each subpopulation was unique. The modA2 OFF variant induced significantly greater activation of macrophages both in vitro and within the middle ear during disease. In contrast, the modA2 ON variant induced a greater neutrophil extracellular trap response, which led to greater killing of the modA2 ON variant. These data suggest that not only does the NTHi phasevarion facilitate adaptation, but also allows the bacteria to alter immune responses during disease. Understanding these complex bacterial-host interactions and the regulation of bacterial factors responsible is critical to the development of better diagnostic, treatment, and preventative strategies for these bacterial pathogens.

Inpatient Treatment of Acute Otitis Media at a Pediatric Hospital: A Missed Teaching Opportunity for Antimicrobial Stewardship

BACKGROUND

Acute otitis media (AOM) is a common pediatric condition known to contribute to excessive antibiotic use in the outpatient setting. Treatment of AOM in the inpatient setting has not been described. The objective was to describe the clinical features and inpatient management of AOM to harness this entity to teach learners about judicious antibiotic prescribing in all settings.

METHODS

This is a single-center retrospective cohort study of inpatients treated for AOM from January 2015 to December 2018. Patients were included if they had an antibiotic ordered and either a provider-selected order indication of otitis media or an International Classification of Diseases, 10th Revision billing code of AOM. A chart review was performed to identify primary diagnoses, examination features, and treatment, including excess days of therapy.

RESULTS

We included 840 hospitalized patients treated for AOM in this study. At least 71% of patients had a concurrent viral respiratory illness. Examinations were frequently discordant (34%), and 47% lacked documentation of a physical examination finding of a bulging tympanic membrane, contributing to 3417 potential excess days of therapy. Of the total patients treated for AOM, 40% were given excess duration of therapy. The vast majority (97%) of patients who qualified for a wait-and-watch approach were treated.

CONCLUSIONS

AOM is not being rigorously diagnosed or treated in a guideline-adherent manner in the inpatient setting. This is a lost opportunity for teaching antibiotic stewardship. Interventions, such as promoting the wait-and-watch approach and deferring treatment decisions to inpatient providers, could help promote the judicious use of antibiotics.

Nontypeable Haemophilus influenzae Responds to Virus-Infected Cells with a Significant Increase in Type IV Pilus Expression

Nontypeable Haemophilus influenzae (NTHI) is the predominant bacterial causative agent of many chronic and recurrent diseases of the upper and lower respiratory tracts. NTHI-induced chronic rhinosinusitis, otitis media, and exacerbations of cystic fibrosis and chronic obstructive pulmonary disease often develop during or just after an upper respiratory tract viral infection. We have developed a vaccine candidate immunogen for NTHI-induced diseases that targets the majority subunit (PilA) of the type IV twitching pilus (T4P), which NTHI uses to adhere to respiratory tract epithelial cells and that also plays a role in disease. Here, we showed that NTHI cocultured with virus-infected respiratory tract epithelial cells express significantly more of the vaccine-targeted T4P than NTHI that encounters mock-infected (healthy) cells. These results strongly suggest that a vaccine strategy that targets the NTHI T4P will be effective under the most common predisposing condition: when the human host has a respiratory tract virus infection.

Nontypeable Haemophilus influenzae (NTHI) colonizes the human nasopharynx, but when the host immune response is dysregulated by upper respiratory tract (URT) virus infection, NTHI can gain access to more distal airway sites and cause disease. The NTHI type IV pilus (T4P) facilitates adherence, benign colonization, and infection, and its majority subunit PilA is in clinical trials as a vaccinogen. To further validate the strategy of immunization with PilA against multiple NTHI-induced diseases, it is important to demonstrate T4P expression under microenvironmental conditions that predispose to NTHI infection of the airway. Because URT infection commonly facilitates NTHI-induced diseases, we examined the influence of ongoing virus infection of respiratory tract epithelial cells on NTHI T4P expression in vitro. Polarized primary human airway epithelial cells (HAEs) were sequentially inoculated with one of three common URT viruses, followed by NTHI. Use of a reporter construct revealed that NTHI upregulated pilA promoter activity when cultured with HAEs infected with adenovirus (AV), respiratory syncytial virus (RSV), or rhinovirus (RV) versus that in mock-infected HAEs. Consistent with these results, pilA expression and relative PilA/pilin abundance, as assessed by quantitative reverse transcription-PCR (qRT-PCR) and immunoblot, respectively, were also significantly increased when NTHI was cultured with virus-infected HAEs. Collectively, our data strongly suggest that under conditions of URT virus infection, PilA vaccinogen induction of T4P-directed antibodies is likely to be highly effective against multiple NTHI-induced diseases by interfering with T4P-mediated adherence. We hypothesize that this outcome could thereby limit or prevent the increased load of NTHI in the nasopharynx that characteristically precedes these coinfections.

