Recurrent acute otitis media (rAOM, recurrent ear infection) is a common childhood disease caused by bacteria termed otopathogens, for which current treatments have limited effectiveness. Generic probiotic therapies have shown promise, but seem to lack specificity. We hypothesised that healthy children with no history of AOM carry protective commensal bacteria that could be translated into a specific probiotic therapy to break the cycle of re-infection. We characterised the nasopharyngeal microbiome of these children (controls) in comparison to children with rAOM (cases) to identify potentially protective bacteria. As some children with rAOM do not appear to carry any of the known otopathogens, we also hypothesised that characterisation of the middle ear microbiome could identify novel otopathogens, which may also guide the development of more effective therapies. Middle ear fluids, middle ear rinses and ear canal swabs from the cases and nasopharyngeal swabs from both groups underwent 16S rRNA gene sequencing. The nasopharyngeal microbiomes of cases and controls were distinct. We observed a significantly higher abundance of Corynebacterium and Dolosigranulum in the nasopharynx of controls. Alloiococcus, Staphylococcus and Turicella were abundant in the middle ear and ear canal of cases, but were uncommon in the nasopharynx of both groups. Gemella and Neisseria were characteristic of the case nasopharynx, but were not prevalent in the middle ear. Corynebacterium and Dolosigranulum are characteristic of a healthy nasopharyngeal microbiome. Alloiococcus, Staphylococcus and Turicella are possible novel otopathogens, though their rarity in the nasopharynx and prevalence in the ear canal means that their role as normal aural flora cannot be ruled out. Gemella and Neisseria are unlikely to be novel otopathogens as they do not appear to colonise the middle ear in children with rAOM.

Abnormal wound repair has been observed in the airway epithelium of patients with chronic respiratory diseases, including asthma. Therapies focusing on repairing vulnerable airways, particularly in early life, present a potentially novel treatment strategy. We report defective lower airway epithelial cell repair to strongly associate with common pre–school-aged and school-aged wheezing phenotypes, characterized by aberrant migration patterns and reduced integrin α5β1 expression. Next generation sequencing identified the PI3K/Akt pathway as the top upstream transcriptional regulator of integrin α5β1, where Akt activation enhanced repair and integrin α5β1 expression in primary cultures from children with wheeze. Conversely, inhibition of PI3K/Akt signaling in primary cultures from children without wheeze reduced α5β1 expression and attenuated repair. Importantly, the FDA-approved drug celecoxib — and its non–COX2-inhibiting analogue, dimethyl-celecoxib — stimulated the PI3K/Akt–integrin α5β1 axis and restored airway epithelial repair in cells from children with wheeze. When compared with published clinical data sets, the identified transcriptomic signature was also associated with viral-induced wheeze exacerbations highlighting the clinical potential of such therapy. Collectively, these results identify airway epithelial restitution via targeting the PI3K–integrin α5β1 axis as a potentially novel therapeutic avenue for childhood wheeze and asthma. We propose that the next step in the therapeutic development process should be a proof-of-concept clinical trial, since relevant animal models to test the crucial underlying premise are unavailable.

Introduction: Intubation is a known risk factor for dysphonia yet is essential in the perinatal care of many very preterm infants. Children born preterm, who are frequently resuscitated with endotracheal intubation, may be at risk of dysphonia at school age and beyond. Objectives: To identify and describe the evidence pertaining to long-term voice outcomes and risk factors for developing dysphonia in preterm children. Results: In addition to case studies and series, three larger-scale studies have reported on dysphonia and voice outcomes in preterm children. Studies reporting treatment outcomes were not available. Factors associated with poor voice outcomes included female gender, birth weight <1,000 g, birth at <27 weeks' gestation, surgical closure of patent ductus arteriosus, emergency versus elective intubations and multiple intubations. Adverse voice outcomes were associated with laryngeal pathology and compensatory supraglottic compression. Conclusions: Dysphonia is a newly reported, long-term complication of preterm birth, yet the number of relevant studies remains limited. Further research is required to confirm the risk factors for developing dysphonia, which will inform future voice treatment studies.

