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The identification of a diverse microbiome in otic secretions from healthy young adults challenged the entrenched dogma of middle ear sterility and underscored previously unknown roles for oral commensals in the seeding of otic biofilms. We gained insights into the selective forces that enrich for specific groups of oral migrants in the middle ear mucosa by investigating the phylogeny and physiology of 19 strains isolated previously from otic secretions and representing otic commensals (Streptococcus) or transient migrants (Staphylococcus, Neisseria and actinobacterial Micrococcus and Corynebacterium). Phylogenetic analyses of full length 16S rRNA sequences recovered from partially sequenced genomes resolved close relationships between the isolates and (peri)oral commensals. Physiological functions that facilitate mucosal colonization (swarming motility, surfactant production) and nutrition (mucin and protein degradation) were also widespread among the cultivars, as was their ability to grow in the presence or absence of oxygen. Yet, streptococci stood out for their enhanced biofilm-forming abilities under oxic and anoxic conditions and ability to ferment host-derived mucosal substrates into lactate, a key metabolic intermediate in the otic trophic webs. Additionally, the otic streptococci inhibited the growth of common otopathogens, an antagonistic interaction that could exclude competitors and protect the middle ear mucosa from infections. These adaptive traits allow streptococcal migrants to colonize the otic mucosa and grow microcolonies with syntrophic anaerobic partners, establishing trophic interactions with other commensals that mirror those formed by the oral ancestors in buccal biofilms.

Alloiococcus otitidis and Turicella otitidis are common bacteria of the human ear. They have frequently been isolated from the middle ear of children with otitis media (OM), though their potential role in this disease remains unclear and confounded due to their presence as commensal inhabitants of the external auditory canal. In this review, we summarize the current literature on these organisms with an emphasis on their role in OM. Much of the literature focuses on the presence and abundance of these organisms, and little work has been done to explore their activity in the middle ear. We find there is currently insufficient evidence available to determine whether these organisms are pathogens, commensals or contribute indirectly to the pathogenesis of OM. However, building on the knowledge currently available, we suggest future approaches aimed at providing stronger evidence to determine whether A. otitidis and T. otitidis are involved in the pathogenesis of OM. Such evidence will increase our understanding of the microbial risk factors contributing to OM and may lead to novel treatment approaches for severe and recurrent disease.

Alloiococcus otitidis and Turicella otitidis are common bacteria of the human ear. They have frequently been isolated from the middle ear of children with otitis media (OM), though their potential role in this disease remains unclear and confounded due to their presence as commensal inhabitants of the external auditory canal. In this review, we summarize the current literature on these organisms with an emphasis on their role in OM. Much of the literature focuses on the presence and abundance of these organisms, and little work has been done to explore their activity in the middle ear. We find there is currently insufficient evidence available to determine whether these organisms are pathogens, commensals or contribute indirectly to the pathogenesis of OM. However, building on the knowledge currently available, we suggest future approaches aimed at providing stronger evidence to determine whether A. otitidis and T. otitidis are involved in the pathogenesis of OM. Such evidence will increase our understanding of the microbial risk factors contributing to OM and may lead to novel treatment approaches for severe and recurrent disease. [ABSTRACT FROM AUTHOR]

Objectives: Bacterial biofilms have been found in the adenoids of children with recurrent acute otitis media (AOM) and persistent otitis media with effusion (OME). However, the possible difference in biofilm-producing bacteria (BPBs) between the adenoid surface at the nasopharyngeal dome (ND) and near the ostium of the eustachian tube (ET) has not been investigated. This study aimed to assess the difference in BPBs between adenoid biopsy specimens of the ND and those taken near the pharyngeal ostium of the ET in children with chronic adenoiditis with recurrent AOM and/or persistent OME. Methods: We collected adenoid biopsy specimens from the ND and ET during transoral endoscopic adenoidectomy to assess BPB by means of spectrophotometric analysis. Results: We collected 135 adenoid biopsy specimens from 45 children. BPBs were detected significantly (p = 0.04) more frequently in the ET samples than in the ND samples, mainly Staphylococcus aureus. Although the prevalence of 5 aureus was slightly greater in the ND samples, and that of Streptococcus pneumoniae and Moraxella catarrhalis was slightly greater in the ET samples, these differences were not statistically significant. Conclusions: The fact that BPBs were significantly more frequently located near the ostium of the ET suggests that the adenoids are a reservoir for bacteria and indicates that hypertrophic adenoids (particularly hypertrophy near the ostium of the ET) play a role in recurrent AOM and/or OME. [ABSTRACT FROM AUTHOR]

The identification of a diverse microbiome in otic secretions from healthy young adults challenged the entrenched dogma of middle ear sterility and underscored previously unknown roles for oral commensals in the seeding of otic biofilms. We gained insights into the selective forces that enrich for specific groups of oral migrants in the middle ear mucosa by investigating the phylogeny and physiology of 19 strains isolated previously from otic secretions and representing otic commensals ( Streptococcus ) or transient migrants ( Staphylococcus, Neisseria and actinobacterial Micrococcus and Corynebacterium ). Phylogenetic analyses of full length 16S rRNA sequences recovered from partially sequenced genomes resolved close relationships between the isolates and (peri)oral commensals. Physiological functions that facilitate mucosal colonization (swarming motility, surfactant production) and nutrition (mucin and protein degradation) were also widespread among the cultivars, as was their ability to grow in the presence or absence of oxygen. Yet, streptococci stood out for their enhanced biofilm-forming abilities under oxic and anoxic conditions and ability to ferment host-derived mucosal substrates into lactate, a key metabolic intermediate in the otic trophic webs. Additionally, the otic streptococci inhibited the growth of common otopathogens, an antagonistic interaction that could exclude competitors and protect the middle ear mucosa from infections. These adaptive traits allow streptococcal migrants to colonize the otic mucosa and grow microcolonies with syntrophic anaerobic partners, establishing trophic interactions with other commensals that mirror those formed by the oral ancestors in buccal biofilms., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Gemma Reguera reports financial support was provided by Office of Naval Research. Kristin J Jacob reports a relationship with Michigan Department of Health and Human Services that includes: non-financial support., (© 2022 The Authors.)

Background: We explored the nasal microbiota in Indigenous Australian children in relation to ear and nasal health., Methods: In total, 103 Indigenous Australian children aged 2-7 years (mean 4.7 years) were recruited from 2 Queensland communities. Children's ears, nose, and throats were examined and upper respiratory tract (URT) swabs collected. Clinical histories were obtained from parents/medical records. URT microbiota were characterized using culturomics with Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification. Real-time PCR was used to quantify otopathogen (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis) loads and detect respiratory viruses. Data were analyzed using beta diversity measures, regression modeling, and a correlation network analysis., Results: Children with historical/current otitis media (OM) or URT infection (URTI) had higher nasal otopathogen detection and loads and rhinovirus detection compared with healthy children (all P < .04). Children with purulent rhinorrhea had higher nasal otopathogen detection and loads and rhinovirus detection (P < .04) compared with healthy children. High otopathogen loads were correlated in children with historical/current OM or URTI, whereas Corynebacterium pseudodiphtheriticum and Dolosigranulum pigrum were correlated in healthy children., Conclusions: Corynebacterium pseudodiphtheriticum and D. pigrum are associated with URT and ear health. The importance of the main otopathogens in URT disease/OM was confirmed, and their role relates to co-colonization and high otopathogens loads., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)