Microbiome of the External Auditory Canal: Changes After Long-Term Hearing Aid Use.

OBJECTIVE: To investigate the microbial changes of long-term hearing aid use culture independently. STUDY DESIGN: Cross-sectional study. PATIENTS: Fifty long-term hearing aid users and 80 volunteer controls with asymptomatic ears. INTERVENTION: External auditory canal (EAC) sampling with DNA-free swabs. MAIN OUTCOME MEASURES: Microbial communities in the samples were investigated with amplicon sequencing of the 16S rRNA gene. RESULTS: The final analysis contained 48 hearing aid users, 59 controls. Twenty-four samples were excluded because of low sequence count, recent use of antimicrobials and/or corticosteroids, recent cold, or missing health status. The groups showed significant differences in bacterial diversity (beta div., p = 0.011), and hearing aid users showed lower species richness than the control group (alpha div., p < 0.01). The most frequent findings in both groups were Staphylococcus auricularis , Alloiococcus otitis , Cutibacterium acnes , Corynebacterium otitidis , and Staphylococcus unclassified sp. Hearing aid users' samples presented more Corynebacterium tuberculostearicum than the control samples. Common EAC pathogens, such as Staphylococcus aureus or Pseudomonas aeruginosa were rare. CONCLUSION: Long-term hearing aid use lowers bacterial diversity and modulates the EAC microbiome. The changes mostly affect commensals. Lowered diversity may predispose individuals to EAC conditions and needs more research.

Laser, radiofrequency or tympanostomy knife? Comparison of surgical methods in tympanostomy treatment of young children and predictive value of tympanometry.

OBJECTIVES: To investigate tympanostomy tube (TT) treatment in young children, with special interest in bloodless surgical methods (laser and radiofrequency), myringosclerosis formation and tympanometric testing. METHODS: This prospective study includes 76 children whose 121 ears with middle ear effusion were treated with tympanostomy tubes. Myringotomy was performed with CO2 laser in 37, radiofrequency in 40 and myringotomy knife in 44 ears. The ears were evaluated with otomicroscopy and tympanometry preoperatively and postoperatively every 3-4 months until spontaneous tube extrusion. RESULTS: All tubes extruded spontaneously (mean 12.8 months, range 3-36 months), with no persistent perforations or cholesteatomas. CO2 laser and radiofrequency inserted tympanostomy tubes extruded faster (mean 11 months) compared to incisional myringotomy (mean 15 months, p = 0.002). Myringosclerosis was noted in 25 (21%) ears after treatment. There was a tendency to less myringosclerosis with bloodless techniques, but the difference was not significant. Flat tympanograms on the day of procedure predicted continuation of ventilation problems also after TT treatment (p = 0.003). Ears with preoperative type B tympanogram had significantly more myringosclerosis 21/75 (28%) compared with type A and C tympanograms 4/41 (10%) (p = 0.032). CONCLUSIONS: While all myringotomy methods were effective and safe, the traditional incisional myringotomy with a tympanostomy knife is still a good, feasible and cost-effective myringotomy method. No surgical removal of tympanostomy tubes is needed before 3 years of uncomplicated tympanostomy treatment. Tympanometry turned out to be a useful tool in prediction of post TT treatment ventilation problems of the middle ear.

Microbiome of the Healthy External Auditory Canal.

OBJECTIVE: To investigate the microbiota of the healthy external auditory canal (EAC) culture-independently and to evaluate the usefulness of the swabbing method in collecting EAC microbiota samples. STUDY DESIGN: Cohort study. PATIENTS: Fifty healthy asymptomatic working-age volunteers. INTERVENTION: Samples were harvested with DNA-free swabs from the volunteers' EACs. MAIN OUTCOME MEASURES: Amplicon sequencing of the 16S rRNA gene was used to characterize the microbial communities in the samples. RESULTS: The swabbing method is feasible for EAC microbiota sample collection. The analyzed 41 samples came from 27 female and 14 male subjects; 4 samples were excluded due to recent antimicrobial treatment and 5 because of low sequence count or suspected contaminant microbes. The four most frequent amplicon sequence variants in the microbiota data were Staphylococcus auricularis, Propionibacterium acnes, Alloiococcus otitis, and Turicella otitidis. Typically, the dominant amplicon sequence variant in a sample was one of the most frequent bacteria, but there were also subjects where the dominant species was not among the most frequent ones. The genus Alloiococcus was least common in females who reported cleaning their ears. Subjects with a high relative abundance of Alloiococcus typically had a low abundance of Staphylococcus, which may be a sign of the two being competing members of the microbial community. CONCLUSIONS: The most common bacteria in the microbiome of the healthy EAC were Staphylococcus auricularis, Propionibacterium acnes, Alloiococcus otitis, and Turicella otitidis. The EAC microbiota seems more diverse and individualized than previously thought. Also, ear cleaning habits seem to alter the EAC microbiome.

Prognostic Value and Changes of Auditory Brain Stem Response in Children With Bacterial Meningitis in Luanda, Angola.

OBJECTIVE: To assess the role of single and repeated auditory brain stem response (ABR) in predicting mortality and severe neurological injury among children having bacterial meningitis (BM) in Luanda, Angola. METHODS: The morphology of ABR traces of 221 children (aged 2 months to 12 years) from admission day was analyzed and compared with age-matched normative data. Absence and delay of traces were compared with mortality and mortality or severe neurological injury in subgroup analyses. Outcome was also evaluated with repeated ABR of 166 children based on presence or absence of responses at 80 dB nHL (normal hearing level) stimulation level. RESULTS: Individually, the absence of typical ABR waveform did not signify poor outcome. At the group level, latencies and interpeak latencies (IPLs) were significantly prolonged among patients with BM in comparison with controls, and the prolongation correlated with higher mortality or severe neurological sequelae. CONCLUSIONS: We confirmed the effect of BM on neural conduction time in auditory pathway. However, ABR in similar settings seems not useful for individual prognostication, although at the group level, delayed latencies, IPLs, or both associated with poorer outcome.