IMPORTANCE Nontypeable Haemophilus influenzae (NTHI) is the predominant bacterial causative agent of many chronic and recurrent diseases of the upper and lower respiratory tracts. NTHI-induced chronic rhinosinusitis, otitis media, and exacerbations of cystic fibrosis and chronic obstructive pulmonary disease often develop during or just after an upper respiratory tract viral infection. We have developed a vaccine candidate immunogen for NTHI-induced diseases that targets the majority subunit (PilA) of the type IV twitching pilus (T4P), which NTHI uses to adhere to respiratory tract epithelial cells and that also plays a role in disease. Here, we showed that NTHI cocultured with virus-infected respiratory tract epithelial cells express significantly more of the vaccine-targeted T4P than NTHI that encounters mock-infected (healthy) cells. These results strongly suggest that a vaccine strategy that targets the NTHI T4P will be effective under the most common predisposing condition: when the human host has a respiratory tract virus infection.

Bacterial otitis media in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Otitis media is inflammation of the middle ear, comprising a spectrum of diseases. It is the commonest episode of infection in children, which often occurs after an acute upper respiratory tract infection. Otitis media is ranked as the second most important cause of hearing loss and the fifth global burden of disease with a higher incidence in developing worlds like Sub-Saharan Africa and South Asia. Therefore, this systematic review is aimed to quantitatively estimate the current status of bacterial otitis media, bacterial etiology and their susceptibility profile in sub-Saharan Africa.

METHODS

A literature search was conducted from major databases and indexing services including EMBASE (Ovid interface), PubMed/MEDLINE, Google Scholar, ScienceDirect, Cochrane Library, WHO African Index-Medicus and others. All studies (published and unpublished) addressing the prevalence of otitis media and clinical isolates conducted in sub-Saharan Africa were included. Format prepared in Microsoft Excel was used to extract the data and data was exported to Stata version 15 software for the analyses. Der-Simonian-Laird random-effects model at a 95% confidence level was used for pooled estimation of outcomes. The degree of heterogeneity was presented with I2 statistics. Publication bias was presented with funnel plots of standard error supplemented by Begg's and Egger's tests. The study protocol is registered on PROSPERO with reference number ID: CRD42018102485 and the published methodology is available from http://www.crd.york.ac.uk/CRD42018102485.

RESULTS

A total of 33 studies with 6034 patients were included in this study. All studies have collected ear swab/discharge samples for bacterial isolation. The pooled isolation rate of bacterial agents from the CSOM subgroup was 98%, patients with otitis media subgroup 87% and pediatric otitis media 86%. A univariate meta-regression analysis indicated the type of otitis media was a possible source of heterogeneity (p-value = 0.001). The commonest isolates were P. aeruginosa (23-25%), S. aureus (18-27%), Proteus species (11-19%) and Klebsiella species. High level of resistance was observed against Ampicillin, Amoxicillin-clavulanate, Cotrimoxazole, Amoxicillin, and Cefuroxime.

CONCLUSION

The analysis revealed that bacterial pathogens like P. aeruginosa and S. aureus are majorly responsible for otitis media in sub-Saharan Africa. The isolates have a high level of resistance to commonly used drugs for the management of otitis media.

Updated Guidelines for the Management of Acute Otitis Media in Children by the Italian Society of Pediatrics: Treatment

BACKGROUND

New insights into the diagnosis, treatment and prevention of acute otitis media (AOM) have been gained in recent years. For this reason, the Italian Paediatric Society has updated its 2010 guidelines.

METHODS

A literature search was carried out on PubMed. Only pediatric studies published between January 1, 2010 and December 31, 2018 in English or Italian were included. Each included study was assessed according to the GRADE methodology. The quality of the systematic reviews was assessed using AMSTAR 2. The recommendations were formulated by a multidisciplinary panel of experts.

RESULTS

Prompt antibiotic treatment is recommended for children with otorrhea, intracranial complications and/or a history of recurrence and for children under the age of 6 months. For children 6 months to 2 years of age, prompt antibiotic treatment is recommended for all forms of unilateral and bilateral AOM, whether mild or severe. Prompt antibiotic treatment is also recommended for children over 2 years with severe bilateral AOM. A watchful-waiting approach can be applied to children over 2 years with mild or severe unilateral AOM or mild bilateral AOM. High doses of amoxicillin, or amoxicillin-clavulanic acid for patients with a high risk of infection by Beta-lactamase producing strains, remain the first-line antibiotics.

CONCLUSIONS

AOM should be managed on a case-by-case basis that takes account of the child's age, the severity of the episode and whether it is unilateral or bilateral. In patients under 2 years, prompt antibiotic treatment is always recommended.

Comprehensive Detection of Respiratory Bacterial and Viral Pathogens in the Middle Ear Fluid and Nasopharynx of Pediatric Patients With Acute Otitis Media

BACKGROUND

Acute otitis media (AOM) is a common ear infection caused by respiratory viruses and bacteria of the nasopharynx. The present study aimed to detect various respiratory viruses and bacteria in middle ear fluid (MEF) and nasopharyngeal aspirates (NPA) using polymerase chain reaction (PCR).