The airway epithelium of children with wheeze is characterized by defective repair that contributes to disease pathobiology. Dysregulation of developmental processes controlled by Notch has been identified in chronic asthma. However, its role in airway epithelial cells of young children with wheeze, particularly during repair, is yet to be determined. We hypothesized that Notch is dysregulated in primary airway epithelial cells (pAEC) of children with wheeze contributing to defective repair. This study investigated transcriptional and protein expression and function of Notch in pAEC isolated from children with and without wheeze. Primary AEC of children with and without wheeze were found to express all known Notch receptors and ligands, although pAEC from children with wheeze expressed significantly lower NOTCH2 (10-fold, p = 0.004) and higher JAG1 (3.5-fold, p = 0.002) mRNA levels. These dysregulations were maintained in vitro and cultures from children with wheeze displayed altered kinetics of both NOTCH2 and JAG1 expression during repair. Following Notch signaling inhibition, pAEC from children without wheeze failed to repair (wound closure rate of 76.9 ± 3.2%). Overexpression of NOTCH2 in pAEC from children with wheeze failed to rescue epithelial repair following wounding. This study illustrates the involvement of the Notch pathway in airway epithelial wound repair in health and disease, where its dysregulation may contribute to asthma development.

Understanding patterns of bacterial carriage and otitis media (OM) microbiology are crucial for assessing vaccine impact and informing policy. The microbiology of OM can vary with geography, time, and interventions like pneumococcal conjugate vaccines (PCVs). We evaluated the microbiology of nasopharyngeal and middle ear effusions in children living in Western Australia, 11 years following the introduction of PCV13. Children undergoing surgery for recurrent acute OM and/or chronic OM with effusion (cases), and children undergoing surgery for non-infectious reasons (controls), were recruited. Nasopharyngeal swabs and middle ear effusions (MEE - cases only) were collected, and quantitative PCR applied for detection of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes. S. pneumoniae-positive MEE were serotyped by culture. Nasopharyngeal swabs from 166 children under 5 years of age (123 cases, 43 controls) and MEE from 103 cases (93 with bilateral effusion - 196 MEE samples) were collected between September 2022 to December 2023. Nasopharyngeal carriage of H. influenzae was more common and density 10 times higher in cases compared to controls (84.2% H. influenzae carriage-positive cases versus 48.9% of controls, p=0.024; mean DNA concentration of 1.8pg/µL versus 0.13pg/µL, p=0.037). S. pneumoniae was more commonly carried in cases (not significant), and carriage density was higher in cases compared to controls (mean pneumococcal DNA concentration of 0.4pg/µL versus 0.09pg/µL, p=0.049). M. catarrhalis carriage and carriage density were similar between cases and controls (82.1% versus 76.7%). Carriage of 2 or more otopathogen species was common (80% of swabs). In the MEE, H. influenzae predominated (53% PCR-positive) followed by M. catarrhalis (31%), S. pneumoniae (22%), S. aureus (6%), S. pyogenes (2%) and P. aeruginosa (2%). Polymicrobial infection was identified in 26% of effusions. Of the S. pneumoniae PCR-positive MEE, 14 specimens from 11 children were culturable and all serotypes were non-PCV13 types. The aetiology of recurrent and/or chronic OM in children continues to be primarily associated with H. influenzae. These data highlight the need for a concerted effort to develop effective preventative strategies for H. influenzae, most notably, nontypeable (NTHi). Higher valency PCVs may impact on pneumococcal OM.

The Australian Aboriginal population experiences disproportionately high rates of otitis media (OM). Streptococcus pneumoniae is one of the main pathogens responsible for OM and currently no vaccine offering cross strain protection exists. Vaccines consisting of conserved antigens to S. pneumoniae may reduce the burden of OM in high-risk populations; however no data exists examining naturally acquired antibody in Aboriginal children with OM. Serum and salivary IgA and IgG were measured against the S. pneumoniae antigens PspA1 and 2, CbpA and Ply in a cross sectional study of 183 children, including 36 non-Aboriginal healthy control children and 70 Aboriginal children and 77 non-Aboriginal children undergoing surgery for OM using a multiplex bead assay. Significant differences were observed between the 3 groups for serum anti-PspA1 IgA, anti-CbpA and anti-Ply IgG and for all salivary antibodies assessed. Aboriginal children with a history of OM had significantly higher antibody titres than non-Aboriginal healthy children with no history of OM and non-Aboriginal children with a history of OM for several proteins in serum and saliva. Non-Aboriginal children with a history of OM had significantly higher salivary anti-PspA1 IgG than healthy children, while all other titres were comparable between the groups. Conserved vaccine candidate proteins from S. pneumoniae induce serum and salivary antibody responses in Aboriginal and non-Aboriginal children with a history of OM. Aboriginal children do not have an impaired antibody response to the antigens measured from S. pneumoniae and they may represent vaccine candidates in Indigenous populations.