METHODS

We collected MEF and NPA samples from 122 pediatric patients with AOM. Real-time PCR detected 11 types of respiratory viruses (respiratory syncytial virus A/B, parainfluenza virus 1/2/3, human metapneumovirus, influenza virus A/B, adenovirus, human bocavirus and rhino virus) and 7 types of bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Streptococcus pyogenes, Legionella pneumophila and Moraxella catarrhalis). MEF specimens were also examined using bacterial culture.

RESULTS

At least 1 respiratory viral or bacterial pathogen was detected in MEF of 120 cases (98%) by viral and bacterial PCR and of 93 cases (76%) by viral PCR and bacterial culture. Respiratory viruses were detected in NPA of 84 cases (69%) and MEF of 67 cases (55%). The most common virus detected in MEF was respiratory syncytial virus (21%), followed by parainfluenza virus (15%). All the viruses present in MEF were also detected in NPA specimens. Bacteria were detected by PCR in MEF of 109 cases (89%); H. influenzae was the most frequently detected (65%).

CONCLUSIONS

In many cases, pediatric AOM was found to constitute a respiratory polymicrobial infection. Multiplex PCR was useful to detect multiple respiratory viruses and bacteria in AOM. To understand intractable AOM, further studies regarding the clinical features of each viral and bacterial coinfection are required.

Risk of otitis media with effusion (OME) in children by Pseudomonas aeruginosa

OBJECTIVE

Two third of children in the world experience otitis media with effusion (OME) at least once in their life. According to the importance of knowing OME reason in pediatrics, beside introduced probable bacterial and viral causal agents, Pseudomonas aeruginosa was evaluated either.

METHODS

In this study, 42 middle ear fluid (MEF) samples were collected from pediatrics who confirmed OME by an ears, nose and throat (ENT) specialist. Samples were cultured on bacteriological media for bacterial growth and were either extracted for total DNA and RNA to be tested for introduced bacterial and viral agents with simple and Reverse Transcriptase PCR method within specific primers.

RESULTS

Total results from culture and molecular methods showed that the most prevalent infections were Pseudomonas aeruginosa and streptococcus pneumonia with 33.33% and 14.29% respectively. In total, 66.67% of patients were infected with bacteria, 11.9% with test viruses while in 21.42% of patients no infectious agents were detected. Influenza type A was the only virus was detected.

CONCLUSION

Pseudomonas aeruginosa was the most prevalent agent while mostly detected in patients who were referred from the tropical and humid region. According to these results, it is highly recommended to know the pattern of OME infection in each area separately for more successful treatment.

Genetic characteristics and antibiotic resistance of Haemophilus influenzae isolates from pediatric patients with acute otitis media after introduction of 13-valent pneumococcal conjugate vaccine in Japan

Acute otitis media (AOM) occurs commonly in pediatric populations. We examined resistance genotype, antibiotic susceptibility, quinolone (QL) resistance, and multilocus sequence type (MLST) among Haemophilus influenzae isolates causing AOM following introduction of pneumococcal conjugate vaccines in Japan. The AOM surveillance group included 69 participating otolaryngologists. Causative pathogens isolated from middle ear fluid (MEF) samples collected from 582 children with AOM were identified using both bacterial culture and real-time PCR. H. influenzae isolates among these pathogens were characterized by capsular type, resistance genotype, antibiotic susceptibility, QL resistance, and MLST. In 2016, H. influenzae was identified in 319 samples (54.8%), among which 72.4% (n = 231) tested positive by both culture and PCR; remaining H. influenzae cases were only PCR-positive. This proportion of H. influenzae positivity has increased significantly from 41.2% in 2006 (p < 0.001). Among culture-positive strains, genotypic β-lactamase-nonproducing ampicillin (AMP)-resistant (gBLNAR) strains were frequent (63.2%), with β-lactamase-nonproducing AMP-susceptible (gBLNAS) strains accounting for only 24.2%. Susceptibilities of gBLNAR to oral antimicrobials were best for tosufloxacin, followed by cefditoren and tebipenem; MIC₉₀s were 0.031 μg/mL, 0.5 μg/mL, and 1 μg/mL, respectively. In 7 gBLNAR isolates (3.0%), QL susceptibility was low, owing to amino acid substitutions in GyrA and/or ParC. Sequence types identified numbered 107, including 28 that were new. Prevention of further increases in resistance to antimicrobial agents will require antibiotic selection based on characterization of causative pathogens in clinical practice.

The yield of respiratory viruses detection testing is age-dependent in children with acute otitis media

BACKGROUND

Studies of nasopharyngeal secretions serve as reliable surrogate to evaluate the involvement of viruses in acute otitis media (AOM) and upper/lower respiratory tract infections (URIs/LRIs). We explored nasopharyngeal viral studies from children with uncomplicated AOM and examined their cost-effectiveness in relation to their age.

METHODS

We identified children aged 0-6 years admitted to our pediatrics department in a university-affiliated, secondary hospital with uncomplicated AOM and concurrent URI/LRI between 2012 and 2017, during October-April, when viral studies are performed. Studies were performed either using antigen detection tests, for respiratory syncytial virus (RSV) and influenza A/B (2012-2016) and for a variety of other common respiratory viruses, utilizing multiplex polymerase chain reaction assays (2017).

RESULTS

A total of 249 children were included (median age: 15 months). In 88 (35%) children, viral studies were positive, most of them in children ⩽24 months (78, 89%). RSV was positive in 52 (59%) children, followed by influenza A and B, in 11 (13%) and 5 (6%) children, respectively. First year switch to a molecular assay, 4.5-fold more expensive, resulted in a statistically significant higher yield: 69% positive results in ⩽24 months, and 66% in those aged ⩽12 months (p < 0.05). In those ⩽24 months, US$23 and US$95 were spent for one positive test in the antigen detection years and the polymerase chain reaction year, respectively, whereas in those >24 months, US$83 and US$878 were invested for one positive test in the same year, respectively.

CONCLUSION

In cost-effectiveness terms, the greatest benefit of nasopharyngeal studies was highest in children ⩽24 months.

Characteristics of children with refractory acute otitis media treated at the pediatric emergency department

INTRODUCTION

Refractory acute otitis media (rAOM) is defined as the persistence of signs and symptoms of AOM for more than 48 to 72 hours after the initiation of antibiotic treatment. These patients are often referred to the pediatric emergency department (PED). We sought to study rAOM cases referred to our PED, and to evaluate their clinical characteristics and response to our local management guidelines.

METHODS

A retrospective chart review of all children treated for rAOM between 1/2012-3/2014 was performed. Data recorded included demographics, clinical presentation, antibiotic treatments, need for surgery, and culture results.

RESULTS

A total of 255 patients were included with a mean age of 19 months. Prior to admission, all the children had received at least one course of antibiotics. Amoxicillin was the most common first-line antibiotic prescribed while amoxicillin-clavulanic acid was the most common second and third-line antibiotic given. Intravenous ceftriaxone was the treatment administered at the PED. Myringotomy and pressure equalizing tube (PET) insertion were required in 60% of cases. Middle ear cultures (55 ears) were positive for Streptococcus pneumoniae in two, and Moraxella catarrhalis in only one culture. There were no differences between the mean age of children who had PET insertion and those who did not with regards to fever, rhinorrhea, and preschool or school attendance. Children presenting with otorrhea were less likely to undergo surgery (P = 0.013).

CONCLUSIONS

This is the first study evaluating the established local practice guideline with regards to clinical characteristics and need for surgical management. We showed that myringotomy and PET insertion due to antibiotic failure is commonly performed for cases of rAOM. The majority of the middle ear cultures were sterile.

Infections of the Ear

Infections of the ear are a common presentation to an acute care environment. In this article, the authors aim to summarize the most common presentations, and diagnostic and treatment options for typical infections of the ear. This article is geared toward the emergency physician, urgent care provider, and primary care provider who will likely be the initial evaluating and treating provider to assist them in determining what treatment modalities can be managed in a clinic and what needs to be referred for admission or specialty consultation.

Resistant Streptococcus pneumoniae strains in children with acute otitis media- high risk of persistent colonization after treatment

Background

Despite advances in the development of pneumococcal conjugate vaccines, acute otitis media (AOM) is a common childhood infection, caused mainly by Streptococcus pneumoniae. It has been suggested that persistence of pneumococcal nasopharyngeal carriage is a risk factor for subsequent recurrent infections.

Methods

In this study we evaluate the relationship between 55 pneumococcal strains obtained from nasopharynx/oropharynx (NP/OP) and middle ear fluid (MEF) of 62 children, aged between 1 and 16 years, during AOM (including recurrent/treatment failure AOM, and post-treatment visits), based on their phenotypic and genotypic characteristics performed by analyses of serotype, antibiotic susceptibility patterns and multilocus sequence typing.

Results

S.pneumoniae was isolated from 27.4% of MEF samples; it constituted 43.6% of all positive bacterial samples from MEF samples. There was statistically significant concordance between isolation from the MEF sample and NP/OP colonization by S. pneumoniae (p < 0.0001). During post-treatment visits S.pneumoniae was isolated from 20.8% of children; 91% of them were positive in pneumococcal NP/OP culture during AOM. The serotypes belonging to 10- and 13-valent pneumococcal conjugated vaccines constituted 84% and 92% of the strains, respectively. Multidrug resistance was found in 84% of the strains. According to multivariate analysis, pneumococcal colonization after antibiotic therapy was significantly associated with shorter length of therapy in children with bilateral AOM.

Conclusions

High persistent prevalence of antibiotic-resistant S.pneumoniae strains in children with AOM after unsuccessful bacterial eradication may presumably be regarded as a predisposing factor of infection recurrence.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3398-9) contains supplementary material, which is available to authorized users.

Epigenetic Regulation Alters Biofilm Architecture and Composition in Multiple Clinical Isolates of Nontypeable Haemophilus influenzae

Upper respiratory tract infections are the number one reason for a child to visit the emergency department, and otitis media (middle ear infection) ranks third overall. Biofilms contribute significantly to the chronic nature of bacterial respiratory tract infections, including otitis media, and make these diseases particularly difficult to treat. Several mucosa-associated human pathogens utilize a mechanism of rapid adaptation termed the phasevarion, or phasevariable regulon, to resist environmental and host immune pressures. In this study, we assessed the role of the phasevarion in regulation of biofilm formation by nontypeable Haemophilus influenzae (NTHI), which causes numerous respiratory tract diseases. We found that the NTHI phasevarion regulates biofilm structure and critical biofilm matrix components under disease-specific conditions. The findings of this work could be significant in the design of improved strategies against NTHI infections, as well as diseases due to other pathogens that utilize a phasevarion.

Biofilms play a critical role in the colonization, persistence, and pathogenesis of many human pathogens. Multiple mucosa-associated pathogens have evolved a mechanism of rapid adaptation, termed the phasevarion, which facilitates a coordinated regulation of numerous genes throughout the bacterial genome. This epigenetic regulation occurs via phase variation of a DNA methyltransferase, Mod. The phasevarion of nontypeable Haemophilus influenzae (NTHI) significantly affects the severity of experimental otitis media and regulates several disease-related processes. However, the role of the NTHI phasevarion in biofilm formation is unclear. The present study shows that the phasevarions of multiple NTHI clinical isolates regulate in vitro biofilm formation under disease-specific microenvironmental conditions. The impact of phasevarion regulation was greatest under alkaline conditions that mimic those known to occur in the middle ear during disease. Under alkaline conditions, NTHI strains that express the ModA2 methyltransferase formed biofilms with significantly greater biomass and less distinct architecture than those formed by a ModA2-deficient population. The biofilms formed by NTHI strains that express ModA2 also contained less extracellular DNA (eDNA) and significantly less extracellular HU, a DNABII DNA-binding protein critical for biofilm structural stability. Stable biofilm structure is critical for bacterial pathogenesis and persistence in multiple experimental models of disease. These results identify a role for the phasevarion in regulation of biofilm formation, a process integral to the chronic nature of many infections. Understanding the role of the phasevarion in biofilm formation is critical to the development of prevention and treatment strategies for these chronic diseases.

Etiology of Acute Otitis Media and Characterization of Pneumococcal Isolates After Introduction of 13-Valent Pneumococcal Conjugate Vaccine in Japanese Children

BACKGROUND

Acute otitis media is a leading cause of childhood morbidity and antibiotic prescriptions. We examined etiologic changes in acute otitis media after introduction of 13-valent pneumococcal conjugate vaccine as routine immunization for Japanese children in 2014. Serotypes, resistance genotypes, antibiotic susceptibilities and multilocus sequence typing of pneumococcal isolates were also characterized.

METHODS

Otolaryngologists prospectively collected middle ear fluid from 582 children by tympanocentesis or sampling through a spontaneously ruptured tympanic membrane between June 2016 and January 2017. Causative pathogens were identified by bacterial culture and real-time polymerase chain reaction for bacteria. Serotypes, resistance genotypes, sequence types and susceptibilities to 14 antimicrobial agents were determined for pneumococcal isolates.

RESULTS

At least 1 bacterial pathogen was identified in 473 of the samples (81.3%). Nontypeable Haemophilus influenzae (54.8%) was detected most frequently, followed by Streptococcus pneumoniae (25.4%), Streptococcus pyogenes (2.9%) and others. Pneumococci of current vaccine serotypes have decreased dramatically from 82.1% in 2006 to 18.5% (P < 0.001). Commonest serotypes were 15A (14.8%), 3 (13.9%) and 35B (11.1%). Serotype 3 was significantly less frequent among children receiving 13-valent pneumococcal conjugate vaccine compared with 7-valent pneumococcal conjugate vaccine (P = 0.002). Genotypic penicillin-resistant S. pneumoniae accounted for 28.7%, slightly less than in 2006 (34.2%; P = 0.393); the penicillin-resistant serotypes 15A and 35B had increased. Serotypes 15A, 3 and 35B most often belonged to sequence types 63, 180 and 558.

CONCLUSIONS

Our findings are expected to assist in development of future vaccines, and they underscore the need for appropriate clinical choice of oral agents based on testing of causative pathogens.

Isolation and antimicrobial drug susceptibility pattern of bacterial pathogens from pediatric patients with otitis media in selected health institutions, Addis Ababa, Ethiopia: a prospective cross-sectional study

Background

Otitis media is inflammation of the middle ear and tympanic membrane, which often occurs after an acute upper respiratory tract infection. It is the most common episode of infection in children and the second most important cause of hearing loss affecting 1.23 billion people, thus ranked fifth global burden of disease with a higher incidence in sub-Saharan Africa. Thus, the aim of this study was to determine the isolation rate of bacterial pathogens from pediatric patients with otitis media.

Methodology

Institutional based cross-sectional study was conducted from January 2013–June 2014 in Addis Ababa among 210 pediatrics patients. Demographic, clinical and associated factors data was obtained in face to face interview with guardians/parents by 5 trained nurse data collectors using structured questionnaire. Middle ear drainage swab was collected following all aseptic procedures and transported to the microbiology laboratory. Culture and Antimicrobial sensitivity test were performed according to the standards. The data quality was assured by questionnaire translation, retranslation and pretesting. Reference strains were used as a positive and negative control for biochemical tests, and culture results were cross checked. Data was checked for completeness, consistency and then entered into Epi Info v3.5.1 and analyzed by SPSS v20. Data interpretation was made using graphs, tables, and result statements.

Result

A total of 196 middle ear drainage swab samples were analyzed from pediatric patients and of those 95 (48.5%) samples were positive for pathogenic organisms. The major isolate was S. aureus (15.8%) followed by P. aeruginosa (10.9%), Viridians streptococcus (9.9%), S. pneumoniae (8.9%) and S. pyogenes (7.9%). Upper respiratory tract infection history and living in the rural area have shown significant association with the isolation of pathogenic organism, (p-value = 0.035) and (p-value = 0.003) respectively. Most of the isolates show a high level of resistance to Trimethoprim-Sulfamethoxazole, Penicillin G, Ampicillin, Amoxicillin, and Chloramphenicol.

Conclusion

S. aureus and P. aeruginosa are the most common pathogens that contribute to otitis media as well most of the isolates show a high level of resistance to commonly used drugs to treat otitis media. Therefore, culture and susceptibility testes have paramount importance for the better management of otitis media and drug-resistant infections.

Otitis Media and Nasopharyngeal Colonization in ccl3-/- Mice

We previously found CC chemokine ligand 3 (CCL3) to be a potent effector of inflammation during otitis media (OM): exogenous CCL3 rescues the OM phenotype of tumor necrosis factor-deficient mice and the function of macrophages deficient in several innate immune molecules. To further delineate the role of CCL3 in OM, we evaluated middle ear (ME) responses of ccl3^-/-mice to nontypeable Haemophilus influenzae (NTHi). CCL chemokine gene expression was evaluated in wild-type (WT) mice during the complete course of acute OM. OM was induced in ccl3^-/- and WT mice, and infection and inflammation were monitored for 21 days. Phagocytosis and killing of NTHi by macrophages were evaluated by an in vitro assay. The nasopharyngeal bacterial load was assessed in naive animals of both strains. Many CCL genes showed increased expression levels during acute OM, with CCL3 being the most upregulated, at levels 600-fold higher than the baseline. ccl3^-/- deletion compromised ME bacterial clearance and prolonged mucosal hyperplasia. ME recruitment of leukocytes was delayed but persisted far longer than in WT mice. These events were linked to a decrease in the macrophage capacity for NTHi phagocytosis and increased nasopharyngeal bacterial loads in ccl3^-/- mice. The generalized impairment in inflammatory cell recruitment was associated with compensatory changes in the expression profiles of CCL2, CCL7, and CCL12. CCL3 plays a significant role in the clearance of infection and resolution of inflammation and contributes to mucosal host defense of the nasopharyngeal niche, a reservoir for ME and upper respiratory infections. Therapies based on CCL3 could prove useful in treating or preventing persistent disease.

Streptococcus pneumoniae Otitis Media Pathogenesis and How It Informs Our Understanding of Vaccine Strategies

PURPOSE OF REVIEW

This study aimed to review the literature regarding the mechanisms of transition from asymptomatic colonization to induction of otitis media and how the insight into the pathogenesis of otitis media has the potential to help design future otitis media-directed vaccines.

RECENT FINDINGS

Respiratory viruses have long been shown to predispose individuals to bacterial respiratory infections, such as otitis media. Recent information suggests that Streptococcus pneumoniae, which colonize the nasopharynx asymptomatically, can sense potentially "threatening" changes in the nasopharyngeal environment caused by virus infection by upregulating specific sets of genes involved in biofilm release, dissemination from the nasopharynx to other sites, and protection against the host immune system. Furthermore, an understanding of the transcriptional and proteomic changes occurring in bacteria during transition to infection has led to identification of novel vaccine targets that are disease-specific and will not affect asymptomatic colonization. This approach will avoid major changes in the delicate balance of microorganisms in the respiratory tract microbiome due to elimination of S. pneumoniae.

SUMMARY

Our recent findings are reviewed in the context of the current literature on the epidemiology and pathogenesis of otitis media. We also discuss how other otopathogens, such as Haemophilus influenzae and Moraxella catarrhalis, as well as the normal respiratory microbiome, can modulate the ability of pneumococci to cause infection. Furthermore, the unsatisfactory protection offered by the pneumococcal conjugate vaccines is highlighted and we review potential future strategies emerging to confer a more specific protection against otitis media.

The use of practice guidelines in the management of pediatric cases of Acute Otitis Media in Amman, Jordan

OBJECTIVES

The widespread emergence of antimicrobial resistance has led many healthcare institutions to adopt more conservative antibiotic prescription practice guidelines for the treatment of acute otitis media (AOM). Little is known about the awareness and use of such guidelines by physicians in Jordan. Our aim was to pilot an anonymous survey instrument that would assess AOM treatment trends as well as awareness of and adherence to practice guidelines in Amman. By qualitatively assessing the management of AOM we could illuminate possible disparities in treatment trends, evaluate variability in practice guideline adherence, and help focus efforts of future educational programs that pertain to pediatric AOM management.

METHODS

A total of 71 practicing physicians were anonymously surveyed in Amman, Jordan. The survey assessed awareness of and adherence to practice guidelines by prompting responses to hypothetical AOM cases. Differences in performance between various physician groups were noted.

RESULTS

In total, participants answered 61.2% of the questions correctly. It was found that trainees would prescribe more appropriate antibiotics relative to attending physicians (p = 0.008). It was found that medical physicians followed guidelines more appropriately relative to ENT surgeons (64.2% of questions answered correctly vs. 58.1% of questions answered correctly; p = 0.015) and that physicians who report adhering to guidelines all/most of the time followed guidelines more appropriately relative to those who report adhering only sometimes or never (64.0% of questions answered correctly vs. 58.0% of questions answered correctly; p = 0.011). Also, cases that dealt with children were the most difficult for participants to diagnose as compared with cases that dealt with adults.

CONCLUSION

We conducted the first known qualitative analysis of otitis media practices in Amman and found numerous shortcomings in AOM guideline familiarity. Awareness of practice guidelines can lead to more appropriate AOM management, but there is variability between groups in guideline familiarity and utilization. Interventions that promote more conservative antibiotic prescriptions could be targeted towards groups that prescribe antibiotics less appropriately relative to their colleagues e.g. attending physicians and ENT surgeons. Interventions could also target physicians who manage pediatric AOM cases as participants had the most difficulty in properly diagnosing cases that involved children and infants.

Next-Generation Sequencing Combined with Specific PCR Assays To Determine the Bacterial 16S rRNA Gene Profiles of Middle Ear Fluid Collected from Children with Acute Otitis Media

Although S. pneumoniae, H. influenzae, and M. catarrhalis have been long established as the most important pathogens in acute otitis media using culture and specific PCR assays, the knowledge of their mutual quantitative relations and possible roles of other bacteria is incomplete. The advent of unbiased bacteriome 16S rRNA gene profiling has allowed the detection of nearly all bacteria present in the sample, and it helps in depicting their mutual quantitative ratios. Due to the difficulties in performing mass sequencing in low-volume samples, only a few bacteriome-profiling studies of otitis media have been published, all limited to cases of chronic otitis media. Here, we present a study on samples obtained from young children with acute otitis media, successfully using a strategy of nested PCR coupled with mass sequencing, and demonstrate that the method can confer quantitative information hardly obtainable by other methods.

The aim of the study was to analyze the bacteriome of acute otitis media with a novel modification of next-generation sequencing techniques. Outpatient children with acute otitis media were enrolled in the study, and middle ear fluids were collected during 90 episodes from 79 subjects aged 5 to 42 months (median age, 19 months). The bacteriome profiles of middle ear fluid samples were determined by a nested-PCR amplification of the 16S rRNA gene (V4 region), followed by mass sequencing. The profiling results were compared to the results of specific PCR assays targeting selected prevalent pathogens. Bacteriome profiling using nested amplification of low-volume samples was aided by a bioinformatic subtraction of signal contaminants from the recombinant polymerase, achieving a sensitivity slightly lower than that of specific PCR detection. Streptococcus pneumoniae was detected in 28 (31%) samples, Haemophilus influenzae in 24 (27%), Moraxella catarrhalis in 18 (20%), Staphylococcus spp. in 21 (23%), Turicella otitidis in 5 (5.6%), Alloiococcus otitidis in 3 (3.3%), and other bacteria in 14 (16%) using bacteriome profiling. S. pneumoniae was the dominant pathogen in 14 (16%) samples, H. influenzae in 15 (17%), M. catarrhalis in 5 (5.6%), T. otitidis in 2, and Staphylococcus auricularis in 2. Weaker signals of Prevotella melaninogenica, Veillonella dispar, and Veillonella montpellierensis were noted in several samples. Fourteen samples (16%) were not explainable by bacterial pathogens; novel causative agents were not detected. In conclusion, unbiased bacteriome profiling helped in depicting the true mutual quantitative ratios of ear bacteria, but at present, its complicated protocol impedes its routine clinical use.

IMPORTANCE Although S. pneumoniae, H. influenzae, and M. catarrhalis have been long established as the most important pathogens in acute otitis media using culture and specific PCR assays, the knowledge of their mutual quantitative relations and possible roles of other bacteria is incomplete. The advent of unbiased bacteriome 16S rRNA gene profiling has allowed the detection of nearly all bacteria present in the sample, and it helps in depicting their mutual quantitative ratios. Due to the difficulties in performing mass sequencing in low-volume samples, only a few bacteriome-profiling studies of otitis media have been published, all limited to cases of chronic otitis media. Here, we present a study on samples obtained from young children with acute otitis media, successfully using a strategy of nested PCR coupled with mass sequencing, and demonstrate that the method can confer quantitative information hardly obtainable by other methods.

PRELP Enhances Host Innate Immunity against the Respiratory Tract Pathogen Moraxella catarrhalis

Respiratory tract infections are one of the leading causes of mortality worldwide urging better understanding of interactions between pathogens causing these infections and the host. Here we report that an extracellular matrix component proline/arginine-rich end leucine-rich repeat protein (PRELP) is a novel antibacterial component of innate immunity. We detected the presence of PRELP in human bronchoalveolar lavage fluid and showed that PRELP can be found in alveolar fluid, resident macrophages/monocytes, myofibroblasts, and the adventitia of blood vessels in lung tissue. PRELP specifically binds respiratory tract pathogens Moraxella catarrhalis, Haemophilus influenzae, and Streptococcus pneumoniae, but not other bacterial pathogens tested. We focused our study on M. catarrhalis and found that PRELP binds the majority of clinical isolates of M. catarrhalis (n = 49) through interaction with the ubiquitous surface protein A2/A2H. M. catarrhalis usually resists complement-mediated serum killing by recruiting to its surface a complement inhibitor C4b-binding protein, which is also a ligand for PRELP. We found that PRELP competitively inhibits binding of C4b-binding protein to bacteria, which enhances membrane attack complex formation on M. catarrhalis and thus leads to increased serum sensitivity. Furthermore, PRELP enhances phagocytic killing of serum-opsonized M. catarrhalis by human neutrophils in vitro. Moreover, PRELP reduces Moraxella adherence to and invasion of human lung epithelial A549 cells. Taken together, PRELP enhances host innate immunity against M. catarrhalis through increasing complement-mediated attack, improving phagocytic killing activity of neutrophils, and preventing bacterial adherence to lung epithelial cells.

Viral Upper Respiratory Tract Infections

The upper respiratory system is one of the most common sites of infection for adults, but even more so for children. Several viruses, from variable families, cause upper respiratory infections which, although generally underestimated due to their typically self-limiting nature, underlie enormous healthcare resource utilization and financial burden. Such, otherwise “benign” infections, can have very significant sequelae both in the form of bringing about local complications but also inducing asthma attacks, thus greatly increasing morbidity. Their enormous prevalence also indicates that rigorous research should be undertaken in order to tackle them, in both the prevention and treatment field.

Mechanisms of Changes in Immune Response during Bacterial Coinfections of the Respiratory Tract

Acute diseases of the respiratory tract are often caused by viral pathogens and accompanying secondary bacterial infections. It is known that the development of such bacterial complications is caused mainly by a decreased infiltration with immune system cells and by suppressed inflammation in the lungs. There are significant advances in understanding the mechanisms of secondary infections, although many details remain unclear. This review summarizes current knowledge of the molecular and cellular changes in the host organism that can influence the course of bacterial coinfections in the respiratory tract.

Human enterovirus and rhinovirus infections are associated with otitis media in a prospective birth cohort study

BACKGROUND

Human enteroviruses (HEVs) and rhinoviruses (HRVs) have been linked to acute otitis media (AOM).

OBJECTIVES

The present study evaluates the aforementioned association in a birth cohort setting.

STUDY DESIGN

The cohort included 286 healthy infants (191 boys) followed from birth up to the age of 2 years in the Type 1 Diabetes Prediction and Prevention study in Finland. Stool samples were collected monthly and analyzed for the presence of HRV and HEV RNA using RT-PCR. Clinical symptoms were recorded by a questionnaire every 3-6 months.

RESULTS

Altogether 610 AOM episodes were reported during the follow-up. 9.8% of the stool samples were positive for HRV and 6.8% for HEV. HRV positivity peaked at the age of 3-6 months declining gradually after this age, whereas HEV positivity peaked later, at the age of 12-24 months. The risk of AOM was increased in children who were HEV positive at least once at the age of 6-12 months (OR 2.2 [95%CI 1.1-4.2], P=0.023) or who were HRV positive at least once at the age of 18-24 months (OR 2.3 [95%CI 1.0-5.2], P=0.042). Having an older sibling, short breast-feeding and maternal smoking during pregnancy were also significantly associated with AOM.

CONCLUSIONS

HRV and HEV infections are frequent during the first months of life. The observed trend for increased risk of AOM in HRV and HEV positive children is in line with the results from hospital series suggesting that these viruses may play an independent role in the pathogenesis of AOM.